WO2020195393A1

WO2020195393A1 - Motor

Info

Publication number: WO2020195393A1
Application number: PCT/JP2020/006700
Authority: WO
Inventors: 尚石田; 梅田　智之; 裕也齋藤; 藤原　英雄
Original assignee: 日本電産株式会社
Priority date: 2019-03-28
Filing date: 2020-02-20
Publication date: 2020-10-01
Also published as: CN113439381A

Abstract

One embodiment of a motor according to this invention comprises: a rotor which rotates about a central axis; a stator which faces the rotor in the radial direction; a housing which is made from resin and in which the stator is embedded; and a fastening fixture which is embedded in the housing and to which a fastening member is fastened. The fastening fixture has an exposed end portion which is exposed to the exterior from the housing.

Description

motor

The present invention relates to a motor.

In recent years, motors in which the stator is molded with resin have been developed for the purpose of simplifying the assembly process. In the motor of Patent Document 1, the resin portion that molds the stator constitutes the housing.

Japanese Publication: Japanese Patent Application Laid-Open No. 2010-22191

The housing of Patent Document 1 is provided with a hole for attaching the motor to the device to be attached. The motor can be attached to the device by inserting a fastening member into the hole. In such a fastening structure, when an attempt is made to increase the fastening strength, there is a risk that the resin portion may crack due to the stress generated during fastening.

In view of the above circumstances, one of the objects of the present invention is to provide a motor capable of simplifying the assembly process by molding the stator with a resin material and increasing the fastening strength with an external device.

One aspect of the motor of the present invention is a rotor that rotates around a central axis, a stator that faces the rotor in the radial direction, a housing that is made of resin and in which the stator is embedded, and a fastening member that is embedded in the housing. A tool to be fastened is provided. The fastener to be fastened has an exposed end exposed to the outside from the housing.

According to one aspect of the present invention, there is provided a motor capable of simplifying the assembly process and increasing the fastening strength with an external device by molding the stator with a resin material.

FIG. 1 is a cross-sectional view of the motor of one embodiment. FIG. 2 is a plan view of the motor of one embodiment. FIG. 3 is a partial cross-sectional view of a mold for molding the housing of one embodiment. FIG. 4 is a perspective view of the insert nut of one embodiment. FIG. 5 is a cross-sectional view of the insert nut of the modified example 1. FIG. 6 is a cross-sectional view of the insert nut of the modified example 2. FIG. 7 is a plan view of the insert nut of the modified example 3. FIG. 8 is a cross-sectional view of the insert nut of the modified example 3 along the line VIII-VIII of FIG.

Hereinafter, embodiments to which the present invention has been applied will be described in detail with reference to the drawings.
In the following description, the direction parallel to the central axis J (see FIG. 1) is simply referred to as "axial direction" or "vertical direction", and the radial direction centered on the central axis J is simply referred to as "radial direction". The circumferential direction around the axis J, that is, the circumference of the central axis J is simply referred to as the "circumferential direction". Further, in the present specification, one side in the axial direction along the central axis J is simply referred to as "upper side", and the other side is simply referred to as "lower side". It should be noted that the vertical direction in the present specification is merely a direction used for explanation, and does not limit the posture during use and distribution of the motor.

FIG. 1 is a cross-sectional view of the motor 1 of one embodiment. FIG. 2 is a plan view of the motor 1. Note that the rotor 10 is not shown in FIG.

As shown by a virtual line (dashed line) in FIG. 1, the motor 1 is attached to an external device 9 arranged on the upper side of the motor 1 by using a fixing bolt (fastening member) 9e. The motor 1 transmits power to the external device 9.
The motor 1 includes a rotor 10, a stator 20 surrounding the rotor 10, an upper bearing 15 and a lower bearing 16 that rotatably hold the rotor 10, an upper bearing holder 40 that holds the upper bearing 15, and a lower bearing 16. It has a lower bearing holder 70 for holding the bearing, a housing 30, a plurality of insert nuts (fastened fasteners) 50, and a plurality of bus bars 80.

The rotor 10 rotates about a central axis J extending in the vertical direction. The rotor 10 has a shaft 11 extending along the central axis J, a rotor core 12, and a rotor magnet 13.

The shaft 11 is connected to the power transmission mechanism 9d of the external device 9 at the upper end portion (the end portion on one side in the axial direction). The shaft 11 is rotatably supported around the central axis J by the upper bearing 15. The rotor core 12 is fixed to the outer peripheral surface of the shaft 11. Further, the rotor magnet 13 is fixed to the outer peripheral surface of the rotor core 12. The plurality of rotor magnets 13 may be embedded inside the rotor core 12.

The upper bearing 15 is located above the stator 20, and the lower bearing 16 is located below the stator 20. The upper bearing 15 supports the upper end of the shaft 11, and the lower bearing 16 supports the lower end of the shaft 11. The upper bearing 15 and the lower bearing 16 of the present embodiment are ball bearings. However, the upper bearing 15 and the lower bearing 16 may be other types of bearings such as needle bearings.

The upper bearing holder 40 is located above the stator 20. The upper bearing holder 40 is made of metal. The upper bearing holder 40 has a holder cylinder portion 41, an upper plate portion 42 extending radially inward from the upper end of the holder cylinder portion 41, and a holder flange portion 43 extending radially outward from the lower end of the holder cylinder portion 41. ..

The holder cylinder portion 41 has a cylindrical shape centered on the central axis J. The upper bearing 15 is arranged inside the holder cylinder portion 41 in the radial direction. The upper plate portion 42 covers the upper side of the outer ring of the upper bearing 15. The upper plate portion 42 is provided with a central hole 42a penetrating in the axial direction. The shaft 11 is inserted through the central hole 42a. The radial outer end of the holder flange portion 43 is embedded in the housing 30. That is, at least a part of the upper bearing holder 40 is embedded in the housing 30.

The lower bearing holder 70 is located below the stator 20. The lower bearing holder 70 is made of resin. The lower bearing holder 70 has a disk shape when viewed from the axial direction. The lower bearing holder 70 is fixed to the housing 30 at the outer edge.

A central hole 72a is provided in the center of the lower bearing holder 70 when viewed from the axial direction. The lower end of the shaft 11 is inserted into the central hole 72a. An inner wall surface 71a that surrounds the lower bearing 16 from the outside in the radial direction and holds the lower bearing 16 is provided around the central hole 72a.

The stator 20 surrounds the rotor 10 from the outside in the radial direction. The stator 20 faces the rotor 10 in the radial direction. The stator 20 includes a stator core 21, an insulator 22, and a coil 29.

The stator core 21 has an annular core back portion 21a centered on the central axis J and a plurality of teeth portions 21b extending radially inward from the core back portion 21a. A plurality of tooth portions 21b are provided at equal intervals in the circumferential direction around the central axis J.

The coil 29 is attached to the teeth portion 21b via the insulator 22. The end of the coil 29 is connected to a bus bar 80 located below the stator 20. The bus bar 80 is connected to a control device (not shown). Electric power is supplied to the coil 29 from the control device via the bus bar 80.

The housing 30 is made of a resin material. In the present specification, the resin material may be a composite material reinforced with a fiber material such as glass fiber or carbon fiber. That is, the housing 30 may be a fiber reinforced resin material.

A stator 20, a bus bar 80, an upper bearing holder 40, and an insert nut 50 are embedded in the housing 30. As a result, the housing 30 holds the bus bar 80, the stator 20, the upper bearing holder 40, and the insert nut 50. The housing 30 is manufactured by insert molding while holding the stator 20, the bus bar 80, the upper bearing holder 40, and the insert nut 50 in the mold. According to the present embodiment, since the housing 30 embeds the stator 20, the bus bar 80, the upper bearing holder 40, and the insert nut 50, the assembly process of each member can be simplified.

The housing 30 extends downward from the lower surface of the main body 31 holding the stator 20, the protruding portion 3 protruding upward from the upper surface of the main body 31, the bus bar holder 36 holding the bus bar 80, and the lower surface of the main body 31. It has a lower cylinder portion 37, a plurality of flange portions 39 projecting radially outward from the main body portion 31, and a holder holding portion 38 for holding the upper bearing holder 40. The protruding portion 3 is a general term including an annular rib 3A and a radial rib 35. Further, the annular rib 3A is a general term including an inner annular rib 32, an intermediate annular rib 33, and an outer annular rib 34.

The stator 20 is embedded in the main body 31. The main body 31 surrounds the upper side, the lower side, and the radial outer side with respect to the stator 20. The main body 31 surrounds the teeth portion 21b and the coil 29, and is also provided between the teeth portions 21b and the coil 29 that are adjacent to each other in the circumferential direction. Further, the main body 31 does not cover the inner peripheral surface of the stator core 21. Therefore, the inner peripheral surface of the stator core 21 is exposed from the housing 30.

The main body 31 has a plurality of openings 6. That is, the housing 30 has a plurality of openings 6. The plurality of openings 6 are traces of a support portion that supports the stator 20 in the mold when the housing 30 is molded. The plurality of openings 6 is a general term including a plurality of first openings 61, a plurality of second openings 62, and a plurality of third openings 63.

As shown in FIG. 2, the protruding portion 3 is a general term for a plurality of ribs protruding upward from the upper surface of the main body portion 31. The protrusion 3 is located above the stator 20. The protrusion 3 has a plurality of annular ribs 3A extending along the circumferential direction and a plurality of radial ribs 35 extending along the radial direction and connecting to the annular ribs 3A. Since the housing 30 has an annular rib 3A and a radial rib 35 that are connected to each other, the strength in the radial direction and the circumferential direction is enhanced in a well-balanced manner.

Each of the plurality of annular ribs 3A has a cylindrical shape centered on the central axis J. The plurality of annular ribs 3A include an inner annular rib 32 having the smallest diameter, an intermediate annular rib 33 located between the inner annular rib 32 and the outer annular rib 34 in the radial direction, and an outer annular rib 34 having the largest diameter. , Have. The inner annular rib 32, the intermediate annular rib 33, and the outer annular rib 34 are provided concentrically with the central axis J as the center.

The plurality of radial ribs 35 extend radially with respect to the central axis J. The plurality of radial ribs 35 are arranged at equal intervals along the circumferential direction. The housing 30 of the present embodiment is provided with six radial ribs 35. The plurality of radial ribs 35 connect the inner annular rib 32, the intermediate annular rib 33, and the outer annular rib 34, respectively. Further, the plurality of radial ribs 35 intersect and connect with the intermediate annular rib 33. By connecting the plurality of concentric annular ribs 3A to each other by the plurality of radial ribs 35, the strength in the circumferential direction and the radial direction of the housing 30 can be increased.

As shown in FIG. 1, the inner annular rib 32 has an annular portion 32a attached to the external device 9. The annular portion 32a is located at the upper end of the inner annular rib 32. The annular portion 32a is a portion of the inner annular rib 32 located above the upper end surface of the other ribs (intermediate annular rib 33, outer annular rib 34, and radial rib 35). In the axial direction, the positions of the upper end surfaces of the other ribs (that is, the intermediate annular rib 33, the outer annular rib 34, and the radial rib 35) coincide with each other. The annular portion 32a has a cylindrical shape extending upward from the upward facing surface of the housing 30.

The annular portion 32a is located on the radial outside of the first opening 61. The annular portion 32a is located radially inside the outer peripheral surface of the housing 30. The annular portion 32a is attached to the external device 9 and plays a part of the sealing function of the motor 1.

The external device 9 has a cylindrical holding cylinder portion 9a centered on the central axis J. The holding cylinder portion 9a surrounds the annular portion 32a from the outside in the radial direction. The inner diameter of the holding cylinder portion 9a is slightly larger than the outer diameter of the annular portion 32a. The tip surface of the holding cylinder portion 9a comes into contact with the upper end surface of the radial rib 35.

A concave groove 9b extending along the circumferential direction is provided on the inner peripheral surface of the holding cylinder portion 9a. The sealing member 9c is housed in the groove 9b. The sealing member 9c is made of an elastic material such as rubber. The seal member 9c extends along the circumferential direction. In this embodiment, the seal member 9c is an O-ring. The seal member 9c is not limited to a member having a circular cross-sectional shape as long as it functions as a gasket.

The seal member 9c is sandwiched between the outer peripheral surface 32d of the annular portion 32a facing outward in the radial direction and the bottom surface of the concave groove 9b facing outward in the radial direction. By compressing the seal member 9c, it is possible to prevent moisture from entering the inside of the holding cylinder portion 9a.

The bus bar holder portion 36 is located on the lower surface of the main body portion 31. The housing 30 of the present embodiment is provided with two bus bar holder portions 36. Three bus bars 80 are embedded inside each bus bar holder portion 36. The bus bar 80 projects downward from the lower surface of the bus bar holder portion 36.

The lower cylinder portion 37 has a cylindrical shape centered on the central axis J. The outer peripheral surface of the lower cylinder portion 37 is continuous with the outer peripheral surface of the main body portion 31. The lower cylinder portion 37 surrounds the lower end portions of the plurality of bus bars 80 protruding from the housing 30 from the outside in the radial direction. Further, the lower cylinder portion 37 surrounds the plurality of second openings 62 and the plurality of third openings 63 from the outside in the radial direction.

A control device (not shown) for controlling the motor 1 is attached to the lower cylinder portion 37. Further, the bus bar 80 is connected to a socket portion (not shown) provided in the control device. The inner peripheral surface of the lower cylinder portion 37 and the control device are sealed by a seal structure (not shown). According to the present embodiment, the lower cylinder portion 37 having a sealing function surrounds the plurality of second openings 62 and the plurality of third openings 63 from the outside in the radial direction. Therefore, it is possible to prevent water from reaching the second opening 62 and the third opening 63.

The flange portion 39 is provided on the outer peripheral surface of the outer annular rib 34 and the main body portion 31. The upper end surface of the flange portion 39 is continuous with the upper end surface of the outer annular rib 34. A metal insert nut 50 is embedded in each of the plurality of flange portions 39. As a result, the housing 30 holds the insert nut 50. A fixing bolt 9e for fixing the motor 1 to the external device 9 is fastened to the insert nut 50.

As shown in FIG. 2, the housing 30 of the present embodiment is provided with three flange portions 39. The three flange portions 39 are arranged at equal intervals along the circumferential direction. One insert nut 50 is embedded in each of the three flange portions 39. In the present embodiment, the plurality of flange portions 39 are arranged discretely along the circumferential direction, but the present embodiment is not limited to this embodiment. For example, a plurality of insert nuts 50 may be embedded in a flange portion extending radially outward from the main body portion 31 in a flange shape.

As shown in FIG. 1, the insert nut 50 is a columnar shape extending along the center line J2. The center line J2 of the insert nut 50 is parallel to the center axis J of the motor 1. The insert nut 50 includes an upper end surface (first end surface) 50a facing upward, a lower end surface (second end surface) 50b facing downward, and an outer peripheral surface (contact portion) 50c facing radially outward of the center line J2. Has.

As shown in FIG. 1, the external device 9 has a plate-shaped fixing plate portion 9f extending radially outward from the lower end portion of the holding cylinder portion 9a. The external device 9 of the present embodiment has the same number of fixing plate portions 9f as the insert nuts 50 (three in the present embodiment). Each fixing plate portion 9f has a fixing hole 9g penetrating in the axial direction. A fixing bolt 9e is inserted into the fixing hole 9g from above. The motor 1 is fixed to the external device 9 by fastening the fixing bolt 9e to the screw hole 51 of the insert nut 50.

According to this embodiment, the insert nut 50 is embedded in the housing 30. The motor 1 is fixed to the external device 9 with the insert nut 50. Since there are no restrictions on the material of the insert nut 50, a material having higher strength than the resin material used for the housing 30 (a metal material in this embodiment) can be used. That is, the insert nut 50 has a higher strength than the housing 30. Therefore, as compared with the case where the external device 9 is directly fixed to the resin housing 30, it is possible to prevent the housing 30 from being cracked due to the stress applied at the time of fastening or the stress input due to the use of vibration or the like. be able to. Therefore, the fastening strength between the motor 1 and the housing 30 can be increased. Further, by increasing the fastening strength by one fixing bolt 9e, it is possible to reduce the number of fixing bolts 9e for obtaining a desired fixing strength, and it is possible to simplify the process of fixing the motor 1 to the external device 9. ..

The upper end surface 50a of the insert nut 50 is arranged on the same plane as the upper end surface of the flange portion 39. The lower end surface 50b of the insert nut 50 is arranged on the same plane as the lower end surface of the flange portion 39. The upper end surface 50a and the lower end surface 50b of the insert nut 50 are each exposed from the housing 30. On the other hand, the outer peripheral surface 50c of the insert nut 50 is located inside the housing 30. That is, the outer peripheral surface 50c comes into contact with the housing 30.

The insert nut 50 has a screw hole (tightened hole) 51 that opens in the upper end surface 50a and extends downward, and a positioning hole 52 that opens in the lower end surface 50b and extends upward. That is, the screw hole 51 and the positioning hole 52 are opened on opposite sides in the axial direction. Both the screw hole 51 and the positioning hole 52 extend in the axial direction about the center line J2. Further, the insert nut 50 has a partition wall 53 for partitioning the screw hole 51 and the positioning hole 52. The partition wall 53 is orthogonal to the center line J2.

The screw hole 51 opens upward. The inner peripheral surface of the screw hole 51 is exposed from the housing 30. A female screw is cut on the inner peripheral surface of the screw hole 51. The shaft portion of the fixing bolt 9e is inserted into the screw hole 51.

The positioning hole 52 opens downward. The positioning hole 52 is circular when viewed from the axial direction. The inner peripheral surface of the positioning hole 52 is exposed from the housing 30. A positioning pin provided in the mold 90 is inserted into the positioning hole 52 in the molding process of the housing 30. That is, the positioning hole 52 is used for positioning the insert nut 50 in the mold 90.

FIG. 3 is a partial cross-sectional view showing a holding state of the insert nut 50 in the mold 90 for molding the housing 30.
Inside the mold 90, a cavity C filled with a resin material constituting the housing 30 is provided. The mold 90 has a first mold 91 and a second mold 92 that surround the cavity C. The first type 91 and the second type 92 are relatively separable vertically on the parting line PL. The parting line PL is located, for example, on the same plane as the lower end surface 50b of the insert nut 50.

The first type 91 has a first surface 91f facing downward. In addition, the second type 92 has a second surface 92f facing upward. The first surface 91f and the second surface 92f face each other in the axial direction via the cavity C. The first surface 91f comes into contact with the upper end surface 50a of the insert nut 50. The second surface 92f comes into contact with the lower end surface 50b of the insert nut 50. The insert nut 50 is sandwiched between the first surface 91f and the second surface 92f of the mold 90 from above and below.

According to this embodiment, the insert nut 50 is sandwiched between the mold 90 at the upper end surface 50a and the lower end surface 50b. On the surface of the insert nut 50, the region in contact with the mold 90 is exposed from the housing 30. Therefore, the upper end surface 50a and the lower end surface 50b of the insert nut 50 are exposed end portions exposed to the outside from the housing 30. The insert nut 50 is axially positioned in the mold 90 at the exposed ends (upper end surface 50a and lower end surface 50b). Therefore, according to the present embodiment, the positioning accuracy of the insert nut 50 with respect to the housing 30 can be improved.

According to the present embodiment, since the insert nut 50 is sandwiched from above and below by the mold 90, the upper end surface 50a and the lower end surface 50b of the insert nut 50 are exposed surfaces. By sandwiching the insert nut 50 from above and below by the mold 90, the holding strength of the insert nut 50 in the mold 90 can be increased. Therefore, during molding, the position shift of the insert nut 50 due to the injection pressure of the resin is suppressed.

According to this embodiment, the upper end surface 50a through which the screw hole 51 opens comes into contact with the first surface 91f of the mold 90. That is, in the mold 90, the opening of the screw hole 51 is covered by the first surface 91f. Therefore, when the resin is injected into the mold 90, the resin material is suppressed from entering the screw holes 51.

As shown in FIG. 3, the mold 90 has a positioning pin 90p protruding upward from the second surface 92f. The positioning pin 90p is a columnar shape extending along the center line J2. The diameter of the positioning pin 90p is slightly smaller than the diameter of the positioning hole 52. The positioning pin 90p is inserted into the positioning hole 52. The positioning pin 90p fits into the positioning hole 52.

According to this embodiment, the insert nut 50 has a screw hole 51 to which the fixing bolt 9e is fastened. Since a female screw is provided on the inner peripheral surface of the screw hole 51, it is difficult to secure sufficient positioning accuracy when the inner peripheral surface of the screw hole 51 is used as a reference for positioning the insert nut 50. The insert nut 50 of the present embodiment has a positioning hole 52 in addition to the screw hole 51. By inserting the positioning pin 90p of the mold 90 into the positioning hole 52, the insert nut 50 can be positioned in the mold 90 in the radial direction of the center line J2. As a result, the positioning accuracy of the insert nut 50 with respect to the housing 30 can be improved.

According to this embodiment, the screw hole 51 and the positioning hole 52 are arranged coaxially. Therefore, by positioning the insert nut 50 with reference to the positioning hole 52, the positioning accuracy of the screw hole 51 with respect to the housing 30 can be easily improved. Further, according to the present embodiment, the insert nut 50 can be easily miniaturized as compared with the case where the screw hole 51 and the positioning hole 52 are not arranged coaxially. In addition, according to the present embodiment, the insert nut 50 can be manufactured at low cost by using a lathe or the like.

FIG. 4 is a perspective view of the insert nut 50.
The insert nut 50 has a concave groove 54 and an uneven portion (rotation stopper portion, retaining portion) 55 on the outer peripheral surface 50c. The concave groove 54 extends along the circumferential direction of the center line J2. The uneven portion 55 is formed by, for example, knurling. The uneven portion 55 has a concave-convex shape along the circumferential direction and also a concave-convex shape along the axial direction. Since the insert nut 50 is embedded in the housing 30, the housing 30 comes into contact with the surface of the uneven portion 55 of the concave groove 54.

According to the present embodiment, the concavo-convex portion 55 in which the concavo-convex shape is regularly arranged along the circumferential direction functions as a rotation stop portion. That is, when the housing 30 is inserted between the uneven shapes of the uneven portion 55, the insert nut 50 is fixed to the housing 30 in the circumferential direction around the center line J2 by the anchor effect.
Similarly, according to the present embodiment, the uneven portion 55 in which the uneven shapes are regularly arranged along the axial direction functions as a retaining portion. That is, when the housing 30 is inserted between the uneven shapes of the uneven portion 55, the insert nut 50 is fixed in the axial direction with respect to the housing 30 by the anchor effect. Further, a part of the housing 30 enters the inside of the concave groove 54. Therefore, the concave groove 54 functions as a retaining portion together with the uneven portion 55.
The uneven portion 55 may be at least one of convex and concave with respect to the housing 30 in order to function as a rotation stopper and a retaining portion. Further, in the uneven portion 55, the uneven shapes are regularly arranged in the circumferential direction and the axial direction, but the positions where the uneven shapes are arranged are irregular, and the height or depth of the uneven shapes is irregular. It may be.

Hereinafter, modifications of the above-described embodiment will be described. In the following description of the modified example, the points changed from the above-described embodiment will be mainly described, and the same reference numerals will be given to the components having the same embodiment as the above-described embodiment, and the description thereof will be omitted.
<Modification example 1>
FIG. 5 is a cross-sectional view of the insert nut 150 of the first modification. Hereinafter, the insert nut 150 of the first modification will be described with reference to FIG. The insert nut 150 of this modification is mainly different in the configuration of the screw hole 151 and the positioning hole 152 as compared with the above-described embodiment.

Similar to the above embodiment, the insert nut 150 is embedded in the flange portion 39 of the housing 30. The insert nut 150 of this modification functions as an exposed end portion where at least the upper end surface 150a is exposed from the housing 30.

The insert nut 150 has a screw hole (fastened hole) 151 that opens in the upper end surface 150a and a positioning hole 152 that opens in the bottom of the screw hole 151. That is, the screw hole 151 and the positioning hole 152 are opened in the same direction in the axial direction. Both the screw hole 151 and the positioning hole 152 extend in the axial direction about the center line J2. The diameter of the positioning hole 152 is smaller than the inner diameter of the female screw of the screw hole 151. When viewed from the axial direction, the entire positioning hole 152 is located inside the screw hole 151. Here, the inside of the screw hole 151 means the inside of the inner diameter of the female screw of the screw hole.

A female screw is provided on the inner peripheral surface of the screw hole 151. The shaft portion of the fixing bolt 9e is inserted into the screw hole 151. A positioning pin provided in the mold 90 is inserted into the positioning hole 152 in the molding process of the housing 30. The insert nut 150 of this modification is adopted in place of the insert nut 50, for example, in the motor 1 of the above-described embodiment.

<Modification 2>
FIG. 6 is a cross-sectional view of the insert nut 250 of the modified example 2. Hereinafter, the insert nut 250 of the second modification will be described with reference to FIG. The insert nut 250 of the present modification is mainly different in the configuration of the screw hole 251 and the positioning hole 252 as compared with the above-described embodiment.

Similar to the above embodiment, the insert nut 250 is embedded in the flange portion 39 of the housing 30. The insert nut 250 of this modification functions as an exposed end portion where at least the upper end surface 250a is exposed from the housing 30.

The insert nut 250 has a positioning hole 252 that opens in the upper end surface 250a and a screw hole (fastened hole) 251 that opens in the bottom of the screw hole 251. That is, the screw hole 251 and the positioning hole 252 are opened in the same direction in the axial direction. Both the screw hole 251 and the positioning hole 252 extend in the axial direction about the center line J2. The diameter of the positioning hole 252 is larger than the diameter of the female thread valley of the screw hole 251. When viewed from the axial direction, the entire screw hole 251 is located inside the positioning hole 252. Here, the entire screw hole 251 means a region inside the diameter of the female screw valley of the screw hole 251 when viewed from the axial direction.

A female screw is provided on the inner peripheral surface of the screw hole 251. The shaft portion of the fixing bolt 9e is inserted into the screw hole 251. A positioning pin provided in the mold 90 is inserted into the positioning hole 252 in the molding process of the housing 30. The insert nut 250 of this modification is adopted in place of the insert nut 50, for example, in the motor 1 of the above-described embodiment.

<Modification example 3>
FIG. 7 is a plan view of the insert nut 350 of the modified example 3. FIG. 8 is a cross-sectional view of the insert nut 350 of the modified example 3 along the line VIII-VIII of FIG. Hereinafter, the insert nut 350 of the modified example 3 will be described with reference to FIG. The insert nut 350 of this modification is mainly different in the configuration of the positioning groove 352 as compared with the above-described embodiment.

Similar to the above embodiment, the insert nut 350 is embedded in the flange portion 39 of the housing 30. The insert nut 350 of this modification functions as an exposed end portion where the upper end surface 350a and the lower end surface 350b are exposed from the housing 30.

The insert nut 350 has a screw hole (to be fastened) 351 that opens in the upper end surface 350a and a positioning groove 352 that opens in the outer peripheral surface 350c and extends along the axial direction. A female screw is provided on the inner peripheral surface of the screw hole 351. The shaft portion of the fixing bolt 9e is inserted into the screw hole 351.

The positioning groove 352 is exposed from the outer peripheral surface of the flange portion 39. A positioning rib (not shown) provided in the mold is inserted into the positioning groove 352 in the molding process of the housing 30. As a result, the insert nut 350 is positioned with respect to the mold. The insert nut 350 of this modification is adopted in place of the insert nut 50, for example, in the motor 1 of the above-described embodiment.

Although one embodiment of the present invention and a modification thereof have been described above, each configuration and a combination thereof in the embodiment and the modified example are examples, and the configuration is added within a range not deviating from the gist of the present invention. , Omission, replacement and other changes are possible. Moreover, the present invention is not limited to the embodiments.

For example, the use of the motor unit of the above-described embodiment and its modified example is not particularly limited. The motor unit of the above-described embodiment and its modification is mounted on, for example, an electric pump, an electric power steering, and the like.

Further, in the above-described embodiment, the positioning hole is circular when viewed from the axial direction. However, if positioning can be performed with the positioning pin of the mold, the shape is not limited to the circular shape.

1 ... motor, 9e ... fixing bolt (fastening member), 10 ... rotor, 20 ... stator, 30 ... housing, 31 ... main body, 39 ... flange, 50 ... insert nut (fastened tool), 50a ... upper end surface ( 1st end face, exposed end), 50b ... Lower end surface (2nd end face, exposed end), 50c ... Outer surface (contact part), 51,151,251,351 ... Screw hole (to be fastened), 52, 152, 252 ... Positioning hole, 53 ... Partition wall, 55 ... Concavo-convex part (rotation stop part, retaining part), 352 ... Positioning groove, J ... Central axis

Claims

A rotor that rotates around the central axis and
A stator facing the rotor in the radial direction and
A housing made of resin and in which the stator is embedded,
A tool to be fastened, which is embedded in the housing and to which a fastening member is fastened, is provided.
The fastener to be fastened is a motor having an exposed end portion exposed to the outside from the housing.
The motor according to claim 1, wherein the housing has a main body portion in which the stator is embedded and a flange portion that protrudes radially outward from the main body portion and in which the fastener to be fastened is embedded.
The motor according to claim 2, wherein the fastened tool has a first end surface on one side in the axial direction exposed from the housing and a second end surface on the other side in the axial direction exposed from the housing.
The fastener to be fastened has a hole to be fastened extending in the axial direction and a positioning hole extending in the axial direction.
The motor according to any one of claims 1 to 3.
The motor according to claim 4, wherein the positioning hole and the fastened hole are arranged coaxially.
The positioning hole and the to be fastened hole are opened on opposite sides in the axial direction.
The motor according to claim 4 or 5, wherein the fastened tool has a partition wall for partitioning the positioning hole and the fastened hole.
The positioning hole opens at the exposed end and
The fastened hole opens at the bottom of the positioning hole.
The motor according to claim 4 or 5.
The motor according to claim 7, wherein the entire hole to be fastened is located inside the positioning hole when viewed from the axial direction.
The to be fastened hole is opened at the exposed end portion,
The positioning hole opens at the bottom of the hole to be fastened.
The motor according to claim 4 or 5.
The motor according to claim 9, wherein the entire positioning hole is located inside the hole to be fastened when viewed from the axial direction.
The motor according to claim 1, wherein the tool to be fastened has a hole to be fastened extending along the axial direction and a positioning groove opening on the outer peripheral surface and extending along the axial direction.
The motor according to any one of claims 4 to 11, wherein the fastened hole is a screw hole into which a shaft portion of the fastening member, which is a bolt, is inserted.
The motor according to any one of claims 1 to 12, wherein the fastened tool has an uneven portion that is at least one convex or concave with respect to the housing at a contact portion that contacts the housing.
The motor according to claim 13, wherein the uneven portion is a rotation stop portion arranged along the circumferential direction.
The motor according to claim 13 or 14, wherein the uneven portion is a retaining portion arranged along the axial direction.
The motor according to any one of claims 1 to 15, wherein the fastened tool is made of metal.