A sprag clutch has an inner race, an outer race, and a radial cavity between the races. A plurality of sprags are disposed in the radial cavity, and each sprag is configured to rotate about an axis of rotation that is perpendicular to its longitudinal axis. A sprag cage retains each of the plurality of sprags at a uniform spacing within the radial cavity, and a plurality of actuators are positioned to exert or withdraw a force upon a corresponding sprag.

A control system for controlling movements of an end effector connected to a clutch output of at least two magnetorheological (MR) fluid clutch apparatus, the control system comprises a clutch driver configured to drive the at least two MR fluid clutch apparatuses between at least a controlled slippage mode, in which slippage between a clutch input and the clutch output of the MR fluid clutch apparatuses varies, and a combined mode, in which said slippage between the clutch input and the clutch output is maintained below a given threshold simultaneously for both of the MR fluid clutch apparatuses, the two clutch outputs resisting movement of the end effector in the same direction. A motor driver is configured to control a motor output of at least one motor, the motor output coupled to at least one clutch input. A mode selector module is configured to receive signals representative of at least one movement parameter of the end effector, the mode selector module selecting a mode between at least the controlled slippage mode and the combined mode of the clutch driver based on the signals, and switching the selected mode based on the signals. A movement controller controls the clutch driver and the motor driver to displace the end effector based on at least one of the selected mode and on commanded movements of the end effector for the end effector to achieve the commanded movements.

A vehicle drive train, has a clutch unit actuatable by an actuating unit, and a sensor for determining the coupling status. The actuating unit includes an electromagnetic actuator having a piston movable from a starting to an end position. At least the piston and the clutch are acted on by a transmission fluid. Operating the drive train can include: a) actuating the actuator and moving the piston from the starting position; b) ascertaining a measured sensor value; c) ascertaining a temperature of the transmission fluid by measuring an electrical resistance of the actuator and/or measuring a first time interval between actuation of the actuator according to step a) and the detection by the sensor of an intermediate position that is reached by the piston; d) determining an actual position of the piston based on the measured sensor value and the temperature; and e) moving the piston, starting from the determined actual position, into the end position.

The invention relates to a method for determining the absolute position of a component of an actuator rotating about a rotational axis, in particular a clutch actuator, wherein the component has a co-rotating magnetic element (18), and the absolute position of the magnetic element (18) is detected by way of a multi-turn sensor (16) located opposite the magnetic element (18), which is supplied with a voltage. In a method, in which the absolute position can be detected without great constructional effort, a position of the magnetic element (18) is monitored by a Wiegand wire unit (19), which detects a movement of the component when the actuator (3, 12, 13) is turned off, and if a movement is detected, transmits a voltage pulse to the multi-turn sensor (16) for measuring the current position of the component.

A plurality of inductive loads (105) are connectable in parallel with one another between first and second terminals (120, 125), to which a controllable voltage (205) is applied. A method (300, 400) for operating the loads (105) includes the steps of detecting (305, 405) the connection of a previously non-energized load (105) between the terminals (120, 125); setting (310, 410, 435) the voltage (205) to a predetermined first value (210), and, after the lapse of a predetermined time interval (315, 415), adjusting the voltage (205) to a predetermined second value (215), with the second value (215) being lower than the first value (210).

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 clutch current control circuit may include as a circuit for controlling a current of a clutch connected to a compressor, a strain gauge, wherein a resistance value of the strain gauge is varied according to the movement amount of an Electric Control Valve (ECV) shaft; a switching element of performing a switching operation by comparing a gate-source voltage determined according to a change in the resistance value of the strain gauge and the threshold voltage, and allowing a flow of a first clutch current to generate by a first switching operation state; and a resistor connected in parallel with the switching element, and allowing a flow of a second clutch current to generate by a second switching operation state of the switching element.

The invention relates to a method for determining the absolute position of a component of an actuator rotating about a rotational axis, in particular a clutch actuator, wherein the component has a co-rotating magnetic element (18), and the absolute position of the magnetic element (18) is detected by way of a multi-turn sensor (16) located opposite the magnetic element (18), which is supplied with a voltage. In a method, in which the absolute position can be detected without great constructional effort, a position of the magnetic element (18) is monitored by a Wiegand wire unit (19), which detects a movement of the component when the actuator (3, 12, 13) is turned off, and if a movement is detected, transmits a voltage pulse to the multi-turn sensor (16) for measuring the current position of the component.

Disclosed are systems and methods for protecting an escrow clutch of a self-service terminal. The systems and methods may include actuating a motor of the self-service terminal to cause an escrow clutch of the self-service terminal to spin at a rate. As the clutch spins, a determination as to when a clutch slippage exceeds a preset slippage rate may be made. When the clutch slippage exceeds the preset slippage rate, the motor may be actuated to cause the escrow clutch to spin at a second rate. The second rate may less than the first rate.

A vehicle drive train, has a clutch unit actuatable by an actuating unit, and a sensor for determining the coupling status. The actuating unit includes an electromagnetic actuator having a piston movable from a starting to an end position. At least the piston and the clutch are acted on by a transmission fluid. Operating the drive train can include: a) actuating the actuator and moving the piston from the starting position; b) ascertaining a measured sensor value; c) ascertaining a temperature of the transmission fluid by measuring an electrical resistance of the actuator and/or measuring a first time interval between actuation of the actuator according to step a) and the detection by the sensor of an intermediate position that is reached by the piston; d) determining an actual position of the piston based on the measured sensor value and the temperature; and e) moving the piston, starting from the determined actual position, into the end position.