Motor unit

Abstract

The invention provides a motor unit. The motor unit (6) drives an electric vehicle. The motor unit (6) includes an electric motor (20) and an inverter (10). The electric motor (20) generates a driving force and outputs the driving force from a drive shaft (27) provided on a first side in the axial direction. The inverter (10) is disposed adjacent to a second side in the axial direction of the electric motor (20), generates a drive current for driving the electric motor (20), and supplies the drive current to the electric motor (20).

Description

Technical Field

[0001] The invention relates primarily to a motor unit comprising a motor for driving a vehicle and a current regulating device. Background Art

[0002] Patent document 1 discloses an electric vehicle. The electric vehicle includes a drive motor and an inverter. The drive motor generates a driving force. The inverter is arranged at a position radially away from the drive motor. The inverter generates a driving current and supplies it to the drive motor. The drive motor transmits the generated driving force to the drive wheel after the transmission changes the speed.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-172457 Summary of the invention

[0004] Problem that the invention aims to solve

[0005] In the electric vehicle of Patent Document 1, the inverter is arranged at a position away from the drive motor in the radial direction outward. Therefore, the size of the structure including the drive motor and the inverter increases.

[0006] In view of the above, a main object of the present invention is to provide a compact motor unit including an electric motor for driving a vehicle and an inverter.

[0007] Solutions to the problem

[0008] The problems to be solved by the present invention are as described above. Next, means for solving the problems and their effects will be described.

[0009] According to the viewpoint of the present invention, a motor unit of the following structure is provided. That is, the motor unit drives a vehicle. The motor unit includes an electric motor and a current regulating device. The electric motor generates a driving force, and the driving force is output from a driving shaft arranged on a first side in an axial direction. The current regulating device is arranged adjacent to the axial direction of the electric motor, generates a driving current for driving the electric motor, and supplies the driving current to the electric motor.

[0010] Effects of the Invention

[0011] According to the present invention, it is possible to realize a motor unit including an electric motor for driving a vehicle and an inverter, the motor unit having a compact radial dimension. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a side view of an electric vehicle including the motor unit according to the first embodiment.

[0013] Figure 2 It is a perspective view of the motor unit according to the first embodiment.

[0014] Figure 3 It is a cross-sectional view of the motor unit according to the first embodiment.

[0015] Figure 4 It is a cross-sectional view of the motor unit after the first power transmission part of the first embodiment is changed to a second power transmission part.

[0016] Figure 5 It is a cross-sectional view of a motor unit according to a second embodiment.

[0017] Figure 6 It is a cross-sectional view of a motor unit according to a third embodiment.

[0018] Figure 7 It is a cross-sectional view of a motor unit according to a fourth embodiment. DETAILED DESCRIPTION

[0019] Next, the embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 The electric vehicle 1 including the motor unit 6 according to the first embodiment will be briefly described. Figure 1 It is a side view of the electric vehicle 1 .

[0020] In the following description, the left-right direction of the electric vehicle 1 is defined as the direction seen from the driver riding in the electric vehicle 1. Therefore, the front-back direction coincides with the vehicle length direction, and the left-right direction coincides with the vehicle width direction. In addition, the vertical direction and the up-down direction coincide with the height direction. Figure 1 As shown, the electric vehicle 1 includes a vehicle body 2 , front wheels 3 , and rear wheels 4 .

[0021] The vehicle body 2 includes a plurality of frames 2a that serve as the framework of the electric vehicle 1. Various components included in the electric vehicle 1 are mounted on these frames 2a. Specifically, a battery 5 and a motor unit 6 are mounted on the frames 2a.

[0022] The battery 5 stores electric power and supplies the stored electric power to the electric devices such as the motor unit 6. In the present embodiment, the battery 5 is charged by a charging device. Alternatively, the electric vehicle 1 may include an engine, and the battery 5 may be charged by the driving force of the engine. That is, the electric vehicle 1 may also be a hybrid vehicle including an engine and a motor.

[0023] As described below, the motor unit 6 includes an electric motor 20. The electric motor 20 generates a driving force using the electric power supplied from the battery 5. The electric motor 20 transmits the generated driving force to the rear wheels 4, which are driving wheels. In this way, the electric vehicle 1 can travel.

[0024] The electric vehicle 1 further includes a seat 7 and a steering handle 8. The driver sits on the seat 7, places his feet on the pedals on the side of the vehicle body 2, and operates the steering handle 8 by hand. The driver operates the steering handle 8 to change the direction of the steering wheel, i.e., the front wheel. In this way, the driving direction of the electric vehicle 1 can be changed. In addition, in the present embodiment, since the driver sits astride the seat 7, the electric vehicle 1 is a straddle-type vehicle. In addition, the electric vehicle 1 is a tilting type vehicle that tilts the vehicle body 2 toward the center of rotation relative to the road surface when turning.

[0025] The electric vehicle 1 of the present embodiment is a motorcycle having one front wheel 3 and one rear wheel 4. However, the electric vehicle 1 is not limited to a motorcycle, and the front wheels 3 may be two and the rear wheels 4 may be two. In other words, the number of wheels included in the electric vehicle 1 may be any one of 2, 3 or 4. Furthermore, the electric vehicle 1 may be either a vehicle for movement or a leisure vehicle for leisure. The motor unit 6 may also be used for a vehicle that does not mainly use wheels, such as a planing boat, an airplane, or other vehicles. The motor unit 6 may also be used for a mobile body that is not ridden by a person, such as an unmanned mobile body. The motor unit 6 may also be used for devices other than vehicles.

[0026] Secondly, refer to Figure 2 as well as Figure 3 The motor unit 6 is described in detail. In the following description, the axial direction of the electric motor 20 is simply referred to as the "axial direction", and the direction perpendicular to the axial direction is referred to as the "radial direction". In addition, the side in the axial direction from which the drive shaft 27 of the motor unit 6 protrudes is referred to as the first side, and the side opposite to the first side is referred to as the second side.

[0027] The motor unit 6 includes an inverter 10 and an electric motor 20. The inverter 10 and the electric motor 20 are connected to each other. In this way, the inverter 10 and the electric motor 20 can be treated as a whole. It should be noted that the drive shaft 27 of the electric motor 20 is connected to the first power transmission part 40, and the first power transmission part 40 is used to transmit the driving force toward the drive wheel, i.e., the rear wheel 4. The first power transmission part 40 is not a necessary component of the motor unit 6. Therefore, the first power transmission part 40 can also be arranged at a position far away from the inverter 10 and the electric motor 20. In the present embodiment, the first power transmission part 40 is realized by a sprocket 45 fixed to the drive shaft 27.

[0028] In the present embodiment, the inverter 10 is arranged adjacent to the second side of the electric motor 20. Specifically, the inverter 10 and the electric motor 20 are adjacent in a direction in which the thickness direction of the inverter 10 coincides with the axial direction of the electric motor 20. Furthermore, the inverter 10 is mounted on the second side of the electric motor 20, and the inverter 10 and the electric motor 20 are in contact. It should be noted that "adjacent" does not only refer to a state of being in contact, but also includes a state of being slightly separated. For example, when the inverter 10 and the electric motor 20 are mounted in a housing, sometimes the inverter 10 is slightly separated from the electric motor 20.

[0029] like Figure 3 As shown, the inverter 10 includes an inverter cover 11 , an inverter body 14 , terminals 15 , an insulating cover 16 , a first coolant passage 17 , and a supply port 18 .

[0030] The inverter cover 11 is a cylindrical component for accommodating the inverter body 14. In this specification, "cylindrical shape" means that it is substantially cylindrical as a whole. Therefore, the cylindrical shape is not only a strict cylindrical shape, but also includes a roughly cylindrical shape. For example, it can be a shape in which other shapes are added to the cylindrical shape, or it can be a shape in which a part of the cylindrical shape is removed. It should be noted that the inverter cover 11 is not limited to a cylindrical shape. For example, the inverter cover 11 can also be a rectangular parallelepiped shape. The inverter cover 11 is fixed to the inverter body 14 and covers at least a part of the inverter body 14. The fixing method of the inverter cover 11 and the inverter body 14 is, for example, bolts, and fixing methods other than bolts can also be used. The inverter cover 11 protects the inverter body 14 from impact or water. The inverter cover 11 of this embodiment is composed of a first inverter cover 12 and a second inverter cover 13. The first inverter cover 12 includes a fixing plate that fixes the inverter body 14. The second inverter cover 13 is a plate-shaped member disposed on the second side in the axial direction of the first inverter cover 12. However, the inverter cover 11 may be a single component. In the present embodiment, the cylindrical inverter cover 11 and the cylindrical motor cover 21 are formed coaxially.

[0031] The inverter cover 11 may be in a box shape that covers substantially the entire inverter body 14. Alternatively, the inverter cover 11 may be in a structure that covers only a portion of the inverter body 14.

[0032] The inverter 10 is connected to the electric motor 20. In the present embodiment, the inverter cover 11 and the electric motor 20 (more specifically, the motor cover 21) are connected. The structure for connecting the inverter cover 11 and the electric motor 20 is, for example, a bolt. More specifically, an insertion hole is formed in the inverter cover 11, and a screw hole is formed in the motor cover 21. The inverter cover 11 and the motor cover 21 are connected by aligning the insertion hole of the inverter cover 11 and the screw hole of the motor cover 21 and inserting the bolt and tightening it. In this way, the inverter 10 and the electric motor 20 are connected. It should be noted that a screw hole may be formed in the inverter cover 11, and an insertion hole may be formed in the motor cover 21. In addition, the connection between the inverter 10 and the electric motor 20 is not limited to bolts, and other structures may be used. In addition, the inverter 10 and the electric motor 20 may also be connected via other components. The inverter cover 11 is not a necessary structural element of the inverter 10 and can be omitted. At this time, the inverter 10 and the electric motor 20 are connected via a portion produced as an exterior of the inverter 10 or the other components.

[0033] The inverter body 14 is a component having a plate-like outer shape. More specifically, the dimension of the inverter body 14 in the thickness direction is shorter than the radial dimension of the inverter body 14. The thickness direction of the inverter body 14 is parallel to the axial direction. The thickness direction of the circuit substrate formed inside the inverter body 14 is consistent with the thickness direction of the outer shape. The inverter body 14 generates a driving current using the power stored in the battery 5 and supplies the driving current to the electric motor 20. In detail, a direct current is supplied from the battery 5 to the inverter body 14 via the terminal 15. The terminal 15 is arranged on the radially outer surface of the inverter cover 11. The terminal 15 and the battery 5 are configured to be electrically connected by wires. It should be noted that the positive terminal and the negative terminal are adjacently arranged at the terminal 15. The inverter body 14 converts the direct current into an alternating current to generate a driving current. In addition, the inverter body 14 and the motor body 24 are electrically connected via the conductor 33. In this embodiment, since three-phase alternating current is used, three conductors 33 are provided. That is, the motor body 24 is a three-phase AC motor. The drive current generated by the inverter body 14 is supplied to the motor body 24 via the three conductors 33 .

[0034] The conductor 33 supplies power from the inverter 10 to the electric motor 20. The conductor 33 is connected to the inverter body 14 and to the motor body 24 via the motor cover 21. Furthermore, the conductor 33 is arranged on a surface that is continuous with the overlapping surface where the inverter 10 and the electric motor 20 are in surface contact. In this embodiment, the inverter cover 11 and the motor cover 21 are in surface contact. That is, the place where the inverter cover 11 and the motor cover 21 are in surface contact is equivalent to the "overlapping surface". Compared with a structure in which the inverter 10 and the electric motor 20 are separately arranged and connected with an electric wire, in this embodiment, electrical connection can be achieved with a simple structure. In other words, a simple structure means that the length of the conductor such as an electric wire or a bus bar can be shortened. Furthermore, the first sealing member 81 is arranged on the outer side of the overlapping surface than the place where the conductor 33 is arranged. In other words, the conductor 33 is arranged at a place that is waterproofed by the first sealing member 81.

[0035] In this embodiment, the inverter 10 is equivalent to a "current regulator". However, the inverter 10 is an example of a current regulator, and may be a device that amplifies current or regulates the waveform of current to generate a drive current and supplies the drive current to the electric motor 20. For example, when the motor body 24 is a DC motor, the current regulator generates a current for driving the DC motor and outputs it to the DC motor.

[0036] The insulating cover 16 is an insulating plate-shaped component configured to cover the terminal 15. In detail, the insulating cover 16 covers the radial outer side of the terminal 15 and the second side of the terminal 15 in the axial direction. In this way, it is possible to prevent the terminal 15 from contacting other conductive components of the electric vehicle 1 and causing a short circuit. In addition, the terminal 15 can also be protected from impact. It should be noted that the insulating cover 16 can cover only the radial outer side of the terminal 15, or only the axial outer side of the terminal 15. The insulating cover 16 can also be configured at a position to isolate the positive terminal and the negative terminal. The insulating cover 16 is not a necessary structural element of the inverter 10 and can be omitted.

[0037] The first coolant channel 17 is a path through which the coolant for cooling the inverter body 14 passes. In the present embodiment, the first coolant channel 17 is formed in the inverter cover 11. In detail, a portion of the first coolant channel 17 is constituted by a groove and a second inverter cover 13, and the groove is formed on the second side of the axial direction of the first inverter cover 12. In this way, since the first inverter cover 12 can be cooled, the inverter body 14 fixed to the first inverter cover 12 can be fully cooled. The first coolant channel 17 can also be formed in the inverter body 14. Alternatively, the space between the inverter cover 11 and the inverter body 14 can also be used as the first coolant channel 17. It is preferred to form the first coolant channel 17 at a position adjacent to the heat generating portion in the inverter 10. As Figure 3 As shown, the inverter cover 11 is provided with a supply port 18. In the present embodiment, the supply port 18 is provided on the outer side surface of the second side in the axial direction of the inverter cover 11. The supply port 18 is formed at a connection portion where a coolant hose is installed, and the coolant hose supplies the coolant to the motor unit 6. The coolant is supplied from the supply port 18 and passes through the first coolant passage 17. In this way, the inverter body 14 is cooled by heat exchange between the coolant and the inverter body 14. As described below, the coolant that has passed through the first coolant passage 17 is used to cool the motor body 24.

[0038] The electric motor 20 is arranged in an axial direction adjacent to the first side of the inverter 10 and adjacent to the second side of the first power transmission part 40. In detail, the electric motor 20 is mounted on and in contact with the first side of the inverter 10, and the electric motor 20 is mounted on and in contact with the second side of the first power transmission part 40. The outer shape of the electric motor 20 is a cylindrical shape.

[0039] like Figure 3 As shown in FIG. 1 , the electric motor 20 includes a motor cover 21, a motor body 24, a drive shaft 27, a second coolant passage 28, and a discharge port 29. Figure 2 shown.

[0040] The motor cover 21 is a cylindrical component for housing the motor body 24. Figure 2 As shown, a frame mounting portion 21a is formed on the motor cover 21. A plurality of frame mounting portions 21a are formed on the outer peripheral surface of the motor cover 21. The frame mounting portion 21a is a portion for mounting on the frame 2a. A through hole for mounting on the frame 2a is formed in the frame mounting portion 21a. In this embodiment, the electric motor 20 is mounted on the frame 2a, and the inverter 10 or the first power transmission unit 40 may also be mounted on the frame 2a.

[0041] The motor cover 21 is composed of a first motor cover 22 and a second motor cover 23. The first motor cover 22 and the second motor cover 23 are cylindrical in shape. A second sealing member 82 is disposed between the first motor cover 22 and the second motor cover 23. However, the motor cover 21 may be a single component. The first motor cover 22 is disposed radially inwardly compared to the second motor cover 23. In the present embodiment, at the boundary portion between the inverter cover 11 and the motor cover 21, the first length from the shaft position to the outer peripheral surface of the motor cover 21 and the second length from the shaft position to the outer peripheral surface of the inverter cover 11 are the same lengths across the entire circumferential direction. Specifically, the first length from the shaft position to the outer peripheral surface of the second motor cover 23 and the second length from the shaft position to the outer peripheral surface of the first inverter cover 12 are the same lengths across the entire circumferential direction. However, the first length and the second length may be the same lengths only in a portion of the circumferential direction. It should be noted that the frame mounting portion 21a is formed on the second motor cover 23. In this way, it is difficult for the load from the frame 2a to be transmitted to the first motor cover 22.

[0042] The motor cover 21 is fixed to the motor body 24 and covers at least a portion of the motor body 24. Specifically, the first motor cover 22 in the motor cover 21 is fixed to the motor body 24. In this way, the motor cover 21 protects the motor body 24 from impact or water. The fixing method of the motor cover 21 and the motor body 24 is, for example, bolts, and fixing methods other than bolts may also be used. It should be noted that the motor cover 21 is not limited to a cylindrical shape. For example, the motor cover 21 may also be a rectangular parallelepiped shape.

[0043] As described above, the motor cover 21 of the electric motor 20 is connected to the inverter cover 11 of the inverter 10. The second motor cover 23 in the motor cover 21 is connected to the first inverter cover 12 of the inverter cover 11. In the present embodiment, the first side of the inverter cover 11 is open, and the opened portion is covered by the motor cover 21. However, the first side of the inverter cover 11 may be closed. In the present embodiment, the second side of the motor cover 21 in the axial direction is closed. However, the second side of the motor cover 21 in the axial direction may be open, and the opened portion may be covered by the inverter cover 11.

[0044] The motor cover 21 also has a function of connecting to the first power transmission part 40. Specifically, a screw hole for fastening a bolt is formed on the end surface of the first side of the axial direction of the motor cover 21. In addition, a through hole is formed in the first power transmission part 40. The positions of the screw hole of the motor cover 21 and the through hole of the first power transmission part 40 correspond to each other. By aligning these through holes and the screw hole, the motor cover 21 can be inserted and fastened. Figure 2The motor cover 21 and the first power transmission part 40 are connected by the bolts 32 shown. It should be noted that there are various methods for connecting the motor cover 21 and the first power transmission part 40, and different methods can also be used. For example, flanges can be formed on the motor cover 21 and the first power transmission part 40, respectively, and connected by the flanges. Alternatively, they can be connected via other components. In addition, the first side of the motor cover 21 in the axial direction is open. The cover member 41 of the first power transmission part 40 is configured to cover the open portion of the first side of the motor cover 21. A sealing member is arranged between the motor cover 21 and the cover member 41. In detail, a third sealing member 83 is arranged between the cover member 41 of the first power transmission part 40 and the first motor cover 22 of the motor cover 21. A fourth sealing member 84 is arranged between the cover member 41 of the first power transmission part 40 and the second motor cover 23 of the motor cover 21. In this way, water can be prevented from penetrating into the inner side of the motor cover 21 through the overlapping surface of the motor cover 21 and the first power transmission part 40. The waterproof structure of this embodiment is an example, and the position and number of the sealing members may be changed.

[0045] The second motor cover 23 is connected to the inverter cover 11 at the second side in the axial direction. Furthermore, the second motor cover 23 is connected to the first motor cover 22 at the first side in the axial direction via the cover member 41. Therefore, the second motor cover 23 functions as a connecting member that integrally connects the inverter cover 11 and the first motor cover 22. In this way, the degree of freedom of the structure of the first motor cover 22 and the inverter cover 11 is increased compared to when the first motor cover 22 and the inverter cover 11 are directly connected, so the degree of freedom of design can be improved.

[0046] The motor cover 21 is box-shaped because it covers almost the entire motor body 24. In particular, the first motor cover 22 covers almost the entire motor body 24. The first motor cover 22 is coaxial with the motor body 24. However, the motor cover 21 may cover only a portion of the motor body 24.

[0047] The motor cover 21 is made of metal. The first motor cover 22 covers the second motor cover 23, thereby improving the effect of protecting the motor body 24. In addition, by implementing the first motor cover 22 and the second motor cover 23 with different components, the function of supporting the components in the motor body 24 and the function of connecting the motor body 24 and other components can be separated. In this way, the degree of freedom of design can be improved.

[0048] For example, the second motor cover 23 may also be formed with a restriction portion on the second side in the axial direction, and the restriction portion prevents the first motor cover 22 from moving relative to the second motor cover 23 toward the second side. In this case, the second motor cover 23 may also be configured to sandwich and fix the first motor cover 22 from both sides in the axial direction by connecting the cover member 41 and the first motor cover 22 on the first side in the axial direction with the receiving portion of the cover member 41 and the second motor cover 23.

[0049] Ribs are formed on the outer side of the outer peripheral surface of the second motor cover 23 to increase the rigidity of the second motor cover 23 and to improve the heat dissipation of the second motor cover 23 .

[0050] The motor body 24 is a component having a cylindrical outer shape. The motor body 24 generates a driving force using a driving current provided from the inverter body 14. The motor body 24 includes a stator 25 and a rotor 26. A plurality of stators 25 are arranged in the circumferential direction on the inner peripheral surface of the first motor cover 22. The driving current is provided to the stator 25 via the conductor 33. The rotor 26 is mounted on the drive shaft 27. The magnetic field around the rotor 26 changes by providing the driving current to the stator 25. In this way, the rotor 26 rotates integrally with the drive shaft 27. In this way, the motor body 24 generates a driving force. The motor body 24 outputs the generated driving force as a rotational driving force of the drive shaft 27. The drive shaft 27 is arranged at the radial center of the electric motor 20. The drive shaft 27 protrudes from the motor body 24 to the first power transmission unit 40 side. The rotational driving force of the drive shaft 27 is transmitted to the drive wheel, that is, the rear wheel 4 via the first power transmission unit 40. In addition, the drive shaft 27 is mounted on the first motor cover 22 via the first bearing 71.

[0051] The second coolant channel 28 is a path through which the coolant for cooling the motor body 24 passes. In the present embodiment, the second coolant channel 28 is formed in the motor cover 21. Specifically, the second coolant channel 28 is formed between the first motor cover 22 and the second motor cover 23. More specifically, the second coolant channel 28 is formed by forming a groove on the outer surface of the first motor cover 22. By forming the second coolant channel 28 between the first motor cover 22 and the second motor cover 23, it is easier to form the second coolant channel 28 extending in the circumferential direction, and it is easier to form a complex channel. For example, the groove formed in the first motor cover 22 may also be a spiral shape that goes around the circumferential direction of the first motor cover 22 a plurality of times and moves in the axial direction. In addition, it is also possible to form a surrounding groove that goes around the circumferential direction with a gap in the axial direction, and also form a connecting groove that connects the surrounding groove. With such a structure, it is easier to extend the flow path through the second coolant channel 28, and it is easier to reduce the temperature of the stator 25 fixed to the first motor cover 22. Therefore, it is preferred that the second coolant channel 28 is formed at a position close to the first motor cover 22 that fixes the stator 25. The coolant can flow through the outside of the first motor cover 22 by passing the coolant between the first motor cover 22 and the second motor cover 23. In this way, the coolant can be prevented from invading the inside of the first motor cover 22. However, the second coolant channel 28 can also be formed in the motor body 24. Alternatively, the space between the motor cover 21 and the motor body 24 can be used as the second coolant channel 28. It is preferred to form the second cooling channel at a position adjacent to the heat generating portion in the motor body 24, namely the stator 25. As Figure 3 As shown, the second coolant channel 28 is connected to the first coolant channel 17. Therefore, the coolant supplied through the supply port 18 is supplied to the second coolant channel 28 after cooling the inverter body 14, thereby cooling the motor body 24. Figure 3 As shown in FIG. 1 , a discharge port 29 is provided on the outer peripheral surface of the motor cover 21. A connection portion for mounting a coolant hose is formed at the discharge port 29, and the coolant hose discharges the coolant after the coolant is used to cool the motor unit 6. The coolant discharged from the motor unit 6 is supplied to the supply port 18 again after being cooled by the radiator. It should be noted that the supply port 18 and the discharge port 29 may also be formed at positions 180 degrees different in the circumferential direction.

[0052] Generally speaking, the inverter body 14 is more likely to become high temperature than the motor body 24, so the required cooling level is higher. Therefore, by cooling the inverter body 14 before the motor body 24, the inverter body 14 and the motor body 24 can be properly cooled. In addition, in the present embodiment, the first coolant channel 17 and the second coolant channel 28 are connected. That is, channels connected to each other are formed in the first coolant channel 17 and the second coolant channel 28 respectively. Channels connected to each other are, for example, channels extending in the axial direction. By connecting the first coolant channel 17 and the second coolant channel 28, it is not necessary to supply and discharge coolant to the inverter body 14 and the motor body 24 separately. As a result, the number of supply ports 18 and discharge ports 29 can be reduced, and the number of coolant hoses can be reduced.

[0053] The first power transmission unit 40 is disposed adjacent to the first side of the electric motor 20. The first power transmission unit 40 transmits the driving force output from the drive shaft 27 to the drive wheels, that is, the rear wheels 4. "Transmitting to the rear wheels 4" includes a structure that directly transmits the driving force to the rear wheels 4 and a structure that indirectly transmits the driving force to the rear wheels 4.

[0054] like Figure 2 As shown, in detail, the first power transmission part 40 includes a first gear 42, a second gear 43, a transmission shaft 44 and a sprocket 45. In addition, a cover member 41 covering the first gear 42, the second gear 43 and the transmission shaft 44 is installed on the first power transmission part 40. The cover member 41 includes a member covering the first side of the first gear 42 and the like and a member covering the second side of the cover member 41 and the like. The cover member 41 has a function of blocking the first side of the axial direction of the motor cover 21 and is formed in a substantially circular plate shape. The cover member 41 is installed on the second side of the axial direction of the motor cover 21. In detail, the cover member 41 is installed on the first motor cover 22 and the second motor cover 23.

[0055] The drive shaft 27 is mounted on the cover member 41 via the second bearing 72. In this way, both ends of the drive shaft 27 can be rotatably supported. A first gear 42 is fixed to the drive shaft 27. The first gear 42 meshes with the second gear 43 fixed to the transmission shaft 44. In this way, the driving force is transmitted to the second gear 43. In addition, since the gear diameter of the first gear 42 is smaller than the gear diameter of the second gear 43, the driving force is transmitted at a reduced speed. In addition, the transmission shaft 44 is mounted on the cover member 41 via the third bearing 73 and the fourth bearing 74. The third bearing 73 and the fourth bearing 74 are mounted on the cover member 41. A sprocket 45 is fixed to the transmission shaft 44. The sprocket 45 is a rotating body that rotates integrally with the transmission shaft 44. It should be noted that the sprocket 45 may not be fixed to the transmission shaft 44, but may be directly fixed to the drive shaft 27. A transmission chain 60 is wound around the sprocket 45. The transmission chain 60 transmits the driving force to the rear wheel 4.

[0056] Since the motor unit 6 of this embodiment arranges the inverter 10 and the electric motor 20 side by side in the axial direction, the radial dimension of the entire motor unit 6 can be made more compact compared to a layout in which the inverter 10 is arranged radially outside the electric motor 20 .

[0057] Furthermore, by arranging the inverter 10 and the electric motor 20 adjacently with the thickness direction of the inverter 10 along the axial direction, the axial dimension can be made compact. Furthermore, since the terminals 15 protrude radially from the inverter cover 11, the harness connected to the terminals 15 does not protrude in the axial direction, and thus the axial dimension of the motor unit 6 can be made compact. Furthermore, since at least one of the supply port 18 and the discharge port 29 protrudes radially from the inverter cover 11, the hose connected to the supply port 18 or the discharge port 29 does not protrude in the axial direction, and thus the axial dimension of the motor unit 6 can be made compact.

[0058] Secondly, refer to Figure 4 A motor unit 6 in which the first power transmission unit 40 of the first embodiment is replaced with a second power transmission unit 50 will be described.

[0059] The first power transmission part 40 and the second power transmission part 50 have different transmission modes for transmitting power. The transmission mode refers to the mechanical mode of transmitting driving force. The first power transmission part 40 of this embodiment is equipped with a sprocket 45 on the drive shaft 27. Instead, the second power transmission part 50 uses a gear transmission structure to change the speed of the rotational force from the drive shaft 27 and transmit it to the sprocket. It should be noted that the difference in transmission mode is an example. For example, it is also possible to be a power transmission part that can be equipped with a belt transmission mode or a shaft transmission mode.

[0060] The inverter 10 and the electric motor 20 of the first embodiment can be used in various power transmission units having different power transmission modes. Figure 3 The motor unit 6 and Figure 4 The motor unit 6 shown in the figure shares the inverter 10 and the electric motor 20. In this way, the cost of the motor unit 6 can be reduced.

[0061] In the motor unit 6 including the first power transmission part 40, the motor cover 21 is blocked by the cover member 41. Alternatively, in the motor unit 6 including the second power transmission part 50, the motor cover 21 is blocked by the cover member 51. The cover member 51 is formed in a substantially circular plate shape, similar to the cover member 41. The cover member 51 is formed with a through hole in the same place as the cover member 41 of the first embodiment. The shape of the second side in the axial direction of the cover member 51 is the same as the shape of the second side in the axial direction of the cover member 41. Therefore, the cover member 51 can be mounted on the motor cover 21 of the electric motor 20 by the bolt 32.

[0062] The second power transmission unit 50 includes a first gear 52, a second gear 53 and a transmission shaft 54. The drive shaft 27 is mounted on the cover member 51 via a second bearing 75. The first gear 52 is fixed to the drive shaft 27. The first gear 52 meshes with the second gear 53 fixed to the transmission shaft 54. In this way, the driving force is transmitted to the second gear 53. In addition, since the gear diameter of the first gear 52 is smaller than the gear diameter of the second gear 53, the driving force is transmitted at a reduced speed. In addition, the transmission shaft 54 ​​is mounted on the cover member 51 via a third bearing 76 and a fourth bearing 77. The third bearing 76 and the fourth bearing 77 are mounted on the cover member 51. The driving force of the motor unit 6 is output by the transmission shaft 54. The driving force output by the transmission shaft 54 ​​is transmitted to the transmission chain 60 via other transmission mechanisms.

[0063] Secondly, refer to Figure 5 A motor unit 6 according to a second embodiment will be described. In the following description, components identical or similar to those of the above-described embodiment are denoted by the same reference numerals in the drawings, and description thereof may be omitted.

[0064] The motor unit 6 of the second embodiment includes a unit cover 90. The unit cover 90 includes the functions of the inverter cover 11 and the second motor cover 23 of the first embodiment. That is, the unit cover 90 covers the motor body 24 and the inverter body 14. The conductor 33 is arranged so as to penetrate the overlapping surface of the electric motor 20 and the inverter 10. Specifically, the conductor 33 is arranged so as to penetrate the overlapping surface of the motor cover 21 and the inverter body 14. In addition, the overlapping surface is waterproofed by the first sealing member 81.

[0065] Also, in the second embodiment, the first coolant passage 17 is formed between the unit cover 90 and the inverter body 14. The second coolant passage 28 is formed between the unit cover 90 and the motor cover 21.

[0066] Secondly, refer to Figure 6 The motor unit 6 according to the third embodiment will be described.

[0067] In the third embodiment, the structure of the motor cover 21 and the inverter cover 11 is different from that of the first embodiment. Specifically, the motor cover 21 of the third embodiment is open on the second side in the axial direction. Specifically, the first motor cover 22 and the second motor cover 23 are both open on the second side in the axial direction. In addition, the second side in the axial direction of the motor cover 21 is covered by the inverter cover 11. Therefore, the first bearing 71 is arranged on the first inverter cover 12.

[0068] In this way, the axial dimension of the motor cover 21 can be reduced. As a result, the axial dimension of the motor unit 6 can be made more compact.

[0069] Secondly, refer to Figure 7A motor unit 6 according to a fourth embodiment will be described.

[0070] In the third embodiment, the second axial side of the motor cover 21 is covered by the first inverter cover 12. In the fourth embodiment, instead, the second axial side of the motor cover 21 is covered by the inverter body 14.

[0071] In this way, the axial dimensions of the inverter cover 11 and the motor cover 21 can be reduced compared to the motor unit 6 of the first embodiment. As a result, the axial dimensions of the motor unit 6 can be made more compact. In addition, in the first embodiment, a through hole for inserting the conductor 33 needs to be formed in the motor cover 21, but this structure is unnecessary. In other words, the inverter body 14 and the stator 25 of the motor body 24 can be electrically connected with a simple structure. It should be noted that when the motor body 24 is a DC motor, it is easier to implement the motor unit 6 of the fourth embodiment.

[0072] (Feature 1) As described above, the motor unit 6 of the present embodiment and the modified example drives the electric vehicle 1. The motor unit 6 includes the electric motor 20 and the inverter 10. The electric motor 20 generates a driving force and outputs the driving force from the drive shaft 27 provided on the first side in the axial direction. The inverter 10 is disposed adjacent to the axial direction of the electric motor 20, generates a driving current for driving the electric motor 20, and supplies the driving current to the electric motor 20.

[0073] In this way, the radial dimension is less likely to increase compared with a layout in which the inverter 10 is arranged radially outside. As a result, a compact motor unit can be realized. In this embodiment, the inverter can be arranged adjacent to the second side of the axial direction of the electric motor to prevent interference between the drive shaft and the inverter.

[0074] (Feature 2) In the motor unit 6 of the present embodiment, the inverter 10 is arranged so that the thickness direction of the inverter 10 is along the axial direction of the electric motor 20 .

[0075] Since the radial protrusion amount of the inverter 10 can be suppressed, the radial dimension of the motor unit 6 can be made more compact.

[0076] (Feature 3) In the motor unit 6 of the present embodiment, the inverter 10 that converts a direct current into an alternating current to generate a drive current corresponds to the current regulating device.

[0077] The motor unit 6 including the inverter 10 can be made compact.

[0078] (Feature 4) In the motor unit 6 of the present embodiment, the electric motor 20 includes the motor cover 21. The inverter 10 includes the inverter cover 11. The inverter cover 11 is attached to the motor cover 21 so as to contact the motor cover 21.

[0079] Since the motor cover 21 and the inverter cover 11 are attached in contact with each other, the motor unit 6 can be handled integrally.

[0080] (Feature 5) In the motor unit 6 of the present embodiment, the inverter cover 11 has a cylindrical shape coaxial with the motor cover 21 .

[0081] The amount of the inverter cover 11 protruding from the motor cover 21 in the radial direction can be suppressed.

[0082] (Feature 6) In the motor unit 6 of the present embodiment, the terminal 15 for supplying electric power to the inverter 10 is formed on the radially outer side of the inverter cover 11 .

[0083] Since the supply port 18 is arranged outside the inverter cover 11 in the axial direction, the terminal can be arranged at a position avoiding the supply port 18 .

[0084] (Feature 7) In the motor unit 6 of the present embodiment, the inverter cover 11 is provided with the insulating cover 16 which has insulating properties and covers the outside of the terminal 15 .

[0085] This can prevent the terminal 15 from short-circuiting with nearby equipment.

[0086] (Feature 8) In the motor unit 6 of the present embodiment, the conductor 33 is disposed inside the electric motor 20 and the inverter 10. The conductor 33 is disposed along the axial direction and transmits the drive current from the inverter 10 to the electric motor 20.

[0087] Since the electric motor 20 and the inverter 10 are located around the conductor 33 , protection of the conductor 33 is unnecessary or simple.

[0088] (Feature 9) In the motor unit 6 of the present embodiment, the electric motor 20 and the inverter 10 are in contact with each other via the first sealing member 81. The conductor 33 is arranged so as to penetrate the overlapping surface of the electric motor 20 and the inverter 10 or a surface continuous with the overlapping surface. The conductor 33 is arranged in the area sealed by the first sealing member 81.

[0089] The conductor 33 can be shortened by arranging the conductor 33 on the overlapping surface of the electric motor 20 and the inverter 10. In addition, by using the first sealing member 81, the area where the conductor 33 is arranged can be prevented with a simple structure.

[0090] (Feature 10) In the motor unit 6 of the present embodiment, the first coolant passage 17 is formed in the inverter 10. The second coolant passage 28 is formed in the electric motor 20. The first coolant passage 17 and the second coolant passage 28 are connected.

[0091] Since the first coolant passage 17 and the second coolant passage 28 are connected, the supply structure and the discharge structure of the coolant can be shared.

[0092] (Feature 11) In the motor unit 6 of the present embodiment, the inverter 10 is provided with the supply port 18 for supplying the cooling liquid. The electric motor 20 is provided with the discharge port 29 for discharging the cooling liquid passing through the first cooling liquid passage 17 and the second cooling liquid passage 28.

[0093] The cooling liquid can be supplied first to the inverter 10 which is liable to become hot.

[0094] (Feature 12) In the motor unit 6 of this embodiment, at least one of the supply port 18 for supplying the cooling liquid and the discharge port for discharging the cooling liquid is formed outside the inverter 10 in the axial direction. The discharge port 29 is formed outside the electric motor 20 in the radial direction.

[0095] Since the electric motor 20 is not disposed outside the inverter cover 11 in the axial direction, the region can be used to form the supply port 18. Furthermore, since the axial end of the motor cover 21 is closed by the inverter 10, the radially outer region can be used to form the discharge port 29.

[0096] (Feature 13) In the motor unit 6 of this embodiment, it includes a first power transmission part 40 or a second power transmission part 50, which is configured adjacent to the first side of the axial direction of the electric motor 20 and transmits the driving force output from the drive shaft 27 toward the rear wheel 4.

[0097] Since the motor unit 6 includes the first power transmission part 40 or the second power transmission part 50 , a more compact structure can be achieved compared with a structure in which the first power transmission part 40 or the second power transmission part 50 is externally attached.

[0098] (Feature 14) In the motor unit 6 of the present embodiment, the power transmission part is the first power transmission part 40 of the first drive mode or the second power transmission part 50 of the second drive mode. The electric motor 20 includes a motor cover 21. The power transmission part includes cover members 41 and 51. The cover member 41 of the first power transmission part 40 can be mounted on the motor cover 21, and the cover member 51 of the second power transmission part 50 can be mounted on the motor cover 21.

[0099] In this way, the electric motor 20 and the inverter 10 can be shared by the motor unit 6 of the first driving mode and the motor unit 6 of the second driving mode.

[0100] The features 1 to 14 can be combined as appropriate unless there is any contradiction. For example, at least one of the features 1 to N-1 can be combined as appropriate with feature N (N=1, 2, ..., 14).

[0101] As mentioned above, although the preferred embodiment of this application was described, the said structure can be changed as follows, for example.

[0102] In the above embodiment, the inverter 10 has a disk-like outer shape, but may also have a rectangular plate-like outer shape. In this case, the center of the inverter's outer shape is preferably located at a position where the drive shaft 27 passes in order to reduce the radial protrusion from the motor cover 21 .

[0103] The conductor 33 may be formed of a wire or a metal plate when the inverter body 14 and the motor body 24 are not in surface contact. By arranging the conductor 33 between the inverter body 14 and the motor body 24 in the axial direction, the length of the conductor 33 can be shortened. In addition, when the conductor 33 is arranged inside the inverter cover 11 or the motor cover 21, it is possible to prevent the conductor 33 from colliding with obstacles existing outside the motor unit 6.

[0104] The first coolant channel 17 and the second coolant channel 28 are not necessary structural elements and can be omitted. In addition, only one of the first coolant channel 17 and the second coolant channel 28 can be formed. The first coolant channel 17 and the second coolant channel 28 can also be disconnected. In addition, both the supply port 18 and the discharge port 29 can be formed in the inverter cover 11, and both the supply port 18 and the discharge port 29 can be formed in the motor cover 21. When both the supply port 18 and the discharge port 29 are formed in the inverter cover 11 or the motor cover 21, it is preferred to form them on the radially outer surface, that is, the outer peripheral surface. It should be noted that at least one of the supply port 18 and the discharge port 29 can also be formed on the end surface in the axial direction.

[0105] The supply port 18 may be formed outside the inverter cover 11 in the axial direction. The supply port 18 or the discharge port 29 is preferably formed at a position away from the terminal 15. Furthermore, when the supply port 18 or the discharge port 29 is formed in the inverter cover 11, it is preferable that the supply port 18 or the discharge port 29 is arranged at a position lower than the position where the terminal 15 is provided when the motor unit 6 is grounded.

[0106] It is preferred that the direction in which the terminal 15 protrudes from the inverter cover 11 and the direction in which the hose is connected to the supply port 18 or the discharge port 29 are formed in the same direction. In this way, the direction in which the hose connected to the motor unit 6 extends and the direction in which the harness connected to the terminal 15 extends can be made consistent, making it easier to share the space for connecting the hose and the harness.

[0107] The conductor 33 is preferably arranged inside the inverter cover 11 and the motor cover 21, and the first coolant passage 17 or the second coolant passage 28 is preferably formed in a space separated by a wall from the space accommodating the conductor 33. In the above embodiment, the conductor 33 and the second coolant passage 28 are respectively formed in two spaces separated by the motor cover 21. In addition, the conductor 33 and the first coolant passage 17 are respectively arranged in two spaces in the inverter 10 separated by a wall separating the electrical components and the first coolant passage 17.

Claims

1. A motor unit for driving a vehicle, characterized in that : The motor unit includes an electric motor and a current regulating device. The electric motor generates a driving force and outputs the driving force from a driving shaft arranged on a first side in an axial direction. The current regulating device is arranged adjacent to the axial direction of the electric motor, generates a driving current for driving the electric motor, and supplies the driving current to the electric motor.

2. The motor unit according to claim 1, characterized in that : The current regulating device is arranged such that a thickness direction of the current regulating device is along an axial direction of the electric motor.

3. The motor unit according to claim 1 or 2, characterized in that : The current adjustment device is an inverter, and the inverter converts a direct current into an alternating current to generate the driving current.

4. The motor unit according to claim 1 or 2, characterized in that : The electric motor comprises a motor cover, The current regulating device comprises a regulating device cover, The adjustment device cover is mounted on the motor cover in such a manner as to contact the motor cover.

5. The motor unit according to claim 4, characterized in that : The adjustment device cover is in a cylindrical shape coaxial with the motor cover.

6. The motor unit according to claim 4, characterized in that : A terminal for supplying electric power to the current adjusting device is formed on the radially outer side of the adjusting device cover.

7. The motor unit according to claim 6, characterized in that : The adjusting device cover is provided with an insulating cover having insulating properties and covering the outer side of the terminal.

8. The motor unit according to claim 1 or 2, characterized in that : Conductors are arranged inside the electric motor and the current regulating device. The conductor is arranged along the axial direction and transmits the drive current from the current adjustment device to the electric motor.

9. The motor unit according to claim 8, characterized in that : The electric motor and the current regulating device are in contact with each other via a sealing member. The conductor is arranged so as to penetrate the overlapping surface of the electric motor and the current regulating device or a surface continuous with the overlapping surface. The conductor is arranged in a region sealed against water by the sealing member.

10. The motor unit according to claim 1 or 2, characterized in that : A first cooling liquid channel is formed in the current regulating device, A second coolant channel is formed in the electric motor, The first coolant channel and the second coolant channel are connected.

11. The motor unit according to claim 10, characterized in that : The current regulating device is provided with a supply port for supplying cooling liquid. The electric motor has a discharge port formed therein for discharging the coolant having passed through the first coolant passage and the second coolant passage.

12. The motor unit according to claim 10, characterized in that : At least one of a supply port for supplying cooling liquid or a discharge port for discharging cooling liquid is formed on a radially outer side of the electric motor.

13. The motor unit according to claim 1 or 2, characterized in that : The motor unit includes a power transmission portion that is disposed adjacent to the first side in the axial direction of the electric motor and transmits a driving force output from the drive shaft toward a drive wheel.

14. The motor unit according to claim 13, characterized in that : The power transmission part is a first power transmission part of a first driving mode or a second power transmission part of a second driving mode, The electric motor comprises a motor cover, A cover member is mounted on the power transmission portion, The cover member of the first power transmission unit may be mounted on the motor cover, and the cover member of the second power transmission unit may be mounted on the motor cover.

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