A mechanical brake for arresting movement of the output shaft of a linear electric motor, comprising a pivotally mounted plate having a space for receiving the output shaft of the motor; an electrically operated holding device contacting a free end of the plate and arranged to hold the plate in a condition to permit movement of the output shaft and to permit the plate to pivot to a jamming position; wherein the electrically operated holding device comprises a solenoid to control the movement of the plate.

A mechanical brake for arresting movement of the output shaft of a linear electric motor, comprising a pivotally mounted plate having a space for receiving the output shaft of the motor; an electrically operated holding device contacting a free end of the plate and arranged to hold the plate in a condition to permit movement of the output shaft and to permit the plate to pivot to a jamming position; wherein the electrically operated holding device comprises a solenoid to control the movement of the plate.

An electric motor-driven parking brake of a motor vehicle can be released in an emergency by applying emergency current from a parallel emergency current source to the motors controlling the parking brake. The direction of the emergency current is selected to reverse the motors, i.e., release the parking brake.

An electric motor-driven parking brake of a motor vehicle can be released in an emergency by applying emergency current from a parallel emergency current source to the motors controlling the parking brake. The direction of the emergency current is selected to reverse the motors, i.e., release the parking brake.

A method for monitoring the performance of a mechanical brake for a linear electromagnetic motor, the linear motor having a linearly moveable output shaft, comprising monitoring travel of the output shaft over the duration of actuation of the mechanical brake and comparing said travel with a predetermined travel threshold.

A method for monitoring the performance of a mechanical brake for a linear electromagnetic motor, the linear motor having a linearly moveable output shaft, comprising monitoring travel of the output shaft over the duration of actuation of the mechanical brake and comparing said travel with a predetermined travel threshold.

A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a controller. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of a plurality of phases of the motor and the DC bus. The controller is operable to command dropping of a brake through a passive delay circuit responsive to detection of an emergency stop condition for a load driven by the motor and reduce a voltage on the DC bus by dropping at least one phase of the AC power source and/or using a dynamic braking resistor prior to the brake physically dropping.

A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a controller. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of a plurality of phases of the motor and the DC bus. The controller is operable to command dropping of a brake through a passive delay circuit responsive to detection of an emergency stop condition for a load driven by the motor and reduce a voltage on the DC bus by dropping at least one phase of the AC power source and/or using a dynamic braking resistor prior to the brake physically dropping.

A control device controls non-excitation-actuated electromagnetic brake operation. The control device includes an electronic component having a characteristic that when an inter-terminal voltage of two electrodes is equal to or higher than a predetermined voltage, a resistance value is lower than when the voltage is lower than the voltage and a diode disposed such that a cathode is on a side having a higher potential than an anode. The coil in the non-excitation-actuated electromagnetic brake and the electronic component are connected in series to form a first series circuit, the first series circuit and the diode are connected in parallel, and the electronic component is connected in series with the coil provided in the non-excitation-actuated electromagnetic brake so as not to be conducted when the inter-terminal voltage is lower than the predetermined voltage, but to be conducted when the inter-terminal voltage becomes equal to or higher than the predetermined voltage.

In inverter control for supplying power to a motor, a power conversion device includes a temperature sensor for detecting a temperature of the inverter, a voltage sensor for detecting a voltage between terminals of a capacitor that smooths the voltage between terminals between the power source and the inverter, an inverter controller for controlling the inverter, a rotation speed sensor for detecting a rotation speed of the motor, an electric current sensor for detecting electric current supplied to the motor and a discharge determination instruction controller for giving an instruction for discharging electric charges accumulated in the capacitor, in which, control of reducing the rotation speed of the motor and discharge control of the capacitor are performed in accordance with the temperature of the inverter, the rotation speed of the motor and the electric current supplied to the motor.