Planetary gear transmission systems or components – Input from independent power sources – Including electric motor input
Reexamination Certificate
2001-08-31
2003-06-10
Lorence, Richard M. (Department: 3681)
Planetary gear transmission systems or components
Input from independent power sources
Including electric motor input
C180S065230, C180S065510, C180S065600
Reexamination Certificate
active
06575865
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a driving apparatus for automobiles and, more particularly, to a hydraulic pressure generating device for the supply of hydraulic pressure in an apparatus for driving an electric vehicle or a hybrid driving apparatus.
2. Description of Related Art
An apparatus for driving an electric vehicle and a hybrid driving apparatus are known as apparatuses for driving automobiles that use an electric motor (including a generator used as an electric motor in this specification) as a driving source. Since the electric motor is subjected to use under sharp fluctuations in load in such a driving apparatus, the driving apparatus must be provided with a hydraulic pressure generating device and a hydraulic circuit to not only lubricate different mechanical components of the driving apparatus, but also to cool the electric motor under heavy loads and, moreover, to lubricate a gear train if it is included therein for power transmission, and control engagement of a friction device if one is included therein.
An example of a known hydraulic pressure generating device is disclosed in, for example, Japanese Patent Application Laid-Open Publication No. HEI 10-89446. Disclosed in this publication is a hydraulic pressure generating device (
20
; a reference numeral assigned for drawings in the corresponding publication; the same applies to figures in parentheses hereunder) that is connected, through two one-way clutches (
36
,
38
), to a carrier shaft (
127
) coupled to an engine (
150
) and a ring gear shaft (
126
) coupled to a motor (MG
2
) and that supplies a planetary gear (
120
) and other components with a lubricating oil.
An example of a known hydraulic circuit, in which an oil pump (
51
) driven by an engine (
11
) is used as a hydraulic pressure generating device, is disclosed in Japanese Patent Application Laid-Open Publication No. HEI 9-53603. This hydraulic circuit is provided with a first oil passage (A) through which an oil pressure having a required line pressure is introduced to a brake (
28
). It is further provided with, as a sixth oil passage (F), an oil passage for a lubricating system through which the oil pressure is sent to different parts of a driving system comprising power drive transmission elements, such as a countershaft (
31
) and a differential device (
36
), and, as a seventh oil passage (G), an oil passage for a cooling system through which a cooling oil is sent to a generator (
16
) and a driving motor (
25
).
The hydraulic pressure generating device (
20
) disclosed in the above-mentioned Publication No. HEI 10-89446 is formed integrally with a case (
147
) on an end portion opposite to the engine (
150
), which presents a disposition problem in terms of an axial length of a power output device becoming extremely long. In terms of a configuration for oil passages, too, the length of an oil passage for the supply of oil pressure to the planetary gear (
120
) becomes long in conjunction with the above disposition problem. This makes the structure of oil passages in the case (
147
) complicated, which increases the number of man-hours and cost expended in machining. It also increases oil passage resistance, presenting problems of an increased amount of power loss and oil leak in the hydraulic pressure generating device (
20
).
Such problems involved in the oil passage structure become particularly conspicuous in a case, in which the oil pressure from the oil pump (
51
), used as the hydraulic pressure generating device, is supplied to a plurality of locations (brakes, parts of a driving system, and an electric motor) for use in a plurality of purposes (servo pressure control, lubrication, and cooling), as in the art disclosed in the above-mentioned Publication No. HEI 9-53603. It is therefore necessary to dispose the hydraulic pressure generating device in an optimum position, at which the size of the driving apparatus is not affected and, at the same time, the lengths of oil passages to different locations are kept short.
SUMMARY OF THE INVENTION
The invention thus provides a driving apparatus, in which a hydraulic pressure generating device is disposed as efficiently as possible in an internal space thereof from viewpoints of both its own disposition position as well as a configuration of associated oil passages.
To achieve the foregoing, a driving apparatus according to the invention is provided with an electric motor and a differential device that are disposed in a mutually parallel axial relationship, a gear train that operatively couples the electric motor and the differential device by means of a parallel shaft, and a hydraulic pressure generating device. The driving apparatus is characterized in that, in the gear train that comprises a counter drive gear disposed on an axis of the electric motor, a counter driven gear is disposed on a countershaft that runs parallel with the axis of the electric motor and engaged with the counter drive gear, and a differential drive pinion gear is disposed on the countershaft and engaged with a differential ring gear disposed on an axis of the differential device, with the hydraulic pressure generating device disposed in a clearance space created between each of the two adjacent gears of the gear train with the gear train viewed in an axial direction.
In the construction according to a first exemplary aspect of the invention, the hydraulic pressure generating device is disposed in a clearance space created between each of the two adjacent gears of the gear train, which makes it possible to dispose the hydraulic pressure generating device so as not to significantly affect the size of the driving apparatus.
More precisely, the above-mentioned driving apparatus may be constructed such that the electric motor, gear train, and the differential device are housed in a case for the driving apparatus, and the case for the driving apparatus is provided with an intermediate wall that separates at least an electric motor chamber, in which the electric motor is housed, from a gear chamber that houses the gear train with the hydraulic pressure generating device embedded in the intermediate wall.
In the construction according to an embodiment of the first exemplary aspect of the invention, disposing the hydraulic pressure generating device does not require any additional special member, which contributes to a simplified structure and a resultant reduced cost, in addition to a reduced installation space requirement.
It is also effective if a valve body having a circuit formed therein for distributing a pressure oil generated by the hydraulic pressure generating device into the electric motor chamber and the gear chamber is provided in a fixed condition in the intermediate wall to cover the hydraulic pressure generating device.
In the construction according to another embodiment the first exemplary aspect of the invention, the path between the hydraulic pressure generating device and the valve body becomes the shortest, which allows power loss of the hydraulic pressure generating device to be reduced.
In case when the valve body that has the circuit formed therein for distributing the oil pressure generated by the hydraulic pressure generating device into the electric motor chamber and the gear chamber is provided, it would be even more effective if such a valve body has the hydraulic pressure generating device built therein and is embedded in the intermediate wall.
In the construction according to yet another embodiment the first exemplary aspect of the invention, the path between the hydraulic pressure generating device and the valve body becomes the shortest, which allows power loss of the hydraulic pressure generating device to be reduced. Moreover, the valve body as well as the hydraulic pressure generating device is embedded in the intermediate wall, which eliminates the need of any additional special member for disposing the valve body and the hydraulic pressure generating device, which in turn contributes to a simplified structure and a resultant reduced cost, i
Hara Takeshi
Kawaguchi Miyoshi
Takenaka Masayuki
Aisin AW Co. Ltd.
Le David D.
Lorence Richard M.
Oliff & Berridg,e PLC
LandOfFree
Driving apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Driving apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Driving apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3105548