A clutch, including: inner and outer races; a wedge plate; an electromagnetic actuator including a coil and an attenuating circuit. The coil is arranged to be energized by a power source to switch the wedge clutch between: a locked mode in which the inner and races are locked in a circumferential direction and a free-wheel mode in which the inner race is rotatable with respect to the outer race in the circumferential direction. The attenuating circuit includes a capacitor parallel with the coil and a switch wired to the capacitor. During the free-wheel mode: the switch is arranged to connect the capacitor to an electrical ground; and the electrical power source is arranged to energize the coil and charge the capacitor with a voltage. Following initiation of the locked mode: the switch isolates the capacitor from the electrical ground; and the capacitor discharges the voltage through the coil.

A rotational coupling device includes an armature configured for coupling to a shaft for rotation with the shaft about an axis, but axially movable relative to the shaft. An electromagnet assembly is disposed on one side of the armature and fixed against rotation. A collar is disposed on the opposite side of the armature. The collar is configured for rotation with the shaft, but fixed against axial movement relative to the shaft and includes a permanent magnet. When a current having a first polarity is provided to the electromagnet assembly, the armature moves in one axial direction into engagement with a member of the coupling device to transmit a torque between the member and the armature. The permanent magnet urges the armature in the opposite axial direction to disengage the armature from the member when the current is not provided to the electromagnet assembly.

A drive force control system appropriately controls motors each connected to a corresponding one of drive wheels, so that a vehicle can be propelled with high efficiency. First motor and second motors are controlled in such a manner that a sum of torques transmitted to a right front wheel and a left rear wheel equals to a total value of required torques of the right front wheel and the left rear wheel. A target torque of the first motor and a target torque of the second motor achieving a smallest amount of power output from an electrical power source, for the output torques from the first motor and the second motor are calculated. A torque is generated by the first motor based on the target torque of the first motor calculated, and a torque is generated by the second motor based on the target torque of the second motor calculated.

A clutch, including: inner and outer races; a wedge plate; an electromagnetic actuator including a coil and an attenuating circuit. The coil is arranged to be energized by a power source to switch the wedge clutch between: a locked mode in which the inner and races are locked in a circumferential direction and a free-wheel mode in which the inner race is rotatable with respect to the outer race in the circumferential direction. The attenuating circuit includes a capacitor parallel with the coil and a switch wired to the capacitor. During the free-wheel mode: the switch is arranged to connect the capacitor to an electrical ground; and the electrical power source is arranged to energize the coil and charge the capacitor with a voltage. Following initiation of the locked mode: the switch isolates the capacitor from the electrical ground; and the capacitor discharges the voltage through the coil.

An example electromagnetic clutch assembly includes a rotatable portion and a stationary portion. The rotatable portion includes a field winding and a clutch body, and the stationary portion includes an exciter winding that is inductively coupled to the rotatable portion and is operable to energize the field winding. The field winding is operable, when energized, to provide a magnetic field that causes engagement or disengagement between the clutch body and an armature body. A method of operating an electromagnetic clutch assembly is also disclosed.

Provided is an electromagnetic clutch capable of shortening, even in a low temperature atmosphere, the fuse reaction time from when a rotating shaft is locked, while preventing or suppressing malfunction of the thermal fuse. An electromagnetic clutch 1 is equipped with a rotor 2, an armature 3, an electromagnetic coil unit 4, a thermal fuse 5, and a thermally actuated switch 6. The thermally actuated switch 6 is connected in series to an electromagnetic coil 41 of the electromagnetic coil unit 4 along with the thermal fuse 5. When a temperature of the thermally actuated switch 6 exceeds a switching temperature (predetermined temperature) Ts, the thermally actuated switch 6 is displaced in an electric power supply OFF direction, and thereafter, it is displaced in an electric power supply ON direction due to a reduction in temperature. The thermally actuated switch 6 turns ON/OFF the electric power supply to the electromagnetic coil 41 such that the thermal fuse vicinity temperature T1 does not exceed the operational temperature Tf of the thermal fuse 5 due to self-heating of the electromagnetic coil 41 itself generated by the electric power supplied to the electromagnetic coil 41, thereby preventing malfunction of the thermal fuse 5 due to self-heating of the electromagnetic coil 41.

A transmission control unit for a wedge clutch, comprising a controller configured to send one or more signals to a switch connected to the wedge clutch, the switch being configured to demagnetize the wedge clutch by sending current in a first direction to a coil of the wedge clutch.

A fishing machine includes a rotary drum for winding a fishing line, capable of rotating in a reeling direction and in a unreeling direction, a drive motor for rotating the rotary drum in the reeling direction and in the unreeling direction, and an electromagnetic clutch for transmitting the rotation of the drive motor to the rotary drum. The electromagnetic clutch is capable of variably setting a transmitting torque of rotation, and the transmitting torque is set to a value for cancelling a mechanical load in the unreeling direction of the fishing machine.

An improved electromagnetic clutch for use in a riding lawnmower or similar vehicle is provided. The clutch comprises a coil assembly, a rotor assembly and a pulley assembly. The coil assembly comprises a shell, an encapsulated coil and a coil ring, the coil ring is pressed in the encapsulated coil, the encapsulated coil is inside of the shell, the extended piece of the shell has magnets and brake pieces. The rotor assembly comprises a rotor and a shaft, the shaft pressed in the rotor and is on the coil ring. The pulley assembly comprises a pulley, an armature and leaf springs, one side of the leaf spring is pressed on armature and the another side is pressed on pulley, the pulley is on the shaft, the location of the armature is between brake pieces and rotor. The encapsulated coil has thermal fuse inside and the thermal fuse electrical connected with coil wires, the electricity will be cut off when the temperature of encapsulated coil higher than the melting point of the thermal fuse caused by fitting incorrect or slipping happened during clutch working to protect lawnmower parts or avoid fire accident.

A drive force control system appropriately controls motors each connected to a corresponding one of drive wheels, so that a vehicle can be propelled with high efficiency. First motor and second motors are controlled in such a manner that a sum of torques transmitted to a right front wheel and a left rear wheel equals to a total value of required torques of the right front wheel and the left rear wheel. A target torque of the first motor and a target torque of the second motor achieving a smallest amount of power output from an electrical power source, for the output torques from the first motor and the second motor are calculated. A torque is generated by the first motor based on the target torque of the first motor calculated, and a torque is generated by the second motor based on the target torque of the second motor calculated.