MWZ250-315 DC Electromagnetic Drum Brake Hengyang Heavy Industry Has an Explosion-proof Certificate

Brake function:

A brake is a device that has the function of slowing down, stopping, or maintaining a stopped state of moving parts (or moving machinery). It is a Machine element that stops or decelerates the moving parts in the machine. Commonly known as brakes or brakes. The brake mainly consists of a brake frame, brake components, and control devices. Some brakes are also equipped with automatic adjustment devices for brake component clearances. In order to reduce braking torque and structural dimensions, brakes are usually installed on the high-speed shaft of equipment, but large equipment with high safety requirements (such as mine hoists, elevators, etc.) should be installed on the low-speed shaft near the working part of the equipment.

Electromagnetic brake is an electric device that relies on the electromagnetic attraction generated by the electromagnetic system to make the armature work externally. Due to the characteristics of convenient loading and unloading, good response performance, high reliability, and green environmental protection, inductive coil electromagnetic brakes for mechanical equipment are widely used in construction machinery. The fault mechanism is that the inductance coil is the main component of the electromagnetic brake and the root cause of the vast majority of faults. The important feature of the inductance coil in mechanical equipment is that it generates a strong induced electromotive force at the moment when the circuit is turned on or off, especially when it is turned off. This electromotive force is usually several to several hundred times the normal working voltage. Such high impulse voltage causes great damage to the electromagnetic brake itself and also has a significant impact on subsequent equipment. An inductive coil, in addition to having a certain amount of inductance L, also has parameters such as wire resistance R, core loss, and capacitance between turns and layers of the coil. The equivalent circuit of the actual inductance coil is connected in series with R and L, and all losses of the actual inductance coil are represented by the losses on R;

Using an equivalent capacitor C in parallel at both ends of the mechanical equipment inductance coil, it represents the inter turn and inter layer capacitance of the coil, as well as other distributed capacitance, to form the equivalent circuit of the actual inductance coil. When the contact disconnects the inductance circuit, theoretically, the current in the inductance is suddenly interrupted, and Counter-electromotive force will be generated at both ends of the inductance. Because the current change rate is very large at this time, the opposite voltage will be generated at both ends of the inductance, which tends to be infinite (in fact, it cannot be infinite). Assuming that the magnetic field energy stored in the inductance coil of the mechanical equipment during steady-state is W, the magnetic field in the inductance should continue to maintain the continuity of current I when the contacts just separate. At this time, I charges C, and when the breakdown voltage is exceeded, an arc is generated, which keeps the current in a continuous state. When the arc is pulled apart to a certain distance and extinguished, the contact opens. At this point, the self induced potential generated by the inductance coil will continue to maintain current conduction, forming an RLC series oscillation circuit. If this voltage is less than the breakdown voltage of the contact gap.