Flow path structure of coolant in a rotating machine

Abstract

The present invention provides a coolant flow path structure in a rotating machine, which can reduce the pressure loss of the coolant flowing in the flow path. Thus, smooth flow of the coolant can be ensured and the cooling efficiency can be improved. A coolant flow path structure is provided in a cylindrical frame (2) in a motor (1) for cooling the motor (1). The coolant flow path structure includes: a flow path main body (11) which is provided in the wall thickness portion (2a) of the frame (2) and extends while bending along the circumferential direction of the frame (2), and through which the coolant flows during cooling; and a bypass flow path (12) which is provided to extend along the circumferential direction of the frame (2) at one of the axial ends of the frame (2) and connects the front-side reverse flow path portions (15, 15) of the frame (2) in the flow path main body (11) to each other, and through which the cooling water flows during cooling. The flow path main body has a plurality of straight flow path portions (14) arranged in the circumferential direction of the frame (2) and a plurality of reverse flow path portions (15, 16) connected to the ends of the straight flow path portions.

Description

Technical Field

[0001] The present invention relates to various rotating machines such as motors and generators for driving electric vehicles, and a flow path structure for a coolant for cooling the rotating machine. Background Art

[0002] Conventionally, as a flow path structure of a cooling water path provided on the outer peripheral surface of a motor and through which cooling water flows, for example, the flow path structure described in Patent Document 1 is known. The motor has a cylindrical frame constituting its outer peripheral wall, and a water jacket having a cooling water path is provided so as to cover the outer peripheral surface of the frame. Specifically, the water jacket has: a cylindrical outer peripheral wall having an inner diameter larger than the outer diameter of the motor frame; and a plurality of fins disposed between the outer peripheral wall and the motor frame, extending a predetermined length in the axial direction of the motor and protruding radially of the motor. These fins are arranged at a predetermined interval in the circumferential direction of the frame in a state where one end portion in the length direction alternately approaches one side and the other side in the axial direction of the motor. Thereby, on the outer peripheral surface side of the motor frame, a cooling water path that extends while bending along the circumferential direction of the frame is formed.

[0003] In addition, on the water jacket, a cooling water inlet and a cooling water outlet are provided at one end portion in the axial direction of the motor in a state of being adjacent to each other in the circumferential direction of the water jacket. And, on the water jacket, a partition wall is provided between the cooling water inlet and the cooling water outlet, and the partition wall is formed substantially in the same manner as the above-described fins, extends in the entire axial direction of the motor, and separates the cooling water inlet side and the cooling water outlet side.

[0004] In a motor having a cooling water path configured as described above, when cooling water is sent to the cooling water inlet by a pump or the like, the cooling water flows along the cooling water path, that is, on the outer peripheral surface of the motor frame, while bending and traveling along the circumferential direction of the frame. Moreover, after the cooling water substantially circulates around the outer peripheral surface of the frame, it is discharged to the outside from the cooling water outlet. In this way, by causing the cooling water to flow on the outer peripheral surface of the motor frame, heat generation accompanying the rotation of the motor is suppressed by heat exchange with the cooling water, and the motor is cooled more efficiently than in the air-cooled type.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Utility Model Laid-Open No. 60-153653 ([ Figure 2 ) Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] In the electric machine having the above-described cooling water passage, the cooling water passage is configured to extend while bending along the circumferential direction of its frame. In this cooling water passage, there are portions where the flow path area of the cross section is large and portions where the flow path area is small mixedly present. That is, the flow path area of the above-described cooling water passage is uneven, becoming larger or smaller. Therefore, before the cooling water flows from the cooling water inlet to the cooling water outlet, the flow path area of the cooling water passage changes multiple times. At this time, pressure loss is likely to occur in the cooling water flowing through the cooling water passage. If such pressure loss becomes high, the smooth flow of the cooling water is hindered. As a result, the cooling efficiency of the electric machine is reduced.

[0010] The present invention is made to solve the above problems, and an object thereof is to provide a flow path structure of a coolant in a rotating machine, which can reduce the pressure loss of the coolant flowing in the flow path, thereby ensuring the smooth flow of the coolant and improving the cooling efficiency.

[0011] Means for Solving the Problems

[0012] In order to achieve the above object, the invention of Technical Solution 1 is a flow path structure of a coolant, which is provided on the cylindrical outer peripheral wall of a rotating machine for cooling the rotating machine, and is characterized in that the flow path structure of the coolant includes: a flow path main body, which is provided in the wall thickness portion of the outer peripheral wall along the circumferential direction of the outer peripheral wall while bending and extending, and through which the coolant flows during cooling; and a bypass flow path, which is provided to extend along the circumferential direction of the outer peripheral wall at one of the both end portions in the axial direction of the outer peripheral wall and connects the portions on the same end side of the outer peripheral wall in the flow path main body to each other, and through which the coolant flows during cooling. The flow path main body has: a plurality of straight flow path portions, which extend along the axial direction of the outer peripheral wall and are arranged at regular intervals in the circumferential direction of the outer peripheral wall for allowing the coolant to flow straight; and a plurality of reverse flow path portions, which are alternately connected to each other at the ends on the same side of the adjacent straight flow path portions in the circumferential direction of the outer peripheral wall on both end portions sides of the outer peripheral wall to reverse the flow direction of the coolant.

[0013] According to this structure, in the wall thickness portion of the cylindrical outer peripheral wall of the rotating machine, a flow path main body is provided that extends while bending along the circumferential direction of the outer peripheral wall. Specifically, the flow path main body that extends while bending along the circumferential direction of the outer peripheral wall is constituted by the above-described plurality of straight flow path portions and plurality of reverse flow path portions. Thus, during the cooling of the rotating machine, the coolant flowing in the flow path main body flows along the flow path main body, that is, through the plurality of straight flow path portions and plurality of reverse flow path portions, while bending and extending along the circumferential direction of the outer peripheral wall. As a result, the heat generated during the operation of the rotating machine is suppressed by heat exchange with the coolant, and the rotating machine can be cooled more efficiently than in the air-cooled type.

[0014] In addition, on the outer peripheral wall of the electric machine, a bypass flow path is provided at one of the both end portions in the axial direction thereof. The bypass flow path extends along the circumferential direction of the outer peripheral wall and connects the portions on the same end side of the outer peripheral wall in the flow path main body, that is, the reverse flow path portions adjacent to each other in the circumferential direction of the outer peripheral wall. In the flow path main body that extends while bending along the circumferential direction of the outer peripheral wall, on the end side of the outer peripheral wall, the flow direction of the coolant changes greatly and sharply. Therefore, there is a tendency for the pressure loss of the coolant to increase. Therefore, in the present invention, by providing the bypass flow path so as to connect the portions on the same end side of the outer peripheral wall in the flow path main body, that is, the reverse flow path portions to each other, when the coolant flows on the end side of the outer peripheral wall in the flow path main body, the coolant also flows in the bypass flow path. Thus, the pressure loss of the coolant can be reduced. Thereby, compared with the case where the coolant flows in the flow path main body without the bypass flow path as described above, the pressure loss of the coolant can be reduced. Thus, smooth flow of the coolant can be ensured, and the cooling efficiency of the rotating machine can be improved.

[0015] The invention of Technical Solution 2 is characterized in that, in the coolant flow path structure of the rotating machine described in Technical Solution 1, the bypass flow path has a plurality of bypass flow path portions, and the plurality of bypass flow path portions respectively connect the reverse flow path portions adjacent to each other in the circumferential direction of the outer peripheral wall.

[0016] According to this structure, the bypass flow path is constituted by a plurality of bypass flow path portions that respectively connect the reverse flow path portions adjacent to each other in the circumferential direction of the outer peripheral wall. By having a flow path structure including a flow path main body having the straight flow path portion and the reverse flow path portion configured as described above and a bypass flow path having a plurality of bypass flow path portions, the functions and effects of the above Technical Solution 1 can be more effectively achieved.

[0017] The invention of Technical Solution 3 is characterized in that, in the coolant flow path structure of the rotating machine described in Technical Solution 1, a coolant introduction portion for introducing the coolant and a coolant discharge portion for discharging the coolant are respectively provided in the specified straight flow path portions adjacent to each other.

[0018] According to this structure, when the coolant is sent to the coolant introduction portion, the coolant flows into the straight flow path portion provided with the coolant introduction portion. Then, starting from this straight flow path portion, the coolant travels along the flow path main body, that is, bends and travels along the circumferential direction of the outer peripheral wall and circulates around the outer peripheral wall once, and is discharged from the coolant discharge portion. In this way, by allowing the coolant to flow in the entire circumferential direction of the outer peripheral wall, the entire circumferential direction of the rotating machine can be efficiently cooled.

[0019] In the coolant flow path structure of the rotary machine described in Technical Solution 3, the invention of Technical Solution 4 is characterized in that it further includes a communication flow path that connects the reverse flow path portion connected to the end of the straight flow path portion provided with the coolant introduction portion and the reverse flow path portion connected to the end of the straight flow path portion provided with the coolant discharge portion.

[0020] According to this structure, the reverse flow path portion connected to the end of the straight flow path portion provided with the coolant introduction portion and the reverse flow path portion connected to the end of the straight flow path portion provided with the coolant discharge portion are connected by a communication flow path. Thus, through the multiple reverse flow path portions on the same end side of the outer peripheral wall in the flow path main body, the multiple bypass flow path portions of the bypass flow path, and the communication flow path, a flow path that continuously extends along the circumferential direction of the entire outer peripheral wall, that is, a flow path that surrounds the outer peripheral wall once, is formed. By providing such a flow path together with the flow path main body, it is possible to effectively reduce the pressure loss of the coolant that flows while bending along the flow path main body.

[0021] In the coolant flow path structure of the rotary machine described in Technical Solution 4, the invention of Technical Solution 5 is characterized in that the flow path area in the cross section of the communication flow path is set to be smaller than the flow path area in the cross section of each of the multiple bypass flow path portions.

[0022] According to this structure, since the flow path area in the cross section of the communication flow path is set to be smaller than the flow path area in the cross section of each bypass flow path portion, when the coolant flows, it is possible to suppress the direct flow (backflow) from the coolant introduction portion to the coolant discharge portion via this communication flow path.

[0023] In the coolant flow path structure of the rotary machine described in Technical Solution 2, the invention of Technical Solution 6 is characterized in that, among the multiple reverse flow path portions respectively arranged at both end portions of the outer peripheral wall, the flow path area in the cross section of the reverse flow path portion not connected to the bypass flow path portion is set to be larger than the flow path area in the cross section of the reverse flow path portion connected to the bypass flow path portion.

[0024] According to this structure, since the flow path area in the cross section of the reverse flow path portion not connected to the bypass flow path portion is set to be larger than the flow path area in the cross section of the reverse flow path portion connected to the bypass flow path portion, compared with the case where the flow path areas of all the reverse flow path portions are the same, as the entire flow path, it is possible to reduce the pressure loss of the coolant and ensure the smooth flow of the coolant. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a diagram of a motor showing the coolant flow path structure of an embodiment to which the present invention is applied. (a) is an external perspective view, and (b) is a perspective view showing the coolant flow path formed in the wall thickness portion of the frame.

[0026] Figure 2 It is a diagram showing the flow path of the cooling water shown in Figure 1 (b) in a state of being unfolded in the circumferential direction of the frame.

[0027] Figure 3 It is a diagram for explaining Figure 2 the flow of the cooling water in the flow path shown.

[0028] Figure 4 It is a diagram showing, as a comparative example of the motor with respect to Figure 1 the motor, a motor to which a flow path structure of cooling water in which a bypass flow path and a communication flow path are omitted is applied. (a) is an external perspective view, and (b) is a perspective view showing the flow path of the cooling water formed inside the wall thickness portion of the frame.

[0029] Figure 5 It is a diagram showing the state in which the flow path of the cooling water shown in Figure 4 (b) is unfolded in the circumferential direction of the frame.

[0030] Figure 6 It is a diagram for explaining Figure 5 the flow of the cooling water in the flow path shown. Detailed Embodiment

[0031] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. Figure 1 (a) shows the appearance of a motor to which a flow path structure of a coolant according to an embodiment of the present invention is applied. It should be noted that the motor 1 (rotating machine) is used, for example, as a drive motor for an electric vehicle.

[0032] As Figure 1 (a) shows, the motor 1 includes: a frame 2 (outer peripheral wall) formed in a cylindrical shape, two brackets 3 and 4 respectively joined to both end portions in the axial direction of the frame 2, a rotor (not shown) rotatably supported by the two brackets 3 and 4 via bearings (not shown), and a shaft 5 that rotates integrally with the rotor and protrudes forward of the bracket 3. In addition, a stator (not shown) is disposed between the inner peripheral surface of the frame 2 and the rotor.

[0033] It should be noted that, in the following description, Figure 1 the front side of (a), that is, the side where the shaft 5 protrudes, is defined as the front side, and on the other hand, the opposite side is defined as the rear side, and the above-mentioned brackets 3 and 4 are respectively referred to as "front bracket 3" and "rear bracket 4".

[0034] The frame 2 is manufactured by, for example, die-casting of aluminum, and is mostly formed into a cylindrical shape having a prescribed inner diameter, outer diameter, and a relatively thick wall thickness portion 2a. Further, at the front end portion and the rear end portion in the axial direction of the frame 2, a front flange 6 and a rear flange 7 that project a prescribed length in the radial direction are respectively provided. On the front flange 6, a plurality of (only 4 are illustrated in Figure 1 (a)) mounting holes 6a for bolt-fixing the front bracket 3 are formed. Similarly, on the rear flange 7, a plurality of (only 3 are illustrated in Figure 1 (a)) mounting holes 7a for bolt-fixing the rear bracket 4 are formed.

[0035] Further, inside the wall thickness portion 2a of the frame 2, a flow path 10 through which prescribed cooling water (coolant) for cooling the motor 1 flows is formed. The flow path 10 has a prescribed depth (a prescribed thickness in the radial direction of the frame 2), and is formed inside the wall thickness portion 2a in a state of being open to the front and rear of the frame 2. Moreover, the front bracket 3 and the rear bracket 4 are respectively installed in a watertight state on the front flange 6 and the rear flange 7 of the frame 2 via an unillustrated annular seal member, thereby constituting the flow path 10.

[0036] Figure 1 (b) shows the flow path 10 three-dimensionally, Figure 2 and shows the flow path 10 in a state of being developed in the circumferential direction of the frame 2. As shown in the two figures, the flow path 10 includes: a flow path main body 11 that extends while bending and traveling along the circumferential direction of the frame 2; a bypass flow path 12 that connects the adjacent front-side reverse flow path portions 15, 15 described later of the flow path main body 11 to each other; and a communication flow path 13 that connects the first front-side reverse flow path portion 15A and the fourth front-side reverse flow path portion 15D described later.

[0037] As Figure 1 (b) and Figure 2 show, the flow path main body 11 has: a plurality of straight flow path portions 14 that extend along the axial direction of the frame 2 (in Figure 2 it is the left-right direction), and are arranged at prescribed intervals from each other in the circumferential direction of the frame 2 (in Figure 2 it is the up-down direction); a plurality of front-side reverse flow path portions 15 that are connected to the front end portions of the adjacent straight flow path portions 14, 14 to each other and are used for reversing the flow direction of the cooling water; and a plurality of rear-side reverse flow path portions 16 that are connected to the rear end portions of the adjacent straight flow path portions 14, 14 to each other and are used for reversing the flow direction of the cooling water.

[0038] Specifically, as Figure 2As shown, the above-mentioned straight flow path portion 14 has eight straight flow path portions formed by the first to eighth straight flow path portions 14A to 14H. These first to eighth straight flow path portions 14A to 14H all have the same passage width with a specified size.

[0039] In addition, the above-mentioned front-side reverse flow path portion 15 has four front-side reverse flow path portions formed by the first to fourth front-side reverse flow path portions 15A to 15D that are respectively connected to each other at the front end portions ( Figure 2 the left end portions) of the first and second straight flow path portions 14A and 14B, the front end portions of the third and fourth straight flow path portions 14C and 14D, the front end portions of the fifth and sixth straight flow path portions 14E and 14F, and the front end portions of the seventh and eighth straight flow path portions 14G and 14H. These first to fourth front-side reverse flow path portions 15A to 15D all have the same passage width Wa with a specified size.

[0040] Moreover, the above-mentioned rear-side reverse flow path portion 16 has three rear-side reverse flow path portions formed by the first to third rear-side reverse flow path portions 16A to 16C that are respectively connected to each other at the rear end portions ( Figure 2 the right end portions) of the second and third straight flow path portions 14B and 14C, the rear end portions of the fourth and fifth straight flow path portions 14D and 14E, and the rear end portions of the sixth and seventh straight flow path portions 14F and 14G. These first to third rear-side reverse flow path portions 16A to 16C all have the same passage width Wb with a specified size, and this passage width Wb is set to be larger than the passage width Wa of the above-mentioned first to fourth front-side reverse flow path portions 15A to 15D. Therefore, the flow path area in the cross-section of the rear-side reverse flow path portion 16 is larger than the flow path area of the front-side reverse flow path portion 15.

[0041] The bypass flow path 12 is provided to extend along the circumferential direction of the frame 2 and connect the adjacent front-side reverse flow path portions 15, 15 to each other. Specifically, as Figure 2 shown, the bypass flow path 12 has three bypass flow path portions formed by the first to third bypass flow path portions 12A to 12C that respectively connect the first and second front-side reverse flow path portions 15A and 15B, the second and third front-side reverse flow path portions 15B and 15C, and the third and fourth front-side reverse flow path portions 15C and 15D to each other. These first to third bypass flow path portions 12A to 12C all have the same passage width Wc with a specified size.

[0042] As described above, the communication flow path 13 connects the first front-side reverse flow path portion 15A and the fourth front-side reverse flow path portion 15D. The communication flow path 13 has a passage width Wd of a specified size, and the passage width Wd is set to be smaller than the passage width Wc of the first to third bypass flow path portions 12A to 12C. Therefore, the flow path area in the cross section of the communication flow path 13 is smaller than the flow path areas of the first to third bypass flow path portions 12A to 12C.

[0043] As Figure 1 (a) shows, on the frame 2 having the flow path 10 configured as described above, a cooling water introduction portion 17 for introducing cooling water into the flow path 10 and a cooling water discharge portion 18 for discharging the cooling water from the flow path 10. These cooling water introduction portion 17 and cooling water discharge portion 18 are both formed in a substantially cylindrical shape. The introduction flow path portion 17a inside the cooling water introduction portion 17 is connected to a specified position of the first straight flow path portion 14A of the flow path main body 11. On the other hand, the discharge flow path portion 18a inside the cooling water discharge portion 18 is connected to a specified position of the eighth straight flow path portion 14H of the flow path main body 11.

[0044] Figure 3 Indicates the flow of the cooling water in the flow path 10. In order to cool the motor 1 during operation, when the cooling water is sent to the cooling water introduction portion 17 by a pump (not shown), the cooling water flows into the first straight flow path portion 14A of the flow path main body 11 via the introduction flow path portion 17a inside the cooling water introduction portion 17. The cooling water flows along the flow path main body 11 as shown by the thick-line arrow in Figure 3 . That is, the cooling water flowing into the flow path main body 11 flows while bending along the circumferential direction of the frame 2. Then, the cooling water reaching the eighth straight flow path portion 14H is discharged to the outside via the discharge flow path portion 18a inside the cooling water discharge portion 18.

[0045] In addition, as described above, when the cooling water flows in the flow path main body 11, as shown by the thin-line arrow in Figure 3 , a part of the cooling water flowing in the first to third front-side reverse flow path portions 15A to 15C immediately flows to the downstream front-side reverse flow path portion 15 through the first to third bypass flow path portions 12A to 12C.

[0046] And, in the communication flow path 13, similarly to the first to third bypass flow path portions 12A to 12C, a part of the cooling water flowing in the fourth front-side reverse flow path portion 15D flows through the communication flow path 13 to the first front-side reverse flow path portion 15A.

[0047] Here, as a comparative example with respect to the above-described motor 1, refer to the ones corresponding to the above Figures 1 to 3 respectively Figures 4 to 6, a simple description will be given to the flow path structure of the cooling water in the motor 1C with the bypass flow path 12 and the communication flow path 13 omitted from the flow path 10 according to the present embodiment. It should be noted that in the following description, the same reference numerals are assigned to the structural parts that are the same as those in the above-mentioned motor 1 and the flow path 10.

[0048] Figure 4 (a) shows the appearance of the motor 1C, Figure 4 (b) shows the flow path 10C formed in the frame 2 of the motor 1C. Additionally, Figure 5 the flow path 10C is shown in a state where it is developed in the circumferential direction of the frame 2. As Figure 4 and Figure 5 shown, compared with the flow path 10 of the present embodiment, the flow path 10C provided in the frame 2 of the motor 1C only has the flow path main body 11 and does not have the bypass flow path 12 and the communication flow path 13. Therefore, when the cooling water is sent to the flow path 10C, as Figure 6 shown, the cooling water only flows along the flow path main body 11 that bends and travels in the circumferential direction of the frame 2.

[0049] In contrast, in the flow path 10 of the present embodiment, when the motor 1 is cooled, as shown above Figure 3 shown, in addition to flowing in the flow path main body 11 of the flow path 10, the cooling water also flows in the bypass flow path 12 having the first to third bypass flow path portions 12A to 12C and the communication flow path 13.

[0050] Thus, according to the present embodiment, compared with the flow path 10C of the comparative example, the pressure loss of the cooling water flowing in the flow path 10 can be reduced. It should be noted that although detailed data is omitted, in the flow path 10 of the present embodiment and the flow path 10C of the comparative example, the results of the simulation analysis of the flow of the cooling water confirm that the flow velocity of the cooling water flowing in the first to third front side reverse flow path portions 15A to 15C of the flow path 10 connected via the first to third bypass flow path portions 12A to 12C is higher than that of the cooling water flowing in the first to third front side reverse flow path portions 15A to 15C of the flow path 10C (that is, the pressure loss of the flow path 10 is lower than that of the flow path 10C). Therefore, according to the present embodiment, the pressure loss of the cooling water can be reduced, thereby ensuring the smooth flow of the cooling water and improving the cooling efficiency of the motor 1.

[0051] In addition, in the flow path 10 of the present embodiment, since the flow path area in the cross section of the communication flow path 13 is set to be smaller than the flow path area of the bypass flow path 12 (the first to third bypass flow path portions 12A to 12C), when the cooling water flows, it is possible to suppress the direct flow (backflow) from the cooling water introduction portion 17 to the cooling water discharge portion 18 via the communication flow path 13. Further, in the flow path 10, since the flow path area in the cross section of the rear side reverse flow path portion 16 is set to be larger than the flow path area of the front side reverse flow path portion 15, as compared with the case where the flow path areas of all the reverse flow path portions 15 and 16 are the same, as the flow path 10 as a whole, it is possible to reduce the pressure loss of the cooling water and ensure smooth flow of the cooling water.

[0052] It should be noted that the present invention is not limited to the above-described embodiments and can be implemented in various ways. For example, in the present embodiment, the bypass flow path 12 and the communication flow path 13 are provided on the front end side of the frame 2 in the motor 1, but the present invention is not limited thereto, and the bypass flow path 12 and the communication flow path 13 may be provided on the rear end side of the frame 2, and the adjacent rear side reverse flow path portions 16, 16 may be connected to each other by the bypass flow path 12.

[0053] In addition, in the embodiment, the flow path structure of the cooling water in the motor 1 as a rotating machine has been described, but the present invention can be applied to various rotating machines (such as generators, etc.) that generate heat during operation. Further, in the embodiment, the motor 1 is cooled by flowing the cooling water in the flow path 10 of the motor 1, but other appropriate coolants (such as cooling oil, etc.) may be used instead of the above-mentioned cooling water.

[0054] In addition, the structures of the details of the flow path 10, the flow path main body 11, the bypass flow path 12, and the communication flow path 13 shown in the embodiment are merely examples and can be appropriately changed within the scope of the gist of the present invention. For example, in the flow path 10 of the present embodiment, as Figure 1 (b) and Figure 2 shown, with respect to all the rear side reverse flow path portions 16 (the first to third rear side reverse flow path portions 16A to 16C), at positions facing each other in the axial direction, three bypass flow paths 12 (the first to third bypass flow path portions 12A to 12C) are provided. However, due to manufacturing reasons or the like, a structure in which the bypass flow path 12 is reduced to one or two may also be adopted. Even in such a case, as compared with the above-described flow path 10C that does not have the bypass flow path 12 at all, an effect of reducing the pressure loss of the cooling water can be obtained.

[0055] Description of Reference Numerals

[0056] 1 Motor (Rotating Machine)

[0057] 1C Motor of Comparative Example

[0058] 2 Frame (outer peripheral wall)

[0059] 2a Wall thickness part of the frame

[0060] 3 Front bracket

[0061] 4 Rear bracket

[0062] 5 Shaft

[0063] 6 Front flange

[0064] 6a Mounting hole

[0065] 7 Rear flange

[0066] 7a Mounting hole

[0067] 10 Flow path

[0068] 10C Flow path of the comparative example

[0069] 11 Flow path main body

[0070] 12 Bypass flow path

[0071] 12A~12C First~Third bypass flow path parts

[0072] 13 Connecting flow path

[0073] 14 Straight flow path part

[0074] 14A~14H First~Eighth straight flow path parts

[0075] 15 Front-side reverse flow path part (reverse flow path part)

[0076] 15A~15D First~Fourth front-side reverse flow path parts

[0077] 16 Rear-side reverse flow path part (reverse flow path part)

[0078] 16A~16C First~Third rear-side reverse flow path parts

[0079] 17 Cooling water introduction part

[0080] 17a Introduction flow path part

[0081] 18 Cooling water discharge part

[0082] 18a Discharge flow path part

[0083] Wa Passage width of the front-side reverse flow path part

[0084] Wb Passage width of the rear-side reverse flow path part

[0085] Wc Passage width of the bypass flow path part

[0086] The path width of the Wd connected flow path.

Claims

1. A flow path structure for a coolant in a rotating machine, which is provided on the cylindrical outer peripheral wall of the rotating machine and is used to cool the rotating machine. Characterized in that: The flow path structure for the coolant in the rotating machine includes: A flow path main body, which is arranged in the wall thickness part of the outer peripheral wall and extends while bending and traveling along the circumferential direction of the outer peripheral wall. The flow path main body allows the coolant to flow during cooling; And A bypass flow path, which is arranged to extend along the circumferential direction of the outer peripheral wall at one of the two end parts in the axial direction of the outer peripheral wall, and connects the parts on the same end side of the outer peripheral wall in the flow path main body to each other. The bypass flow path is used to reduce the pressure loss of the coolant flowing on the end side of the outer peripheral wall in the flow path main body by allowing the coolant to flow during cooling. The flow path main body has: A plurality of straight flow path parts, which extend along the axial direction of the outer peripheral wall and are arranged at regular intervals in the circumferential direction of the outer peripheral wall, and are used to make the coolant flow straight; And A plurality of reverse flow path parts, which are alternately connected to each other at the end parts on the same side of the adjacent straight flow path parts in the circumferential direction of the outer peripheral wall at both end parts of the outer peripheral wall, so as to reverse the flow direction of the coolant. The bypass flow path has a plurality of bypass flow path parts, which respectively connect the adjacent reverse flow path parts to each other in the circumferential direction of the outer peripheral wall. A coolant inlet part for introducing the coolant and a coolant outlet part for discharging the coolant are respectively provided in the adjacent specified straight flow path parts. The flow path structure for the coolant in the rotating machine further includes a communication flow path, which connects the reverse flow path part connected to the end part of the straight flow path part provided with the coolant inlet part and the reverse flow path part connected to the end part of the straight flow path part provided with the coolant outlet part.

2. The flow path structure for the coolant in the rotating machine according to claim 1. Characterized in that: The flow path area in the cross section of the communication flow path is set to be smaller than the flow path area in the cross section of each of the plurality of bypass flow path parts.

3. The flow path structure for the coolant in the rotating machine according to claim 1. Characterized in that: Among the plurality of reverse flow path parts respectively arranged at both end parts of the outer peripheral wall, the flow path area in the cross section of the reverse flow path part not connected to the bypass flow path part is set to be larger than the flow path area in the cross section of the reverse flow path part connected to the bypass flow path part.

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