CN112703662A - Rotating electric machine and method for manufacturing same - Google Patents

Abstract

The invention provides a rotating electric machine and a manufacturing method thereof, wherein sintering of the outer peripheral surface of a shaft during pressing is reduced. A rotating electrical machine (100) is provided with a stator (10), a rotor (20), and a shaft (30). The rotor (20) is arranged with the 1 st rotor core (21a) and the 2 nd rotor core (21b) arranged in the axial direction. The 1 st rotor core (21a) is provided with 1 st recesses (212a) and 1 st protrusions (213a) alternately in the circumferential direction on the inner circumferential surface of a 1 st through hole (211a) into which a shaft (30) is press-fitted. The 2 nd rotor core (21b) is provided with 2 nd concave sections (212b) and 2 nd convex sections (213b) alternately in the circumferential direction on the inner circumferential surface of a 2 nd through hole (211b) into which the shaft (30) is press-fitted. When viewed from the axial direction, the 1 st rotor core (21a) and the 2 nd rotor core (21b) are arranged such that the 1 st recessed portion (212a) and the 2 nd raised portion (213b) are aligned, and the 1 st raised portion (213a) and the 2 nd recessed portion (212b) are aligned.

Description

Rotating electric machine and method for manufacturing same

Technical Field

The present invention relates to a rotating electric machine and a method of manufacturing the same.

Background

Conventionally, an inner rotor type rotating electrical machine is known in which a rotor is disposed radially inward of a stator and a shaft is fastened to the rotor. The rotor of the rotating electric machine described above includes a rotor core formed by laminating thin plates of a magnet and the magnet, and a through hole for fastening a shaft is formed in a radial center portion of the rotor core. The rotor is given a rotational torque by an electromagnetic force generated between the rotor and the stator, and rotates together with the shaft. In this case, a strong torsional strength is required at the fastening portion between the rotor and the shaft in order to transmit the rotational torque of the rotor to the shaft.

Press-fitting is one of methods for firmly fastening the rotor and the shaft, but there is a case where an error in the processing accuracy of the outer diameter of the shaft and the inner diameter of the rotor core becomes a problem at the time of press-fitting. For example, if the inner diameter of the rotor core is larger than the outer diameter of the shaft, the torsional strength of the fastening portion is insufficient, and the rotational torque is not transmitted to the shaft. Conversely, if the inner diameter of the rotor core is smaller than the outer diameter of the shaft, the shaft may buckle because the shaft is sintered on the outer peripheral surface of the shaft during press-fitting and the press-fitting load increases. In order to improve the machining accuracy of the rotor and the shaft, it is necessary to perform finishing such as polishing, but there is a problem that the manufacturing cost increases and the productivity deteriorates. On the other hand, for example, patent document 1 discloses a rotor structure in which a hole wall of a center hole of a rotor core is formed of a plurality of recesses and projections having a plurality of teeth, and when a shaft is pressed into the center hole, errors in machining accuracy are easily absorbed by deformation of the teeth.

Patent document 1: japanese laid-open patent publication No. 4-285446

Disclosure of Invention

However, when the portion where the shaft and the rotor core are in contact with each other is axially continuous, the outer peripheral surface of the shaft may slide along the inner peripheral surface of the rotor core as the shaft is pushed in, thereby causing seizure.

The present invention has been made to solve the above-described problems, and an object thereof is to provide a rotating electrical machine in which the seizure of the outer peripheral surface of the shaft at the time of press-fitting is reduced, and a method for manufacturing the rotating electrical machine.

The rotating electric machine according to the present invention includes: a shaft; a rotor having a 1 st rotor core and a 2 nd rotor core, the 1 st rotor core being formed by laminating a plurality of 1 st core pieces in series in an axial direction of a shaft, the inner peripheral surface of a 1 st through hole of a shaft is pressed into the radial central part of a 1 st chip, a 1 st convex part contacted with the shaft and a 1 st concave part not contacted with the shaft are alternately formed along the circumferential direction, the 2 nd rotor core part is formed by continuously laminating a plurality of 2 nd core pieces in the axial direction of the shaft, the inner circumferential surface of a 2 nd through hole of the shaft is pressed in the radial central part of the 2 nd core piece, a 2 nd convex part contacted with the shaft and a 2 nd concave part not contacted with the shaft are alternately formed along the circumferential direction, the 1 st rotor core part and the 2 nd rotor core part are arranged in the axial direction by respectively aligning the circumferential positions of the 1 st concave part and the 2 nd convex part and the circumferential positions of the 1 st convex part and the 2 nd concave part, and magnets are arranged along the circumferential direction of the 1 st rotor core part and the 2 nd rotor core part; and a stator disposed to face a radially outer side of the rotor.

Further, a method for manufacturing a rotating electric machine according to the present invention includes the steps of: a chip forming step of forming a 1 st through hole in the radial center portion of the 1 st chip by punching so that the 1 st concave portion and the 1 st convex portion are alternately provided in the circumferential direction on the inner circumferential surface, and forming a 2 nd through hole in the radial center portion of the 2 nd chip by punching so that the 2 nd concave portion and the 2 nd convex portion are alternately provided in the circumferential direction on the inner circumferential surface; a rotor core forming step of forming a 1 st rotor core by stacking a plurality of 1 st core pieces such that a 1 st concave portion and a 1 st convex portion are axially connected to each other, and forming a 2 nd rotor core by stacking a plurality of 2 nd core pieces such that a 2 nd concave portion and a 2 nd convex portion are axially connected to each other; a shaft press-fitting step of press-fitting a shaft into the 1 st through hole and the 2 nd through hole so that circumferential positions of the 1 st concave portion and the 2 nd convex portion and circumferential positions of the 1 st convex portion and the 2 nd concave portion are aligned with each other; a magnet bonding step of bonding magnets in the circumferential direction of the 1 st rotor core part and the 2 nd rotor core part; and a stator assembling step of assembling the stator so as to face the radial outer sides of the 1 st and 2 nd rotor cores.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the rotating electric machine of the present invention, the 1 st rotor core and the 2 nd rotor core are arranged in the axial direction with the circumferential positions of the 1 st concave portion and the 2 nd convex portion and the circumferential positions of the 1 st convex portion and the 2 nd concave portion aligned with each other, and therefore, the surface of the shaft that contacts the rotor core differs in the axial direction when the rotor core is press-fitted in the axial direction, and therefore, the seizure of the outer peripheral surface of the shaft can be reduced.

Further, according to the method of manufacturing a rotating electric machine according to the present invention, it is possible to arrange the 1 st rotor core and the 2 nd rotor core in the axial direction by aligning the circumferential positions of the 1 st concave portion and the 2 nd convex portion and the circumferential positions of the 1 st convex portion and the 2 nd concave portion through a simple process, and it is possible to reduce the seizure of the outer circumferential surface of the shaft.

Drawings

Fig. 1 is a cross-sectional view showing a schematic configuration of a rotating electric machine according to embodiment 1.

Fig. 2 is a side view showing a schematic configuration of a rotor and a shaft of a rotating electric machine according to embodiment 1.

Fig. 3 is a cross-sectional view showing a schematic structure of a rotor and a shaft of a rotating electric machine according to embodiment 1.

Fig. 4 is a cross-sectional view showing a schematic structure of a rotor core of a rotating electric machine according to embodiment 1.

Fig. 5 is a flowchart showing a manufacturing process of the rotating electric machine according to embodiment 1.

Fig. 6 is an explanatory diagram for explaining a method of manufacturing the rotating electric machine according to embodiment 1.

Fig. 7 is an explanatory diagram for explaining a method of manufacturing the rotating electric machine according to embodiment 1.

Fig. 8 is a cross-sectional view showing another example of a rotor core of the rotating electric machine according to embodiment 1.

Fig. 9 is a cross-sectional view showing another example of a rotor core of the rotating electric machine according to embodiment 1.

Fig. 10 is a cross-sectional view showing another example of a rotor core of the rotating electric machine according to embodiment 1.

Fig. 11 is a flowchart showing a manufacturing process of the rotating electric machine according to embodiment 2.

Fig. 12 is a cross-sectional view showing a schematic structure of a rotor core of a rotating electric machine according to embodiment 2.

Fig. 13 is an explanatory diagram for explaining a method of manufacturing a rotating electric machine according to embodiment 2.

Fig. 14 is a cross-sectional view showing a schematic structure of a rotor core of a rotating electric machine according to embodiment 3.

Fig. 15 is an explanatory diagram for explaining a method of manufacturing a rotating electric machine according to embodiment 3.

Fig. 16 is an explanatory diagram for explaining a method of manufacturing a rotating electric machine according to embodiment 3.

Fig. 17 is a cross-sectional view showing a schematic configuration of a rotor and a shaft of a rotating electric machine according to embodiment 4.

Fig. 18 is a side sectional view showing a schematic configuration of a rotor and a shaft of a rotating electric machine according to embodiment 5.

Fig. 19 is a cross-sectional view showing a schematic configuration of a rotor and a shaft of a rotating electric machine according to embodiment 5.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. Next, a case where the rotating electric machine is an electric motor will be described as an example.

Embodiment 1.

Fig. 1 is a cross-sectional view showing a schematic configuration of a rotating electric machine according to embodiment 1. As shown in fig. 1, rotating electric machine 100 is an inner rotor type and includes: a cylindrical stator 10; a rotor 20 disposed to face the radially inner side of the stator 10 via a predetermined air gap; and a shaft 30 fastened to the radially inner side of the rotor 20 and rotatably supported.

The rotating electric machine 100 rotates the rotor 20 and the shaft 30 by interaction between the magnetic field generated by the stator 10 and the magnetic field generated by the rotor 20. In the following description, the direction along the rotation axis of the shaft 30 is referred to as an axial direction, the direction perpendicular to the rotation axis of the shaft 30 is referred to as a radial direction, and the directions in which the rotor 20 and the shaft 30 rotate are referred to as circumferential directions.

The stator 10 has: a stator core 11 formed by laminating thin plates of a magnet in an axial direction; and a coil 12 formed by winding a conductor wire of copper or aluminum around the stator core 11.

The rotor 20 has: a rotor core 21 formed by laminating thin plates of a magnet in an axial direction; and magnets 22 provided along the circumferential direction of the rotor core 21. The magnets 22 are magnetized with N poles and S poles alternately in the circumferential direction on the outer peripheral surface of the rotor core 21, for example.

The shaft 30 is fastened to the radially inner side of the rotor 20 coaxially with the rotor 20, and is supported by a bearing 101 so as to be rotatable together with the rotor 20.

Fig. 2 is a side view showing a schematic configuration of a rotor and a shaft of a rotating electric machine according to embodiment 1. In fig. 2 and the following drawings, a part of the magnet 22 and the like is omitted for simplicity. As shown in fig. 2, the rotor core 21 has a 1 st rotor core 21a and a 2 nd rotor core 21b arranged in line in the axial direction of the shaft 30. The 1 st rotor core 21a and the 2 nd rotor core 21b are arranged to be in close contact with each other.

Fig. 3 is a cross-sectional view showing a schematic structure of a rotor and a shaft of a rotating electric machine according to embodiment 1. Fig. 3A is a sectional view taken along line a-a 'of fig. 2, and fig. 3B is a sectional view taken along line B-B' of fig. 2. As shown in fig. 3A, the 1 st rotor core 21a has a 1 st through hole 211a in a radial center portion thereof, into which the shaft 30 is press-fitted. On the inner circumferential surface of the 1 st through hole 211a, a plurality of 1 st concave portions 212a and 1 st convex portions 213a extending in the axial direction are alternately provided in the circumferential direction. In a state where the shaft 30 is press-fitted into the 1 st through hole 211a, the 1 st convex portion 213a is in contact with the shaft 30 to fix the shaft 30, and the 1 st concave portion 212a is not in contact with the shaft 30.

The 1 st recesses 212a preferably have 1 width and are arranged at equal intervals in the circumferential direction. Similarly, the 1 st convex portions 213a are preferably arranged so that 1 has the same width and the same interval in the circumferential direction. This makes it possible to uniformly apply the load for tightening the shaft 30 in the circumferential direction. Here, the equal width means not only a case where the widths are completely the same but also a case where the widths are equal within a predetermined error range. The equal intervals refer to not only the case where the distances are completely equal but also the case where the distances are equal within a predetermined error range. In the following description, the same applies to the case where the widths are equal or the same interval is described.

The 1 st rotor core 21a has 1 st positioning holes 214a at least 2 locations separated in the circumferential direction in the plane. The 1 st positioning hole 214a penetrates in the axial direction of the 1 st rotor core 21 a. When the shaft 30 is pressed in, the 1 st rotor core 21a performs positioning of the 1 st concave portion 212a and the 1 st convex portion 213a in the circumferential direction based on the 1 st positioning hole 214 a.

As shown in fig. 3B, the 2 nd rotor core portion 21B has a 2 nd through hole 211B that press-fits the shaft 30 in a radial center portion thereof. On the inner circumferential surface of the 2 nd through hole 211b, a plurality of 2 nd concave portions 212b and 2 nd convex portions 213b extending in the axial direction are alternately provided in the circumferential direction. In a state where the shaft 30 is press-fitted into the 2 nd through hole 211b, the 2 nd convex portion 213b is in contact with the shaft 30 to fix the shaft 30, and the 2 nd concave portion 212b is not in contact with the shaft 30.

The 2 nd recesses 212b preferably have 1 width and are arranged at equal intervals in the circumferential direction. Similarly, the 2 nd convex portions 213b are preferably arranged so that 1 has the same width and at equal intervals in the circumferential direction. This makes it possible to uniformly apply the load for tightening the shaft 30 in the circumferential direction.

The 2 nd rotor core 21b has 2 nd positioning holes 214b at least at 2 locations separated in the circumferential direction in the plane. The 2 nd positioning hole 214b penetrates in the axial direction of the 2 nd rotor core 21 b. When the shaft 30 is pressed in, the 2 nd rotor core portion 21b performs positioning of the 2 nd concave portion 212b and the 2 nd convex portion 213b in the circumferential direction based on the 2 nd positioning hole 214 b.

The 1 st recessed portion 212a of the 1 st rotor core 21a and the 2 nd raised portion 213b of the 2 nd rotor core 21b are formed to have, for example, the same width and the same number as each other. The 1 st projection 213a of the 1 st rotor core 21a and the 2 nd recess 212b of the 2 nd rotor core 21b are formed to have, for example, the same width and the same number.

The 1 st rotor core portion 21a and the 2 nd rotor core portion 21b are arranged with their circumferential positions aligned with each other when viewed from the axial direction of the shaft 30, i.e., with the 1 st positioning hole 214a and the 2 nd positioning hole 214b being aligned with each other. At this time, the circumferential positions of the 1 st recessed portion 212a of the 1 st rotor core 21a and the 2 nd raised portion 213b of the 2 nd rotor core 21b are aligned. In addition, the circumferential positions of the 1 st convex portion 213a of the 1 st rotor core 21a and the 2 nd concave portion 212b of the 2 nd rotor core 21b are aligned.

That is, in the circumferential range where the circumferential range of the 1 st convex portion 213a and the circumferential range of the 2 nd concave portion 212b overlap, the surface of the shaft 30 including the contact surface with the 1 st convex portion 213a only contacts the 1 st convex portion 213a when viewed from the axial end portion of the shaft 30. In a circumferential range where the circumferential range of the 2 nd convex portion 213b and the circumferential range of the 1 st concave portion 212a overlap, the surface of the shaft 30 including the contact surface of the shaft 30 with the 2 nd convex portion 213b contacts only the 2 nd convex portion 213b as viewed from the axial end portion of the shaft 30.

As described above, the 1 st rotor core 21a and the 2 nd rotor core 21b are arranged in the axial direction with the circumferential positions of the 1 st concave portion 212a and the 2 nd convex portion 213b and the circumferential positions of the 1 st convex portion 213a and the 2 nd concave portion 212b aligned with each other, and thus, when the shaft 30 is press-fitted, the surfaces of the shaft 30 that contact the rotor core 21 are different in the axial direction, and therefore, the occurrence of seizure on the outer peripheral surface of the shaft 30 can be reduced at the time of press-fitting.

Here, the circumferential positions of the 1 st concave portion 212a and the 2 nd convex portion 213b and the circumferential position alignment of the 1 st convex portion 213a and the 2 nd concave portion 212b may not completely match each other in shape and width.

For example, the width of the 1 st recess 212a may be greater than the width of the 2 nd protrusion 213b, and the width of the 2 nd recess 212b may be greater than the width of the 1 st protrusion 213 a. As described above, the 1 st concave portion 212a and the 2 nd concave portion 212b which are not in contact with the shaft 30 have widths larger than the 2 nd convex portion 213b and the 1 st convex portion 213a which are in contact with the shaft 30, respectively, whereby the 1 st convex portion 213a and the 2 nd convex portion 213b can be prevented from overlapping and being sintered on the outer peripheral surface of the shaft 30 due to a dimensional error at the time of machining, an assembly tolerance generated at the time of assembling the rotor core 21, and the like. Even if the width of the 1 st concave portion 212a and the width of the 2 nd concave portion 212b, which are not in contact with the shaft 30, are larger than the width of the 2 nd convex portion 213b and the width of the 1 st convex portion 213a, which are in contact with the shaft 30, respectively, if the 1 st convex portion 213a and the 2 nd convex portion 213b are partially overlapped, there is an effect of preventing the occurrence of the seizure on the outer peripheral surface of the shaft 30.

Next, an example of the circumferential positions of the 1 st positioning hole 214a and the 2 nd positioning hole 214b of the 1 st rotor core 21a and the 2 nd rotor core 21b will be described. Fig. 4 is a cross-sectional view showing a schematic structure of a rotor core of a rotating electric machine according to embodiment 1. Fig. 4A shows a sectional view of the 1 st rotor core, and fig. 4B shows a sectional view of the 2 nd rotor core.

The 1 st rotor core portion 21a and the 2 nd rotor core portion 21b are formed so that the outer shape and the shapes of the 1 st through hole 211a and the 2 nd through hole 211b are equal to each other except for the circumferential positions of the 1 st positioning hole 214a and the 2 nd positioning hole 214 b. That is, the width and number of the 1 st concave portion 212a and the 1 st convex portion 213a of the 1 st rotor core 21a are formed to be equal to the width and number of the 2 nd concave portion 212b and the 2 nd convex portion 213b of the 2 nd rotor core 21 b.

The 1 st recessed portions 212a and the 1 st raised portions 213a are formed at equal intervals, for example, in an even number. Similarly, the 2 nd concave portions 212b and the 2 nd convex portions 213b are formed at equal intervals, for example, in an even number. Here, although fig. 4 shows an example in which the 1 st concave portion 212a and the 1 st convex portion 213a, and the 2 nd concave portion 212b and the 2 nd convex portion 213b are formed in 4, the number may be 2 or more and 4 or more.

As shown in fig. 4A, 2 positioning holes 214A of the 1 st rotor core 21a are provided at positions facing each other with the rotation center O therebetween. The respective centers of the 21 st positioning holes 214a are disposed on, for example, a straight line P passing between the 1 st concave portion 212a and the 1 st convex portion 213a adjacent in the counterclockwise direction from the rotation center O. The 1 st positioning hole 214a is provided in the above manner, whereby the 1 st concave portion 212a and the 1 st convex portion 213a are arranged in an inverted manner with respect to the straight line P. The rotation center O here refers to the axial center of the shaft 30 or the axial center of the rotor 20 coaxial with the shaft 30.

Similarly, as shown in fig. 4B, 2 positioning holes 214B of the 2 nd rotor core portion 21B are provided at positions facing each other with the rotation center O therebetween. The respective centers of the 2 nd positioning holes 214b are disposed on, for example, a straight line P passing between the 2 nd concave portion 212b and the 2 nd convex portion 213b adjacent in the clockwise direction from the rotation center O. The 2 nd positioning hole 214b is provided in the above manner, whereby the 2 nd concave portion 212b and the 2 nd convex portion 213b are arranged in an inverted manner with respect to the straight line P.

The 1 st rotor core portion 21a and the 2 nd rotor core portion 21b are arranged so as to be line-symmetrical with respect to the straight line P when the straight line P is aligned so that the circumferential positions of the 1 st positioning hole 214a and the 2 nd positioning hole 214b are aligned when viewed from the axial direction of the shaft 30. That is, the 1 st recessed portion 212a of the 1 st rotor core 21a and the 2 nd recessed portion 212b of the 2 nd rotor core 21b are symmetrically disposed with respect to the straight line P, and the 1 st protruding portion 213a of the 1 st rotor core 21a and the 2 nd protruding portion 213b of the 2 nd rotor core 21b are symmetrically disposed with respect to the straight line P.

By disposing the 1 st positioning hole 214a and the 2 nd positioning hole 214b in this manner, one of the 1 st rotor core 21a and the 2 nd rotor core 21b is inverted to have the same shape as the other. Therefore, the 1 st rotor core portion 21a and the 2 nd rotor core portion 21b can be manufactured using the same mold as described in the following manufacturing method.

As described above, in the rotating electric machine 100 according to embodiment 1, the 1 st rotor core 21a and the 2 nd rotor core 21b are arranged in the axial direction with the circumferential positions of the 1 st concave portion 212a and the 2 nd convex portion 213b and the circumferential positions of the 1 st convex portion 213a and the 2 nd concave portion 212b aligned with each other. Thus, when the shaft 30 is press-fitted into the rotor core 21, the surface of the shaft 30 that contacts the rotor core 21 differs in the axial direction. This can reduce the occurrence of seizure due to deterioration of surface roughness caused by the sliding between the outer peripheral surface of the shaft 30 and the inner peripheral surface of the rotor core 21. Therefore, the shaft 30 can be prevented from buckling due to an increase in press-fitting load caused by sintering.

Next, a method of manufacturing the rotating electric machine 100 will be described. Fig. 5 is a flowchart showing a manufacturing process of the rotating electric machine according to embodiment 1.

First, the 1 ST core piece 210a and the 2 nd core piece 210b constituting the 1 ST rotor core portion 21a and the 2 nd rotor core portion 21b are formed into a plurality of pieces, respectively (a core piece forming step ST 101). The 1 st and 2 nd core pieces 210a and 210b are thin plates of a magnet, and are formed by punching or laser punching a predetermined shape, such as an iron Plate or a silicon steel Plate of spcc (steel Plate Cold commercial). The shape of the 1 st core piece 210a and the 2 nd core piece 210B is the same as the cross-sectional shape of the 1 st rotor core 21a and the 2 nd rotor core 21B shown in fig. 4A and 4B.

The 1 st chip 210a has a 1 st through hole 211a at a radially central portion, and the 1 st through hole 211a is punched so that a 1 st concave portion 212a and a 1 st convex portion 213a are alternately provided in a circumferential direction on an inner circumferential surface. The 2 nd chip 210b has a 2 nd through hole 211b at a radial center portion, and the 2 nd through hole 211b is punched out so that a 2 nd concave portion 212b and a 2 nd convex portion 213b are alternately provided in a circumferential direction on an inner circumferential surface.

The 1 st chip 210a and the 2 nd chip 210b are formed such that the inner diameter of a circle connecting the radially inner front end portions of the 1 st convex portion 213a and the inner diameter of a circle connecting the radially inner front end portions of the 2 nd convex portion 213b, which are provided in a plurality in the circumferential direction, are smaller than the outer diameter of the shaft 30 by the press-fitting fastening amount (about 0.01 to 0.2mm with respect to the radius), respectively. The inner diameter of the circle connecting the radially inner front ends of the 1 st concave portion 212a and the inner diameter of the circle connecting the radially inner front ends of the 2 nd concave portion 212b are formed to be larger than the outer diameter of the shaft 30 by about 0.03 to 1mm with respect to the radius.

The 1 st chip 210a and the 2 nd chip 210b are punched out so as to have a 1 st positioning hole 214a and a 2 nd positioning hole 214b at 2 locations separated in the in-plane circumferential direction, respectively. The 1 st chip 210a and the 2 nd chip 210b are formed so that the outer shape, the thickness, and the like of the 1 st through hole 211a and the 2 nd through hole 211b are equal to each other except for the circumferential positions of the 1 st positioning hole 214a and the 2 nd positioning hole 214 b.

The 1 st positioning hole 214a is formed on, for example, a straight line P passing between the 1 st concave portion 212a and the 1 st convex portion 213a adjacent in the counterclockwise direction from the rotation center O. In addition, the 2 nd positioning hole 214b is formed, for example, on a straight line P passing between the 2 nd concave portion 212b and the 2 nd convex portion 213b adjacent in the clockwise direction from the rotation center O. As described above, by forming the 1 st positioning hole 214a and the 2 nd positioning hole 214b, one of the 1 st chip 210a and the 2 nd chip 210b is turned over to have the same shape as the other. Therefore, the 1 st chip 210a and the 2 nd chip 210b can be formed using the same mold.

Next, a plurality of the 1 ST core pieces 210a and the 2 nd core pieces 210b are stacked in the thickness direction, respectively, to form the 1 ST rotor core portion 21a and the 2 nd rotor core portion 21b (rotor core forming step ST 102). The 1 st chip 210a is stacked such that the 1 st recess 212a and the 1 st projection 213a are axially connected to each other by aligning the circumferential positions of the 1 st positioning holes 214 a. Similarly, the 2 nd chip 210b is stacked such that the 2 nd concave portion 212b and the 2 nd convex portion 213b are axially connected to each other by aligning the circumferential positions of the 2 nd positioning holes 214 b. The 1 st chip 210a and the 2 nd chip 210b are laminated and fixed to each other by means of hoop bonding, laser welding, adhesion, or the like.

Next, the 1 ST rotor core portion 21a and the 2 nd rotor core portion 21b are fixed to the press-fitting fixing tool 50, respectively, and the shaft 30 is press-fitted (shaft press-fitting step ST 103). Fig. 6 is an explanatory diagram for explaining a method of manufacturing the rotating electric machine according to embodiment 1. As shown in fig. 6, the press-fitting fixing tool 50 is provided with a hole into which the shaft 30 is inserted, and has 2 pins 51 corresponding to 21 st positioning holes 214a of the 1 st rotor core 21 a. Further, the press-fitting fixing tool 50 is supported to the vicinity of the radially inner front ends of the 1 st protruding portion 213a of the 1 st rotor core portion 21a and the 2 nd protruding portion 213b of the 2 nd rotor core portion 21b, and can receive a press-fitting load together with the plurality of stacked core pieces by the press-fitting fixing tool 50, and out-of-plane deformation can be suppressed.

The 1 st rotor core 21a is fixed in its circumferential position by inserting 2 pins 51 pressed into the fixing tool 50 into the 21 st positioning holes 214a, respectively. Then, the shaft 30 is press-fitted into the 1 st through hole 211a of the 1 st rotor core 21a at a fixed position. After press-fitting, both the 1 st rotor core 21a and the shaft 30 are removed from the press-fitting fixing tool 50.

Further, as shown in fig. 7, when the shaft 30 is press-fitted to the 1 st rotor core 21a, a portion 31a of the outer peripheral surface of the shaft 30, which is in contact with the 1 st convex portion 213a of the 1 st rotor core 21a, drags and slides on the 1 st rotor core 21a, and the surface becomes rough. On the other hand, in the portion 31b of the outer peripheral surface of the shaft 30 that passes without contacting the 1 st recess 212a of the 1 st rotor core 21a, the surface is not roughened, and the state before the 1 st rotor core 21a is pressed in is maintained.

Similarly to the 1 st rotor core 21a, the 2 nd rotor core 21b fixes the circumferential position by inserting 2 pins 51 provided in the press-fitting fixing tool 50 into 2 nd positioning holes 214b, respectively. Then, the shaft 30 into which the 1 st rotor core 21a has been press-fitted is press-fitted to the 2 nd through hole 211b of the 2 nd rotor core 21b at a fixed position.

The shaft 30 is press-fitted so as to pass through the 2 nd recessed portion 212b of the 2 nd rotor core 21b without contacting the 1 st recessed portion 213a of the 1 st rotor core 21a in the portion 31a that is in contact with the 1 st recessed portion 212a of the 1 st rotor core 21a, and pass through the 2 nd raised portion 213b of the 2 nd rotor core 21b without contacting the 1 st recessed portion 212 a. At this time, the shaft 30 controls the position in the axial direction so that one end surface of the 1 st rotor core portion 21a and one end surface of the 2 nd rotor core portion 21b are in close contact with each other.

As described above, by press-fitting the shaft 30 by separating the 1 st rotor core 21a and the 2 nd rotor core 21b, the press-fitting length at one time can be shortened, the press-fitting load can be reduced, and buckling of the shaft 30 can be suppressed at the time of press-fitting.

Next, as shown in fig. 5, magnets 22 having N poles and S poles alternately magnetized in the circumferential direction are attached to the outer circumferential surfaces of the 1 ST rotor core 21a and the 2 nd rotor core 21b via an adhesive to form a rotor 20 (magnet bonding step ST 104).

Finally, the stator 10 is assembled to the outside in the radial direction of the rotor 20 and the shaft 30 (stator assembling step ST 105). The rotating electric machine 100 is manufactured in the above-described manner. Here, the order of part of the steps ST101 to ST105 may be omitted or replaced, and for example, the magnet 22 may be attached (step ST104) before the shaft 30 is press-fitted (step ST 103). The 1 st chip 210a and the 2 nd chip 210b may be fixed to each other by press-fitting the shaft 30.

Further, although the example in which the shaft 30 is press-fitted into the 1 st rotor core 21a and then the shaft 30 is press-fitted into the 2 nd rotor core 21b is shown, the 1 st rotor core 21a and the 2 nd rotor core 21b may be arranged in the press-fitting fixing jig 50 in the axial direction in advance, and the shaft 30 may be press-fitted at one time.

According to this manufacturing method, the 1 st rotor core 21a and the 2 nd rotor core 21b can be arranged in the axial direction by aligning the circumferential positions of the 1 st concave portion 212a and the 2 nd convex portion 213b and the circumferential positions of the 1 st convex portion 213a and the 2 nd concave portion 212b, respectively, through a simple process. This can reduce the occurrence of seizure on the outer peripheral surface of the shaft 30 in the step of press-fitting the shaft 30, and can suppress buckling of the shaft 30 due to an increase in press-fitting load. Therefore, the manufacturing cost for improving the machining accuracy of the outer diameter of the shaft 30 and the inner diameter of the rotor core 21 can be reduced, and the productivity can be improved.

Further, when one of the 1 st chip 210a and the 2 nd chip 210b is turned upside down, the same shape as the other is formed, so that the same mold can be used for manufacturing, the cost of the mold can be reduced, and the productivity can be improved.

Further, since the rotor core in which the plurality of core pieces are stacked is press-fitted, the plurality of core pieces receive the press-fitting load, and thereby the out-of-plane deformation of the core pieces can be suppressed. Therefore, a reduction in fastening torque of the shaft and the rotor core caused by the out-of-plane deformation of the core pieces is prevented. Further, it is not necessary to add a step for improving the machining accuracy of the outer diameter of the shaft 30 and the inner diameter of the rotor core 21, and the rotating electric machine 100 can be manufactured with high productivity at a reduced manufacturing cost.

Further, when the shaft 30 is press-fitted into the 1 st rotor core 21a, even if burrs are generated at the axial end portions of the 1 st protruding portion 213a of the 1 st rotor core 21a that are in contact with the shaft 30 or the out-of-plane deformation of the 1 st core piece 210a and the 2 nd core piece 210b that are stacked occurs, the burrs or the out-of-plane deformation portions are located in the 2 nd recessed portion 212b of the 2 nd rotor core 21b, and therefore, the 1 st rotor core 21a and the 2 nd rotor core 21b can be press-fitted without a gap.

Further, as an example of embodiment 1, the 1 st rotor core 21a shows an example in which the width of the 1 st recessed portion 212a and the width of the 1 st raised portion 213a are equal to each other, but as shown in fig. 8, for example, the width of the 1 st raised portion 213a may be made smaller than the width of the 1 st recessed portion 212a in a range in which a load sufficient to fasten the shaft 30 can be applied. At this time, the width of the 2 nd recessed portion 212b of the 2 nd rotor core 21b is formed to be equal to the width of the 1 st raised portion 213a of the 1 st rotor core 21a, and the width of the 2 nd raised portion 213b of the 2 nd rotor core 21b is formed to be equal to the width of the 1 st recessed portion 212a of the 1 st rotor core 21 a.

In the above-described configuration, the circumferential positions of the 1 st concave portion 212a and the 2 nd convex portion 213b and the circumferential positions of the 1 st convex portion 213a and the 2 nd concave portion 212b may be arranged so as to be aligned with each other when viewed from the axial direction of the shaft 30.

Further, as an example of embodiment 1, an example is shown in which the 1 st positioning hole 214a and the 2 nd positioning hole 214b are provided so that the 1 st rotor core portion 21a and the 2 nd rotor core portion 21b are formed in the same shape as the other by turning one of them, but the arrangement of the 1 st positioning hole 214a and the 2 nd positioning hole 214b is not limited to this. For example, as shown in fig. 9A, 21 st positioning holes 214a may be provided in the 1 st rotor core 21a on a straight line M passing through the center position of the 1 st concave portion 212a facing each other with the rotation center O interposed therebetween, and as shown in fig. 9B, 2 nd positioning holes 214B may be provided in the 2 nd rotor core 21B on a straight line N passing through the center position of the 2 nd convex portion 213B facing each other with the rotation center O interposed therebetween. Here, the center position of the 1 st concave portion 212a means a position where the length of the arc of the 1 st concave portion 212a formed along the 1 st through hole 211a is half. The same applies to the center position of the 2 nd convex portion 213 b.

In the above-described configuration, when viewed from the axial direction of the shaft 30, the circumferential positions of the 1 st positioning hole 214a and the 2 nd positioning hole 214b are aligned, and the straight lines M and N are aligned, whereby the circumferential positions of the 1 st concave portion 212a and the 2 nd convex portion 213b and the circumferential positions of the 1 st convex portion 213a and the 2 nd concave portion 212b can be also aligned and arranged, respectively.

In addition, as an example of embodiment 1, an example in which 2 positioning holes 214a and 214b are provided for each of the 1 st positioning hole and the 2 nd positioning hole is shown, but the number may be 2 or more. For example, as shown in fig. 10, the 1 st rotor core 21a and the 2 nd rotor core 21b may have 41 st positioning holes 214a and 2 nd positioning holes 214b, respectively. At this time, as shown in fig. 10A, 2 positioning holes 214a are provided on a straight line M passing through the center position of the 1 st recess 212a from the rotation center O with the rotation center O therebetween. Further, 2 straight lines N passing through the rotation center O and the center position of the 1 st convex portion 213a are provided with the rotation center O therebetween. Similarly, as shown in fig. 10B, the 2 nd rotor core portion has 42 nd positioning holes 214B, and 2 second positioning holes 214B are provided on a straight line M passing through the center position of the 2 nd recess 212B from the rotation center O with the rotation center O interposed therebetween. Further, 2 convex portions 213b are provided on a straight line N passing through the rotation center O and the center position of the 2 nd convex portion 213b with the rotation center O interposed therebetween.

The 1 st rotor core 21a and the 2 nd rotor core 21b are arranged in the axial direction so as to align the straight line M of the 1 st rotor core 21a and the straight line N of the 2 nd rotor core 21b, and when the shaft 30 is pressed, the surfaces that contact the rotor cores 21 are different in the axial direction, so that the shaft 30 can be easily pressed. By providing 4 positioning holes 214a and 214b, respectively, the 1 st rotor core portion 21a and the 2 nd rotor core portion 21b are rotationally symmetric with respect to the rotation center O, and can be manufactured using the same mold.

Embodiment 2.

A rotating electric machine 100 according to embodiment 2 will be described. The same points as those in embodiment 1 will not be described below, and the differences will be mainly described.

Fig. 11 is a cross-sectional view showing a schematic structure of a rotor core of a rotating electric machine according to embodiment 2. Fig. 11A is a sectional view of the 1 st rotor core 21A, and fig. 11B is a sectional view of the 2 nd rotor core 21B.

As shown in fig. 11A, the 1 st through-holes 211A of the 1 st rotor core 21A have, for example, 31 st recesses 212a and 1 st protrusions 213a, respectively, and the 1 st recesses 212a and the 1 st protrusions 213a have the same width and are alternately arranged at equal intervals. The 1 st recessed portions 212a and the 1 st raised portions 213a are formed to have the same number and the same width, for example. By forming in the above manner, when the 1 st rotor core 21a is rotated by 180 degrees with respect to the rotation center O, the 1 st concave portion 212a and the 1 st convex portion 213a are arranged in reverse to each other.

The 1 st positioning hole 214a is provided in 2 opposed positions with the rotation center O therebetween. The centers of the 21 st positioning holes 214a are provided on, for example, a straight line Q passing through the center position of the 1 st concave portion 212a and the center position of the 1 st convex portion 213a facing each other with the rotation center O therebetween.

As shown in fig. 11B, the 2 nd through holes 211B of the 2 nd rotor core portion 21B have, for example, 3 2 nd concave portions 212B and 2 nd convex portions 213B, respectively, and the 2 nd concave portions 212B and the 2 nd convex portions 213B have 1 equal width and are alternately arranged at equal intervals. The 2 nd recessed portions 212b and the 2 nd raised portions 213b are formed to have the same number and the same width, for example. By forming in the above manner, when the 2 nd rotor core 21b is rotated by 180 degrees with respect to the rotation center O, the 2 nd concave portion 212b and the 2 nd convex portion 213b are arranged in an inverted state with respect to each other.

The 2 nd positioning holes 214b are provided in 2 positions facing each other with the rotation center O interposed therebetween. The 2 nd positioning holes 214b are each provided at the center thereof on, for example, a straight line Q passing through the center position of the 2 nd concave portion 212b and the center position of the 2 nd convex portion 213b facing each other with the rotation center O interposed therebetween.

The 1 st rotor core 21a and the 2 nd rotor core 21b have the same outer shape and the 1 st through hole 211a and the 2 nd through hole 211b have the same shape, and when one of the 1 st rotor core 21a and the 2 nd rotor core 21b is rotated 180 degrees around the rotation center O or turned upside down, the other one has the same shape when viewed from the axial direction of the shaft 30.

When the 1 st rotor core 21a and the 2 nd rotor core 21b align the circumferential positions of the 1 st positioning hole 214a and the 2 nd positioning hole 214b and the straight lines Q match, the circumferential positions of the 1 st concave portion 212a and the 2 nd convex portion 213b are aligned, and the circumferential positions of the 1 st convex portion 213a and the 2 nd concave portion 212b are aligned.

Here, although the 1 st concave portion 212a and the 1 st convex portion 213a, and the 2 nd concave portion 212b and the 2 nd convex portion 213b are 3 pieces, the 1 st concave portion 212a and the 1 st convex portion 213a may be provided to face each other with respect to the rotation center O, and the 2 nd concave portion 212b and the 2 nd convex portion 213b may be provided to face each other with respect to the rotation center O of the 2 nd rotor core portion 21b, and the number may be an odd number greater than or equal to 3. In addition, although the example in which the 1 st positioning hole 214a and the 2 nd positioning hole 214b are provided on the straight line Q passing through the center positions of the 1 st concave portion 212a and the 1 st convex portion 213a and the center positions of the 2 nd concave portion 212b and the 2 nd convex portion 213b is shown, at least 2 positioning holes may be provided at positions facing each other with the rotation center O interposed therebetween.

As described above, in the rotating electric machine 100 according to embodiment 2, since the surfaces of the shaft 30 that contact the rotor core 21 differ in the axial direction when the shaft 30 is press-fitted, the occurrence of seizure on the outer peripheral surface of the shaft 30 can be reduced, and buckling of the shaft 30 can be suppressed. In the present embodiment, when one of the 1 st rotor core 21a and the 2 nd rotor core 21b is rotated 180 degrees around the rotation center O or turned upside down, the shape is the same as that of the other, and therefore, the 1 st rotor core 21a and the 2 nd rotor core 21b can be manufactured using the same mold, and the manufacturing cost can be further suppressed, and the productivity can be improved.

Next, a method for manufacturing rotating electric machine 100 according to embodiment 2 will be described. Here, the same portions as those in embodiment 1 will be described by simplification or omission. Fig. 12 is a flowchart showing a manufacturing process of the rotating electric machine according to embodiment 2.

The 1 ST chip 210a and the 2 nd chip 210b are formed into a plurality of chips (chip forming step ST 201). The 1 st chip 210a and the 2 nd chip 210b are formed by punching out a predetermined shape by press or laser processing using the same die. As shown in fig. 11A, when the 1 st chip 210a is rotated 180 degrees around the rotation center O, the 1 st concave portion 212a and the 1 st convex portion 213a are arranged in reverse to each other. Similarly, as shown in fig. 11B, when the 2 nd chip 210B is rotated 180 degrees around the rotation center O, the 2 nd concave portion 212B and the 2 nd convex portion 213B are arranged in an inverted state with respect to each other.

Next, a plurality of the 1 ST core pieces 210a and the 2 nd core pieces 210b are collectively stacked in the thickness direction to form the 1 ST rotor core portion 21a and the 2 nd rotor core portion 21b (rotor core forming step ST 202). The 1 ST chip 210a and the 2 nd chip 210b are collectively stacked without being distinguished from each other (chip stacking step ST202 a). The laminated core pieces are divided into 2 pieces corresponding to a predetermined lamination thickness, one piece is defined as a 1 ST rotor core portion 21a, and the other piece is defined as a 2 nd rotor core portion 21b rotated 180 degrees about a rotation center O with respect to the 1 ST rotor core portion 21a (laminated core piece rotating step ST202 b).

The 1 ST rotor core portion 21a and the 2 nd rotor core portion 21b are fixed to the press-fitting fixing tool 50, and the shaft 30 is press-fitted (shaft press-fitting step ST 203). Fig. 13 is an explanatory diagram for explaining a method of manufacturing a rotating electric machine according to embodiment 2. The 1 st rotor core portion 21a is disposed by inserting the pin 51 of the press-fitting fixing tool 50 through the 1 st positioning hole 214 a. The 2 nd rotor core 21b is arranged to be inserted through the 2 nd positioning hole 214b with the pin 51 of the press-fitting fixing tool 50 inserted therein, and to overlap the 1 st rotor core 21a in the axial direction. The shaft 30 is press-fitted into the 1 st through hole 211a of the 1 st rotor core 21a and the 2 nd through hole 211b of the 2 nd rotor core 21b at a time.

As described above, the 1 st rotor core portion 21a and the 2 nd rotor core portion 21b are arranged in line in the press-fitting fixing jig 50, and the shaft 30 is press-fitted at one time, whereby productivity can be improved as compared with a case where the shaft 30 is press-fitted individually.

The magnet 22 is attached to the outer peripheral surfaces of the 1 ST rotor core portion 21a and the 2 nd rotor core portion 21b via an adhesive to form the rotor 20 (magnet bonding step ST 204). The stator 10 is assembled to the radial outside of the rotor 20 and the shaft 30 (stator assembling step ST 205).

The rotating electric machine 100 is manufactured in the above-described manner. Here, the sequence of some of the steps ST201 to ST205 may be omitted or reversed. For example, the 1 st chip 210a and the 2 nd chip 210b are stacked and then rotated 180 degrees, but one of the 1 st chip 210a and the 2 nd chip 210b may be rotated 180 degrees and then stacked. Further, the 1 st rotor core 21a and the 2 nd rotor core 21b are arranged in the axial direction, and the shaft 30 is press-fitted at one time, but the 1 st rotor core 21a and the 2 nd rotor core 21b may be separately press-fitted.

Further, although the 2 nd rotor core 21b is defined as a rotor core rotated 180 degrees about the rotation center O with respect to the 1 st rotor core 21a, a rotor core turned upside down with respect to the 1 st rotor core 21a may be defined as the 2 nd rotor core 21 b.

As described above, in the method of manufacturing the rotating electric machine 100 according to embodiment 2, the circumferential positions of the 1 st concave portion 212a and the 2 nd convex portion 213b and the circumferential positions of the 1 st convex portion 213a and the 2 nd concave portion 212b can be aligned with each other by a simple process, and the shaft 30 can be easily press-fitted with reduced seizure occurring on the outer circumferential surface of the shaft 30. In the method of manufacturing the rotating electric machine 100 according to the present embodiment, the 1 st core piece 210a and the 2 nd core piece 210b can be punched out by the same die, and the manufacturing cost of the die can be reduced. Further, if the 1 st rotor core 21a and the 2 nd rotor core 21b are equal in lamination thickness, a plurality of the 1 st rotor cores 21a can be manufactured in advance, and the 1 st rotor core 21a can be rotated 180 degrees or turned over about the rotation center O to be used as the 2 nd rotor core 21b, so that the productivity can be further improved.

Embodiment 3.

Next, the rotating electric machine 100 according to embodiment 3 will be explained. The same points as those in embodiment 1 will not be described below, and the differences will be mainly described. In embodiment 1, an example is shown in which 2 holes provided separately in the circumferential direction of the 1 st positioning hole 214a and the 2 nd positioning hole 214b have the same shape, but in this embodiment, the shapes of the 2 holes are different from each other.

Fig. 14 is a cross-sectional view showing a schematic structure of a rotor core of a rotating electric machine according to embodiment 3. Fig. 14A is a sectional view of the 1 st rotor core, and fig. 14B is a sectional view of the 2 nd rotor core. As shown in fig. 14, the 1 st rotor core 21a includes 1 st and 2 nd holes 2141a and 2142a facing each other with different radii with respect to the rotation center O. Similarly, the 2 nd rotor core 21b has the 1 st hole 2141b and the 2 nd hole 2142b which are opposed to each other with the rotation center O therebetween and have different radii. The 1 st positioning hole is constituted by the 1 st hole 2141a and the 2 nd hole 2142a of the 1 st rotor core 21a, and the 2 nd positioning hole is constituted by the 1 st hole 2141b and the 2 nd hole 2142b of the 2 nd rotor core 21 b.

Fig. 15 and 16 are explanatory views for explaining a method of manufacturing a rotating electric machine according to embodiment 3. As shown in fig. 15, when the shaft 30 is pressed into the 1 st rotor core 21a, the 1 st pin 51a and the 2 nd pin 52a of the press-fitting fixing tool 50a are inserted into the 1 st hole 2141a and the 2 nd hole 2142a, respectively, and the circumferential positions thereof are fixed. Similarly, as shown in fig. 16, when the shaft 30 is press-fitted into the 2 nd rotor core 21b, the 1 st pin 51b and the 2 nd pin 52b of the press-fitting fixing tool 50b are inserted into the 1 st hole 2141b and the 2 nd hole 2142b, respectively, and the circumferential positions thereof are fixed.

As described above, the 1 st positioning hole 214a has the 1 st hole 2141a and the 2 nd hole 2142a having different radii and facing each other with the rotation center O interposed therebetween, and the 2 nd positioning hole 214b has the 1 st hole 2141b and the 2 nd hole 2142b having different radii and facing each other with the rotation center O interposed therebetween, whereby the press-fitting fixing tools 50a and 50b can be fixed at appropriate circumferential positions, and workability can be improved, and productivity can be further improved.

Here, as shown in fig. 14A, it is preferable that the 1 st hole 2141a and the 2 nd hole 2142a of the 1 st rotor core 21a satisfy formula (1) if the radius of the 1 st hole 2141a is R1, the radius of the 2 nd hole 2142a is R2, the distance from the rotation center O to the center of the 1 st hole 2141a is R1, and the distance from the rotation center O to the center of the 2 nd hole 2142a is R2.

[ formula 1 ]

Wherein R1 ≠ R2, and R1 ≠ R2.

That is, the product of the square of the radius R1 of the 1 st hole 2141a and the distance R1 from the center of the 1 st hole 2141a to the rotation center O is equal to the product of the square of the radius R2 of the 2 nd hole 2142a and the distance R2 from the center of the 2 nd hole 2142a to the rotation center O. As described above, the nonuniformity of the mass distributions of the 1 st and 2 nd holes 2141a and 2142a (hereinafter, referred to as imbalance) due to the formation of the 1 st and 2 nd holes 2141a and 2142a is offset, and vibration and noise caused by centrifugal force can be prevented when the rotor 20 rotates.

For example, if the lamination thickness of the 1 st rotor core 21a is H and the material density is ρ, the unbalance U1 occurring in the 1 st hole 2141a in the 1 st rotor core 21a is expressed by equation (2).

[ formula 2 ]

Similarly, the imbalance U2 related to the 2 nd hole 2142a in the 1 st rotor core 21a is expressed by equation (3).

[ formula 3 ]

By satisfying the formula (1), the formula (2) and the formula (3) result in U1 being equal to U2, and the imbalance between the 1 st hole 2141a and the 2 nd hole 2142a is cancelled out.

Similarly, the 1 st hole 2141b and the 2 nd hole 2142b of the 2 nd rotor core 21b are also formed to satisfy the relationship of the formula (1), whereby the imbalance of the 2 nd rotor core 21b is cancelled, and vibration and noise due to a centrifugal force can be prevented when the rotor 20 rotates.

As described above, in the rotating electric machine 100 according to embodiment 3, since the surfaces of the shaft 30 that contact the rotor core 21 differ in the axial direction when the shaft 30 is press-fitted, the occurrence of seizure on the outer peripheral surface of the shaft 30 can be reduced, and buckling of the shaft 30 can be suppressed.

In the rotating electric machine 100 according to embodiment 3, the 21 st positioning holes 214a of the 1 st rotor core 21a are different in shape from each other, and the 2 nd positioning holes 214b of the 2 nd rotor core 21b are different in shape from each other. Thus, when the shaft 30 is pressed in, it is possible to easily distinguish which of the 1 st pin 51a and the 2 nd pin 52b of the press-fitting fixing tool 50 the 1 st hole 2141a and the 2 nd hole 2142a of the 1 st rotor core 21a correspond to. Similarly, it is possible to easily distinguish which of the 1 st pin 51b and the 2 nd pin 52b of the press-fitting fixing tool 50 corresponds to the 1 st hole 2141b and the 2 nd hole 2142b of the 2 nd rotor core 21 b. This makes it easy to dispose the 1 st rotor core 21a and the 2 nd rotor core 21b at appropriate circumferential positions, thereby improving workability and productivity.

In the rotating electric machine 100 according to embodiment 3, the 1 st positioning hole 214a and the 2 nd positioning hole 214b each have 2 holes, and the product of the radius of one of the 2 holes and the distance from the center of the one hole to the rotation center is equal to the product of the radius of the other hole and the distance from the center of the other hole to the rotation center, whereby it is possible to prevent the occurrence of vibration and noise due to centrifugal force caused by unbalance when the rotor 20 rotates, and it is possible to provide a high-quality rotating electric machine 100.

In embodiment 3, the 2 holes of the 1 st positioning hole 214a and the 2 nd positioning hole 214b are circular and have different radii, but the 2 holes may have different shapes to the extent that they can be distinguished from each other, and for example, one of the 2 holes may be circular and the other may be square. At this time, it is preferable to decide the size of 2 holes so that the unbalance is cancelled out.

Embodiment 4.

A rotating electric machine 100 according to embodiment 4 will be described. The same points as those in embodiment 1 will not be described below, and the differences will be mainly described. In embodiment 1, the 1 st through hole 211a and the 2 nd through hole 211b have a shape having a corner, but in this embodiment, have a continuous curved surface.

Fig. 17 is a cross-sectional view showing a schematic configuration of a rotor and a shaft of a rotating electric machine according to embodiment 4. Fig. 17A is a sectional view of the 1 st rotor core and the shaft, and fig. 17B is a sectional view of the 2 nd rotor core and the shaft. As shown in fig. 17, the 1 st rotor core 21a has the inner peripheral surface of the 1 st through hole 211a forming the 1 st concave portion 212a and the 1 st convex portion 213a formed by a continuous curved surface. Similarly, the 2 nd rotor core 21b has the inner peripheral surface of the 2 nd through hole 211b forming the 2 nd concave portion 212b and the 2 nd convex portion 213b formed of a continuous curved surface.

When viewed from the axial direction of the shaft 30, the 1 st rotor core 21a and the 2 nd rotor core 21b are arranged such that the circumferential positions of the 1 st concave portion 212a and the 2 nd convex portion 213b are aligned and the circumferential positions of the 1 st convex portion 213a and the 2 nd concave portion 212b are aligned and aligned in the axial direction.

As described above, in the rotating electric machine 100 according to embodiment 4, when the shaft 30 is pressed in, the surface of the shaft 30 that contacts the rotor core 21 is different in the axial direction, so that the occurrence of seizure on the outer peripheral surface of the shaft 30 can be reduced, and buckling of the shaft 30 can be suppressed.

In embodiment 4, by forming the inner circumferential surfaces of the 1 st through hole 211a of the 1 st rotor core 21a and the 2 nd through hole 211b of the 2 nd rotor core 21b with continuous curved surfaces, it is possible to prevent stress generated when the shaft 30 is press-fitted from concentrating at the corner portions, and to suppress out-of-plane deformation of the 1 st core piece 210a and the 2 nd core piece 210b forming the 1 st rotor core 21a and the 2 nd rotor core 21 b.

Embodiment 5.

A rotating electric machine 100 according to embodiment 5 will be described. The same points as those in embodiment 1 will not be described below, and the differences will be mainly described. In embodiment 1, 2 rotor cores of the 1 st rotor core 21a and the 2 nd rotor core 21b are press-fitted into the shaft 30, but 3 or more rotor cores of the 1 st rotor core 21a, the 2 nd rotor core 21b, and the 3 rd rotor core 21c may be press-fitted into the shaft 30. Next, a structure in which 3 rotor cores are press-fitted into the shaft 30 will be described.

Fig. 18 is a side sectional view showing a schematic configuration of a rotor and a shaft of a rotating electric machine according to embodiment 5.

Fig. 19 is a cross-sectional view showing a schematic configuration of a rotor and a shaft of a rotating electric machine according to embodiment 5. Fig. 19A is a sectional view of the 1 st rotor core and shaft taken along the line a-a ' of fig. 18, fig. 19B is a sectional view of the 2 nd rotor core and shaft taken along the line B-B ' of fig. 18, and fig. 19C is a sectional view of the 3 rd rotor core and shaft taken along the line C-C ' of fig. 18.

As shown in fig. 19A, the 1 st through hole 211a of the 1 st rotor core 21a has a total of the 1 st convex portion 213a occupying about 120 ° which is one third of the circumference, and a total of the 1 st concave portion 212a occupying about 240 ° which is two thirds of the circumference. For example, the 1 st convex portion 213a and the 1 st concave portion 212a are 3 each, and when the widths of the 31 st convex portions 213a are equal and the widths of the 31 st concave portions 212a are equal, the width of the 1 st convex portion 213a is 40 °, and the width of the 1 st concave portion 212a is 80 °.

Similarly, as shown in fig. 19B, 1 width of the 2 nd convex portion 213B formed in the 2 nd through hole 211B of the 2 nd rotor core 21B is 40 °, and 1 width of the 2 nd concave portion 212B is 80 °. As shown in fig. 19C, the 3 rd convex portion 213C formed in the 3 rd through hole 211C of the 3 rd rotor core portion 21C has a width of 1 of 40 °, and the 3 rd concave portion 212C has a width of 1 of 80 °.

The shaft 30 is press-fitted so that the circumferential positions of the 1 st convex portion 213a, the 2 nd concave portion 212b, and the 3 rd concave portion 212c, the circumferential positions of the 2 nd convex portion 213b, the 1 st concave portion 212a, and the 3 rd concave portion 212c, and the circumferential positions of the 3 rd convex portion 213c, the 1 st concave portion 212a, and the 2 nd concave portion 212b are aligned with each other.

That is, in a circumferential range where the circumferential range of the 1 st convex portion 213a and the circumferential ranges of the 2 nd concave portion 212b and the 3 rd concave portion 212c overlap when viewed from the axial end portion of the shaft, the surface of the shaft 30 including the contact surface of the shaft 30 with the 1 st convex portion 213a only contacts the 1 st convex portion 213 a. In a circumferential range where a circumferential range of the 2 nd convex portion 213b and circumferential ranges of the 3 rd concave portion 212c and the 1 st concave portion 212a overlap when viewed from an axial end portion of the shaft 30, only the 2 nd convex portion 213b is in contact with a surface of the shaft 30 including a contact surface of the shaft 30 in contact with the 2 nd convex portion 213 b. In a circumferential range where a circumferential range of the 3 rd convex portion 213c and circumferential ranges of the 1 st concave portion 212a and the 2 nd concave portion 212b overlap when viewed from the axial end portion of the shaft 30, only the 3 rd convex portion 213c is in contact with a surface of the shaft 30 including a contact surface of the shaft 30 with which the 3 rd convex portion 213c is in contact.

As described above, in the rotating electric machine 100 according to embodiment 5, even with the rotor core that is long in the axial direction, the surface of the shaft 30 that contacts the rotor core 21 differs in the axial direction when the shaft 30 is press-fitted, so that the occurrence of seizure can be reduced on the outer peripheral surface of the shaft 30, and buckling of the shaft 30 can be suppressed.

In embodiments 1 to 5, the example in which the 1 st, 2 nd, and 3 rd rotor cores 21a, 21b, and 21c have the 1 st, 2 nd, and 3 rd positioning holes 214a, 214b, and 214c that penetrate in the in-plane axial direction is shown, but the 1 st, 2 nd, and 3 rd positioning portions for determining the circumferential position may be provided, and the 1 st, 2 nd, and 3 rd positioning portions may be grooves that are provided on the outer circumferential surfaces of the 1 st, 2 nd, and 3 rd rotor cores 21a, 21b, and 21c by, for example, cutting.

In embodiments 1 to 5, the 1 st rotor core 21a, the 2 nd rotor core 21b, and the 3 rd rotor core 21c are disposed in close contact with each other, but a step skew structure having a gap for reducing the cogging torque may be employed.

In embodiments 1 to 5, the rotor core 21 has a substantially polygonal prism shape, but may have a substantially cylindrical shape. The generally polygonal prism shape is herein a cylinder comprising polygonal corners with rounded corners. The substantially cylindrical shape includes an elliptical cylinder as well as a perfect cylinder in a cross-sectional shape of a plane perpendicular to the axial direction.

In embodiments 1 to 5, the rotating electric machine 100 of the Surface Magnet type (SPM) structure is described, but the present invention can also be applied to a rotating electric machine 100 of the embedded Magnet type (IPM) structure.

In embodiments 1 to 5, an example is shown in which a plurality of magnets 22 in which N poles and S poles are alternately magnetized in the circumferential direction are used, but a ring-shaped magnet 22 in which N poles and S poles are alternately magnetized in the circumferential direction may be used.

In embodiments 1 to 5, the rotating electrical machine 100 is an electric motor, but may be a generator.

While various exemplary embodiments and examples have been described in the present invention, the various features, modes and functions described in 1 or more embodiments are not limited to the application to the specific embodiments, and may be applied to the embodiments alone or in various combinations.

Therefore, numerous modifications not illustrated can be conceived within the technical scope disclosed in the present specification. For example, the case where at least 1 component is modified, added, or omitted, and the case where at least 1 component is extracted and combined with the components in the other embodiments are included.

Description of the reference numerals

100: rotating electrical machine, 10: stator, 20: rotor, 30: shaft, 21: rotor core, 21 a: 1 st rotor core, 21 b: 2 nd rotor core, 21 c: 3 rd rotor core, 211 a: 1 st through hole, 211 b: 2 nd through hole, 211 c: 3 rd through hole, 212 a: 1 st recess, 212 b: 2 nd recess, 212 c: 3 rd recess, 213 a: 1 st projection, 213 b: 2 nd convex portion, 213 c: 3 rd convex portion, 214 a: 1 st positioning hole, 214 b: positioning hole 2, 214 c: and (3) a positioning hole.

Claims (16)

1. A rotating electric machine is characterized by comprising:

a shaft;

a rotor including a 1 st rotor core portion and a 2 nd rotor core portion, the 1 st rotor core portion being formed by continuously laminating a plurality of 1 st core pieces in an axial direction of the shaft, an inner peripheral surface of a 1 st through hole of the shaft being press-fitted into a radial center portion of the 1 st core piece, a 1 st convex portion being in contact with the shaft and a 1 st concave portion being not in contact with the shaft being alternately formed in a circumferential direction, the 2 nd rotor core portion being formed by continuously laminating a plurality of 2 nd core pieces in the axial direction of the shaft, an inner peripheral surface of a 2 nd through hole of the shaft being press-fitted into a radial center portion of the 2 nd core piece, a 2 nd convex portion being in contact with the shaft and a 2 nd concave portion being not in contact with the shaft being alternately formed in the circumferential direction, circumferential positions of the 1 st concave portion and the 2 nd convex portion and circumferential positions of the 1 st convex portion and the 2 nd concave portion being aligned with each other, and the 1 st rotor core portion and the 2 nd rotor core portion being arranged in the axial direction, magnets are arranged along the circumferential direction of the 1 st rotor core part and the 2 nd rotor core part; and

and a stator disposed to face a radially outer side of the rotor.

2. The rotating electric machine according to claim 1,

in a circumferential range where a circumferential range of the 2 nd convex portion and a circumferential range of the 1 st concave portion overlap as viewed from an axial end portion of the shaft, a surface of the shaft including a contact surface of the shaft with the 2 nd convex portion is in contact with only the 2 nd convex portion,

in a circumferential range where a circumferential range of the 1 st convex portion and a circumferential range of the 2 nd concave portion overlap as viewed from the axial end portion, only the 1 st convex portion is in contact with a surface of the shaft including a contact surface of the shaft in contact with the 1 st convex portion.

3. The rotating electric machine according to claim 1 or 2,

the 1 st recessed part and the 1 st raised part are formed at equal intervals in the circumferential direction, and the 2 nd recessed part and the 2 nd raised part are formed at equal intervals in the circumferential direction.

4. The rotating electric machine according to any one of claims 1 to 3,

the 1 st recessed part and the 2 nd raised part have the same width and the same number, and the 1 st raised part and the 2 nd recessed part have the same width and the same number.

5. The rotating electric machine according to any one of claims 1 to 4,

the 1 st rotor core portion has a 1 st positioning portion that positions circumferential positions of the 1 st recessed portion and the 1 st projecting portion, the 2 nd rotor core portion has a 2 nd positioning portion that positions circumferential positions of the 2 nd recessed portion and the 2 nd projecting portion, and the 1 st rotor core portion and the 2 nd rotor core portion are arranged in an axial direction with circumferential positions of the 1 st positioning portion and the 2 nd positioning portion aligned.

6. The rotating electric machine according to claim 5,

the 1 st positioning portion and the 2 nd positioning portion are a 1 st positioning hole and a 2 nd positioning hole, respectively, which penetrate in the axial direction.

7. The rotating electric machine according to claim 6,

the 1 st recessed part and the 1 st projecting part are formed at equal intervals in the circumferential direction, respectively, the 1 st positioning hole is provided at a position facing the rotation center of the rotor, the 2 nd recessed part and the 2 nd projecting part of the 2 nd rotor core are formed at equal intervals in the circumferential direction, respectively, the 2 nd recessed part and the 2 nd projecting part of the 2 nd rotor core are provided at a position facing the rotation center, respectively, and the 1 st rotor core and the 2 nd rotor core are arranged at 180-degree rotational symmetry with respect to the rotation center.

8. The rotating electric machine according to claim 6 or 7,

the 1 st positioning hole and the 2 nd positioning hole have 2 holes having different shapes at positions facing each other with the rotation center of the rotor interposed therebetween.

9. The rotating electric machine according to claim 8,

the product of the radius of one of the 2 holes and the distance from the center of the one hole to the rotation center is equal to the product of the radius of the other hole and the distance from the center of the other hole to the rotation center.

10. The rotating electric machine according to any one of claims 1 to 9,

an inner peripheral surface of the 1 st through hole of the 1 st rotor core and an inner peripheral surface of the 2 nd through hole of the 2 nd rotor core have continuous curved surfaces, respectively.

11. A method for manufacturing a rotating electric machine, comprising the steps of:

a chip forming step of forming a 1 st through hole in the radial center portion of the 1 st chip by punching so that the 1 st concave portion and the 1 st convex portion are alternately provided in the circumferential direction on the inner circumferential surface, and forming a 2 nd through hole in the radial center portion of the 2 nd chip by punching so that the 2 nd concave portion and the 2 nd convex portion are alternately provided in the circumferential direction on the inner circumferential surface;

a rotor core forming step of forming a 1 st rotor core by stacking a plurality of the 1 st core pieces such that the 1 st concave portions and the 1 st convex portions are axially connected to each other, and forming a 2 nd rotor core by stacking a plurality of the 2 nd core pieces such that the 2 nd concave portions and the 2 nd convex portions are axially connected to each other;

a shaft press-fitting step of press-fitting a shaft into the 1 st through hole and the 2 nd through hole so that circumferential positions of the 1 st concave portion and the 2 nd convex portion and circumferential positions of the 1 st convex portion and the 2 nd concave portion are aligned with each other;

a magnet bonding step of bonding magnets in the circumferential direction of the 1 st rotor core portion and the 2 nd rotor core portion; and

and a stator assembling step of assembling a stator so as to face the radial outer sides of the 1 st and 2 nd rotor cores.

12. The manufacturing method of a rotating electric machine according to claim 11,

in the shaft press-fitting step, a 1 st positioning hole is formed in the 1 st chip, a 2 nd positioning hole is formed in the 2 nd chip, and a pin extending in the axial direction of a press-fitting fixing tool is inserted through the 1 st positioning hole and the 2 nd positioning hole to position the 1 st rotor core portion and the 2 nd rotor core portion, thereby press-fitting the shaft.

13. The manufacturing method of a rotating electric machine according to claim 12,

in the shaft press-fitting step, the 1 st rotor core portion is disposed in the press-fitting fixing tool, and after the shaft is press-fitted into the 1 st through hole of the 1 st rotor core portion, the 2 nd rotor core portion is disposed in the press-fitting fixing tool, and the shaft is press-fitted into the 2 nd through hole of the 2 nd rotor core portion.

14. The manufacturing method of a rotating electric machine according to claim 12,

in the shaft press-fitting step, the shaft is press-fitted into the 1 st through hole of the 1 st rotor core and the 2 nd through hole of the 2 nd rotor core at a time by arranging the 1 st rotor core and the 2 nd rotor core in line with each other and disposing the rotor cores on the pins of the press-fitting jig.

15. The manufacturing method of a rotating electrical machine according to any one of claims 11 to 14,

in the chip forming step, the 1 st convex portion, the 1 st concave portion, the 2 nd convex portion, and the 2 nd concave portion are formed so that the 1 st chip is turned over to be the 2 nd chip.

16. The manufacturing method of a rotating electrical machine according to any one of claims 11 to 14,

in the chip forming step, the 1 st convex portion, the 1 st concave portion, the 2 nd convex portion, and the 2 nd concave portion are formed so as to form the 2 nd chip by rotating the 1 st chip by 180 degrees.

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