JP6947015B2 - Rotor core mounting structure - Google Patents

Description

The present invention relates to a rotor of a rotary electric machine, and more particularly to a rotor core mounting structure for mounting a rotor core to a rotor shaft.

Motors that convert electrical energy into rotational kinetic energy, generators that convert rotational kinetic energy into electrical energy, and generator motors that have the functions of both a generator and an electric motor are known. These rotary electric machines operate by the electromagnetic interaction between the permanent magnet provided in the rotor and the coil provided in the stator.

The rotor includes a rotor core and a shaft that penetrates the center of the rotor core. Generally, the rotor core is formed by laminating a plurality of steel plates pierced by a shaft. As a structure for attaching the rotor core to the shaft, there is a structure in which the rotor core is sandwiched between a flange portion formed at one end in the axial direction of the shaft and a caulking portion formed at the other end in the axial direction of the shaft. In this structure, the end plate pierced by the shaft is arranged on the end face of the rotor core, and the end plate is pressed against the rotor core by the caulking portion, so that the rotor core is fixed in the axial direction.

Patent Document 1 describes a rotor core mounting structure for mounting a rotor core having a core member formed in a hollow cylindrical shape and an end plate arranged at an end portion of the core member on a central axis, and extends from the central axis. A mounting structure of a rotor core in which a ring member having a large ductility is attached to the central shaft and the rotor core is attached to the central shaft by crimping the ring member to the end plate side of the rotor core with bending is described. ..

Japanese Unexamined Patent Publication No. 2010-279149

In the rotor core mounting structure described in Patent Document 1, the ring-shaped ring member mounted on the shaft is crimped to the end plate side of the rotor core. In order to form a caulking point by deforming the two members, the ring member and the end plate, a large load is required during caulking, so the equipment for caulking to attach the rotor core has to be increased in size. There is a problem that it will be needed.

The present invention has been made in view of the above problems, and is a rotor core mounting structure for mounting a hollow cylindrical rotor core to a rotor shaft, and forming a caulked portion for mounting the rotor core to the rotor shaft with a smaller load. It is an object of the present invention to provide a mounting structure capable of providing a mounting structure.

The rotor core mounting structure according to the present invention has a hollow cylindrical rotor core and an annular end plate arranged on the axial end face of the rotor core, and is a rotor core mounting structure for mounting the rotor core to the rotor shaft. The end plate is provided with a notch on the inner peripheral surface that exposes a contact surface that is a part of the end surface of the rotor core on the end plate side to the outside, and a thin portion provided on the rotor shaft is provided . The rotor core is brought into the rotor by a caulking portion provided by caulking the thin portion toward the notch portion in the radial direction so that both the contact surface and the axial end surface of the end plate are in contact with each other. It is characterized by being attached to a shaft.

In a preferred embodiment, a plurality of notches arranged at equal intervals along the circumferential direction on the inner peripheral surface of the end plate and a plurality of caulking portions provided on the rotor shaft corresponding to the plurality of notches are provided. Have.

According to the present invention, a notch is provided on the inner peripheral surface of the end plate, and caulking is performed only on the thin portion of the rotor shaft without plastically deforming the end plate to shaft the rotor core and the end plate. A caulking portion that is pressed along the direction can be provided. As a result, the rotor shaft can be crimped with a smaller load as compared with the case of using an end plate having no notch on the inner peripheral surface, and a caulking portion that suppresses the axial movement of the rotor core can be provided. As a result, the equipment for caulking can be downsized.

It is sectional drawing which shows the structure of the rotor to which the mounting structure of the rotor core which concerns on an example of Embodiment is applied. It is a side view which looked at the structure of the rotor of FIG. 1 from the right. It is a figure which shows the structure of a part of the mounting structure of the rotor core which concerns on an example of embodiment. It is a figure which shows the structure of a part of the mounting structure of the rotor core which concerns on an example of embodiment. It is a figure which shows a part structure of the mounting structure of the conventional rotor core.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The dimensions, shape, material, etc. described below are examples for explanation, and can be appropriately changed depending on the specifications of the rotary electric machine and the like.

FIG. 1 is a diagram showing a structure of a rotor 10 used in a rotary electric machine mounted on a vehicle, to which the mounting structure of the rotor core 20 according to the present embodiment is applied. FIG. 1 shows a cross section including the rotation center axis of the rotor 10. FIG. 2 is a side view (external view) of the rotor 10 of FIG. 1 as viewed from the right. Each of FIGS. 3 and 4 is a diagram showing a partial configuration of a mounting structure of the rotor core 20 according to the present embodiment. FIG. 3 shows a state before the rotor shaft 40 is caulked, and FIG. 4 shows a state after the caulking process is performed to form the crimped portion 50.

The rotary electric machine in which the rotor 10 is used is a motor generator that functions as an electric motor when the vehicle is power running and as a generator when the vehicle is braking, and is a three-phase synchronous rotary electric machine. The rotary electric machine is composed of a rotor 10 shown in FIG. 1 and an annular stator arranged on the outer peripheral side of the rotor 10 with a predetermined gap around which a winding coil is wound.

As shown in FIG. 1, the rotor 10 according to the present embodiment includes a rotor core 20, end plates 30 and 32 for pressing the end faces of the rotor core 20, and a rotor shaft 40 to which the rotor core 20 and the end plates 30 and 32 are attached. Be prepared.

The rotor core 20 includes a laminated body 22 in which a predetermined number of magnetic thin plates are laminated, and a plurality of magnets 24 embedded and arranged in the laminated body 22. The laminated body 22 in which magnetic thin plates are laminated has a center hole through which the outer shape of the rotor shaft 40 is passed, and a plurality of magnet holes into which a plurality of magnets 24 are inserted. As the magnetic thin plate, an electromagnetic steel sheet having a predetermined thickness (for example, 0.3 mm, 0.5 mm, 1.0 mm, etc.) can be used. The stacking direction is a direction along the rotation center axis of the rotor 10 (hereinafter, also referred to as “axial direction”). In the laminated body 22, the center hole and the magnet hole extend and penetrate in a direction parallel to the axial direction. Lamination of the magnetic thin plates is performed by integrating a predetermined number of magnetic thin plates punched into a predetermined shape by caulking or the like.

A plurality of magnets 24 are arranged on the outer peripheral side of the rotor core 20 in a predetermined arrangement, and are permanent magnets forming each magnetic pole of the rotor 10. The magnet 24 generates torque in cooperation with a rotating magnetic field generated by applying a predetermined energization to a winding coil wound around a stator of a rotary electric machine (not shown), whereby the rotor 10 rotates.

The end plates 30 and 32 are arranged in contact with both end faces in the axial direction of the rotor core 20, and have an annular shape through which the outer diameter of the rotor shaft 40 is passed. By attaching the end plates 30 and 32 to the rotor shaft 40 so as to sandwich the rotor core 20 between the end plates 30 and 32, the end faces of the rotor core 20 and the magnet 24 in the axial direction (rotor member stacking direction) are pressed.

In the present embodiment, as shown in FIG. 2, a plurality of notches 34 are formed on the inner peripheral surface of the end plate 32 so as to be arranged at equal intervals along the circumferential direction. Here, the end plate 32 provided with the notch portion 34 is arranged on the opposite side in the axial direction from the end plate 30 in contact with the receiving portion 48 provided on the mounting portion 44 of the rotor shaft 40 with the rotor core 20 interposed therebetween. There is.

FIG. 3 shows a part of the mounting structure of the rotor core 20 according to the present embodiment, and shows the structure of the notch 34 provided on the inner peripheral surface of the end plate 32 and its surroundings. However, FIG. 3 shows a configuration before the rotor shaft 40 is caulked. FIG. 3A is a partial cross-sectional view taken along the axial direction, and FIG. 3B is a side view of FIG. 3A as viewed from the right. As shown in FIG. 3A, the notch portion 34 has a bottom portion 34a that is radially outside the inner peripheral surface of the end plate 32 and is parallel to the inner peripheral surface. By forming the notch 34 on the inner peripheral surface of the end plate 32, the contact surface 26 which is a part of the end surface of the rotor core 20 on the end plate 32 side is exposed. The cross section of the notch 34 perpendicular to the axial direction has the cross-sectional shape shown in FIG. 3B in any of the axial directions. As shown in FIG. 3B, the notch 34 is composed of a bottom portion 34a and a side wall 34b extending radially inward from both ends in the circumferential direction of the bottom portion 34a, and has a shape in which the inside in the radial direction is open. In the present embodiment, as will be described later, the crimped portion 50 is crimped outward in the radial direction toward the notch 34 by caulking the end portion (thin-walled portion 49) of the mounting portion 44 of the rotor shaft 40 on the end plate 32 side. Is formed.

Returning to FIG. 1, in the rotor shaft 40, a hollow cylindrical input / output portion 42 for inputting / outputting power and a hollow cylindrical mounting portion 44 having a diameter larger than the input / output portion 42 are connected in a disk shape. It is integrally formed via the portion 46. As described above, the rotor shaft 40 including the input / output portion 42 having a small diameter and the mounting portion 44 having a large diameter improves the degree of freedom in designing the mounting portion 44. Thereby, for example, at the end portion of the mounting portion 44 on the end plate 32 side, it becomes easy to perform caulking processing to form a thin-walled portion 49 for providing the caulking portion 50. When the rotor 10 is used in a rotary electric machine, the rotor shaft 40 is rotatably supported at both ends in the axial direction by bearings and rotates in cooperation with a stator (not shown). As the rotor shaft 40, for example, a steel material such as iron or nickel processed into a predetermined shape can be used.

The rotor core 20 and the end plates 30 and 32 are mounted on the radial outer side of the mounting portion 44. Further, the mounting portion 44 has a receiving portion 48 which is a stepped portion provided on one end side of the rotor shaft 40. The receiving portion 48 comes into contact with the end plate 30 arranged on one end side in the axial direction of the rotor core 20. The contact surface of the receiving portion 48 with the end plate 30 is perpendicular to the axial direction, and the area thereof is set so as to sufficiently receive the force of the rotor core 20 and the end plates 30 and 32 pressing in the axial direction. The mounting portion 44 comes into contact with the inner peripheral surface of the end plate 32 at the thin portion 49 on the side opposite to the receiving portion 48 in the axial direction. The thin-walled portion 49, which comes into contact with the inner peripheral surface of the end plate 32 and forms the caulking portion 50 described later, is thicker in the radial direction than the axial central portion which comes into contact with the inner peripheral surface of the rotor core 20 of the mounting portion 44. Is thinly formed. As a result, the thin-walled portion 49 can be easily caulked so as to be deformed radially outward toward the notch portion 34.

The mounting structure of the rotor core 20 according to the present embodiment has a caulking portion 50 provided by caulking the rotor shaft 40 radially outward toward the notch portion 34 provided on the inner peripheral surface of the end plate 32. FIG. 4 shows a part of the mounting structure of the rotor core 20 according to the present embodiment, which is a configuration of a caulking portion 50 for mounting the rotor core 20 on the rotor shaft 40 and its surroundings. FIG. 4A is a partial cross-sectional view taken along the axial direction, and is also a partially enlarged view of the region A surrounded by the broken line in FIG. FIG. 4B is a side view of FIG. 4A as viewed from the right, and is also a partially enlarged view of the region B surrounded by the broken line in FIG.

As shown in FIG. 4, the caulking portion 50 is formed by a notch 34 in the circumferential direction of the end portion (thin-walled portion 49) of the mounting portion 44 including the contact region with the inner peripheral surface of the end plate 32. It is provided by performing a caulking process that deforms the notch 34 outward in the radial direction at a position adjacent to the space. As a result of such caulking, a part of the rotor shaft 40 is plastically deformed in the caulking portion 50 along the shape of the notch portion 34 provided on the inner peripheral surface of the end plate 32. As a result, the caulking portion 50 presses the contact surface 26, which is an exposed portion of the rotor core 20, and the bottom portion 34a of the notch portion 34 provided in the end plate 32. By this pressing force, the rotor core 20 and the end plate 32 are pressed toward the receiving portion 48, and the rotor core 20 is fixed and held at a position on the rotor shaft 40 together with the end plates 30 and 32.

In the present embodiment, as shown in FIG. 2, 12 notches 34 are provided at equal intervals along the circumferential direction on the inner peripheral surface of the end plate 32, and a total of 12 are provided corresponding to the notches 34. The rotor core 20 is pressed by the crimped portion 50 of the point to fix it (suppress the movement in the axial direction). The positions, numbers, shapes, sizes, etc. of the notch portions 34 and the caulking portions 50 provided on the end plate 32 are not limited, and may be appropriately selected according to the strength required for mounting the rotor core 20 on the rotor shaft 40. .. A plurality of notches 34 arranged at equal intervals along the circumferential direction on the inner peripheral surface of the end plate 32, and a plurality of caulking portions 50 provided on the rotor shaft 40 corresponding to the plurality of notches 34. In the mounting structure having the rotor shaft 40 and the end plate 32, the force of pressing the rotor shaft 40 and the end plate 32 is improved by the plurality of caulking portions 50, so that the rotor core 20 and the end plates 30 and 32 mounted on the rotor shaft 40 can move further in the axial direction. It can be suppressed.

The rotor 10 is assembled as follows. First, the end plate 30 is inserted into the outer periphery of the mounting portion 44 of the rotor shaft 40. Next, the rotor core 20 is similarly inserted into the outer circumference of the mounting portion 44, positioned with the end plate 30 sandwiched between the rotor core 20 and the receiving portion 48, and then the end plate 32 is inserted into the outer circumference of the mounting portion 44. .. Here, the insertion directions of the end plates 30 and 32 and the rotor core 20 are the directions from the thin portion 49 on the right side of the mounting portion 44 toward the receiving portion 48 on the left side in FIG. After that, while applying a pressing force using a jig so that a predetermined axial force acts on the rotor core 20, the end of the mounting portion 44 is located at a position adjacent to the space formed by the notch portion 34. The thin portion 49 on the plate 32 side is bent outward in the radial direction to form the crimped portion 50. As a result, the rotor core 20 is attached to the rotor shaft 40 together with the two end plates 30 and 32, and the movement in the axial direction is suppressed.

Next, the operation and effect of the mounting structure of the rotor core 20 according to the present embodiment will be described.

Here, the mounting structure of the conventional rotor core 20 will be described with reference to FIG. FIG. 5 is a view showing a part of the configuration of the mounting structure of the conventional rotor core 20, and is a partial cross-sectional view taken along the axial direction. FIG. 5A shows a state before the end portion (thin wall portion 61) of the rotor shaft 40 on the end plate 60 side is crimped, and FIG. 5B shows the crimped portion after the caulking process is performed. Shows the state after 62 is formed. In the conventional mounting structure shown in FIG. 5, an end plate 60 having no notch on the inner peripheral surface is used. Therefore, in order to deform the rotor shaft 40 and form a crimped portion 62 sufficient to obtain a pressing force for pressing the end plate 60 and the rotor core 20 along the axial direction, as shown in FIG. 5 (b), the rotor It is necessary not only to bend the thin portion 61 of the mounting portion 44 of the shaft 40 radially outward, but also to plastically deform the region on the inner peripheral surface side of the end plate 60. Therefore, in order to plastically deform the two members of the rotor shaft 40 and the end plate 60 by one caulking process, it is necessary to apply a larger load to perform the caulking process, and the caulking equipment is correspondingly increased. There is a problem of increasing the size.

On the other hand, in the present embodiment, as described above, the notch portion 34 is provided on the inner peripheral surface of the end plate 32, and the notch portion 34 of the thin portion 49 on the end plate 32 side of the mounting portion 44 is provided in the radial direction. The facing positions are plastically deformed by caulking to provide the caulking portion 50. As a result, by caulking only the rotor shaft 40 without plastically deforming the end plate 32, a caulking portion 50 that presses the rotor core 20 and the end plate 32 along the axial direction can be provided. Therefore, as compared with the case of using the end plate 60 having no notch 34 on the inner peripheral surface, it is possible to provide the caulking portion 50 that suppresses the axial movement of the rotor core 20 with a smaller load, and the caulking process can be performed. The equipment to be implemented can be miniaturized.

Further, in the present embodiment, since it is not necessary to plastically deform the end plate 32, the end plate 32 made of a material having higher rigidity can be adopted, and the deformation of the end plate 32 can be prevented and / or the weight can be reduced. Can be done.

Further, as shown in FIG. 4, in the present embodiment, the caulking portion 50 formed by the caulking process is plastically deformed along the shape of the notch portion 34 provided in the end plate 32. That is, in the present embodiment, the shape of the caulking portion 50 that presses the rotor core 20 and the end plate 32 can be controlled not by the magnitude of the load at the time of caulking, but by the shape of the notch portion 34. As a result, the meshing allowance between the rotor core 20 or the end plate 32 and the rotor shaft 40 in the crimped portion 50 (that is, the contact surface 26 which is the exposed portion of the rotor core 20 and the bottom portion 34a and the side wall 34b of the notch portion 34) can be easily provided. Can be adjusted. For example, even if it becomes necessary to increase the pressing force by the caulking portion 50 in order to fix and attach the rotor core 20 to the rotor shaft 40, the size, number, and the number of cutout portions 34 provided in the end plate 32. By changing the setting such as the position, the meshing allowance between the rotor core 20 or the end plate 32 and the rotor shaft 40 can be widened, and the caulking portion 50 capable of obtaining the necessary and sufficient pressing force can be easily formed. As a result, the reliability of the mounting structure of the rotor core 20 can be improved.

In the mounting structure of the rotor core 20 according to the present embodiment, the rotor shaft 40 has a hollow cylindrical input / output portion 42 for inputting / outputting power and a hollow cylindrical mounting portion 44 for mounting the rotor core 20 as a connecting portion. It is integrally formed via 46. However, a rotor shaft formed in a hollow cylindrical shape without having a disk-shaped connecting portion 46 may be used.

The thin portion 49 of the mounting portion 44 of the rotor shaft 40 on which the caulking portion 50 is formed by caulking may be a perfect annular shape having no break in the circumferential direction, but a cut (slit) along the axial direction is provided. It may be the one. For example, in the thin-walled portion, a cut along the axial direction may be provided at a position facing the side wall 34b of the notch portion 34 in the radial direction. As a result, the load required for caulking to form the caulking portion 50 by bending the rotor shaft 40 outward in the radial direction can be further reduced.

Further, in the above description, an embodiment in which end plates 30 and 32 are arranged on both end surfaces in the axial direction of the rotor core 20 and notches 34 are provided on the inner peripheral surface of only one end plate 32 is shown. However, the end plate 32 having the notch 34 on the inner peripheral surface is arranged only at one end in the axial direction of the rotor core 20, and the other end surface in the axial direction of the rotor core 20 does not go through the end plate but receives the receiving portion 48. And may be in direct contact with each other in the axial direction. Further, both of the end plates arranged on the axial end surfaces of the rotor core 20 may be provided with notches 34 on the inner peripheral surfaces thereof. That is, two end plates having notches on the inner peripheral surface are arranged on both end surfaces of the rotor core to sandwich the rotor core, and correspond to the notches provided on the end plates at both ends in the axial direction of the rotor shaft. The structure may be such that a caulking portion is provided by caulking at the position, and the rotor core and the two end plates are fixedly mounted on the rotor shaft by the caulking portion.

10 rotor, 20 rotor core, 22 laminate, 24 magnet, 26 contact surface, 30, 32, 60 end plate, 34 notch, 34a bottom, 34b side wall, 40 rotor shaft, 42 input / output part, 44 mounting part, 46 Connecting part, 48 Receiving part, 49,61 Thin-walled part, 50,62 Caulking part.

Claims (1)

A rotor core mounting structure having a hollow cylindrical rotor core and an annular end plate arranged on the axial end face of the rotor core, and mounting the rotor core to the rotor shaft.
The end plate is provided with a notch on the inner peripheral surface to expose a contact surface which is a part of the end surface of the rotor core on the end plate side to the outside.
By caulking the thin portion radially outward toward the notch so that the thin portion provided on the rotor shaft contacts both the contact surface and the axial end surface of the end plate. The rotor core is attached to the rotor shaft by the provided caulking portion.
Rotor core mounting structure.

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