JP2002199632A - Rotor for rotating electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor for a rotating electric machine, of which the manufacturing is easy and which can transmit a large torque. SOLUTION: The rotor has an input/output shaft (2), a rotor core (1) disposing concentrically inside or outside the input/output shaft (2), and a torque transmitting surface (4a) abutting to an end of the rotor core (1) in the axial direction. It has a first torque transmitting part (3a) solidified or integrally formed to the input/output shaft (2), and a torque transmitting surface (4b) abutting to the other end of the rotor core in the axial direction. It is provided with a second torque transmitting part (3b) solidified to the input/output shaft (2). Further since a part or the whole of the torque transmission between the input/output shaft (2) and the rotor core (1) is made by the friction force between both end surfaces of the rotor core (1) and the torque transmitting surfaces in the axial direction, the rotor for the rotating electric machine having a relatively large capacity and a high speed with no loosening, little shaft eccentricity and high reliability can be obtained at low cost and a high yield rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a rotor of a rotating electric machine.

[0002]

2. Description of the Related Art A rotor of a rotating electric machine is formed by fixing a rotor core to an input / output shaft. The fixing method is as follows: 1) The most common method of press-fitting or shrink fitting;
2) Spline or key method 3) JP-A-8
There is one described in -47203.

[0003]

However, each of these conventional fixing methods has its own problems. 1) In the method by press-fitting and shrink fitting, torque transmission between the input / output shaft and the rotor core is performed between the outer peripheral surface of the input / output shaft and the inner peripheral surface of the hole provided in the rotor core where the input / output shaft is inserted. This is done by friction. Therefore, the larger the torque to be transmitted, the larger the fitting allowance of the inner and outer peripheral surfaces, and the larger the torque. However, if the fitting allowance is too large, the rotor core is cracked, and the press-fitting operation becomes difficult. Therefore, the larger the torque to be transmitted, the higher the dimensional accuracy of the fitting portion needs to be, and in some cases, both the inner and outer peripheral surfaces must be ground,
This leads to an increase in processing costs. 2) In the method using the spline and the key, the torque transmission between the input / output shaft and the rotor core is performed by the shear force at the engagement portion. The problem with this method is that the shapes of the shaft and the hole become complicated, which causes play and increases the eccentricity with respect to the center of the shaft. 3) In the device described in Japanese Patent Application Laid-Open No. 8-47203 shown in FIG. 6, torque transmission between the shaft 15 and the rotor core 12 is performed via the rotary support 18. The rotation support 18 includes a support plate 16 and a vibration absorber 17 (elastic member). The support plate 16 is fixed to the shaft 15, and the vibration absorber 17 is fixed to one end face of the rotor core 12. In this structure, the vibration absorber 17 and the rotor core 12 must be fixed using an adhesive, and it is considered that transmission of a large torque is difficult.

[0004] It is an object of the present invention to provide a rotor of a rotating electric machine that solves such a problem.

[0005]

According to a first aspect of the present invention, there is provided an input / output shaft, a rotor core arranged coaxially inside or outside the input / output shaft, and a torque contacting one end surface of the rotor core in the axial direction. A first torque transmission portion having a transmission surface and fixed or integrally formed with the input / output shaft; and a torque transmission surface contacting the other end surface in the axial direction of the rotor core, and fixed to the input / output shaft. A second torque transmitting portion, wherein part or all of the torque transmission between the input / output shaft and the rotor core is performed by a frictional force between both end surfaces in the axial direction of the rotor core and the torque transmitting surface. An input / output shaft to be performed, a rotor core coaxially arranged inside or outside the input / output shaft, and a torque transmission surface that abuts on one end surface of the rotor core in the axial direction, and is fixed to the input / output shaft. The first integrally molded A torque transmitting surface, which has a torque transmitting surface that abuts on the other end surface in the axial direction of the rotor core, and a second torque transmitting portion that is fixed to the input / output shaft. A part or all of the torque transmission therebetween is performed by a frictional force between both axial end surfaces of the rotor core and the torque transmission surface.

In a second aspect based on the first aspect, the rotor core has a laminated structure in which electromagnetic steel sheets are laminated in the axial direction, and part or all of the torque transmission between adjacent laminated steel sheets is performed. It is performed by the frictional force on the lamination surface.

According to a third aspect of the present invention, in the first or second aspect, an axial tensile stress remains within a range between the two torque transmitting portions of the input / output shaft, and a compression stress is generated inside the rotor core. The residual stress causes the frictional force to be generated by the residual stress.

In a fourth aspect based on any one of the first to third aspects, a thermally conductive filler is filled between the input / output shaft and the rotor core.

In a fifth aspect based on any one of the first to fourth aspects, the rotor core is disposed outside the input / output shaft, and a plurality of projections project from an inner peripheral surface of the rotor core. While the plurality of protrusions are in contact with the outer peripheral surface of the input / output shaft, a gap is formed between the inner peripheral surface and the outer peripheral surface.

[0010]

According to the first and second aspects of the present invention, torque transmission between the electromagnetic steel sheets laminated in the axial direction forming the rotor core and the frictional force between the axial end faces of the rotor core and the torque transmission surface. Is performed by the frictional force on the lamination surface of the rotor core, so that the torque is transmitted by the frictional force between the axial end surface of the rotor core and the torque transmitting surface and the frictional force between the adjacent steel plates, and between the rotor core and the input / output shaft. Therefore, there is no need to directly transmit torque, so that it is possible to obtain a relatively large-capacity, high-rotating electric rotating machine that is free from backlash, has little shaft eccentricity, is inexpensive, has high production yield, and has high reliability.

According to the third aspect of the present invention, the tensile force in the axial direction is left inside the input / output shaft, and the compressive stress is left inside the rotor core. Communication can take place.

[0012] In the fourth aspect, since the heat conductive filler is filled between the input / output shaft and the rotor core, heat generated in the rotor core can be efficiently radiated to the input / output shaft.

In the fifth aspect, the rotor core is disposed outside the input / output shaft, a plurality of projections are projected from the inner peripheral surface of the rotor core, and the plurality of projections are brought into contact with the outer peripheral surface of the input / output shaft. On the other hand, since a gap is formed between the inner peripheral surface and the outer peripheral surface, when the rotor core is inserted into the input / output shaft, the tip of the projection comes into contact with the outer peripheral surface of the input / output shaft, causing plastic deformation. As a result, the centering action automatically works, and the amount of eccentricity can be easily reduced without using a special jig.

[0014]

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

FIG. 1 shows a cross section of a rotor of a rotary electric machine to which the present invention is applied. An electric rotor comprises a rotor core 1 constituted by an iron core or permanent magnet forming a magnetic path, and an input / output shaft 2
And first and second torque transmitting portions 3a and 3b provided integrally with the input / output shaft 2.

A cylindrical rotor core 1 is arranged on the outer periphery of the cylindrical input / output shaft 2 with a predetermined gap in the radial direction.
An axial end face 1 of the rotor core 1 is provided on an outer peripheral face of the input / output shaft 2.
The first and second torque transmitting portions 3a and 3b in the form of hollow disks are fixed by welding so as to sandwich a and 1b from both sides. The respective contact surfaces of the torque transmitting portions 3a and 3b that come into contact with the axial end surface of the rotor core 1
a, 4b, and the transmission of torque is performed by the axial end faces 1a, 1b.
A part or the whole is transmitted by the frictional force between the torque transmitting surfaces 4a and 4b.

To fill the torque transmitting portions 3a and 3b with a filler having high thermal conductivity, a circle is formed between the torque transmitting portions 3a and 3b and the rotor core 1 and near the inner peripheral ends of the torque transmitting portions 3a and 3b. An annular groove 5 is provided, and a gap between the groove 5, the rotor core 1, and the input / output shaft 2 is filled with a filler.
The torque transmitting portions 3a and 3b are provided with holes 6 and 7, respectively, which penetrate the groove 5 into which the filler is filled, function as inlets and outlets when the filler is filled, and are closed after the filling.

With such a configuration, for example, the rotor core 1
When the rotor is an internal permanent magnet type rotor having an outer diameter of φ106 and an inner diameter of φ60, the rotor core 1 is connected to the torque transmitting portion 3a,
The input / output shaft 2 and the torque transmitting portions 3a and 3b were welded to each other with a pressure of 41.2 kN from both sides at 3b, for example, by laser welding, and the entire circumference was welded at a penetration depth of 2 mm. Under these conditions, a rotor capable of withstanding a torque input / output of about 160 N / m could be produced.

FIG. 2 schematically shows a manufacturing process of the rotor according to the present embodiment.

In step 1, a disk-shaped electromagnetic steel sheet as an iron core to be the rotor core 1 is formed by lamination in the axial direction by caulking. In step 2, one of the torque transmitting portions 3a is welded to the input / output shaft 2, and in step 3, a laminated steel plate is inserted into the input / output shaft 2. In step 4, a permanent magnet is inserted through the internal hole of the laminated steel plate, and in step 5, the other torque transmitting portion 3b is inserted into the input / output shaft 2.
In step 6, the rotor core 1 is pressurized by the torque transmitting portions 3a and 3b, and the input / output shaft 2 and the torque transmitting portion 3b are welded all around while maintaining the pressurized state. Compressive stress remains in the rotor core 1 in a state completed by this process, and tensile stress remains in the input / output shaft 2 between the torque transmitting portions 3a and 3b.

In the next step 7, the gap between the groove 5, the rotor core 1 and the input / output shaft 2 is filled with a resin having high thermal conductivity as a filler and cured, and then in step 8, the rotation is balanced. The rotor is completed.

By keeping the compressive stress remaining inside the rotor core 1 and the tensile stress remaining inside the input / output shaft 2 in this manner, the frictional force transmitting a part or all of the torque is changed to the adjacent steel plate. And between the axial end surfaces 1a and 1b of the rotor core 1 and the torque transmitting portions 3a and 3b.

In the present embodiment, the laminated steel sheets are integrated by caulking in advance, but may be integrated using other methods such as bonding. Alternatively, in step 3, the steel plates may be directly inserted into the input / output shaft 2 and laminated without the steel plates being integrated beforehand.

In this embodiment, a resin having a high thermal conductivity is filled. However, the present invention is not limited to this. For example, a method such as aluminum die casting may be used.

As described above, in the present invention, the axial end faces 1a and 1b of the rotor core 1 and the torque transmitting faces 4a and
4b and the frictional force between the adjacent steel plates, it is no longer necessary to directly transmit the torque between the rotor core 1 and the input / output shaft 2, so that there is no backlash and the shaft It is possible to obtain a relatively large-capacity, high-rotating rotating electric machine with low eccentricity, low cost, high production yield and high reliability.

Since the rotor core 1 and the input / output shaft 2 do not directly contact each other, the heat transfer from the rotor core 1 to the input / output shaft 2 is reduced. Since the material having a high conductivity is filled and adhered, heat generated in the rotor core 1 can be efficiently released to the input / output shaft 2.

Although the torque transmitting portions 3a and 3b are fixed to the input / output shaft 2 by welding, one of them may be formed integrally with the input / output shaft.

FIG. 3 shows another rotor manufacturing process as a second embodiment. The configuration of the rotor is the same as that of the first embodiment.

In step 1, a steel sheet is formed by caulking to form a laminate, and in steps 2 and 3, permanent magnets are inserted into the laminated steel sheet to form a rotor core 1, and torque transmitting portions 3a and 3b are installed with the rotor core 1 interposed therebetween. You. In step 4, the rotor core 1 and the torque transmitting portions 3a, 3b are inserted into the input / output shaft 2, and in step 5, the end faces 1a, 1b of the rotor core 1 are pressed from both sides by the torque transmitting portions 3a, 3b, and the pressurized state is maintained. The torque transmitting portions 3a and 3b are welded to the input / output shaft 2 all around. Step 6
Then, after filling a high heat conductive resin into the gap between the groove 5, the rotor core 1, and the input / output shaft 2 and curing the resin, in step 7, the rotation is balanced to complete the rotor. With such steps, the number of manufacturing steps can be reduced while maintaining the same operation as that of the first embodiment.

Next, as a third embodiment, the detailed shape of the inner peripheral portion of the hollow disk-shaped steel plate 1a constituting the rotor core 1 is shown in FIG.

The inner peripheral portion of the steel plate is provided with three projections 8 protruding toward the center thereof. The height of the projection 8 is d, the inner diameter of the steel plate 1a is Rr, and the outer diameter of the input / output shaft 2 is Ra (Rr> Ra). The dimensional relationship between the height d of the projection 8 and the inner diameter Rr of the steel plate 1a and the outer diameter Ra of the input / output shaft 2 is represented by Rr-d <Ra. Therefore, the input / output shaft 2 comes into contact only with the protruding portion 8, and in other regions, a gap of Rr-Ra is formed in the radial direction.

By providing such projections 8, when the rotor core 1 is inserted into the input / output shaft 2, the tip of the projection 8 comes into contact with the outer peripheral surface of the input / output shaft 2 and causes plastic deformation, thereby automatically The eccentricity works, and the amount of eccentricity can be easily reduced without using a special jig. In particular, when the steel plates 1a are stacked and integrated, if the projections 8 are distributed on the inner circumference while being shifted by a constant pitch angle, more favorable when inserting the rotor core 1 into the input / output shaft 2. A centering effect is obtained, and a rotor with extremely small eccentricity can be obtained.

FIG. 5 shows a cross section of a rotor having a configuration in which a rotor core is provided inside and an input / output shaft is provided outside.

The shape of the rotor will be described. The rotor is a cylindrical input / output shaft 2 having a bottom, an annular rotor core 1 inserted therein with a predetermined gap from an inner peripheral surface thereof, And an annular second torque transmitting portion 3d fixed to the input / output shaft 2 by welding while applying a predetermined pressure in the axial direction of the input / output shaft 2. The first torque transmitting unit 3
c is formed integrally with the bottom of the input / output shaft 2. Therefore, the rotor core 1 includes the first and second torque transmitting portions 3c,
The torque transmission surfaces 4c and 4d, which are end surfaces thereof, are sandwiched by 3d at a predetermined pressure in the axial direction. The rotor core 1 is formed by laminating electromagnetic steel sheets as in the first embodiment, and the bottom 2c of the input / output shaft 2 not in contact with the end face of the rotor core 1 is formed to be concave. Although the filler described in the first embodiment is not described in the fourth embodiment,
It goes without saying that the settings are made in the same manner as in the embodiment.

With this configuration, the rotor core 1 is connected to the input / output shaft 2 while maintaining the functions and effects of the first embodiment.
It can be set as the structure arranged inside.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an electric rotor according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a manufacturing process of the electric rotor.

FIG. 3 is a schematic view showing another manufacturing process of the electric rotor of the second embodiment.

FIG. 4 is a detailed view of an inner peripheral portion of a steel plate constituting a rotor core of a third embodiment.

FIG. 5 is a sectional view showing an electric rotor of a fourth embodiment.

FIG. 6 is a diagram illustrating a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor core 2 Input / output shaft 3a-3d Torque transmitting part 4a-4d Torque transmitting surface 5 Filler inlet hole 6 Filler outlet hole 7 Cylindrical groove

Continued on the front page F term (reference) 5H002 AA08 AB05 AB07 AB08 AC02 AC06 AE08 5H622 CA02 CA07 CA13 CB05 PP11 PP16 PP19

Claims (5)

[Claims] An input / output shaft, a rotor core disposed coaxially inside or outside the input / output shaft, and a torque transmitting surface abutting on one axial end surface of the rotor core. A first torque transmitting portion fixed to or integrally formed with the rotor core; and a second torque transmitting portion fixed to the input / output shaft, the second torque transmitting portion having a torque transmitting surface abutting on the other axial end surface of the rotor core. A part or all of torque transmission between the input / output shaft and the rotor core is performed by a frictional force between both axial end surfaces of the rotor core and the torque transmission surface. Rotor. 2. The rotor core has a laminated structure in which electromagnetic steel sheets are laminated in the axial direction, and a part or all of torque transmission between adjacent laminated steel sheets is performed by frictional force on a laminated surface. The rotor of the rotating electric machine according to claim 1, wherein 3. An axial tensile stress remains in a range between the two torque transmitting portions of the input / output shaft, and a compressive stress remains in the rotor core. The rotor of a rotating electric machine according to claim 1, wherein the rotor generates a force. 4. The rotor of a rotating electric machine according to claim 1, wherein a space between the input / output shaft and the rotor core is filled with a thermally conductive filler. . 5. The rotor core is disposed outside the input / output shaft, a plurality of projections are projected from an inner peripheral surface of the rotor core, and the plurality of projections are brought into contact with an outer peripheral surface of the input / output shaft. 5. The rotor for a rotating electric machine according to claim 1, wherein a gap is formed between the inner peripheral surface and the outer peripheral surface. 6.