JPH0578158U - Rotating electric machine rotor - Google Patents

Abstract

(57) [Abstract] [Purpose] The rotary shaft and core can be press-fitted and fixed with a small force input, and the fixing force in the rotational direction of the rotary shaft and core is large.
Provided is a rotor of a rotary electric machine, which can press-fit and fix a rotary shaft and a core with high accuracy even if the surface roughness and roundness of the outer circumference of the rotary shaft and the inner circumference of the hole of the core are rough. [Structure] An outer peripheral surface of a rotating shaft 11 and a core 12 facing the outer peripheral surface.
A gap 15 is provided between the inner peripheral surface of the hole of the core 12 and the flat surface portion 13 parallel to the axis on the outer peripheral surface of the rotary shaft 11. The protrusion 14 is provided on the. The core 12 is press-fitted and fixed to the rotating shaft 11 by bringing the tip end of the protrusion 14 into contact with the flat surface portion 13.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotor of a rotary electric machine, and more particularly, to a press-fitting and fixing structure of a rotary shaft and a core thereof.

[0002]

[Prior Art]

 BACKGROUND ART As a conventional example of a rotor of a rotating electric machine, there is one that includes a rotary shaft and a core that is press-fitted and fixed around the rotary shaft. A drive magnet is attached to the core, or a drive coil is wound around the core. As an example of the structure in which the core is press-fitted and fixed to the rotary shaft, a flat portion is formed on a part of the outer peripheral surface of the cylindrical rotary shaft to make the cross-sectional shape of the rotary shaft into a D-shape. There is one in which a hole having a shape corresponding to the cross-sectional shape is provided in the core, and the D-shape of the hole of the core and the D-shape of the rotating shaft are matched to press-fit both. As another example, as shown in FIG. 9, a plurality of bent portions 33 are formed along the inner peripheral edge of the ring-shaped core 32 in one axial direction and are inserted into the inner diameter portion of the core 32. There is also one in which the core 32 and the rotary shaft 31 are integrally fixed by pressing the rotary shaft 31 toward the center by the plurality of bent portions 33. Japanese Utility Model Application Laid-Open No. 2-94442 discloses a plate for holding a magnet and fixing it to a rotary shaft by fixing the plate to the rotary shaft with a structure similar to the latter structure.

[0003]

[Problems to be solved by the device]

 According to the former structure of the conventional fixing structure of the rotating shaft and the core, if there is a slight gap between the outer peripheral surface of the rotating shaft and the hole of the core, rattling occurs between the rotating shaft and the core. Therefore, it is necessary to fix the gap by filling it with an adhesive. On the other hand, if the outer peripheral surface of the rotating shaft and the hole in the core are tightly fitted so that rattling does not occur, the force required for press-fitting increases and workability deteriorates. The drawback is that the holes must be formed with high precision. Also, with the latter fixing structure, since the bent portion of the core is merely pressed against the outer peripheral surface of the rotating shaft, there is the drawback that the fixing force in the rotational direction between the rotating shaft and the core is weak, and the bent portion There is also a drawback in that the press-fitting direction of the rotary shaft is limited to one direction depending on the bending direction of.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The rotating shaft and the core can be press-fitted and fixed with a small press force, and the rotating direction of the rotating shaft and the core can be fixed. The rotating machine rotor that can press-fit and fix the rotating shaft and the core with high accuracy even if the accuracy of the surface roughness and roundness of the outer circumference of the rotating shaft and the inner circumference of the core hole is rough. The purpose is to provide.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a gap between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the hole of the core facing the rotating shaft, and the outer peripheral surface of the rotating shaft has a flat portion parallel to the axis. A protrusion is provided on the inner circumference of the hole of the core so that the tip contacts the flat portion.

[0006]

[Action]

 The rotating shaft and the core are press-fitted with the flat portion of the rotating shaft and the tip of the protrusion provided on the inner circumference of the hole of the core in contact with each other. There is a gap between the outer peripheral surface and the inner peripheral surface of the core hole. The rotating force is transmitted between the rotating shaft and the core by the contact between the flat surface portion and the tip of the protrusion.

[0007]

【Example】

 An embodiment of an armature of a rotating electric machine according to the present invention will be described below with reference to the drawings. First, an outline of an embodiment of the present invention will be described. In FIG. 2, a rotor 20 of a rotating electric machine includes a rotary shaft 11 and a core 12 press-fitted and fixed around the rotary shaft 11, and a cylindrical magnet 18 is fixedly fitted around the outer periphery of the core 12. Has been. The core 12 is configured by laminating a plurality of core plates, but may be a single core that is integrally molded. The rotating shaft 11 is rotatably supported by a bearing provided on the motor case. The magnets 18 are magnetized with different poles alternately at regular intervals in the circumferential direction, and their outer peripheral surfaces face the stator with a proper gap.

As shown in FIG. 5, the rotary shaft 11 is provided with a flat surface portion 13 on the outer peripheral surface in parallel with the axis. A plurality of plane portions 13 (three in the illustrated example) are provided at equal intervals in the circumferential direction of the shaft 11.

The core 12 is provided with a protrusion 14 on the inner peripheral side of its center hole as shown in FIG. The protrusions 14 are provided at three locations in the circumferential direction as a set of two pieces arranged in the circumferential direction. Each pair of protrusions 14 is provided so as to correspond to each flat surface portion 13 of the rotating shaft 11, and when the rotating shaft 11 is inserted into the central hole of the core 12, the tip of each protrusion 14 rotates as described above. It is adapted to come into contact with each flat surface portion 13 of the shaft 11. The diameter of the central hole of the core 12 is larger than the outer diameter of the rotating shaft 11, and when the rotating shaft 11 is inserted into the central hole of the core 12, the outer peripheral surface of the rotating shaft 11 and the inner periphery of the hole of the core 12 facing the outer peripheral surface of the rotating shaft 11. There is a gap between the surface and the surface.

FIGS. 1 and 3 show a state in which the center hole of the core 12 is inserted into the rotary shaft 11 and the rotary shaft 11 and the core 12 are press-fitted and fixed. In FIG. 1 and FIG. 3, the respective plane portions 13 of the rotary shaft 11 and the positions of the two protrusions 14 of the core 12 in the circumferential direction are aligned, and the central hole of the core 12 is aligned with the rotary shaft 11. When inserted, the rotary shaft 11 and the core 12 are press-fitted and fixed in a state where the tips of the protrusions 14 are in contact with the flat surface portion 13. The protrusion length of each of the protrusions 14 is set so that each protrusion 14 comes into contact with each of the planar portions 13 with an appropriate pressure. Since the diameter of the central hole of the core 12 is larger than the outer diameter of the rotating shaft 11, when the core 12 is press-fitted into the rotating shaft 11, the outer peripheral surface of the rotating shaft 11 and the inner peripheral surface of the hole of the core 12 facing the outer peripheral surface of the rotating shaft 11 are different from each other. Between them, an arc-shaped gap 15 is formed except the above-mentioned protrusions 14.

As shown in detail in FIG. 1, between the pair of protrusions 14, 14, a protrusion 19 having a shorter protrusion length than the protrusions 14, 14 is provided. A gap 16 is provided between the flat portion 13 and the flat portion 13. As described above, the rotating shaft 11 and the core 12 are press-fitted and fixed by bringing the tips of the protrusions 14 into contact with the flat surface portion 13, and a necessary and sufficient fixing force is obtained. In order to more firmly fix the above, it is sufficient to infiltrate the gap 16 with an adhesive and harden it.

According to the embodiment described above, the flat portion 13 parallel to the axis is provided on the outer peripheral surface of the rotary shaft 11, and the projection 14 is formed on the inner circumference of the hole of the core 12 so that the tip of the flat portion 13 contacts the flat portion 13. Since the rotating shaft 11 and the core 12 are press-fitted, it is sufficient to press-fit the rotating shaft 11 and the core 12 with a force that can oppose the force with which the tip of the protrusion 14 abuts against the flat surface portion 13. Compared with the conventional press-fitting structure in which the 12 holes are press-fitted in contact with each other over substantially the entire circumference, there is an advantage that an extremely small press-fitting force is sufficient. Further, since the projection 14 is brought into contact with the flat surface portion 13 described above, the fixing force in the rotational direction of the rotating shaft 11 and the core 12 is large, and the rotating shaft 11 and the core 12 move relative to each other in the rotating direction. It doesn't move. In particular, in the illustrated embodiment, the two protrusions 14 are arranged in the circumferential direction in the circumferential direction, and therefore, the two protrusions 14 receive the force in the rotational direction, so that the rotation shaft 11 and the core 12 are separated from each other. The fixing force in the direction of rotation is further increased.

According to the above-described embodiment, the inner peripheral surface of the hole of the core 12 with respect to the flat surface portion 13 of the rotary shaft 11 is disposed between the outer peripheral surface of the rotary shaft 11 and the inner peripheral surface of the hole of the core 12 facing the outer peripheral surface. Since the gap 15 is provided except for the contacting portion with the protrusion 14 provided on the surface of the rotating shaft 11, the surface roughness of the rotating shaft 11 and the rotating shaft 11 and the core 12 can be maintained as long as the accuracy of the flat surface portion 13 and the protrusion 14 is maintained. Even if the accuracy or roundness of the diameter of the central hole is rough, there is no problem and the cost can be reduced from the aspect of processing the parts.

Further, when a plurality of core plates are laminated to form the core 12, according to the above-described embodiment, the protrusions 14 are provided at equal intervals in the circumferential direction of the core 12, so that the individual core plates are separated from each other. The core 12 having a predetermined shape can be formed by stacking the cores 12 while shifting them by a constant angle in the circumferential direction. The core plate is made by punching a core material obtained by rolling a core raw material, and the ease of passing the magnetic flux differs depending on the rolling direction, but as described above, while shifting each core plate by a certain angle in the circumferential direction. There is an advantage that the ease of passing the magnetic flux can be made uniform by stacking them.

Next, various modified examples will be described. The embodiment shown in FIG. 6 eliminates the projection 19 having a step difference between the pair of projections 14 and 14 in the above-described embodiment, and eliminates a flat surface between the projections 14 and 14. A relatively large gap 22 facing the portion 13 is provided. Even with such a configuration, the same operational effects as those of the above-described embodiment can be obtained.

In the embodiments described so far, two protrusions on the inner circumference of the core are provided as a set, but as in the embodiment shown in FIG. 7, one protrusion is provided at one place. The protrusion 23 may be used. Even in this case, if one set of the projections 23 is provided at a plurality of places, the same effect as that of the above-described embodiments can be obtained. Further, even when a set of protrusions 23 is provided at one place, if the protrusions 23 have a certain extent of expansion, the same effect as that of the above-described embodiments can be obtained.

In the embodiment shown in FIG. 8, a flat portion 13 is provided at one location in the circumferential direction of the rotary shaft 11, and a projection 14 is provided at one location on the inner circumference of the core 12 corresponding to this one flat portion 13. It was provided. The two protrusions 14 provided at one place are formed as a set. When the core 12 is inserted into the rotary shaft 11 by aligning the positions of the flat surface portion 13 and the projection 14, the tip of the projection 14 contacts the flat surface portion 13, and the peripheral surface of the rotary shaft 11 on the opposite side of the flat surface portion 13 is in contact. Comes into line contact with the inner peripheral surface of the core 12. In FIG. 8, reference numeral 25 indicates this line contact type contact portion. Also in the case of this embodiment, a gap 15 is provided between the outer peripheral surface of the rotating shaft 11 and the inner peripheral surface of the core 12 except for the contact portion between the flat surface portion 13 and the protrusion 14 and the contact portion 25. Has been. In the case of this embodiment as well, the same operational effects as those of the previous embodiments can be obtained.

The core may have a drive magnet as in the example shown in FIG. 2, or may have a salient pole and a coil may be wound around this salient pole.

[0019]

[Effect of the device]

 According to the present invention, the outer peripheral surface of the rotary shaft is provided with a flat portion parallel to the axis, and the projection is provided on the inner periphery of the core hole so that the tip contacts the flat portion, so that the rotary shaft and the core are press-fitted. In this case, it suffices to press-fit with a force that can oppose the force with which the tip of the protrusion abuts against the flat surface portion, and with the conventional press-fitting with the rotating shaft and the hole of the core in contact with each other over almost the entire circumference. Compared to the press-fitting structure, it has the advantage that an extremely small press-in force is sufficient. Further, since the projection is brought into contact with the flat surface portion, the fixing force in the rotating direction of the rotating shaft and the core is large, and the rotating shaft and the core do not move relative to each other in the rotating direction. Furthermore, since a gap is provided between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the core hole facing the rotating shaft, except for the contact portion of the core protrusion with the rotating shaft flat surface, As long as the accuracy of the parts and protrusions is maintained, the surface roughness of the rotating shaft, the accuracy of the diameter of the center hole of the rotating shaft and the core, or the roundness can be rough, reducing the cost from the part processing surface. Can be planned.

[Brief description of drawings]

FIG. 1 is a partial sectional front view showing a main part of an embodiment of a rotor of a rotary electric machine according to the present invention.

FIG. 2 is a partial cross-sectional side view showing the outline of the embodiment.

FIG. 3 is a partially sectional front view of the above embodiment.

FIG. 4 is a front view of the core in the above embodiment.

FIG. 5 is a cross-sectional front view of the rotary shaft in the above embodiment.

FIG. 6 is a partial cross-sectional front view showing the main part of another embodiment of the rotor of the rotary electric machine according to the present invention.

FIG. 7 is a partial cross-sectional front view showing a main part of still another embodiment of the rotor of the rotating electric machine according to the present invention.

FIG. 8 is a partially sectional front view showing still another embodiment of the rotor of the rotary electric machine according to the present invention.

FIG. 9 is a side view schematically showing an example of a rotor of a conventional rotating electric machine.

[Explanation of symbols]

 11 rotating shaft 12 core 13 plane part 14 protrusion 15 gap

Claims (1)

[Scope of utility model registration request] 1. A rotor of a rotating electric machine comprising a rotary shaft and a core press-fitted and fixed around the rotary shaft, wherein an outer peripheral surface of the rotary shaft and an inner peripheral surface of a hole of the core facing the outer peripheral surface of the rotary shaft. And a flat portion parallel to the axis is provided on the outer peripheral surface of the rotary shaft, and a projection is provided on the inner circumference of the hole of the core so that the tip contacts the flat portion. The rotor of a rotating electric machine.