CN113572301A - Electric motor - Google Patents

Abstract

A motor includes a motor main body having a rotor and a stator, a motor case accommodating the motor main body, and a shield wire drawn out to the outside of the motor case, wherein the appearance can be improved even if the shield wire is prevented from being drawn out when a tensile force acts on the shield wire. In the motor, a shield material (37) and an insulating coating (38) are removed to expose a central core wire exposed part (8a) of a central core wire (36) and a central core wire coating part (8b) of the central core wire (36) covered by the shield material (37) and the insulating coating (38) are formed on a shield wire (8), and a shield material fixing part (8c) where the shield material (37) is folded back and fixed on the outer peripheral surface of the insulating coating (38) on the side of the central core wire coating part (8b) is formed at the boundary part of the central core wire exposed part (8a) and the central core wire coating part (8 b). The motor housing is formed with a restricting portion (29d) for restricting the movement of the shielding material fixing portion (8c) to the outside of the motor housing.

Description

Electric motor

Technical Field

The present invention relates to a motor including a shield wire drawn out of a motor case.

Background

Conventionally, there is known an electric motor including: a motor main body having a rotor and a stator; and a motor housing accommodating the motor main body (see, for example, patent document 1). The motor described in patent document 1 includes an encoder for detecting a rotational speed and a rotational position of a rotor. The encoder includes: a sensor magnet mounted on the rotor; a magnetic induction element disposed opposite to the sensor magnet; and a sensor substrate on which the magnetic induction element is mounted. The sensor output line is connected to the sensor substrate. The sensor output line is, for example, a shielded line including a center core wire, a shielding material covering the center core wire, and an insulating film covering the shielding material.

In the motor described in patent document 1, a motor housing includes: a cylindrical housing; a first bearing holder disposed on the opposite side of the cylindrical housing from the output side; and a second bearing holder disposed on the output side of the cylindrical housing. An encoder cover for accommodating the encoder is mounted on the opposite side of the first bearing holder from the output side. The encoder cover is provided with a notch, and a gap is formed between the encoder cover and the first bearing holder through the notch. A bushing is interposed in the gap. The sensor output line is wound through the bushing, and the sensor output line passing through the bushing is led out to the outside in the radial direction of the motor.

In the motor described in patent document 1, a wiring fixing portion for fixing the sensor output line to the outside of the motor housing is formed in the first bearing holder, and the sensor output line drawn out to the outside of the encoder cover through the bush is fixed to the wiring fixing portion. In the motor described in patent document 1, the sensor output wire is fixed to the wire fixing portion, thereby preventing the sensor output wire from being pulled out when a pulling force for pulling out the sensor output wire acts on the sensor output wire. That is, in the motor described in patent document 1, the sensor output line is fixed to the wiring fixing portion, thereby preventing the connection portion between the sensor output line and the sensor substrate from being damaged when a tensile force acts on the sensor output line.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-9570

Disclosure of Invention

Technical problem to be solved by the invention

In the motor described in patent document 1, the sensor output line is fixed to a wiring fixing portion disposed outside the motor case, and the fixing portion of the sensor output line appears in the appearance of the motor. Therefore, in the case of the motor described in patent document 1, the appearance of the motor may be deteriorated.

Accordingly, an object of the present invention is to provide a motor including a motor main body portion having a rotor and a stator, a motor case accommodating the motor main body portion, and a shield wire drawn out to the outside of the motor case, the motor being capable of improving the appearance even if the shield wire is prevented from being drawn out when a tensile force acts on the shield wire.

Technical scheme for solving technical problem

In order to solve the above problem, the present invention provides a motor including: a motor main body portion having a rotor and a stator; a motor case that houses a motor main body portion; a detection mechanism housed in the motor case; and a shield wire which is led out from the detection mechanism to the outside of the motor case, the shield wire including a center core wire, a shield material covering the center core wire, and an insulating film covering the shield material, wherein the shield wire is formed with a shield material and an insulating film which are removed to expose the center core wire to a center core wire exposed portion and a center core wire covering portion covered with the shield material and the insulating film, a shield material fixing portion is formed at a boundary portion between the center core wire exposed portion and the center core wire covering portion, the shield material is folded and fixed to an outer peripheral surface of the insulating film on the center core wire covering portion side, the center core wire exposed portion and the shield material fixing portion are disposed inside the motor case, and a restriction portion for restricting the movement of the shield material fixing portion to the outside of the motor case is formed or attached to the motor case.

In the motor of the present invention, a shield fixing portion is formed at a boundary portion between the central-wire exposed portion and the central-wire covering portion of the shield wire, the shield of the shield fixing portion is folded and fixed to an outer peripheral surface of the insulating film on the central-wire covering portion side, and an outer diameter of the shield fixing portion is larger than an outer diameter of the central-wire covering portion. In the present invention, the restriction portion for restricting the movement of the shield fixing portion disposed inside the motor case to the outside of the motor case is formed or attached to the motor case. Therefore, in the present invention, the pulling-out of the shield wire when a tensile force acts on the shield wire can be prevented by the shield material fixing portion and the regulating portion.

In addition, in the present invention, since the shield fixing portion is disposed inside the motor case, the shield fixing portion having an outer diameter larger than that of the core wire covering portion does not appear in the appearance of the motor. Therefore, in the present invention, even if the pulling-out of the shield wire when the pulling force acts on the shield wire can be prevented, the appearance of the motor can be improved. In addition, in the present invention, since the shield material of the shield wire can be used to prevent the pull-out of the shield wire, the structure of the motor can be simplified.

In the present invention, it is preferable that the shielding material folded back to the outer peripheral surface of the insulating film in the shielding material fixing portion is twisted in the circumferential direction of the core wire covering portion. With this configuration, the outer diameter of the shield fixing portion can be increased as compared with a case where the shield material folded back to the outer peripheral surface of the insulating film is not twisted in the circumferential direction of the core wire covering portion. Therefore, the pulling-out of the shield wire when the pulling force acts on the shield wire can be effectively prevented.

In the present invention, it is preferable that the shield material folded back to the outer peripheral surface of the insulating film is fixed to the shield material fixing portion by an adhesive. With this configuration, the shield material folded back on the outer peripheral surface of the insulating film can be fixed relatively easily. In addition, if configured in this way, the shielding material folded back onto the outer peripheral surface of the insulating film can be covered with the adhesive, and therefore, the insulating property of the shielding material folded back onto the outer peripheral surface of the insulating film can be ensured using the adhesive.

In the present invention, it is preferable that the shield wire includes a covering member covering at least the shield material fixing portion, and the covering member is a heat-shrinkable tube which is heat-shrinkable. With this configuration, the outer diameter of the portion where the shield material fixing portion is formed can be increased by the covering member covering the shield material fixing portion. Therefore, the pulling-out of the shield wire when the pulling force acts on the shield wire can be effectively prevented. In addition, if the structure is such that the shield material fixing portion is covered with the covering member, the insulation of the shield material folded back to the outer peripheral surface of the insulating film can be ensured.

In the present invention, it is preferable that the motor includes a rubber bushing for preventing liquid from penetrating into the motor case, the bushing is attached to the motor case, an insertion hole through which the core wire covering portion is inserted is formed in the bushing, the covering member further covers a part of the core wire exposing portion side of the core wire covering portion, and a part of the core wire covering portion covered with the covering member is press-fitted into the insertion hole. With this configuration, the portion of the core wire covering portion covered with the covering member and the rubber bush can suppress the shield wire from being pushed in when a pushing force for pushing the shield wire into the motor case acts on the shield wire.

In the present invention, it is preferable that the covering member further covers a part of the center wire covering portion side of the center wire exposed portion. With this configuration, the insulation between the shield material and the core wire can be ensured by the covering member that covers a part of the core wire covering portion side of the core wire exposed portion. In addition, if configured in this way, the covering member covering the shield fixing portion can be prevented from falling off from the shield fixing portion.

In the present invention, it is preferable that the motor case includes a resin restriction portion forming member in which the restriction portion is formed. With such a configuration, for example, the movement of the shield fixing portion to the outside of the motor case can be reliably restricted, compared to the case where the movement of the shield fixing portion to the outside of the motor case is restricted using a rubber bush.

In the present invention, it is preferable that the motor includes a rubber bushing for preventing liquid from penetrating into the motor case, the bushing is formed with an insertion hole through which the core wire covering portion is inserted, the restricting portion forming member is formed with a bushing holding portion for holding the bushing, and the restricting portion constitutes a part of the bushing holding portion. With this configuration, the restricting portion constitutes a part of the bush holding portion, and therefore, the structure of the restricting portion forming member can be simplified.

In the present invention, it is preferable that the shielding material fixing portion has a front end of the shielding material folded back on the outer peripheral surface of the insulating film facing the outside of the motor case. That is, in the shield fixing portion, the tip of the shield folded back on the outer peripheral surface of the insulating film is preferably not directed toward the core wire exposed portion side. With this configuration, the contact between the leading end of the shield material and the core wire can be prevented. Therefore, it is easy to ensure insulation of the shield material and the core wire.

Effects of the invention

As described above, the present invention provides a motor including a motor main body having a rotor and a stator, a motor housing accommodating the motor main body, and a shield wire drawn out to the outside of the motor housing, which can improve the appearance of the motor even when the shield wire is prevented from being drawn out when a tensile force acts on the shield wire.

Drawings

Fig. 1 is a perspective view of a motor according to an embodiment of the present invention.

Fig. 2 is a sectional view of the motor shown in fig. 1.

Fig. 3 is a diagram for explaining the structure of the shielded line shown in fig. 1.

Fig. 4 is a perspective view of the shield wire, the cover, and the like shown in fig. 1.

Fig. 5 is an exploded perspective view of the cover, liner, and liner cover shown in fig. 4.

Fig. 6 is an exploded perspective view showing the cover, the bush, and the bush cover shown in fig. 5 from different directions.

Description of the reference numerals

1 … electric motor; 2 … rotor; 3 … stator; 4 … motor body portion; 5 … motor housing; 6 … detection mechanism; 8 … shielded wire; 8a … core wire exposed portion; 8b … core wire coating portion; 8c … shield material fixing part; 29 … cover (restricting portion forming member); 29b … bush holding part; 29d … supporting wall portions (restricting portions); 36 … core wire; 37 … shielding material; 38 … insulating film; 39 … adhesive; 40 … cladding the part; 43 … a bushing; 43a … is inserted through the hole.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

(integral Structure of Motor)

Fig. 1 is a perspective view of a motor 1 according to an embodiment of the present invention. Fig. 2 is a sectional view of the motor 1 shown in fig. 1.

The motor 1 of the present embodiment is an inner rotor type motor. The motor 1 includes: a motor main body 4 having a rotor 2 and a stator 3; a motor case 5 accommodating the motor main body portion 4; and a detection mechanism 6 for detecting the rotational speed and rotational position of the rotor 2. The motor 1 further includes a power supply line 7 for supplying power to the motor main body 4 and a shield line 8 connected to the detection mechanism 6.

The rotor 2 includes a rotating shaft 11 and a driving magnet 12 fixed to the rotating shaft 11. The output-side end of the rotary shaft 11 protrudes outside the motor housing 5. The stator 3 is disposed on the outer peripheral side of the driving magnet 12. The stator 3 includes a stator core 13 and a driving coil 15 wound around a salient pole of the stator core 13 via an insulator 14. The end of the driving coil 15 is wound around and fixed to a terminal pin fixed to the insulator 14, and a substrate 16 is soldered and fixed to the terminal pin. One end of the power supply line 7 is soldered and fixed to the substrate 16.

In the following description, the axial direction of the rotary shaft 11 (i.e., the axial direction of the rotor 2, the X direction in fig. 1, etc.) is referred to as the "front-rear direction", the Y direction in fig. 1, etc. orthogonal to the front-rear direction is referred to as the "left-right direction", and the Z direction in fig. 1, etc. orthogonal to the front-rear direction and the left-right direction is referred to as the "up-down direction". Further, an output side (X1 direction side in fig. 1 and the like) of the rotary shaft 11 in the front-rear direction (axial direction of the rotary shaft 11) is referred to as a "front" side, an opposite side (X2 direction side in fig. 1 and the like) to the output of the rotary shaft 11 in the front-rear direction is referred to as a "rear (back)" side, one side in the up-down direction, that is, a Z1 direction side in fig. 1 and the like is referred to as an "upper" side, and the other side in the up-down direction, that is, a Z2 direction side in fig. 1 and the like is referred to as a "lower" side.

The detection mechanism 6 is a magnetic rotary encoder. The detection mechanism 6 includes a detection magnet 20 and a flat plate-shaped substrate 21 disposed on the back side of the detection magnet 20. The substrate 21 is disposed such that the thickness direction of the substrate 21 coincides with the front-rear direction. A magnetoresistive element and a hall element are mounted on the front surface of the substrate 21. The detection magnet 20 is fixed to a magnet holder 22. The magnet holder 22 is fixed to the rear end portion of the rotary shaft 11. The substrate 21 is fixed to the substrate holder 23. The board holder 23 is fixed to a bearing holder 27, which will be described later, constituting the motor case 5.

The motor case 5 includes: a cylindrical case main body 25 that opens in the front-rear direction; a bearing holder 26 fixed to the front end of the housing body 25; a bearing holder 27 fixed to the rear end of the housing main body 25; a cover 28 covering a connection portion of the power supply line 7 and the substrate 16; and a cover 29 covering the detection mechanism 6. A bearing 30 for rotatably supporting the rotary shaft 11 is attached to the bearing holder 26. A bearing 31 for rotatably supporting the rotary shaft 11 is attached to the bearing holder 27.

The cover 28 is fixed to the upper surface of the housing main body 25. A rubber bush 32 for preventing liquid such as water from penetrating into the motor case 5 is attached between the cover 28 and the case main body 25. The bush 32 is formed with an insertion hole 32a through which the power supply line 7 is inserted. The power supply line 7 is drawn out from the insertion hole 32a to the outside of the motor case 5.

The cover 29 is fixed to the rear surface of the bearing holder 27. As described above, the cover 29 covers the detection mechanism 6, and the detection mechanism 6 is accommodated in the motor case 5. As described above, the shielded wire 8 is connected to the detection mechanism 6. Specifically, one end of the shield wire 8 is connected to the substrate 21 via the connector 33. The shielded wire 8 is led out from the detection mechanism 6 toward the outside of the motor case 5. Specifically, the shielded wire 8 is drawn out toward the outside of the cover 29. The structure of the shield wire 8 and the structure of the lead portion of the shield wire 8 will be described below.

(Structure of shielded wire and Structure of lead-out portion of shielded wire)

Fig. 3 is a diagram for explaining the structure of the shielded line 8 shown in fig. 1. Fig. 4 is a perspective view of the shield wire 8 and the cover 29 shown in fig. 1. Fig. 5 is an exploded perspective view of the cover 29, the bush 43, and the bush cover 44 shown in fig. 4. Fig. 6 is an exploded perspective view showing the cover 29, the bush 43, and the bush cover 44 shown in fig. 5 from a different direction.

The shielded wire 8 includes a center core 36, a shield material 37 covering the center core 36, and an insulating film 38 (see fig. 3) covering the shield material 37. The shield wire 8 of the present embodiment includes a plurality of core wires 36, and a shield material 37 covers the plurality of core wires 36. The core wire 36 is composed of a core wire (wire) composed of a copper wire or the like and an insulating coating covering the core wire. The shield material 37 is made of a copper wire or the like woven into a mesh shape. The shield line 8 has formed therein: a core wire exposure portion 8a in which the shielding material 37 and the insulating film 38 are removed to expose the core wire 36; and a core wire coating portion 8b in which the core wire 36 is coated with a shielding material 37 and an insulating coating 38. Specifically, both ends of the shield wire 8 are center-wire exposed portions 8a, and a portion of the shield wire 8 from which the center-wire exposed portions 8a are removed is a center-wire covering portion 8 b.

A shield fixing portion 8c is formed at a boundary portion between the central-core-wire exposed portion 8a and the central-core-wire covering portion 8b on one end side of the shield wire 8 (specifically, on the side of the shield wire 8 connected to the substrate 21), and a shield 37 is folded and fixed to an outer peripheral surface of the insulating film 38 on the central-core-wire covering portion 8b side (see fig. 3). In the shield fixing portion 8c, the shield 37 exposed to the outside with the insulating film 38 removed is once folded back toward the center wire covering portion 8b side and fixed, and the tip of the shield 37 folded back on the outer peripheral surface of the insulating film 38 is directed toward the center wire covering portion 8b side.

In the shield fixing portion 8c, the shield 37 folded back to the outer peripheral surface of the insulating film 38 is twisted in the circumferential direction of the core wire covering portion 8 b. In the shield fixing portion 8c, the shield 37 folded back to the outer peripheral surface of the insulating film 38 is fixed by an adhesive 39 (see fig. 3). That is, in the shield fixing portion 8c, the shield 37 folded back to the outer peripheral surface of the insulating film 38 is twisted in the circumferential direction of the core wire covering portion 8b, and then fixed by the adhesive 39. The adhesive 39 is applied so that the entire shielding material 37 folded back on the outer peripheral surface of the insulating film 38 is covered with the adhesive 39. The outer diameter of the shield material fixing portion 8c is larger than the outer diameter of the core wire covering portion 8 b.

The shield wire 8 includes a covering member 40 covering the shield material fixing portion 8 c. The covering member 40 also covers a part of the center wire covering portion 8b on the center wire exposed portion 8a side. The covering member 40 also covers a part of the core wire exposed portion 8a on the core wire covering portion 8b side. The sheathing member 40 is a heat-shrinkable tube that is heat-shrunk. The sheathing member 40 is formed by heating and shrinking a heat shrinkable tube before heat shrinkage from the outside in a state where the shielding material fixing portion 8c and the like have been inserted into the heat shrinkable tube. In fig. 4, the covering member 40 is not shown.

As described above, the shielded wires 8 are drawn out toward the outside of the cover 29. The cover 29 is formed of resin. The cover 29 is formed in a substantially square tubular shape with a bottom at the rear end. The cover 29 includes an upper wall portion 29a constituting an upper surface of the cover 29. A rubber bush 43 for preventing liquid from penetrating into the motor case 5 is attached to the cover 29. The bush 43 is formed with an insertion hole 43a penetrating the bush 43.

A bush holding portion 29b for holding the bush 43 is formed in the cover 29. The bush holding portion 29b is formed on the upper wall portion 29 a. The bush holding portion 29b is formed with a notch 29c in which the bush 43 is disposed. The notch 29c is cut in a U shape from the front end of the upper wall portion 29a toward the back side. Further, a support wall portion 29d that supports the bush 43 from below is formed in the bush holding portion 29 b. The support wall 29d is disposed below the notch 29 c. The support wall 29d is formed with a U-shaped notch 29 e. The notch 29e is cut out from the front end of the upper wall portion 29a toward the back side.

The outer shape of the notch 29e is smaller than that of the notch 29c, and as shown in fig. 6, the upper surface of the support wall 29d is a plane perpendicular to the vertical direction. As shown in fig. 5, the lower surface of the support wall 29d also becomes a plane perpendicular to the vertical direction. The width of the notch 29e in the left-right direction is smaller than the outer diameter of the shield material fixing portion 8 c. The width of the notch 29e in the left-right direction is larger than the outer diameter of the portion of the center-wire coating portion 8b covered with the coating member 40.

A liner cover 44 is fixed to the upper surface of the upper wall portion 29 a. The bush 43 is held by the bush holding portion 29b in a state of being sandwiched between the support wall portion 29d and the bush cover 44. In a state where the bush 43 is held by the bush holding portion 29b, the front surface of the bush 43 and the front surface of the cover 29 are arranged at the same position in the front-rear direction. In addition, the insertion hole 43a penetrates the bush 43 in the vertical direction in a state where the bush 43 is held by the bush holding portion 29 b. The bushing cover 44 is formed with an insertion hole 44a that penetrates the bushing cover 44 in the vertical direction.

The core wire exposed portion 8a constituting one end portion of the shield wire 8 (specifically, an end portion of the shield wire 8 on the side connected to the substrate 21) is disposed inside the cover 29. The shield material fixing portion 8c is disposed inside the cover 29. That is, the core wire exposure portion 8a and the shield material fixing portion 8c are disposed inside the motor case 5. The center wire coating portion 8b is inserted into the insertion hole 43a of the bush 43 and the insertion hole 44a of the bush cover 44, and the shield wire 8 is drawn out from the insertion holes 43a and 44a to the outside of the cover 29.

In the present embodiment, the portion of the core wire coating portion 8b covered with the coating member 40 is inserted into the insertion hole 43 a. Specifically, the portion of the core wire coating portion 8b covered with the covering member 40 is press-fitted into the insertion hole 43 a. The portion of the core wire covering portion 8b covered with the covering member 40 is disposed in the notch 29e and inserted into the insertion hole 44 a.

The shield material fixing portion 8c is disposed below the support wall portion 29 d. As described above, in the shield fixing portion 8c, the tip of the shield 37 folded back on the outer peripheral surface of the insulating film 38 faces the center wire coating portion 8b side, and therefore the tip of the shield 37 folded back on the outer peripheral surface of the insulating film 38 faces the outside of the cover 29. That is, the leading end of the shielding material 37 folded back to the outer peripheral surface of the insulating film 38 faces the outside of the motor case 5.

As described above, the portion of the core wire coating portion 8b covered with the covering member 40 is disposed in the notch 29 e. The width of the notch 29e in the left-right direction is smaller than the outer diameter of the shield material fixing portion 8 c. Therefore, the shield fixing portion 8c disposed below the support wall 29d is restricted from moving upward by the support wall 29 d. That is, in the present embodiment, the movement of the shield material fixing portion 8c to the outside of the cover 29 is restricted by the support wall portion 29 d.

The support wall 29d of the present embodiment is a regulating portion that regulates the movement of the shield fixing portion 8c to the outside of the motor case 5. That is, the restriction portion for restricting the movement of the shielding material fixing portion 8c to the outside of the motor case 5 is formed in the motor case 5. The support wall portion 29d as the restricting portion constitutes a part of the bush holding portion 29 b. The cover 29 of the present embodiment is a restricting portion forming member that forms the support wall portion 29d as the restricting portion.

(main effect of the present embodiment)

As described above, in the present embodiment, the shield fixing portion 8c is formed at the boundary portion between the central-wire exposed portion 8a and the central-wire covering portion 8b of the shield wire 8, and the outer diameter of the shield fixing portion 8c is larger than that of the central-wire covering portion 8 b. In the present embodiment, the movement of the shield fixing portion 8c disposed inside the cover 29 to the outside of the motor case 5 is restricted by the support wall portion 29d of the cover 29. Therefore, in the present embodiment, the shield wire 8 can be prevented from being pulled out when a tensile force acts on the shield wire 8 by the shield material fixing portion 8c and the support wall portion 29 d.

In the present embodiment, since the shield fixing portion 8c is disposed inside the motor case 5, the shield fixing portion 8c having an outer diameter larger than that of the core wire coating portion 8b does not appear in the appearance of the motor 1. Therefore, in the present embodiment, even if the shield wire 8 can be prevented from being pulled out when a pulling force is applied to the shield wire 8, the appearance of the motor 1 can be improved. In addition, in the present embodiment, since the shield material 37 of the shield wire 8 can prevent the shield wire 8 from being pulled out, the structure of the motor 1 can be simplified. In addition, in the present embodiment, since it is not necessary to form a wiring fixing portion on the bearing holder 27 as in the motor described in patent document 1, the structure of the bearing holder 27 can be simplified.

In the present embodiment, in the shield fixing portion 8c, the shield 37 folded back on the outer peripheral surface of the insulating film 38 is twisted in the circumferential direction of the core wire covering portion 8 b. Therefore, in the present embodiment, the outer diameter of the shield fixing portion 8c can be increased as compared with the case where the shield 37 folded back to the outer peripheral surface of the insulating film 38 is not twisted in the circumferential direction of the core wire covering portion 8 b. Therefore, in the present embodiment, the pulling-out of the shield wire 8 when the pulling force is applied to the shield wire 8 can be effectively prevented.

In particular, in the present embodiment, since the shield fixing portion 8c is covered with the covering member 40, the outer diameter of the portion where the shield fixing portion 8c is formed can be further increased. Therefore, in the present embodiment, the shield wire 8 can be more effectively prevented from being pulled out when a pulling force is applied to the shield wire 8.

In addition, in the present embodiment, since the movement of the shield fixing portion 8c to the outside of the motor case 5 is restricted by the support wall portion 29d of the resin cover 29, the movement of the shield fixing portion 8c to the outside of the motor case 5 can be reliably restricted, for example, compared to the case where the movement of the shield fixing portion 8c to the outside of the motor case 5 is restricted using the rubber bush 43.

In the present embodiment, the shield material 37 folded back on the outer peripheral surface of the insulating film 38 is fixed to the shield material fixing portion 8c by the adhesive 39. Therefore, in the present embodiment, the shield material 37 folded back on the outer peripheral surface of the insulating film 38 can be fixed relatively easily.

In the present embodiment, the entire shield material 37 folded back to the outer peripheral surface of the insulating film 38 in the shield material fixing portion 8c is covered with the adhesive 39. In the present embodiment, the covering member 40 also covers a part of the core wire exposed portion 8a on the core wire covering portion 8b side. Therefore, in the present embodiment, the insulating properties of the shield material 37 and the core wires 36 can be ensured by using the covering member 40 and the adhesive 39 that cover the core wire exposed portion 8 a.

In the present embodiment, the leading end of the shield material 37 folded back on the outer peripheral surface of the insulating film 38 faces the core wire covering portion 8b side but does not face the core wire exposing portion 8a side in the shield material fixing portion 8 c. Therefore, in the present embodiment, the contact of the leading end of the shield material 37 with the center wire 36 can be prevented. Therefore, in the present embodiment, it is easy to ensure the insulation of the shield material 37 and the core wire 36. In the present embodiment, since the shield fixing portion 8c is covered with the covering member 40, the insulating property of the shield fixing portion 8c can be reliably ensured by the covering member 40.

In the present embodiment, the portion of the cored wire coating portion 8b covered with the coating member 40 is pressed into the insertion hole 43a of the bush 43. Therefore, in the present embodiment, the pressing-in of the shielded wire 8 when a pressing-in force that presses the shielded wire 8 into the motor case 5 (specifically, into the cover 29) acts on the shielded wire 8 can be suppressed by the portion of the center wire coating portion 8b that is covered with the coating member 40 and the bush 43.

In the present embodiment, the covering member 40, which is a heat-shrinkable tube that is heat-shrinkable, covers a part of the central-wire exposed portion 8a side of the central-wire covering portion 8b and a part of the central-wire covering portion 8b side of the central-wire exposed portion 8a, in addition to the shield material fixing portion 8 c. In the present embodiment, the outer diameter of the core wire exposed portion 8a and the outer diameter of the core wire covered portion 8b are smaller than the outer diameter of the shield material fixing portion 8 c. Therefore, in the present embodiment, the covering member 40 covering the shield material fixing portion 8c can be prevented from coming off the shield material fixing portion 8 c.

In the present embodiment, the support wall portion 29d that restricts movement of the shield fixing portion 8c to the outside of the motor case 5 constitutes a part of the bush holding portion 29b that holds the bush 43. Therefore, in the present embodiment, the configuration of the cover 29 can be simplified as compared with a case where a restricting portion that restricts movement of the shielding material fixing portion 8c to the outside of the motor case 5 is formed in the cover 29 in addition to the bush holding portion 29 b.

(other embodiments)

The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made within a scope not changing the gist of the present invention.

In the above-described embodiment, in addition to the bush holding portion 29b, a restricting portion that restricts movement of the shielding material fixing portion 8c to the outside of the motor case 5 may be formed in the cover 29. In the above embodiment, the movement of the shield fixing portion 8c to the outside of the motor case 5 may be restricted by the bush 43. In this case, the width of the notch 29e in the left-right direction is wider than the outer diameter of the shield material fixing portion 8 c. In this case, the bush 43 serves as a restricting portion for restricting the movement of the shield fixing portion 8c to the outside of the motor case 5, and the bush 43 serving as the restricting portion is attached to the motor case 5. Specifically, the bush 43 as the restricting portion is attached to the cover 29.

In the above-described embodiment, the shield material 37 exposed to the outside with the insulating film 38 removed is folded back once toward the center wire covering portion 8b side in the shield material fixing portion 8c, but the shield material 37 exposed to the outside with the insulating film 38 removed may be folded back multiple times in the shield material fixing portion 8 c. In this case, the tip of the shielding material 37 folded back on the outer peripheral surface of the insulating film 38 may be directed toward the center-wire exposed portion 8 a. In the shield fixing portion 8c, the shield 37 folded back to the outer peripheral surface of the insulating film 38 may not be twisted in the circumferential direction of the core wire coating portion 8 b.

In the above embodiment, the covering member 40 may not cover the central-wire covering portion 8 b. In this case, for example, the inner diameter of the insertion hole 43a of the bush 43 is smaller than that of the bush in the above-described embodiment, and the core wire coating portion 8b not coated with the coating member 40 is press-fitted into the insertion hole 43 a. The covering member 40 may not cover the core wire exposed portion 8 a. In the above-described embodiment, the shield wire 8 may not include the covering member 40.

In the above-described embodiment, the shield material 37 folded back on the outer peripheral surface of the insulating film 38 is fixed by the adhesive 39 in the shield material fixing portion 8c, but the shield material 37 folded back on the outer peripheral surface of the insulating film 38 may be fixed by a heat-shrinkable tube which is heat-shrinkable. In this case, the shielding material 37 folded back on the outer peripheral surface of the insulating film 38 is covered with a heat-shrinkable tube which is heat-shrunk. In this case, for example, a part of the central-wire covering portion 8b on the central-wire exposed portion 8a side and a part of the central-wire covering portion 8a on the central-wire covered portion 8b side are also covered with a heat-shrinkable tube which is heat-shrunk. In the shield fixing portion 8c, the shield 37 folded back to the outer peripheral surface of the insulating film 38 may be fixed with a binding tape.

In the above-described embodiment, the detection means 6 may be other than a rotary encoder. In the above-described embodiment, the motor 1 is an inner rotor type motor, but the motor to which the configuration of the present invention is applied may be an outer rotor type motor.

Claims (9)

1. An electric motor, comprising:

a motor main body portion having a rotor and a stator;

a motor case that houses the motor main body portion;

a detection mechanism housed in the motor housing; and

a shielded wire drawn out from the detection mechanism toward an outside of the motor case,

the shielded wire is provided with: a center wire; a shielding material covering the center wire; and an insulating film covering the shielding material,

the shield wire is formed with: a core wire exposing portion where the shielding material and the insulating film are removed to expose the core wire; and a core wire coating portion in which the core wire is coated with the shielding material and the insulating coating,

a shielding material fixing portion is formed at a boundary portion between the central-wire exposed portion and the central-wire covering portion, the shielding material of the shielding material fixing portion being folded back and fixed to an outer peripheral surface of the insulating coating on the central-wire covering portion side,

the center wire exposed portion and the shield material fixing portion are disposed inside the motor case,

a restricting portion that restricts movement of the shielding material fixing portion to the outside of the motor case is formed or attached to the motor case.

2. The motor according to claim 1,

in the shield material fixing portion, the shield material folded back on the outer peripheral surface of the insulating film is twisted in the circumferential direction of the center wire coating portion.

3. The motor according to claim 1 or 2,

in the shield material fixing portion, the shield material folded back on the outer peripheral surface of the insulating film is fixed by an adhesive.

4. The motor according to claim 3,

the shield wire is provided with a covering member covering at least the shield material fixing portion,

the sheathing member is a heat-shrinkable tube that is heat-shrinkable.

5. The motor according to claim 4,

a bush made of rubber for preventing liquid from penetrating into the motor case,

the bushing is mounted on the motor housing,

an insertion hole through which the center wire coating portion is inserted is formed in the bushing,

the covering member further covers a part of the center wire exposed portion side of the center wire covering portion,

a portion of the center wire covering portion covered with the covering member is press-fitted into the insertion hole.

6. The motor according to claim 5,

the covering member also covers a part of the center wire covering portion side of the center wire exposing portion.

7. The motor according to any one of claims 1 to 6,

the motor case includes a restriction portion forming member made of resin, and the restriction portion is formed on the restriction portion forming member.

8. The motor according to claim 7,

a bush made of rubber for preventing liquid from penetrating into the motor case,

an insertion hole through which the center wire coating portion is inserted is formed in the bushing,

a bush holding portion for holding the bush is formed on the restricting portion forming member,

the restricting portion constitutes a part of the bush holding portion.

9. The motor according to any one of claims 1 to 8,

in the shield fixing portion, a leading end of the shield folded back on the outer peripheral surface of the insulating film faces an outside of the motor case.

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