JP6229327B2 - motor - Google Patents

Description

  The present invention is, for example, a motor that is supported by a tilt mechanism and rotates a hollow annular rotor, such as an optical device such as a laser head rotating three-dimensional scanner, a gantry rotating unit of an X-ray CT apparatus, or the like. The present invention relates to a motor that can be used in medical equipment.

  In Patent Document 1, the field portion is disposed at the outer peripheral end portion of the rotary table to be a rotor, and the armature portion to be fixed is a stator, so that the rotary table is driven at the outer peripheral end portion. As a result, a technology of a coreless linear motor (motor) of a plane facing type (axial gap type) that drives the rotary table with a small thrust is described. Patent Document 2 describes an X-ray CT apparatus capable of tilting a gantry having an annular rotating ring at a large tilt angle.

Japanese Patent Application Laid-Open No. 2006-333651 JP2013-009819A

  However, in the motor described in Patent Document 1, when a large thrust is to be obtained while maintaining a large-diameter hollow hole, it is necessary to increase the rotor outer diameter side. That is, when the motor described in Patent Document 1 is supported by a tilt shaft as described in Patent Document 2, it is difficult to suppress the protrusion length of the tilt shaft from the axis. Further, the motor described in Patent Document 1 needs to form a magnetic path by sandwiching the stator between two rotors, and is difficult to reduce in weight. Further, the motor described in Patent Document 1 is difficult to reduce in weight because it is necessary to incorporate a thick magnet in order to maintain a sufficient amount of magnetic flux in a gap that sandwiches the stator between the rotors. As described above, the motor described in Patent Document 1 has a large inertia in the tilt direction. Therefore, the motor has a large-diameter hollow hole and is not suitable for an application in which the axis is tilted by an external mechanism.

  The present invention has been made in view of the above, and an object of the present invention is to provide a motor capable of suppressing the inertia in the tilt direction.

In order to solve the above-described problems and achieve the object, a motor of the present invention includes a hollow annular hollow shaft, a motor rotor including a plurality of magnets arranged on the outer circumference and in the circumferential direction of the hollow shaft, and the motor rotor. A motor base that surrounds a radially outer side of the motor base and can be swung by a tilt shaft, a bearing that rotatably supports the hollow shaft on an inner wall of the motor base, and a part of the plurality of magnets that are attached to the motor base When the total number of the motor stators is Sn, the plurality of motor stators are represented by θe in the following formula (1). It is characterized by being arranged with a phase shifted by an electrical angle.
θe = 360 ° / (2 × (Sn)) (1)

  With the above configuration, the motor can obtain a smooth rotation by canceling the cogging torque caused by the end portion of the motor stator due to the phase relationship of the motor stator.

  As a preferred aspect of the present invention, the motor base includes a first tilt shaft and a second tilt shaft extending in opposite directions so as to be parallel to the tilt axis, and the plurality of motor stators includes the first tilt shaft. It is preferable that the arrangement is divided into the vicinity and the vicinity of the second tilt shaft.

  With the above configuration, the motor can reduce the inertia in the tilt direction. Since the inertia in the tilt direction is small and the resonance frequency can be increased, the motor can rotate the motor rotor at high speed.

  As a desirable mode of the present invention, it is preferable that the plurality of motor stators include a stator core including an exciting coil and a pseudo stator core that does not energize the exciting coil or does not include the exciting coil.

  With the above configuration, the cogging torque caused by the end portion of the motor stator is offset by the phase relationship between the stator core having the exciting coil and the pseudo stator core, and smooth rotation can be obtained.

  As a desirable aspect of the present invention, the plurality of motor stators include a plurality of stator cores including excitation coils, and are driven by an amplifier that supplies electric power to the excitation coils. It is preferable that at least one of the motor stators is driven by a separate amplifier.

  With the above-described configuration, the motor can flow a motor current according to the energization timing of each motor stator even if there is a deviation in electrical angle between the plurality of motor stators, so that smooth rotation can be obtained.

  As a desirable aspect of the present invention, the plurality of motor stators include a plurality of stator cores including excitation coils, and are driven by an amplifier that supplies electric power to the excitation coils. It is preferable that the amplifier is driven by the amplifier different from the amplifier that drives the motor stator.

  With the above-described configuration, the motor can flow a motor current according to the energization timing of each motor stator even if there is a deviation in electrical angle between the plurality of motor stators, so that smooth rotation can be obtained.

  As a desirable mode of the present invention, it is preferred that the motor base is penetrated by the hollow shaft, and the magnet is disposed on an outer periphery where the hollow shaft is exposed.

  With the above configuration, when the motor tries to obtain a large thrust while maintaining a large-diameter hollow hole in the hollow shaft, the motor can expand the area where the magnet and the stator core overlap.

  In addition, with the above configuration, the magnet and the first stator core are opposed to each other instead of facing each other. And since a motor stator has a core, even if it uses a thin magnet, the operating point of a magnet can be maintained. Since a thin magnet is used, the motor can reduce the inertia in the tilt direction. Further, the motor directly applies a rotational force to the magnet without using an indirect transmission mechanism such as a gear. And a motor becomes what is called a direct drive motor, and can rotate a load body directly. Further, the motor can be positioned with high accuracy.

  As a desirable mode of the present invention, it is preferable that the magnet has a rectangular shape when viewed from the outer diameter side toward the rotation center.

  With the above configuration, the motor can suppress a strong cogging torque caused by the end portion of the stator core without attaching a skew diagonally on the surface and adding a skew. For this reason, the magnet does not have to be a magnet having a shape in which a flat plate is twisted, and can be easily molded and the cost of the motor can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the motor which can suppress the inertia of a tilt direction can be provided.

FIG. 1 is a perspective view illustrating an appearance of a motor according to the first embodiment. FIG. 2 is a plan view of the motor according to the first embodiment. FIG. 3 is a partial cross-sectional view schematically showing the configuration of the motor according to the first embodiment taken along the A-Zr-B cross section shown in FIG. 2. FIG. 4 is a partial cross-sectional view schematically showing the configuration of the motor according to the first embodiment taken along the C-Zr-D cross section shown in FIG. FIG. 5 is a partially enlarged view showing the motor stator shown in FIG. 2 in an enlarged manner. FIG. 6 is a partial cross-sectional view schematically showing an arrangement of magnets of the motor according to the first embodiment. FIG. 7 is a partial cross-sectional view schematically showing the arrangement of the teeth of the stator core of the motor according to the first embodiment. FIG. 8 is an explanatory diagram for explaining a relationship between the motor and the tilt mechanism according to the first embodiment. FIG. 9 is a diagram showing cogging torque generated due to the stator core end portion of the motor stator. FIG. 10 is an explanatory diagram for explaining a state in which a plurality of motor stators cancels cogging torque generated due to the end portion of the stator core. FIG. 11 is a plan view of the motor according to the second embodiment. FIG. 12 is a plan view of the motor according to the third embodiment. FIG. 13 is an explanatory diagram for explaining a state in which a plurality of motor stators cancels cogging torque generated due to the end portion of the stator core. FIG. 14 is a plan view of the motor according to the fourth embodiment. FIG. 15 is an explanatory diagram for explaining a state in which a plurality of motor stators cancels cogging torque caused by the end portion of the stator core. FIG. 16 is an explanatory diagram for explaining an optical apparatus to which the motor of this embodiment is applied.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

(Embodiment 1)
FIG. 1 is a perspective view illustrating an appearance of a motor according to the first embodiment. FIG. 2 is a plan view of the motor according to the first embodiment. As shown in FIG. 1 and FIG. 2, the motor 1 has a motor stator 30A and a motor stator 30B, which are stators (hereinafter referred to as motor stators) maintained in a stationary state, and a motor stator 30A and a motor stator 30B. The motor rotor 10 is a rotor (hereinafter referred to as a rotor) that is rotatably arranged, and a motor base 30 that fixes the motor stator 30A and the motor stator 30B.

  The motor rotor 10 includes a hollow shaft 11, a rotor yoke 41, and a magnet 42. The hollow shaft 11 is a hollow annular cylindrical body that surrounds the hollow hole 10H with an inner wall. The rotation center Zr of the hollow shaft 11 coincides with the center of the inner wall or the center of the outer wall of the hollow shaft 11. The hollow shaft 11 is an output shaft that transmits rotation to the outside.

  The motor base 20 has a substantially plate-shaped housing base 21 and a tilt shaft (first tilt shaft) 22A near one end in the X direction of the housing base 21, and a tilt shaft (second tilt shaft) at the other end in the X direction. ) 22B. The housing base 21 swings in the rotation direction Rtilt about a tilt axis Axt connecting the center of the tilt shaft 22A and the center of the tilt shaft 22B. In the motor base 20 according to the first embodiment, the motor stator 30 </ b> A and the motor stator 30 </ b> B are fixed to one surface 21 f of the housing base 21.

  For example, one of the tilt shafts 22A and 22B is fixed on a surface 23 of a machine base of an apparatus such as an optical apparatus or a medical apparatus. Therefore, the motor base 20 can swing around the tilt axis Axt. The motor stator 30A and the motor stator 30B are disposed on the tilt axis Axt and have a positional shift that is not line-symmetric on the tilt axis Axt. For this reason, in the arrangement of the motor base 20, in the motor 1, the motor stator 30A is biased near the tilt shaft 22A, and the motor stator 30B is biased near the tilt shaft 22B. As described above, the motor base 20 includes the tilt shaft 22A and the tilt shaft 22B extending in opposite directions so as to be parallel to the tilt axis Axt, and the plurality of motor stators 30A and 30B are tilted in the vicinity of the tilt shaft 22A. They are arranged separately from the vicinity of the shaft 22B. For this reason, in the motor base 20, the protrusion length from the axial center of the tilt axis Axt is suppressed. Further, by reducing the mass of the motor stator 30A and the motor stator 30B applied to the portion of the motor base 20 that is away from the axis of the tilt axis Axt, the motor 1 can have the inertia in the tilt direction Ft shown in FIG. Can be suppressed.

  FIG. 3 is a partial cross-sectional view schematically showing the configuration of the motor according to the first embodiment taken along the A-Zr-B cross section shown in FIG. 2. FIG. 4 is a partial cross-sectional view schematically showing the configuration of the motor according to the first embodiment taken along the C-Zr-D cross section shown in FIG.

  The motor base 20 is penetrated by the hollow shaft 11. The bearing device 14 rotatably supports the hollow shaft 11 on the inner wall of the motor base 20. For this reason, the motor 1 can rotate the motor rotor 10 with respect to the housing base 21, the motor stator 30A, and the motor stator 30B.

  The bearing device 14 is a rear combination angular contact ball bearing. The outer ring is fixed to the inner wall of the housing base 21, and the inner ring is fixed to the outer periphery of the hollow shaft 11. The rotor yoke 41 is fixed to the hollow shaft 11 in the axial direction with a bolt (not shown), thereby bringing the inner ring end surfaces of the bearing device 14 fitted into the hollow shaft 11 into close contact with each other. As a result, a preload is applied to the bearing device 14.

  The bearing device 14 is a back combination angular contact ball bearing. For this reason, the bearing device 14 becomes thin, and a hollow hole 10H having a large diameter can be secured in the hollow shaft 11. Further, the angular ball bearing can be applied with a preload without mounting a mechanical component for applying a preload on the motor rotor 10. For this reason, the motor rotor 10 can be reduced in weight, and the inertia in the tilt direction Ft can be reduced. The bearing device 14 has been described as an example using a thin back combination angular contact ball bearing. In the motor 1 according to the first embodiment, the bearing device 14 is not limited to the angular ball bearing, and is appropriately changed depending on the installation space, the friction torque, the rotation speed, and the like. For example, the bearing device 14 may have a structure in which two single-row four-point contact ball bearings or deep groove ball bearings are arranged to apply preload.

  A magnet 42 is disposed on the outer periphery where the hollow shaft 11 is exposed via a rotor yoke 41. A plurality of magnets 42 are arranged along the outer periphery of the rotor yoke 41 and in the circumferential direction Fr. The magnet 42 is a permanent magnet, and the S pole and the N pole are alternately arranged at equal intervals in the circumferential direction Fr of the rotor yoke 41. As a result, the number of poles of the motor rotor 10 shown in FIG. 2 is 96 poles in which N poles and S poles are alternately arranged in the circumferential direction of the rotor yoke 41 on the outer peripheral side of the rotor yoke 41. The number of poles of the magnet 42 is an example, and a plurality of poles may be used. The magnet 42 is an arc-shaped permanent magnet of an Nd—Fe—B magnet (neodymium magnet) having a high energy product. For this reason, a gap can be provided between adjacent magnets 42 to suppress the mass of the motor rotor 10. The motor 1 can reduce the inertia in the tilt direction Ft by the gap between the magnets 42.

  The rotor yoke 41 is annular, the inner periphery of the rotor yoke 41 is in contact with the outer periphery of the hollow shaft 11, and the magnet 42 is fixed to the outer periphery of the rotor yoke 41. The rotor yoke 41 is made of, for example, low carbon steel, and a magnetic path can be secured even in the rotor yoke 41 having a reduced thickness. Further, the rotor yoke 41 can reduce the inertia in the tilt direction Ft by being thin. The rotor yoke 41 has a surface treated with electroless nickel plating. In addition, although the example using the cyclic | annular low carbon steel to which electroless nickel plating was given was demonstrated as the rotor yoke 41, a material and surface treatment are not limited to Embodiment 1, Reasons, such as a use environment As appropriate. For example, the rotor yoke 41 may be another magnetic material such as martensitic stainless steel, although the magnetic properties are inferior.

  The magnet 42 is bonded and fixed to the rotor yoke 41 with an epoxy adhesive. Thereby, the stress which arises by the difference of the linear expansion coefficient of the material of the magnet 42 and the material of the rotor yoke 41 can be relieved. For example, even when the diameter of the motor rotor 10 is increased and the diameter of the rotor yoke 41 is increased, it is possible to suppress the peeling of the magnetic pole from which the magnet 42 is peeled off. Further, the rotor yoke 41 subjected to the surface treatment by electroless nickel plating can obtain high adhesive strength with respect to the epoxy adhesive. In addition, by adhering the magnet 41 having the epoxy coating on the surface to the rotor yoke 41, the periphery of the magnet 42 is covered with the epoxy resin, and the magnetic pole peeling can be suppressed. In addition, although the magnet 42 demonstrated in the example using the Nd-Fe-B type | system | group magnet (neodymium type magnet) to which the epoxy coating was given, the material and coating are not limited to Embodiment 1, and a motor is used. It is appropriately changed depending on necessary torque, use environment or compatibility with adhesive. For example, the surface of the magnet 42 may be subjected to electrolytic nickel plating.

  The hollow inner wall of the motor base 20, the rotor yoke 41, and the hollow shaft 11 are all annular. The rotor yoke 41 and the hollow shaft 11 are disposed concentrically around the rotation center Zr.

  The motor stator 30A and the motor stator 30B are not continuous and have a segment shape. The motor stator 30A includes a first stator core 31A and an excitation coil 32. The motor stator 30B includes a second stator core 31B and an excitation coil 32. The second stator core 31B has the same shape as the first stator core 31A. In the motor stator 30A, an exciting coil 32 is wound around a first stator core 31A. In the motor stator 30B, the exciting coil 32 is wound around the second stator core 31B. The motor stator 30A and the motor stator 30B are connected to wiring for supplying power from the power source, and power is supplied from the motor control circuit 90 described later to the exciting coil 32 through this wiring. ing.

  FIG. 5 is a partially enlarged view showing the motor stator shown in FIG. 2 in an enlarged manner. In the first embodiment, the motor stator 30B has the same configuration as the motor stator 30A, and thus the description thereof is omitted. The motor stator 30A is an arc-shaped laminated iron core in which a plurality of teeth (saliency poles) 31T are formed at equal intervals in the circumferential direction by laminating laminated materials of non-oriented electrical steel sheets. The material of the motor stator 30A is appropriately changed for reasons such as the detailed shape and the manufacturing process, and other electromagnetic materials such as a dust core may be used.

  The magnet 42 and the teeth 31T of the first stator core 31A are circumferentially opposed rather than planarly opposed. Since the operating point of the magnet can be maintained even if a thin magnet is used as the magnet 42, the motor 1 can reduce the inertia in the tilt direction Ft of the motor rotor 10.

  For example, the first stator core 31A includes nine teeth (saliency poles) 31T shown in FIG. 5 that protrude toward the inner diameter side of an arcuate back yoke having an opening angle θs of 30 ° shown in FIG. The exciting coil 32 is a linear electric wire. The exciting coil 32 is wound around the teeth 31T of the first stator core 31A via an insulator (insulating material). The exciting coil 32 is clockwise (in the direction opposite to the circumferential direction Fr) U-phase forward winding 32Ua, U-phase reverse winding 32Ub, U-phase forward winding 32Ua, V-phase forward winding 32Va, V-phase reverse winding 32Vb, V-phase. The normal winding 32Va, the W phase forward winding 32Wa, the W phase reverse winding 32Wb, and the W phase forward winding 32Wa are connected in this order. The teeth 31T face a part of the plurality of magnets 42 with a magnetic gap G therebetween.

  With the above configuration, since the first stator core 31A serves as a magnetic path, it is sufficient if at least one magnet 42 is arranged in the circumferential direction Fr. For this reason, the motor rotor 10 can be reduced in weight. As a result, the motor 1 can reduce the inertia in the tilt direction Ft.

  In the motor 1 according to the first embodiment, the number of rotor poles facing the motor stator 30A or the motor stator 30B is (96 poles / (360 ° / 30 °)) = 8 poles. On the other hand, since the motor stator 30A or the motor stator 30B includes nine teeth 31T, the motor 1 according to the first embodiment is converted into a surface magnet type rotary brushless motor and has a slot of 8 poles and 9 slots. It is a combination configuration.

  For example, an 8-pole 9-slot slot combination configuration converted to a surface magnet type rotary brushless motor is a fractional slot in which the relationship between the number of magnetic poles and the number of slots is not 2: 3, and the cogging force is small and it rotates smoothly. . In this way, the fractional slot configuration in which the relationship between the number of magnetic poles and the number of slots is not 2: 3 is the smallest in the number of magnetic poles and the number of slots compared to the configuration of integer slots in which the relationship between the number of magnetic poles and the number of slots is 2: 3. Since the common multiple is a large value, the cogging torque caused by the slot combination can be suppressed. Thus, the least common multiple of the number of magnetic poles and the number of slots is the number of cogging torque peaks due to the slot combination inherent in the motor, and the larger the number of cogging torque peaks, the more the amplitude is offset and distributed. In addition, the amplitude of the cogging torque becomes small. Note that the relationship between the number of magnetic poles and the number of slots is appropriately changed depending on the overall shape and the magnetic pole shape. The relationship between the number of magnetic poles and the number of slots may be other fractional slot configurations such as 10 poles, 9 slots, 10 poles, 12 slots, or 14 poles, 14 slots. In applications where the cogging torque due to the slot combination inherent in the motor is not a problem, an integer slot configuration may be used.

  When the motor 1 according to the first embodiment tries to obtain a large thrust while maintaining the hollow hole 10H having a large diameter in the hollow shaft 11, the hollow shaft 11 penetrates the motor base 20, and thus the hollow shaft 11 11 can be extended in the axial direction (axial direction of the rotation center Zr) without increasing the outer diameter direction. For this reason, the motor 1 can expand the area where the magnet 42 and the teeth 31T of the first stator core 31A face each other.

  FIG. 6 is a partial cross-sectional view schematically showing an arrangement of magnets of the motor according to the first embodiment. FIG. 7 is a partial cross-sectional view schematically showing the arrangement of the teeth of the stator core of the motor according to the first embodiment. For example, when the magnet 42 has a length 42z in the axial direction of the rotation center Zr and a width 42w in the circumferential direction Fr, the thrust is increased by extending the length 42z in the axial direction of the rotation center Zr. Can do. Similarly, when the tooth 31T has the axial length 31Tz of the rotation center Zr and the width 31Tw in the circumferential direction Fr, the thrust is increased by extending the axial length 31Tz of the rotation center Zr. be able to.

  FIG. 8 is an explanatory diagram for explaining a relationship between the motor and the tilt mechanism according to the first embodiment. The tilt mechanism according to the first embodiment is a rotation mechanism by the tilt motor 100 and includes the tilt motor 100, the machine base 51, and the motor control circuit 90.

  As shown in FIG. 8, when a motor rotation command i is input from an external computer, the motor control circuit 90 outputs a drive signal from a CPU (Central Processing Unit) 91 to a three-phase amplifier (AMP) 92. The drive current Mi is supplied from the AMP 92 to the motor 1. In the motor 1, the exciting coil of the motor stator 30 </ b> A is excited by the three-phase sinusoidal driving current Mi, and directly applies a rotational force to the magnet 42 side. Similarly, the plurality of motor stators 30 </ b> A and 30 </ b> B include a plurality of stator cores 31 </ b> A and 31 </ b> B including excitation coils 32, and each of the plurality of motor stators 30 </ b> A and 30 </ b> B by two AMPs 92 that supply power to each of the excitation coils 32. Are driven by different AMPs 92. For this reason, the motor 1 can flow a motor current according to the energization timing of each of the motor stators 30A and 30B even if there is a deviation of the electrical angle between the plurality of motor stators 30A and 30B, so that smooth rotation can be obtained. it can. When the motor rotor 10 is rotated by receiving the rotational force, a detection signal Sr is output from an angle detector such as an annular encoder 94 that detects the rotation angle of the motor rotor 10. Based on the digital information of the detection signal Sr, the motor control circuit 90 determines whether or not the motor rotor 10 has reached the command position, and when it reaches the command position, stops the drive signal to the AMP 92. As described above, when a motor rotation command i such as a speed command or a position command is input, the motor control circuit 90 calculates the rotation speed or position of the motor rotor 10 so as to follow the command i, and drives the motor stator 30A. The current Mi is output.

  As shown in FIG. 8, when a motor rotation command i is input from an external computer, the motor control circuit 90 outputs a drive signal from a CPU (Central Processing Unit) 91 to a three-phase amplifier (AMP) 95. The drive current Ti is supplied from the AMP 95 to the tilt motor 100. The tilt motor 100 directly applies a rotational force to the tilt shaft 22B by a three-phase sinusoidal drive current Ti. Together with the tilt shaft 22A supported by the machine base 51, the housing base 21 tilts in the tilt direction Ft upon receiving the rotational force in the rotational direction Rtilt. A tilt detection signal Tr is output from the position sensor 96 that has detected the position in the tilt direction Ft. Based on the information of the tilt detection signal Tr, the motor control circuit 90 determines whether or not the motor base 20 has reached the command position, and when it reaches the command position, stops the drive signal to the AMP 95. As described above, when the motor rotation command i including the tilt command or the like is input, the motor control circuit 90 outputs the drive current Ti that controls the tilt position of the motor base 20.

  FIG. 9 is a diagram showing cogging torque generated due to the stator core end portion of the motor stator. FIG. 11 is an explanatory diagram for explaining a state in which a plurality of motor stators cancels cogging torque generated due to the end portion of the stator core. As shown in FIG. 2, in the motor 1 according to the first embodiment, when the total number of motor stators including a stator core is Sn, the arc center of the motor stator 30A and the arc center of the motor stator 30B are expressed by the following formula (1 ) With an electrical angle represented by θe.

  θe = 360 ° / (2 × (Sn)) (1)

  In the first embodiment, since the motor stator 30A and the motor stator 30B are provided, the total number of motor stators including the stator core is two. For this reason, according to the above equation (1), the electrical angle represented by θe is 90 °. When the number of magnetic pairs is 48, when the electrical angle is converted to a mechanical angle, the mechanical angle is a value obtained by dividing the electrical angle by the number of magnetic pairs, that is, 90 ° / 48 = 1.875 °. On the other hand, the magnetic pole of the motor 1 is 96 poles, and one cycle of electrical angle is a mechanical angle, which is a value obtained by dividing 360 ° by the number of pole pairs 48, that is, 360 ° / 48 = 7.5 °. The motor stator 30A and the motor stator 30B satisfy an arbitrary value satisfying 7.5 ° × n + 1.875 ° (where n is a natural number) or 7.5 ° × n−1.875 ° (where n is a natural number). They can be arranged in a phase relationship. In the motor 1 according to the first embodiment, n = 24 is set so that the motor stators 30A and 30B are separately arranged in the vicinity of the tilt shaft 22A and the vicinity of the tilt shaft 22B. The motor stator 30B is spaced apart with a phase relationship of 125 ° (181.875 °).

  For this reason, the motor stator 30A and the motor stator 30B have cogging torque generated due to the stator core end portion generated in two cycles within one cycle of the electrical angle shown in FIG. The motor stator 30A and the motor stator 30B satisfy an arbitrary value satisfying 7.5 ° × n + 1.875 ° (where n is a natural number) or 7.5 ° × n−1.875 ° (where n is a natural number). By arranging them in phase relationship, the cogging torque 30A caused by the end portion of the stator core 31A and the cogging torque 30B caused by the end portion of the stator core 31B are offset, and the combined torque WS shown in FIG. 10 is reduced. Thus, a smooth rotation can be obtained.

  The magnet 42 and the first stator core 31A or the second stator core 31B are not opposed to each other in a plane (axial gap type) but are opposed to each other (radial gap type). And even if it uses a thin magnet, since the operating point of a magnet can be maintained, the inertia of the tilt direction Ft can be made small. In addition, the motor 1 directly applies a rotational force to the magnet without using an indirect transmission mechanism such as a gear. And a motor becomes what is called a direct drive motor, and can rotate a load body directly. Further, the motor can be positioned with high accuracy.

  Further, as shown in FIG. 6 described above, the magnet 42 has a rectangular shape when viewed from the outer diameter side toward the rotation center Zr. In the motor 1 according to the first embodiment, the magnet 42 does not have to be a magnet having a shape like a flat plate twisted, and can be easily molded and the cost of the motor can be reduced.

(Embodiment 2)
FIG. 11 is a plan view of the motor according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same component as what was demonstrated in Embodiment 1 and Embodiment 2 mentioned above, and the overlapping description is abbreviate | omitted.

  The motor 1B according to the second embodiment is a pseudo stator that does not energize the motor stator 30B. As described in the first embodiment, the motor stator 30B may have the same configuration as the motor stator 30A, and the excitation coil 32 may not be energized. As a result, the number of AMPs 92 in the motor 1A is smaller than that in the motor 1. The motor stator 30A and the motor stator 30B satisfy 7.5 ° × n + 1.875 ° (where n is a natural number) or 7.5 ° × n−1.875 ° (where n is a natural number). The cogging torque 30A generated due to the end portion of the stator core 31A and the cogging torque 30B generated due to the end portion of the stator core 31B are offset and the combined torque WS is reduced. Rotation can be obtained.

  As shown in FIG. 11, the motor stator 30B includes a second stator core 31B having the same shape as the first stator core 31A, but may be a pseudo stator that does not include the exciting coil 32. Even in such a motor stator 30B, the motor stator 30A and the motor stator 30B are 7.5 ° × n + 1.875 ° (where n is a natural number) or 7.5 ° × n−1.875 °. (Where n is a natural number), the cogging torque 30A caused by the end portion of the stator core 31A and the cogging torque 30B caused by the end portion of the stator core 31B are offset by arranging them in an arbitrary phase relationship. By reducing the combined torque WS, smooth rotation can be obtained. In the motor 1A according to the second embodiment, n = 24 is set so that the motor stators 30A and 30B are arranged separately in the vicinity of the tilt shaft 22A and the vicinity of the tilt shaft 22B, and the mechanical angle from the motor stator 30A is, for example, 178. The motor stator 30B is spaced apart with a phase relationship of 125 ° (181.875 °).

  As described above, in the motor stator 30B, the second stator core 31B having the same shape as the first stator core 31A included in the motor stator 30A is arranged as a pseudo stator. The stator core according to the second embodiment is not limited to the shape of the second stator core 31B having the same shape as the first stator core 31A, and is appropriately changed for reasons such as the overall shape. For example, if the strong magnetic force generated between the motor rotor 10 and the pseudo-stator and the strong cogging torque generated in two cycles within one electrical angle cycle due to the teeth 31T can be offset, the arc shape is simple. Also good.

(Embodiment 3)
FIG. 12 is a plan view of the motor according to the third embodiment. FIG. 13 is an explanatory diagram for explaining a state in which a plurality of motor stators cancels cogging torque generated due to the end portion of the stator core. In addition, the same code | symbol is attached | subjected to the same component as what was demonstrated in Embodiment 1 mentioned above, and the overlapping description is abbreviate | omitted.

  The motor 1B according to the third embodiment includes motor stators 30A, 30B, and 30C, a motor rotor 10 that is rotatably arranged with respect to the motor stators 30A, 30B, and 30C, and a motor base that fixes the motor stators 30A, 30B, and 30C. 20. The plurality of motor stators 30A, 30B, and 30C include a plurality of stator cores 31A, 31B, and 31C including the excitation coils 32, and the three motor stators 30A, 30B, and 30C are provided by three AMPs 92 that supply power to the excitation coils 32, respectively. Each of 30C is driven by a different AMP92. For this reason, since the motor 1 can flow a motor current according to the energization timing of each of the motor stators 30A, 30B, and 30C even if there is a deviation in electrical angle between the plurality of motor stators 30A, 30B, and 30C, smooth rotation Can be obtained. As shown in FIG. 12, when Sn is the total number of motor stators 30A, 30B, and 30C, Sn = 3, and the phases are shifted by the electrical angle represented by θe in the above equation (1). Note that θe 'is also derived in (1) above.

  In the third embodiment, since Sn is 3, the electrical angles represented by θe and θe ′ are 60 °. When the number of magnetic pairs is 48, when the electrical angle is converted into a mechanical angle, the mechanical angle is a value obtained by dividing the electrical angle by the number of magnetic pairs, that is, 60 ° / 48 = 1.25 °. On the other hand, the magnetic pole of the motor 1 is 96 poles, and one cycle of electrical angle is a mechanical angle, which is a value obtained by dividing 360 ° by the number of pole pairs 48, that is, 360 ° / 48 = 7.5 °. Each of motor stators 30A, 30B, and 30C satisfies 7.5 ° × n + 1.25 ° (where n is a natural number) or 7.5 ° × n−1.25 ° (where n is a natural number). Can be arranged in a phase relationship. In the motor 1B according to the third embodiment, the motor stators 30A and 30B are disposed in the vicinity of the tilt shaft 22B, and the motor stator 30C is disposed in the vicinity of the tilt shaft 22A. In obtaining the electrical angle θe, the motor 1B according to the third embodiment sets, for example, n = 22, and the motor stator 30A is arranged away from the motor stator 30C in a phase relationship of 163.75 ° in mechanical angle. In the motor 1B according to the third embodiment, when obtaining the electrical angle θe ′, n = 5 and the motor stator 30B is arranged away from the motor stator 30A in a phase relationship of 36.25 ° in mechanical angle.

Therefore, as shown in FIG. 13, in the motor 1B according to the third embodiment, the motor stator 30A, 30B, 30 C What happened is, 7.5 ° × n + 1.25 ° ( where, n is a natural number) or 7. The cogging torque 30A generated due to the end of the stator core of the motor stator 30A and the motor stator 30B are arranged by an arbitrary phase relationship satisfying 5 ° × n−1.25 ° (where n is a natural number). The cogging torque 30B generated due to the stator core end and the cogging torque 30C generated due to the stator core end of the motor stator 30C cancel each other, and the combined torque WS is reduced, thereby obtaining a smooth rotation. Can do.

(Embodiment 4)
FIG. 14 is a plan view of the motor according to the fourth embodiment. FIG. 15 is an explanatory diagram for explaining a state in which a plurality of motor stators cancels cogging torque caused by the end portion of the stator core. In addition, the same code | symbol is attached | subjected to the same component as what was demonstrated in Embodiment 1 mentioned above, and the overlapping description is abbreviate | omitted.

  The motor 1C according to the fourth embodiment includes motor stators 30A, 30A, 30B, and 30B, a motor rotor 10 that is rotatably arranged with respect to the motor stators 30A, 30A, 30B, and 30B, and motor stators 30A, 30A, 30B, and And a motor base 20 for fixing 30B. The magnetic pole of the motor 1C has 96 poles, and one cycle of electrical angle is a mechanical angle, which is a value obtained by dividing 360 ° by the number of pole pairs 48, that is, 360 ° / 48 = 7.5 °. Each of the motor stators 30A and 30A can be arranged with an arbitrary phase relationship satisfying 7.5 ° × n (where n is a natural number) so as to have a mechanical angle of θm. Further, each of the motor stators 30B and 30B can be arranged in an arbitrary phase relationship satisfying 7.5 ° × n (where n is a natural number) so as to have a mechanical angle of θm. The motor 1C according to the fourth embodiment satisfies θm = 180 °, for example.

  For this reason, since the motor stators 30A and 30A are arranged at the same electrical angle, they can be driven by the same AMP92. Further, since the motor stators 30B and 30B are arranged at the same electrical angle, they can be driven by the same AMP92. As described above, the plurality of motor stators 30A, 30A, 30B, and 30B include a plurality of stator cores 31A and 31B including the excitation coils 31, and are driven by a plurality of AMPs 92 that supply electric power to the respective excitation 31 coils. Of the plurality of motor stators 30A, 30A, 30B and 30B, the two motor stators 30A and 30A are driven by an AMP 92 different from the motor stators 30B and 30B. Since the motor stators 30A and 30A have the same electrical angle and the motor stators 30B and 30B have the same electrical angle, when the total number of motor stators is Sn, it corresponds to Sn = 2, and the above formula (1) The phase is shifted by the electrical angle represented by θe. For this reason, the motor 1 can flow a motor current according to the energization timing of each of the motor stators 30A and 30B even if there is a deviation of the electrical angle between the plurality of motor stators 30A and 30B, so that smooth rotation can be obtained. it can.

  In the fourth embodiment, Sn is 2, and the electrical angle represented by θe is 90 °. When the number of magnetic pairs is 48, when the electrical angle is converted to a mechanical angle, the mechanical angle is a value obtained by dividing the electrical angle by the number of magnetic pairs, that is, 90 ° / 48 = 1.875 °. On the other hand, the magnetic pole of the motor 1 is 96 poles, and one cycle of electrical angle is a mechanical angle, which is a value obtained by dividing 360 ° by the number of pole pairs 48, that is, 360 ° / 48 = 7.5 °. The motor stator 30A and the motor stator 30B satisfy an arbitrary value satisfying 7.5 ° × n + 1.875 ° (where n is a natural number) or 7.5 ° × n−1.875 ° (where n is a natural number). They can be arranged in a phase relationship. In the motor 1C according to the fourth embodiment, in the motor 1C according to the fourth embodiment, the motor stators 30A and 30B are disposed in the vicinity of the tilt shaft 22B, and the motor stator 30C is disposed in the vicinity of the tilt shaft 22A. In determining the electrical angle θe, the motor 1C according to the third embodiment sets, for example, n = 19, and the motor stator 30A is disposed away from the motor stator 30B in a phase relationship of 144.375 ° in mechanical angle.

  For this reason, the motor stator 30A and the motor stator 30B have cogging torque generated due to the stator core end portion generated in two cycles within one cycle of the electrical angle shown in FIG. The motor stator 30A and the motor stator 30B satisfy an arbitrary value satisfying 7.5 ° × n + 1.875 ° (where n is a natural number) or 7.5 ° × n−1.875 ° (where n is a natural number). By arranging in phase relation, the cogging torque 30A generated due to the end portion of the stator core 31A and the cogging torque 30B generated due to the end portion of the stator core 31B cancel each other and the combined torque WS is reduced. Can be obtained.

  In addition, the motor 1C according to the fourth embodiment has one motor stator 30A and one motor stator B arranged so as to be biased in the vicinity of the tilt shaft 22A and the other in the vicinity of the tilt shaft 22B. The motor stator 30A and the other motor stator B are arranged so as to be biased. As described above, the motor base 20 includes the tilt shaft 22A and the tilt shaft 22B extending in opposite directions so as to be parallel to the tilt axis Axt, and the plurality of motor stators 30A and 30B are tilted in the vicinity of the tilt shaft 22A. They are arranged separately from the vicinity of the shaft 22B. For this reason, in the motor base 20, the protrusion length from the axial center of the tilt axis Axt is suppressed. Further, by reducing the mass of the motor stator 30A and the motor stator 30B applied to the portion of the motor base 20 that is away from the axis of the tilt axis Axt, the motor 1 can have the inertia in the tilt direction Ft shown in FIG. Can be suppressed.

(Application example)
FIG. 20 is an explanatory diagram for explaining an optical apparatus to which the motor of this embodiment is applied. The motors 1, 1 </ b> A, 1 </ b> B, and 1 </ b> C according to the first to fifth embodiments can be applied to an optical device called a three-dimensional scanner or a medical device described in Patent Literature 2. For example, the three-dimensional scanner 200 is an optical device that measures the three-dimensional shape of the object to be measured, and includes the motor 1 according to the first embodiment, the machine base 51, the lifting device 52A of the machine base 51, and the tilting device described above. The motor 100, the raising / lowering device 52B of the tilting motor 100, and the optical head 102 that rotates together with the motor rotor 10 of the motor 1 described above are provided. Thus, when the motor 1 is supported by the tilt shaft, the protrusion length of the tilt shaft from the axis can be suppressed, and the inertia in the tilt direction, that is, the rotation direction Rtilt described above can be suppressed.

1, 1A, 1B, 1C Motor 10 Motor rotor 10H Hollow hole 11 Hollow shaft 14 Bearing device 20 Motor base 21 Housing base 21f Surface 22A First tilt shaft 22B Second tilt shaft 30A Motor stator 30B Motor stator 31A First stator core 31B Second Stator core 31T Teeth 32 Excitation coil 41 Rotor yoke 42 Magnet 51 Machine base 51f Surface 90 Motor control circuit G Magnetic gap Zr Rotation center 100 Tilt motor Axt Tilt shaft

Claims (7)

A hollow annular hollow shaft, and a motor rotor comprising a plurality of magnets arranged in an outer periphery and a circumferential direction of the hollow shaft;
A motor base that penetrates the hollow shaft , surrounds a radially outer side of the motor rotor, and is swingable by a tilt shaft;
A bearing that rotatably supports the hollow shaft on the inner wall of the motor base;
A plurality of motor stators having a stator core, which are attached to the motor base and face a part of the number of poles of the plurality of magnets via a magnetic gap;
The plurality of motor stators are arranged at different positions in the circumferential direction of the motor rotor,
The circumferential length of all the motor stators is smaller than the circumferential length of the motor rotor ,
When the total number of the motor stators is Sn, among the plurality of motor stators , at least the first motor stator and the second motor stator are arranged with an electrical angle separation of θe of the following formula (1),
The motor base includes a first tilt shaft and a second tilt shaft extending in opposite directions to be parallel to the tilt axis,
The first motor stator and the second motor stator are arranged separately in the vicinity of the first tilt shaft and in the vicinity of the second tilt shaft, and when viewed from the direction along the rotation center of the motor rotor, the tilt shaft A motor that is not line-symmetrical with respect to a line that passes through the center of rotation and that is perpendicular to the center of the motor rotor and that is shifted in the circumferential direction of the motor rotor .
θe = 360 ° / (2 × (Sn)) (1) The first motor stator and the second motor stator are each wound around an arc-shaped back yoke, a plurality of teeth projecting toward the inner diameter side of the back yoke, and the U-phase, V the motor according to claim 1, further comprising an excitation coil corresponding to the phase and W-phase. The first motor stator is wound around each of the teeth, an arc-shaped back yoke, a plurality of teeth protruding toward the inner diameter side of the back yoke, and corresponds to the U phase, the V phase, and the W phase. The excitation coil
The second motor stator includes an arcuate back yoke, a plurality of teeth projecting toward the inner diameter side of the back yoke, and an excitation coil that does not energize or is energized around each of the teeth. the motor according to no pseudo Sutetako Hair to including claim 1. The plurality of motor stators includes a plurality of stator cores including excitation coils, and is driven by an amplifier that supplies power to the excitation coils.
Includes a plurality of amplifiers for supplying power to the front Ki励 magnetic coil,
Wherein the plurality of excitation coils of the first motor stator of the motor stator, the second motor stays capacitor motor according to 請 Motomeko 1 or 2 electrodes to the excitation coil Ru is driven by an amplifier with different amplifier supplies the. The plurality of motor stators includes a third motor stator,
The first motor stator is disposed in the vicinity of the first tilt shaft,
The second motor stator and the third motor stator, a motor as set forth 請 Motomeko 1 is disposed near the second tilt shaft in any one of 4. Before SL on the outer circumference of the hollow shaft is exposed, the motor according to any one of 5 from the 請 Motomeko first magnet are located. The magnet motor according to any one of the shapes tried toward the center of rotation from the outer diameter side from 請 Motomeko 1 Ru rectangular der 6.

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