Current collector cooling structure and induction motor

Abstract

To provide a power collector cooling structure improved in cooling of a brush portion.SOLUTION: A power collector cooling structure comprises: a slip ring which is rotatable with a central axis defined as an axis of rotation; a brush in contact with the slip ring; a frame which covers the slip ring and the brush from the outside in a radial direction and includes an air-intake which is opened outside in the radial direction and closer to one side in an axial direction than the brush; and a first cutoff section which regulates a circumferential direction range, in which a coolant flowing from the air-intake into the frame flows, within a circumferential direction range in which the brush is disposed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a current collector cooling structure, for example, a structure for cooling a current collector of an induction motor, and an induction motor equipped with a current collector. [Background technology]

[0002] For example, in an induction motor, a circuit provided in the rotating part that rotates together with the rotor and a circuit provided in the fixed part that does not rotate are electrically connected or disconnected. In order to electrically connect or disconnect the rotating part and the fixed part, a current collector using a brush and a slip ring is used. The contact part of the brush with the slip ring generates heat as it operates, so it needs to be cooled. The invention described in Patent Document 1 attempts to cool the brush part by blowing air along the shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3199907 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when blowing air as described in Patent Document 1, the air tends to pass through areas in the circumferential direction where there are no brushes, and the air is dispersed, making it impossible to cool the brush part in a concentrated manner, leaving room for improvement in cooling the brush part.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a current collector cooling structure that is improved in terms of cooling the brush portion. [Means for solving the problem]

[0006] A current collector cooling structure according to one aspect of the present invention includes a slip ring rotatable about a central axis as a rotation axis, a brush in contact with the slip ring, a frame covering the slip ring and the brush from the radial outside and having an air intake port that opens radially outward on one axial side of the brush, and a first blocking portion that restricts a circumferential range in which a refrigerant that has flowed into the frame from the air intake port flows to the circumferential range in which the brush is disposed. The circumferential position of the air intake port is a position that faces in the radial direction the circumferential range restricted by the first blocking portion, and one axial side of the brush is open toward the air intake port. .

[0007] In one embodiment of the current collector cooling structure described above, a top portion is provided that covers the slip ring and the brush from one axial side, and the top portion has a second blocking portion that restricts the flow range of the refrigerant that flows into the frame from the intake port to be radially outward of the brush on one axial side of the brush.

[0008] In the current collector cooling structure of one aspect described above, a third blocking portion is provided that restricts the flow range of the refrigerant that flows into the frame from the intake port to one axial side of the brush on the other axial side of the brush.

[0009] In one aspect of the current collector cooling structure described above, a bottom portion is provided that covers the slip ring and the brush from the other axial side, and the bottom portion has a through hole that penetrates axially radially inward of the brush and exhausts refrigerant that has passed through the brush.

[0010] In the current collector cooling structure according to the above aspect, the bottom portion has an exhaust port that exhausts the refrigerant that has flowed in from one axial side of the through hole to the outside in the radial direction.

[0011] An induction motor according to one aspect of the present invention includes a current collector having the current collector cooling structure according to the above aspect. [Effects of the Invention]

[0012] According to one aspect of the present invention, it is possible to provide a current collector cooling structure that is improved in terms of cooling the brush portion. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view of a current collector according to a first embodiment of the present invention. [Figure 2] 2 is a perspective view showing the current collector 100 of FIG. 1 excluding a top part 110 and a frame 120. FIG. [Figure 3] 2 is a perspective view showing the current collector 100 of FIG. 1 excluding a frame 120, a terminal 141, a terminal 142, and a terminal 143. FIG. [Figure 4] FIG. 4 is a side view of FIG. 3 as seen from the +Y side. [Figure 5] 1. FIG. 2 is a plan view of the current collector 100 of FIG. 1, excluding the top portion 110 and the lead connection portion 124, as viewed from the +Z side. [Figure 6] 1A and 1B are schematic diagrams showing the air flow in Example 1, where (A) is a plan view and (B) is a side view. [Figure 7] 10A and 10B are schematic diagrams showing the air flow in Example 2, where (A) is a plan view and (B) is a side view. [Figure 8] 10A and 10B are schematic diagrams showing the air flow in Example 3, where (A) is a plan view and (B) is a side view. [Figure 9] 10A and 10B are schematic diagrams showing the air flow in Example 4, where (A) is a plan view and (B) is a side view. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, a current collector cooling structure according to an embodiment of the present invention will be described with reference to the drawings. The current collector cooling structure according to the present embodiment is applicable to a current collector attached to the shaft of an induction motor, for example. Note that in the following drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0015] In addition, in the drawings, an XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate. In the XYZ coordinate system, the Z axis direction is parallel to the axis of the central axis J shown in Figure 1. The X axis direction is the radial direction relative to the central axis J, which is the left-right direction in Figure 1. The Y axis direction is perpendicular to both the Z axis direction and the X axis direction. In each of the X axis, Y axis, and Z axis directions, the side indicated by the arrow in the drawing is the positive side, and the opposite side is the negative side.

[0016] In the following description, the positive side (+Z side) in the Z-axis direction will be referred to as "one side," and the negative side (-Z side) in the Z-axis direction will be referred to as "the other side." Note that "one side" and "the other side" are names used merely for the purpose of explanation and do not limit the actual positional relationship or direction. Furthermore, unless otherwise specified, the direction parallel to the central axis J (Z-axis direction) will be referred to simply as "axial direction," the radial direction centered on the central axis J will be referred to simply as "radial direction," and the circumferential direction centered on the central axis J, i.e., around the axis of the central axis J, will be referred to simply as "circumferential direction." The side approaching the central axis J in the radial direction will be referred to as "radially inner," and the side away from the central axis J will be referred to as "radially outer."

[0017] In this specification, "extending in the axial direction" includes not only extending strictly in the axial direction (Z-axis direction) but also extending in a direction tilted by less than 45° with respect to the axial direction. In addition, in this specification, "extending in the radial direction" includes not only extending strictly in the radial direction, i.e., in a direction perpendicular to the axial direction (Z-axis direction), but also extending in a direction tilted by less than 45° with respect to the radial direction. Furthermore, "parallel" includes not only being strictly parallel but also being tilted by an angle of less than 45° with respect to each other.

[0018] Furthermore, in this specification, terms such as top, bottom, nadir, etc. merely indicate positions for the purpose of explanation of each component, and do not limit the actual installation position, etc. [Example]

[0019] FIG. 1 is a perspective view of a current collector according to a first embodiment of the present invention. The current collector 100 has a top portion 110, a frame 120, and a bottom portion 150. The top portion 110, the frame 120, and the bottom portion 150 form a case that houses slip rings 128a, 128b, and 128c, which will be described later. The slip rings 128a, 128b, and 128c correspond to the three phases, respectively. The current collector 100 has terminals 141, 142, and 143, which correspond to the three phases, respectively. The terminals 141, 142, and 143 are exposed to the outside of the frame 120.

[0020] The frame 120 is a cylindrical member that is open on both one axial side and the other axial side. The top portion 110 closes the opening on one axial side of the frame 120. The bottom portion 150 closes the opening on the other axial side of the frame 120.

[0021] The frame 120 has an intake port 121, an intake port 122, and an intake port 123 on one axial side. The frame 120 opens radially outward at the intake ports 121, 122, and 123. The top portion 110 is a member having a circular surface perpendicular to the axial direction. The bottom portion 150 has a cylindrical side plate 151.

[0022] 2 is a perspective view showing the current collector 100 of FIG. 1 excluding the top portion 110 and the frame 120. The current collector 100 has a lead connection portion 124 and a terminal 129 on one axial side of the slip rings 128a, 128b, and 128c. Three terminals 129 are provided, one for each of the three phases.

[0023] The current collector 100 has a plate member 125. The plate member 125 has a flat plate shape. The plate member 125 has one axial side of the flat plate oriented parallel to the axial direction and perpendicular to the radial direction, and the other axial side of the flat plate bent radially outward to form leg portions 125a and interrupting portions 125b. The leg portions 125a have a plate surface extending in a direction perpendicular to the axial direction. The interrupting portions 125b have a plate surface extending in a direction parallel to the axial direction and perpendicular to the radial direction.

[0024] The current collector 100 includes plate members 126 and 127. Plate member 126 has a flat plate shape. Plate member 126 is formed by arranging the circumferential center surface of the flat plate in a direction perpendicular to the axial direction and bending both circumferential ends of the flat plate toward one side in the axial direction, thereby forming interrupter portions 126a, 126b, and 126c. Interrupter portion 126a has a plate surface extending in a direction perpendicular to the axial direction. Interrupter portion 126b has a plate surface extending in a direction parallel to the axial direction and perpendicular to the circumferential direction. Interrupter portion 126c has a plate surface extending in a direction parallel to the axial direction and perpendicular to the circumferential direction. Interrupter portions 126a and 126b are examples of a first interrupter portion. Interrupter portion 126c is an example of a third interrupter portion.

[0025] Plate member 127 has a flat plate shape. Plate member 127 is arranged with the circumferential center surface of the flat plate oriented perpendicular to the axial direction, and both circumferential ends of the flat plate are bent to one side in the axial direction to form blocking portions 127a, 127b, and 127c. Blocking portion 127a has a plate surface that extends in a direction perpendicular to the axial direction. Blocking portion 127b has a plate surface that extends in a direction parallel to the axial direction and perpendicular to the circumferential direction. Blocking portion 127c has a plate surface that extends in a direction parallel to the axial direction and perpendicular to the circumferential direction.

[0026] FIG. 3 is a perspective view showing the current collector 100 of FIG. 1 excluding the frame 120, terminals 141, 142, and 143. FIG. 4 is a side view of FIG. 3 as viewed from the +Y side. The top portion 110 has a top plate portion 110a, which is a circular flat plate member perpendicular to the axial direction. The top portion 110 has interrupter portions 110b, 110c, and 110d extending from the other axial side surface of the top plate portion 110a to the other axial side. The interrupter portions 110b, 110c, and 110d are arranged at positions corresponding to the plate member 126. The interrupter portion 110b is an example of a second interrupter. The top portion 110 also has an interrupter portion arranged at a position corresponding to the plate member 127, but since these are similar to the interrupter portions 110b, 110c, and 110d, their description will be omitted.

[0027] Blocking portion 110b has a surface parallel to the axial direction and along the circumferential direction. Blocking portion 110c has a surface parallel to the axial direction and perpendicular to the circumferential direction. Blocking portion 110d has a surface parallel to the axial direction and perpendicular to the circumferential direction. Blocking portion 110b is the same plate member as blocking portions 110c and 110d.

[0028] The circumferential position of the blocking portion 110c coincides with the circumferential position of the blocking portion 126b. The radially inner end and radially outer end of the blocking portion 110c coincide with the radially inner end and radially outer end of the blocking portion 126b. The circumferential position of the blocking portion 110d coincides with the circumferential position of the blocking portion 126c. The radially inner end and radially outer end of the blocking portion 110d coincide with the radially inner end and radially outer end of the blocking portion 126c. One circumferential end of the blocking portion 110c coincides with the radially inner end of the blocking portion 110c. The other circumferential end of the blocking portion 110c coincides with the radially inner end of the blocking portion 110d.

[0029] The other axial end of blocking portion 110c coincides with one axial end of blocking portion 126b. The other axial end of blocking portion 110d coincides with one axial end of blocking portion 126c. The other axial end of blocking portion 110b coincides with the other axial ends of blocking portions 110c and 110d.

[0030] The bottom portion 150 has a cylindrical side plate 151, an upper plate 152, and a lower plate 153. The cylindrical side plate 151 has an exhaust port 151a that opens radially outward. Multiple exhaust ports 151a are arranged circumferentially. The upper plate 152 has a through-hole 152a that penetrates in the axial direction. The lower plate 153 has a through-hole (not shown) that penetrates in the axial direction. A shaft (not shown) penetrates the through-hole of the lower plate 153, the cylindrical portion of the side plate 151, and the through-hole 152a of the upper plate 152. The shaft extends along the central axis J. The shaft is coaxial with the central axis J.

[0031] Slip rings 128a, 128b, and 128c fit onto the shaft and rotate together with it. Slip rings 128a, 128b, and 128c are coaxial with the shaft. Frame 120 is coaxial with the shaft. Slip ring 128a is located on one side of slip ring 128b in the axial direction. Slip ring 128b is located on one side of slip ring 128c in the axial direction.

[0032] The interrupter 125b has through holes 125c through which the terminals 141, 142, and 143 pass. The leg portion 125a is fixed to a surface on one axial side of the upper plate 152. The interrupter 126a is located on one axial side of the surface on one axial side of the upper plate 152. The interrupter 127a is located on one axial side of the surface on one axial side of the upper plate 152. The one axial side end of the interrupter 125b is located on one axial side of the slip ring 128a. The one axial side end of the interrupter 125b is located on the other axial side of the lead connection portion 124.

[0033] FIG. 5 is a plan view of the current collector 100 of FIG. 1 , excluding the top portion 110 and the lead connection portion 124, as viewed from the +Z side. Brushes contact the outer circumferential surfaces of the slip rings 128a, 128b, and 128c. FIG. 5 illustrates brushes 131, 132, 133, and 134 that contact the outer circumferential surface of the slip ring 128b. The circumferential positions of the brushes that contact the slip rings 128b and 128c are the same as those of the brushes 131, 132, 133, and 134. In this embodiment, the brushes 131 and 132 are positioned within a 120° range in the circumferential direction, and the brushes 133 and 134 are positioned within another 120° range in the circumferential direction. Furthermore, the brushes 131, 132, 133, and 134 are all positioned within a 180° range in the circumferential direction.

[0034] Frame 120 covers, from the radial outside, brushes 131, 132, 133, and 134, as well as the brushes in contact with slip rings 128b and 128c. Brushes 131, 132, 133, and 134 are located on one axial side of the brushes in contact with slip rings 128b and 128c.

[0035] Frame 120 has air intakes 121, 122, and 123 on one axial side of brushes 131, 132, 133, and 134, and brushes in contact with slip rings 128b and 128c. To cool the inside of frame 120, air is blown into frame 120 through air intakes 121, 122, and 123 to allow air to flow in. The air in this case is an example of a refrigerant that cools the inside of frame 120.

[0036] When air is introduced into the frame 120 through the intake port 121, the air is blocked by the blocking portion 125b from flowing toward the other axial side of one axial end of the blocking portion 125b, and flows toward the lead connection portion 124 and the terminal 129, cooling the lead connection portion 124 and the terminal 129.

[0037] Brushes 131 and 132 are located circumferentially between blocking portion 110c and blocking portion 126b and blocking portion 110d and blocking portion 126c. When air flows into frame 120 from air intake 122, the circumferential range of the air flow is restricted by blocking portions 110c, 110d, 126b, and 126c. If the gap between blocking portions 110c and 126b and blocking portions 110d and 126c is too wide, brushes 131 and 132 cannot be cooled in a concentrated manner. Therefore, it is desirable that both ends of the range restricted by blocking portions 110c and 126b and blocking portions 110d and 126c roughly coincide with both circumferential ends of brushes 131 and 132. Blocking portion 110c, blocking portion 110d, blocking portion 126b and blocking portion 126c are examples of a first blocking portion that restricts the circumferential range in which air flowing into frame 120 from air intake port 122 flows to the circumferential range in which brushes 131 and 132 are arranged.

[0038] The other axial end of cutoff portion 110b is located on one axial side of brushes 131 and 132. The other axial end of cutoff portion 110b is located on the other axial side of lead connection portion 124. Cutoff portion 110b is an example of a second cutoff portion that restricts the flow range of air that has flowed into frame 120 from air intake port 122 to one axial side of brushes 131 and 132, radially outward of brushes 131 and 132. This allows for concentrated cooling of the brushes in contact with slip rings 128a, 128b, and 128c.

[0039] The surface of the blocking portion 126a facing one axial side is located on the other axial side of the brushes in contact with the slip ring 128c. If the axial position of the blocking portion 126a is further to the other axial side than the brushes in contact with the slip ring 128c, concentrated cooling of the brushes in contact with the slip ring 128a, the slip ring 128b, and the slip ring 128c will be impossible. Therefore, it is desirable that the axial position of the surface of the blocking portion 126a facing one axial side coincides with the other end of the brush in contact with the slip ring 128c. The blocking portion 126a is an example of a third blocking portion that restricts the flow range of air flowing into the frame 120 from the air intake port 122 to one axial side of the brushes in contact with the slip ring 128c on the other axial side of the brushes in contact with the slip ring 128c. This allows concentrated cooling of the brushes in contact with the slip ring 128a, the slip ring 128b, and the slip ring 128c.

[0040] Air flowing into the frame 120 from the intake port 122 cools the brushes in contact with the slip rings 128a, 128b, and 128c, and flows to the other axial side because one axial side is blocked by the top plate portion 110a. After cooling the brushes in contact with the slip rings 128a, 128b, and 128c, the air exits the other axial side through a through-hole 152a in the top plate 152 located on the other axial side of the slip ring 128c. The through-hole 152a passes through the axial direction radially inward of the brushes in contact with the slip rings 128a, 128b, and 128c. This improves the situation where the air intended to cool the brushes passes radially outward of the brushes, preventing them from being cooled.

[0041] The air that has escaped through the through-hole 152a to the other axial side is exhausted radially outward from the exhaust port 151a of the side plate 151. The exhaust port 151a faces radially outward, which allows for smooth exhaust even when exhaust along the axial direction is obstructed by a shaft or the like.

[0042] Up to now, the brushes 131 and 132 have been described, but the configuration and operation of the brushes 133 and 134 are similar, so a description of the brushes 133 and 134 will be omitted.

[0043] 6(A) and 6(B) are schematic diagrams showing the air flow in Example 1, with Fig. 6(A) being a plan view and Fig. 6(B) being a side view. In the figures, solid arrows 160 indicate the flow of intake air, and dashed arrows 170 indicate the flow of exhaust air.

[0044] In the first embodiment, 4x3 phase brushes are arranged within a 180° circumferential range. 2x3 phase brushes are arranged in one blocking area blocked by multiple blocking sections. The intake air is restricted in the circumferential direction by blocking sections 126b and 126c, and in the axial direction by blocking sections 110b and 126a, which allows for concentrated cooling of the brushes in contact with slip rings 128a, 128b, and 128c, improving cooling efficiency. [Example]

[0045] 7(A) and 7(B) are schematic diagrams showing the air flow in Example 2, with FIG. 7(A) being a plan view and FIG. 7(B) being a side view. In Example 2, the arrangement of the brushes and blocking units is different from that in Example 1. In the figures, solid arrows 260 indicate the flow of intake air, and dashed arrows 270 indicate the flow of exhaust air. Blocking unit 291 is an example of a first blocking unit. Blocking unit 292 is an example of a second blocking unit. Blocking unit 293 is an example of a third blocking unit.

[0046] Of brushes 231, 232, 233, and 234, brushes 231 and 232 are arranged in one blocking area 281, and brushes 233 and 234 are arranged in another blocking area. The blocking areas face each other in the circumferential direction. Also, on the outside of each of the two blocking areas, a blocking portion is provided that extends radially inward from the brush to form blocking area 282, and an exhaust path is formed.

[0047] In other words, in Example 2, of the 4x3 phase brushes, 2x3 phase brushes and 2x3 phase brushes are arranged in circumferentially opposing positions. The 2x3 phase brushes are arranged in one blocking area. A shielding section is provided outside the blocking area, extending radially inward beyond the blocking section that forms the two blocking areas, forming an air exhaust path.

[0048] In the case of the second embodiment, the air is passed through the brush intensively, and the cooling efficiency can be improved. [Example]

[0049] 8(A) and 8(B) are schematic diagrams showing the air flow in Example 3, with FIG. 8(A) being a plan view and FIG. 8(B) being a side view. In Example 3, the arrangement of the brushes and blocking units is the same as in Example 2, but the direction of the air is different. In the figure, solid arrow 360 indicates the flow of intake air, and dashed arrow 370 indicates the flow of exhaust air. Blocking unit 391 is an example of a first blocking unit. Blocking unit 392 is an example of a second blocking unit. Blocking unit 393 is an example of a third blocking unit.

[0050] Of brushes 231, 232, 233, and 234, brushes 231 and 232 are arranged in one blocking area 281, and brushes 233 and 234 are arranged in another blocking area. The blocking areas face each other in the circumferential direction. In addition, blocking portions that extend radially inward from the brushes are provided on the outside of each of the two blocking areas to form blocking areas 282, and an intake path is formed.

[0051] In Example 3, two 2x3 phase brushes are arranged circumferentially opposite each other among the 4x3 phase brushes. The 2x3 phase brushes are arranged in one blocking area. A shielding section is provided outside the blocking area, extending radially inward beyond the blocking section that forms the two blocking areas, forming an air intake path.

[0052] In the case of the third embodiment, the air is passed through the brush intensively, and the cooling efficiency can be improved. [Example]

[0053] 9(A) and 9(B) are schematic diagrams showing the air flow in Example 4, with FIG. 9(A) being a plan view and FIG. 9(B) being a side view. In Example 4, the arrangement of the brushes and blocking units is the same as in Example 2, but the arrangement of the brushes and blocking units is different from that in the other examples. In the figures, solid arrow 460 indicates the flow of intake air, and dashed arrow 470 indicates the flow of exhaust air. Blocking unit 491 is an example of a first blocking unit. Blocking unit 493 is an example of a third blocking unit.

[0054] Of brush 431, brush 432, brush 433, and brush 434, brush 432 and brush 433 are arranged in one blocking area 481, brush 431 is arranged in another blocking area 482, and brush 434 is arranged in another blocking area 483. In addition, blocking parts that extend radially inward from the brushes are provided outside the three blocking areas to form blocking areas 484 and 485, and exhaust paths are formed.

[0055] That is, in Example 4, 4x3 phase brushes are arranged within a 180° circumferential range. 2x3 phases are arranged in one blocking area. 1x3 phases are arranged in the two blocking areas on either side of that. Shielding sections are provided outside the three blocking areas, extending radially inward beyond the blocking sections that form the three blocking areas, forming an air exhaust path.

[0056] In the case of the fourth embodiment, the air is passed through the brush intensively, and the cooling efficiency can be improved.

[0057] The present invention is not limited to the above-described embodiments, and various improvements and design changes may be made without departing from the spirit of the present invention. In addition, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0058] 100...current collector, 110...top part, 120...frame, 150...bottom part

Claims

1. a slip ring that can rotate around a central axis; a brush in contact with the slip ring; a frame that covers the slip ring and the brush from the radially outer side and has an intake port that opens radially outward on one axial side of the brush; a first blocking portion that limits the circumferential range in which the refrigerant that has flowed into the frame from the intake port flows to a circumferential range in which the brushes are disposed; Equipped with a circumferential position of the intake port is a position radially opposite to a circumferential range restricted by the first blocking portion, One axial side of the brush is open toward the air intake port. Current collector cooling structure.

2. a top portion that covers the slip ring and the brush from one axial side; The ceiling portion has a second blocking portion that restricts the flow range of the refrigerant that has flowed into the frame from the intake port to a position radially outward of the brush on one axial side of the brush. The current collector cooling structure according to claim 1 .

3. a third blocking portion that limits the flow range of the refrigerant that has flowed into the frame from the intake port to one axial side of the brush on the other axial side of the brush; The current collector cooling structure according to claim 1 or 2.

4. a bottom portion that covers the slip ring and the brush from the other axial side; The bottom portion has a through hole that penetrates the bottom portion in the axial direction radially inward of the brush and that exhausts refrigerant that has passed through the brush. The current collector cooling structure according to claim 1 .

5. The bottom portion has an exhaust port that exhausts the refrigerant that has flowed in from one axial side of the through hole to the radially outward side. The current collector cooling structure according to claim 4 .

6. An induction motor comprising a current collector having the current collector cooling structure according to claim 1.

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