rotating electrical machines

Abstract

To provide a rotary electric machine that improves cooling efficiency by expanding a cooling range and smoothly flowing a refrigerant.SOLUTION: A rotary electric machine casing 22 has a flow path forming wall 420 of which at least a part is spirally extended at a constant inclination angle between an upstream end and a downstream end of a spiral passage. The spiral passage 412 has first and second widened regions 441 and 442. First and second rectifying partition walls 451 and 452 extending along a spiral passage 412 are formed in the first and second widened regions 441 and 442.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a rotating electric machine. [Background technology]

[0002] For example, the following Patent Documents 1 and 2 disclose cooling structures for rotating electrical machines. The water-cooled motor disclosed in Patent Document 1 has a casing with a cooling passage formed by a spiral partition wall inclined at a certain angle. In the water-cooled motor disclosed in Patent Document 2, the cooling passage is formed by a horizontal passage and a partially inclined passage to distribute the coolant from the vicinity of the inlet to the vicinity of the outlet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5717669 [Patent Document 2] Patent No. 6302736 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the refrigerant does not reach both ends of the casing (near the inlet and outlet), leaving room for improvement in cooling performance.In Patent Document 2, the cooling passage has a large crank-shaped bend in the middle, making it difficult for the refrigerant to flow smoothly.

[0005] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] One aspect of the present invention is a rotating electric machine that includes a casing that houses a rotor and a stator, the casing having a spiral passage through which a liquid refrigerant flows, the casing having a flow path forming wall that extends spirally at a constant inclination angle at least in part between an upstream end and a downstream end of the spiral passage, the spiral passage having a widening region in which a flow path width of adjacent flow path forming walls in the axial direction of the casing is larger than other parts, the widening region is formed on at least one end side of the spiral passage in the axial direction, a flow straightening partition wall is formed in the widening region extending along the spiral passage, and the widening region has a branching portion that branches the flow of the refrigerant by an upstream end of the flow straightening partition wall, and a merging portion that merges the refrigerant by a downstream end of the flow straightening partition wall. [Effects of the Invention]

[0007] According to the rotating electric machine of the present invention, the provision of the flow straightening partition wall in the widened region of the spiral passage prevents the refrigerant flow from becoming uneven in the widened portion of the passage, and allows the refrigerant to be distributed throughout the entire passage of the spiral passage. This allows the refrigerant to flow smoothly while expanding the cooling area, thereby improving cooling efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic overall view of a drive unit equipped with a rotating electric machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the flow path shape of the first cooling passage including the spiral passage. [Figure 3] FIG. 3 is a side view of the rotating electrical machine casing seen through the cylindrical cover (a side view seen from the direction of arrow A in FIG. 2). [Figure 4] FIG. 4 is a schematic diagram of a propeller device with a drive unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] The drive unit 10 shown in FIG. 1 includes a rotating electric machine 12, a transmission 14 integrated with the rotating electric machine 12, and a cooling structure 15 that cools the rotating electric machine 12 and the transmission 14. This drive unit 10 is used with the rotation axis AX of the rotating electric machine 12 (hereinafter simply referred to as "axis AX") facing up or down. Note that "up or down" does not only mean the strict vertical direction, but also includes a direction slightly tilted relative to the vertical direction. The use of the drive unit 10 is not particularly limited, but it can be used, for example, as a power source for driving a propeller 106 of a vertical take-off and landing aircraft (see FIG. 4).

[0010] The rotating electric machine 12 is an electric motor. The rotating electric machine 12 has a rotatably supported shaft 16, a rotor 18 fixed to the shaft 16, a stator 20 surrounding the rotor 18, and a rotating electric machine casing 22 that houses the shaft 16, the rotor 18, and the stator 20. Hereinafter, the term "axial direction" refers to the axial direction of the rotating electric machine 12, the shaft 16, the rotor 18, the stator 20, or the rotating electric machine casing 22.

[0011] The rotor 18 is disposed on the axis AX of the rotating electric machine 12. Although not shown in detail, the rotor 18 has a rotor core made of, for example, laminated steel plates, and magnets fixed to the rotor core. The shaft 16 and the rotor 18 rotate integrally. The rotor 18 is rotatably supported by bearings 24 and 26 disposed at one end and the other end of a rotating electric machine casing 22, respectively.

[0012] The stator 20 is formed in a hollow cylindrical shape and is fixed to the inner circumferential surface of a rotating electrical machine casing 22. Although not shown in detail, the stator 20 has a stator core and a coil held by the stator core. Power is supplied to the stator 20 from a battery (not shown), and a current flows through the coil, generating a magnetic field, which drives the rotor 18 and the shaft 16 to rotate.

[0013] The rotating electrical machine casing 22 has a cylindrical peripheral wall portion 28 that surrounds the stator 20, a ceiling portion 32 that forms one end (upper end) of the rotating electrical machine casing 22, and a bottom wall portion 30 that forms the other end (lower end) of the rotating electrical machine casing 22. The peripheral wall portion 28 has a peripheral wall main body 36 that has a spiral groove 34 formed on its outer circumferential surface, and a cylindrical cover 38 that surrounds the peripheral wall main body 36.

[0014] The rotating electrical machine 12 is provided with a first cooling passage 41 of the cooling structure 15. The first cooling passage 41 cools the rotating electrical machine 12. A liquid refrigerant (for example, water or antifreeze) is supplied to the first cooling passage 41.

[0015] The first cooling passage 41 has an inlet passage 411, a spiral passage 412, and a discharge passage 413. The inlet passage 411 introduces the refrigerant into the rotating electric machine casing 22. The inlet passage 411 communicates with an upstream end 412a of the spiral passage 412. The inlet passage 411 is a tangential hole that penetrates the outer periphery of the rotating electric machine casing 22 in the tangential direction (see FIG. 2). Note that the inlet passage 411 may also be an axial hole that penetrates the bottom wall portion 30 of the rotating electric machine casing 22 in the axial direction.

[0016] The inlet passage 411 is provided in the lower part of the rotary electric machine casing 22 in an operating state in which the axis AX of the rotary electric machine 12 faces the vertical direction. In this embodiment, the inlet passage 411 is formed in an inlet port 40 provided in the lower part of the cylindrical cover 38. A supply line 612 of the refrigerant circulation device 60 is connected to the inlet port 40.

[0017] In this embodiment, a spiral passage 412 is formed between the peripheral wall main body 36 and the cylindrical cover 38. The lower end of the spiral passage 412 is an upstream end 412a of the spiral passage 412. The upper end of the spiral passage 412 is a downstream end 412b of the spiral passage 412.

[0018] As shown in FIG. 2, the spiral passage 412 extends spirally inside the peripheral wall portion 28 of the rotary electric machine casing 22 on the downstream side of the inlet passage 411 and centered on the axis AX of the rotary electric machine 12 .

[0019] As shown in FIG. 3 , the rotary electric machine casing 22 has a flow path forming wall 420, at least a portion of which extends spirally at a constant inclination angle between an upstream end 412a and a downstream end 412b of a spiral passage 412. The spiral passage 412 has widened regions (first widened region 441 and second widened region 442) in which the flow path width of adjacent flow path forming walls 420 in the axial direction of the rotary electric machine casing 22 is larger than the other portions. The widened regions are formed on at least one end side of the spiral passage 412 in the axial direction. Flow rectifying partition walls (first flow rectifying partition wall 451 and second flow rectifying partition wall 452) extending along the spiral passage 412 are formed in the widened regions. The flow rectifying partition walls are spaced apart from the flow path forming wall 420.

[0020] The flow passage forming wall 420 has a first end forming wall 431 that forms one end of the spiral passage 412 in the axial direction, and a second end forming wall 432 that forms the other end of the spiral passage 412 in the axial direction. The first end forming wall 431 and the second end forming wall 432 extend parallel to the circumferential direction of the rotating electrical machine casing 22.

[0021] In this embodiment, the spiral passage 412 has a first widening region 441 provided at one end of the spiral passage 412 in the axial direction, and a second widening region 442 provided at the other end of the spiral passage 412 in the axial direction. The spiral passage 412 has an intermediate region 443 extending spirally between the first widening region 441 and the second widening region 442. A first flow rectifying partition 451 is arranged in the first widening region 441, and a second flow rectifying partition 452 is arranged in the second widening region 442.

[0022] The flow channel widths of the first widened region 441 and the second widened region 442 are larger than the flow channel width T of the intermediate region 443. Specifically, the flow channel width T of the intermediate region 443 is the normal width of the spiral passage 412. The flow channel width C at the upstream end and the flow channel width D at the downstream end of the first widened region 441 are larger than the flow channel width T of the intermediate region 443. The flow channel width E at the upstream end and the flow channel width F at the downstream end of the second widened region 442 are larger than the flow channel width T of the intermediate region 443. The flow channel width of the first widened region 441 is the axial distance between the flow channel forming walls 420 adjacent in the axial direction in the first widened region 441. The flow channel width of the second widened region 442 is the axial distance between the flow channel forming walls 420 adjacent in the axial direction in the second widened region 442. The flow channel width of the intermediate region 443 is the axial distance between the flow channel forming walls 420 adjacent in the axial direction in the intermediate region 443. The flow path forming walls 420 adjacent to each other in the axial direction in the intermediate region 443 are parallel to each other. Therefore, the flow path width of the intermediate region 443 is constant along the direction in which the intermediate region 443 extends.

[0023] The first widening region 441 is disposed at a position adjacent to the upstream end 412a of the spiral passage 412 in the circumferential direction of the rotary electric machine casing 22. The first widening region 441 is formed by portions of the spiral passage 412 where adjacent flow path forming walls 420 have different inclination angles. A first flow straightening partition 451 is disposed between the flow path forming walls 420 having different inclination angles.

[0024] The first widening region 441 has a first branching portion 461 that branches the refrigerant flow at the upstream end of the first flow straightening partition wall 451, and a first merging portion 471 that merges the refrigerant at the downstream end of the first flow straightening partition wall 451. The first merging portion 471 is the downstream end of the first widening region 441, and the flow path width of the spiral passage 412 decreases at the location of the first merging portion 471. The flow path forming wall 420 has a first inclined portion 421 that is inclined so as to decrease the flow path width of the spiral passage 412 at the location of the first merging portion 471. An inclination angle β of the first inclined portion 421 with respect to the circumferential direction of the rotary electric machine casing 22 is larger than an inclination angle α of a portion (intermediate forming wall 423) of the flow path forming wall 420 that forms the intermediate region 443.

[0025] The first widening region 441 is divided in the axial direction into two sub-flow passages 441a and 441b by the first flow straightening partition 451. One side of one of the sub-flow passages 441a in the flow passage width direction is defined by the first end-forming wall 431. As shown in FIG. 2 , the sub-flow passage 441a and the upstream end 412a of the spiral passage 412 are arranged on the same circumference about the axis AX. The downstream side of the first flow straightening partition 451 extends toward the upstream end 412a of the spiral passage 412.

[0026] 3, the first flow rectifying partition wall 451 extends parallel to the first end-forming wall 431. The first flow rectifying partition wall 451 may be inclined with respect to the first end-forming wall 431. The first flow rectifying partition wall 451 is formed to have a length shorter than half the circumference of the rotary electric machine casing 22. The first flow rectifying partition wall 451 may be formed to have a length equal to or longer than half the circumference of the rotary electric machine casing 22.

[0027] The second widening region 442 is disposed at a position adjacent to the downstream end 412b of the spiral passage 412 in the circumferential direction of the rotary electric machine casing 22. The second widening region 442 is formed by portions of the spiral passage 412 where adjacent flow path forming walls 420 have different inclination angles. A second flow straightening partition 452 is disposed between the flow path forming walls 420 having different inclination angles.

[0028] The second widening region 442 has a second branching portion 462 that branches the refrigerant flow at the upstream end of the second flow straightening partition wall 452, and a second merging portion 472 that merges the refrigerant at the downstream end of the second flow straightening partition wall 452. The second branching portion 462 is the upstream end of the second widening region 442, and the flow path width of the spiral passage 412 is expanded at the location of the second branching portion 462. The flow path forming wall 420 has a second inclined portion 422 that is inclined so as to expand the flow path width of the spiral passage 412 at the location of the second branching portion 462. The inclination angle γ of the second inclined portion 422 with respect to the circumferential direction of the rotary electric machine casing 22 is larger than the inclination angle α of the intermediate forming wall 423.

[0029] The second flow straightening partition 452 divides the second widening region 442 in the axial direction into two sub-flow paths 442a and 442b. One side of one of the sub-flow paths 442b in the flow path width direction is defined by the second end-forming wall 432. As shown in FIG. 2 , the sub-flow path 442b and the downstream end 412b of the spiral passage 412 are arranged on the same circumference about the axis AX. The upstream side of the second flow straightening partition 452 extends toward the downstream end 412b of the spiral passage 412.

[0030] As shown in FIG. 3 , the second flow rectifying partition wall 452 extends parallel to the second end-forming wall 432. The second flow rectifying partition wall 452 may be inclined with respect to the second end-forming wall 432. The second flow rectifying partition wall 452 is formed to have a length shorter than half the circumference of the rotary electric machine casing 22. The extension length L2 of the second flow rectifying partition wall 452 is shorter than the extension length L1 of the first flow rectifying partition wall 451. The extension length L2 of the second flow rectifying partition wall 452 may be the same as the extension length L1 of the first flow rectifying partition wall 451 or may be longer than the extension length L1 of the first flow rectifying partition wall 451. The second flow rectifying partition wall 452 may be formed to have a length equal to or longer than half the circumference of the rotary electric machine casing 22. In other words, the shape (length, thickness, etc.) of the first flow straightening partition 451 and the second flow straightening partition 452 can be changed as appropriate, and the flow of the refrigerant can be adjusted by changing the flow path cross-sectional area in the first widening region 441 and the second widening region 442, respectively.

[0031] The discharge passage 413 communicates with the downstream end 412b of the spiral passage 412. The discharge passage 413 discharges the refrigerant that has passed through the spiral passage 412 from the rotating electric machine casing 22. The discharge passage 413 is an axial hole that penetrates an end wall portion (ceiling portion 32) that constitutes one end of the rotating electric machine casing 22 in an in-use state in the axial direction of the rotating electric machine 12. Note that the discharge passage 413 may also be a tangential hole that penetrates an outer periphery of the rotating electric machine casing 22 in a tangential direction.

[0032] As shown in Fig. 1, the transmission 14 is fixed to one end (ceiling portion 32) of the rotating electric machine 12. In this embodiment, the transmission 14 is configured as a planetary gear device. In this embodiment, the transmission 14 is arranged coaxially with the rotating electric machine 12. The transmission 14 has a sun gear 141 fixed to one end (upper end) of the shaft 16 of the rotating electric machine 12, and a plurality of planetary gears 142 that mesh with the sun gear 141.

[0033] The transmission 14 further includes a carrier 143 that supports a plurality of planetary gears 142, an output shaft 144 fixed to the carrier 143, and an internal gear 145 that meshes with the plurality of planetary gears 142. The output shaft 144 is disposed coaxially with the shaft 16. A load (for example, the propeller 106 shown in FIG. 4) is connected to the output shaft 144. The transmission 14 further includes a transmission casing 50 that houses the sun gear 141, the planetary gears 142, the carrier 143, the output shaft 144, and the internal gear 145. The internal gear 145 is formed on the inner circumferential surface of the transmission casing 50. Note that the configuration of the transmission 14 is not limited to a planetary gear device, and other transmission mechanisms may be used.

[0034] Lubricating oil circulates inside the transmission 14. The transmission 14 has an oil reservoir 52 that stores the lubricating oil. The oil reservoir 52 is provided in the lower part of the transmission casing 50. The oil reservoir 52 is formed in an annular shape centered on the axis AX of the rotating electric machine 12. Although not shown in detail, a lubricating oil circulation mechanism is provided inside the transmission casing 50 that collects the lubricating oil from the oil reservoir 52 and injects (sprays) the lubricating oil from above the gear train (sun gear 141, planetary gears 142, and internal gear 145). The pump that collects the lubricating oil from the oil reservoir 52 can be, for example, a cam-type pump that is mechanically linked to the rotation of the shaft 16.

[0035] The cooling structure 15 further includes a second cooling passage 42 that cools the transmission 14. The first cooling passage 41 and the second cooling passage 42 are connected to each other, and a common refrigerant flows through the first cooling passage 41 and the second cooling passage 42. The transmission casing 50 includes a communication passage (not shown) that connects the first cooling passage 41 and the second cooling passage 42. The first cooling passage 41 and the second cooling passage 42 are arranged in series. In this embodiment, the first cooling passage 41 is arranged upstream of the second cooling passage 42. Specifically, the second cooling passage 42 is formed by a gap provided between the rotating electric machine casing 22 and the transmission casing 50.

[0036] The second cooling passage 42 is formed to surround the axis AX of the rotating electric machine 12. The second cooling passage 42 is formed along the oil reservoir 52. A groove 54 surrounding the axis AX is formed in the upper surface of the ceiling portion 32 of the rotating electric machine casing 22. The second cooling passage 42 is formed by this groove 54 and the lower surface of the transmission casing 50. The lower surface of the bottom wall 521 of the oil reservoir 52 is part of the lower surface of the transmission casing 50. Therefore, the second cooling passage 42 is formed by the lower surface of the bottom wall 521 of the oil reservoir 52 and the groove 54. The transmission casing 50 further has an outlet passage (not shown) that discharges the refrigerant that has passed through the second cooling passage 42 from the transmission casing 50. The outlet passage opens at an outlet port 64 provided in the transmission casing 50.

[0037] The drive unit 10 further includes an inner seal member 56 and an outer seal member 58 arranged between the rotating electric machine 12 and the transmission 14. The inner seal member 56 is arranged between the rotating electric machine 12 and the transmission 14 inside the second cooling passage 42 that extends in an arc shape (C-shape). The outer seal member 58 is arranged between the rotating electric machine 12 and the transmission 14 outside the second cooling passage 42. The inner seal member 56 and the outer seal member 58 are sandwiched between the rotating electric machine casing 22 and the transmission casing 50. The inner seal member 56 and the outer seal member 58 are arranged concentrically with respect to the axis AX.

[0038] A recovery line 613 of the refrigerant circulation device 60 is connected to the outlet port 64. The refrigerant is introduced into a supply unit 610 of the refrigerant circulation device 60 via the recovery line 613. Although not shown in detail, the supply unit 610 has, for example, a heat exchanger that cools the refrigerant, and a pump that feeds the refrigerant to the first cooling passage 41 of the cooling structure 15. Note that the pump can be of any drive type, such as a mechanically driven type or an electrically driven type.

[0039] A supply unit 610 of the refrigerant circulation device 60 supplies the refrigerant to the first cooling passage 41 via a supply line 612. The refrigerant passes through the inlet passage 411, spiral passage 412, and discharge passage 413 of the first cooling passage 41 in this order, and is then discharged from the rotating electrical machine casing 22. As the refrigerant flows through the spiral passage 412, the casing 22 is cooled by the refrigerant.

[0040] Specifically, as shown in FIG. 3 , the refrigerant is introduced into the spiral passage 412 through the inlet passage 411. The refrigerant is diverted into sub-flow paths 441a and 441b at a first branching portion 461 of the first widening region 441. The diverged refrigerant flows merge at a first merging portion 471 and flow toward the intermediate region 443. The refrigerant flows through the intermediate region 443 and into the second widening region 442. The refrigerant is diverted into sub-flow paths 442a and 442b at a second branching portion 462 of the second widening region 442. The diverged refrigerant flows merge at a second merging portion 472 and reach the discharge passage 413.

[0041] 1, the refrigerant flows from the discharge passage 413 of the first cooling passage 41 into the second cooling passage 42 via a communication passage (not shown). As the refrigerant flows through the second cooling passage 42, the refrigerant cools the transmission casing 50. The refrigerant is discharged from the second cooling passage 42 to the outside of the transmission casing 50 via the outlet port 64. The refrigerant discharged from the transmission casing 50 is returned to the supply unit 610 via the recovery line 613 of the refrigerant circulation device 60.

[0042] 4, the drive unit 10 can be applied to a propeller device 100. The drive unit 10 can be used as a power source for other devices as well as the propeller device 100. The propeller device 100 includes the drive unit 10, a housing 104 that houses the drive unit 10, and a propeller 106 connected to the transmission 14 of the drive unit 10.

[0043] The propeller device 100 is used in, for example, a vertical take-off and landing aircraft. Therefore, the rotating electric machine 12 is arranged so that the axis AX of the rotating electric machine 12 faces in the vertical direction when the propeller device 100 is in use. The propeller device 100 may be configured so that the axis AX of the rotating electric machine 12 faces in the approximately horizontal direction when in use.

[0044] A fan 108 that generates airflow within the housing 104 is attached to the lower end of the shaft 16 of the rotating electric machine 12, and sends air to, for example, a heat exchanger (not shown) of the supply unit 610. The propeller 106 has a propeller shaft 110 connected to the output shaft 144 of the transmission 14, a hub 112 provided at the upper end of the propeller shaft 110, and a plurality of blades 114 that protrude radially outward from the hub 112. Note that the present invention can also be used in two-wheeled and four-wheeled vehicles, aircraft, ships, etc., by oriented so that the rotational axis of the output shaft 144 of the transmission 14 of the drive unit 10 is horizontal.

[0045] This embodiment has the following advantages.

[0046] 3, first flow straightening partition walls 451 are provided in the first widening region 441 of the spiral passage 412, and second flow straightening partition walls 452 are provided in the second widening region 442, which prevents the refrigerant flow from becoming uneven in the widened portion of the flow path and allows the refrigerant to spread throughout the entire flow path of the spiral passage 412. This allows the refrigerant to flow smoothly while expanding the cooling range, thereby improving cooling efficiency.

[0047] A first widening region 441 and a second widening region 442 are formed by portions of the spiral passage 412 where adjacent flow path forming walls 420 have different inclination angles, and a first flow straightening partition 451 and a second flow straightening partition 452 are arranged between the flow path forming walls 420 with different inclination angles. The first flow straightening partition 451 and the second flow straightening partition 452 disperse the bias in the flow caused by the increase in the flow path width, thereby making it possible to increase the area to be cooled.

[0048] The first widening region 441 and the second widening region 442 are provided at positions adjacent to the upstream end 412a and the downstream end 412b of the spiral passage 412 in the circumferential direction of the rotary electric machine casing 22. The first end-forming wall 431 and the second end-forming wall 432 extend parallel to the circumferential direction of the rotary electric machine casing 22, and the first flow straightening partition 451 and the second flow straightening partition 452 extend toward the upstream end 412a and the downstream end 412b of the spiral passage 412, respectively. As seen in conventional technology, if flow paths are not provided near the upstream end 412a and the downstream end 412b of the spiral passage 412 in order to avoid the upstream end 412a and the downstream end 412b, the cooling range is likely to be limited. In contrast, in this embodiment, flow paths are also provided near the upstream end 412a and the downstream end 412b, thereby expanding the area to be cooled.

[0049] The first flow rectifying partition wall 451 and the second flow rectifying partition wall 452 extend parallel to the first end-forming wall 431 and the second end-forming wall 432, respectively. By ensuring a constant gap between the first flow rectifying partition wall 451 and the first end-forming wall 431 and by ensuring a constant gap between the second flow rectifying partition wall 452 and the second end-forming wall 432, it is possible to suppress changes in the flow rate of the refrigerant and perform cooling efficiently.

[0050] The first flow rectifying partition walls 451 and the second flow rectifying partition walls 452 are formed to have a length shorter than half the circumference of the rotary electric machine casing 22. By minimizing the contact area between the refrigerant and the first flow rectifying partition walls 451 and minimizing the contact area between the refrigerant and the second flow rectifying partition walls 452, frictional resistance at the first flow rectifying partition walls 451 and the second flow rectifying partition walls 452 is suppressed, and an increase in pressure loss due to the first flow rectifying partition walls 451 and the second flow rectifying partition walls 452 can be suppressed.

[0051] The spiral passage 412 has a first widening region 441 provided at one end of the spiral passage 412 in the axial direction, and a second widening region 442 provided at the other end of the spiral passage 412 in the axial direction. A first flow straightening partition 451 is arranged in the first widening region 441, and a second flow straightening partition 452 is arranged in the second widening region 442. By expanding the cooling range on each side of the upstream end 412a and the downstream end 412b of the spiral passage 412, it is possible to further improve cooling efficiency.

[0052] One of the inlet passage 411 and the discharge passage 413 is a tangential hole that tangentially penetrates the outer periphery of the rotary electric machine casing 22, and the other of the inlet passage 411 and the discharge passage 413 is an axial hole that axially penetrates one end of the rotary electric machine casing 22. The extension length of the second flow straightening partition wall 452 is shorter than the extension length of the first flow straightening partition wall 451. By making the extension length of the second flow straightening partition wall 452 shorter than the extension length of the first flow straightening partition wall 451, it is possible to appropriately ensure the flow path width in the second widened region 442, which is likely to have a short circumferential length. This allows the refrigerant to flow smoothly, improving cooling efficiency.

[0053] The above embodiment can be summarized as follows.

[0054] The above embodiment is a rotating electric machine (12) including a casing (22) that houses a rotor (18) and a stator (20), the casing having a spiral passage (412) through which a liquid refrigerant flows, the casing having a flow path forming wall (420) that at least a portion of which extends spirally at a constant inclination angle between an upstream end (412a) and a downstream end (412b) of the spiral passage, and the spiral passage has a flow path forming wall (420) that is adjacent to the upstream end (412a) and the downstream end (412b) of the spiral passage, the flow path width of the flow path forming wall being equal to or larger than that of the other flow path forming wall in the axial direction of the casing. a widening region (441, 442) larger than a portion of the spiral passage, the widening region being formed on at least one end side of the spiral passage in the axial direction, straightening partition walls (451, 452) extending along the spiral passage being formed in the widening region, and the widening region having branching portions (461, 462) that branch the flow of the refrigerant by upstream ends of the straightening partition walls, and merging portions (471, 472) that merge the refrigerant by downstream ends of the straightening partition walls.

[0055] The provision of the flow-straightening partition walls in the widened region of the spiral passage prevents uneven refrigerant flow in the widened portion of the flow passage and allows the refrigerant to flow throughout the entire flow passage of the spiral passage, thereby expanding the cooling area and allowing the refrigerant to flow smoothly, thereby improving cooling efficiency.

[0056] The widened region is formed by a portion of the spiral passage where adjacent flow path forming walls have different inclination angles, and the flow straightening partition wall is disposed between the flow path forming walls having different inclination angles.

[0057] The area to be cooled can be increased by dispersing the bias in the flow of the coolant caused by the increase in the flow path width using the flow-straightening partition walls.

[0058] The widening region is provided at a position adjacent to the upstream end or the downstream end of the spiral passage in the circumferential direction of the casing, and the flow path forming wall has an end forming wall (431, 432) that forms at least one end of the spiral passage in the axial direction, the end forming wall extending parallel to the circumferential direction, and the flow straightening partition extending toward the upstream end or the downstream end of the spiral passage.

[0059] If the flow passages are not provided near the upstream or downstream end of the spiral passage in order to avoid the upstream or downstream end, the cooling range is likely to be limited. In contrast, by providing flow passages near the upstream or downstream end, the area to be cooled can be expanded.

[0060] The flow straightening partition wall extends parallel to the end forming wall.

[0061] By ensuring a constant distance between the flow-regulating partition wall and the end-forming wall, it is possible to suppress changes in the flow rate of the refrigerant and achieve efficient cooling.

[0062] The flow straightening partition wall is formed to have a length shorter than half the circumference of the casing.

[0063] By minimizing the contact area between the refrigerant and the flow-straightening partition walls, frictional resistance at the flow-straightening partition walls can be suppressed, and an increase in pressure loss due to the flow-straightening partition walls can be suppressed.

[0064] The widening region has a first widening region (441) provided on one end side of the spiral passage in the axial direction and a second widening region (442) provided on the other end side of the spiral passage in the axial direction, and the flow straightening partition has a first flow straightening partition (451) arranged in the first widening region and a second flow straightening partition (452) arranged in the second widening region.

[0065] By increasing the cooling area on each side of the upstream and downstream ends, the cooling efficiency can be further improved.

[0066] The casing has an inlet passage (411) connected to the upstream end of the spiral passage and a discharge passage (413) connected to the downstream end of the spiral passage, one of the inlet passage and the discharge passage is a tangential hole that tangentially penetrates an outer periphery of the casing, and the other of the inlet passage and the discharge passage is an axial hole that penetrates one end of the casing in the axial direction of the casing, the first widening region is provided at a position adjacent to one of the upstream end and the downstream end of the spiral passage that connects to the tangential hole, the second widening region is provided at a position adjacent to one of the upstream end and the downstream end of the spiral passage that connects to the axial hole, and the extension length of the second flow straightening partition wall is shorter than the extension length of the first flow straightening partition wall.

[0067] The second widening region, which is located adjacent to the upstream end or downstream end of the spiral passage that connects to the axial hole, tends to have a shorter circumferential length than the first widening region, which is located adjacent to the tangential hole. By making the extension length of the second flow straightening partition wall shorter than the extension length of the first flow straightening partition wall, it is possible to ensure an appropriate flow path width in the second widening region. This allows the refrigerant to flow smoothly and improves cooling efficiency.

[0068] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0069] 12... Rotating electric machine 22... Rotating electric machine casing (casing) 412...Spiral passage 420...Flow path forming wall 441...First widening region 442...Second widening region 451...First rectification partition 452...Second rectification partition 461...First branch section 462...Second branch section 471...First confluence section 472...Second confluence section

Claims

1. A rotating electric machine comprising a casing that houses a rotor and a stator, the casing having a spiral passage through which a liquid refrigerant flows, the casing has a flow path forming wall, at least a portion of which extends spirally at a constant inclination angle between the upstream end and the downstream end of the spiral passage; the spiral passage has widened regions in which the flow path widths of adjacent flow path forming walls in the axial direction of the casing are larger than other portions, a flow straightening partition wall extending along the spiral passage is formed in the widened region; the widened region includes a branching portion where the refrigerant flow branches at an upstream end of the flow-straightening partition wall, and a merging portion where the refrigerant flows merge at a downstream end of the flow-straightening partition wall, the confluence portion is a downstream end of the widening region, and the flow path width of the spiral passage is reduced at the confluence portion; the widened regions are provided at positions adjacent to the upstream end and the downstream end of the spiral passage in the circumferential direction of the casing.

2. 2. The rotating electric machine according to claim 1, the widened region is formed by a portion of the spiral passage where the inclination angles of the flow path forming walls adjacent to each other are different, The flow straightening partition wall is disposed between the flow path forming walls having different inclination angles.

3. 2. The rotating electric machine according to claim 1, the flow path forming wall has an end forming wall that forms at least one end of the spiral passage in the axial direction, the end-forming wall extends parallel to the circumferential direction, and the flow-straightening partition wall extends toward the upstream end or the downstream end of the spiral passage.

4. A rotating electric machine comprising a casing that houses a rotor and a stator, the casing having a spiral passage through which a liquid refrigerant flows, the casing has a flow path forming wall, at least a portion of which extends spirally at a constant inclination angle between the upstream end and the downstream end of the spiral passage; the spiral passage has widened regions in which the flow path widths of adjacent flow path forming walls in the axial direction of the casing are larger than other portions, the widened region is formed on at least one end side of the spiral passage in the axial direction, a flow straightening partition wall extending along the spiral passage is formed in the widened region; the widened region includes a branching portion where the refrigerant flow branches at an upstream end of the flow-straightening partition wall, and a merging portion where the refrigerant flows merge at a downstream end of the flow-straightening partition wall, the widened region is provided at a position adjacent to the upstream end or the downstream end of the spiral passage in the circumferential direction of the casing, the flow path forming wall has an end forming wall that forms at least one end of the spiral passage in the axial direction, the end-forming wall extends parallel to the circumferential direction, and the flow-straightening partition wall extends toward the upstream end or the downstream end of the spiral passage, The flow straightening partition wall extends parallel to the end forming wall.

5. 5. The rotating electric machine according to claim 4, The flow-straightening partition wall is formed to have a length shorter than half the circumference of the casing.

6. A rotating electric machine comprising a casing that houses a rotor and a stator, the casing having a spiral passage through which a liquid refrigerant flows, the casing has a flow path forming wall, at least a portion of which extends spirally at a constant inclination angle between the upstream end and the downstream end of the spiral passage; the spiral passage has widened regions in which the flow path widths of adjacent flow path forming walls in the axial direction of the casing are larger than other portions, the widened region is formed on at least one end side of the spiral passage in the axial direction, a flow straightening partition wall extending along the spiral passage is formed in the widened region; the widened region includes a branching portion where the refrigerant flow branches at an upstream end of the flow-straightening partition wall, and a merging portion where the refrigerant flows merge at a downstream end of the flow-straightening partition wall, the widening region has a first widening region provided on one end side of the spiral passage in the axial direction and a second widening region provided on the other end side of the spiral passage in the axial direction, the flow control partition walls include a first flow control partition wall disposed in the first widened region and a second flow control partition wall disposed in the second widened region.

7. 7. The rotating electric machine according to claim 6, the casing has an inlet passage connected to the upstream end of the spiral passage and a discharge passage connected to the downstream end of the spiral passage, one of the inlet passage and the discharge passage is a tangential hole that penetrates an outer periphery of the casing in a tangential direction, the other of the inlet passage and the discharge passage is an axial hole that penetrates one end of the casing in the axial direction of the casing, the first widening region is provided at a position adjacent to one of the upstream end and the downstream end of the spiral passage, the end connected to the tangential hole; the second widening region is provided at a position adjacent to one of the upstream end and the downstream end of the spiral passage that is connected to the axial hole, an extension length of the second flow straightening partition wall is shorter than an extension length of the first flow straightening partition wall.

Images