Abstract:
An electromechanical actuator is adapted to be connected to an external device for displacing the external device to a predetermined position and maintaining the external device at that position. The actuator includes a housing which holds a drive motor for driving the external device to the predetermined position when the motor is energized and a brake mechanism for maintaining the external device at the predetermined position when the brake mechanism is activated. A switching device generates switching signals for energizing the motor to drive the external device to the predetermined position and for de-energizing the motor and activating the brake mechanism when a predetermined time has passed from a moment the drive motor is energized, to maintain the external device at the predetermined position.
Abstract:
A lock device for an output shaft, wherein an output shaft is formed by connection of a driving shaft and a driven shaft, a play angle for not transmitting power for a specified angle in mutual rotating directions is formed in the connection area for connecting the driving shaft and driven shaft, a locking mechanism for locking by moving a lock member arrested on the driven shaft and held movably inward and outward in the radial direction is provided at the driven shaft side, and an unlocking mechanism for unlocking by moving the lock member of the locking mechanism in an unlocking direction within the rotating amount of the play angle is provided in the driving shaft.
Abstract:
A hydraulic emergency control for a gear-ratio-dependent change in hydraulic fluid pressures in a first and second hydraulic bevel-gear axial adjuster of a continuously variable transmission (10), is provided in which a pump (1) supplies at least the piston chamber (17) of the second axial adjuster, and at least one downstream pressure limiting valve (40) limits the fluid pressure there and moreover from this supply, via a continuous path valve (20), supplies the piston chamber (13) of the first axial adjuster, and the continuous path valve (20) is controlled with the aid of a pressure differential acting on a throttle valve (39) that is downstream of the pump (1) and is integrated with a switching valve (30). The switching valve (30', 30", 30'"), the continuous path valve (20', 20"), and the pressure limiting valve (40', 40", 40'") are each hydraulically triggered via at least one of a plurality of pilot control valves (120, 120'), (140, 140'), (160, 160') and (170, 170') counter to the action of a mechanical or hydraulic actuator disposed on the corresponding controlled valve. With the aid of the pilot control valves, among other things the switching valve is hydraulically controlled in such a way that it detects the control failure from control pressure changes in the system and switches over to an emergency operation mode.
Abstract:
The device for braking an electric drive motor of a hand-held working tool has a safety brake for an immediate stopping of the working tool and an independent mechanical brake for coasting the working tool to a stop after switching off the drive motor. The mechanical brake acts on a rotational part connected to the drive motor and is activated when a switch element for activating the drive motor is released.
Abstract:
A drive motor comprises a motor body (5) for rotating a motor shaft (11) in a predetermined forward direction; a brake engagement surface (30) formed at a projection (14) which is projected from a part of the motor shaft; claw piece (15) which engages with the projection at a predetermined position on interruption of electricity for the motor body and acts to stop rotation of the motor shaft, wherein the claw piece comprises an engagement claw (60) of actue angle shape; and a wedge engagement release mechanism (31) for releasing the wedged engagement by rotating the motor shaft in a release direction which is equal to the reversed direction.
Abstract:
A brake for a motor, particularly an alternating current motor with an electromagnetic brake is proposed for improving dynamic characteristics without increasing power loss, in which a brake magnet coil is subdivided at an intermediate tap into two partial coils, one of which is arranged in a freewheeling circuit.
Abstract:
The drive arrangement suitable especially for a hoist mechanism comprises a pole-changing two-speed three-phase motor which is united into one construction unit with a friction brake which can be released by an electromagnet. The two three-phase field windings dimensioned for different pole numbers are connected in star circuit arrangement and have star points conducted out at the motor terminal box of the three-phase motor. The electromagnet of the friction brake is connected through a rectifier circuit arrangement to the star points and when the three-phase motor is switched on is energized by the differential voltage then occurring between the two star points for the release of the friction brake. The rectifier circuit arrangement is accommodated, together with a controllable switch likewise connected to the two star points in the motor terminal box, while the switch path of the controllable switch simultaneously short-circuits the electromagnet on the direct current side, in the switching off of the three-phase motor. The friction brake of the drive arrangement in this way can be controlled from a remotely situated switch or control box containing a direction contactor and a speed contactor, without additional connecting leads being necessary for this purpose beyond the connecting leads in any case necessary for the operation of the three-phase motor.The arrangement is also suitable in corresponding manner for delta-connection three-phase motors.
Abstract:
An elevator control apparatus includes a brake having a brake coil which is energized in response to a start signal to release the braking force exerted by the brake. A current sensor detects the current flowing through the brake coil and generates an actuating signal when the brake coil current changes due to the brake being released. The actuating signal causes a drive circuit to supply current to a motor for driving an elevator cage. As a result, the elevator cage can be smoothly started.
Abstract:
A method and device for checking the brake of a motion-controlled and monitored printing press drive motor includes a processor unit which is connected on its input side to a motion signal generator and a motion control panel, and is connected on its output side with the drive motor and associated motor brake via a power output stage which is configured as a power converter. The processor unit generates the control signals for the motor and brake. Before each starting operation and with the brake still applied, a momentary small nominal power motion value is fed as a test value to the drive motor and subsequently the actual motor motion values are measured. If actual motion is detected, the brake torque is not sufficient, the system generates an error message and it switches the drive motor off. If no motion is detected, the motor brake is released, the nominal power value is maintained and the motion of the drive motor is re-checked. If motion still does not take place, the motor brake has not released properly, whereupon the system generates an error message and stops the drive motor. If motion is >.vertline.0.vertline., the motor brake function check is completed and the drive motor is run up to the desired motion values.
Abstract:
Transportation apparatus, such as escalators and moving walks, having an electrically released, magnetically set brake, and a servo loop for regulating the brake coil current. Brake voltage and brake current feedback are both used in the regulation of the brake current, with the values of the voltage and current feedback being selected to cause electromagnetic flux produced by the brake coil current to substantially cancel the magnetic flux produced by permanent magnets over the operating temperature range of the brake. In a preferred embodiment of the invention, the brake current is pulsed continuously while the transportation apparatus is operated, to prevent transient excursions of the brake current from initiating and maintaining partial setting of the brake.