Hybrid vehicle drive system

Abstract

A drive unit for hybrid vehicles has an electric motor 32 arranged above a transmission 61. A transmission housing 5 comprises a right housing 6, a left housing 7, and a cover element 27, arranged in that order from a combustion engine 8, and defines a transmission storage chamber 62 in which the transmission 61 is located. The left housing 7 comprises a left housing body 7g, forming part of the transmission storage chamber 62, and a bulge 7H, which is bulged upwards from the left housing body 7G and to which one end of the electric motor 32 is attached. A mounting bracket 31, to which the mounting device 70 is attached, is formed in front of the bulge 7H on an upper surface of the left housing body 7G. This structure minimizes vibrations of the transmission 61. (For the abbreviated figure: Figure 5)

Description

Title of the invention: DRIVE DEVICE FOR HYBRID VEHICLE technical field

[0001] The present invention generally relates to a drive device for a hybrid vehicle. Previous technique

[0002] Japanese patent no. 5971351 describes a power transmission device for Hybrid vehicles are equipped with an electric motor. The electric motor is attached to a portion of a transmission housing that faces an internal combustion engine. The transmission housing is attached to the motor. The electric motor is coupled to the internal combustion engine at a joint. A line passing through the center of gravity of the electric motor and the joint is positioned, in the axial direction of a crankshaft of the internal combustion engine, such that it intersects a defined line extending in a direction in which the electric motor vibrates due to mechanical vibrations of the internal combustion engine in the absence of the joint.

[0003] With the above arrangements, the hybrid vehicle power transmission device, as taught in the above publication, operates in such a way as to convert a linear motion of the electric motor in the absence of the joint into an oscillatory motion of the latter around the joint, thereby distributing a force introduced from the electric motor to the internal combustion engine through the joint in such a way as to minimize the vibrations of the entire power group.

[0004] Conventional power transmission devices for hybrid vehicles generally have a heavy electric motor arranged away from a mount that attaches a transmission housing to a vehicle body. Such a configuration leads to difficulties in reducing mechanical vibrations. Technical problem

[0005] The invention was carried out taking into account the above problem. One object of the invention is to provide a drive device for hybrid vehicles, capable of minimizing the mechanical vibrations of a transmission. Technical solution

[0006] According to one aspect of the invention, a drive device for a hybrid vehicle is proposed, comprising: (a) a transmission that operates to change the rotational speed at which drive power is transmitted from a motor; (b) a transmission housing in which the transmission is arranged; (c) an engine that transmits drive power to the transmission, and (d) a mounting device that secures the transmission housing to a vehicle body. The engine is arranged above the transmission. The transmission housing comprises a right-hand housing, a left-hand housing, and a cover element arranged in that order from the internal combustion engine. The right-hand housing, the left-hand housing, and the cover element define a transmission storage chamber in which the transmission is disposed. The left-hand housing comprises a left-hand housing body forming part of the transmission storage chamber and a bulge that extends upward from the left-hand housing body and to which one end of the electric motor is attached. A mounting attachment portion to which the mounting device is attached is formed in front of the bulge on an upper surface of the left-hand housing body.

[0007] According to another aspect, the drive device may have the following characteristics, taken individually or in combination:

[0008] - the mounting device is equipped with an elastic element above the part of mounting fixing, and in which an axial center of a motor output shaft is disposed between the mounting fixing part and the elastic element in a vertical direction of the drive device;

[0009] - the drive device further comprises a gear shift unit which operates in such a way as to automatically perform a transmission gear change operation, in which the gear change unit is arranged on an opposite side of the mounting attachment part to the electric motor in a longitudinal direction of the vehicle;

[0010] - the gear-changing unit includes a base plate to which at least A valve-forming unit operating to deliver hydraulic pressure to the transmission is attached, wherein the left-hand housing includes a base plate mounting portion to which the base plate is fixed, the base plate mounting portion being located below the mounting portion in a vertical direction of the vehicle, and wherein the major part of the valve-forming unit is disposed between the mounting portion and the elastic element. Advantages provided

[0011] According to the present invention, it is possible to minimize transmission vibrations. Brief description of the drawings

[0012] Other features, details and advantages of the invention will become apparent from reading the detailed description below and from analyzing the accompanying drawings, in which: Fig. 1

[0013] [Fig-1] is a left-hand view illustrating a drive device for a vehicle hybrid according to an embodiment of the invention; Fig. 2

[0014] [Fig.2] is a plan view illustrating a drive device for a vehicle hybrid according to an embodiment of the invention; Fig. 3

[0015] [Fig.3] is a skeleton view illustrating a drive device for a hybrid vehicle according to an embodiment of the invention; Fig. 4

[0016] [Fig.4] is a cross-sectional view along line IV-IV of [Fig.2]; Fig. 5

[0017] [Fig. 5] is a left-side view illustrating a drive device for a hybrid vehicle on which a mounting device is installed, according to an embodiment of the invention; Fig. 6

[0018] [Fig.6] is a plan view illustrating a drive device for a vehicle hybrid on which a mounting device is installed, according to an embodiment of the invention. Description of the implementation methods

[0019] A drive system for a hybrid vehicle according to an embodiment of the invention comprises: (a) a transmission that operates to change the rotational speed at which drive power is transmitted from an engine; (b) a transmission housing in which the transmission is disposed; (c) an engine that transmits drive power to the transmission; and (d) a mounting device that secures the transmission housing to a vehicle body. The engine is arranged above the transmission. The transmission housing comprises a right-hand housing, a left-hand housing, and a cover element arranged in that order from the internal combustion engine. The right-hand housing, the left-hand housing, and the cover element define a transmission storage chamber in which the transmission is disposed.The left-hand casing comprises a left-hand casing body forming part of the transmission storage chamber and a bulging portion extending upwards from the left-hand casing body, to which one end of the electric motor is attached. A mounting bracket, to which the mounting device is attached, is formed in front of the bulging portion on an upper surface of the left-hand casing body. This drive device structure serves to minimize transmission vibration.

[0020] A drive device for hybrid vehicles according to an embodiment of The invention is described below with reference to the drawings.

[0021] Figs. 1 to 6 are views that illustrate the drive device for hybrid vehicles according to the embodiment of the invention.

[0022] In [Fig. 1] to 6, a vertical direction, a longitudinal direction, and a lateral direction are based on the drive unit mounted in a hybrid vehicle. A direction perpendicular to the longitudinal direction is the lateral direction. A direction along the height of the internal combustion engine is the vertical direction.

[0023] The structure is first described. In [Fig. 1], the hybrid vehicle 1 (which will also be simply referred to as the vehicle, hereafter) is equipped with the vehicle body 2. The vehicle body 2 has the dashboard panel 3 which isolates the front engine compartment 2A and the rear passenger compartment 2B from each other. The drive unit 4 is arranged in the engine compartment 2A. The drive unit 4 is equipped with six forward speeds and one reverse speed and is designed as a drive device for hybrid vehicles within the scope of the invention.

[0024] In [Fig.2], the heat engine 8 is coupled to the drive unit 4. The drive unit 4 is equipped with the transmission housing 5. The transmission housing 5 has the right housing 6, the left housing 7 and the cover element 27 arranged in that order from the heat engine 8.

[0025] The internal combustion engine 8 is attached to the right-hand crankcase 6. The internal combustion engine 8 has the crankshaft 9 (see [Fig. 3]). The crankshaft 9 is arranged to extend in the direction of the width of the vehicle 1. In other words, the internal combustion engine 8 in this embodiment is a transversely mounted engine. The vehicle 1 is a front-engine, front-drive (FF) vehicle.

[0026] The left housing 7 is arranged on the side of the right housing 6 opposite the internal combustion engine 8. In other words, the left housing 7 is attached to the left of the right housing 6. The right housing 6 has a left outer peripheral edge that defines the flange 6F (see [Fig. 2]). In [Fig. 1] and [Fig. 2], the left housing 7 has the flange 7F formed on an outer periphery of its left side.

[0027] The flange 7F, as illustrated in [Fig. 1], has formed on it a plurality of bosses 7f into which the bolts 23A are inserted. The bosses 7f are arranged on the circumference of the flange 7F.

[0028] Similarly, flange 6F has, formed on it, a plurality of bosses, not illustrated, which coincide with the bosses 7f. The bosses of flange 6F and the bosses 7f of flange 7F are fixed together by means of bolts 23A (see [Fig. 1]) so as to join the right-hand housing 6 and the left-hand housing 7.

[0029] The clutch 10 is located in the left-hand housing 6 (see [Fig. 3]). The input shaft 11, the forward output shaft 12, the reverse output shaft 13, the The final reduction mechanism 14 and the differential 15 illustrated in [Fig.3] are arranged inside the left casing 7.

[0030] The input shaft 11, the forward output shaft 12, and the reverse output shaft 13 extend parallel to each other in the lateral direction of the vehicle 1. The forward output shaft 12 constitutes an output shaft of the invention. The input shaft 11, the forward output shaft 12 of the transmission 61, and the differential 15 are arranged in this order.

[0031] In [Fig.3], the input shaft 11 is coupled with the heat engine 8 via the clutch 10, so that the power, as produced by the heat engine 8, is transmitted to the input shaft 11 via the clutch 10. In [Fig.3], the 1st gear input pinion 16A, the 2nd gear input pinion 16B, the 3rd gear input pinion 16C, the 4th gear input pinion 16D, the 5th gear input pinion 16E and the 6th gear input pinion 16F are mounted on the input shaft 11.

[0032] The input pinions 16A and 16B are firmly fixed on the input shaft 11, so that they rotate with the input shaft 11. The input pinions 16C to 16F are free to rotate relative to the input shaft 11.

[0033] The 1st gear output pinion 17A, the 2nd gear output pinion 17B, the 3rd gear output pinion 17C, the 4th gear output pinion 17D, the 5th gear output pinion 17E, the 6th gear output pinion 17F and the final forward drive pinion 17G are mounted on the forward output shaft 12.

[0034] Each output pinion 17A to 17F meshes with a corresponding pinion, which ensures the same gear ratio, from among the input pinions 16A to 16F. For example, the 4th speed output pinion 17D meshes with the 4th speed input pinion 16D.

[0035] The output gears 17A and 17B are free to rotate relative to the forward output shaft 12. The output gears 17C to 17F and the final drive gear 17G are fixed firmly to the forward output shaft 12, so that they rotate with the forward output shaft 12.

[0036] When the 1st gear is reached, the power produced by the internal combustion engine 8 is transmitted from the input shaft 11 to the forward output shaft 12 via the input pinion 16A and the output pinion 17A. When the 2nd gear is reached, the power produced by the internal combustion engine 8 is transmitted from the input shaft 11 to the forward output shaft 12 via the input pinion 16B and the output pinion 17B.

[0037] The first synchronizer 18 is mounted on the forward output shaft 12 between the output pinion 17A and the output pinion 17B.

[0038] When 1st gear is selected by a gear change operation, the first synchronizer 18 couples the 1st gear output pinion 17A with the forward output shaft 12. When 2nd gear is selected by the gear change operation, the first synchronizer 18 couples the 2nd gear output pinion 17B with the forward output shaft 12. When 1st or 2nd gear is reached in the aforementioned manner, the output pinion 17A or the output pinion 17B rotates with the forward output shaft 12.

[0039] The second synchronizer 19 is disposed on the input shaft 11 between the input pinion 16C and the input pinion 16D.

[0040] When the 3rd gear is selected by the gear change operation, the second synchronizer 19 couples the input pinion 16C with the input pinion 11. When the 4th gear is selected by the gear change operation, the second synchronizer 19 couples the input pinion 16D with the input pinion 11. When the 3rd or 4th gear is selected in this way, the input pinion 16C or the input pinion 16D rotates with the input shaft 11.

[0041] When the 3rd gear is reached, the power produced by the internal combustion engine 8 is transmitted from the input shaft 11 to the forward output shaft 12 via the input pinion 16C and the output pinion 17C. When the 4th gear is reached, the power produced by the internal combustion engine 8 is transmitted from the input shaft 11 to the forward output shaft 12 via the input pinion 16D and the output pinion 17D.

[0042] In the manner described above, the second synchronizer 19 mounted on the input shaft 11 operates so as to select a gear set formed by the input gear 16C and the output gear 17C or a gear set formed by the input gear 16D and the output gear 17D in order to deliver power from the input shaft 11 to the forward output shaft 12 via the selected gear set.

[0043] The third synchronizer 20 is disposed on the input shaft 11 between the input pinion 16E and the input pinion 16F.

[0044] When the 5th gear is selected by the gear change operation, the third synchronizer 20 couples the input pinion 16E with the input pinion 11. When the 6th gear is selected by the gear change operation, the third synchronizer 20 couples the input pinion 16F with the input pinion 11. When the 5th or 6th gear is selected in this way, the input pinion 16E or the input pinion 16F rotates with the input shaft 11.

[0045] When 5th gear is engaged, the power produced by the internal combustion engine 8 is transmitted from the input shaft 11 to the forward output shaft 12 via the input pinion 16E and the output pinion 17E. When 6th gear is engaged, the power produced by the internal combustion engine 8 is transmitted from the input shaft 11 to the forward output shaft 12 via the input pinion 16F and the output pinion 17F.

[0046] The third synchronizer 20 mounted on the input shaft 11 operates so as to select a gear set of the input pinion 16E and the output pinion 17E or a gear set of the input pinion 16F and the output pinion 17F in order to deliver power from the input shaft 11 to the forward output shaft 12 via the selected gear set.

[0047] The gear set of input pinion 16D and output pinion 17D and the gear set of input pinion 16E and output pinion 17E are arranged adjacent to each other in the axial direction of the input shaft 11 between the second synchronizer 19 and the third synchronizer 20.

[0048] The reverse gear pinion 22A and the final reverse drive pinion 22B are mounted on the reverse output shaft 13. The reverse gear 22A is free to rotate relative to the reverse output shaft 13 and meshes with the output pinion 17A. The final drive pinion 22B is fixed firmly to the reverse output shaft 13, so that it rotates with the reverse output shaft 13.

[0049] The fourth synchronizer 21 is mounted on the reverse output shaft 13. When a reverse gear is selected by the gear change operation, the fourth synchronizer 21 couples the reverse gear pinion 22A to the reverse output shaft 13, so that the reverse gear pinion 22A rotates with the reverse output shaft 13.

[0050] When the reverse gear ratio is reached, the power produced by the internal combustion engine 8 is transmitted from the input shaft 11 to the reverse output shaft 13 via the input pinion 16A, the output pinion 17A which is movable in rotation relative to the forward output shaft 21, and the reverse pinion 22A.

[0051] The final forward drive pinion 17G and the final reverse drive pinion 22B mesh with the final driven pinion 15A of the differential 15, so that the power from the forward output shaft 12 or the reverse output shaft 13 is delivered to the differential 15 via the final forward drive pinion 17G or the final reverse drive pinion 22B.

[0052] The differential 15 is equipped with the final driven pinion 15A, the differential housing 15B on the outer periphery of which the final driven pinion 15A is mounted, and the differential mechanism 15C disposed in the differential housing 15B.

[0053] The differential housing 15B has cylinder 15c attached to its left end (see [Fig. 4]) and also has a cylinder, not shown, which is similar to cylinder 15c and attached to its right end. The ends of the drive shaft The right 24R and left drive shaft 24L are inserted into the cylinder 15c and the differential housing cylinder 15B, as illustrated in [Fig.3].

[0054] The left and right drive shafts 24L and 24R have their ends connected to the differential mechanism 15C and their other ends connected to left and right drive wheels (not shown). The differential 15 operates so as to distribute the power produced by the internal combustion engine 8 to the left and right drive shafts 24L and 24R by means of the differential mechanism 15C, and then deliver it to the drive wheels. The final driven pinion 15A rotates about the axis of rotation 15a.

[0055] In this embodiment, the input shaft 11, the forward output shaft 12, the input gears 16A to 16F and the output gears 17A to 17F constitute the transmission 61 (also called the speed reducer).

[0056] The final reduction mechanism 14 includes the final forward drive pinion 17G and the final driven pinion 15A.

[0057] In [Fig. 1] and 2, the electric motor 2 comprises the motor housing 32A and the motor shaft 32B, which is retained by the motor housing 32A in a movably rotatable manner. A rotor (not shown) and a stator (not shown), around which a coil is wound, are arranged within the motor housing 32A. The motor shaft 32B is integral with the rotor.

[0058] When a three-phase alternating current ac is supplied to the coil of the electric motor 32, the electric motor 32 produces a rotating magnetic field. The stator operates in such a way as to connect the magnetic flux, as produced by the coil, with the rotor, thereby rotating the rotor fixed to the motor shaft 32B.

[0059] In [Fig. 1] and 4, the transmission housing 5 is equipped with the speed reducer storage chamber 25. The speed reducer storage chamber 25 is defined by the bulged part 7H of the left housing 7 (which will be described in detail later) and by the cover element 27. As illustrated in [Fig. 4], the speed reducer mechanism 33 is arranged in the speed reducer storage chamber 25.

[0060] In [Fig.3] and 4, the speed reduction mechanism 4 is equipped with the first driving pinion 34 mounted on the motor shaft 32B of the electric motor 32, the first intermediate shaft 35, the second intermediate shaft 36, and the 4th speed output pinion 17D mounted on the forward output shaft 12.

[0061] The first driven pinion 35A and the second driving pinion 35B are mounted on the first intermediate shaft 35. The second driven pinion 36A and the third driving pinion 36B are mounted on the second intermediate shaft 36.

[0062] The first driven pinion 35A has a diameter greater than that of the first driving pinion 34 and meshes with the first driving pinion 34.

[0063] The second driving pinion 35B has a smaller diameter than the first driven pinion 35A and the second driven pinion 36A and meshes with the second driven pinion 36A.

[0064] The third driving gear 36B has the same diameter as the second driven gear 36A, but a larger diameter than the 4th gear output gear 17D, and meshes with the 4th gear output gear 17D. It should be noted that, among the gears meshed together, a gear with a larger diameter has more teeth than a gear with a smaller diameter.

[0065] The first driving gear 34 and the first driven gear 35A constitute the first set of speed reduction gears 37 coupling the drive shaft 32B and the first intermediate shaft 35 together. The second driving gear 35B and the second driven gear 36A couple the first intermediate shaft 35 and the second intermediate shaft 36 together and constitute the second set of speed reduction gears 38. The third driving gear 36B and the output gear 17D couple the second intermediate shaft 36 and the forward output shaft 12 together and constitute the third set of speed reduction gears 39.

[0066] As can be seen from the above description, the speed reduction mechanism 33 has the first intermediate shaft 35 and the second intermediate shaft 36 arranged on a power transmission path through which power is transmitted from the electric motor 32 to the forward output shaft 12. The speed reduction mechanism 33 is designed to have driving gears 34, 35B and 36B and driven gears 35A and 36A whose diameters and number of teeth are selected to achieve a desired speed reduction ratio and operates so as to reduce the speed at which the power produced by the electric motor 32 is delivered to the forward output shaft 12.

[0067] The left-hand housing 7 includes an upward-swollen left-end portion to define the swollen portion 7H. The swollen portion 7H is shaped to increase the size of a left-end opening of the left-hand housing 7 in the upward direction. The swollen portion 7H is designed as a housing constituting the storage chamber for the speed reducer 25. The speed reducer mechanism 33 is arranged on the left side of the swollen portion 7H.

[0068] In [Fig. 1] and 2, the cover element 27 is joined or fixed to the left end of the left housing 7 by means of bolts 23B (see [Fig. 1]) and closes the left end opening of the left housing 7, including the bulge 7H. In other words, the bulge 7H and the cover element 27 arranged on the left side of the bulge 7H define the speed reducer storage chamber 25, which is a chamber in which the speed reducer mechanism 33 is disposed.

[0069] In [Fig. 1] and 2, the engine mount 29C is positioned on an upper end portion of the swollen part 7H located near the internal combustion engine 8 (i.e., on its right side). The engine mount 29C has a circular flange shape and is developed ra- dialement so as to have a diameter substantially identical to an outside diameter of the electric motor 32, i.e. of the motor housing 32A.

[0070] The motor mount 29C has a plurality of bosses 29m formed on its outer peripheral part. The bosses 29m are arranged along the circumference of the motor mount 29C. The bolts 23C are inserted into the left sides of the bosses 29m and firmly fixed in threaded holes formed in the motor housing 32A, thus firmly fixing the electric motor 32 to the motor mount 29C.

[0071] The motor mount 29C has a motor mounting surface facing to the right. The electric motor 32 attached to the motor mount 29C is oriented so that the motor shaft 32B extends in the lateral direction of the vehicle 1. The electric motor 32 is exposed externally above the transmission housing 5 and extends in the right-hand direction from the bulge 7H formed by a left-hand portion of the left-hand housing 7.

[0072] The drive shaft 32B of the electric motor 32 is, as illustrated in [Fig.4], arranged to have its center located between the input shaft 11 and the axis of rotation 15a of the final driven pinion 15A in the longitudinal direction of the vehicle 1. More specifically, the longitudinal center of the drive shaft 32B of the electric motor 32 is located between the forward output shaft 12 and the axis of rotation 15a of the final driven pinion 15A in the longitudinal direction of the vehicle 1.

[0073] In [Fig. 1] and 2, the gear change unit 41 is arranged on an upper part of the left housing 7 which is located in front of the electric motor 32 in the longitudinal direction of the vehicle 1. In a plan view of the vehicle 1, the electric motor 32 and the gear change unit 41 are arranged in the vicinity of the mounting fixing part 31.

[0074] In other words, the electric motor 32 and the gear shift unit 41 are arranged on opposite sides of the mounting bracket 31 in the longitudinal direction of the vehicle 1. More specifically, the mounting bracket 31 and the bulging portion 7H are arranged adjacent to each other in the longitudinal direction of the vehicle 1 on the left end portion of the left housing 7. The gear shift unit 41 extends forward from the right side of the mounting bracket 31 in the longitudinal direction of the vehicle 1.

[0075] The gear shift unit 41 is actuated to perform a gear shift operation and a clutch operation of the drive unit 4. The gear shift operation is an operation to change a gear ratio of the drive unit 4. The clutch operation is an operation to selectively engage or disengage the clutch 10 of the drive unit 4.

[0076] The gear change unit 41 is made of a hydraulically actuated device comprising an oil pump, a motor operating so as to activate The oil pump, the valve unit 41B, an accumulator, a reservoir tank in which the operating oil is stored, and the base plate 41A to which the above components are attached. The gear shift unit 41 is therefore made up of a large number of parts and is thus quite heavy.

[0077] In particular, the valve unit 41B has a large number of solenoid valves attached to it and a hydraulically actuated mechanism comprising complex oil paths and cylinders arranged within them. The valve unit 41B is, therefore, a device of considerable weight. The constituent parts of the gear-shifting unit 41 are attached to the base plate 41A, and the base plate 41A is made of a thick metal plate for attaching the constituent parts of the gear-shifting unit 41 to the left-hand housing 7. The base plate 41A is therefore quite heavy.

[0078] In [Fig. 4], the gear shift and selection shaft 42 is located in the left-hand housing 7. The gear shift and selection shaft 42 is movable in its axial direction and is rotatable within the left-hand housing 7. The gear shift and selection shaft 42 is actuated by the gear shift unit 4L

[0079] The gear change and selection shaft 42 is driven by a hydraulic actuator, such as a hydraulic cylinder, installed in the valve forming unit 41B. The valve forming unit 41B is disposed above the gear change and selection shaft 42.

[0080] When a gear shift lever, not shown, is moved by a driver of the vehicle 1 to a drive position or a reverse position, the gear shift unit 41 operates so as to actuate or move the gear shift and selector shaft 42 according to a gear shift map showing a parameter-to-parameter relationship between a position of the throttle valve and a vehicle speed.

[0081] The gear shift and selector shaft 42 is arranged to have an axis extending vertically in front of the input shaft and operates to operate each of the first synchronizers 11 through the fourth synchronizers 18 by means of a gear shifting mechanism consisting of shift calipers, shift shafts, and shift forks (not shown), allowing a selected gear ratio to be achieved. The gear shift unit 41 is designed to actuate the gear shift and selector shaft 42 by means of a hydraulic mechanism or a motor mechanism, but can alternatively be developed to use another type of mechanism to move the gear shift and selector shaft 42.

[0082] The front attachment 46A and the rear attachment 46B are attached to the transmission housing 5, as illustrated in [Fig. 1] and 2. The front attachment 46A connects the electric motor 32 and the right housing 6 to each other and fixes the electric motor 32 to the right housing 6.

[0083] The rear attachment 46B connects the electric motor 32 and the right housing 6 to each other and fixes the electric motor 32 to the right housing 6. As can be seen from the discussion above, the electric motor 32 is arranged outside the transmission housing 5. The electric motor 32 is joined at its left end to the motor support 29C and at its right end, which is opposite the left end in the axial direction of the electric motor 32 to the right housing 6.

[0084] Connector 32C is located at the rear of the electric motor 32. A power cable, not shown, is attached to connector 32C to provide electrical power to activate the electric motor 32.

[0085] In this embodiment, the electric motor 32, as shown in [Fig. 1] and [Fig. 2], has ends opposite each other in the lateral direction of the vehicle 1. The right end of the electric motor 32 will also be designated below as a first end, while the left end of the electric motor 32 will also be designated below as a second end. The electric motor 32 comprises the power receiver 32D and the connector 32C. The power receiver 32D projects outward from the right end (i.e., from the second end) of the electric motor 32 in the direction of the radius of the electric motor 32. The connector 32C is attached at one end of the connector to the left lateral surface (which is oriented in the same direction as the first end of the electric motor 32) of the power receiver 32D.Connector 32C is oriented in the same direction as the first end of the electric motor 32. In other words, connector 32C has an end surface that faces the left side of vehicle 1, that is, is oriented in the same direction as the first end of the electric motor 32.

[0086] The connector 32C is turned in the same direction as the left side (i.e. the first end) of the electric motor 32 is turned, so that the connector 32C is intended to be withdrawn in the longitudinal direction of the motor shaft 32B, thus allowing a power cable which is connected to the connector 32C to be arranged along the electric motor 32.

[0087] The left-hand housing 7 has an upper portion defining the mounting attachment portion 31. The mounting attachment portion 31 has a plurality of bosses 31A formed on a left-hand end portion of the left-hand housing 7 above the input shaft 11. The bosses 31A project upwards. The mounting device 70, which is attached to the vehicle body 2, is fixed to the bosses 31A, thus retaining it in a way elastic the drive unit 4 onto the vehicle body 2 by means of the mounting device 70.

[0088] The electric motor 32 is located away from and above a top surface of the left housing 7 at the rear of the mounting attachment part 31. The internal combustion engine 8 is elastically retained by the vehicle body 2 by means of a mounting device not shown.

[0089] In this embodiment, the electric motor 32 is, as illustrated in [Fig.4], arranged above the transmission 61. The transmission housing 5, as illustrated in [Fig.2], comprises the right housing 6, the left housing 7 and the cover element 27 which are arranged in that order from the internal combustion engine 8. The transmission housing 62 (i.e. a transmission storage chamber) in which the transmission 61 is disposed is, as illustrated in [Fig.4], defined by the right housing 6, the left housing 7 and the cover element 27.

[0090] The left-hand housing 7, as clearly illustrated in [Fig. 1], 2, and 4, comprises the left-hand housing body 7G, which forms part of the transmission storage chamber 62, and the bulging portion 7H, which is bulged upwards from the left-hand housing body 7G and to which one end (i.e., one left end) of the electric motor 32 is attached. The left-hand housing 7 has the mounting attachment portion 31, which is located in front of the bulging portion 7H on the upper surface of the left-hand housing body 7G, and to which the mounting device 70 is attached.

[0091] The mounting device 70, as illustrated in [Fig.5], comprises the drive unit side attachment 71, the elastic element 73 and the vehicle body side attachment 72. The drive unit side attachment 71 and the vehicle body side attachment 72 are joined via the elastic element 73.

[0092] The drive unit side attachment 71a of the junctions with the mounting attachment part 31 of the left housing 7, extends upwards from the junctions, and is fixed inside the elastic element 73. The vehicle body side attachment 72 surrounds the periphery of the elastic element 73 and fixes the elastic element 73 to the vehicle body 2.

[0093] The electric motor 32 has the output shaft 32B whose axial center, viewed from the left side in [Fig. 5], is located between the mounting bracket 31 and the elastic element 73 in the vertical direction. More precisely, the center of the axis of the output shaft (i.e., the motor shaft 32B) of the electric motor 32 is, viewed in its axial direction, located above the mounting bracket 31 and below the junction of the drive unit side attachment 71 and the elastic element 73.

[0094] The center of the motor shaft 32B of the electric motor 32 is, as illustrated in [Fig. 4], located between the input shaft 11 and the center of rotation 15a of the final driven pinion 15A in the longitudinal direction of the vehicle 1. More precisely, the center of the shaft motor 23B of electric motor 32 is arranged between forward output shaft 12 and center of rotation 15a of final driven pinion 15A, as seen in the longitudinal direction of vehicle 1.

[0095] The drive device of this embodiment is equipped with the gear change unit 41 used to automatically perform the gear change operation of the transmission 61. The gear change unit 41 is arranged on the opposite side of the mounting attachment part 31 to the electric motor 32 in the longitudinal direction of the vehicle 1.

[0096] In this embodiment, the gear change unit 41 is, as illustrated in [Fig.5] and 6, equipped with the base plate 41A to which at least the valve-forming unit 41B, operating to deliver hydraulic pressure to the transmission 61, is attached.

[0097] The left housing 7 includes the base plate mounting portion 30 to which the base plate 41A is attached. The base plate mounting portion 30 is located above the left end portion of the left housing 7, in front of the mounting portion 31, on the left side of the mounting portion 31. The base plate mounting portion 30 has a mounting surface to which the base plate 41A is attached, and which is located below a mounting surface of the mounting portion 31 to which the drive unit-side fastener 71 is attached in the vertical direction.

[0098] The bulk of the valve unit 41B is, as seen from the left side in [Fig.5], arranged between the mounting fixing part 31 and the elastic element 73. In particular, the valve unit 41B is, as seen in its axial direction, mainly located above the mounting fixing part 31 and below the junction of the attachment on the drive unit side 71 and the elastic element 73.

[0099] The valve-forming unit 41B is, as shown in [Fig. 6], disposed on one rear side of the entire gear-change unit 41 in the longitudinal direction of the vehicle 1. The valve-forming unit 41B is located in the same position as the electric motor 32 in the lateral direction of the vehicle 1. In other words, the valve-forming unit 41B is aligned with the electric motor 32 in the longitudinal direction of the vehicle 1.

[0100] The operation is described below.

[0101] When the vehicle 1 is moved forward by the internal combustion engine 8, the power, as produced by the internal combustion engine 8, is delivered from the input shaft 11 to one of the output gears 17A to 17F which provides a selected gear ratio, via one of the corresponding input gears 16A to 16F.

[0102] Power is then transmitted from the final drive pinion 17G of the shaft forward gear output 12 to final driven pinion 15A and distributed by differential mechanism 15C from differential 15 to left and right drive shafts 24L and 24R, thus moving vehicle 1 forward.

[0103] When it is necessary for the electric motor 32 to produce torque or power to move the vehicle 1 forward, the power is delivered from the motor shaft 32B to the first driven pinion 35A via the first driving pinion 34.

[0104] Then, the power produced by the electric motor 32 is then transmitted to the 4th speed output pinion 17D via the second driving pinion 35B, the second driven pinion 36A and the third driving pinion 36B.

[0105] The speed reduction mechanism 33 is designed to have driving gears 34, 35B and 36B and driven gears 35A and 36A whose diameters and number of teeth are selected to provide a required gear ratio. The speed at which the power produced by the electric motor 32 is transmitted is reduced by the speed reduction mechanism 33 and then delivered to the forward output shaft 12.

[0106] Power is then delivered from the final driving pinion 17G of the forward output shaft 12 to the final driven pinion 15A to move the vehicle 1 forward.

[0107] As can be seen from the discussion above, the drive unit 4 of this embodiment has the electric motor 32 located above the transmission 61. The transmission housing 5 comprises the right housing 6, the left housing 7 and the cover element 27 which are arranged in that order from the internal combustion engine 8. The right housing 6 is located closest to the internal combustion engine 8. The transmission storage chamber 62 in which the transmission 61 is disposed is defined by the right housing 6, the left housing 7 and the cover element 27.

[0108] The left-hand housing 7 comprises the left-hand housing body 7G, which defines a portion of the transmission storage chamber 62, and the bulging portion 7H, which is bulged upwards from the left-hand housing body 7G and to which the end of the electric motor 32 is attached. The mounting attachment portion 31, to which the mounting device 70 is attached, is formed in front of the bulging portion 7H on the upper surface of the left-hand housing body 7G.

[0109] With the above arrangements, the weight of the heavy electric motor 32 is borne by the mounting fixing part 31, thus minimizing mechanical vibrations of the transmission housing 5. This improves the market quality of the vehicle 1 and also minimizes transmission vibrations.

[0110] In particular, the electric motor 32 is disposed above the transmission housing 5 (i.e., the left housing 7) and, as shown in [Fig. 5], located closer to the junction of the attachment on the drive unit side 71 and the elastic element 73 which is not the transmission 61.

[0111] In the drive unit 4, the mounting device 70 is equipped with the elastic element 73 located above the mounting fixing part 31. The axial center of the output shaft (i.e. the motor shaft 32B) of the electric motor 32 is arranged between the mounting fixing part 31 and the elastic element 73 in the vertical direction.

[0112] With the above arrangements, the electric motor 32 is arranged near the lower side of the elastic element 73 which elastically retains the transmission housing 5 on the vehicle body 2, thus allowing the heavy electric motor 32 to be disposed near the elastic element 73 which is the center of the oscillation movement of the transmission housing 5. This effectively minimizes the vibrations of the transmission housing 5.

[0113] In particular, the drive unit is equipped with the electric motor 32 which is heavy in weight and protrudes out of the transmission housing 5, but capable of minimizing the mechanical vibrations of the latter and ensuring stability in the retention of the drive unit by means of the mounting device 70.

[0114] The drive unit 4 of this embodiment is, as described above, equipped with the gear change unit 41 operating so as to perform the gear change operation of the transmission 61. The gear change unit 41 is arranged on the opposite side of the mounting attachment part 31 to the electric motor 32 in the longitudinal direction of the vehicle 1.

[0115] With the above arrangements, the gear change unit 41 and the heavy electric motor 32 are arranged on opposite sides of the mounting fixing part 31, so that the weights on opposite sides of the mounting fixing part 31 are balanced, thus minimizing mechanical vibration.

[0116] In the drive unit 4 of this embodiment, the gear-changing unit 41 is equipped with the base plate 41A to which the valve-forming unit 41B, which operates to supply hydraulic pressure to the transmission 61, is attached. The left-hand housing 7 is equipped with the base plate mounting portion 30 to which the base plate 41A is attached.

[0117] The base plate fixing part 30 is disposed below the mounting fixing part 31 in the vertical direction of the vehicle 1. The valve unit 41B is interposed between the mounting fixing part 31 and the elastic element 73.

[0118] With the above arrangements, the valve-forming unit 41B, which is relatively long in the vertical direction, is arranged on its lower side. The center of gravity of the valve-forming unit 41B is located near the lower side of the elastic element 73, which elastically attaches the transmission housing 5 to the vehicle body 2, allowing thus to the valve-forming unit 41B which is of heavy weight to be arranged near the center of the oscillating movement (i.e. on a line passing through a junction of the fastener 71 and the elastic element 73 which depends on a location of a part of the heat engine 8 on which the drive unit 4 is mounted), which minimizes mechanical vibrations.

[0119] Although the present invention has been described in terms of the preferred embodiment for ease of understanding, it should be noted that the invention can be implemented in various ways without departing from the principle of the invention. Therefore, the invention should be understood as including all equivalents and possible modifications of the illustrated embodiment that can be implemented without departing from the principle of the invention.

Claims

Demands

1. A drive device for a hybrid vehicle comprising: a transmission (61) that operates to change the rotational speed at which drive power is transmitted from an internal combustion engine (8); a transmission housing (5) in which the transmission is disposed; an electric motor (32) that transmits drive power to the transmission; and a mounting device (70) that secures the transmission housing (5) to a vehicle body, characterized in that the electric motor (32) is arranged above the transmission (61), the transmission housing (5) comprises a right housing (6), a left housing (7), and a cover element (27) arranged in that order from the internal combustion engine (8), the right housing, the left housing, and the cover element defining a transmission storage chamber (62) in which the transmission is disposed.The left-hand casing comprises a left-hand casing body (7G) forming part of the transmission storage chamber (62) and a bulged portion (7H) which is bulged upwards from the left-hand casing body and to which one end of the electric motor is attached, and a mounting attachment portion (31) to which the mounting device (70) is attached is formed in front of the bulged portion on an upper surface of the left-hand casing body.

2. A drive device according to claim 1, wherein the mounting device (70) is equipped with an elastic element above the mounting fixing part (31), and wherein an axial center of a motor output shaft is disposed between the mounting fixing part and the elastic element in a vertical direction of the drive device.

3. A drive device according to claim 2, further comprising a gear shift unit (41) which operates so as to automatically perform a transmission gear shift operation, wherein the gear shift unit (41) is arranged on an opposite side of the mounting attachment part to the electric motor in a longitudinal direction of the vehicle.

4. A drive device according to claim 3, wherein the gear-changing unit (41) comprises a base plate (41A) to which at least one valve-forming unit (41B) operating to deliver hydraulic pressure to the transmission is attached, wherein the left housing (7) comprises a base plate fixing portion (30) to which the base plate is fixed, the base plate fixing portion (30) being located below the mounting fixing portion in a vertical direction of the vehicle, and wherein the major part of the valve-forming unit is disposed between the mounting fixing portion and the elastic element.

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