JP2011239612A - Rotor for rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor for a rotary electric machine capable of reducing manufacturing cost.SOLUTION: A rotor 1 comprises a shaft 10 and a core 20 fitted and fixed to an outer peripheral surface of the shaft 10. The outer peripheral surface of a fitting part 11 on the shaft 10 inserted into the core 20 has a knurl finish composed of first convex lines 12 and first concave grooves 13 along the shaft direction and alternatively along circumferential direction. A circumferential wall surface of a fitting hole 21 in the core 20 into which the shaft 10 is inserted, has second convex line 23 and second concave grooves 24 as many as the first convex lines 12 at an engaging part 22 which engage with the first convex lines 12 and limit relative rotation of the shaft 10 and the core 20 along the circumferential direction.

Description

  The present invention relates to a rotor of a rotating electrical machine mounted on a vehicle, for example.

  For example, as a rotor of a rotating electrical machine mounted on a vehicle, a rotor including a core having a fitting hole and a shaft having a fitting portion fitted into the fitting hole of the core is disclosed in Patent Document 1. Has been. In such a rotor, as one method for fastening the core and the shaft, a key groove extending in the axial direction is provided on the outer peripheral surface of the fitting portion of the shaft and the axial direction is provided on the peripheral wall surface of the core fitting hole. It has been conventionally known that a key extending in the direction is provided and both members are fastened by spline fitting.

Japanese Patent No. 3423485

  However, as described above, when the shaft and the core are fastened by spline fitting, the processing of the key groove provided on the shaft is required to be highly accurate and has a high processing cost because the processing range is wide. .

  This invention is made | formed in view of the said situation, and makes it the problem which should be solved to provide the rotor of the rotary electric machine which enabled it to reduce manufacturing cost.

  The invention according to claim 1, which has been made to solve the above problem, is a rotor of a rotating electrical machine that includes a shaft and a core that is fitted and fixed to the outer peripheral surface of the shaft, and is fitted into the core. In addition, the outer peripheral surface of the fitting portion of the shaft is provided with a first ridge formed in the axial direction formed by knurling, and the peripheral wall surface of the fitting hole of the core into which the shaft is fitted It is characterized in that the same number of engaging portions as the first ridges are provided to engage with the first ridges and restrict relative rotation of the shaft and the core in the circumferential direction.

  According to the first aspect of the present invention, the first ridge formed by knurling is provided on the outer peripheral surface of the fitting portion of the shaft. Since the knurling process can employ an easy processing method such as rack rolling, for example, the manufacturing cost can be reduced. In the case of the present invention, the number of engaging portions provided on the peripheral wall surface of the fitting hole of the core is the same as the number of the first protrusions provided on the shaft. Since the engagement between the first ridge of the shaft and the engaging portion of the core can be easily performed, the fitting operation can be easily performed.

  According to a second aspect of the present invention, a first concave groove extending in the axial direction is formed between the adjacent first ridges on the outer peripheral surface of the fitting portion, and the first concave groove and the first The ridges are provided alternately in the circumferential direction.

  According to the second aspect of the present invention, when the shaft and the core are fitted by press fitting, the convex portion of the engaging portion of the core can pass through the first concave groove of the shaft, so that the fitting work is easy. Can be performed. In addition, even when the first ridge of the shaft is deformed when press-fitted, the deformed portion can escape to the first groove, thus preventing the deformed portion from being scraped and generating chips. be able to.

  The invention according to claim 3 is characterized in that the cross-sectional shape of the engaging portion in the direction perpendicular to the axis is an uneven shape coinciding with the cross-sectional shape in the direction perpendicular to the axis of the fitting portion of the shaft. According to the invention described in claim 3, when the shaft and the core are fitted by making the cross-sectional shape in the direction perpendicular to the axis of the fitting portion of the shaft and the engaging portion of the core coincide with each other, Engagement and alignment between the first ridge of the shaft and the engaging portion of the core can be performed very easily.

  In addition, since the core of a rotor is normally formed by laminating magnetic steel sheets having high hardness, it becomes a member having higher hardness than the shaft. Therefore, when driving the shaft into the fitting hole of the core, there is a possibility that sufficient driving accuracy cannot be ensured or chips are generated. In that respect, in the case of the present invention, a relief space for the convex portion of the core engaging portion is formed between the adjacent first convex strips of the shaft, and the adjacent convex portion of the core engaging portion is formed. Since the clearance space of the 1st protruding item | line of a shaft is formed in the meantime, the favorable driving precision of a shaft can be ensured and generation | occurrence | production of swarf can also be suppressed.

  The invention according to claim 4 is characterized in that the cross-sectional shape in the direction perpendicular to the axis of the engaging portion is an irregular concavo-convex shape that does not coincide with the cross-sectional shape in the direction perpendicular to the axis of the fitting portion of the shaft. . According to the fourth aspect of the present invention, since the cross-sectional shape of the engaging portion provided in the core in the direction perpendicular to the axis can be a simple rectangular shape, for example, the engaging portion can be easily formed. Can do.

  The invention according to claim 5 is characterized in that the engaging portion is constituted by a plurality of slits extending in the axial direction. According to the fifth aspect of the present invention, by forming the slit in the core, the engaging portion that engages with the first protrusion provided on the shaft can be easily formed in the core.

FIG. 3 is a cross-sectional view along the axial direction of the rotor of the rotating electrical machine according to the first embodiment. FIG. 3 is a cross-sectional view in the direction perpendicular to the axis of the rotor of the rotating electrical machine according to the first embodiment. It is explanatory drawing which shows the assembly | attachment state of the rotor of the rotary electric machine which concerns on Embodiment 1, Comprising: (a) shows the state just before the assembly | attachment of a shaft and a core, (b) shows the state of completion of a fitting of a shaft and a core. Show. 6 is a cross-sectional view of a main part in a direction perpendicular to the axis of a core according to Embodiment 2. FIG. It is principal part sectional drawing of the axis orthogonal direction of the core which concerns on Embodiment 3. FIG.

  Hereinafter, an embodiment in which a stator of a rotating electrical machine according to the present invention is embodied will be specifically described with reference to the drawings.

Embodiment 1
FIG. 1 is a cross-sectional view taken along the axial direction of the rotor of the rotating electrical machine according to the first embodiment. FIG. 2 is a sectional view of the rotor in the direction perpendicular to the axis. A rotor 1 of a rotating electrical machine according to the present embodiment is used, for example, in a rotating electrical machine that also serves as an electric motor and a generator of a vehicle. In the housing of the rotating electrical machine, an inner peripheral side of a stator (not shown). It is accommodated in a rotatable manner. As shown in FIG. 1, the rotor 1 includes a shaft 10, a core 20 fitted and fixed to the outer peripheral surface of the shaft 10, first and second stoppers 15 disposed on both sides of the core 20 in the axial direction, 16.

  The shaft 10 is made of a ferrous metal and has a predetermined size, and has a fitting portion 11 to which the core 20 is fitted and fixed at the center in the axial direction. A plurality of first ridges 12 extending in the axial direction are provided on the outer peripheral surface of the fitting portion 11 by knurling the shaft material by rack rolling in advance. The first ridge 12 has a trapezoidal cross-sectional shape in the direction perpendicular to the axis. In this case, a first groove 13 extending in the axial direction and having a V-shaped cross section is formed between adjacent first protrusions 12, and the first groove 13 and the first protrusion 12 are circumferential. Are provided alternately.

  The core 20 is formed in a cylindrical shape by laminating a plurality of circular electromagnetic steel plates having a through hole in the center. A plurality of magnetic poles having different polarities alternately in the circumferential direction are formed on the core 20 by permanent magnets. The core 20 has a fitting hole 21 that penetrates in the axial direction and fits with the fitting portion 11 of the shaft 10. On the peripheral wall surface of the fitting hole 21, there is provided an engagement portion 22 that engages with the first ridge 12 of the shaft 10 to restrict relative rotation of the shaft 10 and the core 20 in the circumferential direction.

  The cross-sectional shape in the direction perpendicular to the axis of the engaging portion 22 is an uneven shape that matches the cross-sectional shape in the direction perpendicular to the axis of the fitting portion 11 of the shaft 10. That is, the engaging portion 22 includes a second convex strip 23 having an inverted V-shaped cross-sectional shape that matches the first concave groove 13 of the shaft 10, and an inverted trapezoidal cross-section that matches the first convex strip 12 of the shaft 10. The second concave grooves 24 having a shape are alternately provided in the circumferential direction. Therefore, the engaging portions 22 of the core 20 are provided with the same number of second ridges 23 and second grooves 24 as the first ridges 12 and the first grooves 13 of the shaft 10.

  The core 20 and the shaft 10 are assembled as shown in FIG. That is, the shaft 10 is fitted and inserted into the fitting hole 21 of the core 20 from the tip in the axial direction (left side in FIG. 3), and one end side of the fitting portion 11 on which the knurling of the shaft 10 is performed reaches the fitting hole 21. At the time, the first ridge 12 and the first groove 13 of the fitting portion 11 and the engagement portion 22 (the second ridge 23 and the second groove 24) of the fitting hole 21 are aligned, and thereafter Then, the shaft 10 is driven and press-fitted until one axial end surface (the right side in FIG. 3) of the core 20 abuts on the first stopper 15 provided on the outer peripheral surface of the shaft 10. Thereby, both members are assembled in a state where the fitting portion 11 of the shaft 10 is positioned in the fitting hole 21 of the core 20. Thereafter, the ring-shaped second stopper 16 (see FIG. 1) is press-fitted from the axial tip end side of the shaft 10 until it comes into contact with the other axial end surface of the core 20 (left side in FIG. 3) to complete the assembly. Let Thereby, the rotor 1 shown in FIG. 1 is obtained.

  As described above, according to the rotor 1 of the rotating electrical machine of the present embodiment, the first ridge 12 and the first groove 13 provided in the fitting portion 11 of the shaft 10 are obtained by knurling by rack rolling. Is formed. Therefore, since the shaft 10 can be produced by an easy processing method, the manufacturing cost can be reduced.

  Further, in the present embodiment, the same number of second ridges 23 of the engaging portion 22 provided on the peripheral wall surface of the fitting hole 21 of the core 20 is provided as the first ridges 12 provided on the shaft 10. Therefore, when the shaft 10 and the core 20 are fitted, the engagement between the first ridge 12 of the shaft 10 and the second ridge 23 of the engaging portion 22 of the core 20 can be easily performed. Therefore, the fitting operation can be easily performed.

  In particular, on the outer peripheral surface of the fitting portion 11 of the shaft 10, a first groove 13 extending in the axial direction is formed between adjacent first protrusions 12, and the first groove 13 and the first protrusion 12 are formed. Since they are provided alternately in the circumferential direction, it is possible to further easily engage and align the first ridges 12 of the shaft 10 and the second ridges 23 of the engaging portions 22 of the core 20. . In addition, even when the first ridge 12 of the shaft 10 is deformed when press-fitted, the deformed portion can escape to the first concave groove 13, so that the deformed portion is scraped off and chips are generated. Can be prevented.

  Furthermore, in the present embodiment, the cross-sectional shape in the direction perpendicular to the axis of the engaging portion 22 of the core 20 is an uneven shape that matches the cross-sectional shape in the direction perpendicular to the axis of the fitting portion 11 of the shaft 10. When the core 20 is fitted, the engagement and positioning between the first protrusion 12 of the shaft 10 and the engaging portion 22 of the core 20 can be performed very easily. Further, a clearance space for the second ridges 23 of the engaging portion 22 of the core 20 is formed between the adjacent first ridges 12 of the shaft 10, and a second adjacent portion of the engaging portion 22 of the core 20. Since the clearance space of the 1st protruding item | line 12 of the shaft 10 is formed between the protruding item | line 23, the favorable driving | operation driving | operation precision of the shaft 10 can be ensured and generation | occurrence | production of swarf can also be suppressed.

[Embodiment 2]
FIG. 4 is a cross-sectional view of a main part of the core 20A according to the second embodiment in the direction perpendicular to the axis. In the present embodiment, only the cross-sectional shape in the direction perpendicular to the axis of the engaging portion 22 (the second ridge 23 and the second groove 24) provided in the core 20 in the first embodiment is changed. In the present embodiment, as shown in FIG. 4, the cross-sectional shape of the second ridge 23A is rectangular, and the cross-sectional shape of the second concave groove 24A is such that the opening width of the opening is narrower than the bottom width of the groove bottom. Inverted trapezoid. That is, in the present embodiment, the cross-sectional shape in the direction perpendicular to the axis of the engaging portion 22A of the core 20A is an irregular uneven shape that does not match the cross-sectional shape in the direction perpendicular to the axis of the fitting portion 11 of the shaft 10.

  According to the rotor of the present embodiment configured as described above, the cross-sectional shapes of the second ridges 23A and the second concave grooves 24A provided in the core 20A are simple shapes, so that the engaging portion 22A can be formed easily.

[Embodiment 3]
FIG. 5 is a cross-sectional view of a main part in a direction perpendicular to the axis of the core 20B according to the third embodiment. In the present embodiment, the engagement portion 22 (the second ridge 23 and the second groove 24) provided in the core 20 in the first embodiment is configured by a plurality of slits 25 extending in the axial direction. It is changed to the joint part 22B. That is, the slit 25 in this embodiment is formed by making a cut extending in the axial direction on the surface of the fitting hole 21B of the core 20B, and a space 25a having a small circular cross section is formed at the bottom. ing. When the core 20B and the shaft 10 are fitted by press-fitting, the slit 25 is formed by a part of the first ridge 12 (see FIG. 2) provided on the shaft 10 entering the slit 25. One ridge 12 is engaged.

  According to the rotor of the present embodiment configured as described above, by forming the slit 25 in the core 20B, the engaging portion 22B that engages with the first ridge 12 provided on the shaft 10 can be 20B can be easily formed.

  DESCRIPTION OF SYMBOLS 1 ... Rotor, 10 ... Shaft, 11 ... Fitting part, 12 ... 1st protrusion, 13 ... 1st ditch | groove, 15 ... 1st stopper, 16 ... 2nd stopper, 20, 20A, 20B ... Core, 21 ... fitting hole, 22, 22A, 22B ... engaging part, 23, 23A ... second convex strip, 24, 24A ... second concave groove, 25 ... slit.

Claims (5)

In a rotor of a rotating electrical machine comprising a shaft and a core fitted and fixed to the outer peripheral surface of the shaft,
On the outer peripheral surface of the fitting portion of the shaft fitted into the core, a first ridge extending in the axial direction formed by knurling is provided,
On the peripheral wall surface of the fitting hole of the core into which the shaft is fitted, there is an engaging portion that engages with the first protrusion and restricts relative rotation of the shaft and the core in the circumferential direction. A rotor of a rotating electrical machine, wherein the same number of protrusions is provided.   A first groove extending in the axial direction is formed between the adjacent first protrusions on the outer peripheral surface of the fitting portion, and the first groove and the first protrusion are alternately provided in the circumferential direction. The rotor of the rotating electrical machine according to claim 1, wherein the rotor is provided.   3. The rotating electrical machine according to claim 1, wherein a cross-sectional shape of the engaging portion in a direction perpendicular to the axis is an uneven shape that matches a cross-sectional shape in the direction perpendicular to the axis of the fitting portion of the shaft. Rotor.   3. The rotation according to claim 1, wherein a cross-sectional shape in a direction perpendicular to the axis of the engagement portion is an irregular concavo-convex shape that does not coincide with a cross-sectional shape in the direction perpendicular to the axis of the fitting portion of the shaft. Electric rotor.   The rotor of the rotating electrical machine according to claim 1, wherein the engaging portion is configured by a plurality of slits extending in an axial direction.

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