JP2024149931A - Motor - Google Patents

Abstract

A motor that suppresses vibration is provided.
[Solution] The motor 1 includes a rotor, a stator 3, and a housing 2. The rotor includes a rotating shaft 41. The housing 2 houses or holds the rotor and the stator 3. The housing 2 includes a bracket 22 and a frame 21. The bracket 22 rotatably holds a first end of the rotating shaft 41. The frame 21 rotatably holds a second end of the rotating shaft 41. The bracket 22 has a base 221 and a flexible portion 63. The flexible portion 63 protrudes from an end 220 of the base 221 and is inserted into the frame 21 from an opening 210 of the frame 21. The flexible portion 63 has one of a protrusion 61 and a recess 62, and the frame 21 has the other of the recess 62 and the protrusion 61. The bracket 22 is fixed to the frame 21 in a manner that the bracket 22 is inserted into the opening 210 in the frame 21 by fitting the protrusion 61 into the recess 62.
[Selected figure] Figure 2

Description

This disclosure relates generally to motors, and more particularly to motors having brackets.

Patent Document 1 discloses a brushless motor. This brushless motor has an end bracket that holds and rotates a rotor magnet and other components via a ball bearing and a rotating shaft. The end bracket is made of synthetic resin made of engineering plastic material. A Hall element mounting hole is formed in part of the end bracket to precisely mount a Hall element for detecting the magnetic pole position.

Japanese Patent Application Publication No. 8-23666

In motors that have a bracket, rotor vibrations can be transmitted to the bracket, causing the bracket to vibrate.

This disclosure has been made in consideration of the above problems, and aims to provide a motor that suppresses vibration of the bracket.

A motor according to one aspect of the present disclosure includes a rotor, a stator, and a housing. The rotor has an axis as its center of rotation and includes a rotating shaft extending in the direction in which the axis extends. The stator is positioned opposite the rotor and supplies a magnetic force that rotates the rotor. The housing contains or holds the rotor and the stator.

The housing includes a bracket and a frame. The bracket holds a first end of the rotating shaft for rotation. The frame holds a second end of the rotating shaft for rotation. The frame has an open opening. The bracket has a base and a flexible portion. The flexible portion protrudes from an end of the base and is inserted into the frame through the opening in the frame. The flexible portion has one of a protrusion and a recess. The frame has the other of the recess and the protrusion. The bracket is fixed to the frame in a manner that the bracket is inserted into the opening in the frame by fitting the protrusion into the recess.

This disclosure provides a motor that suppresses vibration of the bracket.

FIG. 1 is an external view of a motor according to an embodiment. FIG. 2 is a perspective view of the motor with the frame removed. FIG. 3 is an external view of the bracket of the motor. FIG. 4 is a top view of the motor with the bracket removed. FIG. 5 is a cross-sectional view of the motor. FIG. 6 is an external view of a motor according to a first modified example of the embodiment. FIG. 7 is a perspective view of the motor with the frame removed. FIG. 8 is an external view of the bracket of the motor. FIG. 9 is a cross-sectional view of the motor. Fig. 10A is an enlarged view of a Z1 region in Fig. 9 in the motor of the above embodiment, Fig. 10B is a view for explaining a fitting portion of a motor according to a second modified example of the embodiment. FIG. 11 is an external view of a bracket of a motor according to a third modified example of the embodiment.

The embodiments and modifications described below are merely examples of the present disclosure, and the present disclosure is not limited to the embodiments and modifications. Other than these embodiments and modifications, various modifications may be made according to the design, etc., as long as they do not deviate from the technical concept of the present disclosure.

(Embodiment)
Hereinafter, a motor 1 according to this embodiment will be described with reference to FIGS.

(1) Overview Fig. 1 is an external view of a motor 1 according to one embodiment. Fig. 2 is a perspective view of the motor 1 according to one embodiment with a frame 21 removed. Fig. 3 is an external view of a bracket 22 of the motor 1 according to one embodiment. Fig. 4 is a top view of the motor 1 according to one embodiment with the bracket 22 removed. Fig. 5 is a cross-sectional view of the motor 1 according to one embodiment.

The motor 1 of this embodiment shown in FIG. 1 is, for example, a motor used in an automobile brake. However, the motor 1 is not limited to an in-vehicle motor, and may be, for example, a motor applied to electrical equipment such as home appliances.

The motor 1 of this embodiment includes a rotor 4, a stator 3, and a housing 2, as shown in Figures 2 and 5.

The rotor 4 includes a rotating shaft 41. The rotating shaft 41 rotates around the axis C1 and extends in the direction in which the axis C1 extends. The rotor 4 rotates due to a magnetic force generated by the stator 3, which will be described later. The stator 3 is positioned opposite the rotor 4. The stator 3 supplies a magnetic force that rotates the rotor 4. The housing 2 accommodates the rotor 4 and the stator 3. The housing 2 holds the rotor 4 and the stator 3 directly or indirectly.

The housing 2 includes a bracket 22 that rotatably holds the first end of the rotating shaft 41, and a frame 21 that rotatably holds the second end of the rotating shaft 41. The frame 21 has an open opening 210. The bracket 22 has a base 221 and a flexible portion 63. The flexible portion 63 protrudes from an end portion 220 of the base 221 and is inserted into the frame 21 through the open opening 210 in the frame 21. The flexible portion 63 has one of a protrusion 61 and a recess 62, and the frame 21 has the other of the recess 62 and the protrusion 61. The bracket 22 is fixed to the frame 21 in a manner that the bracket 22 is inserted into the open opening 210 in the frame 21 by fitting the protrusion 61 into the recess 62.

The rotating shaft 41 rotates around the axis C1 due to the rotating rotor 4, outputting rotational power.

In other words, the frame 21 and bracket 22 in the housing 2 are fixed together by the mating portion 6 formed by mating the protrusion 61 and recess 62.

Conventionally, the vibration of the motor is transmitted to the bracket, and the bracket vibrates at the motor's natural frequency, which can cause noise. For example, in fields such as in-vehicle applications, suppressing the vibration of the bracket is important for making the ride more comfortable for passengers. In particular, in in-vehicle applications with a wide operating temperature range, for example, from -40°C to 120°C, it is not easy to hold the frame and bracket together by press-fitting alone. Furthermore, if the frame and bracket are fixed together by press-fitting alone, vibrations of the resonant frequency are more likely to be transmitted to the bracket, which can cause the vibration to increase. The resonant frequency here refers to a frequency at which the vibration is amplified and strong shaking occurs when the same frequency as the natural frequency of an object (for example, motor 1) is applied to the object (for example, motor 1). In other words, when the motor 1 is subjected to vibrations of the same frequency as the natural frequency of the motor 1, the vibration increases.

According to the configuration of the motor 1 of this embodiment, the frame 21 has one of the convex portion 61 and the concave portion 62, and the bracket 22 has the other of the concave portion 62 and the convex portion 61, and the bracket 22 is fixed to the frame 21 by fitting the convex portion 61 and the concave portion 62. Therefore, according to the configuration of the motor 1 of this embodiment, vibration of the bracket 22 can be suppressed.

(2) Configuration The motor 1 according to this embodiment will be described in detail below.

As shown in Figures 1, 4, and 5, the motor 1 includes a housing 2, a stator 3, a rotor 4, a ball bearing 7, a number of jumper wires 44, and a number of connection terminals 45.

(2-1) Rotor As shown in Fig. 5, the rotor 4 includes a cylindrical rotor core 40, a rotating shaft 41, and a plurality of (ten in this embodiment) permanent magnets 46. The plurality of permanent magnets 46 are attached to the surface of the rotor core 40. The plurality of permanent magnets 46 are arranged so as to cover the side surface of the cylindrical rotor core 40. The rotor core 40 may be cylindrical, or may be cylindrical in shape with a polygonal cross section intersecting the direction in which the axis C1 extends.

The rotor core 40 includes multiple steel plates. The rotor core 40 is formed by stacking multiple steel plates in the thickness direction (the direction in which the axis C1 extends). Each steel plate is made of a magnetic material (e.g., silicon steel plate).

In other words, the rotor 4 has multiple permanent magnets 46, and rotates with the magnetic field generated by the multiple permanent magnets 46 and the magnetic field generated by current flowing through the coils 42 of the stator 3, transmitting the generated torque to the rotating shaft 41. The material of the rotor core 40 is, for example, iron. More specifically, the rotor core 40 is made of, for example, silicon steel mixed with silicon, permalloy, or ferrite. Also, since the rotor core 40 requires high strength to transmit the generated torque to the rotating shaft 41, alloys of iron, nickel, copper, carbon, etc. may be used.

Each of the multiple (10 in this embodiment) permanent magnets 46 is, for example, a neodymium magnet. The magnetic poles of the multiple permanent magnets 46, that is, the north poles and south poles, are arranged alternately in the circumferential direction A1 of the rotor core 40. In other words, the north poles and south poles of the magnets are arranged alternately on the outer periphery of the multiple permanent magnets 46 in the circumferential direction.

A rotating shaft 41 is held inside the rotor core 40. The rotating shaft 41 is held inside the rotor core 40 with the rotor core 40 and the axis C1 being coaxial. As shown in FIG. 5, the rotor core 40 has an axial hole through which the rotating shaft 41 passes. The rotor core 40 can rotate with the rotating shaft 41 relative to the stator 3, and rotates due to a magnetic field generated by current flowing through multiple coils 42 of the stator 3.

(2-2) Stator As shown in FIGS. 4 and 5, the stator 3 includes a stator core 30, a plurality of teeth 43, a plurality of coils 42 (12 in this embodiment), and an insulator 5.

As shown in Figures 2 and 5, the stator core 30 is formed by stacking multiple steel plates in the thickness direction (the direction in which the axis C1 extends). Each steel plate is made of a magnetic material, such as a silicon steel plate.

Each of the teeth 43 protrudes from the inner circumferential surface of the stator core 30 toward the axis C1. The direction from the inner circumferential surface of the stator core 30 toward the axis C1 is a direction that intersects with the direction in which the axis C1 extends, for example, a direction that is perpendicular to the direction in which the axis C1 extends.

A corresponding coil 42 is formed around each of the multiple teeth 43 by winding a conductor around the electrically insulating insulator 5. The multiple teeth 43 may be configured to be separable. By allowing the multiple teeth 43 to be separated, the coil 42 is formed in a separated state, and the stator 3 is formed later. This improves the space factor of the coil 42, reduces copper loss, and improves the efficiency of the motor 1. Here, the space factor refers to the area occupied by the copper wire relative to the part where the copper wire is wound.

The insulator 5 is an electrically insulating member. For example, PPS (Poly Phenylene Sulfide) or PBT (Poly Butylene Terephthalate) can be used for the insulator 5. For example, for applications requiring high heat resistance or for vehicle mounting, a resin such as PPS containing approximately 30 to 50% by weight of a filler such as glass fiber is used. For applications not requiring high heat resistance, the insulator 5 may be made of a resin such as PBT containing approximately 15 to 30% by weight of a filler such as glass fiber. In this embodiment, the insulator 5 is configured to be separable into two in the direction of the axis C1. The coil 42 is formed by winding a conductor around the teeth 43 covered by the insulator 5. In other words, the insulator 5 is formed with a coil 42 whose winding axis is in a direction (radial direction) that intersects with the direction in which the axis C1 of the rotating shaft 41 extends.

(2-3) Housing The housing 2 includes a frame 21 and a bracket 22, and each of the frame 21 and the bracket 22 is made of metal or resin. That is, the frame 21 is made of metal or resin, and the bracket 22 is made of metal or resin. For this reason, there are four combinations of materials for the frame 21 and the bracket 22: both are metal, both are resin, the frame 21 is metal and the bracket 22 is resin, and the frame 21 is resin and the bracket 22 is metal. In this embodiment, of the above combinations, a case where the frame 21 is made of metal and the bracket 22 is made of resin will be described. The metal is, for example, iron. The resin is, for example, engineering plastic.

When metal is used, it has high strength and excellent heat dissipation properties, so when used for the frame 21, good strength and heat dissipation properties can be expected. On the other hand, when resin is used, there is a high degree of freedom in shape, it is lightweight, and low cost. For example, when resin is used for the bracket 22, the resonance frequency of the motor 1 described above changes, so vibration of the bracket 22 can be suppressed.

As described above, the housing 2 includes a metal frame 21 and a resin bracket 22. As shown in FIG. 1, the metal frame 21 has a cylindrical shape. The frame 21 has an open opening 210 at one end. As shown in FIG. 5, the frame 21 has a circular protrusion 212 at the other end 211 opposite to the end where the opening 210 is located. The frame 21 has the protrusion 212 at the other end 211 opposite to the opening 210, so that the ball bearing 7 can be accommodated in the space 213 formed by the protrusion 212. The ball bearing 7 holds the rotating shaft 41 rotatably. The ball bearing 7 has an inner ring fixed to the rotating shaft 41 and an outer ring fixed to the frame 21 of the motor 1. The inner ring of the ball bearing 7 rotates together with the rotating shaft 41 as the rotor 4 rotates, while the balls held in the retainer of the ball bearing 7 are sealed with lubricating oil, allowing the outer ring of the ball bearing 7 to hold the rotating shaft 41 while allowing smooth rotation. The main materials for the ball bearing 7 are, for example, high carbon chromium steel, medium carbon steel, and silicon nitride ceramics.

In this embodiment, the rotating shaft 41 is a solid shaft, but this is not intended to be limited to a solid shaft. The rotating shaft 41 is held inside the rotor core 40 with the rotor core 40 and the axis C1 being coaxial. The axis C1 is a virtual axis and corresponds to the center of rotation of the motor 1.

As shown in FIG. 2, the frame 21 of this embodiment has a half-punched portion 66 (protruding portion 61) on the inner peripheral surface of the frame 21 that protrudes toward the rotation shaft 41. The half-punched portion 66 is a portion that is half-punched in the punching process, rather than being completely punched out with a dowel (also called a half pierce). In this embodiment, the half-punched portion 66 forms the fitting portion 6 by fitting with a recessed portion 62 of the bracket 22, which will be described later. The half-punched portions 66 are located on a circumference perpendicular to the axis C1 (virtual axis) of the frame 21, and there are eight of them in this embodiment. Note that FIG. 2 shows only six half-punched portions 66 (three of which are shown on the back side).

The eight half-punched portions 66 are arranged in four pairs of two each. The half-punched portions 66 forming one pair are formed in symmetrical positions across the axis C1. For example, as shown in FIG. 2, the convex portion 611 is paired with the convex portion 615 across the axis C1, and the convex portion 612 is paired with the convex portion 614 across the axis C1. While the four pairs of half-punched portions 66 in this embodiment are each in a symmetrical position, it is not essential that the frame 21 be evenly divided on the circumference perpendicular to the axis C1.

In this embodiment, the eight half-punched portions 66 do not divide the circumference of the frame 21 evenly. Specifically, as shown in FIG. 2, the convex portions 611 and 612, and the convex portions 614 and 615 are each provided at a circumferential distance L1. On the other hand, the convex portions 611 and 613, and the convex portions 615 and 616 are each provided at a circumferential distance L2. In this embodiment, the distances L1 and L2 are not equal, so the eight convex portions 61 are not evenly provided on the circumference of the frame 21. The eight half-punched portions 66 may equally divide the circumference of the frame 21 perpendicular to the axis C1. That is, in the above example, the distances L1 and L2 may be equal.

The resin bracket 22 has a circular base 221 as shown in FIG. 3. The circular base 221 has a circular hole 222 concentric with the base 221 in the center as shown in FIG. 3. The base 221 also has an outlet hole 223 for outletting the connection terminal 45. As shown in FIG. 3, the bracket 22 has a flexure 63. One or more flexures 63 are formed on the bracket 22. The flexure 63 flexes when the bracket 22 is inserted into the frame 21. It is preferable that the number of flexures 63 is three or more, taking into consideration the suppression of vibration and balance. However, the number of flexures 63 may be one or two as long as the motor 1 is centered. The number of flexures 63 may be four or more. In this embodiment, the number of flexures 63 is eight. Note that FIG. 3 illustrates three of the eight flexures 63.

In this embodiment, multiple (eight in this embodiment) flexures 63 and multiple (eight in this embodiment) positioning portions 64, which will be described later, protrude from the end portion 220 in the radial direction A2 of the base 221 included in the bracket 22 toward the ball bearing 7 (downward in FIG. 3) in the direction in which the axis C1 extends.

The flexure 63 is accommodated in the frame 21 while flexing when the bracket 22 is inserted into the frame 21. In this embodiment, the frame 21 has a convex portion 61, and the flexure 63 of the bracket 22 has a concave portion 62. That is, in this embodiment, the frame 21 has a convex portion 61 that protrudes from the inner surface of the frame 21 toward the rotation shaft 41, and the flexure 63 of the bracket 22 has a concave portion 62 and is movable in a direction perpendicular to the rotation shaft 41. In this embodiment, the term "movable" corresponds to "flexing." When the bracket 22 is inserted into the frame 21, the flexure 63 flexes in the direction of the rotation shaft 41 (inside the bracket 22), but when the convex portion 61 and the concave portion 62 engage, the deformation that occurred during insertion is elastically restored, and the flexure is somewhat eliminated.

In this embodiment, as shown in FIG. 3, the bracket 22 further has one or more positioning portions 64. Here, as an example, the bracket 22 has eight positioning portions 64. Note that FIG. 3 illustrates four of the eight positioning portions 64. The multiple bending portions 63 are provided independently of the multiple positioning portions 64 in the circumferential direction A1 of the bracket 22 by multiple slits 65 formed in the bracket 22. As shown in FIG. 3, the multiple positioning portions 64 are composed of two types, a first positioning portion 64A and a second positioning portion 64B. Each positioning portion 64 has a peripheral wall (peripheral wall 69A or peripheral wall 69B) and one or two positioning pieces 641.

The number of first positioning portions 64A is, for example, four. Each first positioning portion 64A has a peripheral wall 69A and one positioning piece 641, and is adjacent to two flexible portions 63 via two slits 65 on both sides in the circumferential direction A1.

On the other hand, the number of the second positioning portions 64B is, for example, four. Each second positioning portion 64B has a peripheral wall 69B and two positioning pieces 641. Each second positioning portion 64B is adjacent to two flexures 63 via two slits 65 on both sides in the circumferential direction A1. Twelve positioning pieces 641 for positioning are formed in the circumferential direction A1 of the bracket 22. Due to the provision of the slits 65, the flexures 63, the first positioning portion 64A, and the second positioning portion 64B are provided independently of each other in the circumferential direction A1 of the bracket 22. In addition, the length from the end 220 of the bracket 22 to the tip of the peripheral wall (peripheral wall 69A or 69B) and the length from the end 220 of the bracket 22 to the tip of the flexure 63 are approximately the same (that is, the protruding amounts of each are approximately the same). The positioning portion 64 is longer than the flexure 63 by the amount of the positioning pieces 641. In this embodiment, the number of positioning pieces 641 is 12, but all of the positioning pieces 641 have the same shape. The flexible portions 63 and the positioning portions 64 are independent of each other in the circumferential direction A1, which makes it difficult for vibrations of the motor 1 to be transmitted to the bracket 22. In other words, the vibrations are not received around the entire circumference of the bracket 22, but are received at the mating portions 6 (eight in this embodiment) between the convex portions 61 and the concave portions 62. This means that the vibrations are only partially transmitted to the bracket 22, and the vibrations of the bracket 22 can be suppressed.

The positioning portion 64 protruding from the end 220 of the base 221 of the bracket 22 has a length that protrudes from the end 220 of the bracket 22 longer than the length that the flexure 63 protrudes from the end 220 of the base 221 of the bracket 22. That is, in this embodiment, the protruding length of the positioning portion 64 is longer than the protruding length of the flexure 63 when viewed from the base 221. In this embodiment, the positioning portion 64 has 12 positioning pieces 641, but this is not intended to be limited to 12. The positioning portion 64 indirectly determines the position of the bracket 22 relative to the frame 21 by the positioning pieces 641 coming into contact with the teeth 43.

The multiple flexures 63 are provided in multiple pairs (four in this embodiment, a total of eight locations) symmetrically arranged on either side of the axis C1. Each pair of flexures 63 is provided symmetrically in the circumferential direction A1 of the bracket 22, taking into consideration the balance of retention between the frame 21 and the bracket 22. The multiple flexures 63 do not have to be evenly arranged in the circumferential direction A1 of the bracket 22, for example, due to the influence of ribs or the like provided inside the bracket 22. Note that the multiple flexures 63 may be evenly arranged in the circumferential direction A1 of the bracket 22.

As described above, the flexure 63 has a recess 62 that fits with the protrusion 61 included in the frame 21. In this embodiment, the recess 62 fits with the protrusion 61 (half-punched portion 66) included in the frame 21 to form the fitting portion 6. Each flexure 63 is independent from the other flexures 63 and the multiple positioning portions 64 in the circumferential direction A1 of the bracket 22 by providing a slit 65. The frame 21 and the bracket 22 are fitted with multiple (eight in this embodiment) fitting portions 6. That is, in this embodiment, the frame 21 and the bracket 22 are connected through eight fitting portions 6. Therefore, the area that receives vibration is smaller than when the frame 21 and the bracket 22 are fixed by press-fitting, so vibration is less likely to be transmitted to the bracket 22, and as a result, vibration of the bracket 22 can be suppressed.

The flexible portion 63 is accommodated in the frame 21 while being flexible when inserted into the frame 21 through the opening 210 of the frame 21. Specifically, the flexible portion 63 is flexible when the bracket 22 is inserted into the frame 21, and when the protruding portion 61 and the recessed portion 62 are fitted together, the flexibility is somewhat eliminated by elastic recovery.

The multiple positioning portions 64 are arranged to avoid the insulator 5 so that the positioning pieces 641, which are the tips of each of the multiple positioning portions 64, come into contact with the positions of the teeth 43. As described above, the insulator 5 has a protrusion 51 that physically protects and electrically insulates the jumper wire 44. The positioning portions 64 are arranged to avoid the protrusion 51. In other words, the position of the positioning portion 64 in the circumferential direction A1 on the bracket 22 does not overlap with the protrusion 51 of the insulator 5 when viewed from the direction of the axis C1. That is, when viewed from the direction of the axis C1, the protrusion 51 and the positioning portions 64 are arranged in different positions.

On the other hand, the position of the flexure 63 in the circumferential direction A1 on the bracket 22 overlaps with the protrusion 51 of the insulator 5 when viewed from the direction of the axis C1. In other words, it can be said that the flexure 63 and the protrusion 51 are in the same position in the direction of the axis C1 of the frame 21. The flexure 63 protrudes less from the end 220 of the bracket 22 than the positioning portion 64, and although the flexure 63 and the protrusion 51 are in the same position in the direction of the axis C1, they do not interfere with each other.

In this embodiment, the shape of the recess 62 is rectangular when viewed from the radial direction (A2) of the bracket 22, as shown in FIG. 3. In other words, it is formed to match the shape of the protrusion 61 included in the frame 21.

(2-4) Details of Coil Wiring in Stator Next, details of the wiring of the coils 42 in the stator 3 will be described with reference to FIGS. 4 and 5. FIG.

As shown in FIG. 4, the multiple coils 42 include multiple phase coils U1-U4, V1-V4, and W1-W4 (three phases, U-phase, V-phase, and W-phase, in this embodiment). The multiple phase coils U1-U4, V1-V4, and W1-W4 are provided in a one-to-one relationship on the multiple teeth 43.

Twelve coils 42 are provided corresponding to the twelve teeth 43. The coils 42 of the same phase are connected to each other via jumper wires 44 and connected to the connection terminal 45. The jumper wire 44 is an electric wire that connects the coils 42 of the same phase to each other, and has one end connected to a plurality of coils 42 (four in this embodiment) and the other end connected to the connection terminal 45 (see Figures 1, 2, and 5). The jumper wire 44 of each phase is connected to the U-phase connection portion 441, the V-phase connection portion 442, and the W-phase connection portion 443. Specifically, among the multiple coils 42, the coils U1 to U4 constituting the U-phase are connected to the U-phase connection terminal 451. Furthermore, among the multiple coils 42, the coils V1 to V4 constituting the V-phase are connected to the V-phase connection terminal 452. Furthermore, among the multiple coils 42, the coils W1 to W4 constituting the W-phase are connected to the W-phase connection terminal 453. The U-phase connection part 441, the V-phase connection part 442, and the W-phase connection part 443, and the U-phase connection terminal 451, the V-phase connection terminal 452, and the W-phase connection terminal 453 are integrally molded from resin.

In this embodiment, as shown in FIG. 4, the multiple coils 42 are arranged in the following order in a counterclockwise direction starting from coil U1: coil U1, coil U2, coil W1, coil W2, coil V3, coil V4, coil U3, coil U4, coil W3, coil W4, coil V1, coil V2.

In the above embodiment, the multiple coils 42, i.e., coils U1 to U4, coils V1 to V4, and coils W1 to W4, are Δ-connected (delta-connected). In the case of Δ-connection, for example, a series circuit of two coils U1 and U2 is connected in parallel to a series circuit of two coils U3 and U4, a series circuit of two coils V1 and V2 is connected in parallel to a series circuit of two coils V3 and V4, and a series circuit of two coils W1 and W2 is connected in parallel to a series circuit of two coils W3 and W4. A so-called 2-series 2-parallel circuit is used for each of the U-phase, V-phase, and W-phase.

Note that the features of this disclosure are not limited to a delta connection. The multiple coils 42 may also be in a Y connection (star connection).

(3) Operation When current flows through each of the coils U1 to U4, V1 to V4, and W1 to W4, a magnetic field is generated. Each switch circuit that controls the current flow through each of the coils U1 to U4, V1 to V4, and W1 to W4 can change the direction and magnitude of the generated magnetic field by switching the direction of current flow and turning current on and off. In addition, each switch circuit supplies a drive current according to the rotational position of the rotor 4. This allows the rotor 4 to obtain a drive force according to the rotational position.

The coils U1 to U4, V1 to V4, and W1 to W4 are arranged on the same circumference with the axis C1 as the center. In this embodiment, the coil 42 is composed of 12 coils U1 to U4, V1 to V4, and W1 to W4.

For example, motor 1 is a 10-pole, 12-slot motor, and coils U1-U4, V1-V4, and W1-W4 switch current in accordance with the rotation of rotor 4 to maintain the rotation of rotor 4. In other words, the switching FET circuit changes the magnitude and direction of the current in coils U1-U4, V1-V4, and W1-W4, causing rotor 4 to rotate.

When the rotor 4 rotates, it may resonate, causing increased vibrations at certain speed ranges. Resonance occurs due to the natural frequency of the motor 1 and the vibrations that occur when the motor 1 is in operation. For this reason, in this embodiment, a metal frame 21 and a resin bracket 22 are used in the housing 2 to change the natural frequency of the motor 1 and the mechanism and the vibrations that occur when the motor 1 is in operation, thereby suppressing the vibrations.

(4) Advantages The motor 1 of this embodiment includes the rotor 4, the stator 3, and the housing 2.

The housing 2 houses or holds the rotor 4 and the stator 3. The housing 2 includes a bracket 22 that rotatably holds the first end of the rotating shaft 41, and a frame 21 that rotatably holds the second end of the rotating shaft 41. The frame 21 has an open opening 210. The bracket 22 has a base 221 and a flexure 63. The flexure 63 protrudes from an end 220 of the base 221 and is inserted into the frame 21 through the opening 210 in the frame 21. The flexure 63 has one of a protrusion 61 and a recess 62, and the frame 21 has the other of the recess and protrusion. The bracket 22 is fixed to the frame 21 in a manner that the bracket 22 is inserted into the opening 210 in the frame 21 by fitting the protrusion 61 into the recess 62.

This configuration makes it possible to provide a motor 1 that suppresses vibration.

In this embodiment, the frame 21 is made of metal and the bracket 22 is made of resin.

With this configuration, in the resonance that occurs due to the natural frequency of the motor 1 and the mechanism, and the vibration of the motor 1 during operation, the motor 1 employs a resin bracket 22, which changes the natural frequency and the vibration of the motor 1 during operation, thereby suppressing the vibration. In addition, resin has a high degree of freedom in terms of shape, which makes it easy to machine the recess 62 of the bracket 22.

(5) Modifications Modifications are listed below. The modifications described below can be applied in appropriate combination with the above embodiment.

(5-1) First Modification In the above embodiment, the recess 62 of the flexure 63 is configured as a rectangular half-punched portion 66, but the present invention is not limited to this configuration. FIG. 6 shows an external view of a motor 1A according to the first modification. The recess formed in the flexure 63 of the motor 1A may be a round recess 67 as shown in FIGS. 7 and 8. FIG. 9 shows a cross-sectional view of the motor 1A. FIG. 10A shows an enlarged view of a cross section (Z1 region) of the fitting portion 6A including the round recess 67. In the case of the round recess 67, the round fitting portion 6A (the protrusion 61A and the recess 67) can exert a fitting force even when a force is applied in the direction in which the frame 21A and the bracket 22A push against each other and in the direction in which the frame 21A and the bracket 22A pull against each other. For this reason, there is a possibility that the shape of the recess 62 in the first embodiment is more versatile than the rectangular half-punched portion 66.

(5-2) Second Modification In the above embodiment, as shown in Fig. 10A, the recess 67 of the bracket 22A and the protrusion 61A of the frame 21A are fitted together to form the fitting portion 6A, but the present invention is not limited to this configuration. As shown in Fig. 10B, the frame 21B may have a recess 67B, and the bracket 22B may have a protrusion 61B.

(5-3) Third Modification In the above embodiment, as shown in Figs. 3 and 5, the recess 62 of the flexible portion 63 is configured as a rectangular half-punched portion 66, but is not limited to this configuration. The recess of the flexible portion 63 may be an elliptical recess 68 as shown in Fig. 11. In the case of the elliptical recess 68, the elliptical fitting portion can exert a fitting force even when a force is applied in a direction in which the frame and the bracket 22C push against each other and in a direction in which the frame and the bracket 22C pull each other. In addition, by making the recess 68 elliptical, the area of the fitting portion can be increased, and the strength when a force is applied can be increased compared to the round recess 67 (see Fig. 8). Furthermore, by increasing the area of the fitting portion, the elliptical recess 68 may exert a greater fitting force than the recess 62 (half-punched portion 66) of the embodiment.

(5-4) Fourth Modification In the above embodiment, the motor 1 is configured as a combination of a metal frame 21 and a resin bracket 22, but is not limited to this configuration. As long as the configuration of the fitting portion 6 including the convex portion 61 and the concave portion 62 and the bending portion 63 that bends like a hinge are ensured, the combination of the frame 21 and the bracket 22 may be a metal frame 21 and a metal bracket 22, a resin frame 21 and a metal bracket 22, or a resin frame 21 and a resin bracket 22. When metal is used as the material, strength and heat dissipation can be expected, and when resin is used as the material, freedom in design of the shape, suppression of vibration, light weight, low cost, etc. can be expected.

(5-5) Fifth Modification In the above embodiment, the motor is configured as a three-phase motor with 10 poles, but is not limited to this configuration. The motor may have 8 poles, which is less than 10 poles, or 18 poles, which is more than 10 poles. The number of positioning portions 64 and the number of flexible portions 63 may also be changed depending on the number of poles. It is preferable that there are three or more flexible portions, but the number may be one, two, or four or more.

(5-6) Sixth Modification In the above embodiment, the length of the positioning portion 64 protruding from the end of the bracket 22 is longer than the length of the flexible portion 63 protruding from the end of the bracket 22, but the present invention is not limited to this configuration. For example, in the case where the press-fitted core has a notch, the length of the flexible portion 63 may be longer than the length of the positioning portion 64.

(5-7) Seventh Modification In the above embodiment, the rotor 4 is a surface permanent magnet rotor, i.e., an SPM (Surface permanent Magnet) type rotor, in which a plurality of permanent magnets 46 are arranged on the surface of the rotor core 40, but the rotor 4 is not limited to being an SPM type rotor. The rotor 4 may be an interior permanent magnet rotor, i.e., an IPM (Interior Permanent Magnet) type rotor, in which a plurality of permanent magnets 46 are embedded in the rotor core 40. When the rotor 4 is an IPM type rotor, for example, the plate-shaped permanent magnets 46 are fitted into a plurality of holes formed in the rotor core 40.

(summary)
As described above, the motor (1, 1A) according to the first aspect includes the rotor (4), the stator (3), and the housing (2).

The rotor (4) includes a rotating shaft (41). The rotating shaft (41) has an axial center (C1) as its center of rotation and extends in the direction in which the axial center (C1) extends. The stator (3) is located opposite the rotor (4). The stator (3) supplies a magnetic force that rotates the rotor (4). The housing (2) accommodates or holds the rotor (4) and the stator (3). The housing (2) includes a bracket (22) that rotatably holds a first end of the rotating shaft (41), and a frame (21) that rotatably holds a second end of the rotating shaft (41). The frame (21) has an open opening (210). The bracket (22) has a base (221) and a flexible portion (63). The flexure (63) protrudes from the end (220) of the base (221) and is inserted into the frame (21) through an opening (210) in the frame (21). The flexure (63) has one of a protrusion (61) and a recess (62), and the frame (21) has the other of a recess (62) and a protrusion (61). The bracket (22) is fixed to the frame (21) in such a manner that the bracket (22) is inserted into the opening (210) in the frame (21) by fitting the protrusion (61) into the recess (62).

According to this embodiment, one of the frame (21) and bracket (22) that form the housing (2) has a convex portion (61), and the other has a concave portion (62). The convex portion (61) and the concave portion (62) fit together to fix the frame (21) and the bracket (22). Therefore, compared to when the frame (21) and the bracket (22) are fixed over the entire circumference, the fixed portions are limited, and vibrations of the motor (1, 1A) are less likely to be transmitted. Therefore, vibrations can be suppressed.

In the motor (1, 1A) according to the second aspect, the flexible portion (63) is accommodated inside the frame (21) while being flexible when inserted into the frame (21) in the first aspect.

According to this embodiment, the flexible portion (63) bends when inserting the bracket (22) into the frame (21), making it easier to insert the bracket (22) into the frame (21). In addition, the flexible portion (63) bends to absorb vibrations of the motor (1, 1A), thereby suppressing vibrations.

In the motor (1, 1A) according to the third aspect, in the first or second aspect, the frame (21) has a protruding portion (61). The protruding portion (61) protrudes from the inner surface of the frame (21) toward the rotating shaft (41). The flexible portion (63) has a recessed portion (62) and is movable in a direction perpendicular to the rotating shaft (41) (radial direction).

According to this configuration, the frame (21) has a convex portion (61) that protrudes from the inner surface of the frame (21) toward the rotation axis (41), which makes it easier to process the frame (21). In addition, the flexible portion (63) has a concave portion (62) and is movable in a direction perpendicular to the rotation axis (41), which allows it to absorb vibrations and therefore suppress vibrations.

In the motor (1, 1A) according to the fourth aspect, in any of the first to third aspects, the frame (21) and the bracket (22) are each formed of metal or resin.

According to this configuration, metal has strength and excellent heat dissipation properties compared to resin, and resin has a high degree of freedom in shape, light weight, and low cost compared to metal. Therefore, by forming each of the frame (21) and bracket (22) from metal or resin, the material options are expanded and the properties of each material can be utilized.

In the motor (1, 1A) according to the fifth aspect, in any one of the first to third aspects, the frame (21) is made of metal and the bracket (22) is made of resin.

With this configuration, the frame (21) is made of metal and the bracket (22) is made of resin, which allows the natural vibration frequency of the motor (1, 1A) to be changed and vibration to be suppressed. In addition, by making the bracket (22) of resin, it becomes easier to process the recess (62) by taking advantage of the freedom of shape of the resin.

In the motor (1, 1A) according to the sixth aspect, in any of the first to fifth aspects, one or more flexible portions (63) are formed on the bracket (22).

According to this embodiment, one or more flexible portions (63) are formed, thereby fixing the frame (21) and the bracket (22) together and suppressing vibration.

In the motor (1, 1A) according to the seventh aspect, in any of the first to sixth aspects, the bracket (22) further has a positioning portion (64) protruding from the end (220) of the base (221).

According to this embodiment, the positioning portion (64) can determine the positional relationship between the frame (21) and the bracket (22) as viewed from the axis (C1), so that the positional relationship between the frame (21) and the bracket (22) in the direction of the axis (C1) is stable.

In the motor (1, 1A) according to the eighth aspect, the length of the positioning portion (64) protruding from the end (220) of the base (221) is longer than the length of the flexible portion (63) protruding from the end (220) of the base (221) in the seventh aspect.

In this embodiment, the positioning portion (64) is longer than the bending portion (63), so that the fitting portion (6, 6A) can be formed with the bracket (22) and the frame (21) in a stable position.

In the motor (1, 1A) according to the ninth aspect, in the seventh or eighth aspect, the stator (3) has a stator core (30), a plurality of teeth (43), a coil (42), and an insulator (5). The plurality of teeth (43) protrude from the inner peripheral surface of the stator core (30) toward the rotating shaft (41). The coil (42) is formed by winding a conductor around each of the plurality of teeth (43), and generates a magnetic field when a current flows through the coil (42), thereby rotating the rotor (4). The insulator (5) is fitted to each of the plurality of teeth (43). The coil (42) is formed on the outer periphery of the insulator (5), thereby electrically insulating each of the plurality of teeth (43) from the coil (42). The motor (1, 1A) further includes a jumper (44) to one end of which a plurality of coils (42) are connected and to the other end of which a power source for energizing the coils is input. The insulator (5) has a protrusion (51) that accommodates the jumper (44). The position of the positioning portion (64) in the circumferential direction (A1) on the bracket (22) does not overlap with the protrusion (51) of the insulator (5) when viewed from the direction in which the axis (C1) of the frame (21) extends.

According to this embodiment, the position of the positioning portion (64) in the circumferential direction (A1) on the bracket (22) is such that it does not overlap with the protrusion portion (51) of the insulator (5) when viewed from the direction in which the axis (C1) extends, so that the positioning portion (64) can stably position the frame (21) and the bracket (22).

In the motor (1, 1A) according to the tenth aspect, in any one of the sixth to ninth aspects, the stator (3) has a stator core (30), a plurality of teeth (43), a coil (42), and an insulator (5). The plurality of teeth (43) protrude from the inner peripheral surface of the stator core (30) toward the rotating shaft (41). The coil (42) is formed by winding a conductor around each of the plurality of teeth (43), and generates a magnetic field when a current flows through the coil (42), thereby rotating the rotor (4). The insulator (5) is fitted to each of the plurality of teeth (43), and the coil (42) is formed on its outer periphery, thereby electrically insulating each of the plurality of teeth (43) from the coil (42). The motor (1, 1A) further includes a crossover wire (44) to one end of which the plurality of coils (42) are connected and to the other end of which a power source for energizing the coil is input. The insulator (5) has a protrusion (51) that accommodates the crossover wire (44). The position of the flexible portion (63) in the circumferential direction (A1) on the bracket (22) overlaps with the protrusion (51) of the insulator (5) when viewed from the direction in which the axis (C1) extends.

According to this embodiment, the circumferential (A1) position of the flexible portion (63) on the bracket (22) overlaps with the protrusion (51) of the insulator (5) when viewed from the direction of the axis (C1) of the frame (21), thereby making effective use of the space in the circumferential (A1) direction.

In the motor (1) according to the eleventh aspect, in any of the first to tenth aspects, the shape of the recess (62) is rectangular when viewed from the front in the radial direction (A2) of the bracket (22).

In this embodiment, the shape of the recess (62) is rectangular, so that the mating portion (6) is rectangular, and the mating strength can be exerted when the frame (21) and the bracket (22) are pulled in opposite directions.

In the motor (1A) according to the twelfth aspect, in any of the first to tenth aspects, the shape of the recess (62) is circular when viewed from the front in the radial direction (A2) of the bracket (22A).

According to this embodiment, the shape of the recess (62) is a round recess (67), so that the fitting portion (6A) is round, and when a force is applied in a direction in which the frame (21A) and the bracket (22A) are pushed against each other and in a direction in which they are pulled in the opposite direction, the strength of the fitting can be exhibited.

In the motor (1) according to the thirteenth aspect, in any of the first to tenth aspects, the shape of the recess (62) is elliptical when viewed from the front in the radial direction (A2) of the bracket (22C).

According to this embodiment, the shape of the recess (62) is an elliptical recess (68), so that the fitting portion is elliptical, and when a force is applied in a direction in which the frame and the bracket (22C) are pushed against each other and in a direction in which they are pulled in the opposite direction, the strength of the fitting can be exhibited. Since the area of the elliptical recess (68) is larger than that of the round recess (67), the strength of the fitting is stronger than that of the round recess (68).

REFERENCE SIGNS LIST 1, 1A motor 2 housing 3 stator 4 rotor 5 insulator 6, 6A mating portion 21, 21A, 21B frame 22, 22A, 22B, 22C bracket 41 rotating shaft 42 coil 43 teeth 44 crossover wire 51 protrusion 61, 61A, 61B convex portion 62 concave portion 63 flexure portion 64 positioning portion 66 half-punched portion 67 round concave portion 68 oval concave portion 210 opening 220 end portion 221 base A1 circumferential direction C1 axis

Claims (13)

A rotor including a rotation shaft having an axis as a rotation center and extending in a direction in which the axis extends;
a stator positioned opposite the rotor and supplying a magnetic force for rotating the rotor;
a housing that houses or holds the rotor and the stator,
The housing includes:
a bracket that rotatably holds a first end of the rotating shaft;
a frame that rotatably holds the second end of the rotating shaft,
The frame has an opening,
The bracket is
With the base,
a flexible portion protruding from an end of the base and inserted into the frame through the opening in the frame,
The flexible portion has one of a convex portion and a concave portion,
the frame has the other of the recess and the protrusion,
The bracket is fixed to the frame in a manner that the bracket is inserted into the opening of the frame by fitting the protrusion into the recess.
Motor. The flexible portion is accommodated in the interior of the frame while being flexible when inserted into the interior of the frame.
The motor according to claim 1 . The frame has the protrusion,
the protrusion protrudes from an inner surface of the frame toward the rotation shaft,
The flexible portion has the recess and is movable in a direction perpendicular to the rotation axis.
3. The motor according to claim 1 or 2. Each of the frame and the bracket is formed of metal or resin.
The motor according to any one of claims 1 to 3. The frame is made of metal, and the bracket is made of resin.
The motor according to any one of claims 1 to 3. The flexible portion is formed in one or more of the brackets.
The motor according to any one of claims 1 to 5. The bracket further includes a positioning portion protruding from the end of the base.
The motor according to any one of claims 1 to 6. a length of the positioning portion protruding from the end of the base is longer than a length of the flexible portion protruding from the end of the base;
8. The motor according to claim 7. The stator includes:
A stator core;
a plurality of teeth protruding from an inner surface of the stator core toward the rotating shaft;
a coil formed by winding a conductor around each of the plurality of teeth, the coil generating a magnetic field when a current flows therethrough, thereby rotating the rotor;
an insulator fitted to each of the plurality of teeth;
The insulator electrically insulates each of the teeth from the coil by forming the coil on an outer periphery of the insulator,
The motor further includes a crossover wire having one end connected to the plurality of coils and having the other end connected to a power source for energizing the coils,
The insulator has a protrusion that receives the crossover wire,
a circumferential position of the positioning portion on the bracket does not overlap with the protrusion of the insulator when viewed from a direction in which the axis extends;
9. A motor according to claim 7 or 8. The stator includes:
A stator core;
a plurality of teeth protruding from an inner surface of the stator toward the rotating shaft;
a coil formed by winding a conductor around each of the plurality of teeth, the coil generating a magnetic field when a current flows therethrough, thereby rotating the rotor;
an insulator fitted to each of the plurality of teeth and having the coil formed on an outer periphery thereof, thereby electrically insulating each of the plurality of teeth from the coil;
The motor further includes a crossover wire having one end connected to the plurality of coils and having the other end connected to a power source for energizing the coils,
The insulator has a protrusion that receives the crossover wire,
a circumferential position of the flexible portion on the bracket overlaps with the protrusion of the insulator when viewed from a direction in which the axis extends;
The motor according to any one of claims 6 to 9. The shape of the recess is rectangular when viewed from the front in the radial direction of the bracket.
The motor according to any one of claims 1 to 10. The shape of the recess is circular when viewed from the front in the radial direction of the bracket.
The motor according to any one of claims 1 to 10. The shape of the recess is an ellipse when viewed from the front in the radial direction of the bracket.
The motor according to any one of claims 1 to 10.

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