JP2008109848A - Armature unit and manufacturing method thereof, motor having armature unit, and pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an armature unit preventing poor quality in the appearance of a mold section and in the continuity of a circuit board, and to provide a method of manufacturing the armature unit, a motor having the armature unit, and a pump. <P>SOLUTION: The mold section 40 of the armature unit 10 is composed of a first mold section 41 for covering the periphery of the circuit board 30 and a second mold section 42 for covering the periphery of the first mold section 41 and an entire armature 20. The first mold section 41 is formed in a low-pressure state, thus preventing warpage and cracks in the circuit board 30 in molding. The periphery of the first mold section 41 is covered with the second mold section 42, thus allowing the circuit board 30 to prevent exposure from the outside completely, and preventing an electrical short-circuiting caused by adhering oil, water, or the like from the outside to the circuit board 30. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an armature unit in which an armature and a circuit board are integrated by molding, a method for manufacturing the armature unit, and a motor and a pump including the armature unit.

  2. Description of the Related Art Conventionally, a structure in which a resin material is in close contact with and molded around an armature has been adopted as a measure against vibration suppression and waterproofing of the armature (see, for example, Patent Documents 1, 2, and 3). An armature unit structure that is molded integrally with the armature is employed as a countermeasure against an electrical short circuit outside the circuit board that is electrically connected to the armature (such a conventional armature). As an example of the structure of the unit, see, for example, Patent Document 4.

  The structure of a conventional armature unit such as Patent Document 4 will be described with reference to FIG. FIG. 8 is a schematic diagram showing a cross section of the armature unit in the stacking direction.

  Referring to FIG. 8, armature unit 1 is formed of armature 2 having a coil 2b formed by winding a conductive wire around stator core 2a, and a resin material disposed under armature 2. It is comprised from the circuit board 3, and the mold part 4 which molds the armature 2 and the circuit board 3 integrally.

JP-A-7-75280 JP-A-8-104797 JP 2003-333787 A JP 2003-47189 A

  However, when the armature 2 and the circuit board 3 are integrally molded with a resin material, particularly when the mold part 4 is exposed to the outside as a product, in order to improve the appearance of the mold part 4, high temperature and high pressure are used. It is necessary to mold with. When the circuit board 3 is molded at this high temperature and high pressure, the injection pressure when the molten resin material is injected is applied to the circuit board, and the circuit board 3 may be warped or deformed. As a result, the electrical connection between the electronic component (not shown) mounted on the circuit board 3 and the circuit board 3 is poor, and the wiring pattern (not shown) formed on the circuit board 3 is cracked. There is a possibility of causing poor conduction of the substrate 3. Further, when the circuit board 3 is molded at a high temperature, the heat resistance temperature of the electronic component is exceeded, and the electronic component itself may break down.

  On the other hand, when the mold part 4 is formed at a low temperature and a low pressure, the appearance of the mold part 4 is not good and it is treated as a defective appearance of the product.

  Moreover, in the structure which molds the assembly which consists of the armature 2 and the circuit board 3 as mentioned above, the mold part 4 is the whole circumference | surroundings of the circuit board 3 because of the structure of the metal mold | die used at the time of molding, or a molding defect. (If the circuit board 3 is not completely covered by the mold part 4, the vibration suppression measures and the waterproof measures will be insufficient, and the advantage obtained by applying the mold structure cannot be obtained sufficiently.) ). Therefore, after the mold part 4 is completed, a post-process (for example, filling the exposed part with a resin material) is required to prevent the circuit board 3 from being exposed to the molding part 4 and touching the outside air. , Manufacturing costs increase.

  The present invention has been made in view of the above problems, and the object of the present invention is to provide an armature unit that does not cause poor appearance of the mold part and poor conduction of the circuit board, a method for manufacturing the armature unit, and A motor and a pump including the armature unit are provided.

  According to the present invention, in an assembly including an armature, a circuit board, and an insulating part covering them, the insulating part is constituted by two insulating layers so as to cover at least the entire periphery of the circuit board.

  According to claim 1 of the present invention, the armature unit includes an armature, a circuit board, and an insulating portion that covers the armature and the circuit board, and the armature includes a thin magnetic steel plate. An annular stator core formed by laminating a plurality of coils and a coil formed by winding a conductive wire around the stator core, and the circuit board is disposed on one end side of the stator core in the laminating direction. And an end portion of the coil is electrically connected, and the insulating portion includes at least a first insulating layer provided in close contact with the entire periphery of the circuit board, and at least the stacking direction with respect to the circuit board. It has the 2nd insulating layer closely_contact | adhered to said 1st insulating layer in the one end side or the other end side, It is characterized by the above-mentioned.

  According to claim 1 of the present invention, at least the circuit board can be covered with the double insulating layer. Therefore, it is possible to prevent the circuit board from being completely exposed from the outside. As a result, it is possible to prevent an electrical short circuit that occurs due to external oil or water adhering to the circuit board. Therefore, a highly reliable armature unit can be provided.

  According to a second aspect of the present invention, according to the first aspect, the first insulating layer injects a molten first insulating material into a first mold in which the armature and the circuit board are arranged. Then, the second insulating layer is formed by solidification, and the second insulating layer is melted into a second mold in which an intermediate assembly including the armature, the circuit board, and the first insulating layer is disposed. It is characterized by being formed by injecting a material and then solidifying it.

  According to claim 2 of the present invention, the first and second insulating layers can be easily formed.

  According to claim 3 of the present invention, according to claim 2, when the molten first insulating material is injected into the first mold, the injection pressure of the molten second insulating material is the second It is characterized by being smaller than the injection pressure when being injected into the mold.

  According to the third aspect of the present invention, the first insulating layer can be formed without applying excessive stress to the circuit board. Therefore, it is possible to prevent warping and cracking of the circuit board and further electrical failure of the mounted component.

  According to a fourth aspect of the present invention, in accordance with any one of the first to third aspects, the second insulating layer is substantially the circumference except for the magnetic pole surface of the armature in addition to the first insulating layer. It adheres to the whole.

  According to claim 4 of the present invention, the gap between the magnetic pole face and the member facing the magnetic pole face can be narrowed by preventing the second insulating layer from being in close contact with the magnetic pole face of the armature.

  According to a fifth aspect of the present invention, according to any one of the first to third aspects, the second insulating layer is in close contact with substantially the entire periphery of the armature in addition to the first insulating layer. It is characterized by.

  According to claim 5 of the present invention, it is not necessary to add a member other than the second insulating layer or to perform a surface treatment in order to cover the entire periphery of the armature with the insulating layer by the second insulating layer.

  According to a sixth aspect of the present invention, in accordance with any one of the first to third aspects, the first insulating layer is in close contact with substantially the entire periphery except for the magnetic pole surface of the armature in addition to the circuit board. It is characterized by doing.

  According to the sixth aspect of the present invention, since the first insulating layer does not adhere to the magnetic pole surface of the armature, the gap between the magnetic pole surface and the member facing it can be narrowed.

  According to a seventh aspect of the present invention, in accordance with any one of the first to third aspects, the first insulating layer is in close contact with substantially the entire periphery of the armature in addition to the circuit board. To do.

  According to the seventh aspect of the present invention, it is not necessary to add a member other than the first insulating layer or to perform a surface treatment for covering the substantially entire periphery of the armature with the insulating layer by the first insulating layer.

  According to an eighth aspect of the present invention, according to any one of the first to seventh aspects, the first insulating layer has a hole that exposes a part of the circuit board, and the second insulating layer comprises: It is closely attached to a part of the circuit board through the hole.

  According to claim 8 of the present invention, the second insulating layer can prevent the circuit board from being exposed from the outside more completely.

  According to claim 9 of the present invention, according to any one of claims 2 to 8, the first or second insulating layer has a gate mark formed by the gate of the first or second mold. The armature is provided on the other end side in the stacking direction, on either the inner peripheral side or the outer peripheral side of the armature.

  According to the ninth aspect of the present invention, when the first or second insulating layer is formed, the first or second insulating layer can be formed without applying excessive stress to the circuit board. Therefore, it is possible to prevent warping and cracking of the circuit board and further electrical failure of the mounted component.

  According to a tenth aspect of the present invention, according to any one of the first to ninth aspects, a thermoplastic resin is used for the first insulating layer.

  According to the tenth aspect of the present invention, by using a thermoplastic resin for the first insulating layer, when the first insulating layer is heated when the second insulating layer is provided, the surface of the first insulating layer is melted. By doing, the adhesiveness of a 1st insulating layer and a 2nd insulating layer can improve. Therefore, the boundary between the first insulating layer and the second insulating layer can be completely blocked.

  According to an eleventh aspect of the present invention, in accordance with any one of the first to tenth aspects, a thermosetting resin is used for the second insulating layer.

  According to claim 12 of the present invention, according to claim 11, the thermosetting resin is BMC (Bulk Molding Compound).

  According to the eleventh and twelfth aspects of the present invention, the use of the thermosetting resin for the second insulating layer can suppress the deformation of the second insulating layer due to external heat. In particular, the heat dissipation of the armature unit can be improved by using BMC.

  According to claim 13 of the present invention, according to any one of claims 1 to 12, an elastomer is used for the second insulating layer.

According to claim 13 of the present invention, the second insulating layer can be formed with relatively simple equipment.

  According to claim 14 of the present invention, an armature having an annular stator core formed by laminating a plurality of thin magnetic steel plates, and a coil formed by winding a conductive wire around the stator core; And a circuit board to which one end of the stator core in the stacking direction is arranged and to which the end of the coil is electrically connected, and a first insulation provided in close contact with at least substantially the entire periphery of the circuit board And an insulating portion having a layer and a second insulating layer provided in close contact with the first insulating layer on one end side or the other end side in the stacking direction with respect to the circuit board. A first arrangement step of arranging the armature and the circuit board in the first mold, and a molten insulating material in the first mold in which the armature and the circuit board are arranged. The injection Then, by solidifying, an intermediate assembly including the armature, the circuit board, and the first insulating layer is disposed in a first molding step for molding the first insulating layer and a second mold. And a second forming step of forming the second insulating layer by injecting the molten insulating material into the second mold in which the intermediate assembly is arranged and then solidifying the second insulating layer. It is characterized by that.

  According to claim 14 of the present invention, an armature unit capable of covering at least a circuit board with a double insulating layer can be easily formed. In other words, this armature unit can prevent the circuit board from being completely exposed from the outside, and as a result, prevents an electrical short circuit that occurs due to external oil or water adhering to the circuit board. Therefore, a highly reliable armature unit can be easily formed.

  According to claim 15 of the present invention, according to claim 14, in the first arrangement step, the circuit board is supported by a support portion provided in the first mold, and the intermediate assembly includes A hole portion through which the circuit board is exposed is formed at a portion corresponding to the support portion, and the insulating material in the second molding step flows into the hole portion.

  According to the fifteenth aspect of the present invention, in the first arrangement step, the circuit board is moved by the flow of the molten insulating material when the first insulating layer is formed by providing the support portion for supporting the circuit board. Can be prevented. Further, a hole is formed in the first insulating layer corresponding to the support portion, but in the second molding step, the molten insulating material flows into the hole, thereby preventing the circuit board from being exposed to the outside. be able to.

  According to a sixteenth aspect of the present invention, in accordance with the fourteenth or fifteenth aspect, in the first or second molding step, the gate of the first or second mold is the other end side in the stacking direction, the stator core. It faces either the inner peripheral side of the stator or the outer peripheral side of the stator core.

  According to the sixteenth aspect of the present invention, when the first or second insulating layer is formed, the first or second insulating layer can be formed without applying excessive stress to the circuit board. Therefore, it is possible to prevent warping and cracking of the circuit board and further electrical failure of the mounted component.

  According to claim 17 of the present invention, there is provided a motor comprising the armature unit according to any one of claims 1 to 13, wherein the motor is opposed to the magnetic pole surface of the armature unit and A rotating part having a rotor magnet that rotates, and a bearing part that rotatably supports the rotating part.

  According to the seventeenth aspect of the present invention, it is possible to provide a highly reliable motor without an electrical short circuit on the circuit board.

  According to Claim 18 of this invention, it is a pump provided with the armature unit in any one of Claim 1 thru | or 13, Comprising: The armature unit opposes the magnetic pole surface of the said armature unit. Each of at least one rotating part having a rotor magnet that rotates relative to the liquid, an inflow port through which liquid from the outside flows in, and an outflow port through which the liquid flows out to the outside, and the liquid from the inflow port A pump chamber that forms a flow path for flowing through the outlet, and an impeller that is disposed in the pump chamber and that forms a flow in the liquid by rotating together with the rotating portion.

  According to claim 18 of the present invention, it is possible to provide a highly reliable pump without an electrical short circuit on the circuit board.

  According to the present invention, there are provided a highly reliable armature unit that does not cause an appearance defect of an insulating part and a conduction failure of a circuit board, a method of manufacturing the armature unit, and a motor and a pump including the armature unit. be able to.

<Overall structure of armature unit>
An embodiment of the entire structure of the armature unit of the present invention will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of an embodiment of an armature unit cut in the axial direction. Here, the axial direction in FIG. 1 is a direction along the axis J1. In addition, the upper and lower expressions in the following description are the expressions in the drawings and do not define the direction of gravity.

  Referring to FIG. 1, an armature unit 10 includes an armature 20, a circuit board 30 disposed on the lower side in the axial direction of the armature 20, and a mold part 40 (insulation) that covers the armature 20 and the circuit board 30. Equivalent).

  The armature 20 includes a stator core 21 formed by laminating thin magnetic steel plates in the axial direction of a predetermined axis J1, a coil 22 formed by winding a plurality of conductive wires around the stator core 21, and a stator core. The insulator 23 is disposed between the coil 21 and the coil 22 and is inserted from both sides of the stator core 21 in the axial direction to achieve electrical insulation between the stator core 21 and the coil 22.

  The stator core 21 has a core back portion 21a formed in an annular shape centered on a predetermined axis, and a plurality of teeth portions 21b formed through a gap in the circumferential direction extending from the core back portion 21a toward the predetermined axis. Have. The conductive wire is wound around the tooth portion 21 b to form the coil 22. The inner peripheral surface of the tooth portion 21b forms a magnetic pole surface.

  The insulator 23 is formed of a resin material having electrical insulation, and includes two members that insert the stator core 21 from both sides in the axial direction. The insulator 23 covers the outer surface other than the inner peripheral surface of the tooth portion 21b and the inner peripheral side and the inner peripheral surface of the axial end surface of the core back portion 21a. The insulator 23 has a pin (not shown) that is electrically and mechanically connected to the end of the conductive wire on which the coil 22 is formed. The insulator 23 is provided with an inner peripheral wall 23 a and an outer peripheral wall 23 b that prevent the coil 22 from collapsing on the radially inner side and the radially outer side of the coil 22, respectively.

  The circuit board 30 is formed of a resin material such as glass epoxy resin and paper phenol resin, and a conductive pattern constituting an electronic circuit is provided on the surface. Further, on the circuit board, electronic parts such as the integrated circuit 31 are mounted on predetermined portions of the conduction pattern by soldering. In addition, the circuit board 30 is soldered to the end of the pin of the armature 20, whereby the armature 20 and the circuit board 30 are electrically connected. Further, the position of the circuit board 30 in the axial direction is determined by contacting the outer peripheral wall 23 b of the insulator 23. Further, a power supply line (not shown) is connected to the circuit board 30 and is drawn out toward the external power supply.

  The mold part 40 is a first mold part 41 (first mold) made of a resin material that is in close contact with the coil 22 and the insulator 23 on the circuit board 30 side rather than the stator core 21 formed on the entire periphery of the circuit board 30 and on the circuit board 30 side. Equivalent to one insulating layer), a second mold part 42 (corresponding to the second insulating layer) made of a resin material in close contact with the entire periphery other than the outer surface of the first mold part 41 and the magnetic pole face of the armature 20; Consists of Here, the 1st mold part 41 should just be the shape which covers the whole circumference | surroundings of the circuit board 30 at least. In addition, even if a portion where the first or second mold part does not exist is formed around the circuit board or the armature in order to draw the power line to the outside, the second line is formed around the power line or the bushing member surrounding the power line. If the first or second mold layer is in close contact, the first or second mold portion is considered to substantially cover the circuit board or the armature.

  Since the second mold part 42 has a shape covering the outer surface of the first mold part 41, a minute hole is formed by a portion (a through hole 41a described later) or a nest where the first mold part 41 is not filled with a resin material. Even if it was made, all of these can be sealed by the second mold part 42. That is, since the entire periphery of the circuit board 30 is covered with the two insulating layers of the first and second mold parts 41 and 42, minute substances such as water and oil adhere to the circuit board 30 from the outside. The electrical short circuit which generate | occur | produces by this can be prevented. Therefore, a highly reliable armature unit can be provided.

  The first mold part 41 is preferably made of a thermoplastic resin. By using a thermoplastic resin for the first mold part 41, at least the surface of the first mold part 41 is melted by the heat when the second mold part 42 is formed on the outer surface of the first mold part 41, so that the second mold part Adhesion with 42 can be improved. And since the 1st mold part 41 is covered with the 2nd mold part 42 and is not exposed outside as a product, it is desirable to shape | mold at low temperature and low pressure. That is, when the molten resin material is injected into a predetermined mold at a low temperature and a low pressure, molding defects are likely to occur, but the first mold part 41 can be molded without applying stress to the circuit board 30. . Even if the first mold part 41 has a nest as a molding defect, it is covered with the second mold part 42, so that the appearance can be kept good and the circuit board 30 does not cause a conduction failure. Since it can be molded, a highly reliable armature unit can be provided.

  The second mold part 42 is preferably formed of a thermosetting resin. By forming the second mold part 42 that plays the role of the appearance of the product with the thermosetting resin, it is possible to prevent the second mold part 42 from being deformed by external heat. In particular, it is desirable to mold at a high temperature and a high pressure in order to improve the appearance. In particular, it is desirable to use BMC (Bulk Molding Compound) as the thermosetting resin. Since this BMC is a material excellent in heat dissipation and vibration absorption, it can promote the absorption of vibration of the armature 20 and the dissipation of the heat generated by the coil 22, and the BMC also has good surface hardness characteristics. It is possible to provide an armature unit having a good appearance that is hard to be damaged. The second mold part 42 may be formed of an elastomer. Since the elastomer has elasticity, it can absorb the vibration generated from the armature unit 10 when the armature unit 10 is incorporated. In particular, when a thermoplastic elastomer is used, it can be formed with relatively simple equipment. In addition, regarding the low temperature and low pressure as the molding conditions of the first mold part 42 described above and the high temperature and high pressure as the molding conditions of the second mold part 43, both are exemplified as compared with the general molding conditions. However, in consideration of various conditions, it is desirable that the first mold portion 42 be molded at a lower temperature and lower pressure than the second mold 41.

  Next, another embodiment of the armature unit will be described with reference to FIG. The present embodiment will be described with a focus on differences from the above-described embodiment, and the same or corresponding parts used in the above-described embodiment are used.

  In the above-described embodiment, as shown in FIG. 1, the first mold portion 41 is in close contact with the entire periphery of the circuit board 30 and the armature 20 on the circuit board 30 side. In this embodiment, as shown in FIG. The first mold part 41 is different in the configuration in which it is in close contact with the entire periphery of the circuit board 30 and the entire periphery except for the magnetic pole surface of the armature 20. Accordingly, the second mold part 42 in FIG. 1 is in close contact with the first mold part 41 and the remaining part of the armature 20 (part where the first mold part 41 is not in close contact). The second second mold part 42 is also different in the configuration in which most of the second mold part 42 is in close contact with the first mold part 43.

  Also in the armature unit 10 of the present embodiment, the entire periphery of the circuit board 30 is covered with the two insulating layers of the first and second mold portions 41 and 42 as in the above-described embodiment. Although it has the same effect, in particular, in this embodiment, since the area of the two insulating layers of the mold part 40 is increased, water and the like enter the armature 20 as well as the circuit board 30. This can be further prevented.

  Furthermore, although detailed description is omitted, the first and second mold parts 41 and 42 are not in close contact with the magnetic pole surface of the armature 20 in both of the above-described embodiments. However, it is good also as a structure covered with either the 1st or 2nd mold part 41,42. This magnetic pole surface faces a rotating part of a brushless motor, which will be described later, and if left exposed, the gap between the rotating part and the rotating part can be narrowed, and the magnetic efficiency can be increased. On the other hand, if the magnetic pole surface is covered with the first or second mold part 41, 42, the gap with the rotating part is increased by the thickness, and the magnetic efficiency is somewhat reduced. Rust treatment can be performed at the same time.

<Manufacturing method of armature unit>
Next, an embodiment of a method for manufacturing the armature unit 10 will be described with reference to FIGS. FIG. 3 is a flowchart showing manufacturing steps of the armature unit 10. 4 to 6 are schematic views showing the mold state in the flow of FIG. Here, the axial direction refers to the stacking direction of the stator cores 21. The arrows in FIGS. 5 and 6 indicate the direction in which the resin flows. The armature unit 10 used in the description of the manufacturing method is that of the embodiment shown in FIG. 1, but the armature unit 10 shown in FIG. 2 is substantially changed only by changing the configuration of the mold. Since it can be manufactured by the same manufacturing method, detailed description of the manufacturing method of the armature unit in FIG. 2 is omitted.

  Referring to FIG. 4, a mold 300 for molding the first mold portion 41 is arranged on the lower side in the axial direction and fixed to the first mold portion 310 on the fixed side, which is fixed on itself. And a movable second mold part 320 which is arranged on the upper side in the axial direction with respect to the one mold part 310 and is movable at least in the axial direction.

  The first mold part 310 includes an armature accommodating part 311 that accommodates the armature 20, and an annular lower exposed part that is exposed to the outside on the outer peripheral side from the insulator 23 of the core back part 21 a of the armature 20. 21a1 and an armature placement portion 312 that determines the position of the armature 20 in the axial direction by contacting the lower end portion 21b1 exposed to the outside on the inner peripheral side of the insulator 23 of the teeth portion 21b. . Further, the first mold part 310 forms an inner side of the armature accommodating part 311, substantially coincides with the inner diameter of the inner peripheral surface of the tooth part 21 b, and a cylindrical protrusion 313 that allows the inner peripheral surface of the tooth part 21 b to be inserted. Is provided. The cylindrical protrusion 313 determines the radial position of the armature 20.

  The second mold part 320 includes a circuit board housing part 321 for housing the circuit board 30, and an annular upper exposed part 21 a 2 exposed to the outside on the outer peripheral side from the insulator 23 of the core back part 21 a of the armature 20. And a contact portion 322 that contacts the first mold portion 310 and a gate portion 323 that injects resin into the circuit board housing portion 321.

  A lower support portion 313a that supports the circuit board 30 from the lower side is provided at a position facing the circuit board 30 in the axial direction on the upper surface of the cylindrical protrusion 313 of the first mold part 310. The second mold part 320 is provided with an upper support part 321a for pressing the circuit board 30 from the upper side at a position facing the circuit board 30 in the axial direction on the lower surface of the circuit board housing part 321. Therefore, the circuit board 30 fixed to the armature 20 is axially lowered by the outer peripheral wall 23c of the insulator 23 and the lower support portion 313a in the mold 300 before the first mold portion 41 is formed. It is supported from the side and clamped by being pressed from the upper side by the upper support portion 321a (corresponding to step S1 in FIG. 3, first arrangement step).

  In this state, referring to FIG. 5, after the molten resin is injected from the gate portion 323 of the second mold portion 320 toward the circuit board housing portion 321 and solidified, the first mold portion 41 is formed. (Corresponding to step S2 in FIG. 3, the first molding step). Here, the resin material to be used is desirably a thermoplastic resin. In the first mold portion 41, since the appearance does not need to be taken into consideration, it is desirable that the injection molding has good moldability.

  Further, the first mold part 41 in this state has a shape corresponding to the lower support part 313a and the upper support part 321a at a position corresponding to the lower support part 313a and the upper support part 321a. A through hole 41a (corresponding to a hole) is formed to expose a part of the through hole.

  Next, referring to FIG. 6, the intermediate assembly of the armature 20 and the circuit board 30 in which the first mold part 41 is formed is arranged in a mold 400 for molding the second mold part 42 (second arrangement). Equivalent to the process). The mold 400 is disposed on the lower side in the axial direction and is fixed to the first mold part 410 on the fixed side, and is disposed on the upper side in the axial direction from the first mold part 410, and the mold 400 itself is at least the shaft. And a movable second mold part 420 that is movable upward in the direction.

  The first mold portion 410 is mounted with an armature that determines the position of the armature 20 in the axial direction by contacting the armature accommodating portion 411 that accommodates the armature 20 and the lower end portion 21b1 of the armature 20. The mounting portion 412 includes a cylindrical protrusion 413 that is substantially the same as the inner diameter of a virtual circle formed on the inner peripheral surface of the tooth portion 21b and can be inserted into the inner peripheral surface of the tooth portion 21b. Moreover, the armature accommodating part 411 is formed via the lower end part and outer peripheral surface of the armature 20 through a gap. The upper surface of the cylindrical protrusion 413 and the lower surface of the first mold portion 41 are opposed to each other with a gap in the axial direction.

  The second mold part 420 includes a first mold housing part 421 facing the periphery of the first mold part 42 with a predetermined gap, and a gate part 422 for injecting resin into the first mold housing part 421. . The second mold part 420 abuts on the first mold part 410 to seal the assembly of the circuit board 30 and the armature 20 on which the first mold part 41 is formed.

  Then, after the molten resin is injected from the gate portion 422 into the first mold housing portion 421 and solidified, the second mold portion 42 is formed (corresponding to step S3 in FIG. 3, the second molding step). Here, the resin used for the second mold part 42 is desirably a thermosetting resin, particularly BMC. By using BMC, the heat dissipation of the armature unit 10 can be improved. The molding of the second mold part 42 is desirably press-fitting molding. The dimensional accuracy of the second mold part 42 can be ensured by press-fitting. Furthermore, in press-fitting molding, the hardness can be kept higher compared to injection molding. Accordingly, it is possible to have an appearance that is excellent in dimensional accuracy and hardly scratched.

  Further, the through hole 41a corresponding to the lower support portion 313a and the upper support portion 321a formed in the first mold portion 41 in the state of step S2 is the first mold housing portion in the molding of the second mold portion 42 in step S3. The resin 421 is filled with the injected resin. Therefore, the circuit board 30 can be completely prevented from being exposed from the outside. As a result, it is possible to prevent the circuit board 30 from being electrically short-circuited by external oil or water. At this time, even if a nest is formed as a molding defect of the first mold part 41, it is filled with the second mold part 42, so that the molding defect of the first mold part 41 can be eliminated.

  Further, when the second mold part 42 covers the periphery of the first mold part 41, the surface of the first mold part 41 is melted because the second mold part 42 is at a high temperature. Therefore, when the second mold part 42 is fixed to the first mold part 41, the boundary between the first mold part 41 and the second mold part 42 is in close contact. Therefore, it is possible to prevent oil or water from entering from this boundary.

  Next, an embodiment of another embodiment of the method for manufacturing the armature unit 10 will be described with reference to FIGS. The arrows in FIGS. 7 and 8 indicate the direction in which the resin flows. The present embodiment will be described with a focus on differences from the above-described embodiment, and the same or corresponding parts used in the above-described embodiment are used.

  In the above-described embodiment, as shown in FIGS. 4 to 6, the gate parts 323 and 422 of the second mold parts 320 and 420 used in the first and second molding steps are the upper surface of the circuit board 30. The resin material thus injected is provided at a position where it directly hits. On the other hand, in this embodiment, the gate part 323 of the second mold part 320 is located on the outer peripheral side of the armature 20 as shown in FIG. 7, and the gate part 422 of the second mold part 420 is As shown in FIG. 8, the armature 20 is located below. That is, in the manufacturing method of the present embodiment, since the gate portions 323 and 422 are positioned so as not to face the circuit board 30, the injection pressure when the resin reaches the circuit board 30 is the same as that in the above-described embodiment. It is somewhat weaker than that. As a result, the load on the circuit board 30 is alleviated, and warping and deformation of the circuit board 30 and further mounting failure of the electronic component can be prevented. Whether or not the manufacturing method of the present embodiment is adopted is determined by gate marks (not shown) formed on the surfaces of the first and second mold portions 42 and 43 at the portions facing the gate portions 323 and 422. be able to.

<Brushless motor>
Next, an embodiment of a brushless motor including the armature unit of the present invention will be described with reference to FIG. The armature unit here uses the armature unit 10 shown in FIG. 1, but the armature unit 10 shown in FIG. 2 can also be applied. FIG. 9 is a schematic cross-sectional view of an embodiment of the brushless motor of the present invention cut in the direction of the rotation axis.

  With reference to FIG. 9, the rotating part will be described first.

  The shaft 70 rotates in a freely rotatable manner, and the center of rotation is the rotation axis J1. A rotor magnet 80 is integrally formed on the shaft 70 so as to be fixed to the shaft 70. The rotor magnet 80 is provided with a shaft fixing portion 81 that is fixed to the shaft 70 and a magnetic drive portion 82 that faces the inner peripheral surface of the armature 20 via a small gap in the radial direction.

  Next, the fixing part will be described.

  The armature unit 10 is formed in a substantially cylindrical shape. Further, on the upper side in the axial direction of the cylindrical portion 11, an inner extension portion 12 is formed that is positioned on the upper side in the axial direction from the magnetic drive portion 82 of the rotor magnet 80 and extends radially inward from the inner peripheral surface of the magnetic drive portion 82. On the inner peripheral edge of the inner extension portion 12, an upper bearing holding portion 13 is formed integrally with the armature unit 10 and is formed into a substantially cylindrical shape by plastic working such as pressing a steel plate. The upper bearing holding portion 13 holds a ball bearing 50 serving as a bearing portion. A lid portion 13 a that covers the ball bearing 50 is formed on the upper side in the axial direction of the upper bearing holding portion 13. Further, a preload spring 90 is disposed between the ball bearing 50 and the lid portion 13a in the axial direction so as to contact the outer ring of the ball bearing 50 and apply preload to the ball bearing 50.

  On the lower side in the axial direction of the cylindrical portion 11 of the armature unit 10, a lower bearing holding portion 14 that is formed into a substantially cylindrical shape by plastic processing such as press processing of a steel plate is fixed. A ball bearing 51 is held by the lower bearing holding portion 14. The lower bearing holding portion 14 is formed with an abutting portion 14 a that abuts the outer ring on the lower side in the axial direction of the ball bearing 51 and applies a preload to the ball bearing 51. Further, the shaft 70 can be freely rotated by the ball bearings 50 and 51.

  By using the armature unit 10 of the present invention for this brushless motor, it is possible to provide a brushless motor that does not cause an electrical short circuit on the circuit board 30 and is low in vibration. The armature unit 10 is integrally provided with the upper bearing holding portion 13. If an elastomer is used for the second insulating layer 42, the second insulating layer 42 is attached to the outer periphery of the upper bearing holding portion 13. Can be used as a cushioning material.

<Pump>
Next, an embodiment of a pump including the armature unit 10 of the present invention will be described with reference to FIG. The armature unit 10 used here is the one shown in FIG. FIG. 10 is a schematic cross-sectional view cut in the axial direction showing an embodiment of the pump of the present invention.

  Referring to FIG. 10, the pump includes a pump chamber 100, and a motor 200 including a rotating unit 210 accommodated in the pump chamber 100 and a fixing unit 220 including the armature unit 10 adjacent to the pump chamber 100. The

  The motor 200 is disposed on the outer peripheral surface side of the first casing 110 and is fixed to the outer peripheral surface side of the first casing 110 formed in a substantially bottomed cylindrical shape. And a rotating part 210 having a rotor magnet 211 that rotates around the rotation axis J1.

  A connector 221 that enables electrical connection with the outside is molded integrally with the armature unit 10 on the outer peripheral side of the fixed portion 220. The connector 221 is also electrically connected to the circuit board 30.

  A protrusion 111 is formed on the bottom 111 of the first casing 110 that is formed on the lowermost side in the axial direction and is coaxial with the rotation axis J1 and extends on the upper side in the axial direction. In the upper part of the protrusion 112, a recess 113 is formed that opens coaxially with the rotation axis J1 and opens upward in the axial direction. A shaft 120 that is coaxial with the rotation axis J1 is fixed to the recess 113.

  The rotating part 210 is inserted into the shaft 120 and is arranged so as to be opposed to each other with a minute gap in the radial direction. The rotating part 210 is integrally formed with the sleeve 212 and fixes the substantially cylindrical rotor magnet 211. And a base 213 to be provided. The outer peripheral surface of the rotor magnet 211 is disposed so as to face the inner peripheral surface of the tooth portion 21b of the armature 20 via a small gap in the radial direction. In this gap, the cylindrical portion 114 of the first casing 110 is disposed. By this cylindrical portion 114, the rotor magnet 211 and the armature unit 10 are isolated from each other, and liquid such as water can be prevented from entering the fixing portion 220 side.

  Further, on the opposite side of the rotor magnet 211 in the axial direction, impellers 214 composed of a plurality of blades are formed at equal intervals in the circumferential direction.

  A second casing 130 is formed on the upper side of the first casing 110 in the axial direction so as to accommodate the base 213 and the impeller 214. A pump chamber 100 is formed by a space surrounded by the first casing 110 and the second casing 130.

  By using the armature unit 10 of the present invention for this pump, even if a liquid such as water leaks from the first casing 110, the circuit board 30 is not completely exposed to the outside by the second mold part 42. It is possible to prevent the circuit board 30 from causing an electrical short circuit. Therefore, a highly reliable pump can be provided.

  The structure and manufacturing method of the armature unit 10 and the embodiment of the brushless motor and pump including the armature unit 10 have been described above. However, the present invention is not limited to the above-described embodiment. Various modifications are possible within the scope of the claims.

  For example, in the armature unit 10 of the present invention, the insulator 23 is used, but the present invention is not limited to this. Since it is only necessary to prevent an electrical short circuit between the stator core 21 and the coil 22, for example, the periphery of the stator core 21 may be insulated and coated instead of the insulator 23.

  For example, the motor and pump provided with the armature unit 10 of the present invention are not limited to the shapes of the above-described embodiments.

The schematic cross section cut in the axial direction which shows one form of the Example of the armature unit of this invention. The schematic cross section cut in the axial direction which shows one form of the other Example of the armature unit of this invention. The flowchart which shows one form of the Example of the manufacturing method of the armature unit of this invention. The schematic cross section cut in the axial direction which shows the state of step S1 of the flowchart of FIG. The schematic cross section cut in the axial direction which shows the state of step S2 of the flowchart of FIG. The schematic cross section cut in the axial direction which shows the state of step S3 of the flowchart of FIG. FIG. 4 is a schematic cross-sectional view cut in the axial direction showing the state of step S2 in the flowchart of FIG. 3, which is an embodiment of the armature unit manufacturing method of the present invention. FIG. 4 is a schematic cross-sectional view taken along the axial direction showing the state of step S3 in the flowchart of FIG. 3, which is an embodiment of another method for manufacturing an armature unit of the present invention. The schematic cross section cut in the axial direction which shows one form of the Example of the motor provided with the armature unit of this invention. The schematic cross section cut in the axial direction which shows one form of the Example of the pump provided with the armature unit of this invention. The schematic cross section cut in the axial direction which shows the conventional armature unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Armature unit 20 Armature 21 Stator core 21a Core back part 21b Teeth part 22 Coil 30 Circuit board 40 Mold part (insulation part)
41 First mold part (first insulation layer)
41a Through-hole 42 Second mold part (second insulating layer)
313a Lower support part (support part)
321a Upper support part (support part)
50, 51 Ball bearing (bearing part)
80 rotor magnet 100 pump chamber 110 first casing 114 cylindrical portion 130 second casing 210 rotating portion 215 impeller 220 fixed portion

Claims (18)

An armature unit comprising an armature, a circuit board, and an insulating portion covering the armature and the circuit board,
The armature has an annular stator core formed by laminating a plurality of thin magnetic steel plates, and a coil formed by winding a conductive wire around the stator core,
The circuit board is disposed on one end side in the stacking direction of the stator core, and an end of the coil is electrically connected,
The insulating portion includes at least a first insulating layer provided in close contact with the entire periphery of the circuit board, and at least the first insulating layer on one end side or the other end side in the stacking direction with respect to the circuit board. A second insulating layer provided in close contact,
An armature unit characterized by that. The first insulating layer is formed by injecting a molten first insulating material into a first mold in which the armature and the circuit board are arranged, and then solidifying the first insulating layer,
The second insulating layer is solidified after injecting a molten second insulating material into a second mold in which an intermediate assembly including the armature, the circuit board, and the first insulating layer is disposed. The armature unit according to claim 1, wherein the armature unit is formed by:   An injection pressure when the molten first insulating material is injected into the first mold is smaller than an injection pressure when the molten second insulating material is injected into the second mold. The armature unit according to claim 2.   4. The electric machine according to claim 1, wherein, in addition to the first insulating layer, the second insulating layer is in close contact with substantially the entire periphery excluding the magnetic pole surface of the armature. Child unit.   4. The armature unit according to claim 1, wherein the second insulating layer is in close contact with substantially the entire periphery of the armature in addition to the first insulating layer. 5.   The armature unit according to any one of claims 1 to 3, wherein the first insulating layer is in close contact with the entire periphery except for the magnetic pole surface of the armature in addition to the circuit board.   The armature unit according to any one of claims 1 to 3, wherein the first insulating layer is in close contact with the entire periphery of the armature in addition to the circuit board. The first insulating layer has a hole that exposes a part of the circuit board;
The armature unit according to claim 1, wherein the second insulating layer is in close contact with a part of the circuit board through the hole.   In the first or second insulating layer, a gate mark formed by the gate of the first or second mold is formed on the other end side in the stacking direction of the armature, the inner peripheral side and the outer peripheral side of the armature. The armature unit according to claim 2, wherein the armature unit is provided in any one of the above.   The armature unit according to claim 1, wherein a thermoplastic resin is used for the first insulating layer.   The armature unit according to claim 1, wherein a thermosetting resin is used for the second insulating layer.   The armature unit according to claim 11, wherein the thermosetting resin is BMC (Bulk Molding Compound).   The armature unit according to claim 1, wherein an elastomer is used for the second insulating layer. An armature having an annular stator core formed by laminating a plurality of thin magnetic steel plates, and a coil formed by winding a conductive wire around the stator core;
A circuit board that is disposed on one end side in the stacking direction of the stator core and to which an end of the coil is electrically connected;
At least a first insulating layer provided in close contact with the entire periphery of the circuit board and at least a first insulating layer on one end side or the other end side in the stacking direction with respect to the circuit board. An insulating part having a second insulating layer;
A method for manufacturing an armature unit comprising:
A first placement step of placing the armature and the circuit board on a first mold;
A first molding step of molding the first insulating layer by injecting a molten insulating material into the first mold in which the armature and the circuit board are disposed, and then solidifying the first insulating layer;
A second placement step of placing an intermediate assembly composed of the armature, the circuit board, and the first insulating layer on a second mold;
A second molding step of molding the second insulating layer by injecting a molten insulating material into the second mold in which the intermediate assembly is disposed, and then solidifying;
A method of manufacturing an armature unit, comprising: In the first arrangement step, the circuit board is supported by a support portion provided in the first mold,
The intermediate assembly is formed with a hole that exposes the circuit board at a portion corresponding to the support portion.
The method for manufacturing an armature unit according to claim 14, wherein the insulating material in the second forming step also flows into the hole.   In the first or second molding step, the gate of the first or second mold faces either the other end side in the stacking direction, the inner peripheral side of the stator core, or the outer peripheral side of the stator core. 16. The method for manufacturing an armature unit according to claim 14, wherein the armature unit is manufactured. A motor comprising the armature unit according to claim 1,
A rotating part having a rotor magnet that rotates relative to the armature unit opposite to the magnetic pole surface of the armature unit;
A bearing portion that rotatably supports the rotating portion;
A motor comprising: A pump comprising the armature unit according to any one of claims 1 to 13,
A rotating part having a rotor magnet that rotates relative to the armature unit opposite to the magnetic pole surface of the armature unit;
A pump chamber that has at least one inflow port through which liquid from the outside flows in and an outflow port through which the liquid flows out to the outside, and forms a flow path for flowing the liquid from the inflow port to the outflow port When,
An impeller disposed in the pump chamber and configured to form a flow in the liquid by rotating together with the rotating unit;
A pump comprising:

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