A door armrest of a vehicle is provided in a door trim that forms a door for opening and closing a door opening formed in a vehicle body, and the door armrest may include an armrest portion on which an occupant's arm is supported and which may be provided on an internal side of the door trim and slides in a longitudinal direction of the vehicle body, and a motor driving portion mounted below the armrest portion, and configured to drive the armrest portion to selectively slide according to an opening or closing signal of the door.

A door armrest of a vehicle is provided in a door trim that forms a door for opening and closing a door opening formed in a vehicle body, and the door armrest may include an armrest portion on which an occupant's arm is supported and which may be provided on an internal side of the door trim and slides in a longitudinal direction of the vehicle body, and a motor driving portion mounted below the armrest portion, and configured to drive the armrest portion to selectively slide according to an opening or closing signal of the door.

A power tool is provided having a motor and a motor shaft, wherein a fan wheel in the power tool is designed to generate an air flow for cooling the motor. The power tool provides a coupling formed magnetically between the fan wheel and the motor shaft such that the motor shaft drives the fan wheel in a rotary movement with a speed that is less than a speed of the motor shaft. As a result of the magnetic coupling of the fan wheel and motor shaft, the movements of the two components can be decoupled from one another such that an increase in the rotational speed of the motor shaft does not also result in an increased speed at the fan wheel. As a result, fan losses can be considerably reduced and the efficiency of the motor of the power tool can be significantly improved. A method is also provided for cooling a motor of a power tool, wherein there is a magnetic coupling between a fan wheel and a motor shaft of the power tool.

A drive transmitter includes a connector, an electromagnetic clutch, a shaft, and a restriction member. The electromagnetic clutch includes the connector as a single unit. The shaft serves as a rotation axis of the electromagnetic clutch. The restriction member restricts a position of the connector in an axial direction of the shaft.

An electrostatic clutch is described comprising a plurality of micron-scale thickness electrodes, adjacent electrodes being separated by a thin film of dielectric material. A power source and controller apply a voltage across two electrodes, causing an electrostatic force to develop. When engaged, a force can be transferred through the clutch. A tensioning device maintains the alignment of the clutch when the electrodes are disengaged, but permits movement in at least one direction. In some embodiments, multiple clutches are connected to an output to provide variable force control and a broad range of torque input and output values. Moreover, the clutch can be used as an energy-recycling actuator that captures mechanical energy from negative work movements, and returns energy during positive work movements.

An electrostatic clutch is described comprising a plurality of micron-scale thickness electrodes, adjacent electrodes being separated by a thin film of dielectric material. A power source and controller apply a voltage across two electrodes, causing an electrostatic force to develop. When engaged, a force can be transferred through the clutch. A tensioning device maintains the alignment of the clutch when the electrodes are disengaged, but permits movement in at least one direction. In some embodiments, multiple clutches are connected to an output to provide variable force control and a broad range of torque input and output values. Moreover, the clutch can be used as an energy-recycling actuator that captures mechanical energy from negative work movements, and returns energy during positive work movements.

Disclosed is a plastic composite including a magnetic alloy material in an amount of about 20% by volume or greater on the basis of the total volume of the plastic composite. Accordingly, weight of the clutch may be reduced by about 0.4 kg and weight of the pulley can be reduced by about 0.4 kg with the result that overall weight may be reduced by about 0.8 kg.

Disclosed is a motor having a clutch function. The motor having the clutch function includes a driving unit, a reduction gear unit configured to reduce a rotational speed of the driving unit, and a clutch unit connected between the driving unit and the reduction gear unit and configured to selectively block power transmission, and the clutch unit includes an inner race connected to the driving unit and having a clutch shell; an outer race configured to output a torque of the clutch shell; a plurality of rollers provided in a circumferential direction between the clutch shell and the outer race, and configured to transmit the torque; an armature configured to rotate with maintaining an interval between the plurality of rollers; and a solenoid configured to block the torque input from the outer race to the inner race by controlling the rotation of the armature.

A switchable clutch includes an outer ring, an inner ring, a roller cage, a plurality of rollers, and a drag plate. The outer ring includes a plurality of ramped surfaces. The roller cage is disposed radially between the outer ring and the inner ring. The rollers are guided by the roller cage. The drag plate is rotationally fixed to the inner ring and is engageable with the roller cage to rotate the rollers relative to the outer ring. In an example embodiment, the switchable clutch has a spring engaged with the outer ring for urging the roller cage in a first rotational direction relative to the outer ring. In an example embodiment, the switchable clutch has an electromagnet for engaging the drag plate and the roller cage and/or a coil spring assembly for disengaging the drag plate and the roller cage.

An apparatus for coupling mechanical power between the rotor of a Brushless DC Motor and an external mechanical load comprises: a) two concentric rings; b) an equal number of magnets connected to the inner ring and to the outer ring; and c) an opposite orientation of the poles of each couple of facing magnets, wherein one magnet is placed on the inner ring, and its facing magnet is placed on the outer ring; wherein the first of said two concentric rings is rotatable around an axis by the application of a force not applied by the second ring, and wherein when said first concentric ring rotates, the second ring rotates as well by the action of magnetic forces.