Motor vehicles – Power – Electric
Reexamination Certificate
1998-10-06
2001-08-07
Mar, Michael (Department: 3619)
Motor vehicles
Power
Electric
C180S065510, C180S065100
Reexamination Certificate
active
06269895
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a hybrid drive system which drives a vehicle using an internal engine and a motor/generator. More specifically, it relates to a hybrid drive system using an infinitely variable transmission (IVT).
2. Description of Related Art
A conventional hybrid drive system using a continuously variable transmission (CVT) is proposed as described in Japanese Patent Publication Laying-Open No. 9-71138. In this system, an engine and a motor/generator are directly connected to each other via a damper. Further, the output shafts of the engine and the motor/generator are connected to an oil pump and the CVT via a forward-reverse change mechanism having a forward clutch and a reverse brake, and further connected to vehicle wheels via gears and so on.
When the vehicle is stopped at, for example, an intersection, the engine is stopped in order to improve fuel consumption, and engine surging or reviving is prevented by performing a regenerative control to the motor/generator.
In the aforementioned conventional system, the motor/generator is operated as a motor (starter-motor) at the engine start, and after engine is started, the vehicle is moved by engaging, for example, the forward clutch after waiting for an increase in the hydraulic pressure created by the oil pump.
Therefore, the vehicle can not be moved by the motor/generator when the engine is stopped. As a result, it is difficult to improve the fuel consumption and to reduce the exhaust gases in, for example, a town area in which the vehicle is started and stopped repeatedly.
The vehicle is slow to start moving at the restart because the engagement of the forward clutch and a shift operation of the CVT are performed after the hydraulic pressure is increased according to the rotation of the oil pump which is operated by the engine.
When the engine is stopped during a vehicle stop, the auxiliary equipment can not be operated. Even if an electric motor, separate from the described driving system, such as a motor/generator arranged to drive the auxiliary equipment and the oil pump is provided, another driving system is needed, the vehicle cost is increased, and the system becomes complicated.
Further, even if vehicle movement by the motor/generator, without using the engine, is made possible by interposing a clutch between the engine and the motor/generator, when the clutch is disengaged, the oil pump and the auxiliary equipment can not be operated. Therefore, as discussed, another drive system is needed. Further, the clutch is needed to perform slip control at the start of vehicle movement because the CVT can not shift from rotation 0. Such a system is more complicated. Further, the reliability of the hybrid driving system is decreased, based on the durability of the clutch, due to the slip.
SUMMARY OF THE INVENTION
Therefore an object of the invention is to provide a hybrid drive system solving the aforementioned problem by using an infinitely variable transmission (IVT) which can have a neutral position and can shift from rotation 0.
In order to achieve the aforementioned object, the hybrid drive system comprises an internal engine, a motor/generator which rotates and uses or generates electric energy, and an infinitely variable transmission, which comprises a continuously variable transmission arranged between a primary shaft and a secondary shaft and shifting the torque ratio between the shafts continuously, a planetary gear unit comprising a first rotational element interlocking with a primary side of the continuously variable transmission, a second rotational element interlocking with a secondary side of the continuously variable transmission, and a third rotational element composing rotations of the first rotational element and the second rotational element in a state where a torque circulation occurs and provides an output to driving wheels, and which performs a neutral control self-converging in order that the third rotational element is in a neutral position and a shift control shifting continuously from the neutral position to the continuously variable transmission. In the hybrid drive system, the outputs from the motor/generator and/or the internal engine is transmitted to the driving wheels via the infinitely variable transmission.
An input clutch is arranged between the output shaft of the internal engine and the rotor of the motor/generator. The rotor of the motor/generator interlocks with an oil pump.
The vehicle is started by the torque from the motor/generator with the input clutch disengaged, and the infinitely variable transmission is moved to the neutral position and the oil pump is driven by the motor/generator when the vehicle is stopped.
The vehicle is driven by the power of the internal engine upon engagement of the input clutch, and the power of the internal engine is assisted by the output from the motor/generator or electricity is generated by the motor/generator.
The motor/generator is arranged on the primary shaft, the input clutch is arranged in a bore side of the rotor of the motor/generator, and the oil pump is also arranged on the primary shaft.
The rotor of the motor/generator interlocks with auxiliary equipment of the vehicle.
The motor/generator is arranged on the primary shaft, another shaft interlocks with the auxiliary equipment, and is different from the driving system of the primary shaft, so that the another shaft is drivingly-connected with the primary shaft. A clutch is arranged between the rotor of the motor/generator and the auxiliary equipment.
The vehicle is started by the torque from the motor/generator during the period when input clutch is disengaged, and the infinitely variable transmission is moved to the neutral position and the auxiliary equipment is driven by the motor/generator when the vehicle is stopped.
The oil pump interlocks with the rotor of the motor/generator and the output shaft of the internal engine, and the oil pump is driven by one of the motor/generator and the internal engine. The output shaft of the internal engine and the oil pump are interlocked with each other via a one-way clutch, and the rotor of the motor/generator and the oil pump are directly interlocked with each other.
The motor/generator and the oil pump are arranged on the primary shaft and interlocked, another shaft, different from the primary shaft, interlocks with the output shaft of the internal engine via a one-way clutch.
The auxiliary equipment interlocks with the rotor of the motor/generator and the output shaft of the internal engine, and the auxiliary equipment is driven by one of the motor/generator and the internal engine.
The output shaft of the internal engine interlocks with the auxiliary equipment via a one-way clutch, and the rotor of the motor/generator directly interlocks with the auxiliary equipment.
The another shaft interlocks with the auxiliary equipment and is different from driving system, such as the primary shaft. One end of the another shaft interlocks with the rotor of the motor/generator, and the other end of the another shaft interlocks with the output shaft of the internal engine via a one-way clutch.
The another shaft can also by different from the primary shaft and the secondary shaft, with the motor/generator arranged on the another shaft, and the another shaft interlocks with the primary shaft.
The auxiliary equipment is arranged to interlock with the rotational elements of the infinitely variable transmission except for the third rotational element.
According to the invention, a vehicle is stopped in a state where the infinitely variable transmission is in the neutral position as the motor/generator rotates. Therefore, the oil pump and others can be driven without arranging an exclusive driving source. As a result, a feel of delay does not occur at the vehicle start.
When the vehicle is stopped and when the power required for driving a vehicle is small, for example, when the vehicle is in a state just after the vehicle start, the internal engine remains stopped by disengaging the input clutch. There
Hara Takeshi
Miyagawa Shoichi
Omote Kenji
Suzuki Seiji
Tanuguchi Takao
Aisin Aw Co. Ltd.
Mar Michael
Oliff & Berridg,e PLC
Phan Hau
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