JP2018014778A - Press fitting structure of rotary member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press fitting structure of a rotary member capable of suppressing occurrence of burrs when press fitting a collar into a shaft.SOLUTION: A press-fitting structure of a rotor includes: a shaft 31; a cylindrical rotor core press-fitted to the shaft 31; and an annular collar 33 press-fitted into a portion of the shaft 31 located closer to a first end portion with respect to the rotor core. A black skin portion 315 exposed on the outer peripheral surface is formed at the first end portion of the shaft 31. Of the collar 33, on the inner peripheral surface of a press-fit hole 331 into which the shaft 31 is press-fitted, a relief portion 333 for avoiding contact with the black skin portion 315 at the time of press-fitting the collar 33 is formed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a press-fitting structure for a rotating member.

  Conventionally, a motor used in a vehicle drive motor unit or the like includes a rotor. The rotor includes a shaft, a cylindrical rotor core that is press-fitted into the shaft, and a collar that is press-fitted into a portion of the shaft that is positioned closer to the first end than the rotor core (for example, Patent Document 1). reference).

JP-A-11-150929

  By the way, before press-fitting the rotor core and the collar, the shaft described above processes the outer peripheral surface in a state where, for example, the first end surface in the axial direction is held at a plurality of locations in the circumferential direction. Thereby, the black skin part on an outer peripheral surface is mainly removed among shafts. On the other hand, a black skin portion remains in a portion of the first end surface of the shaft that is not subjected to the surface treatment (portion held during the surface treatment). The black skin is rougher than other parts. In this case, if the black skin portion remains on the first end surface of the shaft, the inner peripheral surface of the press-fitting hole in the collar may be caught by the black skin portion when the collar is press-fit from the first end side of the shaft. There is. In this case, a portion of the collar that is caught by the black skin portion is scraped off, which may cause burrs and the like.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a press-fitting structure of a rotating member that can suppress generation of burrs when press-fitting a collar into a shaft.

  In order to achieve the above object, the invention described in claim 1 includes a shaft (for example, the shaft 31 in the embodiment), a cylindrical core press-fitted into the shaft (for example, the rotor core 32 in the embodiment), A rotating member (for example, the rotor 3 in the embodiment) including an annular collar (for example, the collar 33 in the embodiment) press-fitted into a portion of the shaft that is positioned closer to the first end with respect to the core. The first end portion of the shaft is formed with an uneven portion (for example, a black skin portion 315 in the embodiment) exposed to the outer peripheral surface, and the shaft is press-fitted in the collar. In the inner peripheral surface of the press-fitting hole (for example, the press-fitting hole 331 in the embodiment), a relief portion (for example, the embodiment) for avoiding contact with the uneven portion when the collar is press-fitted. Definitive relief portion 333) is formed.

  In the invention according to claim 2, the hardness of the collar is set lower than the hardness of the shaft.

  In the invention described in claim 3, the outer peripheral portion of the collar is provided with a mark (for example, the protrusion 335 in the embodiment) indicating the position of the escape groove.

  In the invention described in claim 4, the uneven portion includes a first uneven portion (for example, the discharge hole 313 in the embodiment) formed on the outer peripheral surface of the first end portion of the shaft, and the first of the shaft. A second uneven portion (for example, a black skin portion 315 in the embodiment) formed on the end surface, and the first uneven portion and the second uneven portion are arranged at the same position in the circumferential direction of the shaft. ing.

  According to the first aspect of the present invention, in the process of press-fitting the collar into the shaft, the portion of the inner peripheral surface of the press-fitting hole in which the relief portion is formed is separated from the outer peripheral surface of the shaft. Is avoided. Therefore, at the time of press-fitting, it is possible to suppress the inner peripheral surface of the press-fitting hole of the collar from being caught by the concave and convex portions. Therefore, the generation | occurrence | production of the burr | flash when press-fitting a color | collar to a shaft can be suppressed.

  According to the invention described in claim 2, when the collar is press-fitted into the shaft, it is possible to suppress the generation of excessive stress on the collar. Thereby, it can suppress that a color breaks.

  According to the invention described in claim 3, even when the escape portion is not visible at the time of press-fitting, or even if the escape portion is not visually observed, the alignment of the concavo-convex portion and the relief portion is performed based on the position of the projection portion. Is possible. As a result, the press-fitting work can be performed efficiently.

  According to the invention described in claim 4, since the first uneven portion and the second uneven portion are formed at the same position in the circumferential direction, the relief portion is shared with respect to the first uneven portion and the second uneven portion. it can. As a result, the number of escape portions provided in the collar is suppressed, so that the area of the portion other than the escape portion in the outer peripheral surface of the press-fitting hole can be secured. As a result, the collar can be firmly fixed to the shaft while suppressing the generation of burrs.

1 is a schematic cross-sectional view of a vehicle drive motor unit according to an embodiment of the present invention. It is a fragmentary sectional view which follows the axial direction of the rotor which concerns on embodiment. It is a perspective view of a shaft and a collar concerning an embodiment. It is a perspective view of the shaft and collar of other composition concerning an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, a case where the press-fitting structure of the rotating member of the present invention is employed in a vehicle drive motor unit (hereinafter simply referred to as “motor unit”) will be described. In the following description, the axial direction of the motor shaft is simply referred to as “axial direction”, the direction around the shaft is simply referred to as “circumferential direction”, and the direction orthogonal to the axial direction is simply referred to as “radial direction”.

[Motor unit]
FIG. 1 is a schematic cross-sectional view of a motor unit 100 according to the embodiment.
As shown in FIG. 1, the motor unit 100 includes a motor housing 101, a sensor housing 102 disposed on the first end side in the axial direction with respect to the motor housing 101, and a second axial direction with respect to the motor housing 101. And a mission housing 103 disposed on the end side.

  The motor 1 is housed inside the motor housing 101. A rotation sensor 104 that detects the number of rotations of the motor 1 is accommodated in the sensor housing 102. The transmission housing 103 accommodates a transmission (not shown) that transmits power from the shaft 31 of the motor 1 to wheels and the like.

A partition wall 105 that partitions the motor housing 101 and the sensor housing 102 is formed between the motor housing 101 and the sensor housing 102. A through hole 106 that penetrates the partition wall 105 in the axial direction is formed at a central portion in the radial direction of the partition wall 105. A bearing 107 that rotatably supports the first end of the shaft 31 of the motor 1 is provided in the through hole 106.
A partition wall 108 that partitions the motor housing 101 and the mission housing 103 is formed between the motor housing 101 and the mission housing 103. A through hole 109 that penetrates the partition wall 105 in the axial direction is formed in a central portion of the partition wall 105 in the radial direction. A bearing 110 that rotatably supports the second end portion of the shaft 31 of the motor 1 is provided in the through hole 109.

  In the motor unit 100, breather passages 111 communicating with each other are formed in the wall portions of the housings 101 to 103. A breather pipe 112 communicating with the breather passage 111 is connected to the wall portion of the mission housing 103. Thereby, the high-pressure and high-temperature air in the motor unit 100 passes through the breather passage 111 and is discharged from the breather pipe 112 to the outside of the motor unit 100.

In the motor unit 100, a refrigerant (not shown) for cooling the motor 1, the bearings 107, 110, and the like is accommodated. As the refrigerant, ATF (Automatic Transmission Fluid), which is hydraulic oil used for transmission lubrication, power transmission, and the like, is preferably used.
An oil pump (not shown) is provided in the motor unit 100. The refrigerant pumped up from the oil pump circulates in the motor unit 100 through a circulation channel (not shown) formed in the motor unit 100. In the process in which the refrigerant circulates in the motor unit 100, the refrigerant is supplied to the motor 1, the bearings 107, 110, and the like.

<Motor>
Next, the configuration of the motor 1 will be described.
The motor 1 is, for example, an inner rotor type IPM motor (embedded magnet synchronous motor). The motor 1 includes a cylindrical stator 2, and a columnar rotor (rotating member) 3 that is disposed on the inner side in the radial direction with respect to the stator 2.

  The stator 2 is formed by laminating magnetic plate materials (not shown) in the axial direction. The stator 2 includes a tooth 21 that extends radially inward. A coil 22 is wound around the tooth 21 via an insulator (not shown).

FIG. 2 is a partial cross-sectional view along the axial direction of the rotor 3.
As shown in FIG. 2, the rotor 3 is press-fitted on both sides in the axial direction with respect to the rotor core 32 of the shaft 31 and the rotor core (core) 32 that is press-fitted coaxially with the shaft 31. A pair of end plates (first end plate 34 and second end plate 35) and a collar 33 press-fitted into a portion of the shaft 31 located closer to the first end with respect to the rotor core 32 are provided.

  The shaft 31 is formed in a cylindrical shape extending in the axial direction. The inner side of the shaft 31 constitutes the internal flow path 311 through which the above-described refrigerant flows. The internal flow path 311 constitutes a part of the above-described circulation flow path. The shaft 31 is made of a material having a Rockwell hardness (HRC) of about 40 to 50 (for example, iron or the like).

  The rotor core 32 is formed by laminating magnetic plate materials 321 in the axial direction. The rotor core 32 is formed with an accommodation hole 322 that passes through the rotor core 32 in the axial direction. A plurality of the accommodation holes 322 are formed at intervals in the circumferential direction. A permanent magnet 323 is accommodated in each accommodation hole 322.

The first end plate 34 is formed in a ring shape from a nonmagnetic material such as stainless steel. The first end plate 34 is press-fitted into a portion of the shaft 31 that is located closer to the first end portion in the axial direction with respect to the rotor core 32. The first end plate 34 closes the accommodation hole 322 from the first end side in the axial direction, and restricts the movement of the permanent magnet 323 toward the first end side in the axial direction.
The second end plate 35 is made of the same material as the first end plate 34 and has the same shape and size as the first end plate 34. The second end plate 35 is press-fitted into a portion of the shaft 31 that is located closer to the second end portion in the axial direction with respect to the rotor core 32. The second end plate 35 closes the receiving hole 322 from the second end side in the axial direction and restricts the movement of the permanent magnet 323 toward the second end side in the axial direction. The second end plate 35 is formed between the rotor core 32 and the diameter-expanded portion 316 formed in a portion of the shaft 31 that is located closer to the second end portion in the axial direction than the second end plate 35. Is held in the axial direction. Thereby, the axial movement of the second end plate 35 relative to the shaft 31 is restricted.

The collar 33 is formed in an annular shape having an outer diameter smaller than that of the first end plate 34. The collar 33 is made of a metal material having a Rockwell hardness (HRC) lower than that of the shaft 31 (for example, 20 to 30). In the present embodiment, the collar 33 is preferably made of carbon steel, high-tensile steel plate, or the like.
The collar 33 has a press-fitting hole 331 into which the shaft 31 is press-fitted. The collar 33 is press-fitted into a portion of the shaft 31 located on the first end side in the axial direction with respect to the first end plate 34. That is, the collar 33 sandwiches the first end plate 34 in the axial direction between the collar 33 and the rotor core 32. Thereby, the collar 33 restricts the movement of the first end plate 34 in the axial direction relative to the shaft 31.

FIG. 3 is a perspective view of the shaft 31 and the collar 33.
As shown in FIG. 3, a plurality of discharge holes (first uneven portions) 313 are formed in the first end portion of the shaft 31 (the portion located on the first end side with respect to the collar 33). Each discharge hole 313 extends in the radial direction and communicates with the inside and outside of the internal flow path 311. That is, in the discharge hole 313, the radially outer end portion opens on the outer peripheral surface of the shaft 31, and the radially inner end portion opens on the inner peripheral surface of the shaft 31. Accordingly, the discharge hole 313 of the present embodiment is recessed inward in the radial direction with respect to the outer peripheral surface of the shaft 31.

  The plurality of discharge holes 313 can be used as a refrigerant flow path that guides the refrigerant supplied to the internal flow path 311 of the shaft 31 to the rotor core 32. Specifically, the refrigerant pumped up by the oil pump and supplied to the internal flow path 311 is discharged from each discharge hole 313 by the centrifugal force generated by the rotation of the rotor 3. Then, the refrigerant discharged from each discharge hole 313 is supplied to the rotor core 32, whereby the rotor core 32 is cooled.

  A black skin portion (second uneven portion) 315 is formed on the first end surface of the shaft 31. The black skin portion 315 is recessed from the first end surface of the shaft 31 to the second end side in the axial direction, and extends in the radial direction so as to communicate the inside and outside of the internal flow path 311. Therefore, the black skin portion 315 is open on the outer peripheral surface of the shaft 31. The black skin portion 315 is a portion of the shaft 31 that is not subjected to surface treatment, and the surface roughness is rougher than that of the shaft 31 other than the black skin portion 315. A plurality of black skin portions 315 are formed at intervals in the circumferential direction.

  In the present embodiment, each black skin portion 315 is formed at the same position (same phase) in the circumferential direction as the corresponding discharge hole 313 described above. Moreover, in this embodiment, the length in the circumferential direction of the discharge hole 313 and the black skin part 315 is equivalent. Therefore, the discharge holes 313 and the black skin portions 315 arranged at the same position in the circumferential direction overlap each other when viewed from the axial direction. However, the same number of black skin portions 315 and discharge holes 313 are not necessarily formed. Further, the discharge hole 313 and the black skin portion 315 may be formed at different positions in the circumferential direction. Furthermore, the circumferential lengths of the discharge hole 313 and the black skin portion 315 may be different from each other.

  Each black skin portion 315 can be used as a refrigerant flow path that guides the refrigerant supplied to the internal flow path 311 of the shaft 31 to one bearing 107 (see FIG. 1). Specifically, the refrigerant pumped up by the oil pump and supplied to the internal flow path 311 is discharged from the black skin portion 315 by the centrifugal force generated by the rotation of the rotor 3. Then, the refrigerant discharged from each black skin portion 315 is supplied to the bearing 107, whereby the bearing 107 is cooled.

  Here, the press-fitting hole 331 in the collar 33 described above is formed smaller than the outer diameter of the shaft 31, and has a tightening margin between the shaft 31 and the shaft 31. A relief portion 333 is formed on the inner peripheral surface of the press-fitting hole 331. The escape portion 333 penetrates the collar 33 in the axial direction and is recessed outward in the radial direction with respect to the inner peripheral surface of the press-fitting hole 331. In the present embodiment, the escape portion 333 is formed in a circular arc shape that protrudes outward in the radial direction in a plan view viewed from the axial direction. However, the plan view shape of the escape portion 333 can be changed as appropriate.

  A plurality of escape portions 333 are formed at intervals in the circumferential direction. Specifically, each escape portion 333 is formed at the same position in the circumferential direction as the corresponding discharge hole 313 and black skin portion 315. It is preferable that the length of each escape portion 333 in the circumferential direction is greater than the length of the discharge holes 313 and the black skin portion 315 in the circumferential direction. The depth in the radial direction of the escape portion 333 can be appropriately changed as long as it does not contact the inner peripheral surface of the discharge hole 313 or the inner surface of the black skin portion 315 when the collar 33 is press-fitted. In addition, the planar view shape in the escape part 333 can be changed suitably.

  On the outer peripheral surface of the collar 33, projections 335 that protrude outward in the radial direction are formed at the same positions in the circumferential direction as the respective escape portions 333 described above. Each protrusion 335 functions as a mark indicating the position of the escape portion 333 in the circumferential direction. The protrusion 335 may be provided corresponding to at least one escape portion 333 among the escape portions 333. Further, the protrusion 335 may be arranged at a position different from the escape portion 333 in the circumferential direction as long as the relative position with the escape portion 333 can be recognized. Furthermore, the protrusion 335 may protrude in the axial direction without being limited to the radial direction.

Next, a method for assembling the rotor 3 will be described.
First, the second end plate 35, the rotor core 32 and the first end plate 34 are sequentially press-fitted into the shaft 31 from the first end side in the axial direction of the shaft 31.

  Subsequently, the collar 33 is press-fitted from the first end side of the shaft 31 in the axial direction. Specifically, first, the shaft 31 is set on a jig (not shown) of a press-fitting device. On the other hand, the inner peripheral portion of the collar 33 is held by a holding jig (magnet chuck or the like) of the press-fitting device. At this time, the shaft 31 and the collar 33 are aligned so that the discharge hole 313 and the black skin portion 315 of the shaft 31 and the protrusion 335 (the escape portion 333) of the collar 33 are in the same position in the circumferential direction. .

  Thereafter, the press-fitting device is driven to move the shaft 31 and the collar 33 closer to each other in the axial direction. Thereby, the shaft 31 is press-fitted into the press-fitting hole 331 of the collar 33 from the first end side in the axial direction. Then, the shaft 31 is press-fitted to a position where the collar 33 contacts the first end plate 34 in the axial direction. As a result, the collar 33 is assembled to the shaft 31. In addition, you may provide the shaft 31 with the guide for aligning the circumferential direction of the discharge hole 313 and the black skin part 315, and the projection part 335 (relief part 333).

Here, in the present embodiment, the collar 33 has the escape portion 333 that avoids the discharge hole 313 and the black skin portion 315 at the same position in the circumferential direction as the discharge hole 313 and the black skin portion 315 of the shaft 31. .
According to this configuration, in the process of press-fitting the collar 33 into the shaft 31, the portion of the inner peripheral surface of the press-fitting hole 331 where the escape portion 333 is formed is separated from the outer peripheral surface of the shaft 31. Contact with skin 315 and discharge hole 313 is avoided. Therefore, it is possible to suppress the inner peripheral surface of the press-fitting hole 331 of the collar 33 from being caught by the inner peripheral surface of the discharge hole 313 or the inner surface of the black skin portion 315 during the press-fitting. Therefore, the generation of burrs when the shaft 31 is press-fitted into the collar 33 can be suppressed.
And in this embodiment, it can suppress that the burr | flash which peeled from the color | collar 33 mixes in a refrigerant | coolant by suppressing generating of a burr | flash.
Moreover, in this embodiment, since it is not necessary to perform the surface treatment of the discharge hole 313 and the black skin part 315 which require time, the cost concerning the surface treatment of the shaft 31 can also be suppressed.

In this embodiment, the hardness of the collar 33 is set lower than the hardness of the shaft 31.
According to this configuration, when the collar 33 is press-fitted into the shaft 31, it is possible to suppress excessive stress from being generated in the collar 33. Thereby, it can suppress that the collar 33 breaks.

In this embodiment, the protrusion 33 335 indicating the position of the escape portion 333 is provided on the outer peripheral surface of the collar 33.
According to this configuration, even if the escape portion 333 cannot be seen as a result of holding the inner peripheral portion of the collar 33 during press-fitting, or the escape portion 333 is not seen, the discharge hole 335 is based on the position of the protrusion 335. 313, the black skin part 315, and the escape part 333 can be aligned. As a result, the press-fitting work can be performed efficiently.

  In the present embodiment, since the corresponding discharge holes 313 and black skin portions 315 are formed at the same position in the circumferential direction, they escape from the discharge holes 313 and black skin portions 315 formed at the same position in the circumferential direction. The part 333 can be shared. Thereby, since the number of the escape parts 333 provided in the collar 33 is suppressed, the area of a part other than the escape part 333 in the outer peripheral surface of the press-fitting hole 331 can be secured. As a result, the collar 33 can be firmly fixed to the shaft 31 while suppressing the generation of burrs.

The technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention.
For example, in the above-described embodiment, the configuration in which the discharge hole 313 is formed on the outer peripheral surface of the shaft 31 and the black skin portion 315 is formed on the first end surface of the shaft 31 is described, but the configuration is not limited thereto. It suffices that at least one of the outer peripheral surface of the shaft 31 and the end surface facing the axial direction has an uneven portion. For example, in the shaft 131 shown in FIG. 4, only the black skin portion 315 is formed on the first end surface in the axial direction. Also with respect to such a shaft 131, by providing the collar 133 with the relief portion 333, it is possible to suppress the occurrence of burrs during press-fitting.

  In the above-described embodiment, the case where the protruding portion 335 is provided as a mark indicating the position of the escape portion 333 has been described. However, the present invention is not limited to this configuration. The mark may be provided by coloring or sticking as long as it is visible.

In the above-described embodiment, the case where the escape portions 333 are provided corresponding to all the discharge holes 313 and the black skin portions 315 has been described, but the configuration is not limited thereto. In other words, the escape portion 333 may be provided corresponding to at least one of the uneven portions.
In the above-described embodiment, the configuration in which the collar 33 is press-fitted into the first end portion of the shaft 31 has been described. It doesn't matter.
In the above-described embodiment, the case where the press-fitting structure of the rotating member of the present invention is applied to the rotor 3 of the vehicle drive motor unit 100 has been described. However, the present invention is not limited to this configuration. For example, the press-fitting structure of the rotating member of the present invention is not limited to a motor for a vehicle, and may be a motor or a generator for other purposes.

  In addition, in the range which does not deviate from the meaning of this invention, it is possible to replace suitably the component in the embodiment mentioned above by the known component, and you may combine the modification mentioned above suitably.

3 ... Rotor (rotating member)
31, 131 ... Shaft
32 ... Rotor core (core)
33, 133 ... collar 331 ... press-fitting hole 313 ... discharge hole (uneven portion, first uneven portion)
315 ... Black skin part (concavo-convex part, second uneven part)
333 ... Escape portion 335 ... Projection (mark)

Claims (4)

A shaft,
A cylindrical core press-fitted coaxially to the shaft;
A rotary member press-fitting structure comprising: an annular collar press-fitted into a portion of the shaft positioned closer to the first end with respect to the core;
The first end portion of the shaft is formed with an uneven portion exposed on the outer peripheral surface,
Of the collar, on the inner peripheral surface of the press-fitting hole into which the shaft is press-fitted, an escape portion is formed to avoid contact with the uneven portion when the collar is press-fitted. Press-fit structure.   2. The press-fitting structure for a rotating member according to claim 1, wherein the hardness of the collar is set to be lower than the hardness of the shaft.   3. The press-fitting structure of the rotating member according to claim 1, wherein a mark indicating a position of the escape groove is provided on an outer peripheral portion of the collar. The uneven portion is
A first concavo-convex portion formed on the outer peripheral surface of the first end portion of the shaft;
A second concavo-convex portion formed on the first end surface of the shaft,
4. The press-fitting of the rotating member according to claim 1, wherein the first uneven portion and the second uneven portion are arranged at the same position in a circumferential direction of the shaft. 5. Construction.

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