JP2021129407A - Rotor of electric motor, and electric motor with rotor - Google Patents

Abstract

To provide a rotor of an electric motor and an electric motor with the rotor, which have a technique for resolving the problem of a foreign matter existing outside the electric motor from entering inside of the electric motor in the conventional art.SOLUTION: A rotor 14 of an electric motor includes a rotating shaft 26 extending in an axial direction, and a foreign matter receiving hole 50 that is formed in a rotating shaft 26 so as to face and open a gap 44 between an end 22 in an axial direction of a stator of the electric motor and the rotor 14 and receives a foreign matter entering the inside of the electric motor through the gap 44. According to the present disclosure, since the foreign matter passing through the gap 44 can be received by the foreign matter receiving hole 50, it is possible to reliably prevent the foreign matter from entering the inside of the electric motor.SELECTED DRAWING: Figure 2

Description

The present invention relates to a rotor of a motor and an electric motor including the rotor.

A structure is known in which foreign matter inside the motor is discharged to the outside (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 09-322465

Conventionally, there has been a demand for a technique for preventing foreign matter existing outside the motor from entering the inside of the motor.

In one aspect of the present disclosure, the rotor of the motor is formed in the rotary shaft so as to open so as to face the gap between the rotary shaft extending in the axial direction and the axial end of the stator of the motor and the rotor, and the gap is formed. It is provided with a foreign matter receiving hole that receives foreign matter that passes through and enters the inside of the motor.

According to the present disclosure, foreign matter outside the motor is attracted to the foreign matter receiving hole that opens facing the gap between the axial end of the theta and the rotor. As a result, the foreign matter can be received in the foreign matter receiving hole, so that the foreign matter can be reliably prevented from entering the inside of the motor.

It is sectional drawing of the electric motor which concerns on one Embodiment. It is a cross-sectional enlarged view which enlarged the main part of the cross-sectional view shown in FIG. FIG. 2 is a cross-sectional perspective view of the motor shown in FIG. It is sectional drawing of the electric motor which concerns on other embodiment. It is a cross-sectional enlarged view of the electric motor which concerns on still another embodiment. It is a cross-sectional enlarged view of the electric motor which concerns on still another embodiment. It is a cross-sectional enlarged view of the electric motor which concerns on still another embodiment. It is a cross-sectional enlarged view of the electric motor which concerns on still another embodiment. It is a cross-sectional enlarged view of the electric motor which concerns on still another embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In various embodiments described below, similar elements are designated by the same reference numerals, and duplicate description will be omitted. Further, in the following description, the axial direction indicates a direction along the rotation axis A of the rotor 14 described later, the radial direction indicates the radial direction of the circle centered on the axis A, and the circumferential direction is the circumferential direction. Indicates the circumferential direction of the circle. Further, for convenience, the direction indicated by the arrow B in the drawing is referred to as the downward direction in the axial direction (first direction).

The electric motor 10 according to the embodiment will be described with reference to FIG. The electric motor 10 rotates, for example, drives the spindle of a machine tool, and includes a stator 12 and a rotor 14 rotatably arranged inside the stator 12 in the radial direction. The stator 12 includes a stator core 16, stator housings 18 and 20, and a labyrinth forming wall 22.

The stator core 16 is composed of, for example, a plurality of magnetic steel plates laminated in the axial direction. A plurality of tooth portions 16a arranged in the circumferential direction are formed at the radial inner end portion of the stator core 16, and the coil 24 is wound around the tooth portions 16a. The stator housing 18 is fixed to the lower side in the axial direction of the stator core 16, while the stator housing 20 is fixed to the upper side in the axial direction of the stator core 16.

The labyrinth forming wall 22 has an annular shape and is fixed to the end surface 18a on the lower side in the axial direction of the stator housing 18. The labyrinth forming wall 22 defines an axially lower end of the stator 12. More specifically, the labyrinth-forming wall 22 has a first wall portion 36, a second wall portion 38, a third wall portion 40, and a fourth wall portion 42 formed integrally with each other.

The first wall portion 36 extends axially downward from the end surface 18a of the stator housing 18. The second wall portion 38 extends radially inward from the axial lower end of the first wall portion 36. The third wall portion 40 extends axially upward from the radial inner end of the second wall portion 38. The fourth wall portion 42 extends radially inward from the axial upper end of the third wall portion 40.

The rotor 14 has a rotating shaft 26, a rotor core 28, and a flange portion 30. The rotating shaft 26 is a columnar member that extends straight in the axial direction. The rotor core 28 is fixed to the outside in the radial direction of the rotating shaft 26, and a plurality of magnets (not shown) are arranged inside the rotor core 28. The flange portion 30 is fixed to the outer peripheral surface 26a so as to project outward in the radial direction from the outer peripheral surface 26a of the rotating shaft 26, and rotates integrally with the rotating shaft 26. In the present embodiment, the flange portion 30 has an annular shape.

An external device such as a spindle is connected to the lower end of the rotating shaft 26 in the axial direction via a coupling. The electric motor 10 outputs a rotational force to the external device by rotating the rotor 14. That is, the lower side of the rotating shaft 26 in the axial direction is the output side of the motor 10. In the present embodiment, the rotary shaft 26 is positioned so that the lower axial direction (that is, the output side) of the rotary shaft 26 coincides with the lower gravity direction.

A bearing 32 is inserted between the stator housing 18 and the rotating shaft 26, and a bearing 34 is inserted between the stator housing 20 and the rotating shaft 26. These bearings 32 and 34 rotatably support the rotor 14 to the stator housings 18 and 20.

Next, the configuration of the electric motor 10 will be described in more detail with reference to FIGS. 2 and 3. A gap 44 is formed between the labyrinth forming wall 22 and the flange portion 30. More specifically, the gap 44 has a first gap 44a and a second gap 44b. The first gap 44a is defined between the third wall portion 40 of the labyrinth forming wall 22 and the outer peripheral surface 30a of the flange portion 30 so as to extend in the axial direction, and extends to the outside of the motor 10 at the lower end in the axial direction. It is open. The second gap 44b is defined between the fourth wall portion 42 of the labyrinth forming wall 22 and the axially upper end surface 30b of the flange portion 30 so as to extend in the radial direction, and is defined with the first gap 44a. Communicating.

By such a labyrinth forming wall 22 and the flange portion 30, a gap 44 (so-called labyrinth) of a complicated path extending in different directions is formed, and a foreign substance (for example, oil, cutting fluid, etc.) existing outside the motor 10 is formed. The liquid material) is prevented from entering the inside of the electric motor 10. However, a part of such foreign matter may pass through the gap 44 and enter the inside of the motor 10.

Therefore, in the present embodiment, the rotor 14 has a foreign matter receiving hole 50 for receiving the foreign matter entering the inside of the electric motor 10 through the gap 44. The foreign matter receiving hole 50 is formed in the rotating shaft 26 so as to open facing the gap 44. More specifically, the foreign matter receiving hole 50 has a main hole 52 and a plurality of communication holes 54.

The main hole 52 is formed in the central portion of the rotating shaft 26 so as to be concentric with the rotating shaft 26, and is opened downward in the axial direction at the end surface 26b on the lower side in the axial direction of the rotating shaft 26. In the present embodiment, the inner peripheral surface 56 that defines the main hole 52 is an inclined surface that is inclined with respect to the axial direction so as to expand outward in the radial direction as it goes downward in the axial direction.

The communication hole 54 opens facing the gap 44 so that the gap 44 and the main hole 52 communicate with each other. In the present embodiment, the plurality of communication holes 54 are arranged so as to be arranged at substantially equal intervals in the circumferential direction. Each communication hole 54 has a first hole 58 and a second hole 60. The first hole 58 has an opening 62 that opens facing the second gap 44b, and extends radially inward from the opening 62.

In the present embodiment, the first hole portion 58 extends so as to be inclined in the radial direction so as to be axially downward as it goes inward in the radial direction. Here, in the first hole 58, the projected region when the opening 62 is projected outward in the radial direction overlaps with the region of the second gap 44b (for example, the entire projection region is the second gap). It is arranged facing the second gap 44b so as to be included in the region of 44b).

Alternatively, the first hole portion 58 is arranged so as to face the second gap 44b so that its central axis passes through the region of the second gap 44b. The opening 62 is arranged at an axial position between the bearing 32 (more specifically, the tip 42a of the fourth wall portion 42) and the flange portion 30.

Further, the outer peripheral surface 26a of the rotary shaft 26 is formed with an annular groove 64 that is recessed inward from the outer peripheral surface 26a. The annular groove 64 is formed so as to extend in the circumferential direction over the entire circumference of the outer peripheral surface 26a. The opening 62 of the first hole 58 is opened at the bottom surface of the annular groove 64, and the first hole 58 extends from the annular groove 64.

The second hole portion 60 is connected to the first hole portion 58 at the upper end portion in the axial direction thereof, extends downward in the axial direction from the first hole portion 58, and is connected to the main hole 52 to define the main hole portion 52. The end face 66 on the upper side in the axial direction opens toward the main hole 52. The extending direction of the second hole portion 60 is substantially parallel to the axial direction.

In the present embodiment, the main hole 52 is arranged at a position axially downwardly separated from the opening 62 of the first hole 58, whereby the main hole 52 is axially downwardly separated from the opening 62 (that is, that is). , The side facing the outside of the electric motor 10 when viewed from the opening 62). Further, the opening at the lower end of the main hole 52 in the axial direction is closed by a plug 68 detachably inserted into the opening.

Next, the function of the foreign matter receiving hole 50 will be described. Assuming that the foreign matter moves through the second gap 44b toward the inside of the motor 10, the foreign matter moves from the opening 62 that opens facing the second gap 44b to the foreign matter receiving hole 50 (specifically, the first foreign matter). You are invited to the hole 58) of 1. In this way, since the foreign matter can be received by the foreign matter receiving hole 50, it is possible to reliably prevent the foreign matter from entering the inside of the motor 10 beyond the second gap 44b.

Further, in the present embodiment, the foreign matter receiving hole 50 has a main hole 52 and a communication hole 54. According to this configuration, foreign matter that has entered the communication hole 54 (specifically, the first hole 58) from the opening 62 is guided to the main hole 52 through the communication hole 54 and stored in the main hole 52. Can be done. By guiding the rotor 14 to the main hole 52 in this way, it is possible to prevent foreign matter that has entered the foreign matter receiving hole 50 from leaking from the foreign matter receiving hole 50 when the rotor 14 is rotated.

Further, in the present embodiment, an annular groove 64 is formed on the outer peripheral surface 26a of the rotating shaft 26. According to this configuration, the foreign matter that has passed through the second gap 44b can be guided to the opening 62 along the annular groove 64, so that the foreign matter can be effectively guided from the opening 62 into the foreign matter receiving hole 50. Can be introduced.

Further, in the present embodiment, the electric motor 10 is positioned so that the lower side in the axial direction (that is, the output side) of the rotor 14 coincides with the lower side in the direction of gravity, and the main hole 52 is more shaft than the opening 62 of the communication hole 54. It extends downward in the direction (more specifically, it is arranged at a position separated axially downward from the opening 62).

Here, the foreign matter that has passed through the gap 44 will collect in the outlet region C (FIG. 2) of the second gap 44b. In this case, when the operation of the electric motor 10 is stopped, the foreign matter accumulated in the outlet region C is introduced into the main hole 52 located on the lower side in the gravity direction from the opening 62 through the communication hole 54 by the action of gravity. It will be stored in the main hole 52. Therefore, even if the electric motor 10 is restarted, it is possible to prevent foreign matter from leaking from the foreign matter receiving hole 50.

Further, in the present embodiment, the first hole portion 58 extends in an inclined direction in the radial direction so as to go downward in the axial direction (that is, downward in the gravity direction) as it goes inward in the radial direction. According to this configuration, the foreign matter accumulated in the outlet region C can be more effectively introduced into the main hole 52.

Further, in the present embodiment, the inner peripheral surface 56 defining the main hole 52 is an inclined surface that is inclined with respect to the axial direction so as to expand outward in the radial direction toward the downward direction in the axial direction (that is, the downward direction in the gravity direction). Is. Here, when the electric motor 10 is operated with the foreign matter stored in the main hole 52, the foreign matter is pressed against the inner peripheral surface 56 by the centrifugal force. In this case, since the inner peripheral surface 56 is an inclined surface, a force component that pushes the foreign matter downward in the axial direction is applied to the foreign matter from the inner peripheral surface 56, so that the foreign matter enters the main hole 52 when the motor 10 is operated. It can be more reliably prevented from leaking from.

Further, in the present embodiment, the opening at the lower end of the main hole 52 in the axial direction is closed by a removable plug 68. According to this configuration, the operator can remove the foreign matter accumulated in the main hole 52 by removing the coupling or the like from the rotating shaft 26, disassembling it, and removing the plug 68. This makes it possible to facilitate maintenance such as cleaning of the main hole 52.

Next, the rotor 70 according to another embodiment will be described with reference to FIG. The rotor 70 can be applied to the motor 10 instead of the rotor 14 described above. The rotor 70 according to this embodiment is different from the rotor 14 described above in the following configuration. That is, the rotor 70 includes a foreign matter receiving hole 72 and a second flange portion 80.

The foreign matter receiving hole 72 has a main hole 52 and a communication hole 74, and the communication hole 74 has a first hole portion 76 and a plurality of second hole portions 60, and has a gap 44 with the main hole 52. Communicate with. The first hole portion 76 is an annular hole extending in the circumferential direction so as to surround the axis A. Specifically, the first hole 76 has an annular opening 78 and extends radially inward from the opening 78.

The opening 78 opens on the outer peripheral surface 26a of the rotating shaft 26 so as to face the second gap 44b. The first hole portion 76 is inclined with respect to the radial direction so as to go downward in the axial direction as it goes inward in the radial direction. The second hole portions 60 are arranged at substantially equal intervals in the circumferential direction, and each extends axially between the first hole portion 76 and the main hole 52.

The second flange portion 80 is fixed to the outer peripheral surface 26a so as to project outward in the radial direction from the outer peripheral surface 26a of the rotating shaft 26, and rotates integrally with the rotating shaft 26. The second flange portion 80 is arranged so as to face each other adjacent to the upper side in the axial direction of the flange portion 30, and a fourth wall portion 42 of the labyrinth forming wall 22 is provided between the flange portion 30 and the second flange portion 80. Have been placed.

According to the present embodiment, since the first hole portion 76 is an annular hole, foreign matter accumulated in the outlet region C (FIG. 2) can be easily introduced into the first hole portion 76. Further, the second flange portion 80 can more effectively prevent foreign matter from entering the inside of the electric motor 10, and can easily introduce the foreign matter into the first hole portion 76. The second flange portion 80 may be applied to the rotor 14 described above.

Next, with reference to FIG. 5, another rotor 90 according to the embodiment will be described. The rotor 90 can be applied to the motor 10 instead of the rotor 14 described above. The rotor 90 according to this embodiment is different from the rotor 70 described above in the foreign matter receiving hole 82. Specifically, the foreign matter receiving hole 82 has a main hole 84 and a plurality of communication holes 86.

The communication holes 86 are arranged at substantially equal intervals in the circumferential direction, and each has openings 62. The opening 62 is opened at the bottom surface of the annular groove 64 so as to face the second gap 44b. Each communication hole 86 extends so as to incline downward in the axial direction as it goes inward in the radial direction, and is connected to the main hole 84 to communicate the main hole 84 and the gap 44.

The main hole 84 is formed in the central portion of the rotating shaft 26 so as to be concentric with the rotating shaft 26, and extends axially downward from the opening 62 of the communication hole 86. The main hole 84 is opened at the axially lower end surface 26b of the rotating shaft 26, and the opening of the main hole 84 is closed by the above-mentioned plug 68.

Further, the inner peripheral surface 88 that defines the main hole 84 is an inclined surface that is inclined with respect to the axial direction so as to expand outward in the radial direction as it goes downward in the axial direction, like the inner peripheral surface 56 described above. According to the present embodiment, foreign matter that has entered the communication hole 86 through the opening 62 can be guided to the main hole 84 by the action of gravity and stored in the main hole 84.

Next, with reference to FIG. 6, the rotor 100 according to another embodiment will be described. The rotor 100 can be applied to the motor 10 instead of the rotor 14 described above. The rotor 100 according to this embodiment is different from the rotor 70 shown in FIG. 4 in the foreign matter receiving hole 102. Specifically, the foreign matter receiving hole 102 has a main hole 104 and a communication hole 74.

The main hole 104 is arranged at a position separated axially downward from the opening 78 of the first hole portion 76, and the inner peripheral surface 106 defining the main hole 104 is a first inclined surface 108 and a step. It has a surface 110 and a second inclined surface 112. The first inclined surface 108 and the second inclined surface 112 are inclined in the axial direction so as to expand radially outward as they go downward in the axial direction (that is, downward in the gravity direction).

The stepped surface 110 is an annular plane substantially orthogonal to the axial direction, and extends between the first inclined surface 108 and the second inclined surface 112. The stepped surface 110 prevents foreign matter accumulated at the bottom of the main hole 104 from flowing backward in the axial direction along the second inclined surface 112 when the motor 10 is operating, so that the foreign matter leaks from the main hole 52. You can more surely prevent it from happening.

In the present embodiment, the case where the inner peripheral surface 106 has one step surface 110 and therefore expands outward in the radial direction in two steps toward the downward direction in the axial direction has been described. However, the inner peripheral surface 106 may be configured to expand outward in the radial direction in n steps by having n (n is a positive number of 2 or more) stepped surfaces 110.

Further, the main hole 104 (inner peripheral surface 106) according to the present embodiment may be applied to the rotor 14 or 90 described above. Further, instead of the stepped surface 110, the convex portion (or the inner peripheral surface 56, 88, 106) protruding inward in the radial direction from the inner peripheral surfaces 56, 88, 106 defining the main holes 52, 84, 104 is recessed. A groove) may be provided to prevent foreign matter from flowing back axially upward on the inner peripheral surfaces 56, 88, 106 by the convex portion (or groove).

Next, the rotor 120 according to still another embodiment will be described with reference to FIG. 7. The rotor 120 can be applied to the motor 10 instead of the rotor 14 described above. The rotor 120 according to this embodiment is different from the rotor 100 shown in FIG. 6 in the flange portion 122. The flange portion 122 is fixed to the outer peripheral surface 26a so as to project outward in the radial direction from the outer peripheral surface 26a of the rotating shaft 26, and rotates integrally with the rotating shaft 26.

In the present embodiment, the axial upper end surface 124 of the flange portion 122 is formed with an annular recess 126 that is recessed inward from the upper end surface 124. More specifically, the recess 126 extends from the upper end surface 124 downward in the axial direction to the cylindrical first surface 128 and from the axial lower end of the first surface 128 to the outer peripheral surface 26a of the rotating shaft 26. It is defined by a second surface 130 extending radially inward. Here, the second surface 130 is an inclined surface that is inclined with respect to the radial direction so as to go downward in the axial direction as it goes inward in the radial direction.

The recess 126 constitutes a part of the second gap 44b described above, and the opening 78 of the communication hole 74 faces the recess 126. According to the present embodiment, the foreign matter accumulated in the outlet region C is introduced into the communication hole 74 from the opening 78 through the second surface 130, and is guided to the main hole 104 through the communication hole 74. Therefore, the foreign matter accumulated in the outlet region C can be more effectively introduced into the main hole 104.

The recess 126 according to this embodiment may be applied to the rotor 14 or 90 described above. In this case, the opening 62 may be arranged so as to face the recess 126 formed on the axially upper end surface of the flange portion 30. The second surface 130 is not limited to the inclined surface as described above, and may be a plane orthogonal to the axial direction.

Next, the rotor 140 according to still another embodiment will be described with reference to FIG. In the present embodiment, the stator 12'has a labyrinth forming wall 22', and the labyrinth forming wall 22'is an annular flat plate member arranged so as to be substantially orthogonal to the axial direction, and is a stator housing. It is fixed to the end face 18a (FIG. 1) of 18. The labyrinth forming wall 22'defines the axially lower end of the stator 12'.

The rotor 140 is rotatably arranged inside the stator 12'in the radial direction and has a rotating shaft 26, a rotor core 28 (FIG. 1), a flange portion 142, and a foreign matter receiving hole 144. The flange portion 142 is fixed to the outer peripheral surface 26a so as to project outward in the radial direction from the outer peripheral surface 26a of the rotating shaft 26, and rotates integrally with the rotating shaft 26.

In the present embodiment, the flange portion 142 has an annular shape and is arranged adjacent to the upper side of the labyrinth forming wall 22'in the axial direction. More specifically, the flange portion 142 has a first wall portion 146, a second wall portion 148, and a third wall portion 150. The first wall portion 146 is fixed to the outer peripheral surface 26a of the rotating shaft 26 and projects radially outward from the outer peripheral surface 26a.

The second wall portion 148 extends axially downward from the radial outer end of the first wall portion 146. The third wall portion 150 extends radially inward from the axial lower end of the second wall portion 148. The reservoir hole 156 is defined by the first wall portion 146, the second wall portion 148, and the third wall portion 150.

A gap 154 is formed between the rotating shaft 26 and the flange portion 142 and the labyrinth forming wall 22'. More specifically, the gap 154 has a first gap 154a and a second gap 154b. The first gap 154a is defined between the rotating shaft 26 and the radial inner end surface 22a'of the labyrinth forming wall 22'so as to extend in the axial direction, and opens toward the outside of the motor 10. The second gap 154b is defined between the third wall portion 150 of the flange portion 142 and the axially upper end surface 22b'of the labyrinth forming wall 22'so as to extend in the radial direction, and is defined with the first gap 154a. Communicate.

The foreign matter receiving hole 144 is formed in the rotating shaft 26 so as to be recessed inward in the radial direction from the outer peripheral surface 26a of the rotating shaft 26, and has a gap 154 (specifically, a first gap 154a and a second gap 154b) and a gap 154b. It is open facing the reservoir hole 156. The foreign matter receiving hole 144 is an annular recess extending in the circumferential direction over the entire circumference of the outer peripheral surface 26a. In the present embodiment, a part of the foreign matter that has entered the inside of the electric motor 10 through the first gap 154a is received by the foreign matter receiving hole 144.

On the other hand, of the foreign matter that has entered the inside of the motor 10 from the first gap 154a, the portion that has not entered the foreign matter receiving hole 144 is received by the reservoir hole 156 defined inside the flange portion 142. As described above, in the present embodiment, the foreign matter that has entered the inside of the motor 10 from the first gap 154a is received by the foreign matter receiving holes 144 and the reservoir holes 156 formed in the rotor 140, and the foreign matter is received by the electric motor 10. It prevents further inward entry.

The flange portion 142 according to this embodiment may be applied to the rotor 14 shown in FIG. In this case, the flange portion 142 is arranged adjacent to the upper side of the fourth wall portion 42 of the labyrinth forming wall 22 in the axial direction. Further, the flange portion 142 according to the present embodiment may be applied to the rotor 70, 90, 100, or 120 described above. In this case, the flange portion 142 may be fixed to the outer peripheral surface 26a of the rotating shaft 26 adjacent to the upper side in the axial direction of the fourth wall portion 42 instead of the second flange portion 80 described above.

Next, the rotor 160 according to still another embodiment will be described with reference to FIG. The rotor 160 according to this embodiment is different from the rotor 140 shown in FIG. 8 in the following configuration. That is, the rotor 160 has an annular groove 162 formed in the rotating shaft 26 and the above-mentioned foreign matter receiving hole 50. The annular groove 162 is formed so as to be recessed inward from the outer peripheral surface 26a of the rotary shaft 26, and is formed so as to extend in the circumferential direction over the entire circumference of the outer peripheral surface 26a.

More specifically, the annular groove 162 extends between a pair of side surfaces 162a and 162b extending radially inward from the outer peripheral surface 26a so as to face each other in the axial direction, and the side surfaces 162a and 162b. It is defined from the bottom surface 162c. A radial inner end of the labyrinth forming wall 22'of the stator 12'is inserted into the annular groove 162.

A gap 164 is formed between the rotating shaft 26 and the labyrinth forming wall 22'. More specifically, the gap 164 has a gap 164a (second gap), a gap 164b (first gap), and a gap 164c. The gap 164a is defined between the side surface 162a of the annular groove 162 and the axially lower end surface 22c'of the labyrinth forming wall 22' so as to open outward of the motor 10 and extend in the radial direction.

The gap 164b is defined between the bottom surface 162c of the annular groove 162 and the radial inner end surface 22a'of the labyrinth forming wall 22'so as to extend in the axial direction, and communicates with the gap 164a. The gap 164c is defined between the side surface 162b of the annular groove 162 and the axially upper end surface 22b'of the labyrinth forming wall 22'so as to extend in the radial direction, and communicates with the gap 164b.

In the present embodiment, the opening 62 of the first hole 58 of the foreign matter receiving hole 50 is arranged so as to face the gap 164a. According to this configuration, the foreign matter passing through the gap 164a can be received by the foreign matter receiving hole 50, so that the foreign matter can be reliably prevented from entering the inside of the motor 10 beyond the gaps 164b and 164c.

In the present embodiment, the above-mentioned foreign matter receiving hole 72 (or 82) may be applied to the rotor 160 instead of the foreign matter receiving hole 50. In this case, the opening 78 (or 62) of the foreign matter receiving hole 72 (or 82) may be arranged so as to face the gap 164a. Further, in the present embodiment, the second flange portion 80 shown in FIG. 4 or the flange portion 142 shown in FIG. 8 may be provided adjacent to the upper side in the axial direction of the labyrinth forming wall 22'.

The foreign matter receiving hole 50, 72 or 82 described above may be configured as an annular recess like the foreign matter receiving hole 144 shown in FIG. Alternatively, the above-mentioned foreign matter receiving holes 50, 72 or 82 may be composed of only the first hole portion 58 or 76 or the communication hole 86. Moreover, the above-mentioned plug 68 may be omitted.

Further, an absorbent material (sponge, hygroscopic agent, etc.) capable of absorbing foreign matter is arranged inside the above-mentioned foreign matter receiving holes 50, 72, 82, 102 or 144 (specifically, main holes 52, 84 or 104). You may. According to this configuration, the foreign matter that has entered the foreign matter receiving holes 50, 72, 82, 102 or 144 (main holes 52, 84 or 104) is retained in the absorbing material, and the foreign matter is retained in the foreign matter receiving holes 50, 72, 82, Leakage from 102 or 144 (main hole 52, 84 or 104) can be more reliably prevented.

Further, in the above-described embodiment, the case where the lower part of the rotating shaft 26 in the axial direction (output side) is arranged so as to coincide with the lower part in the gravity direction has been described. However, the present invention is not limited to this, and the axial direction of the rotating shaft 26 may be arranged parallel to the horizontal direction, or may be arranged at an angle with respect to the direction of gravity. Further, the above-mentioned first hole portion 58 or 76 or the communication hole 86 may be provided in parallel with the radial direction. Although the present disclosure has been described above through the embodiments, the above-described embodiments do not limit the invention according to the claims.

10 Motor 12, 12'Stator 14, 70, 90, 100, 120, 140, 160 Rotor 22, 22' Labyrinth forming wall 26 Rotating shaft 30, 80, 122, 142 Flange part 44, 44a, 44b, 154, 154a, 154b, 164, 164a, 164b, 164c Gap 50, 72, 82, 102, 144 Foreign matter receiving holes 52, 84, 104 Main holes 54, 74, 86 Communication holes 58, 60, 76 Holes

Claims (11)

It ’s a motor rotor,
A rotating shaft that extends in the axial direction,
A foreign matter receiving hole formed in the rotating shaft so as to face a gap between the axial end of the stator of the motor and the rotor, and accepts foreign matter that enters the inside of the motor through the gap. And, with a rotor. The foreign matter receiving hole is
The main hole formed in the center of the rotating shaft and
The rotor according to claim 1, further comprising a communication hole that opens facing the gap and communicates the gap with the main hole. The rotor according to claim 2, wherein the main hole extends from the opening of the communication hole facing the gap to the side in the first direction in the axial direction toward the outside of the motor. The main hole is arranged at a position separated from the opening in the first direction.
The communication hole is
A first hole extending radially inward from the opening and
The rotor according to claim 3, further comprising a second hole extending from the first hole in the first direction and connected to the main hole. The rotor according to claim 4, wherein the first hole portion extends so as to be inclined in the radial direction so as to be directed in the first direction toward the inside in the radial direction. The rotor according to any one of claims 3 to 5, wherein the rotating shaft is arranged so that the first direction coincides with the lower direction of gravity. The rotor according to claim 6, wherein the main hole is defined by an inclined surface that is inclined with respect to the axial direction so as to expand outward in the radial direction toward the first direction. An annular groove extending in the circumferential direction of the outer peripheral surface is formed on the outer peripheral surface of the rotating shaft.
The rotor according to any one of claims 1 to 7, wherein the foreign matter receiving hole is formed so as to extend radially inward from the annular groove. With the stator
An electric motor comprising the rotor according to any one of claims 1 to 8, which is rotatably arranged inside the stator in the radial direction. The stator is a labyrinth forming wall provided at the end thereof, and has a first gap extending in the axial direction and a second gap communicating with the first gap and extending in the radial direction. Has a labyrinth forming wall, which forms between the rotor and the rotor.
The motor according to claim 9, wherein the foreign matter receiving hole is opened so as to face the second gap. The rotor further has a flange portion fixed to the rotating shaft so as to project radially outward from the rotating shaft.
The motor according to claim 10, wherein the labyrinth forming wall forms the first gap and the second gap with the flange portion.

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