For the jaw crusher, the moving jaw swinging eccentric shaft speed frequency from the decision. In a certain range, the eccentric shaft speed increases, jaw crusher corresponding increase in production capacity, however, when the swing jaw exceeds a certain limit, further increase speed, very slow increase in production capacity, and sometimes even reduced. The jaw crusher power consumption is rising rapidly due to the high speed of the eccentric shaft material crushing good time to discharge from the discharge port, but affected the production capabilities. To ensure the jaw crusher has the best ability to work reasonably determine jaw crusher eccentric shaft revolutions.

To obtain the jaw crusher eccentric shaft speed, can be used for the following two hypotheses: As long jaw itself not a very big swings, it is assumed for the translational motion moving jaw, clamp a constant angle; movable jaw away from the fixed jaw, we have broken material trapezoidal cross-section prism free fall by gravity. In order not to interfere with the discharge of materials, the material falls prism conditions must be met: movable jaw plate away time t, crushing the material must fall height should be h; when the jaw crusher eccentric shaft revolution, the movable jaw swing twice.

In theory, the highest production capacity jaw crusher, the result of the type and nature of the material is not considered broken jaw crusher type and other factors, therefore, only be used to roughly determine the speed of jaw crusher. Typically, crushing hard materials, the speed should take smaller; crushing brittle materials, the speed desirable bigger; larger size of jaw crusher, should be appropriately reduced speed to reduce vibration, save power consumption.

In fact, as the movable jaw plate jaw crusher initial idle stroke, the material is still in the compressed state, not immediately fall, therefore, the eccentric shaft speed should be higher than the value calculated on the formula of about 30% lower. jaw crusher speed of the eccentric shaft can be calculated according to the following empirical formula: For the feed mouth width B ≤ 1.2m, with: n = 310-145B; the feed mouth width B 1.2m, with: n = 160-42B.