JP2009278846A - Rotor shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor shaft capable of facilitating the assembly of an inner peripheral side bearing as well as the assembly of two parts between the inner peripheral portion and outer peripheral portion of a shaft. <P>SOLUTION: A rotor shaft 3 is comprised of an assembly of an inner peripheral portion 4 of a shaft that is disposed to be rotatable around a center axis 12 and an outer peripheral portion 5 of the shaft that is disposed at the outer peripheral side of the inner peripheral portion 4 of the shaft. The inner peripheral portion 4 of the shaft and a cylindrical portion 51 of the outer peripheral portion 5 of the shaft are tightened by fitting an outer peripheral spline 41 formed along the center axial line direction L relative to the outer peripheral surface of the inner peripheral portion 4 of the shaft and an inner peripheral spline 511 formed along the center axial line direction L relative to the inner peripheral surface of the cylindrical portion 51. At the axial end surface of the cylindrical portion 51, an axial restriction part 6 is disposed in opposition to the axial end surface of the inner peripheral portion 4 of the shaft. The rotor shaft 3 is configured in such a manner that the axial restriction part 6 restricts the displacement of the inner peripheral portion 4 of the shaft to the center axial line direction L relative to the outer peripheral portion 5 of the shaft. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotor shaft used for a rotor of a rotating electrical machine.

  For example, in a rotary electric machine such as a motor, generator, motor generator, etc. used in a hybrid vehicle, an electric vehicle, etc., a rotor provided with a magnetic body is rotatably arranged on the inner peripheral side of a stator provided with field windings. ing. And the rotor is comprised using the rotor shaft and the magnetic body attached to this rotor shaft. Such a vehicular rotating electrical machine is disclosed in, for example, an electric motor support mechanism of a vehicular drive device disclosed in Patent Document 1.

Moreover, in patent document 2, in order to make manufacture of a rotor shaft easy, a rotor shaft is divided | segmented into a shaft center part and the shaft outer peripheral part arrange | positioned in the outer periphery, and a shaft is put in the center hole in a shaft outer peripheral part. It is disclosed that the center part is shrink-fitted and fastened together.
By the way, in the above-described rotating electrical machine for a vehicle, the rotor shaft is configured to rotate relative to a rotating shaft connected to the engine and transmit power to the sun gear or the like of the planetary gear mechanism. ing. And the bearings, such as a needle bearing for performing relative rotation with a rotating shaft, are provided in the internal peripheral surface of the rotor shaft.

However, in Patent Document 1, when the bearing is press-fitted into the rotor shaft, it is necessary to press-fit the bearing into the large-sized rotor shaft, and the jig for holding the rotor shaft is enlarged, and the press-fitting is performed. It was necessary to increase the holding force for holding the rotor shaft with a jig.
On the other hand, in Patent Document 2, it is necessary to shrink fit two parts, and the assembly of the rotor shaft is not always easy.

JP 2007-159287 A JP 2007-166862 A

  The present invention has been made in view of such conventional problems, and provides a rotor shaft capable of facilitating the assembly of the inner peripheral bearing and the assembly of the two components of the shaft inner peripheral portion and the shaft outer peripheral portion. It is something to be offered.

The present invention relates to a rotor shaft used for a rotor of a rotating electrical machine,
The rotor shaft is formed by assembling a shaft inner periphery disposed rotatably around a central axis and a shaft outer periphery disposed on the outer periphery of the shaft inner periphery.
On the inner peripheral surface of the shaft inner peripheral part, an inner peripheral side bearing for making the shaft inner peripheral part rotatable relative to the central axis is press-fitted,
The shaft outer peripheral portion is disposed on the outer peripheral side of the cylindrical portion that engages with the inner peripheral portion of the shaft and a magnetic member for attaching a magnetic body for forming a magnetic circuit. The body mounting part is integrally formed,
The inner peripheral portion of the shaft and the cylindrical portion are an outer peripheral spline formed along the central axial direction with respect to the outer peripheral surface of the inner peripheral portion of the shaft, and a central axial direction with respect to the inner peripheral surface of the cylindrical portion It is fastened by fitting with the inner peripheral spline formed along
An axial restriction part facing the axial end face of the shaft inner peripheral part is disposed on the axial end face of the cylindrical part, and the shaft inner peripheral part is arranged on the outer periphery of the shaft by the axial restriction part. The rotor shaft is characterized in that it is configured to restrict displacement in the central axis direction with respect to the portion.

The rotor shaft of the present invention is divided into two parts, an inner peripheral part of the shaft and an outer peripheral part of the shaft, and a structure is devised for fastening these two parts.
Specifically, by dividing the rotor shaft into two parts, a shaft inner peripheral part and a shaft outer peripheral part, the inner peripheral side bearing can be pressed into the shaft inner peripheral part having a small size. As a result, it is possible to prevent an increase in the size of the jig that holds the inner periphery of the shaft, and it is possible to hold the inner periphery of a small shaft when press-fitting the inner periphery side bearing. The power can be reduced. Therefore, the assembly of the inner peripheral bearing to the inner peripheral portion of the shaft can be facilitated.

  In the present invention, the inner periphery of the shaft and the outer periphery of the shaft are fastened by fitting the outer periphery spline formed on the inner periphery of the shaft and the inner periphery spline formed on the cylindrical portion of the outer periphery of the shaft. be able to. When performing this spline fitting, there is a risk that the inner peripheral portion of the shaft and the outer peripheral portion of the shaft may be displaced in the direction of the central axis, whereas in the present invention, the axial direction of the axial end face of the cylindrical portion It is possible to restrict the displacement of the inner peripheral portion of the shaft in the central axis direction with respect to the outer peripheral portion of the shaft by arranging the restricting component.

As described above, in the present invention, the assembly of the shaft inner peripheral portion and the shaft outer peripheral portion can be facilitated by the fastening structure using the spline fitting and the axial restriction member.
Therefore, according to the rotor shaft of the present invention, it is possible to facilitate the assembly of the inner peripheral bearing and the assembly of the two parts, the shaft inner peripheral portion and the shaft outer peripheral portion.

A preferred embodiment of the above-described rotor shaft of the present invention will be described.
In the present invention, the axial restriction component is formed by facing the axial end surface of the cylindrical portion and the axial end surface of the inner peripheral portion of the shaft, and offset from the facing plate portion in the central axial direction. The locking portion is locked by a convex portion formed on the outer peripheral surface in the vicinity of the axial end surface of the cylindrical portion, so that the position in the central axis direction is It is preferable that the shift is restricted (claim 2).
In this case, it is possible to easily regulate the displacement of the axial direction regulating component itself in the central axis direction.

Further, the axial direction regulating component may be formed of a magnetic body having a magnetic force attracted to the axial end surface of the cylindrical portion.
Also in this case, it is possible to easily regulate the displacement of the axial direction regulating component itself in the central axis direction. In addition, the structure which forms an axial direction control component from a magnetic body can be used together with the structure which forms a facing plate part and a latching | locking part in an axial direction control part, or can be employ | adopted independently.

Further, the axial restriction component is constituted by a plurality of division restriction portions formed by being divided in the circumferential direction, and the plurality of division restriction portions are disposed on the entire circumference of the axial end surface of the cylindrical portion. Preferably, the cylindrical portion is formed in an arc shape covering the axial end surfaces of the outer peripheral spline and the inner peripheral spline from the axial end surface of the cylindrical portion.
In this case, it is easy to assemble the axial restricting component to the outer peripheral portion of the shaft, and the inner peripheral portion of the shaft becomes the outer periphery of the shaft by the plurality of division restricting portions arranged on the entire circumference of the axial end surface of the cylindrical portion. It is possible to stably regulate the displacement in the central axis direction with respect to the portion.

The central shaft is connected to the engine, the rotor shaft is rotatably disposed on the inner peripheral side of the stator having field windings, and the outer periphery provided on the outer peripheral surface of the cylindrical portion. It is possible to rotate with respect to the housing in which the stator is fixed via a side bearing, and the axial restriction component is restricted from being displaced in the radial direction by the pressing portion being pressed by the outer peripheral side bearing. It is preferable to configure such that (Claim 5).
In this case, the displacement in the radial direction of the axial direction regulating component itself can be easily regulated.

Further, the cylindrical portion is formed so as to protrude to one side in the axial direction with respect to the inner peripheral portion of the shaft, and the inner peripheral spline in the cylindrical portion is more than the outer peripheral spline in the inner peripheral portion of the shaft. A power transmission component that is formed so as to extend to one side in the axial direction so that it not only fits with the outer peripheral spline in the inner peripheral portion of the shaft but also relatively rotates around the central axis. The outer peripheral surface of the shaft is formed so as to be fitted with an outer peripheral spline formed along the central axial direction, and the shaft inner peripheral portion is restricted from being displaced in one axial direction by the power transmission component. It is preferable that the displacement in the other axial direction is restricted by the axial restriction component (claim 6).
In this case, the power transmission component is used to regulate the displacement of the shaft inner periphery with respect to the shaft outer periphery to one side in the axial direction, and the shaft inner periphery is used to restrict the shaft inner periphery to the shaft outer periphery. The positional deviation to the other side in the axial direction can be restricted.

Embodiments of the rotor shaft according to the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the rotor shaft 3 of this example is used for the rotor 2 of the rotating electrical machine 1, and includes a shaft inner peripheral portion 4 that is rotatably arranged around a central axis 12, and a shaft inner peripheral portion 4. The shaft outer peripheral portion 5 disposed on the outer periphery is assembled. The inner peripheral surface 401 of the shaft inner peripheral portion 4 is press-fitted with an inner peripheral bearing 13 (in this example, a needle bearing) for making the shaft inner peripheral portion 4 rotatable relative to the central axis 12. Yes (see FIG. 6). The shaft outer peripheral portion 5 is disposed on the outer peripheral side of the cylindrical portion 51 and has a cylindrical portion 51 that engages with the inner peripheral portion 4 of the shaft, and a magnetic body 54 for forming a magnetic circuit. The magnetic body attaching portion 53 is integrally formed.

  The shaft inner peripheral portion 4 and the cylindrical portion 51 are formed with respect to the outer peripheral spline 41 formed along the central axis direction L with respect to the outer peripheral surface 402 of the shaft inner peripheral portion 4 and the inner peripheral surface 501 of the cylindrical portion 51. And are fastened by fitting with an inner peripheral spline 511 formed along the central axis direction L (see FIGS. 5 and 6). As shown in FIG. 2, an axial restriction component 6 that faces the axial end surface of the shaft inner peripheral portion 4 is disposed on the axial end surface of the cylindrical portion 51. The rotor shaft 3 is configured to restrict the shaft inner peripheral portion 4 from being displaced in the central axial direction L with respect to the shaft outer peripheral portion 5 by the axial direction restricting component 6.

Hereinafter, the rotor shaft 3 of this example will be described in detail with reference to FIGS.
The rotating electrical machine 1 of this example is a motor, a generator, or a motor generator used for a hybrid vehicle.
As shown in FIG. 1, the central shaft 12 of this example is connected to an engine and is configured to be driven to rotate by being driven by the engine. The rotor 2 is formed by disposing a magnetic body 54 on the rotor shaft 3, and the rotor 2 is rotatably disposed on the inner peripheral side of the stator 7 in which the field winding 72 is disposed on the stator core 71. It is. The stator 7 is fixed to the housing 11, and the rotor shaft 3 is connected to the housing 11 via outer peripheral side bearings 14 </ b> A and B (ball bearings in this example) provided on the outer peripheral surface of the cylindrical portion 51 in the outer peripheral portion 5 of the shaft. Can be rotated with respect to.

In the hybrid vehicle, a power distribution planetary gear mechanism connected on the same axis to the center shaft 12 connected to the engine, a reduction planetary gear mechanism connected to the planetary gear mechanism, and a power distribution planetary gear mechanism. A rotating electrical machine 1 connected to the planetary gear mechanism and operating mainly as a generator, and a rotating electrical machine connected to the reduction planetary gear mechanism and operating mainly as an electric motor are disposed. The rotating electrical machine 1 configured using the rotor shaft 3 of this example operates as the generator.
As shown in FIG. 1, a sun gear 8 (power transmission component) in a planetary gear mechanism for power distribution is connected to one axial side L1 of the rotor shaft 3 of this example.

The cylindrical portion 51 in the shaft outer peripheral portion 5 of this example is formed so as to protrude from the shaft inner peripheral portion 4 to the one side L1 in the axial direction. The inner peripheral spline 511 in the tubular portion 51 is formed to extend to the one axial side L1 with respect to the outer peripheral spline 41 in the shaft inner peripheral portion 4. The inner peripheral spline 511 in the cylindrical portion 51 of the shaft outer peripheral portion 5 not only fits with the outer peripheral spline 41 in the shaft inner peripheral portion 4 but is also centered with respect to the outer peripheral surface of the sun gear 8 in the planetary gear mechanism for power distribution. The outer peripheral spline 81 formed along the axial direction L is also fitted.
The inner peripheral spline 511 and the outer peripheral splines 41 and 81 are formed by a plurality of protrusions and grooves along the central axial direction L.

As shown in FIG. 2, the axial restricting component 6 of this example is disposed on the end surface 515 on the other axial side L <b> 2 of the cylindrical portion 51 of the shaft outer peripheral portion 5, and the other axial side of the cylindrical portion 51. It is disposed on the inner peripheral side of the outer peripheral side bearing 14A provided on the outer peripheral surface 402 of the end portion of L2.
The shaft inner peripheral portion 4 is regulated by the axial restricting component 6 to be displaced in the axial direction other side L2 with respect to the shaft outer peripheral portion 5, and as shown in FIG. 1, the sun gear in the planetary gear mechanism for power distribution is used. 8 (power transmission component) is configured such that the displacement of the shaft outer peripheral portion 5 to the one axial side L1 is restricted.

  As shown in FIG. 2, the axial direction regulating component 6 faces the end surface 515 on the other axial side L <b> 2 of the cylindrical portion 51 in the shaft outer peripheral portion 5 and the end surface 42 on the other axial side L <b> 2 of the shaft inner peripheral portion 4. It has the plate part 62 and the latching | locking part 63 formed offset from the facing plate part 62 to the center axis direction L. As shown in FIG. The locking portion 63 is connected to the facing plate portion 62 by the outer peripheral portion 64.

In the axial direction regulating component 6, the locking portion 63 is locked by the convex portion 513 formed on the outer peripheral surface 402 in the vicinity of the end surface 515 on the other axial side of the cylindrical portion 51, so that the axial direction regulating component 6 moves in the central axial direction L. The positional deviation of is regulated. Moreover, the axial direction control component 6 is restrained from being displaced in the radial direction by the pressing portion 63 (outer peripheral portion 64) being pressed by the outer peripheral bearing 14A. Thereby, when receiving the centrifugal force at the time of rotation, it can hold | maintain firmly so that the axial direction control component 6 may not remove | deviate.
The axial restriction component 6 can be formed of a magnetic material having a magnetic force attracted to the axial end surface of the cylindrical portion 51, and the shaft inner peripheral portion 4 and the shaft outer peripheral portion 5 are formed of the axial restriction component 6. It can be comprised from the metal material which can be made to adsorb | suck. When the axial direction restricting component 6 is made of a magnetic material, a foreign material having a fine magnetic force is adsorbed to prevent the foreign material from being mixed into a sliding portion such as the central shaft 12 and the outer bearing 14A. Can do.

Moreover, as shown in FIG. 2, the convex part 513 is formed in the outer peripheral surface 402 of the cylindrical part 51 in the shaft outer peripheral part 5 of this example in the perimeter. The convex portion 513 is formed to project radially outward in the vicinity of the axial end surface 515 of the concave portion 512 that is recessed and formed on the outer periphery of the end portion on the other axial side L2 of the cylindrical portion 51.
As shown in FIGS. 3 and 4, the axial direction restriction component 6 of this example includes a plurality of division restriction portions 61 that are divided in the circumferential direction in order to facilitate assembly to the shaft outer peripheral portion 5. The plurality of division restricting portions 61 are disposed on the entire circumference of the end surface on the other axial side L2 of the cylindrical portion 51, and the outer peripheral spline 41 and the inner circumference from the end surface 515 on the other axial side L2 of the cylindrical portion 51. The spline 511 is formed in an arc shape covering the end surface on the other axial side L2.

As shown in FIGS. 1 and 5, the magnetic body attaching portion 53 in the shaft outer peripheral portion 5 is provided on the outer peripheral side of a disc-shaped portion 52 formed outward from the outer periphery of the cylindrical portion 51 in the radial direction. A magnetic body 54 for forming a magnetic circuit in the rotating electrical machine 1 is attached to the outer peripheral surface of the magnetic body attachment portion 53.
In the rotating electrical machine 1, the magnetic field for rotating the rotor 2 or the rotation of the rotor 2 is generated by the field winding 72 disposed on the stator core 71 and the magnetic body 54 disposed on the rotor shaft 3. A magnetic circuit for performing is formed.

The rotor shaft 3 of this example is divided into two parts, a shaft inner peripheral part 4 and a shaft outer peripheral part 5, and a device is devised in a structure for fastening these two parts.
Specifically, by dividing the rotor shaft 3 into two parts, the shaft inner peripheral portion 4 and the shaft outer peripheral portion 5, as shown in FIG. 6, the press-fitting of the inner peripheral bearing 13 (needle bearing) has a size. This can be done for the small shaft inner periphery 4. As a result, an increase in the size of the jig for holding the shaft inner peripheral portion 4 can be prevented, and when the inner peripheral bearing 13 is press-fitted, the small shaft inner peripheral portion 4 can be held. The holding force can be reduced. Therefore, the assembly of the inner peripheral bearing 13 to the shaft inner peripheral portion 4 can be facilitated.

  In this example, the shaft inner periphery 4 and the shaft outer periphery 5 are fastened by the outer periphery spline 41 formed on the shaft inner periphery 4 and the inner periphery spline formed on the cylindrical portion 51 of the shaft outer periphery 5. This can be done by fitting with 511. When performing this spline fitting, the shaft inner peripheral portion 4 and the shaft outer peripheral portion 5 may be displaced in the central axis direction L, whereas in this example, the axial direction of the cylindrical portion 51 The axial direction restriction component 6 is disposed on the end surface 515 of the other side L2, and the axial direction restriction component 6 causes the shaft inner peripheral portion 4 to move in the axial direction other side L2 in the central axial direction L with respect to the shaft outer peripheral portion 5. It is possible to regulate the position shift. Further, in this example, the sun gear 8 (power transmission component) in the planetary gear mechanism for power distribution causes the shaft inner peripheral portion 4 to be displaced from the shaft outer peripheral portion 5 to the one axial side L1 in the central axial direction L. Can be regulated.

Moreover, in this example, the assembly | attachment of the shaft inner peripheral part 4 and the shaft outer peripheral part 5 can be made easy by the fastening structure using spline fitting and the axial direction control component 6. FIG.
Therefore, according to the rotor shaft 3 of this example, the assembly of the inner peripheral bearing 13 and the assembly of the two parts of the shaft inner peripheral portion 4 and the shaft outer peripheral portion 5 can be facilitated.

Sectional explanatory drawing which shows the rotary electric machine using the rotor shaft in an Example. Sectional explanatory drawing which shows the periphery of the axial direction control components arrange | positioned in the axial direction end surface of the rotor shaft in an Example. An explanatory view showing a state where a plurality of division restricting parts which constitute an axial direction control part are arranged in an axial end face of a rotor shaft in an example as seen from a central axis direction. Explanatory drawing which shows the state which arrange | positions several division | segmentation control parts in the axial direction end surface of a rotor shaft in the Example, seeing from the center axis line direction. Cross-sectional explanatory drawing which shows the shaft outer peripheral part in an Example. Cross-sectional explanatory drawing which shows the state which press-fits the inner peripheral side bearing to the shaft inner peripheral part in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 11 Housing 12 Central axis 13 Inner peripheral side bearing 14 Outer peripheral side bearing 2 Rotor 3 Rotor shaft 4 Shaft inner peripheral part 41 Outer peripheral spline 5 Shaft outer peripheral part 51 Cylindrical part 511 Inner peripheral spline 513 Protruding part 53 Magnetic body attaching part 54 Magnetic body 6 Axial restricting part 61 Division restricting part 62 Face-to-face plate part 63 Locking part 7 Stator L Center axial direction L1 One axial side L2 The other axial side

Claims (6)

In a rotor shaft used for a rotor of a rotating electrical machine,
The rotor shaft is formed by assembling a shaft inner periphery disposed rotatably around a central axis and a shaft outer periphery disposed on the outer periphery of the shaft inner periphery.
On the inner peripheral surface of the shaft inner peripheral part, an inner peripheral side bearing for making the shaft inner peripheral part rotatable relative to the central axis is press-fitted,
The shaft outer peripheral portion is disposed on the outer peripheral side of the cylindrical portion that engages with the inner peripheral portion of the shaft and a magnetic member for attaching a magnetic body for forming a magnetic circuit. The body mounting part is integrally formed,
The inner peripheral portion of the shaft and the cylindrical portion are an outer peripheral spline formed along the central axial direction with respect to the outer peripheral surface of the inner peripheral portion of the shaft, and a central axial direction with respect to the inner peripheral surface of the cylindrical portion It is fastened by fitting with the inner peripheral spline formed along
An axial restriction part facing the axial end face of the shaft inner peripheral part is disposed on the axial end face of the cylindrical part, and the shaft inner peripheral part is arranged on the outer periphery of the shaft by the axial restriction part. A rotor shaft configured to restrict positional displacement in a central axis direction with respect to a portion.   2. The axial direction restricting component according to claim 1, wherein the axial direction regulating component is offset in the central axial direction from the facing plate portion facing the axial end surface of the cylindrical portion and the axial end surface of the inner peripheral portion of the shaft. And the locking portion is locked by a convex portion formed on the outer peripheral surface in the vicinity of the axial end surface of the cylindrical portion, thereby moving the locking portion toward the central axis direction. A rotor shaft characterized in that displacement is regulated.   3. The rotor shaft according to claim 1, wherein the axial direction regulating component is formed of a magnetic body having a magnetic force attracted to an axial end face of the cylindrical portion. In any one of Claims 1-3, the said axial direction control component consists of the some division | segmentation control part divided | segmented and formed in the circumferential direction,
The plurality of division restricting portions are arranged on the entire circumference of the axial end surface of the cylindrical portion, and have an arc shape that covers the axial end surfaces of the outer peripheral spline and the inner peripheral spline from the axial end surface of the cylindrical portion. A rotor shaft that is formed. In any one of Claims 1-4, the said center axis | shaft is connected with the engine,
The rotor shaft is rotatably arranged on the inner peripheral side of the stator having field windings, and the stator is fixed via an outer peripheral bearing provided on the outer peripheral surface of the cylindrical portion. Rotatable relative to the housing
The axial direction restricting component is characterized in that a displacement in a radial direction is restricted by pressing the locking portion by the outer peripheral side bearing. In any one of Claims 1-5, the said cylindrical part protrudes and forms in the axial direction one side with respect to the said shaft inner peripheral part,
The inner peripheral spline in the cylindrical portion is formed to extend to one side in the axial direction with respect to the outer peripheral spline in the shaft inner peripheral portion, thereby fitting with the outer peripheral spline in the shaft inner peripheral portion. The outer peripheral spline formed along the direction of the central axis with respect to the outer peripheral surface of the power transmission component disposed so as to be relatively rotatable around the central axis,
The shaft inner peripheral portion is configured such that positional displacement to one axial side is restricted by the power transmission component, and positional deviation to the other axial side is restricted by the axial direction regulating component. A rotor shaft characterized by being.

Images