The application relates to the technical field of control, and provides an electromagnetic brake control apparatus. The apparatus includes: a power supply management circuit, a first switch circuit, a freewheeling diode and a first control output end and a second control output end used to connect with two ends of an electromagnetic coil of the electromagnetic brake; the power supply management circuit includes: a power supply input end, a first output end and a second output end used to connect with an external power supply; an input end and an output end of the first switch circuit are respectively connected with the first output end and the first control output end, the first switch circuit is configured with a pulse width modulation function; a cathode and an anode of the freewheeling diode are respectively connected with the second output end and the first control output end.

An access control system for restricting access through a passageway includes a shaft rotatable about a central axis; a barrier fixed to the shaft to rotate therewith; and a brake assembly. The brake assembly includes a sun gear rotatable about the central axis, a carrier, and a ring gear, wherein one of the carrier or the ring gear is fixed against rotation and the other of the carrier or ring gear is connected to the shaft to rotate therewith. A plurality of planet gears are rotatably connected to the carrier, each planet gear being disposed between and engaging with each of the sun gear and the ring gear. The armature of an electromagnetic brake comprising an electromagnet and an armature is connected to or integral with the sun gear to rotate therewith. At least one of the electromagnet or the armature is moveable between an operative and an inoperative position.

Aspects of the disclosure provide an electric actuator including a first driving source coupled to an output through a first pathway created by a transmission, a second driving source coupled to the output though a second pathway created by the transmission that, upon the electric actuator losses electrical power to the electric actuator, causes the output to be positioned at a fail-safe position, a differential coupled to the first driving source and the second driving source through a third pathway created by the transmission to store energy from the first driving source in the second driving source, and an eddy current brake coupled to the output through the transmission that reduces a speed at which the second driving source moves the output to the fail-safe position.

An actuator unit (28) for a positively locking, switchable clutch or a brake comprises a shaft (18) which can be rotated with respect to a rotational axis (26), an actuator slide (30) for actuating the freewheel, wherein the actuator slide (30) is rotationally connected to the shaft (18) and can be moved relative to the shaft (18) in the axial direction between a first position and a second position, and an actuator (32) which is stationary at least in part and which moves the actuator slide (30) between the first position and the second position. The actuator (32) comprises a coil (42) which is stationary and which, in the energized state, generates a magnetic field, by way of which the actuator slide (30) can be moved out of the first position into the second position or vice versa. The coil (42) is not energized in the first and in the second position, wherein the actuator (32) fixes the actuator slide (30) in the first position and the second position. Also disclosed is a positively locking, switchable clutch or a brake for a motor vehicle drive train, with an actuator unit (28).

A carrying device and, a fixing method of a carrying device are provided. The carrying device includes a body and an electromagnet fixing module disposed on the body; wherein the electromagnet fixing module is configured to fix the carrying device. The present application uses the electromagnet fixing module to fix the carrying device, which can avoid downtime of an exposure machine caused by shaking of the carrying device when a robot arm of the exposure machine picks or places the mask form the carrying device so as to improve throughput.

An electromagnetic braking system and control method, with the system having a CCU, a braking cylinder, a push rod, an electromagnetic braking ring, an electromagnetic braking piston fixed to the push rod, a first shading plate and a second shading plate, a photoelectric sensor fixed near the push rod, and an electromagnetic braking control circuit, and the control method including following the steps: initial estimating of the braking distance (l) according to the current magnitude, electromagnetic force between the two electromagnetic coils and initial velocity (v) of the push rod, arranging a restoration distance (Δl) between the top dead center and the piston after braking, installing two shading plates and the photoelectric sensor; and setting the distance between the two electromagnetic coils to when the starts braking.

The present invention discloses a brake-by-wire actuator based on motor-magnetorheological fluid clutch. The system includes a motor, a transmission mechanism and a floating-caliper disc mechanism. The transmission mechanism includes a magnetorheological fluid clutch, a planetary gear set and a ball screw set. The ball screw set includes balls, a ball screw and a sleeve. The floating-caliper disc mechanism includes a brake pad back plate, left and right brake pads, a caliper body, a brake disc and a guide rail. The motor and the magnetorheological fluid clutch cascaded in series, the linear motion of the sleeve of the ball screw set is achieved by the magnetorheological fluid clutch and the transmission mechanism. The sleeve pushes forward the brake pad back plate of the floating-caliper disc mechanism to clamp the brake disc by left and right brake pads, which accomplishes braking. The present invention uses a brake-by-wire actuator based on motor-magnetorheological fluid clutch, which not only has the advantages of fast response and improved braking security, but also solves the problem of the motor stalling during long time braking.

A resistor includes an elongated cylindrical body having nodes and elongated members. The elongated members interconnect the nodes to form openings between the nodes and the elongated members for the flow therethrough of a cooling fluid. The body is configured to receive electric current from a powered system and to conduct and provide electric resistance to the electric current to dissipate at least part of the electric current as heat from the body. The body also is configured to be coupled with at least one other resistor of the powered system in one or more of a parallel or series arrangement in an electric circuit.

The present invention discloses an electromagnetic braking system and control method, the system comprises a CCU, a braking cylinder, a push rod, an electromagnetic braking ring, an electromagnetic braking piston fixed to the push rod, a first shading plate and a second shading plate, a photoelectric sensor fixed near the push rod, and an electromagnetic braking control circuit.

The control method includes following steps: initial estimating the braking distance l according to the current magnitude, electromagnetic force between the two electromagnetic coils and initial velocity v of the push rod, arranging a restoration distance Δl between the top dead center and the piston after braking, installing two shading plates and the photoelectric sensor; setting the distance between the two electromagnetic coils to L=l+Δl when starting the braking.

An excitation operation brake includes a braking shaft, an armature that rotates integrally with the braking shaft, and a field core including a disc portion facing the armature. The disc portion includes an outer magnetic shielding portion and an inner magnetic shielding portion, which make a magnetic flux flowing through the disc portion bypass to the armature a plurality of times. The outer magnetic shielding portion includes a low-magnetic resistance path having a magnetic resistance smaller than the magnetic resistance of a magnetic path that bypasses to the armature.