The size of the vibrating screen eccentric shaft is calculated from the crushing force. When the journal of the eccentric shaft at the rack bearing and movable jaw bearing is initially determined, the bearing specifications are initially determined based on this. Generally, the medium wide series specifications are selected as far as possible to check the theoretical service life of the bearing to meet the relevant standards.
Bearing accuracy includes dimensional tolerance and rotation accuracy. Whether it is the geometric tolerance of each component of the bearing or the radial and axial runout errors during rotation, because the jaw crusher moves at a spindle speed of less than 300r/mim, ordinary precision bearings can meet the requirements.
Bearing internal clearance:
Spherical roller bearings only have radial clearance, which is divided into five groups according to the standard, and has been selected and adjusted by the manufacturer before leaving the factory. After the bearing is assembled, its original clearance will be reduced. For moving jaw bearing, the eccentric shaft is assembled with it by interference fit. After heated, the inner ring of the movable jaw bearing is expanded and installed on the eccentric shaft. However, after several times of such treatment, if the journal size decreases by 5% compared with the original size, turning is not allowed, and the shaft should be replaced.
- Before installation, check whether there is rust, if any, clean it with diesel or kerosene. Then check whether the radial clearance, inner hole size and accuracy, eccentric shaft assembly journal size, etc. of the bearing meet the requirements.
- Because the journal interference of the bearing is large (to the maximum extent that it can accommodate or withstand), the hot assembly method is generally used for installation. The assembly can only be carried out after the shaft hole expands to more than the journal size. The hot charging method uses oil bath for heating, which can ensure that all parts of the bearing are heated evenly without deformation or hardness reduction.
- After the bearing is assembled, wait for it to completely cool down, and then check the radial clearance of the bearing with a feeler gauge.If the cause cannot be found, it must be disassembled and reassembled. If the clearance is appropriate, apply grease and then assemble other parts.
Because the operating conditions of the bearing are very poor, the working environment is high in humidity, dust particles, high speed, high temperature, and accompanied by high intensity of vibration and impact, the workload is huge. Therefore, a good shale shaker bearing must have the characteristics of strong bearing capacity, good impact resistance and good lubrication performance.