MXPA00011571A - Electric motor having snap connection assembly method - Google Patents

Abstract

An electric motor having a snap-together construction without the use of separate fasteners. The construction of the motor removes additive tolerances for a more accurate assembly. The motor is capable of programming and testing after final assembly and can be non-destructively disassembled for repair or modification. The motor is constructed to inhibit the ready entry of water into the motor housing and to limit the effect of any water which manages to enter the housing.

Description

ELECTRIC MOTOR THAT HAS A SPRING CLOSING CONNECTION ASSEMBLY METHOD BACKGROUND OF THE INVENTION This invention relates generally to electric motors and, more particularly, to an electric motor having a simplified, easily assembled construction. The assembly of electric motors requires the assembly of a rotor for rotation relative to a stator, so that magnets are generally aligned on the rotor with one or more windings on the stator. Conventionally, this is done by mounting an arrow of the rotor on a frame, which is attached to the stator. The arrow is received through the stator so that it rotates around the stator axis. The frame or a separate reinforcement can be provided to enclose the stator and the rotor. In addition to these basic engine components, control components are also assembled. An electrically commutated motor can have a printed circuit board assembling several components. The motor assembly requires the electrical connection of the circuit board components to the winding and is also provided for the electrical connection to an external power source. The same circuit board is secured in place, typically through a stator connection with fasteners, or through welding, brazing or joining. Many of these steps are done manually and have important associated material work costs. The fasteners, and any other material used only for connection, are all additional parts that have their own associated costs and time required for assembly. The tolerances of the parts of the electric motor component must be controlled, so that in all assembled motors, the rotor is free to rotate relative to the stator without making contact with the stator. A small air gap between the stator and the magnets on the rotor is preferred to promote the transfer of magnetic flux between the rotor and the stator, while allowing rotation of the rotor. Tolerances in the dimensions of several components can have an effect on the size of the air gap. The tolerances of these components are additive, so that the size of the air gap can be greater than desirable to ensure that the rotor will remain free to rotate on all assembled engines. The number of components that affect the size of the air gap may vary, depending on the engine configuration. Engines are commonly programmed to operate in certain ways desired by the end user of the engine. For example, certain operational parameters must be programmed into the components of the printed circuit board, such as the motor speed, delay before starting the motor, and other parameters. Mass-produced engines are very commonly programmed in the same manner before the final assembly and are not capable of being reprogrammed after assembly. However, the end users of the engine sometimes have different requirements for the operation of the engine. In addition, the end user can change the desired operational parameters of the motor. For this reason, large inventories of engines, or at least programmable circuit boards, are maintained to satisfy the myriad of applications. Electric motors have a myriad of applications, including those that require the motor to work in the presence of water. Water is dangerous to the operation and life of the motor, and it is vital to keep the stator and control circuit system free of water accumulations. It is well known how to make the stator and other components waterproof. However, for mass-produced engines, it is imperative that the cost to prevent water from entering and accumulating in the engine will be kept to a minimum. An additional concern when the engine is used in the cooling area is the formation of ice on the engine. Not commonly, the motor will be disconnected from its power source, or it will be damaged by the formation of ice on electrical connectors connected to the circuit board. Ice that forms between the printed circuit board at the plug connector can push the connector away from the printed circuit board, causing disconnection, or rupture of the board or connector.

COMPENDIUM OF THE INVENTION Among the various objects and features of the present invention, one can observe the provision of an electric motor, which has few component parts; the provision of said engine that does not have fasteners to secure its component parts; the provision of said engine, which can be assembled accurately in a mass production; the provision of said engine having components capable of having tolerances to minimize the effect of additive tolerances; the provision of said motor, which can be re-programmed after the final assembly; the provision of said engine, which inhibits the intrusion of water to the engine; and the provision of said motor, which resists the damage and the malfunction in operations at a lower temperature. Among the various objects and features of the present invention, one can observe the provision of a method for assembling an electric motor, which requires few steps and minimal work; the provision of a method that minimizes the number of connections that must be made; the provision of a method that minimizes the effect of additive tolerances; the provision of a method that allows programming and testing after the final assembly; and the provision of a method that is easy to use.

Generally, an assembly method of an electric motor of the present invention comprises forming a stator including a stator core and a winding positioned around the stator core and forming a rotor including an arrow. A housing is formed, which is adapted to support and at least partially enclose the stator and the rotor. The rotor is mounted on the stator by inserting the arrow through the stator to rotate relative to the stator about a longitudinal axis of the rotor shaft. The stator / rotor subassembly thus formed is connected by jump to the housing. In another aspect of the present invention, an electric motor generally comprises a stator including a stator core, a winding on the stator core, and a first connector element per jump. A rotor including an arrow is received in the stator core for rotation of the rotor relative to the stator about the longitudinal axis of the arrow. A housing adapted to support the stator and the rotor has a second jump connector member formed therein. The first jump connector element is coupled to the second jump connector element to connect the stator and the rotor to the housing. Other objects and features of the present invention will be partly evident and partly pointed out below.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an exploded elevation view of an electric motor in the form of a fan.

Figure 2 is an exploded perspective view of parts of the stator component of the engine. Figure 3 is a vertical cross-sectional view of the assembled motor. Figure 4 is the stator and an exploded printed circuit board from its installed position on the stator. Figure 5 is a fragmentary, enlarged view of the reinforcement of Figure 1 as viewed from the right side. Figure 6 is a side elevation view of a central locator member and a rotor shaft bearing. Figure 7 is a view in extreme right elevation thereof. Figure 8 is a longitudinal section of the locator member and the bearing. Figure 9 is an end view of a stator core of the stator with the central locator member and pole pieces positioned by the locator member shown in faded lines. Figure 10 is an opposite end view of the stator core. Figure 11 is a section taken in the plane including line 11-11 of Figure 10. Figure 12 is a fragmentary, greatly enlarged view of the engine at the junction of a rotor hub with the stator. Figure 13 is a section taken in the plane including line 13-13 of Figure 5, showing the printed circuit board in faded lines and illustrating the connection of a probe to a printed circuit board in the reinforcement and a stop. Figure 14 is a section taken in the plane including line 14-14 of Figure 5, showing the printed wiring board in faded lines and illustrating an exploding power connector plug from a plug receptacle of the reinforcement. Figure 15 is a fragmentary, enlarged view of the engine illustrating a spring connection of the stator / rotor subassembly. Figure 16 is a block diagram of the individual phase motor controlled by microprocessor according to the invention. Figure 17 is a schematic diagram of the power supply of the motor of Figure 16 according to the invention. Alternatively, the power supply circuit may be modified by a DC input or by a non-double AC input. Figure 18 is a schematic diagram of the low voltage reset for the microprocessor of the motor of Figure 16 according to the invention. Figure 19 is a schematic diagram of the strobe for the motor sensor of Figure 16 according to the invention. Figure 20 is a schematic diagram of the microprocessor of the motor of Figure 16 according to the invention. Figure 21 is a schematic diagram of the sensor of the motor may of Figure 16 according to the invention. Figure 22 is a schematic diagram of the H-shaped bridge arrangement of switches for switching the stator of Figure 16 according to the invention. Figure 23 is a flow chart illustrating the operation of the microprocessor of the engine of the invention in a mode in which the motor is switched at a constant air flow rate at a speed and torque, which are defined by tables that exclude resonant points. Figure 24 is a flow chart illustrating the operation of the microprocessor of the engine of the invention in a run mode (after start) wherein the safety operation area of the engine is maintained, without current perception, having a minimum of time out for each power switch, the minimum of time out depending on the speed of the bull. Figure 25 is a diagram of time measurement illustrating the start or start mode, which provides safe operation area (SOA) control based on speed.

Figure 26 is a flow diagram of a preferred speed of the implementation of the time measurement diagram of the Figure 25, illustrating the start or start mode, which provides a safe operation area (SOA) control based on speed. Figure 27 is a timing diagram illustrating the driving mode that provides safe operation area control (SOA) based on speed. Figure 28 is a flow diagram illustrating the operation of the microprocessor of the engine of the invention in a run mode started after a pre-set number of switches in the start mode, where in the run mode, the microprocessor switches the Switches during N commutations to a period of constant switching, and wherein the switching period set every N commutations as a function of the speed, torque or constant air flow rate of the rotor. Corresponding reference characters indicate corresponding parts through the drawings.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Referring now to the drawings, and in particular to Figures 1 and 3, an electric motor 20 constructed in accordance with the principles of the present invention includes a stator 22, a rotor 24 and a housing 26 (the reference numbers designating their topics, in general). In the illustrated embodiment, the motor 10 is of the type wherein the rotor magnet is on the outside of the stator, and is shown in the form of a fan. Accordingly, the rotor 24 includes a hub 28 having fan blades 30 integrally formed therewith and projecting radially from the hub. The hub 28 and the fan blades 30 are formed as a piece of a polymeric material. The hub is open at one end and defines a cavity in which a rotor arrow 32 is mounted on the hub axis (Figure 3). The arrow 32 is attached to the hub 28 through an insert 34, which is molded to the hub, together with the end of the arrow when the hub and fan blades 30 are formed. A rotor magnet 35 that emerges from the rotor in Figure 1 includes a magnetic material and an iron backing. For simplicity, the rotor magnet 35 is shown as a unitary material in the drawings. The iron backrest is also molded into the cavity of the hub at the time the hub is formed. The stator 22, which will be described in greater detail below, is substantially encapsulated in a thermoplastic material. The encapsulation material also forms limbs 36 projecting axially from the stator 22. The limbs 36, each having a retainer 38 formed at the distal end of the limb. A printed circuit board generally indicated at 40 is received between the ends 36 in the assembled motor 10, and includes components 42, at least one of which is programmable, mounted on the board. A finger 44 projecting from the board 40 mounts a may device 46, which is received within the encapsulation when the circuit board is disposed between the ends 36 of the stator 22. In the assembled motor 10, the device may 46 is very close to the rotor magnet 35 for use in detecting the position of the rotor to control the operation of the motor. The stator 22 also includes a central locator member generally indicated at 48, and a bearing 50 around which the locator member is molded. The bearing 50 receives the rotor shaft 32 through the stator 22 to mount the rotor 24 on the stator to form a subassembly. The rotor 24 is maintained on the stator 22 through an E-shaped fastener 52 attached to the free end of the rotor after it is inserted through the stator. The housing 26 includes a cup 54 joined by three spokes 56 to an annular ring 58. The spokes 56 and the annular ring 58 generally define a reinforcement around the fan blades 30 when the motor 10 is assembled. The cup 54, rays 56 and ring ring 58 are formed as a piece from a polymeric material in the illustrated embodiment. The cup 58 is substantially closed on the left end (as shown in Figures 1 and 3), but open at the right end, so that the cup can receive a portion of the stator / rotor subassembly. Ring ring 58 has openings 60 for receiving fasteners through the ring to mount the motor at a desired location, such as in a refrigerated box (not shown). The interior of the cup 54 is formed with guide channels 62 (Figure 5) which receive respective ends 36. A shoulder 64 is formed in each guide channel 62 near the closed end of the cup 54, which engages the retainer 38 on an extremity to connect the limb to the cup (see Figures 3 and 16). The diameter of the cup 54 tapers from the opening to the closed end of the cup, so that the limbs 36 are elastically flexed radially inward from their relaxed positions in the assembled motor 10 to hold the detents 38 on the shoulders. 64. Small openings 66 in the closed end of the cup 54 (Figure 5) allow a tool (not shown) to be inserted into the cup to force the limbs 36 out of the shoulders 64 with a lever to release the connection of the sub-assembly stator / rotor cup. In this way, it is possible to disassemble the engine 10 for non-destructive repair or reconfiguration (for example, such as replacing the printed circuit board 40). The motor can be reassembled simply by re-inserting the ends 36 into the cup 54 until they snap into the connection. An application for which the motor 10 of the particular embodiment illustrated is particularly adapted, is like an evaporation fan in a refrigerated box. In this environment, the engine will be exposed to water. For example, the box can be cleaned by spraying water in the box. The water tends to be sprayed on the engine 10 from above and to the right of the engine in the orientation shown in Figure 3, and potentially can enter the engine, whenever there is an opening or joint in the engine construction. The encapsulation of the stator 22 provides protection, but it is desirable to limit the amount of water entering the motor. A possible entry site is at the junction of the hub 28 of the rotor and the stator 22. An enlarged fragmentary view of this joint is shown in Figure 12. The thermoplastic material encapsulating the stator is formed in this joint to create a path tortuous 68. In addition, a skirt 70 is formed, which extends radially outwardly from the stator. An outer edge 72 of the skirt 70 is bevelled, so that the water directed from the right is deflected from the joint. The openings 66, which allow the connection of the stator / rotor subassembly to be released, are potentially susceptible to water entering the cup, where it can interfere with the operation of the circuit board. The printed circuit board 40, including the components 42, is encapsulated to protect it from moisture. However, it remains undesirable that water substantially enters the cup. Accordingly, the openings 66 are configured to inhibit water ingress. Referring now to Figure 15, a greatly enlarged view of one of the openings 66 shows a radially outer edge 66a and radially inner edge 66b. These edges lie in a plane P1, which has an angle to a plane P2 generally parallel to the longitudinal axis of the rotor arrow of at least about 45 °. It is believed that water is sprayed onto the engine at an angle no greater than 45 °. In this way, it can be seen that the water does not have a direct path to enter the opening 66 when it travels in a path marking an angle of 45 ° or less and will continue to hit the side of the cup 54, or it will pass over the opening, but it will not enter the opening.

The cup 54 of the housing 26 is also constructed to inhibit engine failures, which may be caused by the formation of ice within the cup when the engine 10 is used in a refrigerated environment. More particularly, the printed circuit board 40 has energy contacts 74 mounted on and projecting outwardly from the circuit board (Figure 4). These contacts are aligned with an inner end of a plug receptacle 76, which is formed in the Cup 54. Referring to Figure 14, the receptacle 76 receives a plug 78 connected to a source of electrical energy away from the motor. The external controls (not shown) are also connected to printed circuit boards 40 through the plug 78. the receptacle 76 and the plug 78 have corresponding rectangular cross sections, so that when the plug is inserted, it substantially closes the receptacle Plug. When the plug 78 is fully inserted into the plug receptacle 76, the power contacts 74 on the printed circuit board 40 are received in the plug, but only partially. The plug receptacle 76 is formed with tongues 80 (near its inner end), which couple the plug 78 and limit the depth of insertion of the plug into the receptacle. As a result, the plug 78 is separated from the printed circuit board 40, even though it is fully inserted into the plug receptacle 76. In the preferred embodiment, the spacing is approximately 0.508 cm. However, it is believed that a gap of approximately 0.127 cm could lock up satisfactorily. Despite the partial reception of the energy contacts 74 in the socket 78, the electrical connection is made. The exposed portions of the energy contacts 74, which are made of metal, tend to be subject to ice formation when the motor 10 is used in certain cooling environments. However, since the plug 78 and the circuit board 40 are separated, the icing does not develop pressure between the plug and the circuit board, which could push the plug away from the circuit board, causing electrical disconnection. The ice can and will continue to form on the exposed energy contacts 74, but this will not cause disconnection, or damage to the printed circuit board 40 or to the plug 78. As shown in Figure 13, the printed circuit board 40 also has a separate group of contacts 82 used to program the motor 10. These contacts 82 are aligned with a tubular port 84 formed in the cup 54, which is normally closed by a stop 86 removably received in the port. When the stop 86 is removed, the port may receive a probe 88 together with the contacts 82 on the circuit board 40. The probe 88 is connected to a microprocessor or the like (not shown) to program or, Importantly, return to Schedule the operation of the engine after it has been fully assembled. For example, the engine speed can be changed, or the delay, before the start, can be changed. Another aspect in the refrigeration context is that the motor can be reprogrammed to operate at a different input, such as when a demand defroster is used. The presence of the port 84 and the removable stop 86 allow the motor to be reprogrammed long after the final assembly of the motor and the installation of the motor in a given application. Port 84 is closed, so that the probe can be inserted only in one direction towards the port. As shown in Figure 5, the lock is manifested as a trough 90 on one side of port 84. The probe has a corresponding flange, which is received in the trough when the probe is oriented in the proper manner relative to the trough. trough. In this way, it is not possible to incorrectly connect the probe 88 to the programming contacts. If the probe 88 is not properly oriented, this will not be received at port 84. As shown in Figure 2, the stator includes a stator core (or coil), generally indicated at 92, made of a polymeric material and a winding 94 wound around the core. The wires of the winding terminate in a terminal cavity 96 formed as a piece with the stator core 92 by terminal pins 98 received in the end cavity. The terminal pins 98 are joined in a suitable manner, such as by welding to the printed circuit board 40. However, it should be understood that other forms may be used to make the electrical connection without departing from the scope of the present invention. It can be seen that a plug-type connection (not shown) can be used so that welding is not necessary. The ferromagnetic material for conducting the magnetic flux in the stator 22 is provided by eight distinct pieces of pole, generally indicated at 100. Each pole piece has a generally U-shaped and includes a radially internal extremity 100a, a radially external extremity 100b and a cross piece of connection 100c. The pole pieces 100 each are preferably formed by stamping relatively thin U-shaped laminations from a steel strip and stacking the laminations together to form the pole piece 100. The laminations are secured together in a suitable manner, such as by welding or mechanical locking. One form of lamination (having a long radially outer end) forms the middle portion of the pole piece 100 and the other form of the lamination forms the side portions. It will be noted that a pole piece (designated 100 'in Figure 2) does not have a side portion. This is done intentionally to leave a space for insertion of the May 46 device, as described below. The pole pieces 100 are mounted on respective ends of the stator core 22, so that the radially internal end 100a of each pole piece is received in a central opening 102 of the stator core and the radially external end 100b extends axially along from the outer part of the stator core through a portion of the winding. The middle portion of the radially outwardly facing side of the radially outer end 100b, which is closer to the rotor magnet 35 in assembled motor, is formed with a notch 100d. Magnetically, the notch 100d facilitates positive location of the rotor magnet 35 relative to the pole pieces 100 when the motor is stopped. The pole pieces can also be molded from a magnetic material without departing from the scope of the present invention. In certain lower energy applications, there may be a single pole piece stamped from metal (not shown), but having multiple ends (for example 4) defining the flexed pole piece to extend axially through the winding. The pole pieces 100 are maintained and positioned by the stator core 92 and a central locator member, generally indicated at 104. The radially internal ends 100a of the pole pieces are positioned between the central locator member 104 and the inner diameter of the core. stator 92 in the central opening 102 of the stator core. The middle portions of the internal limbs 100a are formed from the same laminations, which form the middle portions of the outer ends 100b, and are wider than the lateral portions of the internal extremities. The radially inner edge of the middle portion of each inner end of pole piece 100a is received in a respective seat 104a formed in locator member 104 to accept the middle portion of the pole piece. The seats 104a are arranged to position the pole pieces 100 asymmetrically around the locator member 104. No plane passing through the longitudinal axis of the locator member 104 and crossing the seat 104a perpendicularly crosses the seat, or the piece of pole 100 located by the seat. As a result, the gap between the radially outer ends 100b and the permanent magnet 35 of the rotor 24 is asymmetric to facilitate the ignition of the engine. The radially outer edge of the inner end 100a engages ribs 106 on the inner diameter of the central stator core opening 102. The configuration of the ribs 106 can best be seen in Figures 9-11. A pair of ribs (106a, 106b, etc.) is provided for each pole piece 100. The difference angulation of the ribs 106 evident in Figures 9 and 10 reflects the angular deviation of the pole pieces 100. The pieces of pole and central locator member 104 have been shown in faded lines in Figure 9 to illustrate how each pair is associated with a particular pole piece on one end of the stator core. One of the ribs 106d 'is particularly constructed for locating the unbalanced pole piece 100' and can be coupled with the side of the inner end 100a 'instead of its radially outer edge. Another of the ribs 106d associated with the unbalanced pole piece has a smaller radial thickness, since it couples the radially outer edge of the wider middle portion of the inner end 100a '. The central locating member 104 establishes the radial position of each pole piece 100. As discussed below, some of the radial thickness initiated in the ribs 106 may be cut by shearing stress by the inner end 100a after assembly to adapt tolerances in the stator core 92, pole piece 100 and central locator member 104. The radially inner edge of each outer end 100b is positioned in a notch 108 formed on the periphery of stator core 92. Referring now to FIGS. 8, the central locator member 104 has opposite end sections, which substantially have the same shape, but are angularly offset by 45 ° about the longitudinal axis of the central locator member (see particularly Figure 7). The deflection provides the corresponding offset for each of the four pole pieces 100 on each end of the stator core 92 to be fixed on the stator core without interfering with one of the pole pieces on the opposite end. It is evident that the angular deviation is determined by the number of pole pieces 100 (ie, 360 ° divided by the number of pole pieces), and could be different if a different number of pole pieces were employed. The shape of the central locator member 104 could be correspondingly changed to accommodate a different number of pole pieces 100, as shown in Figure 8, the central locator member 104 being molded around a metal rotor shaft bearing 110, which is self-lubricating for the life of the motor 10. The stator core 92, the winding 94, the pole pieces 100, the locating member 104 and the bearing 110 are all encapsulated in a thermoplastic material to form the stator 22. The ends of the rotor shaft bearing 110 are not covered with the encapsulation material, so that the arrow of the rotor 32 can be received through the bearing to mount the rotor 24 on the stator 22 (see Figure 3).

Assembly Method Having described the construction of the electric motor 10, a preferred method for assembly will now be described. Initially, parts of the engine component will be made. The precise order of construction of these parts is not critical, and it will be understood that some or all of the parts can be made at a distant site, and embarked to the final assembly site. The rotor 24 is formed by placing the magnet 35 and the rotor shaft 32, having the insert 34 at one end, in a mold. The hub 28 and the fan blades 30 are molded around the magnet 35 and the rotor shaft 32, so that they are held securely on the hub. The housing 26 is also formed by molding the cup 54, spokes 56 and ring ring 58 as a single piece. The cup 54 is formed internally with the ribs 112 (Figure 5), which are used to secure the printed circuit board 40, as will be described. The printed circuit board 40 is formed in a conventional manner through the connection of the components 42 to the board. In the preferred embodiment, the programming contacts 82 and the energy contacts 74 are thrown to the circuit board 40, instead of being assembled by welding (Figure 4). The may device 46 is mounted on the finger 44 extending from the board and electrically connected to the components 42 on the board. The stator includes several component parts, which are formed before a stator assembly. The central locator member 104 is formed by molding around the bearing 110, which is made of bronze. The ends of the bearing 110 exit from the locating member 104. The bearing 110 is then impregnated with sufficient lubricant to last the entire life of the motor 10. The stator core 92 (or coil) is molded and wound with magnet wire and finished for forming the winding 94 on the stator core. The pole pieces 100 are formed by stamping multiple, thin, generally U-shaped laminations from a steel strip. The laminations are preferably made in two different ways, as described above. The laminations are stacked together and welded together to form each piece of U-shaped pole 100, the laminations having the longest outer end and the widest inner end forming middle portions of the pole pieces. However, a piece of pole 100 'is formed without a side portion, so that a gap will be left for the Hall device 46. The stator component parts 22 are assembled in a press fitting (not shown). The four pole pieces 100, which will be mounted on one end of the stator core 92, are first placed in the fixture in groups of positions by the fixture, which are 90 ° apart around what will be the axis of rotation of the fixture. rotor arrow 32. The pole pieces 100 are positioned so that they open upwards. The central locating member 104 and the bearing 110 are positioned in the fitting in a required orientation and extend through the central opening 102 of the stator core 92. The radially internal edges of the middle portions of the internal ends 100a of the parts of pole are received in respective seats 104a formed on one end of central locating member 104. The wound stator core 96 is fixed in the fitting generally on top of the pole pieces previously placed in the fitting. The other four pole pieces 100 are placed in the fitting above the stator core 92, but at the same angle they will assume relative to the stator core when the assembly is complete. The pole pieces 100 above the stator core 92 open downwards and are positioned at locations, which are 45 ° offset from the positions of the pole pieces at the bottom of the fitting. He Press fit is closed and activated to push the pole pieces 100 onto the stator core 92. The radially internal edges of the inner ends 100a of the pole pieces 100 engage their respective seats 104a of the central locator member. The seat 104a seats the radial position of the pole piece 100 that it engages. The internal ends 100a of the pole pieces 100 enter the central opening 102 of the stator core 92 and engage the ribs 106 on the stator core projecting towards the central opening. Variations in the radial dimensions of design specifications in the central locator member 104, the pole pieces 100 and the stator core 92 caused by manufacturing tolerances, are adapted by the internal ends 100a by cutting some of the material from the ribs 106 coupled by the pole pieces. The shearing action occurs as the pole pieces 100 are passed over the stator core 92. In this way, the tolerances of the stator core 92 are completely removed from the radial positioning of the pole pieces. The radial location of the pole pieces 100 must be closely controlled in order to keep the air gap between the pole pieces and the rotor magnet 35, as small as possible, without mechanical interference of the stator 22 and the rotor 24. The stator core 92 assembled, the pole pieces 100, the central locator member 104 and the bearing 110 are placed in a mold and substantially encapsulated in a suitable fire-resistant thermoplastic material. In some applications, the mold material may not be fire resistant. The ends of the bearing 110 are covered in the molding process and remain free of the encapsulation material. The terminal pins 98 for making the electrical connection with the winder 94 are also not completely covered by the encapsulation material (see Figure 4). The skirt 70 and the ends 36 are formed of the same material that encapsulates the rest of the stator. The limbs 36 are preferably relatively long, constituting approximately one third of the length of the encapsulated, finished stator. Its length allows the limbs 36 to become thicker for a more robust construction, while allowing the elastic flexing necessary for the jump connection to the housing 26. In addition to the limbs 36 and the skirt 70, two pins 114 are formed, which project axially in the same direction as the extremities and require that the stator 22 be in a particular angular orientation relative to the housing 26 when the connection is made. Even more, supports of the printed circuit board are formed. Two of these are in the form of block 116, from one of which terminal pins 98 are projected, and the other two are posts 118 (one of which is shown). The encapsulated stator 22 is then assembled with the rotor 24 to form the stator / rotor subassembly. A thrust washer 120 (Figure 3) is positioned on the rotor shaft 32 and slides toward the fixed end of the rotor shaft in the hub 28. The thrust washer 120 has a rubber-like material on one side, capable of absorbing vibrations, and a low friction material on the other side to facilitate sliding engagement with the stator 22. The low friction material side of the washer 120 faces axially outward toward the open end of the hub 28. stator 22 is then dropped into the hub 28, with the rotor shaft 32 being received through the bearing 1110 in the center of the stator. One end of the bearing 110 engages the low friction side of the thrust washer 120, so that the hub 28 can rotate freely with respect to the bearing. Another thrust washer 122 is placed on the free end of the bearing 110 and the E-shaped fastener 52 is configured on the end of the rotor shaft 32, so that the arrow can not pass back through the bearing. In this way, the rotor 24 is securely mounted on the stator 22. The printed circuit board 40 is secured to the stator / rotor subassembly. The assembly of the printed circuit board 40 is illustrated in Figure 4, except that the rotor 24 has been removed to have a better illustration. The printed circuit board 40 is pushed between the three ends of the stator 22. The finger 44 of the circuit board 40 is received in an opening 124 formed in the encapsulation, so that the device 46 on the end of the finger is placed within the encapsulation immediately after the piece of unbalanced pole 100 ', which was made without a lateral portion, so that the space can be provided for the device of may. The side of the circuit board 40 closest to the stator 22 couples the blocks 116 and posts 118, which keep the circuit board at a predetermined separate position from the stator. The terminal pins 98 projecting from the stator 22 are received through two openings 126 in the circuit board 40. The terminal pins 98 are electrically connected to the circuit board of the components 42 in a suitable manner, such as through of welding. The connection of the terminal pins 98 to the board 40 is the only fixed connection of the printed circuit board to the stator 22. The stator / rotor subassembly and the printed circuit board 40 are then connected to the housing 26 to complete the motor assembly. The limbs 36 are aligned with the respective channels 62 in the cup 54 and the pins 114 are aligned with the depressions 128 formed in the cup (see Figures 5 and 14). The limbs 36 will be received in the cup 54 only in one orientation due to the presence of the pins 114. The stator / rotor subassembly is pushed towards the cup 54. The free ends of the ends 36 are bevelled on their outer ends to facilitate the entrance of the limbs into the cup 54. The cup tapers slightly towards its closed end and the limbs 36 are flexed radially inward from their relaxed configurations as they enter the cup and as they are pushed further towards it. When the retainer 38 at the end of each limb releases the shoulder 64 at the inner end of the channel 62, the extremity 36 snaps radially outwardly, so that the retainer engages the shoulder. The end 36 continues to be bent from its relaxed position so that it is deflected radially outward to maintain the retainer 38 on the shoulder 64. The engagement of the retainer 38 with the shoulder 64 prevents the stator / rotor subassembly and the printed circuit board 40 are removed from the cup 54. the motor 10 is now fully assembled if the use of any fastener, through a jump construction. The printed board circuit 40 is secured in place through an interference fit with the ribs 112 and the cup 54. As the stator / rotor assembly advances towards the cup 54, the peripheral edges of the circuit board 40 the ribs 112 are engaged. The ribs are harder than the printed circuit board material, so that the printed circuit board is partially deformed by the ribs 112 to create the interference fit. In this way, the printed circuit board 40 is secured in place without the use of any fasteners. The angular orientation of the printed circuit board 40 is fixed by its connection to the terminal pins 98 from the stator 22. The programming contacts 82 are thus aligned with the port 84 and the energy contacts 74 are aligned with the receptacle plug 76 in the cup 54. It can also be seen that the printed circuit board 40 can be secured to the stator 22 without any interference fit with the cup 54. For example, a post (not shown) formed on the stator 22 can be extended through the circuit board and receive a push notch on it against the circuit board to fix the circuit board on the stator. In the preferred embodiment, the engine 10 has not been programmed or tested before the final assembly of the engine. After assembly, a coupled connector (not shown, but essentially a probe 88 and an energy plug 78) is connected to the printed circuit board 44 through the port and plug receptacle 76. The motor is then programmed, such as setting the speed and departure delay, and tested. If the circuit board 40 is defective, it is possible to disassemble the engine in a non-destructive way and replace the circuit board without discarding other parts of the engine. This can be done by inserting a tool (not shown) into the openings 66 in the closed end of the cup 54 and forcing the retainer 38 out of the shoulders 64 with a lever. If the engine passes the quality safety tests, the stop 86 is placed on port 84 and the engine ready for shipment. It is possible with the engine of the present invention to reprogram the engine 10 after it has been shipped from the engine assembly site. The end user, such as a refrigerated case manufacturer, can remove retainer 86 from port 84 and connect probe 88 to programming contacts 82 through the port. The motor can be re-programmed as necessary to adapt changes made by the end user in the operating specifications for the motor. The motor 10 can be installed, such as in a refrigerated box, by inserting fasteners (not shown) through the openings 60 in the annular ring 58 and in the box. In this way, the housing 26 is able to support the entire motor through the connection of the annular ring 58 to a support structure. The motor is connected to a power source by connecting the plug 78 in the plug receptacle 76 (Figure 14). Locks 130 (only one is shown) are received on the sides of the plug 78 in slots on the respective sides of a tab 132 to close or lock the plug in the plug receptacle 76. Prior to the coupling of the printed circuit board 40, the plug 78 engages the locator tabs 80 in the plug receptacle 76, so that in its fully inserted position, the plug is separated from the printed circuit board. As a result, the energy contacts 74 are inserted far enough into the socket 78 to make the electrical connection, but not fully received in the socket. Therefore, although ice may form on the energy contacts 74 in the refrigerated box environment, it will not develop between the plug 78 and the circuit board 40 causing disconnection and / or damage. Figure 16 is a block diagram of the individual phase motor 500 controlled by microprocessor according to the invention. The motor 500 is driven by an AC power source 501. The motor 500 includes a stator 502 having a single phase winding. The direct current energy from the source 501 is supplied to an energy switching circuit through a power supply circuit 503. The power switching circuit can be any circuit for switching the stator 502, such as a bridge with H form 504 having power switches to selectively connect the power source of 501 to the individual phase winding of the stator 502. A permanent magnet rotor 506 is in a magnetic coupling relationship with the stator and is rotated through the switching of the winding and the magnetic field created by it. Preferably, the motor is an upside down motor, wherein the stator is inside the rotor and the outer rotor rotates around the inner stator. However, it is also contemplated that the rotor may be located within and internally to an internal stator. A position sensor such as a hall sensor, 508 is placed on the stator 502 to detect the rotor position 506 relative to the winding and to provide a position signal through the line 510 indicating the detected position of the rotor 506. The reference character 502 generally refers to a control circuit including a microprocessor 514 responsive to and receiving the position signal through line 510. the microprocessor 514 is connected to the H-shaped bridge 504 to selectively switch its switches energy for switching the individual phase winding of stator 502 as a function of the position signal. The voltage VDD to the microprocessor 514 is provided through the line 516 from the power supply circuit 503.

A low voltage reset circuit 518 checks the voltage VDD on line 516 and applies it to microprocessor 514. Reset circuit 518 selectively resets microprocessor 514 when the voltage VDD applied to the microprocessor through line 516 goes from a threshold default low to above the predetermined threshold. The threshold is generally the minimum voltage required by the microprocessor 514 for it to operate. Therefore, the purpose of the reset circuit 518 is to maintain the operation and reset operation of the microprocessor in the event that the voltage VDD supplied through line 516 falls below the preset minimum required by the microprocessor 514 so that this operates. Optionally, to save energy, the hall sensor 508 can be intermittently operated by a hall strobe 520 controlled by the microprocessor 514 for the pulse width and thus modulate the energy applied to the hall sensor. The microprocessor 514 has a control input 522 for receiving a signal that affects the motor of the control 500. For example, the signal may be a speed selection signal in the case that the microprocessor is programmed to operate the rotor, so that The stator is switched to two or more discrete speeds. Alternatively, the motor can be controlled at continuously variable torques or torques according to the temperature. For example, instead of or in addition to the hall sensor, 508, an optional temperature sensor 524 can be provided to sense the ambient air temperature around the engine. This embodiment is particularly useful when the rotor 506 drives a fan that moves the air through a condenser to remove the heat generated by the condenser or which moves the air through an evaporator for cooling, as illustrated in Figures 1 -fifteen. In one embodiment, the processor interval clock corresponds to a temperature of air moving around the engine and to providing a temperature signal indicating the detected temperature. For condenser applications where the fan is blowing air into the condenser, the temperature represents the ambient temperature and the velocity (air flow) is adjusted to provide the minimum necessary air flow at the measured temperature to optimize the transfer process. hot. When the fan is pulling air over the condenser, the temperature represents the ambient temperature plus the change in temperature (? T) added by the heat removed from the condenser by the air stream. In this case, the motor speed is increased in response to the higher combined temperature (the speed is increased by increasing the torque of the motor, i.e. by reducing the time out of the PDOFFTIM power device, see Figure 26). In addition, the motor speed can be set for different temperature bands to give a different air flow which can be different constant air flows in a given static fan pressure condition. Also, in a capacitor application, the torque applied to apply the motor at the desired speed represents the static load on the motor. The highest static charges can be caused by the installation in a restricted environment, that is, in a refrigerated installed as in a building, or as the air flow of the condenser that is restricted due to the development of dust or waste. Both conditions can guarantee an increased flow / air speed. Similarly, in evaporator applications, high static pressure may indicate evaporator freezing or increased packing density for items that are cooled. In one of the commercial refrigeration applications, the evaporator fan draws the air from the air curtain and from the exhaust air cooling the food. This fan exhaust is blown through the evaporator. The intake air temperature represents air curtains and the air temperature of the food outlet. The fan speed can be adjusted appropriately to maintain the desired temperature. Alternatively, the microprocessor 514 can switch the switches at a variable speed to maintain a substantially constant air flow rate of air that is removed by the fan connected to the rotor 506. In this case, the microprocessor 514 provides an alarm signal by activating the alarm 528 when the motor speed is greater than a desired speed corresponding to the constant air flow rate at which the motor is operating. As with the desired torque, the desired speed can be determined by the microprocessor as a function of the initial static load of the motor and changes in the static load over time. Figure 23 illustrates a preferred embodiment of the invention, wherein the microprocessor 514 is programmed according to the flow diagram thereof. In particular, the flow diagram of Figure 23 illustrates a mode in which the motor is switched to a constant air flow rate corresponding to a speed and torque, which are defined by the tables excluding resonant points. For example, when the rotor is activating a fan to move air over a condenser, the motor will have certain speeds at which a resonance will occur, causing increased vibration and / or increased noise. The speeds at which said vibration and / or noise occur are usually the same or similar and can be predicted, particularly when the motor and its associated fan are manufactured for tight tolerances. In this way, vibration and noise can be minimized by programming the microprocessor to avoid operation at certain speeds or within certain speed scales where vibration or noise occurs. As illustrated in Figure 23, the microprocessor 514 can operate in the following manner. After start-up, the microprocessor sets the target variable I to correspond to an initial starting velocity pointer defining a constant air flow rate, in step 550. For example, 1 = 0. Next, the microprocessor proceeds to step 552 and selects a speed fixation point (SSP) of a table that correlates each of the variable levels of 0 ana a corresponding speed setting point (SSP), to a corresponding timeout energy device (PDOFFTIM = Prn N) for the minimum energy and a corresponding timeout device of energy PDOFFTIM for maximum energy. It is noted that as PDOFFTIM increases, the motor energy decreases since the controlled energy switches are out of time for longer periods during each switching interval. Therefore, the flow chart of Figure 23 is specific to this aspect. Other experts in the art will recognize other equivalent techniques for controlling the power of the engine. After a delay in step 554 to allow the motor to stabilize, the microprocessor 514 selects a PDOFFTIM for a minimum power level (Pmin) of the table that provides the current control by correlating a minimum energy level to the level selected from variable I. In step 558, the microprocessor selects PDOFFTIM for a maximum power level (Pma?) of the table that provides the current control by correlating a maximum energy level with the selected variable level I. In step 560, the microprocessor compares the actual PDOFFTIM representing the actual power level with the PDOFFTIM (Pm? N) for I. If the actual PDOFFTIM is greater than the minimum PDOFFTIM (PDOFFTIM >; Pm? N), the microprocessor proceeds to step 562 and compares the level of variable I with a maximum value n. If I is greater than or equal to n, the microprocessor proceeds to step 564 to set I equal to n. Otherwise, I must be less than the maximum value for I, so that the microprocessor 514 proceeds to step 566 to increase I by one step. If, in step 560, the microprocessor 514 determines that actual PDOFFTIM is less than or equal to the minimum PDOFFTIM (PDOFFTIM <_ Pmin). the microprocessor proceeds to step 568 and compares the current PDOFFTIM representing the current energy level with the PDOFFTIM (Pmax) for I. If the current PDOFFTIM is less than the maximum PDOFFTIM (PDOFFTIM <Pmax), the microprocessor proceeds to step 570 and compares the level of variable I with a minimum value of 0. If I is less than or equal to 0, the microprocessor proceeds to step 572 to set equal to 0. Otherwise, I must be greater than the minimum value for I, so that the microprocessor 514 proceeds to step 574 to decrease I by one step. If current PDOFFTIM is less than or equal to the minimum and is greater than or equal to the maximum, so that the response for both steps 560 and 568 is no, the engine operates at the speed and energy necessary to provide the desired airflow of so that the microprocessor returns to step 552 to maintain its operation. Alternatively, the microprocessor 514 can be programmed with an algorithm that defines the variable speed at which the switches are switched. This variable speed may vary continuously between a pre-established scale of at least a minimum speed Sm, n and not greater than a maximum speed Sma, except that a predefined scale of speeds S1 +/- S2 is excluded from the preset scale. As a result, the speeds between SI - S2 and S1, the microprocessor operates the motor at S1 - S2 and for speeds between S1 and S1 + S2, the microprocessor operates the motor at speeds S1 + S2. Figure 22 is a schematic diagram of the H-shaped bridge 504, which constitutes the power switching circuit having power switches according to the invention, although other configurations can be used, such as two windings that are individually terminated or the H-shaped bridge configuration of U.S. Patent 5,859,519, incorporated herein by reference. The input voltage is provided through a lane 600 to the input switches Q1 and Q2. An output switch Q3 completes a circuit by selectively connecting the switch Q2 and the stator 502 to a ground rail 602. One output switch Q4 completes another circuit by selectively connecting the switch Q1 and the stator 502 to the ground rail 602. The switch Q3 output is controlled through a Q5 switch, which receives a control signal through port BQ5. The output switch Q4 is controlled through a switch Q8, which receives a control signal through the BQ8 port. When the switch Q3 is closed, the line 604 pulls the gate of Q1 down to open the switch Q1, so that the switch Q1 is always open when the switch Q3 is closed. Similarly, line 606 ensures that switch Q2 is open when switch Q4 is closed. The individual phase winding of stator 502 has a first terminal F and a second terminal S. As a result, switch Q1 constitutes a first input switch connected between terminal S and the power supply provided through rail 600. The switch Q3 constitutes a first output switch connected between the S terminal and the ground rail 602. The switch Q2 constitutes a second input switch connected between the F terminal and the power supply provided through the rail 600. The switch Q4 constitutes a second output switch connected between terminal F and ground rail 602. As a result, the microprocessor controls the first input switch Q1 and the second input switch Q2 and the first output switch Q3 and the second output switch Q4, so that the current between the movement is provided during the first 90 ° of the period of switching illustrated in Figure 27. The first 90 ° is important due to noise and efficiency ratios and applies this to the topology of the power device (that is, either Q1 or Q2 is always "on" when Q3 is already or Q4 is off, respectively). PDOFFTIM is the term used in software energy control algorithms. When the first output switch Q3 is open, the first input switch Q1 is closed. Similarly, the second input switch Q2 is connected to and is sensitive to the second output switch Q4, so that when the second output switch Q4 is closed, the second input switch Q2 is open. Also, when the second output switch Q4 is open, the second input switch Q2 is closed. This is illustrated in Figure 27, where it is shown that the state of Q1 is opposite to the state of Q3, and the state of Q2 is opposite to the state of Q4 at any time. Figure 26 is a flow diagram of time measurement illustrating the start or run mode with a maximum current determined by the PDOFFTIM setting against the motor speed. In this mode, the energy devices are pulse-width modulated software in a continuous mode to get the engine started. The present boot algorithm remains in start or start mode for eight switches, and then goes to boot mode. A similar algorithm can approximate a constant acceleration by selecting the correct fixes for PDOFFTIM against speed. In step 650, the HALLIN value is a constant that defines the start value of the Hall device reading. When the reading of the current Hall device (HALLOLD) changes in step 652, HALLIN is set to be equal to HALLOLD in step 654, and PDOFFTIM is changed in step 656 depending on RPMs. Figure 25 illustrates the outputs of the microprocessor (BQ5 and BQ8) that control the motor when the output of the strobe hall effect (HS3) changes the state. In this example, BQ5 is a pulse width modulated, while HS3 is 0. When HS3 (strobe) changes to 1, there is a finite period of time (LATENCY) for the microprocessor to recognize the magnetic change after BQ5 is in. the shutdown state, so that BQ8 starts to modulate by pulse width (during PWMTIM). Figure 24 illustrates another alternative aspect of the invention, wherein the microprocessor operates within an operation mode safety operation area without the need for current perception. In particular, according to Figure 24, the microprocessor 514 controls the input switches Q1-Q4, so that each input switch is open or closed for a minimum period of time (PDOFFTIM) during each period of width modulation. pulse so that protection is provided over temperature without current perception. Specifically, the minimum period can be a function of the rotor speed, whereby a temperature protection without current perception is provided limiting the total current with time. As illustrated in Figure 24, if the speed is greater than a minimum value (ie, if A <; 165), A is set at 165 and the SOA limit is derived and not required. If the speed is less than (or equal to) a minimum value (ie, if A> .165), the routine in Figure 24 ensures that the switches are off for a minimum period of time to limit the current. "A" is a variable and is calculated through an equation that represents a minimum value of PDOFFTIM at a given speed (the velocity is a constant multiplied by 1 / TINPS, where TINPS is the period of the motor). Then PDOFFTIM is < A, PDOFFTIM is set to A, so that the motor current is maintained at a maximum desired value at the speed at which the motor is operating. As illustrated in Figure 18, the engine includes a reset circuit 512 to selectively reset the microprocessor when a voltage of the power supply transitions vdd is below the predetermined threshold to above a predetermined threshold. In particular, the switch Q6 disables the microprocessor through the MCLR / VPP port when the voltage divided between the resistors R16 and R17 falls below a predetermined threshold. The microprocessor is reactivated and reset when the voltage returns to be above the predetermined threshold, thereby causing switch Q6 to close. Figure 19 illustrates a preferred embodiment of a strobe circuit 520 for the hall sensor, 508. The microprocessor generates a modulated pulse width signal GP5, which intermittently drives the hall 508 sensor, as shown in Figure 21 by intermittently closing the switch Q7 and providing the voltage VB2 to the hall sensor 508 through the line HS1. Figure 17 is a schematic diagram of the power supply circuit 503, which supplies the Ventrada voltage to energize the individual stator phase winding through the H 504 shaped bridge and which also supplies several other voltages to control the H-shaped bridge 504 and to activate the microprocessor 514. In particular, the lower activation voltages including VB2 to provide control voltages to the switches Q1-Q4, VDD to activate the microprocessor, HS2 to activate the hall sensor 508 , and VSS, which is the reference ground of the control circuit not necessarily referenced to the input AC or DC voltage, are supplied from the input voltage Ventrada through a capacitor in line without loss C1. Figure 20 illustrates the inputs and outputs of the microprocessor 514. In particular, only a single input GP4 of the position sensor is used to provide information that controls the status of the control signal BQ5 applied to the switch Q5 to control the output switch Q3 and the input switch Q1 and which controls the state of the control signal BQ8 applied to the switch Q8 to control the output switch Q4 and the input switch Q2. The input GP2 is an optional input for selecting the motor speed or other characteristic or it can be connected to receive a temperature input comparator output when the combination with a thermistor 524 is used. Figure 28 illustrates a flow diagram of the preferred mode of a running mode, wherein the energy devices are controlled in the current, in this mode, the following operating parameters are applied: ENERGY DEVICE CONTROL THAT STARTS TO AN ENGINE (CURRENT) • At the end of each commutation, the time energy devices are out of the next time when the commutation period is calculated. OFFTIM = TINP / 2. (The switching period divided by 2 = 90 °). While it is in the start routine, it is also calculated.

• After 8 commutations (1 motor revolution) and at the output of the start routine, PWMTIM is calculated: PWMTIM = OFFTIM / 4. • At the beginning of each switching period, a counter (COUNTER 8) is set to five to allow the power devices to turn on four times during this switchover: PWMSUM = PWMTIM PDOFFSUM = PWMTIM-PDOFFTIM TIME MEASUREMENT = 0 (PDOFFTIM Used to control the amount of current in the motor and is adjusted in the control algorithm (SPEED, TORQUE, CFM, etc.). «The switching time is set to 0 at each change of strobe hall, HALLOLD is the stored hall strobe value.When the motor is running, the flow diagram of Figure 28 is executed during each switching period.In particular in step 702, the switching time is first checked to see if the motor has has been in this motor position for too long, in this case 32mS.If this is the case, a closed rotor is indicated and the program goes to the closed rotor routine in step 704. Otherwise, the program checks to see if the switching time is greater than OFFTIM in step 706; if so, the switching period is greater than 90 ° electrical and the program branches to step 708, which shuts down the lower energy devices and exits the routine in step 710. Next, the switching time is compared in step 712 for PWMSUM. If this is less than PWMSUM, the switching time is verified in step 714 to see if it is less than or equal to PDOFFSUM, where if this is true, the routine exits step 716; otherwise, the routine branches to step 708 (if step 714 is yes). For the other case, where the switching time is greater than or equal to PWMSUM, in step 718, PWMSUM and PDOFFSUM have been added PWMTIM to prepare the next pulse width modulation period and a variable A is set in the ACCOUNT 8-1. If A is equal to zero in step 720, the pulse width modulations (4 pulses) for this switching period are completed and the program branches to step 708 to shut down the lower energy devices and exit this routine . If A is not equal to zero, ACCOUNT 8 (which is a variable that defines the number of PWMs per switch) is set to A in step 722; the lowest appropriate energy device is turned on; and this routine comes out of step 716. More PWM accounts per switching period can be implemented with a faster processor. Four (4) PWMs per switching period are preferred for slower processors, while eight (8) are preferred for faster processors. The time measurement diagram for this is illustrated in Figure 27. In the closed rotor routine of step 704, or input, the lower energy devices are turned off for 1.8 seconds after which a normal start is attempted. In view of the above, it will be seen that several objects of the invention are achieved and other advantageous results are obtained. Since several changes can be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings should be interpreted only as illustrative and not in a limiting sense.

Claims (34)

1. - A method for assembling an electric motor comprising the steps of: forming a stator including a stator core and a winding placed around the stator core; form a rotor including an arrow; forming a housing adapted to support and at least partially enclose the stator and the rotor; mounting the rotor on the stator by inserting the arrow through the stator to form a stator / rotor subassembly, the rotor being mounted to rotate relative to the stator about a longitudinal axis of the rotor shaft; and connect by jump the stator / rotor subassembly to the housing.

2. A method for assembling an electric motor according to claim 1, wherein the step of forming the stator includes forming a first connector element by jumping with the stator, the step of forming the housing includes forming a second stator element. jump connector with the housing, and the step of hopping the stator / rotor subassembly with the housing comprises the step of interconnecting the first and second connector elements by jump.

3. A method for assembling an electric motor according to claim 2, wherein the step of forming a first connector element per jump comprises the step of encapsulating the stator core and the winding with a thermoplastic material and simultaneously forming limbs. from the material, each of the limbs projecting axially from the stator and having a retainer integrally formed at a free end of the limb.

4. - A method for assembling an electric motor according to claim 3, wherein the step of forming the second connector element per jump includes forming the housing to have an internal shoulder for each of the stator ends, each opening being dimensioned and formed to receive the detent at the free end of one of the respective ends for the jump connection of the ends with the housing.

5. A method for assembling an electric motor according to claim 2, wherein the step of forming the first connector element per jump comprises providing ends on the stator.

6. A method for assembling an electric motor according to claim 5, wherein the step of forming the second connector element per jump comprises forming the housing so that it has an internal shoulder for each extremity, each extremity formed with a retainer that can be coupled with the shoulder after the step of connecting by jump for the connection by jump from the extremities to the housing.

7. A method for assembling an electric motor according to claim 1, further comprising the step of installing a printed circuit board on the stator by making an electrical connection of the printed circuit board to the stator winding, the circuit board printed being free of any other fixed connection to the stator.

8. A method for assembling an electric motor according to claim 7, wherein the step of hopping the stator / rotor subassembly with the housing includes coupling the printed circuit board with the housing to form an interference fit. of the printed circuit board with the housing, the printed circuit board being free of any other connection to the housing.

9. A method for assembling an electric motor according to claim 1, wherein the step of forming the stator includes the step of radially locating a plurality of different pole pieces made of ferromagnetic material with respect to a central longitudinal axis of the Stator core from a central locator member that can be received in a central opening of the stator core, radial tolerances of the central locator member and the stator core being taken by the material of the stator core during the locating step.

10. A method for assembling an electric motor according to claim 9, wherein the step of locating the pole pieces comprises forcing the pole pieces towards the central opening in a space between the central locator member and the stator core, the pole pieces cutting the stator core material as with forced into the space between the central locator member and the stator core.

11. A method for assembling an electric motor according to claim 10, further comprising molding a bearing of the rotor shaft in the central locating member.

12. A method for assembling an electric motor according to claim 1, comprising, after the step of connecting by jump the stator / rotor subassembly to the housing, the steps of inserting a probe through a port formed in the housing, coupling the electrical contacts on a printed circuit board inside the housing with the probe, and programming the printed circuit board through the probe.

13. A method for assembling an electric motor according to claim 1, comprising, after the step of connecting by jump the stator / rotor subassembly to the housing, the steps of inserting a probe through a port formed in the housing, coupling the electrical contacts on a printed circuit board inside the housing with the probe, and performing an electrical test on the motor through the probe.

14. A method for assembling an electric motor according to claim 1, comprising, after the step of connecting by jump the stator / rotor sub-assembly to the housing, the steps of inserting a probe through a port formed in the housing, coupling electrical contacts on a printed circuit board inside the housing with the probe, programming the printed circuit board through the probe and performing an electrical test on the motor through the probe.

15. A method for assembling an electric motor according to claim 14, further comprising, after the step of programming the printed circuit board and performing an electrical test of removing the probe and closing the port with a stopper releasably connected to the accommodation.

16. An electric motor comprising: a stator that includes a stator core, a winding on the stator core and a first connector element per jump; a rotor including an arrow received in the stator core for rotation of the rotor relative to the stator about the longitudinal axis of the arrow; a housing adapted to support the stator and the rotor, the housing having a second jump connector element formed therein, the first jump connector element being coupled with the second jump connector element for connecting the stator and the rotor To the accommodation.

17. An electric motor according to claim 16, wherein the first stator jump connector element comprises a plurality of limbs projecting from the stator, each end being capable of elastic deflection and having a retainer formed at its end. .

18. An electric motor according to claim 17, wherein the second jump connector element comprises a plurality of shoulders in the housing, each shoulder engaging the retainer of one of the respective ends, with the end in an elastically position deformed for the closing coupling by jump of the extremities with the housing.

19. An electric motor according to claim 18, wherein the rotor comprises a hub and fan blades projecting radially outwardly from the hub, the hub defining a cavity opening in an axial end of the hub receiving a portion of the hub. stator therein, the rotor arrow being generally disposed in the cavity.

20. An electric motor according to claim 18, wherein the housing comprises a cup that receives a portion of the stator therein, the cup including the shoulders coupling the retainers of the ends, and the openings in the cup arranged for that the free ends of the limbs have access in the housing to release, in a non-destructive manner, the stoppers of the shoulders in the cup to disassemble the motor.

21. An electric motor according to claim 20, wherein each opening in the housing includes a radially outer edge and a radially inner edge lying in a plane that forms an angle of at least about 45 ° with the longitudinal axis of the rotor arrow, to inhibit the entry of water into the housing through the opening.

22. An electric motor according to claim 20, wherein the housing further comprises a plurality of spokes and an annular ring, the rays projecting radially from the cup to the annular ring and connecting the cup and the annular ring, the spokes defining a reinforcement around the fan blades.

23. An electric motor according to claim 22, wherein the annular ring has fastening openings therein, adapted to receive fasteners for mounting the motor on a structure.

24. An electric motor according to claim 16, wherein the stator core and the winding are substantially encapsulated in a thermoplastic encapsulating material, the first jump connector element being formed as a part from the thermoplastic material encapsulating the stator core and the winding.

25. An electric motor according to claim 24, wherein the encapsulating material is formed with a generally annular skirt, projecting radially outward from the encapsulated stator core, the skirt being in a separate relation with the rotor to define an outer stator / rotor joint, the skirt having a beveled edge to divert water away from the joint to thereby inhibit water ingress between the rotor and the stator.

26. An electric motor according to claim 16, further comprising a printed circuit board having an electrical connection to the winding and being free of another connection to the stator, the printed circuit board having an interference fit with the housing and being free from another connection to the accommodation.

27. An electric motor according to claim 26, wherein the housing has internal osti lias formed therein and coupling peripheral edges of the printed circuit board to form said interference fit with the circuit board.

28. An electric motor according to claim 16, wherein the stator further comprises a plurality of pole pieces and a central locating member, the central locating member being received in a central opening of the stator core and engaging radially internal edges. of the pole pieces to radially place the pole pieces.

29. An electric motor according to claim 28, wherein the stator core includes ribs projecting radially inward toward the central opening of the stator core and engaging the pole pieces, the pole pieces cutting the material from less one of the ribs after the assembly of the pole pieces and the central locating member with the stator core, so that one of the ribs has a reduced radial thickness.

30. An electric motor according to claim 28, further comprising a rotor shaft bearing generally disposed in the central opening of the stator core and receiving the rotor arrow therein, the central locating member being molded around the bearing.

31. An electric motor according to claim 16, further comprising a printed circuit board having programmable components adapted to control the operation of the motor, the printed circuit board being received in the housing and having electrical contacts therein, and wherein the housing has a port formed therein and generally aligned with the contacts on the printed circuit board, so that the contacts have access through the port for connection to a microprocessor.

32. An electric motor according to claim 31, further comprising a stop releasably coupled in the port to close the port. 33.- An electric motor according to claim 16, wherein the stator comprises a plurality of pole pieces mounted on the stator core, each pole piece having a generally U-shape and including an internal extremity received in an aperture. core of the stator core and an outer end extending axially of the stator core at a location outside the stator core, a face directed radially outwardly of the outer end having an aperture notch radially outward therein. 34.- An electric motor according to claim 16, further comprising a printed circuit board electrically connected to the winding and generally arranged in the housing, the printed circuit board having an energy contact mounted therein to receive power electrical for the winding, and wherein the housing is formed with a plug receptacle to receive a plug from an external power source for connection to the power contact, the power contact being received at the plug after the connection from the plug to the power contact, the housing including a plug locator to locate the plug relative to the power contact, so that the contact is only partially received in the plug after the plug is connected.