A hybrid electric vehicle (HEV) comprises an engine and at least one electric machine. The vehicle is operable in an electric vehicle (EV) mode in which the electric machine develops torque to drive the vehicle whilst the engine is switched off. In an embodiment, the vehicle is operable when in EV mode automatically to cause engine turnover without starting the engine when a prescribed one or more conditions are met.

A hybrid electric vehicle (HEV) comprises an engine and at least one electric machine. The vehicle is operable in an electric vehicle (EV) mode in which the electric machine develops torque to drive the vehicle whilst the engine is switched off. In an embodiment, the vehicle is operable when in EV mode automatically to cause engine turnover without starting the engine when a prescribed one or more conditions are met.

A method for damping juddering in the drive train of a vehicle having an electric motor as the drive motor, and a vehicle having a closed-loop control system to carry out the method. The method includes calculating an electric motor setpoint torque for actuating the electric motor from an electric motor request torque which corresponds to a current request for a torque, and calculating a correction torque as a function of the electric motor request torque and a correction factor which is determined from a rotational speed of the electric motor.

A vehicle transmission includes first and second input gear shafts, an intermediate gear shaft and an output gear shaft. The first input gear shaft has a first torque transmission member, and the second input gear shaft has a first gear wheel. The intermediate gear shaft has second and third gear wheels. The output gear shaft has a fourth gear wheel and a second torque transmission member. The third gear wheel and the fourth gear wheel are arranged to interact with each other for transferring torque from the intermediate gear shaft to the output gear shaft. The first gear wheel and the second gear wheel are arranged to interact with each other for providing a first gear ratio. The first torque transmission member and the second torque transmission member are arranged to interact with each other via a flexible member for providing a second gear ratio.

A vehicle transmission includes first and second input gear shafts, an intermediate gear shaft and an output gear shaft. The first input gear shaft has a first torque transmission member, and the second input gear shaft has a first gear wheel. The intermediate gear shaft has second and third gear wheels. The output gear shaft has a fourth gear wheel and a second torque transmission member. The third gear wheel and the fourth gear wheel are arranged to interact with each other for transferring torque from the intermediate gear shaft to the output gear shaft. The first gear wheel and the second gear wheel are arranged to interact with each other for providing a first gear ratio. The first torque transmission member and the second torque transmission member are arranged to interact with each other via a flexible member for providing a second gear ratio.

A transmission unit for a hybrid motor vehicle, has a planetary gearing. The planetary gearing is fitted with a first planetary wheel set and a second planetary wheel set. The transmission unit also includes an electric machine, which is coupled with a component part of the planetary gearing, and a plurality of switching devices, each of which forming a brake or a clutch, and each being movable between an activated position and a deactivated position. The switching devices are operatively installed for switching various transmission ratios between an input, which can be coupled with an internal combustion engine, and an output, and/or between the electric machine and the output. No more than four switching devices are present for implementing at least two different transmission ratios in a drive state of the internal combustion engine, at least one transmission ratio in a drive state of the electric machine, and at least one transmission ratio in a recuperation state of the electric machine, as a result of their activated and deactivated positions.

A transmission unit for a hybrid motor vehicle, has a planetary gearing. The planetary gearing is fitted with a first planetary wheel set and a second planetary wheel set. The transmission unit also includes an electric machine, which is coupled with a component part of the planetary gearing, and a plurality of switching devices, each of which forming a brake or a clutch, and each being movable between an activated position and a deactivated position. The switching devices are operatively installed for switching various transmission ratios between an input, which can be coupled with an internal combustion engine, and an output, and/or between the electric machine and the output. No more than four switching devices are present for implementing at least two different transmission ratios in a drive state of the internal combustion engine, at least one transmission ratio in a drive state of the electric machine, and at least one transmission ratio in a recuperation state of the electric machine, as a result of their activated and deactivated positions.

To provide a vehicle drive device capable of efficiently driving a vehicle by using in-wheel motors without falling into the vicious cycle between enhancement of driving via the motors and an increase in vehicle weight. The present invention is a vehicle drive device that uses in-wheel motors to drive a vehicle and includes in-wheel motors (20) that are provided in wheels (2b) of a vehicle (1) and drive wheels, in which the in-wheel motors generate the maximum output power in a high revolutions range equal to or more than a predetermined number of revolutions that is more than zero.

To provide a vehicle drive device capable of efficiently driving a vehicle by using in-wheel motors without falling into the vicious cycle between enhancement of driving via the motors and an increase in vehicle weight. The present invention is a vehicle drive device that uses in-wheel motors to drive a vehicle and includes in-wheel motors (20) that are provided in wheels (2b) of a vehicle (1) and drive wheels, in which the in-wheel motors generate the maximum output power in a high revolutions range equal to or more than a predetermined number of revolutions that is more than zero.

There are provided an electric motor (12) that is driven by an engine (8) to generate electric power or assists in a drive of the engine (8) by supply of electric power thereto, a heat exchanger (13) to which cooling air is supplied by a cooling fan (8A), a heat exchanger upstream room (28) that is positioned upstream of the heat exchanger (13) in a flow direction of the cooling air supplied to the heat exchanger (13), and an electricity storage device (30) that stores or discharges electric power. In addition, a radiator (42) for electricity storage device, a cooling pump (43) for electricity storage device and a cooling line (44) for electricity storage device configure a cooling system (41) for electricity storage device that independently cools the electricity storage device (30) aside from the inverter device (34), and the cooling system (41) for electricity storage device is arranged in the heat exchanger upstream room (28).