Hybrid drive system

Abstract

A hybrid drive system configured with an input shaft and a friction type continuously variable transmission (CVT) device. The CVT includes an input member drivingly connected to the input shaft, and an output member. Rotation of the input member is steplessly changed in speed and transmitted to the output member by a shear force of an oil film interposed at the contact position. The drive system includes an electric motor having a dedicated output shaft, a differential device, and a gear transmission device that is structured from a meshing rotary transmission mechanism. A case includes at least a first space filled with traction oil and accommodating the CVT device, and a second space filled with lubricant oil and accommodating the gear transmission device.

1 . A hybrid drive system comprising:
 an input shaft that moves in accordance with an engine;   a friction type continuously variable transmission device that includes an input member that is drivingly connected to the input shaft, and an output member, wherein a contact position between the input member and the output member is changed, and a rotation of the input member is steplessly changed in speed and transmitted to the output member by a shear force of an oil film interposed at the contact position;   an electric motor that includes a dedicated output shaft;   a differential device;   a gear transmission device that forms at least part of a power transmission path that transmits a rotation of the output shaft of the electric motor to the differential device, and is structured from a meshing rotary transmission mechanism; and   a case that includes at least a first space that is filled with traction oil and accommodates the friction type continuously variable transmission device, and a second space that is filled with lubricant oil and accommodates the gear transmission device, wherein the first space and the second space are divided in an oil-tight manner.   
     
     
         2 . The hybrid drive system according to  claim 1 , wherein
 the output shaft of the electric motor is a first shaft,   the input shaft and the input member of the friction type continuously variable transmission device disposed coaxially form a second shaft,   the output member of the friction type continuously variable transmission device is a third shaft,   right and left axle shafts connected to the differential device form a fourth shaft,   the first, second, third, and fourth shafts are arranged mutually parallel and rotatably supported by the case, and gears that form the gear transmission device are disposed on the first, second, third, and fourth shafts, and   the electric motor and the continuously variable transmission device are disposed on a first side in an axial direction of the gear transmission device, and a second side of the gear transmission device is connected to the engine.   
     
     
         3 . The hybrid drive system according to  claim 1 , wherein
 the gear transmission device transmits a rotation of the output shaft of the electric motor to the input member of the friction type continuously variable transmission device, and transmits a rotation of the output member to the differential device.   
     
     
         4 . The hybrid drive system according to  claim 1 , wherein
 the case includes:   a first case member that supports a first end portion of the output shaft of the electric motor, respective first end portions of the input member and the output member of the friction type continuously variable transmission device, and a first end portion of a differential case of the differential device;   a second case member that supports a second end portion of the output shaft of the electric motor, the input shaft, an output shaft mounted with the output member of the friction type continuously variable transmission device, and a second end portion of the differential case of the differential device; and   a partition that supports respective second end portions of the input member and the output member of the friction type continuously variable transmission device, wherein   the first case member and the second case member are connected, and the partition divides the first space and the second space in an oil-tight manner.   
     
     
         5 . The hybrid drive system according to  claim 1 , wherein
 the gear transmission device includes an output gear that is provided on the output shaft of the electric motor, and a differential ring gear that forms an input portion of the differential device, wherein   the output gear and the differential ring gear disposed so as to overlap in the axial direction.   
     
     
         6 . The hybrid drive system according to  claim 5 , wherein
 the gear transmission device includes an intermediate gear that is provided on the input shaft and moves in accordance with the output gear, and an output gear of the continuously variable transmission device that is provided integrated with the output member of the friction type continuously variable transmission device in a rotating direction, wherein   the intermediate gear and the output gear of the continuously variable transmission device are disposed so as to overlap the output gear and the differential ring gear in the axial direction.   
     
     
         7 . The hybrid drive system according to  claim 6 , wherein
 the output gear and the intermediate gear are toothed gears, and power is transmitted between the toothed gears through a toothed idler gear.   
     
     
         8 . The hybrid drive system according to  claim 6 , wherein
 the output gear and the intermediate gear are sprockets, and power is transmitted between the sprockets through a chain wound between the sprockets.   
     
     
         9 . The hybrid drive system according to  claim 7 , wherein
 the toothed idler gear is disposed overlapping the electric motor in a radial direction.   
     
     
         10 . The hybrid drive system according to  claim 1 , wherein
 the friction type continuously variable transmission device is a cone ring type continuously variable transmission device, with the input member and the output member formed from conical friction wheels that are disposed such that axes of the friction wheels are mutually parallel and large diameter portions and small diameter portions of the friction wheels are respectively opposite each other in the axial direction, and a ring provided interposed between opposing inclined surfaces of the friction wheels and moved in the axial direction to steplessly change a speed.   
     
     
         11 . The hybrid drive system according to  claim 1 , wherein
 the input shaft and the input member of the friction type continuously variable transmission device are drivingly connected by a spline.   
     
     
         12 . The hybrid drive system according to  claim 2 , wherein
 the gear transmission device transmits a rotation of the output shaft of the electric motor to the input member of the friction type continuously variable transmission device, and transmits a rotation of the output member to the differential device.   
     
     
         13 . The hybrid drive system according to  claim 12 , wherein
 the case includes:   a first case member that supports a first end portion of the output shaft of the electric motor, respective first end portions of the input member and the output member of the friction type continuously variable transmission device, and a first end portion of a differential case of the differential device;   a second case member that supports a second end portion of the output shaft of the electric motor, the input shaft, an output shaft mounted with the output member of the friction type continuously variable transmission device, and a second end portion of the differential case of the differential device; and   a partition that supports respective second end portions of the input member and the output member of the friction type continuously variable transmission device, wherein   the first case member and the second case member are connected, and the partition divides the first space and the second space in an oil-tight manner.   
     
     
         14 . The hybrid drive system according to  claim 13 , wherein
 the gear transmission device includes an output gear that is provided on the output shaft of the electric motor, and a differential ring gear that forms an input portion of the differential device, wherein   the output gear and the differential ring gear disposed so as to overlap in the axial direction.   
     
     
         15 . The hybrid drive system according to  claim 14 , wherein
 the gear transmission device includes an intermediate gear that is provided on the input shaft and moves in accordance with the output gear, and an output gear of the continuously variable transmission device that is provided integrated with the output member of the friction type continuously variable transmission device in a rotating direction, wherein   the intermediate gear and the output gear of the continuously variable transmission device are disposed so as to overlap the output gear and the differential ring gear in the axial direction.   
     
     
         16 . The hybrid drive system according to  claim 15 , wherein
 the output gear and the intermediate gear are toothed gears, and power is transmitted between the toothed gears through a toothed idler gear.   
     
     
         17 . The hybrid drive system according to  claim 15 , wherein
 the output gear and the intermediate gear are sprockets, and power is transmitted between the sprockets through a chain wound between the sprockets.   
     
     
         18 . The hybrid drive system according to  claim 16 , wherein
 the toothed idler gear is disposed overlapping the electric motor in a radial direction.   
     
     
         19 . The hybrid drive system according to  claim 18 , wherein
 the friction type continuously variable transmission device is a cone ring type continuously variable transmission device, with the input member and the output member formed from conical friction wheels that are disposed such that axes of the friction wheels are mutually parallel and large diameter portions and small diameter portions of the friction wheels are respectively opposite each other in the axial direction, and a ring provided interposed between opposing inclined surfaces of the friction wheels and moved in the axial direction to steplessly change a speed.   
     
     
         20 . The hybrid drive system according to  claim 19 , wherein
 the input shaft and the input member of the friction type continuously variable transmission device are drivingly connected by a spline.