Motor unit

Abstract

To provide a motor unit which allows improvement in cooling performance.SOLUTION: A motor unit comprises: a motor; a housing which houses the motor; and a coolant path, provided inside the wall surface of the housing, through which a coolant circulates. The coolant path has: an inflow path which receives the coolant from the outside; a branch path, connected to the inflow path, into which the coolant flows from the inflow path; a first flow path, connected to the branch path, into which the coolant flows from the branch path; and a second flow path, connected to the branch path, into which the coolant flows from the branch path, and whose path length is shorter than that of the first flow path. The first flow path and the second flow path each have a structure in which a plurality of straight parts is serially connected by a plurality of bent parts. The cross section of each of the straight parts in the first flow path is larger than the cross section of each of the straight parts in the second flow path.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a motor unit including two refrigerant paths, a first path and a second path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When there is a difference in path length between the first path and the second path, a difference in pressure loss occurs between the two paths. As a result, the flow rate balance between the two paths may be disrupted, and an undesirable difference in cooling capacity may occur between the two paths.

Means for Solving the Problems

[0005] In a first aspect of the present technology, the motor unit includes a motor, a housing that houses the motor, and a refrigerant flow path provided in a wall surface of the housing and configured to allow refrigerant to flow. The refrigerant flow path includes an inflow path that receives refrigerant from the outside, a branch path connected to the inflow path and into which refrigerant flows from the inflow path, a first path connected to the branch path and into which refrigerant flows from the branch path, and a second path connected to the branch path and into which refrigerant flows from the branch path and has a shorter path length than the first path. The first path and the second path have a structure in which a plurality of straight portions are connected in series by a plurality of bent portions. The cross-sectional area of the straight portion of the first path is larger than the cross-sectional area of the straight portion of the second path.

[0006] According to the above configuration, the path length of the first flow path is longer than that of the second flow path. And the cross-sectional area of the straight part of the first flow path is made larger than the cross-sectional area of the straight part of the second flow path. Thereby, compared with the case where the cross-sectional area of the straight part of the first flow path is equal to the cross-sectional area of the straight part of the second flow path, the pressure loss in the first flow path can be reduced. And the more the pressure loss in the first flow path is reduced, the refrigerant flow rate distribution can be adjusted so that the flow rate of the refrigerant flowing into the first flow path increases. It becomes possible to appropriately set the balance of the cooling capacity between the first flow path and the second flow path.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0008] In the second aspect, in the above first aspect, the straight part of the first flow path and the straight part of the second flow path may extend in a direction parallel to the rotation axis of the motor.

[0009] In the third aspect, in the above first aspect, the refrigerant flow path may further include a discharge port that discharges the refrigerant from the first flow path and the second flow path. When viewed from the direction of the rotation axis of the motor, the positions of the inflow path and the discharge port may be different in the circumferential direction of the housing. The first flow path may be provided in a first region in the circumferential direction of the housing, which is a first region extending from the inflow path toward one side in the circumferential direction to the discharge port. The second flow path may be provided in a second region in the circumferential direction of the housing, which is a second region extending from the inflow path toward the other side in the circumferential direction to the discharge port.

[0010] According to the above configuration, the circumferential direction of the housing can be divided into a first region and a second region. Then, the first region can be cooled by the first flow path, and the second region can be cooled by the second flow path.

[0011] In the fourth aspect, in the above first aspect, the housing may include a body portion having a cylindrical shape around the rotation axis of the motor, a first cover that closes the first end face of the body portion on one side of the rotation axis, and a second cover that closes the second end face of the body portion on the other side of the rotation axis. The straight portions of the first flow path and the straight portions of the second flow path may be formed in the body portion. The bent portions of the first flow path and the bent portions of the second flow path may be formed in the first cover and the second cover.

[0012] According to the above configuration, by closing both end faces of the body portion with the first cover and the second cover, a structure in which a plurality of straight portions are connected in series by a plurality of bent portions can be realized.

[0013] In the fifth aspect, in the above fourth aspect, the body portion may be a casting.

[0014] In the sixth aspect, in the above first aspect, the cross-sectional area of the bent portion of the first flow path and the cross-sectional area of the bent portion of the second flow path may be equal.

[0015] According to the above configuration, the shape of the inner surface of the bent portion can be made common between the first flow path and the second flow path. This can simplify the processing of the bent portion and improve the assemblability of the first cover and the second cover.

Embodiment

[0016] (Configuration of Motor Unit 1) FIG. 1 shows a schematic cross-sectional view of a motor unit 1 according to this embodiment. In FIG. 1, the z-axis direction is the vertical direction, and the x-axis direction and the y-axis direction are the horizontal directions. Also, the x-axis direction is the direction in which the rotation shaft 11 extends. The coordinate relationship is the same in the subsequent figures.

[0017] The motor unit 1 is mounted on an electric vehicle. The electric vehicle includes a hybrid vehicle and an electric vehicle. In the electric vehicle, the motor 2 may be used as a driving motor that generates power for driving the vehicle, or may be used as a generator that generates electricity by regenerative braking force or surplus power of the engine. In the electric vehicle, the motor unit 1 is mounted such that the negative direction of the z-axis coincides with the gravitational direction.

[0018] The motor unit 1 mainly includes a motor 2, a housing 30, and a refrigerant flow path 40. The refrigerant in this embodiment is, for example, water. The motor 2 mainly includes a rotor 10 and a stator 20. The rotor 10 has a rotation shaft 11. The rotor 10 is fixed to the rotation shaft 11. The stator 20 has a stator core 21 and a coil 22. The stator core 21 is a substantially annular member made of laminated steel plates or the like. The stator core 21 also has a central axis CA. The central axis CA of the stator core 21 is common with the central axis of the rotation shaft 11. The stator core 21 has a cylindrical shape centered on the central axis CA.

[0019] The housing 30 is a member that houses the rotor 10 and the stator 20. The housing 30 includes a first cover 31, a second cover 32, and a body portion 33. The body portion 33 has a cylindrical shape around the rotation axis 11 of the motor 2. The central axis CA of the housing 30 is common with the central axis of the rotation axis 11. The manufacturing method and material of the body portion 33 can be appropriately selected. In this embodiment, the body portion 33 is a casting. The first cover 31 closes the first end face 33E1 of the body portion 33 on one side (+x direction side) of the rotation axis 11. The second cover 32 closes the second end face 33E2 of the body portion 33 on the other side (-x direction side) of the rotation axis 11. The rotation axis 11 is supported by the housing 30 via a bearing 34 and is rotatable.

[0020] (Configuration of the refrigerant flow path 40) The refrigerant flow path 40 will be described with reference to FIGS. 2 to 5. The refrigerant flow path 40 is provided in the wall surface of the housing 30 and is a flow path configured such that refrigerant flows through it. FIG. 2 is a plan view of the first end face 33E1 of the body portion 33 viewed from the +x direction side. In FIG. 2, for clarity, the positions of the inflow path 41, the branch path 42, the confluence path 45, and the discharge port 46 are indicated by a dashed-dotted line. FIG. 3 is a plan view of the joint surface of the first cover 31 viewed from the -x direction side. FIG. 4 is a developed view of the refrigerant flow path 40. Note that FIG. 4 is a schematic view and there are parts that are different from the actual dimensions.

[0021] The refrigerant flow path 40 includes an inlet path 41, a branch path 42, a first flow path 43, a second flow path 44, a confluence path 45, and an outlet 46. The inlet path 41, the branch path 42, the confluence path 45, and the outlet 46 are formed in the first cover 31. The inlet path 41 is a flow path for receiving refrigerant from the outside. The inlet path 41 is connected to the branch path 42. Refrigerant flows into the branch path 42 from the inlet path 41. The first flow path 43 and the second flow path 44 are connected to the branch path 42 (see FIG. 4, dotted arrows). Refrigerant flows into the first flow path 43 and the second flow path 44 from the branch path 42 (see FIG. 4, arrow Y1). The outlets of the first flow path 43 and the second flow path 44 are connected to the confluence path 45, and the outlet 46 is also connected to the confluence path 45. Refrigerant flows into the confluence path 45 from the first flow path 43 and the second flow path 44 (see FIG. 4, arrow Y2). The refrigerant that has flowed into the confluence path 45 is discharged to the outside from the outlet 46.

[0022] The first flow path 43 includes straight portions 43s1 - 43s6 and bent portions 43b1 - 43b5. The straight portions 43s1 - 43s6 are formed in the body portion 33 and extend parallel to each other in a direction (x-axis direction) parallel to the rotation axis 11. The ends of the straight portions 43s1 - 43s6 in the ±x directions are connected by the bent portions 43b1 - 43b5. The bent portions 43b2 and 43b4 that connect the ends on the +x direction side have a groove shape formed in the first cover 31. The bent portions 43b1, 43b3, and 43b5 that connect the ends on the -x direction side have a groove shape formed in the second cover 32. By fixing the first cover 31 and the second cover 32 to the body portion 33 with fastening members (not shown), the first flow path 43, which is a series of continuous paths, is formed (see FIG. 4, dotted arrows).

[0023] Similarly, the second flow path 44 includes straight portions 44s1 - 43s4 and bent portions 44b1 - 44b3. The straight portions 44s1 - 43s4 are formed in the body portion 33 and extend parallel to each other in a direction (x - axis direction) parallel to the rotation axis 11. The ±x - direction ends of the straight portions 44s1 - 43s4 are connected by the bent portions 44b1 - 44b3. The bent portion 44b2 that connects the +x - direction side ends has a groove shape formed in the first cover 31. The bent portions 44b1 and 44b3 that connect the -x - direction side ends have groove shapes formed in the second cover 32. By fixing the first cover 31 and the second cover 32 to the body portion 33 with fastening members (not shown), the second flow path 44, which is a series of continuous paths, is formed (see FIG. 4 and the dotted arrows).

[0024] The cross - sectional area of the straight portions 43s1 - 43s6 of the first flow path 43 is larger than the cross - sectional area of the straight portions 44s1 - 43s4 of the second flow path 44. Also, the grooves forming the bent portions 43b1 - 43b5 of the first flow path 43 and the grooves forming the bent portions 44b1 - 44b3 of the second flow path 44 all have the same shape. Therefore, the cross - sectional areas of the bent portions 43b1 - 43b5 and the bent portions 44b1 - 44b3 are all equal.

[0025] As shown in FIG. 2, when viewed from the rotation axis direction (x - direction), the positions of the inflow path 41 and the discharge port 46 are different in the circumferential direction of the housing 30. Here, the first region R1 and the second region R2 are defined. The first region R1 is a region in the circumferential direction of the housing 30 that extends from the inflow path 41 to the discharge port 46 on one side in the circumferential direction (the counter - clockwise side in FIG. 2). The second region R2 is a region in the circumferential direction of the housing 30 that extends from the inflow path 41 to the discharge port 46 on the other side in the circumferential direction (the clockwise side in FIG. 2). The first flow path 43 is provided in the first region R1. The second flow path 44 is provided in the second region R2. The second region R2 is smaller than the first region R1. Also, the path length of the second flow path 44 is shorter than that of the first flow path 43.

[0026] (Structure of the branch path 42) FIG. 5 shows an enlarged view of the enlarged area EA1 in FIG. 2. The enlarged area EA1 is a vicinity area of the branch path 42. The upper part of FIG. 5 is a plan view seen from the x-direction side. In the plan view of the upper part of FIG. 5, the positions of the branch path 42 and the inlet 42i are indicated by a one-dot chain line. The lower part of FIG. 5 is a cross-sectional view taken along line B-B of the plan view of the upper part of FIG. 5.

[0027] On the inner surface of the branch path 42, an inlet 42i, a first outlet 42d1, and a second outlet 42d2 are defined. The inlet 42i is an opening through which the refrigerant flows in from the inflow path 41. The first outlet 42d1 is an opening through which the refrigerant flows out to the straight portion 43s1 which is the inlet of the first flow path 43. The second outlet 42d2 is an opening through which the refrigerant flows out to the straight portion 44s1 which is the inlet of the second flow path 44. The area of the first outlet 42d1 is larger than the area of the second outlet 42d2. The first outlet 42d1 and the second outlet 42d2 are arranged adjacent to each other on the first end surface 33E1 of the body portion 33. The inlet 42i of the branch path 42 is arranged on the first cover 31 so as to face the first outlet 42d1 and the second outlet 42d2.

[0028] The first outlet 42d1 is an overlapping area between the opening area of the straight portion 43s1 and the opening area of the branch path 42 when viewed from the x-axis direction. The second outlet 42d2 is an overlapping area between the opening area of the straight portion 44s1 and the opening area of the branch path 42 when viewed from the x-axis direction. In the example of the plan view of the upper part of FIG. 5, the entire opening area of the straight portion 43s1 and the entire opening area of the straight portion 44s1 are included in the opening area of the branch path 42. Therefore, the opening area of the straight portion 43s1 corresponds to the first outlet 42d1, and the opening area of the straight portion 44s1 corresponds to the second outlet 42d2.

[0029] Here, as shown in the plan view of the upper part of FIG. 5, when viewed from the direction of the rotation axis 11 (x-direction), consider the center CP0 of the inlet 42i, the center CP1 of the first outlet 42d1, and the center CP2 of the second outlet 42d2. As shown in the cross-sectional view of the lower part of FIG. 5, the distance CD1 between the center CP0 and the center CP1 is smaller than the distance CD2 between the center CP0 and the center CP2.

[0030] Also, as shown in the cross-sectional view at the lower part of FIG. 5, consider the shortest distance SD1 from the inlet 42i to the first outlet 42d1 and the shortest distance SD2 from the inlet 42i to the second outlet 42d2. The shortest distance SD1 is smaller than the shortest distance SD2. Note that the shortest distance is the shortest distance in the path through which the refrigerant flows. For example, the minimum length of the virtual straight line when connecting the inlet 42i to the first outlet 42d1 with a virtual straight line corresponds to the shortest distance SD1.

[0031] (Effect) Describe the problem. If there is a difference in the path length between the first flow path 43 and the second flow path 44, a difference in the pressure loss amount will occur between the two flow paths. As a result, an undesirable difference in the cooling capacity between the two flow paths may occur, and the motor 2 may not be cooled uniformly. In addition, since it is necessary to increase the refrigerant pumping capacity according to the flow path with a large pressure loss, the pumping pump (not shown) may be unnecessarily enlarged. Therefore, in the technology of this specification, the cross-sectional area of the straight portions 43s1 - 43s6 of the first flow path 43 is made larger than the cross-sectional area of the straight portions 44s1 - 43s4 of the second flow path 44. Thereby, the pressure loss amount in the first flow path 43 can be reduced as compared with the case where the cross-sectional area of the straight portions 43s1 - 43s6 is equal to the cross-sectional area of the straight portions 44s1 - 43s4. Therefore, the flow rate of the refrigerant flowing into the first flow path 43 can be made larger than the flow rate of the refrigerant flowing into the second flow path 44. As a result, the flow rate distribution of the refrigerant can be adjusted so that the refrigerant flow rate in the first flow path 43 becomes larger. Since it is possible to appropriately set the balance of the cooling capacity between the first flow path 43 and the second flow path 44, it becomes possible to cool the motor 2 uniformly. In addition, since the difference in the pressure loss amount between the first flow path 43 and the second flow path 44 can be reduced, it becomes possible to suppress the unnecessary enlargement of the pumping pump.

[0032] For example, consider the case of reducing the pressure loss amount of the first flow path 43 having a longer flow path length by increasing the cross-sectional area of the bent portion. In this case, as shown in FIG. 4, a method of removing a plurality of regions CR located on the end faces of the partition walls partitioning between the straight portions by cutting is conceivable. However, this increases the man-hours and causes deterioration of the base material yield. On the other hand, in the technology of this specification, by appropriately setting the magnitude relationship between the cross-sectional areas of the straight portions 43s1-43s6 of the first flow path 43 and the cross-sectional areas of the straight portions 44s1-43s4 of the second flow path 44, the pressure loss amount of the first flow path 43 can be reduced. Since additional processes such as cutting of the partition wall are not required, it is possible to reduce the manufacturing cost and improve the yield.

[0033] In the technology of this specification, the cross-sectional areas of the straight portions 43s1-43s6 of the first flow path 43 are made larger than the cross-sectional areas of the straight portions 44s1-43s4 of the second flow path 44. Thereby, while maintaining the area ratio occupied by the flow paths between the first flow path 43 and the second flow path 44 equal with respect to the outer periphery of the housing 30, the arrangement density of the first flow path 43 can be reduced compared to the arrangement density of the second flow path 44. As a result, since the number of straight portions of the first flow path 43 can be reduced, the number of turns (i.e., the number of bent portions) can be reduced. Thereby, since the bending pipe resistance in the first flow path 43 can be reduced, the pressure loss amount in the first flow path 43 can be reduced.

[0034] (First Modification of Example 1) The positional relationship and area relationship among the inlet 42i, the first outlet 42d1, and the second outlet 42d2 can be changed in various ways. For example, in FIG. 5, the area of the first outlet 42d1 and the area of the second outlet 42d2 may be made equal. Also in this form, by having the relationship that the distance CD1 is smaller than the distance CD2 and the relationship that the shortest distance SD1 is smaller than the shortest distance SD2, the flow rate distribution of the refrigerant can be adjusted so that the refrigerant flow rate in the first flow path 43 becomes larger.

[0035] (Second Modification of Example 1) The cross-sectional areas of the straight portions 43s1 - 43s6 of the first flow path 43 are not necessarily constant and can be varied in various ways. For example, the straight portion 43s6 closer to the discharge port 46 may have a larger cross-sectional area than the straight portion 43s1 closer to the inflow path 41. Also, the cross-sectional area may be gradually increased as it progresses from the straight portion 43s1 to 43s6. To explain the effect. Since the refrigerant has a longer heat absorption time and its temperature rises as it approaches the discharge port 46, the cooling capacity decreases. Therefore, by increasing the cross-sectional area of the straight portion closer to the discharge port 46, the refrigerant flow velocity in the straight portion closer to the discharge port 46 can be made lower than the refrigerant flow velocity in the straight portion closer to the inflow path 41. Since the residence time of the refrigerant in the straight portion closer to the discharge port 46 can be increased, the cooling capacity in the straight portion closer to the discharge port 46 can be enhanced. As a result, it becomes possible to suppress the difference in cooling capacity between the straight portion closer to the discharge port 46 and the straight portion closer to the inflow path 41.

Example

[0036] In Example 2, the positional relationship and area relationship among the inlet 42i, the first outlet 42d1, and the second outlet 42d2 are different from those in Example 1. The same reference numerals are given to the contents common to Example 1, and the description thereof is omitted. Fig. 6 shows an enlarged view of the vicinity of the branch path 42 in Example 2. The range shown in Fig. 6 is the same as the range shown in Fig. 5 of Example 1.

[0037] In Example 2, the cross-sectional area of the straight portion 43s1 of the first flow path 43 and the cross-sectional area of the straight portion 44s1 of the second flow path 44 are the same. When the straight portion 43s1 is viewed from the x-axis direction, the entire opening region of the straight portion 43s1 is included in the opening region of the branch path 42. Therefore, the area AR1 of the first outlet 42d1 is equivalent to the cross-sectional area of the straight portion 43s1. On the other hand, when the straight portion 44s1 is viewed from the x-axis direction, only about half of the opening region of the straight portion 44s1 is included in the opening region of the branch path 42 (see the region IR). Therefore, the area AR2 of the second outlet 42d2 is smaller than the cross-sectional area of the straight portion 44s1 and also smaller than the area AR1 of the first outlet 42d1.

[0038] As shown in the plan view at the upper part of FIG. 6, consider the center CP0 of the inlet 42i, the center CP1 of the first outlet 42d1, and the center CP2 of the second outlet 42d2 when viewed from the direction of the rotation axis 11 (x direction). As shown in the cross-sectional view at the lower part of FIG. 6, the distance CD1a between the center CP0 and the center CP1 and the distance CD2a between the center CP0 and the center CP2 are equal.

[0039] Also, as shown in the cross-sectional view at the lower part of FIG. 6, consider the shortest distance SD1a from the inlet 42i to the first outlet 42d1 and the shortest distance SD2a from the inlet 42i to the second outlet 42d2. The shortest distance SD1a and the shortest distance SD2a are equal.

[0040] As described above, in the second embodiment, in the relationship among the inlet 42i, the first outlet 42d1, and the second outlet 42d2, the area AR2 of the second outlet 42d2 is made smaller than the area AR1 of the first outlet 42d1. Thereby, even when the distance CD1a and the distance CD2a are equal, or when the shortest distance SD1a and the shortest distance SD2a are equal, the pressure loss amount of the first flow path 43 can be reduced. That is, by appropriately setting the area relationship between the first outlet 42d1 and the second outlet 42d2, it becomes possible to adjust the flow rate distribution of the refrigerant so that the refrigerant flow rate in the first flow path 43 becomes larger.

[0041] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

[0042] (Other Modification Examples) The positional relationship among the inlet 42i, the first outlet 42d1, and the second outlet 42d2 is not limited to the form described in this specification and can take various forms. That is, in FIGS. 5 and 6, the case where the direction of the refrigerant flowing in from the inlet 42i and the directions in which the refrigerant flows out to the first outlet 42d1 and the second outlet 42d2 are all in the x direction was explained. However, it is not limited to this form. As shown in the example of FIG. 7, the inflow path 41 may extend in the z direction, and the direction of the refrigerant flowing in from the inlet 42i may be in the z direction. Even in this case, the distance CD1b between the center CP0 of the inlet 42i and the center CP1 of the first outlet 42d1 may be made smaller than the distance CD2b between the center CP0 and the center CP2 of the second outlet 42d2. Or, the shortest distance SD1b from the inlet 42i to the first outlet 42d1 may be made smaller than the shortest distance SD2b from the inlet 42i to the second outlet 42d2. Thereby, the flow rate distribution of the refrigerant can be adjusted so that the refrigerant flow rate in the first flow path 43 becomes larger.

[0043] The extending directions of the straight portions 43s1 - 43s6 and the straight portions 44s1 - 43s4 are not limited to the direction parallel to the rotation axis 11 (x-axis direction). For example, it may extend obliquely at an angle with respect to the rotation axis. Also, for example, it may be in a form that extends in the circumferential direction centered on the rotation axis 11.

[0044] In addition, the technical elements described in this specification or the drawings exhibit technical utility alone or in various combinations and are not limited to the combinations described in the claims at the time of filing. Also, the technology exemplified in this specification or the drawings can achieve multiple purposes simultaneously, and achieving one of those purposes itself has technical utility.

Description of Reference Numerals

[0045] 1: Motor unit 2: Motor 30: Housing 40: Refrigerant flow path 41: Inflow path 42: Branch path 42i: Inlet 42d1: First outlet 42d2: Second outlet 43: First flow path 44: Second flow path 43s1 - 43s6, 44s1 - 43s4: Straight sections 43b1 - 43b5, 44b1 - 44b3: Bending sections CD1, CD2: Distance SD1, SD2: Shortest distance

Claims

1. A motor, a housing that houses the motor, a refrigerant flow path provided in a wall surface of the housing and configured to allow a refrigerant to flow therethrough, comprising: the refrigerant flow path has an inflow path for receiving the refrigerant from the outside, is connected to the inflow path and is a branch path into which the refrigerant flows from the inflow path, is connected to the branch path and is a first flow path into which the refrigerant flows from the branch path, is connected to the branch path, into which the refrigerant flows from the branch path, and has a shorter path length than the first flow path, and is a second flow path, comprising: the first flow path and the second flow path have a structure in which a plurality of straight portions are connected in series by a plurality of bent portions, a cross-sectional area of the straight portion of the first flow path is larger than a cross-sectional area of the straight portion of the second flow path, a motor unit.

2. The motor unit according to claim 1, wherein the straight portion of the first flow path and the straight portion of the second flow path extend in a direction parallel to a rotation axis of the motor.

3. The refrigerant flow path further comprises an outlet for discharging the refrigerant from the first flow path and the second flow path, when viewed from a direction of a rotation axis of the motor, a position of the inflow path and a position of the outlet are different in a circumferential direction of the housing, the first flow path is provided in a first region in the circumferential direction of the housing, and is a first region that reaches the outlet from the inflow path toward one side in the circumferential direction, the second flow path is provided in a second region in the circumferential direction of the housing, and is a second region that reaches the outlet from the inflow path toward the other side in the circumferential direction, The motor unit according to claim 1.

4. The housing has a body portion having a cylindrical shape around a rotation axis of the motor, a first cover that closes a first end surface of the body portion on one side of the rotation axis, a second cover that closes a second end surface of the body portion on the other side of the rotation axis, comprising: the straight portion of the first flow path and the straight portion of the second flow path are formed in the body portion, the bent portion of the first flow path and the bent portion of the second flow path are formed in the first cover and the second cover, The motor unit according to claim 1.

5. The motor unit according to claim 4, wherein the body portion is a casting.

6. The motor unit according to claim 1, wherein a cross-sectional area of the bent portion of the first flow path is equal to a cross-sectional area of the bent portion of the second flow path.

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