Motor

Abstract

To provide a motor having a simple housing structure while including an air vent hole and a drain hole.SOLUTION: A motor disclosed in the present description includes a tubular housing accommodating a stator and a rotor, and a cover that closes an opening of the housing. The housing is provided with a refrigerant flow path. A hole for connecting the outside and the inside of the refrigerant flow path is disposed in each of upper and lower portions of the cover. In the motor disclosed in the present description, two holes (an air vent hole and a drain hole) are disposed in the cover. Accordingly, the structure of the housing is simple. Further, a common cover having the air vent hole and the drain hole can be used for housings of different lengths. Since the common cover can be used for housings of different lengths, the degree of freedom of design of the motor can be increased.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed in this specification relates to a motor.

Background Art

[0002] The motor is provided with a refrigerant flow path for cooling the coils of the stator. In the motor of Patent Document 1, a refrigerant flow path is provided in a housing that houses a rotor and a stator. The housing is provided with a vent hole for removing air bubbles in the refrigerant flow path. The housing may be provided with a hole (drain hole) for draining the refrigerant from the refrigerant flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Stators of different lengths require housings of different lengths. Providing vent holes and drain holes in each of the housings of different lengths makes the structure of the housing complex. This specification provides a motor that has vent holes and drain holes but has a simple housing structure.

Means for Solving the Problems

[0005] The motor disclosed in this specification includes a cylindrical housing that houses a stator and a rotor, and a cover that closes the opening of the housing. A refrigerant flow path is provided in the housing. Holes are provided in the upper and lower parts of the cover to communicate the inside and outside of the refrigerant flow path. The motor disclosed in this specification provides two holes (vent hole and drain hole) in the cover. Therefore, the structure of the housing is simplified. Furthermore, a common cover with a vent hole and a drain hole can be applied to housings of different lengths. Since a common cover can be applied to housings of different lengths, the degree of freedom in motor design can be increased.

[0006] Note that one of the two holes (air hole and drain hole) may also serve as a refrigerant supply port. The other of the two holes may also serve as a refrigerant discharge port. In addition to the two holes, two separate holes (refrigerant supply port and refrigerant discharge port) may be provided.

[0007] The details and further improvements of the technology disclosed in this specification will be described in the following "Modes for Carrying Out the Invention".

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] (First Embodiment) The motor 2 of the first embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a rear view of the motor 2. FIG. 2 is a cross-sectional view of the motor 2 cut along line II-II in FIG. 1. The motor 2 includes a rotor 3, a stator 4, a housing 20, and a pair of covers 10 and 30. The rotor 3 and the stator 4 are housed in a cylindrical housing 20. Both ends of the housing 20 in the axial direction of the axis Ax are open. One opening of the housing 20 is closed by the cover 10. The cover 10 is fixed to the housing 20 with a plurality of bolts 51. The other opening of the housing 20 is closed by the cover 30. The cover 30 is fixed to the housing 20 with a plurality of bolts 52. To distinguish the cover 10 from the cover 30, the cover 30 may be referred to as the "separate cover". The stator 4 is fixed inside the housing 20. The rotor 3 is rotatably supported by bearings provided in the covers 10 and 30.

[0010] While the motor 2 is operating, a high-voltage current flows through the coil 5 of the stator 4, so the coil 5 generates heat. To cool the coil 5, a refrigerant flow path 21 is provided in the housing 20. A liquid refrigerant flows through the refrigerant flow path 21, and the coil 5 is cooled. More specifically, cooling water flows through the refrigerant flow path 21.

[0011] The structure of the refrigerant flow path 21 will be described. A straight flow path 22 is provided inside the side wall of the housing 20. FIG. 3 shows a cross-sectional view of the motor 2 cut along line III-III in FIG. 1. FIG. 3 shows a cross-section of the side wall of the housing 20 cut along the circumferential direction. A plurality of straight flow paths 22 parallel to the axis Ax are provided on the side wall of the housing 20. One end of adjacent straight flow paths 22 is connected by a U-shaped flow path 12 provided in the cover 10. The other end of adjacent straight flow paths 22 is connected by a U-shaped flow path 32 provided in the cover 30. The U-shaped flow path 12 and the U-shaped flow path 32 alternately connect adjacent straight flow paths 22, and the U-shaped flow paths 12 and 32 and the straight flow path 22 constitute one refrigerant flow path 21.

[0012] The cover 10 is provided with two holes (vent hole 13, drain hole 14) and two other holes (refrigerant supply port 18, refrigerant discharge port 19). All of the total four holes and other holes communicate the inside and outside of the refrigerant flow path 21. A refrigerant circulation device (not shown) is connected to the refrigerant supply port 18 and the refrigerant discharge port 19. Liquid cold refrigerant is supplied from the refrigerant circulation device to the refrigerant flow path 21. The refrigerant flowing through the refrigerant flow path 21 cools the coil 5. The refrigerant that has absorbed heat from the coil 5 exits from the refrigerant discharge port 19 and returns to the refrigerant circulation device.

[0013] The vent hole 13 is normally closed by a bolt 53. The drain hole 14 is normally closed by a bolt 54. The motor 2 is arranged such that the vent hole 13 is located at the vertical upper part of the cover 10 and the drain hole 14 is located at the vertical lower part of the cover 10. In other words, the vent hole 13 is located at the upper part of the cover 10 and the drain hole 14 is located at the vertical lower part of the cover 10.

[0014] The vent hole 13 and the drain hole 14 are opened when the motor 2 is stopped to exchange the refrigerant. First, the drain hole 14 is opened to let the old refrigerant out of the refrigerant flow path 21. The drain hole 14 is closed with the bolt 54, and the vent hole 13 is opened. Refrigerant is injected into the refrigerant flow path 21 through the vent hole 13. As the refrigerant flow path 21 is filled with refrigerant, the air in the refrigerant flow path 21 is discharged to the outside through the vent hole 13. At this time, the bubbles contained in the refrigerant are also discharged through the vent hole 13. When the vent hole 13 is closed with the bolt 53, preparations are complete for driving the motor 2.

[0015] In FIG. 3, the symbol T indicates the position of the vertical upper part of the motor 2, and the symbol B indicates the position of the vertical lower part of the motor 2. Also in FIG. 3, it is shown that the vent hole 13 is located at the vertical upper part of the cover 10 and the drain hole 14 is located at the vertical lower part of the cover 10. The refrigerant supply port 18 and the refrigerant discharge port 19 are located between the vent hole 13 and the drain hole 14 in the vertical direction.

[0016] (Second Embodiment) Fig. 4 shows a cross-sectional view of the motor 102 of the second embodiment. Fig. 4 is a figure corresponding to Fig. 2. In the motor 102, a bolt 53 that closes the air vent hole 13 fixes the cable bracket 103 to the cover 10. The cable bracket 103 supports a power cable 104 for supplying a three-phase alternating current to the coil 5 of the stator 4. Except for including the cable bracket 103, the structure of the motor 102 is the same as that of the motor 2.

[0017] Enumerate some features and their effects of the motors 2 and 102 described in the embodiments. An air vent hole 13 is provided at the upper part in the vertical direction of the cover 10, and a drain hole 14 is provided at the lower part in the vertical direction. In other words, the air vent hole 13 and the drain hole 14 are located so as to sandwich the axis Ax. In addition to the air vent hole 13 and the drain hole 14, the cover 10 is provided with other holes (a refrigerant supply port 18 and a refrigerant discharge port 19) that communicate the inside and outside of the refrigerant flow path 21. The diameters of the air vent hole 13 and the drain hole 14 are smaller than the diameters of the refrigerant supply port 18 and the refrigerant discharge port 19. The two holes (the air vent hole 13 and the drain hole 14) and the two other holes (the refrigerant supply port 18 and the refrigerant discharge port 19) all communicate the inside and outside of the refrigerant flow path 21. The other holes (the refrigerant supply port 18 and the refrigerant discharge port 19) are located between the air vent hole 13 and the drain hole 14 in the vertical direction (up and down direction).

[0018] The cylindrical housing 20 of the motors 2 and 102 is not provided with holes. The structure of the housing 20 becomes simple. Housings 20 different according to the length of the stator 4 are prepared. A common cover 10 can be adopted for the housings 20 with different lengths. Since the cover 10 can be made common for the housings 20 with different lengths, the design freedom of the motors 2 and 102 can be increased.

[0019] By providing two holes (the air vent hole 13 and the drain hole 14) and two other holes (the refrigerant supply port 18 and the refrigerant discharge port 19) in the cover 10, the degree of freedom in the installation positions of the refrigerant supply port 18 and the refrigerant discharge port 19 increases.

[0020] In the motor 102 of the second embodiment, the bolt 53 that fixes the component of the motor (cable bracket 103) to the cover 10 closes the air vent hole 13. The bolt 53 that closes the air vent hole 13 also serves as the bolt that fixes the component. This structure contributes to reducing the number of parts of the motor 102.

[0021] Points to note regarding the technology described in the embodiment are described. The drain hole 14 may also serve as the refrigerant supply port 18, and the air vent hole 13 may also serve as the refrigerant discharge port 19. That is, only two holes may be provided in the cover 10. In that case, both holes cannot be closed. The refrigerant enters the refrigerant flow path 21 from the lower refrigerant supply port 18 (drain hole 14) and exits from the upper refrigerant discharge port 19 (air vent hole 13). The bubbles contained in the refrigerant naturally exit from the refrigerant discharge port 19 (air vent hole 13) along with the flow of the refrigerant.

[0022] Either the air vent hole 13 or the drain hole 14 may also serve as the refrigerant supply port 18. Either the air vent hole 13 or the drain hole 14 may also serve as the refrigerant discharge port 19.

[0023] The refrigerant supply port 18 and the refrigerant discharge port 19 may be provided in the other cover 30 or the housing 20. However, it is desirable that the refrigerant supply port 18 and the refrigerant discharge port 19 be provided in the cover 10 together with the air vent hole 13 and the drain hole 14. By providing four holes in one cover 10, the structures of the housing 20 and the other cover 30 can be simplified.

[0024] The cover 10 closes one opening of the cylindrical housing 20. The other opening of the housing 20 is closed by another cover 30. The housing 20 may be a bottomed cylinder. In that case, the motor includes only one cover 10. The motors 2 and 102 of the embodiment include a refrigerant flow path 21 composed of a plurality of straight flow paths 22 and a plurality of U-shaped flow paths 12 and 32. The refrigerant flow path 21 may be provided in the wall of the housing 20, and its shape may be any shape.

[0025] The bolt 54 that closes the drain hole 14 may fix the components of the motor. The bolts 53 and 54 may fix the components other than the cable bracket 103 to the cover 30.

[0026] As described above, the specific examples of the present invention have been described in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in this specification or the drawings can achieve a plurality of purposes simultaneously, and achieving one of those purposes itself has technical utility.

Explanation of Reference Numerals

[0027] 2, 102: motor 3: rotor 4: stator 5: coil 10, 30: cover 12, 32: U-shaped flow path 13: air vent hole 14: drain hole 18: refrigerant supply port 19: refrigerant discharge port 20: housing 21: refrigerant flow path 22: straight flow path 51, 52, 53, 54: bolts 103: cable bracket 104: power cable

Claims

1. A cylindrical housing that houses a stator and a rotor, A cover that closes the opening of the housing, and is provided with, The housing is provided with a refrigerant flow path, A motor in which holes for communicating the inside and outside of the refrigerant flow path are provided in each of the upper and lower portions of the cover.

2. The motor according to claim 1, wherein a separate hole for communicating the inside and outside of the refrigerant flow path is provided in one of the housing and the cover.

3. The motor according to claim 2, wherein the separate hole is provided in the cover.

4. The motor according to claim 3, wherein the separate hole is located between the two holes in the vertical direction.

5. The motor according to claim 1, wherein a bolt that fixes a component to the cover closes one of the holes.

6. The motor according to claim 1, further comprising a separate cover that closes the other opening of the housing.

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