Motor unit and method for manufacturing the same

Abstract

The present invention provides a motor unit and a method for manufacturing a motor unit, wherein the motor unit comprises: a motor having a rotor that rotates about a motor axis and a stator located radially outside the rotor; a housing that houses the motor in a housing space provided therein; a refrigerant that is housed in the housing space; and a refrigerant piping through which the refrigerant passes. The stator comprises a stator core and a coil wound on the stator core. The coil comprises a pair of coil ends that protrude axially from the stator core. The refrigerant piping comprises a supply pipe that is bent circumferentially along the motor axis and axially opposed to the coil ends. A plurality of first refrigerant supply holes that are open axially toward the coil ends are provided on the supply pipe.

Description

Technical Field

[0001] The present invention relates to a motor unit and a method for manufacturing the motor unit. Background Art

[0002] With the recent rise in popularity of electric and hybrid vehicles, the development of motor units that drive these vehicles has progressed. These motor units sometimes supply refrigerant to the motor to cool it. Patent Document 1 describes a structure in which an annular tube is placed radially outward of the stator coil ends, and refrigerant is discharged from refrigerant supply holes positioned radially inward in the tube to cool the coil ends.

[0003] Patent Document 1: Chinese Patent No. 106411050

[0004] When the tube is arranged radially outward relative to the coil end, there is a problem that the housing needs to be enlarged radially outward to accommodate the tube. In addition, a complicated assembly process may be required to accommodate the tube inside the housing. Summary of the Invention

[0005] One aspect of the present invention has been made in view of the above-mentioned problems, and one object thereof is to provide a motor unit that can be miniaturized in the radial direction of the motor axis and a method for manufacturing the motor unit.

[0006] A motor unit according to one embodiment of the present invention comprises: a motor having a rotor that rotates about a motor axis and a stator located radially outside the rotor; a housing that accommodates the motor in a storage space provided therein; a refrigerant that is accommodated in the storage space; and a refrigerant piping through which the refrigerant passes. The stator comprises: a stator core; and a coil wound on the stator core. The coil comprises a pair of coil ends that protrude axially from the stator core. The refrigerant piping comprises a supply pipe that is bent circumferentially along the motor axis and axially opposed to the coil ends. The supply pipe is provided with a plurality of first refrigerant supply holes that are open axially toward the coil ends.

[0007] According to one aspect of the present invention, a motor unit that can be miniaturized in a radial direction of a motor axis and a method for manufacturing the motor unit are provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a conceptual diagram of a motor unit according to one embodiment.

[0009] Figure 2 This is a perspective view of an oil pipe according to one embodiment.

[0010] Figure 3 This is a perspective view of an oil pipe and a stator according to one embodiment.

[0011] Figure 4 It is a side view of the oil piping and the stator according to one embodiment.

[0012] Figure 5 is a side view of a motor unit according to one embodiment.

[0013] Description of labels

[0014] 1: Motor unit; 2: Motor; 3: Gear unit; 6: Housing; 10: Oil pipe (refrigerant pipe); 11: First supply pipe (supply pipe); 11a: First fixing portion; 12: Second supply pipe (supply pipe); 12a: Second fixing portion; 13: Connecting pipe; 13a: First axially extending portion; 13b: Second axially extending portion; 13c: Connecting portion; 14: Relay pipe; 18: Second oil supply hole (second refrigerant supply hole); 19: First oil supply hole (first refrigerant supply hole); 20 : Rotor; 30: Stator; 31: Coil; 31a, 31b: Coil ends; 31c: Connection terminal; 32: Stator core; 32a: Stator core body; 32b: Protrusion; 32ba: Upper protrusion; 61: Motor storage portion; 61a: End face; 61b: Cylindrical portion; 61c: Partition wall (bottom); 61d: Bottom face; 61g: Partition wall opening; 80: Storage space; 81: Motor chamber; 82: Gear chamber; 95: Discharge port; J2: Motor axis; O: Oil (refrigerant). DETAILED DESCRIPTION

[0015] Hereinafter, a motor unit according to an embodiment of the present invention will be described with reference to the accompanying drawings. The scope of the present invention is not limited to the following embodiment, and can be arbitrarily modified within the scope of the technical concept of the present invention.

[0016] In the following description, the vertical direction is defined and described based on the positional relationship when the motor unit 1 is mounted on a vehicle located on a horizontal road surface. In addition, in the accompanying drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction represents the vertical direction (i.e., the up and down direction), the +Z direction is the upper side (the opposite side of the gravity direction), and the -Z direction is the lower side (the gravity direction). The X-axis direction is a direction perpendicular to the Z-axis direction, indicating the front and rear direction of the vehicle on which the motor unit 1 is mounted. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, indicating the width direction (left and right direction) of the vehicle.

[0017] In the following description, unless otherwise specified, the direction parallel to the motor axis J2 of the motor 2 (the Y-axis direction) is referred to simply as the "axial direction," the -Y side is referred to simply as the "one axial direction," and the +Y side is referred to simply as the "other axial direction." Furthermore, the radial direction centered on the motor axis J2 is referred to simply as the "radial direction," and the circumferential direction centered on the motor axis J2, i.e., the direction around the motor axis J2, is referred to simply as the "circumferential direction."

[0018] Figure 1 This is a conceptual diagram of the motor unit 1 of this embodiment. Figure 1 The structure of each part is schematically shown, and the actual position relationship of each part is not limited to Figure 1 In particular, Figure 1 In the diagram, the up-down direction on the paper is not necessarily consistent with the direction of gravity.

[0019] The motor unit 1 is mounted on a vehicle using a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV), and is used as a power source for the vehicle.

[0020] The motor unit 1 includes a motor 2 , a gear portion 3 including a reduction gear 4 and a differential gear 5 , a housing 6 , oil (refrigerant) O, and an oil pipe (refrigerant pipe) 10 through which the oil O passes.

[0021] <Housing>

[0022] A housing space 80 is provided inside the housing 6 for accommodating the motor 2, the gear unit 3, the oil piping 10, and the oil O. The housing 6 holds the motor 2 and the gear unit 3 in the housing space 80. The housing space 80 is divided into a motor chamber 81 for accommodating the motor 2 and a gear chamber 82 for accommodating the gear unit 3. The housing 6 is made of, for example, aluminum die casting.

[0023] The housing 6 has a motor housing portion 61 in which a motor chamber 81 is provided. The motor housing portion 61 has a cylindrical portion 61b centered on the motor axis J2 and a partition wall (bottom) 61c covering the opening on one axial side (-Y side) of the cylindrical portion 61b. That is, the housing 6 has a cylindrical portion 61b and a partition wall (bottom) 61c. The cylindrical portion 61b and the partition wall 61c surround the motor chamber 81 from the radial outside and one axial side. In addition, the housing 6 has a closing portion 63 that is axially opposite to the partition wall 61c across the motor chamber 81. The closing portion 63 can be removed from the motor housing portion 61. During the assembly process, the operator stores the motor 2 in the motor chamber 81 while removing the closing portion 63 from the motor housing portion 61 and opening the opening of the motor housing portion 61.

[0024] The storage space 80 is divided into a motor chamber 81 and a gear chamber 82 by a partition wall 61c. A partition wall opening 61g is provided in the partition wall 61c. The partition wall opening 61g connects the motor chamber 81 and the gear chamber 82. The partition wall opening 61g allows the oil O accumulated in the lower area of ​​the motor chamber 81 to move to the gear chamber 82.

[0025] Motor

[0026] The motor 2 is housed in a motor chamber 81 of the housing 6. The motor 2 includes a rotor 20 and a stator 30 located radially outside the rotor 20. The motor 2 is an inner rotor type motor including the stator 30 and the rotor 20 rotatably disposed inside the stator 30.

[0027] The rotor 20 rotates when power is supplied to the stator 30 from a battery (not shown). The rotor 20 includes a shaft 21, a rotor core 24, and rotor magnets 23 (not shown). Specifically, the motor 2 includes the shaft 21, the rotor core 24, and the rotor magnets. The rotor 20 rotates about the motor axis J2. The torque of the rotor 20 is transmitted to the gear unit 3.

[0028] The shaft 21 extends about the motor axis J2, which extends in the vehicle width direction (first direction). The shaft 21 rotates about the motor axis J2. The shaft 21 is a hollow shaft having a hollow portion 22 therein. This hollow portion 22 has an inner circumferential surface extending along the motor axis J2. The shaft 21 extends across the motor chamber 81 and the gear chamber 82 of the housing 6. One end of the shaft 21 protrudes toward the gear chamber 82. The pinion 41 is fixed to the end of the shaft 21 that protrudes into the gear chamber 82.

[0029] The rotor core 24 is formed by laminating silicon steel sheets. The rotor core 24 is a cylindrical body extending in the axial direction. A plurality of rotor magnets (not shown) are fixed to the rotor core 24. The plurality of rotor magnets are arranged circumferentially with alternating magnetic poles.

[0030] The stator 30 surrounds the rotor 20 from the radial outside. The stator 30 includes a stator core 32, coils 31, and an insulator (not shown) sandwiched between the stator core 32 and the coils 31. The stator 30 is held by the housing 6. The stator core 32 includes a plurality of magnetic pole teeth (not shown) extending radially inward from the inner circumference of an annular yoke. Coil wire is wound between the magnetic pole teeth. The coil wire wound around the magnetic pole teeth constitutes the coil 31.

[0031] The coil 31 has a first coil end 31a and a second coil end 31b. The first coil end 31a protrudes toward one axial side of the stator core 32. The second coil end 31b protrudes toward the other axial side of the stator core 32. In other words, the coil 31 has a pair of coil ends 31a and 31b that protrude toward both axial sides of the stator core 32.

[0032] <Gear Department>

[0033] The gear unit 3 is connected to the motor 2 and transmits power from the motor 2. The gear unit 3 is housed in the gear chamber 82 of the housing 6. The gear unit 3 is connected to the shaft 21 on one side of the motor axis J2 in the axial direction. The gear unit 3 includes a speed reduction device 4 and a differential device 5.

[0034] The reduction gear 4 is connected to the rotor 20 of the motor 2. The reduction gear 4 includes a pinion 41, an intermediate shaft 45, an intermediate gear 42 fixed to the intermediate shaft 45, and a drive gear 43. The pinion 41 rotates along the shaft 21 about the motor axis J2. The intermediate shaft 45 extends along an intermediate axis J4 parallel to the motor axis J2. The intermediate gear 42 and the drive gear 43 are disposed on the outer circumference of the intermediate shaft 45. The intermediate gear 42 meshes with the pinion 41. The drive gear 43 meshes with the ring gear 51 of the differential 5.

[0035] The differential 5 is housed in the gear chamber 82. It is connected to the motor 2 via the reduction gear 4. The differential 5 absorbs the speed difference between the left and right wheels while transmitting equal torque to a pair of output shafts 55 during vehicle cornering. The differential 5 includes a ring gear 51. The ring gear 51 rotates about the differential axis J2, which is parallel to the motor axis J2. The torque output from the motor 2 is transmitted to the ring gear 51 via the reduction gear 4.

[0036] exist Figure 1 In the figure, the differential device 5 is depicted below the reduction gear 4, but in reality, they are arranged side by side in a substantially horizontal direction. Furthermore, a portion of the ring gear 51 of the differential device 5 is immersed in the oil O accumulated in the lower area of ​​the gear chamber 82. The arrangement and structure of the differential device 5 and reduction gear 4 in this embodiment are merely examples and may be modified to other structures.

[0037] Oil (refrigerant)

[0038] Oil O circulates within an oil passage 90 provided in the housing 6. Oil O is used to cool the motor 2. Furthermore, oil O is used to lubricate the reduction gear 4 and the differential gear 5. Oil O is stored in a lower region within the gear chamber 82 (hereinafter referred to as the oil reservoir P). To fulfill both the functions of lubricating oil and cooling oil, oil O is preferably a low-viscosity oil equivalent to automatic transmission fluid (ATF).

[0039] Oil circuit

[0040] The oil passage 90 is provided in the housing 6. The oil passage 90 is located within the housing 6, namely, within the housing space 80. The oil passage 90 spans the motor chamber 81 and the gear chamber 82 within the housing space 80. The oil passage 90 comprises a first oil passage 91 and a second oil passage 92. The first oil passage 91 originates at a point where the oil rises from the oil reservoir P toward the intermediate gear 42. The second oil passage 92 originates at a point where the oil is drawn up from the oil reservoir P by the pump 96.

[0041] (1st oil circuit)

[0042] A pre-filter box 93 is provided within the first oil passage 91. The pre-filter box 93 is located within the gear chamber 82. In the first oil passage 91, oil O is lifted from the oil reservoir P by the intermediate gear 42 and directed to the pre-filter box 93. Furthermore, a portion of the oil O lifted by the intermediate gear 42 is directed to the bearings supporting the various shafts within the gear chamber 82, thereby improving the lubricity of the bearings. Another portion of the oil O lifted by the intermediate gear 42 is injected from above into the various gears within the gear chamber 82, providing the gear tooth surfaces. Thus, the oil O improves the lubricity of the gear unit 3.

[0043] A portion of the oil O accumulated in the pre-filter box 93 is supplied to the hollow portion 22 of the shaft 21. Another portion of the oil O accumulated in the pre-filter box 93 is supplied to the bearing 57. The oil O supplied to the hollow portion 22 of the shaft 21 continuously disperses radially outward from the holes provided in the rotor 20, cooling the stator 30. The oil O that reaches the stator 30 drips downward while removing heat from the stator 30, accumulating in the lower area of ​​the motor chamber 81. The oil O accumulated in the lower area of ​​the motor chamber 81 moves to the gear chamber 82 through the partition wall opening 61g provided in the partition wall 61c.

[0044] (Oil circuit 2)

[0045] A pump 96, a cooler 97, and an oil pipe 10 are provided in the second oil passage 92. The pump 96 and the cooler 97 are fixed to the outer surface of the housing 6. On the other hand, the oil pipe 10 is arranged in the motor chamber 81 of the housing 6.

[0046] Pump 96 is an electrically driven electric pump. The amount of oil O supplied by pump 96 to motor 2 is appropriately controlled according to the driving state of motor 2. Therefore, when the temperature of motor 2 rises, such as when long-term driving or high output is required, the driving output of pump 96 increases, and the amount of oil O supplied to motor 2 increases.

[0047] The cooler 97 cools the oil O passing through the second oil passage 92. A cooling water pipe (not shown) for passing cooling water supplied from the radiator is provided inside the cooler 97. The oil O passing through the cooler 97 exchanges heat with the cooling water.

[0048] In the second oil passage 92, oil O is sucked up from the oil reservoir P by a pump 96, cooled by a cooler 97, and then guided to the oil piping 10. The path from the oil reservoir P to the pump 96, the path from the pump 96 to the cooler 97, and the path from the cooler 97 to the oil piping 10 are each formed by a hole penetrating the wall of the case 6.

[0049] As will be described later, the oil pipe 10 is provided with a plurality of oil supply holes for discharging the oil O. The oil O discharged from the oil pipe 10 is supplied to the motor 2. The oil O supplied to the motor 2 flows along the surface of the stator core 32 and the coil 31 while removing heat from the stator 30, thereby cooling the motor 2. Furthermore, the oil O flowing along the surface of the stator 30 drips downward and accumulates in the lower area of ​​the motor chamber 81. The oil O of the second oil passage 92 merges with the oil O of the first oil passage 91 in the lower area of ​​the motor chamber 81. The oil O accumulated in the lower area of ​​the motor chamber 81 moves to the lower area (i.e., the oil reservoir P) in the gear chamber 82 via the partition wall opening 61g.

[0050] Oil piping (refrigerant piping)

[0051] Next, the oil pipe 10 arranged in the second oil passage 92 will be described in more detail.

[0052] Figure 2 It is a perspective view of the oil pipe 10 . Figure 3 It is a perspective view of the oil pipe 10 and the stator 30 .

[0053] like Figure 2 and Figure 3 As shown, the oil pipe 10 includes a pair of tubular supply pipes 11 and 12 serving as flow paths for the oil O, a pair of connecting pipes 13, four radial pipes 15, a pair of relay pipes 14, and a first fixing portion 11a and a second fixing portion 12a fixed to the housing 6. To ensure sufficient rigidity, the oil pipe 10 is made of a metal material such as an aluminum alloy or an iron alloy.

[0054] Hereinafter, each part of the oil pipe 10 will be described in detail.

[0055] (Supply pipe)

[0056] The oil piping 10 includes a first supply pipe (supply pipe) 11 and a second supply pipe (supply pipe) 12 as a pair of supply pipes 11 and 12. The first supply pipe 11 is located on one axial side of the stator 30 and axially faces the first coil end 31a. The first supply pipe 11 is connected to one end of the connecting pipe 13 via a radial pipe 15. On the other hand, the second supply pipe 12 is located on the other axial side of the stator 30 and axially faces the second coil end 31b. The second supply pipe 12 is connected to the other end of the connecting pipe 13 via a radial pipe 15.

[0057] The first and second supply pipes 11, 12 are curved with a constant curvature along the circumference of the motor axis J2. In this embodiment, the first and second supply pipes 11, 12 form an arc shape centered on the motor axis J2. Both ends of the first and second supply pipes 11, 12 are located below the motor axis J2. Both ends of the first and second supply pipes 11, 12 are sealed.

[0058] A plurality of (17 in this embodiment) first oil supply holes (first refrigerant supply holes) 19 are provided on the first supply pipe 11 and the second supply pipe 12 along the circumferential direction of the motor axis J2. The plurality of first oil supply holes 19 are arranged at equal intervals along the circumferential direction. The first oil supply hole 19 of the first supply pipe 11 opens to the other axial side (+Y side). In addition, the first oil supply hole 19 of the second supply pipe 12 opens to one axial side (-Y side). That is, the first oil supply holes 19 of the first supply pipe 11 and the second supply pipe 12 open axially toward the opposing coil ends 31a and 31b, respectively.

[0059] Oil O is supplied to the oil pipe 10 at a constant pressure by a pump 96. The oil O supplied to the oil pipe 10 fills the interiors of the first supply pipe 11 and the second supply pipe 12 and is ejected axially from the first oil supply hole 19. The oil O ejected from the first oil supply hole 19 of the first supply pipe 11 is supplied to the first coil end 31a. Furthermore, the oil O ejected from the first oil supply hole 19 of the second supply pipe 12 is supplied to the second coil end 31b. This effectively cools the pair of coil ends 31a and 31b of the stator 30.

[0060] In the first and second supply pipes 11, 12, a plurality of first oil supply holes 19 are arranged circumferentially. According to this embodiment, compared to supplying oil only from above the coil ends, low-temperature oil O, cooled by the cooler 97, can be evenly supplied circumferentially around the coil ends 31a, 31b. This allows for uniform cooling around the coil ends 31a, 31b, reducing the formation of locally high-temperature areas and improving the reliability of motor 2 operation.

[0061] According to this embodiment, the first supply pipe 11 and the second supply pipe 12 are arranged axially opposite each other relative to the coil ends 31a and 31b. As a result, the first supply pipe 11 and the second supply pipe 12 are arranged inside the axial projection area of ​​the stator 30. As a result, the motor unit 1 can be miniaturized in the radial direction of the motor axis J2.

[0062] Figure 4 30 is a side view of the oil pipe 10 and the stator 30. Figure 4 In FIG, the housing 6 is schematically illustrated by a two-dot chain line.

[0063] like Figure 4 As shown, the cylindrical portion 61b of the housing 6 surrounds the stator 30 from the radial outside. The cylindrical portion 61b functions as a wall that surrounds the motor chamber 81 from the radial outside. The partition wall 61c is located on one axial side of the cylindrical portion 61b and functions as a bottom. Furthermore, the partition wall 61c functions as a wall that positions the motor chamber 81 on one axial side. Furthermore, the wall on the other axial side of the motor chamber 81 is formed by a closing portion 63 that covers the opening on the other axial side of the cylindrical portion 61b.

[0064] The first supply pipe 11 is axially arranged between the first coil end 31a and the partition wall 61c. In addition, the first supply pipe 11 is surrounded by the cylindrical portion 61b from the radial outside. According to this embodiment, since it is arranged on the inner side of the axial projection area of ​​the stator 30, even when the inner peripheral surface of the cylindrical portion 61b is brought into contact with the outer peripheral surface of the stator 30, no interference with the first supply pipe 11 occurs. As a result, the cylindrical portion 61b of the housing 6 can be miniaturized in the radial direction. In addition, during the assembly process, by inserting the first supply pipe 11 from the opening of the housing 6, it can be easily arranged inside the motor chamber 81, which can simplify the assembly process.

[0065] In this embodiment, the first oil supply holes 19 of the first supply pipe 11 and the second supply pipe 12 are open in the axial direction. Therefore, even when the first supply pipe 11 and the second supply pipe 12 are arranged inside the axial projection area of ​​the stator 30, the oil O ejected from the first oil supply holes 19 can be supplied to the coil ends 31a and 31b.

[0066] According to this embodiment, since the first oil supply hole 19 is open in the axial direction, the oil O is ejected axially from the first oil supply hole 19, supplied axially to the coil ends 31a, 31b, penetrates axially of the coil ends 31a, 31b, and then penetrates downward due to gravity.

[0067] In contrast, when oil is injected radially outward toward the coil end as in conventional structures, the oil that reaches the coil end penetrates radially and does not readily diffuse axially. Consequently, the oil O does not spread over a wide axial range of the coil end, increasing the axial heat distribution of the coil end.

[0068] According to this embodiment, since the first oil supply holes 19 are open in the axial direction toward the coil ends 31a and 31b, the oil O can penetrate a wide range of the coil ends 31a and 31b in the axial direction. As a result, the entire coil ends 31a and 31b can be effectively cooled.

[0069] like Figure 3As shown, coil 31 has three connection terminals 31c extending radially outward from the second coil end 31b. These three connection terminals 31c are formed by bundling the coil wires of coil 31 and providing crimp terminals at the ends. These three connection terminals 31c correspond to the U phase, V phase, and W phase, respectively. Phase-shifted AC currents are supplied to each of the three connection terminals 31c from an inverter (not shown).

[0070] The coil wires leading to the three connection terminals 31c are routed from the U-phase, V-phase, and W-phase coils 31, respectively. The outer circumference of the coil wires leading to the connection terminals 31c is covered with an insulating tube to prevent them from conducting with the coil wires of other phases. Therefore, the outer diameter of the second coil end 31b extending from the connection terminal 31c is generally larger than that of the first coil end 31a.

[0071] In this embodiment, the diameter of the second supply pipe 12 around the motor axis J2 is larger than the diameter of the first supply pipe 11 around the motor axis J2. The second supply pipe 12 is opposite the second coil end 31b and supplies oil O to the second coil end 31b. As described above, since the second coil end 31b is larger than the first coil end 31a, by making the diameter of the second supply pipe 12 around the motor axis J2 larger than that of the first supply pipe 11, oil O can be evenly supplied to the entire second coil end 31b. In addition, in this embodiment, the second supply pipe 12 is located axially on the opposite side of the partition wall 61c. That is, the second supply pipe 12 is arranged on the opening side of the housing 6, and even if the diameter around the motor axis J2 is larger than that of the first supply pipe 11 arranged on the partition wall 61c side, it is not likely to hinder assembly. That is, according to this embodiment, by arranging the second coil end 31b of the lead connection terminal 31c on the opening side of the housing 6, the second supply pipe 12 having a larger diameter around the motor axis J2 can be made the opening side, thereby facilitating the assembly process.

[0072] Figure 5 It is a side view of the motor unit 1 as viewed from the axial direction, showing a state in which the closing portion 63 of the housing 6 is opened.

[0073] like Figure 5 As shown in FIG. 1 , the plurality of first oil supply holes 19 provided in the first supply pipe 11 and the second supply pipe 12 are located above the partition wall opening 61 g.

[0074] As described above, the oil O that has cooled the motor 2 drips down the motor 2 and accumulates in the lower area of ​​the motor chamber 81. It then moves through the partition wall opening 61g to the gear chamber 82. The level of the oil O accumulated in the lower area of ​​the motor chamber 81 is approximately below the upper end of the partition wall opening 61g. Furthermore, a portion of the stator 30 is immersed in the oil O accumulated in the lower area of ​​the motor chamber 81 and is thereby cooled by the oil O.

[0075] According to this embodiment, the first oil supply holes 19 of the first and second supply pipes 11 and 12 are located above the partition wall opening 61g. Therefore, the first oil supply holes 19 are always located above the liquid level of the oil O. In the stator 30, areas below the liquid level of the oil O are cooled by the accumulated oil O, eliminating the need to supply oil from the first oil supply holes 19 located below the liquid level of the oil O. According to this embodiment, the first oil supply holes 19 are located above the liquid level of the oil O, allowing sufficient oil O to be supplied to areas of the stator 30 requiring cooling.

[0076] Furthermore, in this embodiment, since both ends of the first and second supply pipes 11, 12 are sealed, the oil O is ejected only from the first oil supply hole 19. Therefore, by shortening the length from the first oil supply hole 19 to the lower end of the first and second supply pipes 11, 12, the area immersed in the oil O can be reduced. As a result, the first and second supply pipes 11, 12 are prevented from obstructing the flow of the oil O flowing toward the partition wall opening 61g in the lower region of the motor chamber 81, thereby enabling smooth discharge of the oil O from the motor chamber 81 to the gear chamber 82.

[0077] (Radial Tube)

[0078] like Figure 2 and Figure 3 As shown, the radial tubes 15 extend straight in the radial direction. Two of the four radial tubes 15 connect the first supply tube 11 and the connecting tube 13, and the remaining two connect the second supply tube 12 and the connecting tube 13.

[0079] (Connecting pipe)

[0080] The connecting pipe 13 extends parallel to the axial direction. The connecting pipe 13 is connected to the end surface facing one axial side with the relay pipe 14. In this embodiment, the connecting pipe 13 and the relay pipe 14 are a single component. In addition, the end surface facing the other axial side of the connecting pipe 13 is closed.

[0081] The connecting pipe 13 passes through the side of the stator core 32. In the present embodiment, the connecting pipe 13 is located above the stator core 32. The connecting pipe 13 connects the first supply pipe 11 and the second supply pipe 12 via the radial pipe 15.

[0082] The connecting tube 13 is provided with a plurality of second oil supply holes (second refrigerant supply holes) 18 arranged axially. The second oil supply holes 18 open radially inward. Some of the plurality of second oil supply holes 18 radially oppose the outer circumferential surface of the stator core 32. The oil O discharged from the second oil supply holes 18 of the connecting tube 13 is supplied to the outer circumferential surface of the stator core 32 and flows along the outer circumferential surface of the stator core 32, thereby cooling the stator core 32.

[0083] Furthermore, a portion of the plurality of second oil supply holes 18 located near the axial ends of the connecting tube 13 opens above the coil ends 31a, 31b and radially faces the coil ends 31a, 31b. The oil O discharged from these second oil supply holes 18 cools the coil ends 31a, 31b.

[0084] The second oil supply hole 18 of the connecting pipe 13 is larger than the first oil supply hole 19 of the supply pipes 11 and 12. The second oil supply hole 18 has a diameter of, for example, 1.5 mm to 2 mm. On the other hand, the first oil supply hole 19 has a diameter of, for example, 1 mm to 1.5 mm.

[0085] To reduce the radial dimension of the motor unit 1, the connecting pipe 13 is preferably arranged as close as possible to the stator core 32. The outer peripheral surface of the stator core 32 facing the second oil supply hole 18 is prone to scattering when the oil O collides strongly.

[0086] According to this embodiment, by making the second oil supply hole 18 relatively large, the flow rate of the oil O discharged from the second oil supply hole 18 can be suppressed, thereby suppressing the scattering of the oil O on the outer peripheral surface of the stator core 32. As a result, the oil O flows along the outer peripheral surface of the stator core 32, and the stator core 32 can be effectively cooled.

[0087] On the other hand, the supply pipes 11 and 12 are preferably arranged as far away from the coil ends 31a and 31b as possible to ensure sufficient insulation distance from the coil ends 31a and 31b. In addition, the coil ends 31a and 31b opposite the first oil supply hole 19 are a collection of coil wires, so the oil O is not easily scattered.

[0088] According to this embodiment, by making the first oil supply hole 19 relatively small, the flow rate of the oil O discharged from the first oil supply hole 19 can be increased, and even when the pressure in the oil piping 10 is low, the oil O can fully reach the coil ends 31a and 31b.

[0089] Next, the relationship between the connecting pipe 13 and the stator core 32 will be described.

[0090] like Figure 3 As shown, the stator core 32 includes a stator core body 32a and a plurality (four in this embodiment) of protrusions 32b. The stator core body 32a includes a cylindrical core back 32d extending axially and a plurality of teeth 32e extending radially inward from the core back 32d. The teeth 32e are arranged at equal intervals along the entire circumference.

[0091] The protrusion 32b protrudes radially outward from the outer circumference of the stator core body 32a. The protrusion 32b is fixed to the housing 6. Multiple protrusions 32b are arranged at equal intervals along the circumference. The protrusion 32b extends axially. For example, the protrusion 32b extends from one axial end of the stator core body 32a to the other axial end of the stator core body 32a. The protrusion 32b is provided with a through-hole 32c extending axially through the protrusion 32b. Bolts that secure the stator 30 to the housing 6 pass through the through-hole 32c.

[0092] One of the multiple protrusions 32b protrudes upward from the stator core body 32a. Here, the upwardly protruding protrusion 32b is referred to as the upper protrusion 32ba. That is, the multiple protrusions 32b include the upper protrusion 32ba located above the stator core body 32a. The pair of connecting pipes 13 are arranged in a circumferential direction centered on the motor axis J2, sandwiching the upper protrusion 32ba between them.

[0093] According to this embodiment, the pair of connecting tubes 13 can be positioned so as not to interfere with the protrusion 32b and can be arranged radially close to the stator core body 32a. Therefore, the oil O can be easily supplied from the pair of connecting tubes 13 to the stator core body 32a, and the radial size of the motor unit 1 can be suppressed.

[0094] Furthermore, according to this embodiment, by disposing a pair of connecting pipes 13 across the upper protrusion 32ba, oil O can be supplied to both circumferential sides of the upper protrusion 32ba. The outer circumferential surface of the stator core 32 slopes downward from the upper protrusion 32ba toward both circumferential sides. Therefore, the oil O can be distributed over a wide area of ​​the outer circumferential surface of the stator core 32, enabling even cooling of the entire stator core 32.

[0095] The connecting pipe 13 includes a first axially extending portion 13a, a second axially extending portion 13b, and a connecting portion 13c. The first axially extending portion 13a, the second axially extending portion 13b, and the connecting portion 13c are tubular.

[0096] The first axially extending portion 13a extends axially from the first supply pipe 11 side toward the other side. The first supply pipe 11 is connected to one axial end of the first axially extending portion 13a via a radial pipe 15. The first axially extending portion 13a, the first supply pipe 11, and the radial pipe 15 sandwiched therebetween are previously joined by welding, adhesive bonding, or other means.

[0097] The second axially extending portion 13b extends axially to one side from the second supply pipe 12. The second supply pipe 12 is connected to the other axial end of the second axially extending portion 13b via the radial pipe 15. The second axially extending portion 13b, the second supply pipe 12, and the radial pipe 15 sandwiched therebetween are previously joined by welding, adhesive bonding, or other means.

[0098] The other axial end of the first axially extending portion 13a and the one axial end of the second axially extending portion 13b are opposed to each other. The connecting portion 13c fits into the outer shapes of the first axially extending portion 13a and the second axially extending portion 13b. Thus, the connecting portion 13c connects the first axially extending portion 13a and the second axially extending portion 13b.

[0099] According to this embodiment, the connecting pipe 13 is divided into the first axially extending portion 13a and the second axially extending portion 13b, which are connected to each other by the connecting portion 13c. Therefore, during the assembly process, they can be easily connected by being arranged in sequence in the axial direction, which can simplify the assembly process.

[0100] In this embodiment, the first axially extending portion 13a is longer than the second axially extending portion 13b. Therefore, the connecting portion 13c is axially offset from the center of the stator core 32 toward the opening side of the housing 6 (axially). Consequently, during the assembly process, the first axially extending portion 13a and the second axially extending portion 13b can be connected on the opening side of the housing 6, simplifying the assembly process.

[0101] (First fixing portion and second fixing portion)

[0102] like Figure 2 As shown, the first fixing portion 11a is connected to the first supply pipe 11 by welding or other joining means. Similarly, the second fixing portion 12a is connected to the second supply pipe 12 by welding or other joining means. In this embodiment, three first fixing portions 11a are connected to the first supply pipe 11, and three second fixing portions 12a are connected to the second supply pipe 12. The first fixing portions 11a and the second fixing portions 12a are plate-shaped. The first fixing portion 11a extends radially inward from the first supply pipe 11. On the other hand, the second fixing portion 12a extends radially outward from the second supply pipe 12.

[0103] The first fixing portion 11a and the second fixing portion 12a are provided with fixing holes 17 extending therethrough in the axial direction. Fixing screws 16 for fixing the first fixing portion 11a and the second fixing portion 12a to the housing 6 are inserted into the fixing holes 17 .

[0104] like Figure 4As shown, the first fixing portion 11a is fixed to the bottom surface 61d of the partition wall 61c facing the other axial side. The second fixing portion 12a is fixed to the end surface 61a of the cylindrical portion 61b facing the other axial side.

[0105] According to the present embodiment, the first supply pipe 11 is fixed to the housing 6 at the first fixing portion 11a, and the second supply pipe 12 is fixed to the housing 6 at the second fixing portion 12a. That is, the first supply pipe 11 and the second supply pipe 12 are each independently fixed to the housing 6. Therefore, the first supply pipe 11 and the second supply pipe 12 can be stably fixed to the housing 6, respectively. Furthermore, in the assembly process, the first supply pipe 11 and the second supply pipe 12 can be independently fixed to the housing. In the present embodiment, the stator 30 is axially arranged between the first supply pipe 11 and the second supply pipe 12. Even in such a case, the first supply pipe 11, the stator 30, and the second supply pipe 12 can be assembled to the housing 6 in sequence along the axial direction, which can simplify the assembly process.

[0106] According to this embodiment, the first fixing portion 11a fixed to the bottom surface 61d extends radially inward from the first supply pipe 11. Therefore, the cylindrical portion 61b of the housing 6 does not become radially larger. Furthermore, since the second fixing portion 12a extends radially outward, it can be stably fixed to the end surface 61a of the cylindrical portion 61b.

[0107] (Relay tube)

[0108] like Figure 4 As shown, the relay tube 14 extends axially. One end of the relay tube 14 is connected to an oil O discharge port 95 provided in the housing 6. The discharge port 95 is open axially and discharges the oil O toward the other axial side. The oil O flows through the pair of relay tubes 14 into the oil piping 10. Furthermore, the other end of the relay tube 14 is located at one axial end of the connecting tube 13 and is connected to the connection between the connecting tube 13 and the radial tube 15.

[0109] According to this embodiment, the relay tube 14 is connected to the end of the connecting tube 13 and extends coaxially with the connecting tube 13. Therefore, the oil O can flow smoothly from the relay tube 14 to the connecting tube 13. Furthermore, since the connecting tube 13 is connected to the first supply tube 11 and the second supply tube 12, the oil O can be smoothly filled and flowed into the oil piping 10. Furthermore, according to this embodiment, by inserting the relay tube 14 into the discharge port 95 from one axial side, the oil piping 10 can be connected to the flow path provided in the housing 6, simplifying the assembly process.

[0110] <Assembly Process>

[0111] Next, according to Figure 4Next, a method for manufacturing the motor unit 1 including a step of assembling the oil pipe 10 and the stator 30 to the housing 6 will be described.

[0112] The method for manufacturing the motor unit 1 of this embodiment includes the following steps: a first step of assembling the first supply pipe 11 to the housing 6; a second step of assembling the stator 30 to the housing 6; and a third step of assembling the second supply pipe to the housing 6. The first, second, and third steps are performed in this order.

[0113] (Step 1)

[0114] The first supply pipe 11 is pre-assembled by welding or other means to connect the radial pipe 15, the intermediate pipe 14, the first axially extending portion 13a, and the first fixing portion 11a. In the first step, the operator inserts the first supply pipe 11 into the motor housing 61 from the open side and secures it to the housing 6.

[0115] In the first step, the first supply pipe 11 is first inserted into the motor housing portion 61 of the housing 6 from the open side. An outlet 95 opening into the motor housing portion 61 is provided on the bottom surface 61d of the housing 6. The outlet 95 faces the same direction as the opening direction of the motor housing portion 61, that is, the other axial side. In the first step, the first supply pipe 11 is inserted into the motor housing portion 61, and the relay pipe 14 installed on the first supply pipe 11 is connected to the outlet. Thus, the first supply pipe 11 is temporarily fixed relative to the housing 6. In addition, the first fixing portion 11a installed on the first supply pipe 11 is formally fixed to the bottom surface 61d of the motor housing portion 61 using the fixing screw 16.

[0116] According to the first step of this embodiment, after connecting the relay pipe 14 to the discharge port 95, the first supply pipe 11 is fixed to the housing 6. Therefore, the first supply pipe 11 can be permanently fixed to the housing 6 while being temporarily fixed, which can simplify the assembly process.

[0117] (Step 2)

[0118] In the second step, the operator inserts the stator 30 into the motor housing 61 from the open side and secures it to the housing 6. Specifically, bolts are inserted into the through-holes from the axially opposite side toward the axially opposite side, securing the stator 30 to the housing. In the second step, the stator 30 is positioned within the motor housing 61 so that it faces the axially opposite side of the first supply pipe 11. This positions the first coil end 31a of the stator 30 axially opposite the first oil supply hole 19 of the first supply pipe 11.

[0119] According to the manufacturing method of this embodiment, in the first and second steps, the first supply pipe 11 and the stator 30 are sequentially inserted into the motor housing portion 61, which is open to the other axial side. Specifically, the first supply pipe 11 and the stator 30 are assembled in one direction relative to the housing 6. Therefore, the position of the housing 6 does not need to be changed during the assembly process, simplifying the assembly process.

[0120] According to this embodiment, the first supply pipe 11 is axially opposed to the first coil end 31a and is arranged inside the axial projection area of ​​the stator 30. Therefore, even when the cylindrical portion 61b is reduced in size in the radial direction, a simple assembly process can be adopted in which the first supply pipe 11 is housed from the open side of the motor housing portion 61.

[0121] Furthermore, when the supply pipe is arranged radially outside the coil end as in the conventional structure, the supply pipe protrudes outward from the axial projection of the stator. Therefore, if such an assembly process is used, the housing becomes larger in the radial direction.

[0122] Furthermore, in this embodiment, the first fixing portion 11a and the stator 30 are fixed to the bottom surface 61d facing the same direction as the opening of the motor housing portion 61. Therefore, the first supply tube 11 and the stator 30 can be fixed from the same direction as the insertion process, further simplifying the assembly process.

[0123] (Step 3)

[0124] The radial tube 15, the second axially extending portion 13b, and the second fixing portion 12a are previously connected to the second supply pipe 12 by welding or other means to form a single component. In the third step, the operator arranges the second supply pipe 12 opposite the other axial side of the stator 30 and fixes it to the housing 6.

[0125] In the third step, the second supply tube 12 is temporarily secured to the first supply tube 11 before being secured to the housing 6. This temporary securing is achieved by connecting the second axially extending portion 13b extending from the second supply tube 12 to the connecting portion 13c of the first axially extending portion 13a extending from the first supply tube 11. The inner diameter of the connecting portion 13c is approximately the same as the outer diameter of the second axially extending portion 13b. The connecting portion 13c is connected to the second axially extending portion 13b by pressing or lightly pressing the second axially extending portion 13b into the connecting portion 13c.

[0126] In addition, in this embodiment, the first axially extending portion 13a and the second axially extending portion 13b are connected via the connecting portion 13c, but other structures may be adopted. For example, an expanded diameter portion may be provided at the front end of the first axially extending portion 13a or the second axially extending portion 13b, and the first axially extending portion 13a and the second axially extending portion 13b may be directly connected at the expanded diameter portion.

[0127] The second supply pipe 12 is permanently fixed to the housing 6 using the fixing screws 16 while being temporarily fixed to the first supply pipe 11. The end surface 61a to which the second supply pipe 12 is fixed faces the other axial side, similarly to the bottom surface 61d.

[0128] According to the third step of this embodiment, after the first axially extending portion 13a and the second axially extending portion 13b are connected, the second supply pipe 12 is fixed to the housing 6. Therefore, the second supply pipe 12 can be permanently fixed to the housing 6 in a temporarily fixed state, which can simplify the assembly process.

[0129] According to the manufacturing method of this embodiment, in addition to the first supply pipe 11 and stator 30, the second supply pipe 12 is also assembled to the housing 6 from the same orientation. Therefore, there is no need to change the orientation of the housing 6, simplifying the assembly process. Furthermore, according to the manufacturing method of this embodiment, since the second supply pipe 12 is fixed in the same direction as the first supply pipe 11 and stator 30, the assembly process can be further simplified.

[0130] While the embodiments and modifications of the present invention have been described above, the various structures and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications to the structures may be made without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

Claims

1. A motor unit comprising: a motor having a rotor that rotates about a motor axis and a stator located radially outside the rotor; a housing for accommodating the motor in a receiving space provided therein; a refrigerant stored in the storage space; as well as a refrigerant pipe through which the refrigerant passes, The stator has: stator core; and a coil wound on the stator core, The coil has a pair of coil ends protruding from the stator core to both sides in the axial direction. The refrigerant pipe includes a supply pipe that is bent along the circumferential direction of the motor axis and faces the coil end in the axial direction. The supply pipe is provided with a plurality of first refrigerant supply holes which are open in the axial direction toward the coil end. The motor unit has a gear portion connected to the motor to transmit the power of the motor. The housing has a partition wall that divides the housing space into a motor chamber for housing the motor and a gear chamber for housing the gear unit. The partition wall is provided with a partition wall opening for communicating the motor chamber with the gear chamber. The supply pipe is in an arc shape with the motor axis as the center. Both ends of the supply pipe are located below the motor axis and are closed. The plurality of first refrigerant supply holes provided in the supply pipe are located above the partition wall opening.

2. The motor unit according to claim 1, wherein The refrigerant piping includes a first supply pipe and a second supply pipe as a pair of supply pipes. The first supply pipe is located on one axial side of the stator, and the second supply pipe is located on the other axial side of the stator.

3. The motor unit according to claim 2, wherein: The refrigerant piping has: a first fixing portion connected to the first supply pipe and fixed to the housing; and The second fixing portion is connected to the second supply pipe and is fixed to the housing.

4. The motor unit according to claim 3, wherein: The housing has: a cylindrical portion surrounding the stator from a radially outer side; and a bottom portion, which is located on one axial side of the cylindrical portion, The first fixing portion extends radially inward from the first supply pipe and is fixed to the bottom surface of the bottom portion facing the other axial side. The second fixing portion extends radially outward from the second supply pipe and is fixed to an end surface of the cylindrical portion facing the other axial side.

5. The motor unit according to any one of claims 2 to 4, wherein: The coil has a connection terminal extending from the coil end located on the other side of the stator core in the axial direction. The diameter of the second supply pipe around the motor axis is larger than the diameter of the first supply pipe around the motor axis.

6. The motor unit according to any one of claims 2 to 4, wherein: The refrigerant piping includes a connecting pipe that passes through a side portion of the stator core in the axial direction and connects the first supply pipe and the second supply pipe. The connecting pipe has: a first axially extending portion extending from the first supply pipe side to the other axial side; a second axially extending portion extending from the second supply pipe side toward one axial side; and A connecting portion connects the first axially extending portion and the second axially extending portion.

7. The motor unit according to claim 6, wherein: The stator core has: a stator core body; and a protrusion that protrudes radially outward from the outer peripheral surface of the stator core body and is fixed to the housing; The plurality of protrusions include an upper protrusion located on the upper side of the stator core body. The refrigerant piping includes a pair of connecting pipes arranged with the upper protrusion interposed therebetween in a circumferential direction centered on the motor axis. The pair of connecting pipes are respectively provided with a second refrigerant supply hole that opens radially inward.

8. The motor unit according to claim 6, wherein The shell is provided with a discharge port which opens in the axial direction and discharges the refrigerant. The refrigerant pipe has a relay pipe connected to the discharge port. The relay pipe is connected to an end portion of the connecting pipe and extends on the same axis as the connecting pipe.

9. The motor unit according to claim 6, wherein The connecting pipe is provided with a second refrigerant supply hole that opens radially inward. The second refrigerant supply hole is larger than the first refrigerant supply hole.

10. A method for manufacturing a motor unit according to claim 1, wherein: The manufacturing method of the motor unit includes the following steps: In a first step, a first supply pipe having a plurality of first refrigerant supply holes directed toward the other axial side and bent along the circumferential direction of the motor axis is inserted into the motor housing from the opening side and fixed to the housing. as well as In the second step, the stator is inserted into the motor housing portion from the opening side, arranged in the motor housing portion to face the other axial side of the first supply pipe, and fixed to the housing.

11. The method for manufacturing a motor unit according to claim 10, wherein: The housing is provided with a discharge port, A relay pipe is pre-connected to the first supply pipe. In the first step, after the junction pipe is connected to the discharge port, the first supply pipe is fixed to the housing.

12. The method for manufacturing a motor unit according to claim 10 or 11, wherein: The manufacturing method of the motor unit further includes the following third step: arranging a second supply pipe having a plurality of first refrigerant supply holes facing one axial side and bent along the circumferential direction of the motor axis to face the other axial side of the stator and fixing it to the housing.

13. The method for manufacturing a motor unit according to claim 12, wherein: The first supply pipe is pre-connected with a first axially extending portion extending from one side of the first supply pipe to the other side in the axial direction. A second axially extending portion extending from the second supply pipe to one axial side is pre-connected to the second supply pipe. In the third step, after the first axially extending portion and the second axially extending portion are coupled together, the second supply pipe is fixed to the housing.

Images