A drive device includes a first motor, a second motor, and circuitry. The first motor includes a first rotation detector and is configured to rotate a driven shaft to apply a driving torque to the driven shaft. The second motor includes a second rotation detector and is configured to rotate the driven shaft to reduce backlash between the first motor and the driven shaft. The circuitry is configured to control the first motor and the second motor, based on a detection signal of the second rotation detector.

A drive device includes a first motor, a second motor, and circuitry. The first motor includes a first rotation detector and is configured to rotate a driven shaft to apply a driving torque to the driven shaft. The second motor includes a second rotation detector and is configured to rotate the driven shaft to reduce backlash between the first motor and the driven shaft. The circuitry is configured to control the first motor and the second motor, based on a detection signal of the second rotation detector.

A dual motor drive assembly comprising a housing, a shaft rotatably mounted with respect to the housing, a first gear connected to and configured to rotate with the shaft, first and second motor circuits, each motor circuit including a motor having an output driving a respective output gear, the output gears being engaged with the first gear, a control circuit adapted to allocate independent torque demands to each of the first and second motors to cause a net torque to be applied to the shaft comprising the sum of the torques applied by the two motors, and a processing circuit adapted to estimate the level of load independent mechanical friction of the system by applying torque demands to the two motors.

A dual motor drive assembly comprising a housing, a shaft rotatably mounted with respect to the housing, a first gear connected to and configured to rotate with the shaft, first and second motor circuits, each motor circuit including a motor having an output driving a respective output gear, the output gears being engaged with the first gear, a control circuit adapted to allocate independent torque demands to each of the first and second motors to cause a net torque to be applied to the shaft comprising the sum of the torques applied by the two motors, and a processing circuit adapted to estimate the level of load independent mechanical friction of the system by applying torque demands to the two motors.

A motor drive system includes motor units to operate in accordance with a unified operation command transmitted from an outside to cause an operation to be accomplished by the motor drive system as a whole. Each motor unit includes a communication circuit to receive the unified operation command, a motor, a storage device to store data representing a rotation direction of the motor associated with the unified operation command, a control circuit, and a drive circuit to cause an electric current to pass through the motor based on a control signal. The control circuit is configured to refer to the data, and generate a control signal to cause the motor to rotate in the rotation direction associated with the unified operation command.

A motor drive system includes motor units to operate in accordance with a unified operation command transmitted from an outside to cause an operation to be accomplished by the motor drive system as a whole. Each motor unit includes a communication circuit to receive the unified operation command, a motor, a storage device to store data representing a rotation direction of the motor associated with the unified operation command, a control circuit, and a drive circuit to cause an electric current to pass through the motor based on a control signal. The control circuit is configured to refer to the data, and generate a control signal to cause the motor to rotate in the rotation direction associated with the unified operation command.

A starting method of a variable speed accelerator, which includes an electric device for generating rotational driving force and a transmission device for changing a speed of the rotational driving force generated by the electric device and transmits the changed rotational driving force to an object to be driven, the starting method includes: a constant speed electric motor starting step of starting a constant speed electric motor and gradually increasing a number of rotations in a first direction of a constant speed rotor and an internal gear; and a generator mode operating step of operating a variable speed electric motor in a generator mode and rotating a planetary gear carrier in the first direction, wherein the transmission device is a planetary gear transmission device, and wherein the electric device comprises: the constant speed electric motor.

Disclosed is a drive train including a drive shaft, a drive machine, and a planetary gearbox having three drives and three outputs, wherein one output is connected to the drive shaft, one drive is connected to the drive machine, and a second drive is connected to an electric differential drive. The differential drive can be connected directly to a network without a frequency converter, in order that the operation of the drive train is possible without a frequency converter.

Disclosed is a drive train including a drive shaft, a drive machine, and a planetary gearbox having three drives and three outputs, wherein one output is connected to the drive shaft, one drive is connected to the drive machine, and a second drive is connected to an electric differential drive. The differential drive can be connected directly to a network without a frequency converter, in order that the operation of the drive train is possible without a frequency converter.

There is provided a hybrid vehicle including an electronic control unit configured to turn on a second inverter in three phases when an accelerator operation amount is equal to or greater than a predetermined operation amount during predetermined traveling in which the hybrid vehicle is traveling with the engine operated in a state in which a first inverter and a second inverter are shut down and when a rotation speed of a first motor is equal to or less than a predetermined rotation speed. Accordingly, it is possible to rapidly increase a rotation speed of the first motor to be higher than a predetermined rotation speed.