Grinders are widely used in the pulverizing system of thermal power plants, but the vibration of the transmission shaft and the broken teeth of the small pinion have always been a headache for the safe production of the system. Our factory's pulverizing system was also plagued by these two defects recently, even affecting the supply of fuel to the unit. After several adjustments by the maintenance team, significant improvements were achieved, with the vibration of the transmission shaft dropping below 0.08mm.
Specific Measures:
The tooth clearance is one of the critical assembly parameters for gear drive systems. The regulations stipulate a clearance of 7.5-8.5mm for large and small gears. In actual production, after long-term operation, the large gear's tooth ring is subjected to stress and deformation, gradually changing from circular to elliptical. Consequently, the tooth clearance in some areas can even be below 6mm. During the adjustment process, the tooth clearance should be set to 8.5-10mm to minimize the impact caused by the tooth clearance, which can lead to overload and tooth breakage.
2. Insufficient tension in the large gear ring is also a significant cause of its deformation. In practical operations, in addition to increasing the bolt tension, the mating surfaces of the large gear ring are connected using a 10mm thick steel plate to enlarge the clamping surface, preventing deformation of the gear ring, ensuring consistent angular velocity between the main and driven wheels, and preventing the change in transmission ratio from causing inertial forces that lead to fatigue fractures.
3. Proper lubrication of drive shaft bearings is also a key factor in ensuring smooth operation. While traditional methods, such as regular, manual oiling, can ensure adequate lubrication, they are prone to over or under-lubrication. It is recommended to use mechanical timed and quantitative lubrication to ensure moderate lubrication, reduce vibration, prevent bearing wear and retainer cracking, and extend the service life.
