JP2023170325A - Driving device and cover body - Google Patents

Abstract

To provide a technology for improving wire routing in a driving device.SOLUTION: A driving device includes a motor body, an anti-load side cover 32 that covers the motor body from an anti-load side, and a plurality of wires 30A to 30C. The anti-load side cover 32 includes a wire routing groove 50 extending in the circumferential direction, and a plurality of wire drawing holes 52 that are arranged at an interval in the circumferential direction and are connected to the wire routing groove 50. Each of the wires 30A to 30C can be drawn from at least one of the wire drawing holes 52 through the wire routing groove 50.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a drive device and a cover body.

Patent Document 1 discloses a drive device including a motor body and a plurality of wires electrically connected to the motor body.

JP2021-97430A

After studying the drive device disclosed in Patent Document 1, the inventor of the present application recognized that there is room for improvement in the wiring arrangement.

One of the objects of the present disclosure is to provide a technique for improving the routing of wiring used in a drive device.

An aspect of the present disclosure is a drive device. This drive device includes a motor body, an anti-load side cover that covers the motor body from the anti-load side, and a plurality of wires, and the anti-load side cover includes wires extending in a circumferential direction. a routing groove; and a plurality of wiring pull-out holes provided at intervals in the circumferential direction and communicating with the wiring routing groove, each of the plurality of wires passing through the wiring routing groove to the plurality of wires. The wiring can be drawn out from at least one of the wiring drawing holes.

An embodiment of the present disclosure is a cover body. This cover body is used for a drive device including a motor body and a plurality of wires, and has an anti-load side cover that covers the motor body from an anti-load side, and the anti-load side cover has a peripheral a wiring routing groove extending in the direction, and a plurality of wiring extraction holes provided at intervals in the circumferential direction and communicating with the wiring routing groove, each of the plurality of wirings passing through the wiring routing groove. The wire can be drawn out from at least one of the plurality of wire draw-out holes.

According to the present disclosure, routing of wiring can be improved.

FIG. 1 is a partially cross-sectional side view schematically showing a drive device according to an embodiment. FIG. 2 is an enlarged view of FIG. 1; FIG. 3 is a view of the anti-load side cover of the embodiment viewed from the anti-load side in the axial direction together with surrounding structures. FIG. 3 is a perspective view schematically showing the opposite-load side cover of the embodiment together with the surrounding structure. FIG. 3 is an exploded perspective view schematically showing the opposite-load side cover of the embodiment together with the surrounding structure. FIG. 4 is a diagram illustrating another way of routing wiring as seen from the same viewpoint as FIG. 3; FIG. 4 is a diagram illustrating still another way of routing the wiring as seen from the same viewpoint as FIG. 3; FIG. 4 is a view of a modified non-load side cover together with the surrounding structure from the same viewpoint as FIG. 3;

Embodiments will be described below. Identical components are given the same reference numerals and redundant explanations will be omitted. In each drawing, constituent elements are omitted, enlarged, or reduced as appropriate for convenience of explanation. The drawings should be viewed according to the direction of the symbols.

Please refer to FIG. The drive device 10 drives a driven machine by outputting rotation. Specific examples of driven machines are not particularly limited, and include, for example, conveyors, wheels, machine tools, robots (industrial robots, service robots, etc.).

The drive device 10 of this embodiment is an actuator. This drive device 10 includes, in addition to a motor device 12 that outputs rotation from a rotor shaft 22, a speed reducer 14 that decelerates the rotation output from the rotor shaft 22 and outputs it to a driven machine from an output section 14a. In addition, the drive device 10 includes a rotating body 16 that rotates when the drive device 10 is in operation. The rotating body 16 of this embodiment is a combination of a rotor shaft 22 and a rotor 26, which will be described later. Hereinafter, the direction along the rotation center line C22 of the rotor shaft 22 will be referred to as the axial direction X, and the circumferential direction and radial direction of a circle centered on the rotation center line C20 will be simply referred to as the circumferential direction and the radial direction. Further, in the axial direction X, the output side (here, the left side in the figure) is called the load side, and the opposite side is called the anti-load side.

See FIG. 2. The motor device 12 includes a motor body 18, a housing 20 that accommodates the motor body 18, and a rotor shaft 22 that rotates integrally with a rotor 26 of the motor body 18. The rotor shaft 22 is rotatably supported by a bearing (not shown) built into the motor device 12 (housing 20).

The motor body 18 includes a stator 24 and a rotor 26 that generate a rotating magnetic field. The motor main body 18 of this embodiment constitutes a three-phase DC motor. The type of motor that constitutes the motor body 18 is not particularly limited, and may be, for example, a DC motor, an AC motor, a coreless motor, a brushed motor, a brushless motor, a permanent magnet motor, an induction motor, a reluctance motor, or the like.

The stator 24 is, for example, a stator with a core configured by incorporating multiple-phase (here, three-phase) coils (not shown) into a stator core 24a. The type of stator 24 is not particularly limited, and may be a coreless stator or the like. The stator 24 is fixed to the housing 20 using an interference fit (shrink fit), an adhesive, or the like.

The rotor 26 of this embodiment is a magnet type rotor in which a permanent magnet (not shown) is incorporated in the rotor core 26a. The type of rotor 26 is not particularly limited, and may be a wire-wound rotor, a squirrel cage rotor, a coreless rotor, or the like. Rotor 26 is secured to rotor shaft 22 using an interference fit, adhesive, or the like.

The housing 20 has a cylindrical shape as a whole. The housing 20 includes a counter-load side opening 20a provided at its counter-load side end.

Please refer to FIGS. 2 to 5. The drive device 10 includes a plurality of wires 30A to 30C, an anti-load side cover 32 that covers the motor main body 18 from the anti-load side, and a lid 34 provided separately from the anti-load side cover 32. The combination of the counter-load side cover 32 and the lid body 34 is also referred to as a cover body 36.

The wires 30A to 30C electrically connect the internal electrical device 38 disposed within the housing 20 and a counterpart electrical device different from the internal electrical device 38. For example, the internal electric device 38 is either the stator 24 or the rotor 26 of the motor body 18, and the other electric device is a motor driver (not shown) that supplies power to the motor body 18. Here, an example will be described in which the internal electric device 38 is the stator 24 and the counterpart electric device is provided outside the drive device 10 and separately from the drive device 10. In addition to this, the counterpart electric device may be incorporated into the drive device 10 as a part of the drive device 10.

A portion 30a of the wirings 30A to 30C is disposed within the anti-load side space 40 between the motor main body 18 and the anti-load side cover 32 within the housing 20. The wirings 30A to 30C are provided so as to pass through the anti-load side opening 20a of the housing 20 and the inside of the anti-load side cover 32. When the wirings 30A to 30C are electrically connected to the stator 24, they are mechanically connected to a part of the stator 24 (a coil not shown here). The drive device 10 of this embodiment includes a total of three wires 30A to 30C that correspond to each coil of each phase (here, three phases, U phase, V phase, and W phase) of the stator 24. In FIG. 3, the center lines of the individual wirings 30A to 30C are indicated by dashed-dotted lines. Further, one end of each of the wirings 30A to 30C leading to the internal electrical equipment 38 is marked with "S", and the other end leading to the other end of the wiring 30A to 30C is marked with "G", and these are omitted. Further, one end side portion and the other end side portion of the same wiring 30A to 30C are indicated using the alphabet added to the end of the wiring 30. For example, "S(A)" and "G(A)" indicate one end side portion and the other end side portion of the same wiring 30A. Each of the three wires 30A to 30C is electrically connected to its corresponding coil, and serves as a current-carrying path to the corresponding coil.

The anti-load side cover 32 covers the motor main body 18 from the anti-load side. The anti-load side cover 32 of this embodiment covers the stator 24 and rotor 26 of the motor body 18 from the anti-load side, and also covers the housing 20 from the anti-load side. The anti-load side cover 32 of this embodiment has a plate shape as a whole.

The anti-load side cover 32 includes a through hole 42 provided at a position overlapping in the axial direction X with the hollow portion 16a that passes through the rotating body 16 (rotor shaft 22). The through hole 42 is provided for inserting an insertion member (not shown) inserted into the hollow portion 16a of the rotating body 16. The insertion member is, for example, other wiring such as a communication line. Note that if the rotating body 16 does not have the hollow portion 16a, the through hole 42 may not be provided in the anti-load side cover 32.

The counter-load side cover 32 is integrated with the housing 20. The counter-load side cover 32 is integrated into the housing 20 by being fixed to the housing 20 using fixing means (not shown) such as bolts, threaded structure, interference fit, or adhesive, for example.

The anti-load side cover 32 has a wiring routing groove 50 that extends in the circumferential direction, a plurality of wiring extraction holes 52 that are provided at intervals in the circumferential direction and communicate with the wiring routing groove 50, and a wire routing groove 50 that extends from the motor body 18 side (load side). A wire lead-in portion 54 is provided for drawing in the wires 30A to 30C and guiding them to the wire routing groove 50. The wire lead-in hole 52 also serves as the wire lead-in portion 54 in this embodiment.

The wiring groove 50 of this embodiment has an end shape having end portions 50a on both sides in the circumferential direction. It can also be said that the wiring routing groove 50 has a shape that does not continue annularly in the circumferential direction but exists only in a part of the circumferential range. The wire routing groove 50 is provided in a range from the end 50a to the nearest wire pull-out hole 52 (wire lead-in portion 54), and includes a dead-end area 50b that becomes a dead-end toward the end 50a in the circumferential direction.

The wiring groove 50 includes an opening 56 that opens on one side in the axial direction. The opening 56 in this embodiment is open on the opposite load side in the axial direction. The wiring groove 50 has a bottomed structure with a bottom 50c on the motor main body 18 side (load side).

The number of wiring extraction holes 52 in this embodiment is three in total, which is the same number as the number of wirings 30A to 30C electrically connected to the motor body 18. The number of wiring extraction holes 52 is not particularly limited as long as it is plural, and may be two, four or more, for example. The wiring pull-out hole 52 of this embodiment has an opening 52a that opens on the outer peripheral surface of the counter-load side cover 32, and the wirings 30A to 30C can be pulled out radially outward from the opening 52a. In order to realize this, the wiring pull-out hole 52 of this embodiment extends in the radial direction from the wiring routing groove 50 toward the opening 52a. Alternatively, the opening 52a may be opened on the axial side surface of the counter-load side cover 32, and the wirings 30A to 30C may be drawn out from the opening 52a toward the counter-load side in the axial direction X.

The wiring lead-in portion 54 is provided as a hole through which the wirings 30A to 30C can pass. The wire lead-in portion 54 communicates with the wire routing groove 50 similarly to the wire lead-out hole 52 . A plurality of wiring lead-in portions 54 of this embodiment are provided at intervals in the circumferential direction, similarly to the wire lead-out holes 52. Each of the plurality of wire lead-in portions 54 also serves as an individual wire lead-out hole 52. The number of wire lead-in portions 54 in this embodiment is three in total, which is the same number as the number of wires 30A to 30C electrically connected to the motor body 18, similar to the wire lead-out holes 52. The wiring lead-in portion 54 includes an opening 54a that opens at a location facing the counter-load side space 40, and the wirings 30A to 30C can be drawn through the opening 54a. The wire lead-in portion 54 of this embodiment extends in the axial direction X from the opening 54a toward the wire routing groove 50.

The lid body 34 closes the opening 56 of the wiring routing groove 50 of the counter-load side cover 32 from the axial direction X. The lid body 34 of this embodiment is a plate material, and closes the opening 56 of the counter-load side cover 32 from the counter-load side. The lid body 34 is fixed to the counter-load side cover 32 using fixing means (not shown) such as bolts, interference fit, or adhesive, for example.

The drive device 10 includes a locking portion 58 that is provided in the wire routing groove 50 and locks the wires 30A to 30C. The locking portion 58 of this embodiment is a convex portion protruding from the inner surface (bottom portion 50c) of the wiring routing groove 50. In addition to this, the locking portion 58 may be provided on the lid body 34. The shape of the locking portion 58 may be any shape that allows the wirings 30A to 30C to be hooked thereon, and its specific example is not particularly limited. The locking portions 58 of this embodiment are provided in each of the individual blind alley areas 50b of the wiring routing groove 50.

Refer to FIGS. 2 and 3. Each of the plurality of wires 30A to 30C is drawn in from the counter-load side space 40 through the wire lead-in portion 54 and guided into the wire routing groove 50. In the illustrated example, individual wires 30A to 30C are drawn in from each of the plurality of wire lead-in portions 54 and guided to the common wire routing groove 50. S(A), S(B), and S(C) in FIG. 3 show a state in which one end side portion of each of the wirings 30A to 30C is drawn through an individual wiring lead-in portion 54. The wires 30A to 30C guided into the wire routing groove 50 are routed in the circumferential direction within the wire routing groove 50 from the wire lead-in portion 54 toward the wire pull-out hole 52. As a result, each of the plurality of wires 30A to 30C is pulled out from at least one of the plurality of wire pull-out holes 52 through the wire routing groove 50.

In this embodiment, a plurality of wires 30A to 30C are pulled out from one of the plurality of wire pull-out holes 52. Here, "combined" means that the plurality of wires 30A to 30C are bundled into one on the route from the wire routing groove 50 to one wire pull-out hole 52, regardless of whether or not they are bundled. “Pull out multiple wires 30A to 30C that are bundled” refers to pulling out multiple wires 30A to 30C that are bundled together from one wire pull-out hole 52, regardless of whether they are bundled or not. Become. Although the embodiment shows an example in which the plurality of wires 30A to 30C are not bundled, they may be bundled using a binding tool such as a binding band.

In this embodiment, at least one of the wires 30A to 30C is routed so as to reciprocate in the wire routing groove 50 in the circumferential direction. In this embodiment, all the wirings 30A to 30C satisfy this condition. By routing the wires 30A to 30C so as to reciprocate within the wire routing groove 50 in this manner, the length of the portion of the wires 30A to 30C drawn out from the wire pullout hole 52 can be adjusted. In routing the wires 30A to 30C in this manner, the wires 30A to 30C are locked to the locking portions 58 in the wire routing groove 50. In the wirings 30A to 30C of this embodiment, the folded portions 30b of the wirings 30A to 30C, which are formed by reciprocating within the wiring routing groove 50, are locked by the locking portions 58. By locking the wires 30A to 30C to the locking portion 58 in this manner, it is possible to suppress positional fluctuations of the wires 30A to 30C during the work of routing the wires 30A to 30C within the wire routing groove 50, resulting in good workability. can be obtained.

Effects related to the above features will be explained.

Each of the plurality of wires 30A to 30C can be drawn out from at least one of the plurality of wire draw-out holes 52 of the anti-load side cover 32. Therefore, by changing the wiring extraction holes 52 from which the wirings 30A to 30C are drawn out, the extraction positions of the wirings 30A to 30C can be easily changed. As a result, by changing only the lead-out positions of the wirings 30A to 30C according to the peripheral structure of the drive device 10 without changing the position of the drive device 10, it is possible to realize a flexible response according to the peripheral structure of the drive device 10. become. As a result, the routing of the wirings 30A to 30C can be improved. For example, as shown in FIG. 6, if there is an obstacle 70 around a particular wiring extraction hole 52 that causes interference with the wirings 30A to 30C, by pulling out the wirings 30A to 30C from other wiring extraction holes 52, Interference with the obstacle 70 can be avoided. In addition to this, when fixing the drive device 10 to an external member, a case is assumed in which the relative position in the circumferential direction with respect to the external member changes. Even in this case, by changing only the lead-out positions of the wirings 30A to 30C, it is possible to avoid large fluctuations in the lead-out positions before and after the relative position of the drive device 10 with respect to the external member changes.

Further, each of the plurality of wires 30A to 30C is accommodated in the wire routing groove 50 by passing through the wire routing groove 50. Therefore, even if the wirings 30A to 30C try to shift in position in the radial direction, the wirings 30A to 30C contact the inner surface of the wiring routing groove 50, so that the positional shift can be regulated. Such positional displacement of the wirings 30A to 30C may occur, for example, when an unintended external force is applied to the drawn-out portions of the wirings 30A to 30C. Furthermore, it is possible to prevent the wirings 30A to 30C from coming into contact with the rotating body 16 due to the positional deviation.

In addition, when routing the plurality of wires 30A to 30C, it is only necessary to route each of the wires 30A to 30C so as to pass through the wire extraction hole 52, the wire routing groove 50, and the like. Therefore, good workability can be obtained when routing the plurality of wires 30A to 30C.

Further, a plurality of wires 30A to 30C combined into one are pulled out from any one of the plurality of wire pull-out holes 52. Therefore, by handling the plurality of wires 30A to 30C pulled out from one wire pull-out hole 52 in a bundled state, it is possible to improve the handling of the wires.

The wiring groove 50 includes an opening 56 that opens on one side in the axial direction. Therefore, the wires 30A to 30C can be easily placed into the wire routing groove 50 from the outside of the counter-load side cover 32 through the opening 56.

The drive device 10 includes a lid 34 that closes the opening 56 of the wiring groove 50. Therefore, the lid 34 can protect the wires 30A to 30C within the wire routing groove 50.

The wiring routing groove 50 has a bottomed structure with a bottom portion 50c on the motor main body side. Therefore, the bottom portion 50c of the wiring groove 50 can restrict the displacement of the wirings 30A to 30C toward the motor body 18 side. Furthermore, contact with the rotating body 16 on the motor main body 18 side with respect to the anti-load side cover 32 due to misalignment of the wirings 30A to 30C can be prevented.

The wire lead-out hole 52 also serves as a wire lead-in portion 54. Therefore, the configuration of the anti-load side cover 32 can be simplified rather than separately providing the wire lead-out hole 52 and the wire lead-in portion 54.

The wiring groove 50 has an end shape having end portions 50a on both sides in the circumferential direction. Therefore, compared to the case where the wiring routing groove 50 is continuous in an annular shape, the lengths of the wirings 30A to 30C passing through the wiring routing groove 50 can be prevented from becoming excessively long. This makes it possible to suppress noise from entering the wirings 30A to 30C. Further, when electrically connecting the wirings 30A to 30C to the motor body 18, it is possible to suppress the adverse effect on motor characteristics caused by an increase in the length of the wirings 30A to 30C.

Next, modifications of each of the constituent elements described so far will be described.

The drive device 10 has been described using an example of an actuator including a reduction gear 14. The drive device 10 is not limited to this, and may be configured, for example, by only the motor device 12, or by the motor device 12 and a power transmission device (for example, a power distributor) other than the reducer 14. good. Furthermore, the drive device 10 does not need to include the lid 34. It can also be said that the cover body 36 does not need to include the lid body 34.

The specific example of the type of reducer 14 is not particularly limited. For example, a flexible mesh type reducer, an eccentric oscillating type reducer, a simple planetary type reducer, an orthogonal axis gear mechanism, a parallel axis gear mechanism, etc. may be used. The type of the flexible mesh type reducer is not particularly limited, and may be, for example, cylindrical, top hat, cup, or the like. The type of eccentric swing type reducer is not particularly limited, and examples include a center crank type in which the crankshaft is placed on the center line of the internal gear, a distribution type in which the crankshaft is placed at a position offset from the center line, etc. But that's fine. Further, the type of speed reducer 14 may be either a gear speed reducer or a traction speed reducer.

A specific example of the rotating body 16 is not particularly limited. The rotating body 16 includes, for example, in addition to the first rotating body including the rotor shaft 22, a second rotating body that is rotatable integrally with the output shaft of the reducer 14 and has a rotating shaft passing through the rotor shaft 22. Good too. Further, the rotating body 16 may include a part (detected part) of a rotary encoder described later.

When the wirings 30A to 30C are electrically connected to the motor body 18, they may be electrically connected to the rotor 26 instead of the stator 24. This assumes, for example, that the rotor 26 is constituted by a wire-wound rotor incorporating coils. In this case, the wirings 30A to 30C may be electrically connected to the rotor 26 by being mechanically connected to a rotational connection connector that is electrically connected to the rotor 26. The rotary connector is, for example, a combination of a slip ring and a brush, a liquid metal rotary connector, or the like. In either case, the wires 30A to 30C may be drawn into the wire lead-in portion 54 of the counter-load side cover 32 from the counter-load side space 40 in the housing 20 where the part 30a of the wires 30A-30C is arranged. .

The anti-load side cover 32 may also serve as a sensor mount for attaching a sensor used in the drive device 10. This sensor becomes part of a rotary encoder, for example. In addition to the sensor, the rotary encoder includes a detected portion that becomes a part of the rotating body 16. The detected portion is attached to the rotor shaft 22, for example. The sensor and the detected part are, for example, a combination of a magnetic sensor and a magnetic scale, a combination of an optical sensor and an optical scale, or the like. The sensor can detect the rotation of the rotating body 16 by detecting a change in a predetermined physical quantity (magnetic field, amount of light, etc.) when the detected part rotates.

In addition to the first internal electrical device that is the motor body 18, the internal electrical device 38 may include at least one second internal electrical device different from the first internal electrical device. The second internal electrical equipment is, for example, a sensor (temperature sensor, pressure sensor, etc.), brake, or the like. It can be said that the wirings 30A to 30C may include, in addition to the first wiring (motor wiring) electrically connected to the motor body 18, a second wiring connected to a second internal electric device. Also in this case, even if each of the first wiring and the second wiring is drawn into the wiring lead-in portion 54 of the anti-load side cover 32 from the anti-load side space 40 in the housing 20 where the part of the wiring 30a is arranged, good.

The wiring groove 50 does not need to have the opening 56 that opens in the axial direction X. In addition to this, the wiring routing groove 50 may be provided with individual openings 56 that open on both sides in the axial direction. It can also be said that the wiring routing groove 50 does not need to have a bottomed structure. The wiring groove 50 may be continuous in an annular manner in the circumferential direction. The wire lead-out hole 52 and the wire lead-in portion 54 may be provided separately.

In the embodiment, an example has been described in which a plurality of wires 30A to 30C are drawn out from one of the plurality of wire draw-out holes 52. In addition, as shown in FIG. 7, one or more wires 30A to 30C may be drawn out from each of the plurality of wire draw-out holes 52.

Refer to FIG. A cylindrical grommet 72 may be attached to the wiring extraction hole 52 to protect the wirings 30A to 30C. In this case, the wirings 30A to 30C will be drawn out through the grommet 72. The grommet 72 is made of, for example, a soft elastic material, metal, hard resin, or the like.

The above embodiments and modifications are illustrative. These abstracted technical ideas should not be interpreted as being limited to the contents of the embodiments and modified forms. The contents of the embodiments and modified forms may be subject to many design changes such as changes, additions, and deletions of constituent elements. In the embodiments described above, the content that allows such design changes is emphasized by adding the notation "embodiment". However, design changes are allowed even if there is no such notation. The hatching added to the cross section of the drawing does not limit the material of the hatched object. The structures mentioned in the embodiments and the modified embodiments naturally include structures that can be considered to be the same when manufacturing errors and the like are taken into account.

In the embodiment, a component made up of a single member may be made up of a plurality of members. Similarly, a component configured with multiple members in an embodiment may be configured with a single member.

DESCRIPTION OF SYMBOLS 10... Drive device, 18... Motor body, 30A-30C... Wiring, 32... Counter-load side cover, 34... Lid body, 36... Cover body, 50... Wiring routing groove, 50a... End part, 50c... Bottom part, 52... Wiring pull-out hole, 54... Wiring lead-in part, 56... Opening part, 58... Locking part.

Claims (9)

A drive device comprising a motor body, an anti-load side cover that covers the motor body from an anti-load side, and a plurality of wires,
The anti-load side cover includes a wiring routing groove extending in the circumferential direction, and a plurality of wiring extraction holes provided at intervals in the circumferential direction and communicating with the wiring routing groove,
Each of the plurality of wires can be drawn out from at least one of the plurality of wire draw-out holes through the inside of the wire routing groove. The drive device according to claim 1, wherein the plurality of wires grouped into one can be drawn out from any one of the plurality of wire draw-out holes. The drive device according to claim 1 or 2, wherein the wiring routing groove has an opening that opens on one side in the axial direction. The drive device according to claim 3, further comprising a lid that is provided separately from the counter-load side cover and closes the opening from the axial direction. The drive device according to claim 1 or 2, wherein the wiring routing groove has a bottomed structure having a bottom on the motor main body side. 3. The drive device according to claim 1, wherein the wire lead-out hole also serves as a wire lead-in portion for drawing the wire from the motor main body side and guiding it to the wire routing groove. 3. The drive device according to claim 1, wherein the wiring routing groove has an end shape having end portions on both sides in the circumferential direction. The drive device according to claim 1 or 2, further comprising a locking portion provided in the wiring groove and locking the wiring. A cover body used in a drive device including a motor body and a plurality of wires, the cover body having an anti-load side cover that covers the motor body from an anti-load side,
The anti-load side cover includes a wiring routing groove extending in the circumferential direction, and a plurality of wiring extraction holes provided at intervals in the circumferential direction and communicating with the wiring routing groove,
Each of the plurality of wires can be drawn out from at least one of the plurality of wire draw-out holes via the wire routing groove.

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