Jaw crusher is the most widely used crusher equipment in all walks of life, for breaking all kinds of different hardness, different types of materials, so the jaw crusher in the job process, inevitably there will be overload. This requires that the equipment itself should have good self-protection system, to make the device safe operation, the failure rate remained at a low level.
jaw crusher is extremely harsh operating conditions, volatile workload, peak load is usually more than three times the average load. Often due to uneven or because people feed the crushing chamber can not be broken into extremely hard strong material (such as iron, etc., hereinafter referred to as barrier material) and the sudden overload of substantial danger. To this end, more than jaw crusher overload protection with targeted measures, the development has mainly used the following methods.
(1)Break bracket : the low intensity of the bracket is easy to set break points, which appeared in the crusher overload, stress sensitive area because of the bracket rose sharply to limit the stress on their own to break, cut off the power transmission, to prevent machine damage.
This traditional overload protection measures, simple structure, easy to manufacture. However, due to elbow plate (usually cast iron) the mechanical properties of volatile and subject to the limited accuracy of the calculation can not accurately quantify the control break points, the actual application is often overloaded and lack of protection. Moreover, even if the overload has been protected, but because of broken machines in the accident state, cleaning up, dismantling and replacement parts before the machine is not running, this process will inevitably cause disruption, delay production.
(2) Moment limit protection: The spring friction clutch, hydraulic friction clutch or a safety pin and so on. Such methods in the simple pendulum jaw crusher to apply more.
Torque friction clutch work: M = fN where N is the disc springs and clamping force between the clutch; f the disc spring and the friction between the clutch factor.
This clutch is necessary to ensure the transmission of torque to work, but also the transfer of torque does not exceed the allowable value. When the fall crushing chamber barrier material, the machine overload reaches a critical torque, the flywheel is free to slide in the axis of BU, the main components of the protective effect. However, due to the clutch friction factor / affected by external conditions (such as temperature, etc.) a greater impact to the reliability of the restrictions, and overload, still human clearance, stop repair, system recovery is too much trouble.
(3) Hydraulic jaw crusher protection: As the aforementioned two kinds of methods exist for the protection overload protection under accident conditions is not reliable and need to stop treatment, resulting in disruption and recovery process more difficult issues, with more material in the crushing process flow barrier material (such as slag broken line), are often unable to meet production needs. Therefore, the development of safe and reliable hydraulic protection device to replace the traditional passive means of protection as possible to ensure a smooth continuous machine safety operation is particularly necessary.