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Some introduction about brake

Issuing time:2020-11-14 15:55Author:宁波中意液压马达

The working principle of the friction brake installed on the rotary reducer or motor used by the company is as follows:

When the control port does not enter the high-pressure oil, the compressed butterfly spring or coil spring force compresses the friction plate through the piston, causing friction between the friction plates to brake the brake shaft; when the control port When high enough high-pressure oil enters, it will push the piston to compress the butterfly spring or coil spring to loosen the originally compressed friction plates, so that the power generated by the motor is transmitted outward through the brake shaft. Brakes generally have two technical parameters, one is the opening pressure, and the other is the braking torque.

P=F/S, P is the opening pressure, F is the spring force, and S is the area of the piston. The area of the piston is basically determined during design and manufacture. Therefore, the change of the opening pressure is generally directly related to the force generated by the spring. The quality directly affects the opening pressure of the brake, so the spring can be said to be the most critical part of the brake. In general, it is difficult to detect the braking torque value when in use, so the opening pressure value will be checked to initially confirm whether the brake fails. Except for some special circumstances, the general opening pressure value is set between 2MPa-3MPa. If it is too low, when the customer system returns to a certain back pressure, it may offset the opening pressure, so that the opening pressure should be closed normally. The brake is half open or open. If it is too high, the spring is not fully compressed and the friction plate is not fully opened when the customer uses it with no load or low load. Therefore, the brake may make abnormal noises during use. One of the reasons for the use of two-way balancing valves for rotating and rotating conditions.

The braking torque is related to the friction coefficient of the friction lining, the pressure on the friction surface, the total friction area, the equivalent friction radius, and the number of friction surfaces. The number of friction surfaces and the size and diameter of the movable stator have been determined during design and manufacturing, so the general impact The braking torque is the spring force and the friction coefficient of the friction plate. Different friction materials are used, and the coefficient of friction varies greatly. Generally, there are paper-based, copper-based, steel-to-copper, etc. Paper base is relatively easy to wear, copper base has a small relative friction coefficient, copper is easy to deform and wear due to its low hardness. Generally, square or arc-shaped grooves are provided on the moving plate of the friction plate to facilitate the storage of oil for lubrication and to extend the service life of the friction plate. Special attention should be paid to the fact that the friction plate generally has a permissible specific pressure requirement, which is to prevent the friction plate from being fractured when the pressure is too high. In construction machinery, there are many working conditions that require brakes, such as the rotation of the pump truck, the rotation of the truck crane, the lifting conditions, etc. These not only require the brake to provide a braking effect during the process of rotating hoisting to parking. When the machine is driving and turning, due to the existence of inertia, the brake is also required to lock the swing arm. Regardless of a few springs, a few friction plates, a small qualified brake, it plays the role of a foot brake and a hand brake in a car.