A motor assembly that includes a motor (102) having a rotatable shaft, a hub coupled to the rotatable shaft, the hub having a propeller indexer to receive a propeller (104), when the propeller is present, a sensor trigger rotatable with the shaft (100) and positioned at a propeller offset angle ?.sub.PROP from the propeller indexer, and a sensor coupled to the motor and positioned to detect the sensor trigger so that the propeller indexer may be positioned at the propeller offset angle ?.sub.PROP from the sensor through rotation of the shaft so that said sensor is proximate to the sensor trigger.

A motor control device for a machine tool having a plurality of axes includes a plurality of motor control units that control motors; an abnormality detection unit provided for at least one of the motor control units and configured to output an abnormality detection signal upon detecting an abnormality with respect to the axis driven by the motor controlled by the motor control unit provided with the abnormality detection unit; a safety operation control unit provided for a motor control unit that is not the motor control unit provided with the abnormality detection unit, the safety operation control unit configured to control the motor upon receiving the abnormality detection signal in such a way that the tool comes out of contact with the workpiece; and a communication unit that transmits the abnormality detection signal outputted by the abnormality detection unit to the safety operation control unit.

Provided is a motor controller including: a rotation control unit configured to control a rotation of a motor; a brake control unit configured to control an operation of a brake for holding a rotor with respect to a stator of the motor; a rotation-state detection unit configured to detect a rotation state of the motor; a timer configured to measure, in a released state where an operation of the brake is released by the brake control unit, a time from an outputting of a command to change over a state of the brake to a locked state to a detection of a predetermined change in a rotation state of the motor by the rotation-state detection unit; and a determination unit configured to determine that a brake operation delay abnormality is present when the time, measured by the timer, is equal to or more than a predetermined threshold.

Techniques are described for using an electrical motor to slow down or stop a propulsor during an operation mode where the engine is to be otherwise running but the speed of the propulsor should be low or the propulsor should be stopped.

A spring return throttle actuator including: an electric, plural-coil DC motor having an output shaft, a throttle return spring, a gear transmission connected to the output shaft, a control unit adapted to control power supply to the DC motor, wherein the spring return throttle actuator has a movement range between closed throttle and opened throttle. The control unit is arranged to short-circuit at least two DC motor coils in order to create a DC motor return resist torque, and the control unit includes a movement monitoring circuit being arranged to monitor actuator movement forced by the throttle return spring and resisted by the DC motor return resist torque. The invention also relates to a method and a throttle assembly.

A device for expanding steam, whereby this device comprises an expander with an inlet that is connected to an inlet pipe and an outlet that is connected to an outlet pipe, whereby the inlet pipe is provided with an inlet valve and the outlet pipe is provided with an outlet valve for isolating the space between the valves, by closing these valves when the expander is not operating, whereby the device is provided with a steam supply that conditions the space between the valves when the expander is not operating, such that no air can penetrate into the space.

A control device for a linear motor includes a speed controller that calculates a current command value by an integration operation using a first integral value of a difference between a moving speed of a movable element provided in the linear motor and a speed command value calculated on the basis of a position command value, a current controller that applies a voltage to the linear motor on the basis of the current command value, and a correction value storage unit that stores the first integral value of the speed controller when the movable element remains at a position indicated by the position command value. When resuming control of the linear motor, the speed controller sets the first integral value stored in the correction value storage unit as an initial value for the integration operation before the brake controller turns off the brake device.

The electric-powered actuator includes a control device including: a motor angle estimation unit, and a reverse-input holding control section having a function of engaging an engaging part with an engaged part by controlling a solenoid to set the reverse-input holding mechanism into a reverse-input holding state while the electric-powered actuator is applying a load and a function of, from the reverse-input holding state, disengaging the engaging part from the engaged part to set the reverse-input holding mechanism into a reverse-input holding release state. The reverse-input holding control section includes an engagement intermediate control function section configured to control the estimated rotation angle such that the engaged part and the engaging part come into a predetermined positional relation within a certain period of time, when the engaging part is brought into engagement with the engaged part and when the engaging part is brought out of engagement with the engaged part.

The motor control device is an electric motor control device including a control unit (control circuit unit) configured to output a forward-rotation command or a reverse-rotation command to the electric motor. The control unit includes a position detector (door opening/closing information generation circuit) configured to detect a rotation direction of the electric motor when a detection signal is input from a rotation sensor (Hall integrated circuit (IC)), which detects the rotation of the electric motor, while no current is supplied to the electric motor. The control unit includes an electric current supply device (pulse width modulation (PWM) command generation circuit) configured to supply an electric current by which the electric motor is rotated in an opposite direction to the detected rotation direction by increasing an electric current supply duty ratio every time the detection signal is switched.

Methods and systems include an actuator adapted to provide drive power and hold power to an external device. A motor provides for driving the external device to a determined position when the motor is energized. A switching circuit is configured to energize the motor with a high voltage to drive the external device to the determined position and energize the motor with a low voltage to hold the external device in the determined position.