Drive unit for electric vehicles

Abstract

The present disclosure relates to a drive unit for an electric vehicle. An electric motor generator is provided, which includes a rotor and a motor output shaft that rotates integrally with the rotor. A connection shaft is provided, which is able to rotate coaxially with the motor output shaft. A hydraulic clutch is provided, which is interposed between the rotor and the connection shaft. The hydraulic clutch switches between transmission and non-transmission of torque between the rotor and the connection shaft. An auxiliary mechanism is driven by rotation of an input shaft. The input shaft of the auxiliary mechanism is mechanically connected to the connection shaft.

Description

Technical Field

[0001] The present invention relates to a drive unit for an electric vehicle. Background Art

[0002] In the electric vehicle disclosed in Japanese Unexamined Patent Application Publication No. 2010-252584, an internal combustion engine originally installed is removed and an electric motor is installed in place of the internal combustion engine as a driving source of the vehicle. Summary of the Invention

[0003] As in JP2010-252584A, which uses an electric motor instead of an internal combustion engine, it is possible to reuse an electric motor used in another vehicle. Among hybrid vehicles that use an internal combustion engine and an electric motor as drive sources, there is a type of hybrid vehicle in which the output shaft of the internal combustion engine is connected to the output shaft of the electric motor via a clutch. In the electric motor of this type of hybrid vehicle, the clutch is provided as a component integral with the electric motor. In the case where such an electric motor is reused in an electric vehicle, the clutch is installed in the electric vehicle together with the electric motor. However, when the electric motor and the clutch are installed in the electric vehicle, the clutch, which has the function of transmitting the torque of the electric motor to the internal combustion engine in the hybrid vehicle, is an unused component that does not function in any way when installed in the electric vehicle because the internal combustion engine is disconnected.

[0004] A drive unit for an electric vehicle, designed to address the aforementioned issues, includes: a motor including a tubular rotor, a stator, and an output shaft, the stator being located radially outward of the rotor when viewed from the rotor's central axis; the output shaft rotating integrally with the rotor and transmitting the rotor's driving force to a drive wheel; a connecting shaft rotatable coaxially with the output shaft; a hydraulic clutch interposed between the rotor and the connecting shaft, the hydraulic clutch switching between transmitting and not transmitting torque between the rotor and the connecting shaft; and an auxiliary mechanism including an input shaft driven by rotation of the input shaft. The input shaft is mechanically connected to the connecting shaft so that torque from the rotor can be input to the input shaft.

[0005] In this configuration, the motor is connected to the auxiliary mechanism via a clutch and a connecting shaft. Thus, the auxiliary mechanism is driven by the motor's power. In this way, the motor-integrated clutch can be used to transmit the motor's power to the auxiliary mechanism. This allows for efficient use of reusable components without any waste.

[0006] The drive unit for the electric vehicle may include a hydraulic pump that supplies hydraulic fluid to the hydraulic clutch; and a control device that controls the hydraulic pressure of the hydraulic fluid supplied from the hydraulic pump to the hydraulic clutch.

[0007] With the above configuration, the hydraulic clutch can be operated via the control device without considering the operation of the motor switching between transmission and non-transmission of torque. Therefore, the assist mechanism can be freely driven or stopped as needed.

[0008] In a case where the first direction is the direction in which the connecting shaft is located when viewed from the motor along the central axis of the rotor, a drive unit for an electric vehicle may include: a housing that houses the motor, the connecting shaft, and the hydraulic clutch; and an attachment member located in the first direction when viewed from the motor and attached to the housing. The attachment member may include a plurality of bolt holes. The auxiliary mechanism may be connected to the attachment member via bolts inserted into bolt holes among the plurality of bolt holes.

[0009] As in the above-described configuration, the use of the attachment allows any auxiliary mechanism to be positioned appropriately without changing the structure of the attachment for the auxiliary mechanism, which is located inside the housing for the auxiliary mechanism. In other words, the housing can be used in a common manner. Furthermore, the attachment includes a plurality of bolt holes. Thus, by selecting bolt holes at appropriate positions from the plurality of bolt holes according to the shape and size of the auxiliary mechanism to be attached to the attachment, any auxiliary mechanism can be positioned appropriately without changing the attachment for the auxiliary mechanism. In other words, the attachment can be used in a common manner.

[0010] In a drive unit for an electric vehicle, the auxiliary mechanism may be located in the first direction when viewed from the attachment and outside the housing; the connecting shaft may extend through the attachment, the input shaft may be arranged parallel to the connecting shaft, and an endless power transmission component may be provided that is located outside the housing and surrounds the input shaft and the connecting shaft.

[0011] In the case of a connection structure using a stepless power transmission component as in the above-mentioned construction, as long as the input shaft is arranged in parallel with the connecting shaft, the input shaft and the connecting shaft can be connected in such a way that they can rotate as a whole. In other words, as long as the condition that the input shaft is arranged in parallel with the connecting shaft is met, the arrangement of the auxiliary mechanism can be freely changed. As a result, the flexibility of arranging the auxiliary mechanism is enhanced. In addition, since the auxiliary mechanism is located outside the housing, the work of disassembling and attaching the auxiliary mechanism can be easily performed. As a result, for example, replacing the auxiliary mechanism or changing the arrangement of the auxiliary mechanism is not too troublesome.

[0012] In the drive unit for an electric vehicle, the attachment may include a through hole through which the connecting shaft extends, and a bearing rotatably supporting the connecting shaft is located inside the through hole. In this configuration, there is no need to separately provide a structure for supporting the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals represent like elements, and wherein:

[0014] Figure 1 It is a structural diagram of an electric vehicle;

[0015] Figure 2 is a schematic diagram illustrating the connection mode of the drive mechanism in the housing;

[0016] Figure 3 yes Figure 2 an enlarged view of region 3 in FIG; and

[0017] Figure 4 is a plan view of the attachment. DETAILED DESCRIPTION

[0018] An embodiment of an electric vehicle to which a drive unit for an electric vehicle is applied will be described with reference to the accompanying drawings.

[0019] Schematic structure of an electric vehicle

[0020] like Figure 1 As shown in FIG, electric vehicle 100 includes a motor room 102, a dash panel 106, and a passenger compartment 104. Motor room 102 is a space defined in the front portion of electric vehicle 100. Dash panel 106 is a wall portion defining the rear end of motor room 102. Passenger compartment 104 is a space defined on the side of dash panel 106 opposite to motor room 102. Passenger compartment 104 provides a seating space for passengers.

[0021] like Figure 2 As shown in FIG, the electric vehicle 100 includes a housing 10, an attachment 20, a drive mechanism 18, and a drive wheel 108. Figure 1 As shown in the figure, the housing 10 is located in the motor room 102. The housing 10 is made of, for example, aluminum alloy. Figure 2As shown in the figure, the housing 10 includes a shell 12. Moreover, the shell 12 includes a first shell 12A and a second shell 12B. The first shell 12A has a tubular shape as a whole. The second shell 12B has a tubular shape with a bottom as a whole. The first shell 12A and the second shell 12B are integrally connected, wherein an opening of the first shell 12A and an opening of the second shell 12B are connected to each other. The attachment 20 blocks the opening of the first shell 12A on the side opposite to the opening to which the second shell 12B is connected. Therefore, the component resulting from the integration of the shell 12 and the attachment 20 has a cylindrical shape with a space defined inside. Hereinafter, when the above-mentioned two parts forming the shell 12 are described separately, the two parts are respectively referred to as the first shell 12A and the second shell 12B in the description, and when the two parts are described together, the two parts are collectively referred to as the shell 12.

[0022] The drive mechanism 18 is primarily located within the housing 12. It includes a connecting shaft 72, a hydraulic clutch 60, a motor generator 50, a torque converter 82, and a transmission mechanism 86. Along the central axis of the housing 12, these components are arranged in the order described above, from the attachment 20 toward the bottom of the second housing 12B. The hydraulic clutch 60 and the motor generator 50 are individually located at the same respective positions along the central axis of the housing 12. A portion of the connecting shaft 72, the hydraulic clutch 60, and the motor generator 50 are located within the first housing 12A. The connecting shaft 72 extends through the attachment 20 and is partially located outside the housing 12. The torque converter 82 and the main portion of the transmission mechanism 86 are located within the second housing 12B. The transmission mechanism 86 extends through the bottom of the second housing 12B and is partially located outside the housing 12.

[0023] The schematic connection diagram and basic functions of the components of the drive mechanism 18 are as follows. A connecting shaft 72 is connected to the output shaft 52 of the motor generator 50 (hereinafter referred to as the motor output shaft) via a hydraulic clutch 60. The hydraulic clutch 60 switches between transmitting and not transmitting torque between the connecting shaft 72 and the motor output shaft 52. The motor generator 50 is an electric generator motor and serves as the drive source for the electric vehicle 100. The motor output shaft 52 is connected to the input shaft of a torque converter 82. The torque converter 82 is a fluid coupling. The torque converter 82 switches between transmitting and not transmitting torque between its input and output shafts. The torque converter 82 includes a lockup clutch 84. The lockup clutch 84 switches between mechanically connecting and disconnecting the input and output shafts of the torque converter 82. The output shaft of the torque converter 82 is connected to the input shaft of a transmission mechanism 86. The transmission mechanism 86 changes the speed ratio (the speed difference between the input and output shafts) in multiple stages. The transmission mechanism 86 outputs torque according to the speed ratio. The output shaft of the transmission mechanism 86 extends through the housing 12 to the outside of the housing 12. The output shaft of the transmission mechanism 86 is connected to the drive wheel 108 via a differential gear. The differential gear allows a speed difference to occur between the left and right drive wheels 108. Figure 2 In the figure, the differential gear is omitted.

[0024] The electric vehicle 100 includes an inverter 90 and a battery 92. The battery 92 is electrically connected to the motor generator 50 via the inverter 90. The battery 92 supplies power to the motor generator 50 and stores the power supplied from the motor generator 50. Figure 1 As shown in FIG, the battery 92 is located under the floor of the vehicle cabin 104. The inverter 90 performs DC-AC conversion between the battery 92 and the motor generator 50. The inverter 90 is located inside the motor room 102.

[0025] Detailed structure around the motor generator

[0026] In the drive mechanism 18, the motor generator 50, the hydraulic clutch 60 and the connecting shaft 72 are integrally included in the assembly. In the following, the mutual connection structure of these components will be described.

[0027] like Figure 3 As shown in the figure, the hydraulic clutch 60 includes a hub 62, a drum 66, a plurality of first friction plates 63, a plurality of second friction plates 64, an end plate 65, a moving mechanism 67, and a cover 61. The hub 62 generally has a tubular shape with a bottom. A rod-shaped connecting shaft 72 extends through the bottom of the hub 62. The central axis of the hub 62 and the central axis of the connecting shaft 72 coincide with each other. The hub 62 and the connecting shaft 72 rotate integrally. Inside the hub 62, the distal end of the connecting shaft 72 does not reach the opening of the hub 62.

[0028] A plurality of first friction plates 63 are located on the outer circumferential surface of the hub 62. The plurality of first friction plates 63 are arranged along the central axis of the hub 62. Each first friction plate 63 has an annular shape. Each first friction plate 63 protrudes radially from the outer circumferential surface of the hub 62. The first friction plates 63 are movable relative to the hub 62 in a direction along the central axis of the hub 62.

[0029] When viewed from the central axis of the hub 62, the drum 66 is generally located radially outward relative to the hub 62. The drum 66 generally has a tubular shape with a base. The inner diameter of the drum 66 is larger than the outer diameter of the hub 62. The drum 66 receives the hub 62. The opening of the drum 66 faces in a direction opposite to the direction of the opening of the hub 62. The central axis of the drum 66 and the central axis of the hub 62 coincide with each other. The motor output shaft 52, which has a rod-like shape, extends through the bottom of the drum 66. The central axis of the drum 66 and the central axis of the motor output shaft 52 coincide with each other. The drum 66 and the motor output shaft 52 rotate integrally. In other words, the motor output shaft 52 is coaxially rotatable with the connecting shaft 72. The motor output shaft 52 extends into the interior of the hub 62 and faces the connecting shaft 72. In other words, the motor output shaft 52 and the connecting shaft 72 are adjacent to each other along their central axes. In the following, in the directions along the center axes of the connecting shaft 72 and the motor output shaft 52, the direction in which the connecting shaft 72 is located when viewed from the motor output shaft 52 is referred to as the "first direction", and the direction in which the motor output shaft 52 is located when viewed from the connecting shaft 72 is referred to as the "second direction".

[0030] The cover 61 closes the opening of the drum 66. The cover 61 extends through the connecting shaft 72. A plurality of second friction plates 64 are located on the inner circumferential surface of the drum 66. The plurality of second friction plates 64 are located on the inner circumferential surface of the drum 66. The plurality of second friction plates 64 are arranged in a direction along the central axis of the drum 66. Each second friction plate 64 has an annular shape. The second friction plates 64 protrude radially from the inner circumferential surface of the drum 66. The second friction plates 64 are arranged so that the first friction plates 63 and the second friction plates 64 are arranged alternately. The second friction plates 64 face adjacent first friction plates 63, respectively. The second friction plates 64 are movable relative to the drum 66 in a direction along the central axis of the drum 66. Hereinafter, the friction plate group formed by the plurality of first friction plates 63 and the plurality of second friction plates 64 is referred to as a "plate group."

[0031] The end plate 65 is located on the inner circumferential surface of the drum 66. The end plate 65 has an annular shape and radially protrudes from the inner circumferential surface of the drum 66. The end plate 65 is located in a first direction relative to the plate pack. The end plate 65 faces the friction plates located at the end of the plate pack in the first direction. The end plate 65 is immovable relative to the drum 66 in a direction along the central axis of the drum 66.

[0032] The moving mechanism 67 includes a fixed plate 68, a piston 69, a plurality of springs 67A, and a fluid chamber 67B. The fixed plate 68 is located inside the drum 66. The fixed plate 68 has an annular shape. The fixed plate 68 is attached to the motor output shaft 52 via a hole in the center of the fixed plate 68. In other words, the fixed plate 68 protrudes radially from the motor output shaft 52. The fixed plate 68 is immovable relative to the motor output shaft 52 in a direction along the central axis of the motor output shaft 52.

[0033] The piston 69 is located inside the drum 66 between the fixed plate 68 and the bottom of the drum 66. The piston 69 includes a piston body 69A and a contact portion 69B. The piston body 69A has an annular shape. The piston body 69A is attached to the motor output shaft 52 via a hole in the center of the piston body 69A. In other words, the piston body 69A protrudes radially from the motor output shaft 52. The piston body 69A is unable to move relative to the motor output shaft 52 in a direction along the central axis of the motor output shaft 52.

[0034] Contact portion 69B protrudes from piston body 69A in the first direction. Contact portion 69B is located at a portion on the outer circumference of piston body 69A. Contact portion 69B extends continuously over the entire circumference of piston body 69A. The protruding end of contact portion 69B faces the friction plate located at the end of the plate pack in the second direction.

[0035] A plurality of springs 67A are attached to the piston body 69A and the fixed plate 68. The plurality of springs 67A are arranged at equal intervals along the circumference. The plurality of springs 67A bias the piston 69 in the second direction, which is a direction away from the plate group.

[0036] Fluid chamber 67B is a space defined between piston body 69A and the bottom of drum 66. In other words, fluid chamber 67B is located on the side of piston 69 opposite to the plurality of springs 67A and in the second direction relative to piston 69. Fluid chamber 67B is supplied with hydraulic fluid from hydraulic pressure adjustment mechanism 120, described later. Depending on the magnitude relationship between the hydraulic pressure in fluid chamber 67B and the biasing force of the plurality of springs 67A, piston 69 moves toward or away from the plate pack and end plate 65. Consequently, the operating state of hydraulic clutch 60 changes.

[0037] In other words, when the hydraulic pressure in fluid chamber 67B is greater than the biasing force of the multiple springs 67A, piston 69 moves closer to the plate pack and end plate 65. In this case, piston 69, together with end plate 65, clamps the plate pack. Consequently, the adjacent first and second friction plates 63, 64 come into contact with each other. In other words, hydraulic clutch 60 is engaged. In this case, torque is transmitted between hub 62 and drum 66. On the other hand, when the hydraulic pressure in fluid chamber 67B is less than the biasing force of the multiple springs 67A, piston 69 moves away from the plate pack and end plate 65. In this case, piston 69, together with end plate 65, releases the plate pack. Consequently, first and second friction plates 63, 64 are positioned at corresponding, spaced-apart positions. In other words, hydraulic clutch 60 is disengaged. In this case, torque is not transmitted between hub 62 and drum 66.

[0038] The hydraulic clutch 60 is integrated into the motor generator 50 . In addition to the motor output shaft 52 , the motor generator 50 further includes a rotor 53 and a stator 54 .

[0039] When viewed from the central axis of the drum 66, the rotor 53 is located radially outside the drum 66. The rotor 53 has a tubular shape. The inner diameter of the rotor 53 is substantially the same as the outer diameter of the drum 66. The rotor 53 surrounds the drum 66. The inner circumferential surface of the rotor 53 is fixed to the drum 66. The rotor 53 is connected to the motor output shaft 52 via the drum 66. The rotor 53 rotates integrally with the motor output shaft 52.

[0040] The stator 54 includes a stator body 55, a plurality of teeth 56, and a coil 57. When viewed from the central axis of the rotor 53, the stator body 55 is located radially outside the rotor 53. The stator body 55 has a tubular shape. The inner diameter of the stator body 55 is larger than the outer diameter of the rotor 53. The stator body 55 surrounds the rotor 53. The central axis of the stator body 55 coincides with the central axis of the rotor 53.

[0041] A plurality of teeth 56 protrude from the inner circumferential surface of the stator body 55. The plurality of teeth 56 are arranged at equal intervals along the circumference. There is a space between the protruding ends of the plurality of teeth 56 and the outer circumferential surface of the rotor 53. Figure 3 The coil 57 is wound around the plurality of teeth 56. The coil 57 is partially located outside the opposite end surfaces of the stator body 55.

[0042] Attachments

[0043] The motor generator 50 is connected to the housing 12 via the attachment 20. As described above, the attachment 20 is a component that blocks the opening of the first housing 12A. Hereinafter, first, the configuration of the attachment 20 will be described, and then the structure in which the motor generator 50 is attached via the attachment 20 will be described.

[0044] The attachment 20 includes an attachment body 21, a protruding portion 30, a plurality of bolt holes 39, and a plurality of attachment portions 38. The attachment 20 is made of, for example, an aluminum alloy.

[0045] The attachment body 21 has a circular plate-like shape. The attachment body 21 includes a through hole 23 that opens into each opposing surface of the attachment body 21. The inner surface of the through hole 23 includes a body small diameter portion 25 and a body large diameter portion 27 having a larger diameter than the body small diameter portion 25. The body small diameter portion 25 and the body large diameter portion 27 are adjacent to each other. In other words, the inner surface of the through hole 23 has a stepped shape. The center axes of the body small diameter portion 25 and the body large diameter portion 27 coincide with each other. The diameter of the body small diameter portion 25 is larger than the diameter of the connecting shaft 72. The diameter of the body large diameter portion 27 is approximately equal to the outer diameter of the bearing 78 described later. The body large diameter portion 27 and the body step surface 26, which is the step surface between the body small diameter portion 25 and the body large diameter portion 27, constitute the bearing support portion 24.

[0046] The protrusion 30 protrudes from the attachment body 21. More specifically, it protrudes from the surface of the attachment body 21 opposite the opening of the main body large diameter portion 27. The protrusion 30 has a tubular shape. The central axis of the protrusion 30 coincides with the central axis of the through-hole 23. The inner circumferential surface of the protrusion 30 includes a protruding small diameter portion 35 and a protruding large diameter portion 37 having a larger diameter than the protruding small diameter portion 35. The protruding small diameter portion 35 and the protruding large diameter portion 37 coincide with each other. In other words, the inner circumferential surface of the protrusion 30 has a stepped shape. The central axes of the protruding small diameter portion 35 and the protruding large diameter portion 37 coincide with each other. The protruding large diameter portion 37 is closer to the distal end of the protrusion 30 than the protruding small diameter portion 35. The diameter of the protruding small diameter portion 35 is approximately equal to the inner diameter of the stator body 55. The diameter of the protruding large diameter portion 37 is approximately equal to the outer diameter of the stator body 55. The protruding large diameter portion 37 and the protruding step surface 36 , which is a step surface between the protruding large diameter portion 37 and the protruding small diameter portion 35 , constitute the stator support portion 34 .

[0047] A plurality of bolt holes 39 extend through the attachment body 21. Figure 4 As shown in FIG, some of the plurality of bolt holes 39 are located in a portion closer to the outer periphery of the attachment body 21. These bolt holes 39 are arranged circumferentially at equal intervals. In addition, some of the plurality of bolt holes 39 are located in a portion closer to the inner periphery of the attachment body 21. These bolt holes 39 are arranged circumferentially at equal intervals. Figure 4 In order to show the bolt hole 39 in a recognizable manner, the bolt hole 39 is enlarged and exaggerated. Figure 4 , not all of the plurality of bolt holes 39 are illustrated: some of the plurality of bolt holes 39 are skipped.

[0048] A plurality of attachment portions 38 protrude from the outer circumferential surface of the protruding portion 30. The plurality of attachment portions 38 are arranged at equal intervals along the circumference. Each attachment portion 38 has a rectangular plate shape. Each attachment portion 38 includes an attachment hole extending through the attachment portion 38. Figure 4 In order to illustrate the attachment portion 38 in a recognizable manner, the attachment portion 38 is enlarged and exaggerated. Figure 3 , only one of the plurality of attachment portions 38 is illustrated.

[0049] like Figure 3 As shown in the figure, the housing 10 includes a plurality of housing attachment portions 13 as a structural portion for attaching the attachment 20. The plurality of housing attachment portions 13 are located at the end of the first shell 12A in the direction along the central axis of the shell 12. The housing attachment portions 13 protrude from the outer circumferential surface of the first shell 12A. The plurality of housing attachment portions 13 are arranged at equal intervals along the circumference. Each housing attachment portion 13 has a rectangular plate shape. Each housing attachment portion 13 includes an attachment hole extending through the housing attachment portion 13. In Figure 3 , only one of the plurality of housing attachment portions 13 is illustrated.

[0050] Structure for attaching a motor generator

[0051] The motor generator 50 is attached to the attachment 20 constructed as described above. The electric vehicle 100 includes a bearing 78 for attaching the connecting shaft 72 together with the motor generator 50 to the attachment 20.

[0052] When the attachment 20 is attached to the motor generator 50, the attachment body 21 faces the motor generator 50 in a direction along the central axis of the motor output shaft 52 and the connecting shaft 72. The attachment body 21 is positioned in a first direction relative to the motor generator 50. The central axis of the through hole 23 of the attachment body 21 coincides with the central axis of the motor output shaft 52 and the connecting shaft 72. The protrusion 30 protrudes toward the motor generator 50. In other words, of the protruding small diameter portion 35 and the protruding large diameter portion 37, the protruding large diameter portion 37 is closer to the motor generator 50 than the protruding small diameter portion 35. Similarly, of the main body small diameter portion 25 and the main body large diameter portion 27 of the through hole 23, the main body large diameter portion 27 is closer to the motor generator 50 than the main body small diameter portion 25.

[0053] In the arrangement of the attachment 20 described above, the portion of the stator 54 closer to the attachment 20 (i.e., the portion on the first direction side of the stator 54) is fitted into the stator support portion 34 formed by the protrusion 30 of the attachment 20. The stator support portion 34 supports the stator 54. In other words, the protruding large-diameter portion 37 supports the outer circumferential surface of the stator body 55. In addition, the protruding step surface 36 supports the end face of the stator body 55.

[0054] A plurality of bolts B1 extend through the stator body 55. The bolts B1 extend through the entire stator body 55 in the direction along the central axis of the stator body 55. More specifically, each bolt B1 is inserted through the stator body 55 from the second direction side opposite to the protruding step surface 36 toward the first direction side. Each bolt B1 reaches the thick portion of the protrusion 30. The bolts B1 fix the attachment 20 and the motor generator 50 to each other in an integral manner. Figure 3 In FIG, only one of the plurality of bolts B1 is shown.

[0055] Moreover, in the above arrangement of the attachment 20, the connecting shaft 72 extends through the through hole 23. Then, the bearing 78 is embedded between the inner surface of the through hole 23 and the connecting shaft 72. The bearing 78 rotatably supports the connecting shaft 72. Although Figure 3 Although not shown in the figure, bearing 78 has a well-known structure, with multiple balls embedded between an annular outer ring and an annular inner ring. Bearing 78 has an overall annular shape. Bearing 78 is mounted in bearing support portion 24, formed by through-hole 23 of attachment 20. Bearing support portion 24 supports bearing 78. Specifically, the main body large-diameter portion 27 supports the outer circumferential surface of bearing 78. Furthermore, the main body stepped surface 26 supports the end face of the outer ring of bearing 78.

[0056] The attachment member 20 to which the motor generator 50 is attached is attached to the housing 12 via the plurality of housing mounting portions 13. More specifically, when the attachment member 20 is attached to the housing 12, the plurality of attachment portions 38 of the attachment member 20 face the plurality of housing attachment portions 13. Bolts B2 extend through the respective attachment holes of the attachment portions 38 and the housing attachment portions 13 that face each other. The bolts B2 integrally secure the attachment portions 38 and the housing attachment portions 13 to each other.

[0057] Auxiliary institutions

[0058] The electric vehicle 100 includes a compressor 40. The compressor 40 is an auxiliary mechanism that supplies compressed air to an air conditioning unit of the electric vehicle 100. The compressor 40 includes a compressor housing 42, a compressor body 44, and an input shaft 46.

[0059] The compressor housing 42 includes a housing 42A and a plurality of compressor attachment portions 42B. The housing 42A generally has a cylindrical shape, defining a space therein. The plurality of compressor attachment portions 42B are located at ends of the housing 42A along the central axis of the housing 42A. The compressor attachment portions 42B protrude from the outer circumferential surface of the housing 42A. The plurality of compressor attachment portions 42B are arranged at equal intervals along the circumference. Each compressor attachment portion 42B has a rectangular plate-like shape.

[0060] The compressor body 44 is located inside the housing 42A. The compressor body 44 includes a mechanism for supplying compressed air. An input shaft 46 is connected to the compressor body 44. The input shaft 46 extends along the central axis of the housing 42A. The input shaft 46 is rotatably supported by the compressor body 44. When the input shaft 46 rotates, the compressor body 44 is driven. The input shaft 46 extends through the end surface of the housing 42A at the end opposite to the end where the compressor attachment portion 42B is located. In other words, a portion of the input shaft 46 is located outside the housing 42A.

[0061] Like the electric generator 50, the compressor 40 is attached to the housing 10 via the attachment 20. The compressor 40 is located in a first direction relative to the attachment 20. In other words, the compressor 40 is located outside the housing 10. When the compressor 40 is attached to the attachment 20, one end face of the housing 42A of the compressor 40 faces the attachment body 21, and this end face is on the side where the compressor attachment portion 42B is located. A plurality of compressor attachment portions 42B face some of the plurality of bolt holes 39 of the attachment 20. Bolts B3 extend through the corresponding compressor attachment portions 42B. The bolts B3 reach the inside of the bolt holes 39. The bolts B3 fix the compressor attachment portion 42B and the attachment 20 to each other in an integral manner. When the compressor 40 is attached to the attachment 20, the input shaft 46 is parallel to the connecting shaft 72.

[0062] The electric vehicle 100 includes an endless belt 75. The belt 75 is looped around the connecting shaft 72 and the input shaft 46 of the compressor 40. The belt 75 transmits the rotation of the connecting shaft 72 to the input shaft 46.

[0063] Hydraulic adjustment mechanism

[0064] The electric vehicle 100 includes a hydraulic adjustment mechanism 120 and a control device 130 . The hydraulic adjustment mechanism 120 includes a fluid plate 122 , a hydraulic circuit 124 , and a hydraulic pump 126 .

[0065] Fluid pan 122 stores hydraulic fluid. Hydraulic pump 126 is an electric pump driven by a dedicated motor separate from motor generator 50. Hydraulic pump 126 supplies the hydraulic fluid stored in fluid pan 122 to hydraulic circuit 124. Hydraulic circuit 124 is connected to fluid chamber 67B of hydraulic clutch 60. Hydraulic circuit 124 includes solenoid valve 124A. The hydraulic pressure supplied to fluid chamber 67B is adjusted by opening and closing solenoid valve 124A.

[0066] The control device 130 can be configured as one or more processors that perform various types of processing according to a computer program (software). The control device 130 can be configured as one or more dedicated hardware circuits that perform at least some of the various types of processing, such as an application-specific integrated circuit (ASIC), or a circuit system including a combination of these dedicated hardware circuits. The one or more processors include a CPU and a memory (such as RAM and ROM). The memory stores program codes or commands configured to enable the CPU to perform processing. The memory (i.e., a computer-readable medium) can be any available medium that can be accessed by a general or special-purpose computer. The CPU controls the hydraulic adjustment mechanism 120 including the hydraulic pump 126 and the solenoid valve 124A by executing a program stored in the ROM. By controlling the hydraulic adjustment mechanism 120, the CPU controls the hydraulic pressure of the hydraulic fluid to be supplied to the fluid chamber 67B of the hydraulic clutch 60.

[0067] In this embodiment, the drive unit for an electric vehicle includes a motor generator 50 , a hydraulic clutch 60 , a connecting shaft 72 , a compressor 40 , a belt 75 , a bearing 78 , an attachment 20 , a housing 10 , a hydraulic adjustment mechanism 120 , and a control device 130 .

[0068] Method for attaching motor generator and compressor

[0069] A method of attaching the motor generator 50 and the compressor 40 to the housing 10 will be described.

[0070] Motor generator 50 is a reused motor generator originally installed in another vehicle. The other vehicle is a hybrid vehicle that uses an internal combustion engine and a motor generator as its drive source. Some hybrid vehicles include an internal combustion engine and a single motor generator. In this type of hybrid vehicle, the crankshaft, which serves as the output shaft of the internal combustion engine, is sometimes connected to the output shaft of the motor generator via a clutch. In this case, the motor generator has the clutch integrated into the rotor. The motor generator installed in electric vehicle 100 is this type of motor generator. The connecting shaft 72 connected to the hydraulic clutch 60 is a connecting shaft originally used to connect to the crankshaft of the internal combustion engine. In other words, this clutch was originally interposed between the output shaft of the motor generator and the crankshaft, and its function was to switch between the transmission and non-transmission of torque between the output shaft of the motor generator and the crankshaft.

[0071] In order to attach the motor generator 50 and the compressor 40 to the housing 10, various necessary components such as the motor generator 50, the compressor 40, the attachment 20, and the housing 10 are separately provided in advance. As described above, the motor generator 50 is a reused item from another hybrid vehicle and includes the hydraulic clutch 60 and the connecting shaft 72 in an integrated manner. In addition, the housing 10 is divided into a first housing 12A and a second housing 12B. The torque converter 82 and the transmission mechanism 86 are housed in the second housing 12B. The first housing 12A and the second housing 12B are not newly designed housings for the reused motor generator 50, but are housings according to common standards that can be used in other electric vehicles. Similarly, the attachment 20 is an attachment according to common standards that can be used in other electric vehicles and is designed to have dimensions that conform to the housing 10.

[0072] The attachment process is performed as follows. First, the motor generator 50 is attached to the attachment 20, which is not yet attached to the housing 12. More specifically, the bearing 78, into which the connecting shaft 72 is inserted, is placed in the bearing support 24 of the attachment 20. Furthermore, the stator 54 of the motor generator 50 is placed in the stator support 34 of the attachment 20. Then, in this state, the stator 54 is fixed to the attachment 20 via bolts B1.

[0073] Next, the attachment 20 is attached to the housing 12. In other words, the attachment portion 38 of the attachment 20 and the housing attachment portion 13 are aligned and secured to each other via bolts B2. Subsequently, after various adjustments are performed, the first housing 12A and the second housing 12B are connected together. An example of such adjustments is the connection between the motor output shaft 52 and the input shaft of the torque converter 82. Another example of such adjustments is the connection between the hydraulic circuit 124 and the fluid chamber 67B of the hydraulic clutch 60.

[0074] Next, the compressor 40 is attached to the attachment 20. In other words, the bolt holes 39 of the attachment 20 and the compressor attachment portion 42B are aligned and secured to each other via bolts B3. At this time, among the multiple bolt holes 39 provided in the attachment 20, bolt holes 39 located at positions suitable for attaching the compressor 40 to the attachment 20 are used. The bolt holes 39 to be used can be selected based on the shape and size of the compressor housing 42. Furthermore, the bolt holes 39 to be used can be selected taking into account the position of the compressor housing 42 to be arranged in consideration of the arrangement of other components within the motor room 102.

[0075] When the compressor 40 is attached to the attachment 20, the belt 75 is pre-wound in a non-tensioned manner around the input shaft 46 of the compressor 40 and the connecting shaft 72. Then, when the compressor 40 is completely attached, the belt 75 is tensioned.

[0076] Through the above-described process, the motor generator 50 and the compressor 40 can be attached to the housing 10 via the attachment 20 .

[0077] Operation of the embodiment

[0078] The control device 130 adjusts the hydraulic pressure in the fluid chamber 67B of the hydraulic clutch 60 by controlling the hydraulic adjustment mechanism 120. In response to this adjustment, the operating state of the hydraulic clutch 60 changes. In other words, when the hydraulic pressure in the fluid chamber 67B of the hydraulic clutch 60 increases, the hydraulic clutch 60 engages. In this case, torque is transmitted from the rotor 53 of the motor generator 50 to the connecting shaft 72. The torque transmitted to the connecting shaft 72 is input to the input shaft 46 of the compressor 40 via the belt 75. When the input shaft 46 rotates in response to this torque, the compressor body 44 is driven. On the other hand, when the hydraulic pressure in the fluid chamber 67B of the hydraulic clutch 60 decreases, the hydraulic clutch 60 disengages. In this case, no torque is transmitted from the rotor 53 of the motor generator 50 to the connecting shaft 72. In this case, the operation of the belt 75 and the input shaft 46 of the compressor 40 stops. The compressor body 44 then enters a stopped state.

[0079] Effects of the embodiment

[0080] (1) In the case where the motor generator used in another vehicle is reused, the hydraulic clutch 60 and the connecting shaft 72 integrated in the assembly with the motor generator 50 are also reused. In this embodiment, the motor generator 50 is connected to the compressor 40 via the hydraulic clutch 60 and the connecting shaft 72. Therefore, as described in the operation section of the above embodiment, the compressor 40 can be driven by transmitting the power of the motor generator 50 to the compressor 40. In this way, in this embodiment, the hydraulic clutch 60 and the connecting shaft 72 can be used as components for transmitting the power of the motor generator 50 to the compressor 40. In other words, it is possible to effectively use the reused components without generating any waste.

[0081] (2) In this embodiment, as components for switching the operating state of the hydraulic clutch 60, a hydraulic pressure adjustment mechanism 120 dedicated to the hydraulic clutch 60 and a control device 130 for controlling the hydraulic pressure adjustment mechanism 120 are provided. The hydraulic pressure adjustment mechanism 120 and the control device 130 are independent of the operation of the motor generator 50. Therefore, the operating state of the hydraulic clutch 60 can be switched without considering the operation of the motor generator 50. Therefore, the compressor 40 can be freely driven or stopped as needed.

[0082] (3) There are many types of compressors. However, the shape and size of the compressor vary depending on the model. If a compressor of different shapes and sizes is used, it is necessary to change the structure to which the compressor is to be attached according to the shape and size of the compressor. In other words, depending on the model of the compressor 40 installed in the electric vehicle 100, the electric vehicle 100 needs to include an attachment structure suitable for the installed compressor 40.

[0083] To meet these requirements, it is conceivable to modify the structure of the housing 10 according to the shape and size of the compressor 40. However, the housing 10 occupies a considerable volume in the motor chamber 102 and is of considerable size. Therefore, the mold used to manufacture the housing 10 is also of considerable size. In the case of a large mold, modifying the mold shape or preparing a new mold requires considerable cost. Therefore, a design change of the housing 10 results in a significant increase in cost. In addition, the space for accommodating the housing 10 in the motor chamber 102 is limited. From these points of view, it is necessary to use a universal housing for the housing 10.

[0084] Therefore, in this embodiment, the compressor 40 is attached to the housing 10 using the attachment 20. The attachment 20 includes a plurality of bolt holes 39 as a structure for attaching the compressor 40. Using the bolt holes 39 located at appropriate positions among the plurality of bolt holes 39 according to the shape and size of the compressor 40 enables the compressor 40 to be appropriately attached to the attachment 20 regardless of the shape and size of the compressor 40. This embodiment enables the compressor 40 to be appropriately attached to the housing 10 having a predetermined shape regardless of the shape and size of the compressor 40.

[0085] Furthermore, the position to which the compressor 40 is to be attached may be limited in view of the arrangement of other components within the motor room 102. Even in this case, the bolt holes 39 located at appropriate positions among the plurality of bolt holes 39 are used to allow the compressor 40 to be arranged at an appropriate position according to the layout of the interior of the motor room 102, thus enabling the compressor 40 to be attached to the housing 10 having a predetermined shape.

[0086] (4) In this embodiment, the connecting shaft 72 is connected to the input shaft 46 of the compressor 40 using a belt 75. In the case where the connecting shaft 72 and the input shaft 46 are connected using the belt 75, as long as the connecting shaft 72 and the input shaft 46 are arranged parallel to each other, even if the distance between the connecting shaft 72 and the input shaft 46 changes, the connecting shaft 72 and the input shaft 46 can be connected by adjusting the length of the belt 75. In other words, the configuration of this embodiment using the belt 75 allows the position of the compressor 40 to be changed while the connecting shaft 72 and the input shaft 46 are parallel to each other. Thus, due to the layout within the motor room 102 such as described in (3) above, the compressor 40 can be arranged at a necessary position according to the shape and size of the compressor 40 or the requirements for the attachment position of the compressor 40.

[0087] (5) In the present embodiment, the compressor 40 is arranged outside the housing 10. Therefore, even if there is a need to change the attachment position of the compressor 40, the work of removing and attaching the compressor 40 can be easily performed. Therefore, even if there is a need to replace the compressor 40 with a compressor of a different model or change the arrangement of the compressor 40 according to the layout in the motor room 102, such replacement or change work is not troublesome.

[0088] (6) In the present embodiment, the bearing 78 is supported by the attachment 20. More specifically, the outer circumferential surface of the bearing 78 is supported by the main body large diameter portion 27, and the end face of the bearing 78 is supported by the main body step surface 26. The use of this step shape enables the bearing 78 to be stably supported. In addition, in the present embodiment, the stator 54 of the electric generator 50 is supported by the attachment 20. More specifically, the outer circumferential surface of the stator main body 55 is supported by the protruding large diameter portion 37, and the end face of the stator main body 55 is supported by the protruding step surface 36. The use of this step shape enables the stator 54 to be stably supported as well. As described above, the connecting shaft 72 and the hydraulic clutch 60 are integrated with the electric generator 50. Since the bearing 78 supporting the connecting shaft 72 and the stator 54 are both stably supported, the entire electric generator 50 can be stably supported.

[0089] As mentioned above, the mold used to manufacture the housing 10 is a rather large mold. Even if fine structures such as the aforementioned stepped shapes are provided at specific locations in such a mold to support the bearing 78 and the stator 54, it is difficult to accurately determine these locations. On the other hand, the attachment 20 used in this embodiment has a size sufficient to connect the electric generator 50 and the wall surface of the housing 10. In other words, the size of the attachment 20 is quite small compared to the housing 10. Even if fine structures such as stepped shapes are designed at specific locations, the mold used to manufacture such an attachment 20 can be designed with high precision. Therefore, in this embodiment in which a support structure is provided in the attachment 20, the precision of the position where the support structure is provided is enhanced. As a result, the electric generator 50 can be supported more stably.

[0090] Modifications

[0091] This embodiment can be modified as follows: Any combination of this embodiment and the following modifications is possible as long as the combination does not cause technical contradictions.

[0092] The process for attaching the motor generator 50 and the compressor 40 to the housing 10 is not limited to the above example in the embodiment. For example, after the motor generator 50 is attached to the attachment 20, the compressor 40 may be attached to the attachment 20 before the attachment 20 is attached to the housing 10. The attachment 20 may be attached to the housing 10 afterwards.

[0093] The connecting shaft 72 may be divided into two parts, for example, at a middle position in a direction along the central axis of the connecting shaft 72. In other words, the connecting shaft 72 may be constructed by combining a plurality of components.

[0094] The auxiliary mechanism connected to the motor generator 50 is not limited to the compressor 40. The auxiliary mechanism only needs to be driven by the rotation of the input shaft. For example, a pump for power steering can be used as the auxiliary mechanism. The hydraulic pressure generated by driving the pump assists the driver's steering wheel force.

[0095] Multiple auxiliary mechanisms can be attached to the housing 10. Using multiple bolt holes 39 in the attachment 20 enables multiple auxiliary mechanisms to be attached to the attachment 20. In this case, a belt 75 is provided for each auxiliary mechanism, and the positions of the belts 75 are shifted relative to one another along the central axis of the connecting shaft 72. In this state, the belt 75 only needs to be looped around the corresponding input shaft of the auxiliary mechanism and the connecting shaft 72. Therefore, the rotation of the connecting shaft 72 can be transmitted to the input shaft of the corresponding auxiliary mechanism.

[0096] The auxiliary mechanism can be arranged inside the housing 10. Providing a space for arranging the auxiliary mechanism between the attachment 20 and the motor generator 50 enables the auxiliary mechanism to be attached to the attachment 20 inside the housing 10. To provide the space for arranging the auxiliary mechanism between the attachment 20 and the motor generator 50, it is only necessary to adjust the position for setting the stator support portion 34.

[0097] The stepless power transmission component connecting the input shaft of the auxiliary mechanism and the connecting shaft 72 is not limited to the belt 75. For example, a chain can be used as the stepless power transmission component. In this case, it is only necessary to fix the sprockets to the input shaft of the auxiliary mechanism and the connecting shaft 72.

[0098] The configuration for connecting the input shaft of the auxiliary mechanism and the connecting shaft 72 is not limited to the configuration using a stepless power transmission member. For example, the input shaft of the auxiliary mechanism and the connecting shaft 72 may be coaxially arranged and mechanically connected via, for example, a gear mechanism.

[0099] The arrangement of the plurality of bolt holes 39 is not limited to the example in the embodiment. For example, the plurality of bolt holes 39 may be arranged irregularly. In order to enable the auxiliary mechanism to be attached at any of the various positions in the attachment 20, it is preferable to provide the bolt holes 39 at various positions in the attachment 20.

[0100] Depending on the model of the motor generator 50 to be reused, the size of the motor generator 50 may vary. In this case, for example, the diameter of the protruding large-diameter portion 37 included in the stator support portion 34 needs to be changed depending on the model of the motor generator 50. In this case, for example, a plurality of types of attachments 20 having different diameters of the protruding large-diameter portion 37 may be provided in advance, and a suitable one may be selected from the plurality of types of attachments 20.

[0101] The configuration of the stator support portion 34 is not limited to the example in the above embodiment. For example, the stepped shape on the inner circumferential surface of the protrusion 30 can be eliminated, and the inner diameter of the protrusion 30 can be made constant over the entire length of the protrusion 30. Then, the stator support portion 34 can be constructed solely from the inner circumferential surface of the protrusion. In this case, for example, the stator body 55 is pressed against the inner circumferential surface of the protrusion 30, so that the stator 54 can be stably supported.

[0102] It is not necessary to provide a structure for supporting the stator 54 at the attachment 20. For example, if the stator 54 can be supported using an existing structure in the housing 10, the stator 54 does not need to be supported via the attachment 20.

[0103] For example, like the above-described modified example of the stator support portion 34 , the stepped shape at the inner surface of the through hole 23 can be eliminated and the diameter of the through hole 23 can be constant over the entire length of the through hole 23 .

[0104] As with the modified example of the structure for supporting the stator 54 , it is not essential to provide the structure for supporting the bearing 78 at the attachment 20 .

[0105] The structure for attaching the auxiliary mechanism to the attachment 20 is not limited to the structure using the bolt hole 39. For example, as a structure for attaching the auxiliary mechanism to the attachment 20, a recess or a protrusion may be provided in the attachment. The auxiliary mechanism can then be fitted into the recess or pressed into the protrusion.

[0106] The auxiliary mechanism may be attached to the housing 10 without the use of the attachment 20. If the auxiliary mechanism can be attached to the housing 10 using existing structure in the housing 10, the attachment 20 need not be used.

[0107] If the attachment 20 is not used to attach the auxiliary mechanism, the motor generator 50 and the bearing 78 to the housing 10 , the attachment 20 may be eliminated.

[0108] The mechanism for adjusting the hydraulic pressure in the fluid chamber 67B of the hydraulic clutch 60 is not limited to the example in the above embodiment. For example, the hydraulic pressure in the fluid chamber 67B of the hydraulic clutch 60 can be adjusted using the power of the motor generator 50. In this case, the operating state of the hydraulic clutch 60 switches in coordination with the operation of the motor generator 50 (such as the rotation and stop of the rotor 53). When an auxiliary mechanism is connected that requires switching of the driving state in coordination with the operation of the motor generator 50, even if the above method is used for the mechanism for adjusting the hydraulic pressure in the fluid chamber 67B, the auxiliary mechanism can be driven at the appropriate time.

[0109] The material of housing 10 is not limited to the examples in the above embodiment. Housing 10 only needs to be a material suitable for accommodating the components of drive mechanism 18. Considering the weight of the components of drive mechanism 18, the material is preferably sufficiently rigid. Furthermore, considering the heat generated by the components of drive mechanism 18, the material is preferably excellent in heat dissipation.

[0110] The material of the attachment 20 is not limited to the examples in the above-described embodiment. The material of the attachment 20 need only be a material suitable for attaching the motor generator 50 to the housing 12. Similar to the modified example of the material of the housing 10, it is only necessary to use an appropriate material that is suitable in terms of, for example, rigidity and heat dissipation performance. Furthermore, the material of the attachment 20 may be the same as or different from that of the housing 10. The attachment 20 forms part of the heat transfer path from the motor generator 50 to the housing 10. From this perspective, the material of the attachment 20 is preferably a material with a heat transfer efficiency equal to or greater than that of the housing 10.

Claims

1. A drive unit for an electric vehicle, comprising: a motor comprising a tubular rotor, a stator, and an output shaft, the stator being located radially outward of the rotor when viewed from the rotor's central axis, the output shaft rotating integrally with the rotor and transmitting the rotor's driving force to drive wheels; wherein the electric vehicle utilizes only the motor as a drive source, and the motor is a reused motor from a hybrid vehicle utilizing both an internal combustion engine and an electric motor as drive sources; a connecting shaft capable of rotating coaxially with the output shaft; a hydraulic clutch interposed between the rotor and the connecting shaft, the hydraulic clutch switching between transmitting and not transmitting torque between the rotor and the connecting shaft, wherein the hydraulic clutch is a clutch originally provided integrally with the reusable electric motor and used for transmitting torque between the crankshaft of the internal combustion engine and the output shaft of the electric motor in the hybrid vehicle; and an auxiliary mechanism comprising an input shaft, the auxiliary mechanism being driven by rotation of the input shaft, wherein the input shaft is mechanically connected to the connecting shaft so that the torque from the rotor can be input to the input shaft; The driving unit includes: a hydraulic pump that supplies hydraulic fluid to the hydraulic clutch; and A control device controls the hydraulic pressure of the hydraulic fluid supplied from the hydraulic pump to the hydraulic clutch to switch an operating state of the hydraulic clutch regardless of the operation of the motor.

2. The drive unit for an electric vehicle according to claim 1, wherein, in a case where the first direction is a direction in which the connecting shaft is located when viewed from the motor in a direction along the central axis of the rotor, the drive unit comprises: a housing accommodating the motor, the connecting shaft, and the hydraulic clutch, and an attachment member located in the first direction when viewed from the motor and attached to the housing, wherein The attachment includes a plurality of bolt holes, and The auxiliary mechanism is connected to the attachment via a bolt inserted into a bolt hole selected from the plurality of bolt holes.

3. The drive unit for an electric vehicle according to claim 2, wherein: the auxiliary mechanism being located in the first direction when viewed from the attachment and being located outside the housing; The connecting shaft extends through the attachment member; The input shaft is arranged in parallel with the connecting shaft; and A continuously variable power transmission component is provided outside the housing and surrounds the input shaft and the connecting shaft.

4. The drive unit for an electric vehicle according to claim 3, wherein: The attachment includes a through hole through which the connecting shaft extends; and A bearing that rotatably supports the connecting shaft is located inside the through hole.

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