Electric Motor

Abstract

Provided is a motor having a bushing capable of preventing a hinge (part) from being damaged. The motor (1) comprises: a stator (2) having a stator core (21) and a winding (23), a motor housing (6) covering the same stator, a circuit substrate arranged in the motor housing, and a bushing (7) mounted on the motor housing and holding wiring led from the circuit substrate to the outside of the motor housing. The bushing comprises a first retaining piece (7A), a second retaining piece (7B), and a hinge part (73) that connects one end (7C) of the first retaining piece and the second retaining piece to each other and opens and closes in a direction that brings the other end (7AC, 7BC) of the first retaining piece and the second retaining piece closer to or farther from each other. An angle limiting part (74) that limits the opening angle of the hinge part is provided on each of the first retaining piece and the second retaining piece.

Description

Technical Field

[0001] The present invention relates to a motor provided with a bushing through which wiring of a control circuit board passes. Background Art

[0002] Among conventional electric motors, an inner rotor type permanent magnet motor is known, in which a rotor having a permanent magnet is rotatably arranged inside a stator that generates a rotating magnetic field. For example, this permanent magnet motor is used for rotationally driving a blower fan mounted in an air conditioner.

[0003] As is well known, such a permanent magnet motor has a control circuit board inside, and wiring connected to the circuit board is led out to the outside through a bushing.

[0004] As such a bushing, there is a bushing which is divided into a pair of holding pieces, namely, a first holding piece and a second holding piece, and the two are connected by a connecting portion (for example, refer to Patent Document 1).

[0005] The bushing is divided into two holding pieces, so that the wiring operation through the bushing becomes easy. In addition, the two holding pieces are connected via the connecting portion, so that the two holding pieces are not separated and the assembly performance is improved.

[0006] Prior Art Literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2013-138551 Summary of the invention

[0009] (Problem to be solved by the invention)

[0010] Considering the assembly performance, a hinge is usually used as the connecting part. In this case, if the hinge is opened too much, the load acts on the hinge, causing the hinge to be damaged, and there is a possibility that the bushing will be damaged. It is desired to prevent such damage.

[0011] Therefore, an object of the present invention is to provide a motor including a bushing capable of preventing damage to a hinge (portion).

[0012] (Technical solutions to solve problems)

[0013] One embodiment of the electric motor of the present invention comprises: a stator having a stator core and a winding; a motor housing covering the stator; a circuit substrate arranged in the motor housing; and a bushing installed in the motor housing and holding wiring led out from the circuit substrate to the outside of the motor housing.

[0014] The bushing has a first retaining piece, a second retaining piece and a hinge. The hinge connects one end of the first retaining piece to one end of the second retaining piece, and opens and closes in a direction that makes the other end of the first retaining piece and the other end of the second retaining piece approach or move away from each other. An angle limiting part is provided on the first retaining piece and the second retaining piece, respectively, and the angle limiting part limits the opening angle of the hinge.

[0015] According to the present invention, it is possible to prevent the hinge in the bushing of the motor from being damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a perspective view of a rotor of a permanent magnet motor according to the present invention.

[0017] Figure 2 It is a perspective view of a rotor, a shaft, and a second bearing of a permanent magnet motor according to the present invention.

[0018] Figure 3 Yes means Figure 2 A three-dimensional diagram of the rotor after being assembled to the motor housing.

[0019] Figure 4 It is a cross-sectional view of the permanent magnet motor according to the present invention.

[0020] Figure 5 The present invention is an enlarged perspective view (a) and an enlarged top view (b) showing a housing groove of a motor housing for housing a bushing according to the present invention.

[0021] Figure 6 This is a front perspective view of a bushing in a closed state according to an embodiment of the present invention.

[0022] Figure 7 yes Figure 6 A back side stereogram (a) and a front side stereogram (b) of the bushing in an open state.

[0023] Figure 8 1 and 2 . A rear view (a) of a bushing according to one embodiment of the present invention in an open state and a rear view (b) of a bushing according to another first embodiment of the present invention in an open state.

[0024] Fig. 9 It is a rear view (a) of a bushing in an open state and a rear view (b) of a bushing in a closed state according to another second embodiment of the present invention.

[0025] Fig.10 Yes means Figure 6 The bushing is installed to Figure 3 (a) is a perspective view of the motor in front of the housing, and (b) is a perspective view of the motor after installation.

[0026] Fig.11 Yes means Figure 6 The bushing is accommodated into Figure 5 An enlarged stereoscopic view (a) and an enlarged top view (b) of the state after the receiving groove is formed.

[0027] Fig.12 It is a perspective view of the permanent magnet motor according to the present invention.

[0028] Fig.13 It is a longitudinal sectional view of the permanent magnet motor according to the present invention. DETAILED DESCRIPTION

[0029] An embodiment of the present invention will be described below with reference to the accompanying drawings. In the following description of the drawings, the same or similar parts are marked with the same or similar symbols. However, it should be noted that the drawings are schematic diagrams and may be different from the actual situation. Therefore, the specific components should be judged with reference to the following description.

[0030] In addition, the embodiments shown below are examples of implementation methods of the device and method for embodying the technical concept of the present invention, and the technical concept of the present invention does not specify the shape, structure, configuration, etc. of the constituent components as the following. The technical concept of the present invention can be modified in various ways within the technical scope specified by the claim items recorded in the scope of the protection requested.

[0031] Next, a motor according to an embodiment of the present invention will be described.

[0032] (Overall structure of the motor)

[0033] Figures 1 to 13 1 and 2 are diagrams for explaining the structure of the motor 1 in the present embodiment. As shown in these diagrams, the permanent magnet motor 1 is, for example, a brushless DC motor. Although the motor 1 is not shown, the motor is used, for example, to drive a blower fan mounted in an outdoor unit of an air conditioner to rotate.

[0034] The following is an example of an inner rotor type permanent magnet motor 1, in which a rotor 3 having a permanent magnet 31 is rotatably arranged inside a stator 2 that generates a rotating magnetic field. The permanent magnet motor 1 in this embodiment has a stator 2, a rotor 3 and a motor housing (casing) 6.

[0035] (stator, rotor and motor housing)

[0036] like Figure 3 , Figure 4 and Fig.13As shown in FIG. 1 , the stator 2 includes: a stator core 21 having a cylindrical yoke and a plurality of teeth extending from the yoke toward the inner diameter side; and a winding 23 wound around the teeth through an insulating member 22. The stator 2 is covered by a motor housing 6 formed of resin except for the inner circumferential surface of the stator core 21. That is, the motor housing 6 covers the stator 2 (stator) having the stator core 21 and the winding 23. The motor housing 6 can be formed of metal such as steel plate and aluminum.

[0037] like Figure 5 and Fig.10 As shown, at the end of the motor 1 on the opposite side of the output, a groove 64 is formed in the motor housing 6, and the bushing 7 described later is installed in the groove. The shape of the groove 64 (and the second flange 712 of the bushing 7) can be any shape as long as the bushing 7 can be installed (held) on the motor housing 6. In this embodiment, the groove 64 is a notch that has a bottom on the output side of the central axis O of the motor housing 6 (hereinafter referred to as the central axis direction) and penetrates in the radial direction, and is approximately rectangular.

[0038] The groove portion 64 is provided with a wall portion 641 against which a second flange portion 712 of the bushing 7 described later abuts, thereby restricting radial movement of the bushing 7. Figure 5 As shown in (b), the groove portion 64 is convex toward the outer diameter side when viewed from the central axis direction.

[0039] At the bottom of the groove 64 of the motor housing 6, a waterproof wall 643 is provided to cover the notch 714 in the radial direction in order to prevent water and dust from entering the notch 714 of the second flange 712 described later. In addition, similar to the wall 641, the waterproof wall 643 abuts against the second flange 712 of the bushing 7 described later and restricts the movement of the bushing 7 in the radial direction.

[0040] Furthermore, a bottomed hole 642 (recessed portion) is provided in the groove 64, and an angle restricting portion 74 of the second flange 712 described later is located in the hole. The hole 642 is rectangular in shape when viewed from the central axis direction.

[0041] The rotor 3 is rotatably arranged with a predetermined gap (clearance) on the inner circumference of the stator core 21 of the stator 2. Figure 2 , Fig.13 As shown in FIG. 1 , the rotor 3 is a surface magnet type in which a permanent magnet 31 is annularly arranged on the outer peripheral surface facing the stator core 21. The permanent magnet 31 is fixed around the shaft 35 via the outer peripheral side core 32, the insulating member 33, and the inner peripheral side core 34. The shaft 35 is supported by a first bearing 41 and a second bearing 42, and the first bearing 41 is supported by a first bracket 51, and the second bearing 42 is supported by a second bracket 52, respectively, so that the rotor 3 is rotatably supported.

[0042] (Bearings and brackets)

[0043] like Fig.13 As shown, the first bearing 41 rotatably supports one end (output side) of the shaft 35 of the rotor 3. The second bearing 42 rotatably supports the other end (opposite to output side) of the shaft 35 of the rotor 3. For example, ball bearings are used for the first bearing 41 and the second bearing 42.

[0044] The first bracket 51 is made of metal (steel plate, aluminum, etc.) and is located at one end of the motor housing 6 in the central axis direction, that is, at the output side of the shaft 35. The first bracket 51 is insert-molded when the motor housing 6 is molded and is integrated with the motor housing 6.

[0045] The second bracket 52 is made of metal (steel plate, aluminum, etc.). Fig.12 and Fig.13 As shown, it is fixed to the other end side in the central axis direction of the motor housing 6, that is, the output opposite side of the shaft 35. The second bracket 52 is generally formed in a circular plate shape and has an outer edge portion 520 that abuts against the end surface in the central axis direction of the motor housing 6, and the outer edge portion 520 is threadedly connected to the outer edge portion of the motor housing 6. In addition, in the central part of the second bracket 52, a second bearing accommodating portion 522 for accommodating the second bearing 42 is formed on the inner surface side (output side) thereof.

[0046] In addition, the second bracket 52 has a heat dissipation fin 523 erected outward (opposite to the output side) on the opposite side of the second bracket, and is in contact with the circuit board 82 for controlling the motor 1 through the heat conduction member 81. That is, the second bracket 52 also functions as a heat sink that dissipates heat from the circuit board 82 (particularly the electronic component 821 mounted on the circuit board 82) to the outside of the motor 1.

[0047] (Insulation structure of rotor 3)

[0048] In order to prevent electrical corrosion from occurring in the first bearing and the second bearing 42, Figure 1 As shown in FIG. 1 , in the permanent magnet motor 1 configured as described above, an insulating member 33 is provided in a part of the rotor 3. Next, the insulating structure of the rotor 3 will be briefly described.

[0049] like Figures 1 to 4 As shown, the rotor 3 includes a permanent magnet 31 , an outer circumference side iron core 32 , an insulating member (connecting portion) 33 , an inner circumference side iron core 34 , and a shaft 35 from the outer diameter side to the inner diameter side.

[0050] like Figure 2 and Figure 4As shown, the permanent magnet 31 is formed into a ring shape with a plurality of (e.g., 8 or 10) permanent magnet pieces 311 so that the N poles and the S poles alternately appear at equal intervals in the circumferential direction. Furthermore, the permanent magnet 31 can use a plastic magnet formed into a ring shape by solidifying magnetic powder with resin.

[0051] like Figures 1 to 4 As shown in the figure, the outer circumferential side iron core 32 is formed in an annular shape and is located on the inner diameter side of the permanent magnet 31. The outer circumferential side iron core 32 has a plurality of (for example, 10 in the circumferential direction) outer circumferential side protrusions 322 protruding from the outer circumferential surface to the outer diameter side in order to position the permanent magnet 31. For example, the outer circumferential side protrusions 322 are formed to extend from one end to the other end of the outer circumferential side iron core 32 in the direction of the central axis.

[0052] like Figures 1 to 4 As shown, the inner circumference side iron core 34 is formed in an annular shape and is located on the inner diameter side of the outer circumference side iron core 32. In addition, at the center of the inner circumference side iron core 34, there is a through hole 343 that penetrates in the direction of the central axis. The shaft 35 is fixed in the through hole 343 provided in the inner circumference side iron core 34 by pressing, riveting, etc. In addition, the inner circumference side iron core 34 may have a plurality of through holes 342 for thinning to reduce weight between the through hole 343 and the outer circumference of the inner circumference side iron core 34. Viewed from the direction of the central axis, the plurality of through holes 342 are arranged at equal intervals in the circumferential direction so that the shape of the inner circumference side iron core 34 formed with the through holes 342 is spoke-shaped.

[0053] The insulating member 33 is formed of a dielectric resin such as PBT (polybutylene terephthalate) or PET (polyethylene terephthalate), and is located between the outer iron core 32 and the inner iron core 34. The insulating member 33 is formed integrally with the outer iron core 32 and the inner iron core 34 by insert molding in which a resin is filled between the outer iron core 32 and the inner iron core 34. The insulating member 33 reduces the electrostatic capacitance between the outer iron core 32 and the inner iron core 34 (a part of the electrostatic capacitance between the winding 23 of the stator 2 and the shaft 35), and is adjusted so that the potential difference between the inner ring side and the outer ring side is reduced by lowering the potential on the inner ring side of the first bearing 41 and the second bearing 42, thereby preventing electrical corrosion of the bearings.

[0054] (Structure, function and effect of bushing involved in the present invention)

[0055] The motor 1 includes a bushing 7 for passing wiring through the inside of the motor housing 6. Fig.13 As shown in FIG. 1 , the motor 1 includes a motor housing 6 and a circuit board 82 disposed in the motor housing 6. The circuit board 82 is disposed at a position between the rotor 3 and the second bearing 42 in the central axis direction. Fig.10As shown, the bushing 7 is mounted on the motor housing 6 , and holds wiring (not shown) led out from the circuit board 82 (not shown) to the outside of the motor housing 6 .

[0056] Figures 6 to 8 It is a figure explaining the structure of the bushing 7 in this embodiment.

[0057] The bushing 7 includes a mounting portion 71 mounted on the groove portion 64 of the motor housing 6 and a wiring passage portion 72 through which wiring is passed. The wiring passage portion 72 is cylindrical and allows wiring to pass through the inside. The mounting portion 71 is rectangular and is integrated with the wiring passage portion 72, and allows wiring to pass through the inside. Figure 6 The mounting portion 71 and the wiring passage portion 72 are not limited to the above-mentioned shapes.

[0058] The wiring passage 72 has a plurality of protrusions 721 on the cylindrical outer peripheral surface. This improves the strength of the wiring passage 72. In the present embodiment, as an example, four of the plurality of protrusions 721 are provided at equal intervals in the circumferential direction.

[0059] The mounting portion 71 may be formed with a plurality of bottomed thinning grooves 713 along the cylindrical axis of the wiring through portion 72. In the present embodiment, the thinning groove 713 is provided with four holes having a substantially triangular prism shape with arc-shaped curved sides at positions that do not overlap with the convex portions 721 provided on the outer peripheral surface of the cylindrical wiring through portion 72 in the X-axis direction.

[0060] like Fig.11 As shown, on the outer surface side of the mounting portion 71 ( Figure 6 The upper part of the X-axis positive side) ( Figure 6 The first flange portion 711 is provided on the positive side of the Z axis in the Y axis direction. The first flange portion 711 cooperates with the upper end portion of the outer peripheral surface of the motor housing 6 to limit the radial movement of the bushing 7 and fix the bushing 7 to the motor housing 6 (refer to Figures 6 to 11 ).

[0061] like Fig.11 As shown, on the inner surface side of the mounting portion 71 ( Figure 6 The lower part (negative side of the X axis) Figure 6 A second flange portion 712 extending in the Y-axis and Z-axis (central axis O) is provided on the negative side of the Z axis in the motor housing 6. The second flange portion 712 cooperates with the wall portion 641 and the waterproof wall portion 643 provided in the groove portion 64 of the motor housing 6 to restrict the movement of the bushing 7 in the radial direction and fix the bushing 7 to the motor housing 6 (refer to Figures 6 to 11 ).

[0062] In the present embodiment, the end of the first flange portion 711 on the negative side in the Z axis and the end of the second flange portion 712 on the positive side in the Z axis are at the same height (same position in the Z axis) when viewed from the X axis direction.

[0063] Note that the first flange portion 711 and the second flange portion 712 are not limited to the above-described shapes as long as they can restrict the movement of the bushing 7 relative to the motor housing 6 .

[0064] like Figure 7 As shown, the bushing 7 is in the Y-axis direction (refer to Figure 6 ) is divided into a first retaining piece 7A and a second retaining piece 7B from the upper part (Z-axis positive side) of the bushing 7, and the first retaining piece 7A and the second retaining piece 7B are integrally connected by a hinge portion 73 provided at the lower part (Z-axis negative side) of the bushing 7. Therefore, the first flange portion 711 and the second flange portion 712 are respectively formed on the first retaining piece 7A and the second retaining piece 7B (refer to Figure 7 ).

[0065] The bushing 7 includes a first holding piece 7A, a second holding piece 7B, and a hinge portion 73. The hinge portion 73 connects the first holding piece 7A in the Z-axis direction (see Figure 6 ) is connected to one end 7C of the second retaining piece 7B in the Z-axis direction, and is opened and closed in a direction that brings the other end 7AC of the first retaining piece 7A in the Z-axis direction closer to or farther away from the other end 7BC of the second retaining piece 7B in the Z-axis direction.

[0066] The hinge portion 73 is a thin-walled (for example, 0.5 mm thick) and bendable movable hinge integrally formed between the first retaining piece 7A and the second retaining piece 7B. Furthermore, in the present embodiment, in the hinge portion 73, the width of the portion connecting the first retaining piece 7A and the second retaining piece 7B is shortened. In other words, one end 7C of the first retaining piece 7A and one end 7C of the second retaining piece 7B are connected by the hinge portion 73 in a close state. Thus, it is possible to prevent the hinge portion 73 from protruding too much from the outer surface of the bushing 7 when the other end 7AC of the first retaining piece 7A and the other end 7BC of the second retaining piece 7B are brought close to each other. Therefore, when the bushing 7 is as shown in FIG. Fig.10 When the motor housing 6 is mounted in the groove 64 as shown, there is no need to provide a large clearance portion in the groove 64 to avoid the hinge portion 73. In addition, the gap between the motor housing 6 and the bushing 7 can be reduced thereby, and water and dust can be prevented from seeping out of the gap.

[0067] On the other hand, in the hinge portion 73, when the width of the portion connecting the first holding piece 7A and the second holding piece 7B is short, the hinge portion 73 is difficult to deform. Therefore, the force required to open the bushing 7 increases, and as a result, the stress generated in the hinge portion 73 when the bushing 7 is opened increases. In other words, the following problem occurs: an excessive load is applied to the hinge portion 73 due to the action of opening the bushing 7, and the hinge portion 73 is easily damaged. In order to solve this problem, in the present embodiment, an angle limiting portion 74 is provided to limit the opening angle of the bushing 7.

[0068] A first engaging portion 715A is formed at a portion close to one end 7C of the first retaining piece 7A, and a first engaging portion 715B is formed at a portion close to one end 7C of the second retaining piece 7B. The first engaging portion 715A of the first retaining piece 7A and the first engaging portion 715B of the second retaining piece 7B engage with each other when the bushing 7 is closed by the hinge portion 73. In addition, a second engaging portion 716A is formed at the other end 7AC of the first retaining piece 7A, and a second engaging portion 716B is formed at the other end 7BC of the second retaining piece 7B. The second engaging portion 716A of the first retaining piece 7A and the second engaging portion 716B of the second retaining piece 7B engage with each other when the hinge portion 73 is closed. In addition, these engaging portions 715A, 715B, 716A, 716B also function as a labyrinth structure that prevents water and dust from passing from these engaging portions to the X-axis direction of the bushing 7 when the bushing 7 is closed by the hinge portion 73. The second engaging portions 716A and 716B form a two-stage maze structure of a semi-cylindrical shape and a rectangular shape in the X-axis direction to enhance the sealing effect.

[0069] The second flange portion 712A of the first holding piece 7A and the second flange portion 712B of the second holding piece 7B, the one end portion 7C of the first holding piece 7A and the one end portion 7C of the second holding piece 7B are respectively formed with notches 714A and 714B (see Figure 7 and 8 ). Thus, the bushing 7 can perform an opening and closing action centered on the hinge portion 73. In addition, by forming the notch portions 714A and 714B, notch surfaces (first limiting surface 714C and second limiting surface 714D) facing each other are formed on each of the first holding piece 7A and the second holding piece 7B.

[0070] Furthermore, each of the first holding piece 7A and the second holding piece 7B is provided with an angle limiting portion (stopper) 74 that limits the opening angle of the bush 7. In other words, the angle limiting portion 74 is formed at the second flange portion 712A of the first holding piece 7A and the second flange portion 712B of the second holding piece 7B, respectively.

[0071] In this embodiment, if Figure 7 and 8As shown in FIG. 1 , the first retaining piece 7A and the second retaining piece 7B are respectively provided with the above-mentioned notch surfaces (restriction surfaces 714C, 714D) as the angle restricting portion 74. For example, Figure 7 (b) Figure 8 As shown in FIG. 2( a ), the angle limiting portion 74 (limiting surfaces 714C, 714D) is formed at a portion of the second flange portions 712A, 712B close to the hinge portion 73 .

[0072] Moreover, for example, Figure 8 As shown in (a), when the bushing 7 is opened, the ends of the restriction surfaces 714C and 714D abut against each other, so that the bushing 7 does not open further. Thus, the opening angle of the bushing 7 can be restricted.

[0073] In addition, the angle limiting portion 74 is not only applicable to the case where the opening angle is limited by directly contacting a portion of each limiting surface 714C, 714D set on the first retaining piece 7A and the second retaining piece 7B, but can also be applied to the case where the opening angle of the bushing 7 is indirectly limited via components located between opposing notch surfaces (limiting surfaces 714C, 714D).

[0074] For example, Figure 8 As shown in (b), when the thickness t of the flange connecting portion 714E connecting the second flange portions 712A and 712B to each other is large, when the bushing 7 is to be closed, the thick-walled flange connecting portion 714E is located between the opposing notch surfaces (limiting surfaces 714C, 714D), thereby indirectly preventing the opposing notch surfaces (limiting surfaces 714C, 714D) from approaching each other, thereby limiting the opening angle of the bushing 7.

[0075] Angle limiting portion 74 ( Figure 8 The limiting surfaces 714C and 714D in (a) are Figure 8 The limiting surfaces 714C, 714D and the flange connection portion 714E in (b) are provided at the one end portion 7C of the first holding piece 7A and the one end portion 7C of the second holding piece 7B, adjacent to the hinge portion 73. That is, the angle limiter 74 is provided on the side opposite to the opening side of the bushing 7 (the one end portion 7C side). Thus, the opening angle of the bushing 7 can be limited by a simple mechanism (angle limiter 74). In addition, the enlargement of the angle limiter 74 can be prevented.

[0076] By providing the second flange portion 712A and the angle restriction portion 74 , it is possible to simultaneously restrict the movement of the bush 7 in the radial direction of the electric motor 1 and restrict the opening angle of the bush 7 .

[0077] In this embodiment, although the angle limiting portion 74 is formed in the X-axis direction of the bushing 7 (see Figure 6), but is not limited to this, and may extend partially (for example, from one end to the center of the bushing 7 in the X-axis direction) or entirely (from one end to the other end of the bushing 7 in the X-axis direction) as long as it can function as a stopper. In addition, in the present embodiment, although the angle limiting portion 74 is integrally formed with the bushing 7, the angle limiting portion may be bonded to the notch surface (limiting surfaces 714C, 714D) of the bushing 7 as a separate member such as a resin or an elastic member.

[0078] As described above, when the bushing 7 is opened, the first holding piece 7A and the second holding piece 7B rotate around the hinge portion 73. At this time, the angle limiting portion 74 functions as a stopper to limit the rotation angle. This can prevent the bushing 7 from being opened excessively and prevent the hinge portion 73 from being damaged.

[0079] Fig. 9 1 is a rear view of a bushing 7' according to another embodiment. The bushing 7' is a cuboid or rectangular member (mounting portion) 71', and a through hole 72' is formed in the center of the member 71' for passing wiring. A second flange portion 712' extends from one side of the back side of the bushing 7' on the Y axis and the Z (O) axis.

[0080] and Figure 7 Similarly, the bushing 7 in the embodiment is a pair of first and second retaining pieces 7A and 7B, and includes a pair of components (mounting portions) 71A', 71B' and a pair of flange portions 711A', 711B'. These components rotate around the hinge portion 73', thereby opening and closing the bushing 7'.

[0081] Moreover, if Fig. 9 As shown, in a pair of flange portions 711A', 711B', notch portions 714A', 714B' are formed at the other end portions 7AC, 7BC of the first retaining piece and the second retaining piece. Thus, the bushing 7' can be opened and closed with the hinge portion 73' as the center. In addition, a pair of notch surfaces (first limiting surface 714C, second limiting surface 714D) facing each other are formed on surfaces that are close to each other when the bushing 7' is opened.

[0082] In this embodiment, a pair of notch surfaces (the first restriction surface 714C and the second restriction surface 714D) restrict the opening angle of the hinge portion 73. That is, the first restriction surface 714C and the second restriction surface 714D function as the angle restriction portion 74.

[0083] When the bushing 7 is Fig. 9When the sleeve 7' is opened as shown, the first retaining piece 7A' and the second retaining piece 7B' rotate around the hinge 73'. At this time, the first limiting surface 714C and the second limiting surface 714D are in surface contact and function as an angle limiting portion (stopper) to prevent the sleeve 7' from opening more than necessary. This can prevent the sleeve 7' from being opened excessively and prevent damage to the hinge 73'.

[0084] In this case, when the bushing 7' is closed (see Fig. 9 (a)) The angle between the first limiting surface 714C and the second limiting surface 714D becomes the angle between the first limiting surface 714C and the second limiting surface 714D when the bushing 7' is fully opened (refer to Fig. 9 (b)) The opening angle (the angle formed by the respective dividing surfaces 7D of the first holding piece 7A' and the second holding piece 7B') is restricted.

[0085] Furthermore, in Fig. 9 In (b), when the bushing 7' is fully opened, the angle formed by the dividing surfaces 7D of the first retaining piece 7A' and the second retaining piece 7B' is (at Fig. 9 The angle between the first limiting surface 714C and the second limiting surface 714D when the bushing 7' is closed as shown in (a) is 105.6 degrees, but the angle is not limited thereto as long as it is within a predetermined range (for example, greater than 45 degrees and less than 135 degrees) that can prevent damage to the hinge portion 73'.

[0086] The bushings 7, 7' described above are integrally formed components of the first retaining pieces 7A, 7A' and the second retaining pieces 7B, 7B', and are formed, for example, by resin injection molding. When the bushings 7, 7' are formed by resin injection molding, the opening angle of the bushings 7, 7' in a normal state without external force being applied can be easily determined by adjusting the opening angle at the manufacturing time of the bushings 7, 7'.

[0087] For example, when the bushings 7 and 7' are injection molded, the bushings 7 and 7' may be molded into a slightly opened state (for example, Fig. 9 In (b), the angle formed by the respective dividing surfaces 7D of the first holding piece 7A' and the second holding piece 7B' is greater than or equal to 35 degrees and less than or equal to 125 degrees).

[0088] Thus, even in a normal state where no external force is applied, the bushings 7 and 7 ′ are slightly opened, and the operation of opening the bushings 7 and 7 ′ can be omitted when passing the wiring through the wiring passage 72 , thereby improving workability.

[0089] After the wiring passes through the wiring through portion 72, the second flange portion 712 of the bushing 7 (7') is inserted into the groove portion 64 of the motor housing 6 along the central axis direction, and the bushing 7 (7') is fixed to the motor housing 6 (refer to Fig.10 and 11 ).

[0090] At this time, the dividing surface 7D (see Fig. 9 (a)) is arranged parallel to the central axis direction of the motor housing 6, and the outer side surface of the bushing 7 is held by the side wall of the groove portion 64. Thus, it is possible to prevent the bushing 7 from being torn from the dividing surface 7D when or after being mounted to the motor housing 6.

[0091] Furthermore, the bushing 7 is mounted such that the hinge portion 73 is arranged in the direction of fitting with the motor housing 6 (the output side of the electric motor 1 ). Thus, when the bushing 7 is fitted in the motor housing 6 , the bushing 7 is prevented from opening from the dividing surface 7D.

[0092] As described above, in this embodiment, the angle limiting portion 74 (limiting surfaces 714C, 714D, flange connecting portion 714E) is provided as a stopper (angle limiting portion) on the bushing 7, 7', and limits the opening angle of the bushing 7 installed on the motor housing 6, thereby reducing the load acting on the hinge portion 73 and preventing damage to the bushing 7.

[0093] (Number Description)

[0094] 1 Permanent Magnet Motor

[0095] 2 Stator

[0096] 21 stator core

[0097] 22 Insulation

[0098] 23 Winding

[0099] 3 Rotor

[0100] 31. Permanent magnet

[0101] 311 Permanent magnet sheet

[0102] 32 Outer core

[0103] 33 Insulation components

[0104] 34 Inner core

[0105] 343 Through hole

[0106] 35 Axis

[0107] 42 Second bearing

[0108] 52 Second bracket

[0109] 6 Motor housing (shell)

[0110] 64 Groove

[0111] 641 Wall

[0112] 642 Hole

[0113] 643 Waterproof wall

[0114] 7 Bushing

[0115] 71 Installation

[0116] 711, 712 flange

[0117] 714A, 714B Notch

[0118] 714C, 714D Notched surface (restricted surface)

[0119] 714E Flange connection

[0120] 72 Wiring through section

[0121] 7A, 7B First retaining piece, second retaining piece

[0122] 73 hinge

[0123] 74 Angle limiter (stopper)

[0124] 81 Heat conducting components

[0125] 82 Circuit board

[0126] 821 Electronic components

[0127] O Center axis.

Claims

1. An electric motor comprising: a stator having a stator core and a winding; a motor housing covering the stator; a circuit board arranged in the motor housing; and a bushing mounted on the motor housing and holding wiring led from the circuit board to the outside of the motor housing, The bushing has a first retaining piece, a second retaining piece and a hinge portion, The hinge portion connects one end of the first retaining piece and one end of the second retaining piece to each other, and the hinge portion is integrally formed as a thin wall between the first retaining piece and the second retaining piece, and the hinge portion opens and closes in a direction that brings the other end of the first retaining piece and the other end of the second retaining piece closer to or farther from each other along a circumferential direction in which the wiring is led out through the bushing, The first holding piece and the second holding piece are respectively provided with an angle limiting portion, and the angle limiting portion limits the opening angle of the hinge portion. The angle limiting portion includes a flange portion of the first retaining piece and a flange portion of the second retaining piece, wherein the flange portion of the first retaining piece is disposed on one end side of the first retaining piece, and the flange portion of the second retaining piece is disposed on one end side of the second retaining piece, and when the bushing is opened, the flange portion of the second retaining piece abuts against the flange portion of the first retaining piece, When the bush is in a fully opened state, the opening angle is limited to be not less than 45 degrees and not more than 135 degrees.

2. The electric motor according to claim 1, wherein: The flange portion of the first retaining piece has a first notch portion on the side close to the flange portion of the second retaining piece, The flange portion of the second retaining piece has a second notch portion, which is arranged on the side close to the flange portion of the first retaining piece. When the other end of the first retaining piece and the other end of the second retaining piece are away from each other, the second notch portion abuts against the first notch portion.

3. The electric motor according to claim 1 or 2, wherein: The motor housing has a groove portion provided at an end portion of the motor housing in a central axis direction.

4. The electric motor according to claim 3, wherein: The bushing is engaged with the groove portion, The groove portion has a wall portion that faces the flange portion of the first holding piece and the flange portion of the second holding piece in the direction in which the wiring is led out.

5. The electric motor according to claim 3, wherein: In the first holding piece and the second holding piece, the dividing surfaces are arranged parallel to the central axis direction of the motor housing, and the outer side surface of the bushing is held by the side wall of the groove portion.

6. The electric motor according to claim 3, wherein: The bushing is mounted so that the hinge portion is arranged on the bottom surface side of the groove portion provided in the motor housing.

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