Analysis on the Causes of Vibration of the Bearing Seat of the Pinion Gear of the Ball Mill

Ball mills are the most widely used grinding machines in heavy industries such as power generation, mineral processing, chemical and building materials. It can grind materials of various hardness, and finally meet the requirements of process indicators. Our ball mill is mainly used for slurry preparation. Because it is the core equipment of the enterprise, it requires a higher operating rate. Vibration at the bearing seat of the pinion gear of the ball mill is an equipment failure that affects the normal operation of the ball mill.　　 There are many reasons for low-frequency vibration, and the vibration size and harm caused by each cause are also different, and there are many repair methods. Therefore, the main reason for the vibration must first be found out and the main contradiction method must be solved. Now combined with the transmission structure of the pinion bearing seat of the ball mill, the common causes and treatment methods of vibration are analyzed.　　1 Pinion gear bearing housing vibration caused by unbalance 　　(1) The gear (small, large) hole position is defective.　　(2) The inner diameter of the gear shaft is eccentric.　　(3) The gear material is defective and trachoma appears.　　(4) Partial wear of gear.　　(5) The inner steel ball driven by the large gear ring adheres to the material, causing imbalance.　　Although the above unbalance occurs at a high rate on rotating equipment, the impact of unbalance on the vibration of the pinion bearing seat of the ball mill is not great in actual work. 2 Vibration caused by coupling assembly with different shafts. There are three situations for coupling assembly with different shafts: radial deviation of the center lines of the two shafts; skew of the two shafts and the center line; deviation of the center lines of the two shafts at the same time And measure the axial and radial clearance of the coupling. Excessive deviations will cause additional loads on couplings, drive shafts and bearings, resulting in heat generation, vibration, wear, and even fatigue and fracture accidents.　　Adjustment measures: 　　 first measure the axial and radial clearance of the coupling. Second: Analyze what kind of situation the coupling misalignment belongs to. If skew and offset occur at the same time. Calculate the skew adjustment first, and then calculate the offset adjustment, because the skew adjustment affects the offset. Then adjust the coupling according to the calculated value.　　3 Vibration caused by unreasonable gear shaft assembly　　1. Pinion vibration caused by unreasonable side clearance and top clearance of large and small gears. First, check whether the side clearance and top clearance of the large and small gears meet the requirements. The side clearance and top clearance of gear transmission should be appropriate. A certain side and top clearance can compensate for gear manufacturing and assembly deviations, compensate for thermal expansion and form an oil film, and prevent jamming. But too large gap will cause shock. If the gap is too large or too small, it will cause additional load, increase the wear of the gear transmission, and even cause accidents. The commonly used method of measuring the gap is to use the lead method.　　 2. The pinion gear vibration caused by the unreasonable contact of the pinion tooth surface. The contact area of u200bu200bthe gear is expressed by the percentage of the total length and height of the tooth in the contact part of the two gears along the tooth length and tooth height. The normal contact surface should be evenly distributed on the working surface of the tooth. If the contact surface is small or the contact position is incorrect, the load will be concentrated and distributed, causing local wear and vibration. Now analyze the causes of the following tooth surface contact conditions and propose adjustment measures.　　 (1) Contact with bias in the same direction. Reason: The axes of the two gears are not parallel. Adjustment method: within the allowable range, scrape the bearing bush or adjust the bearing seat.　　 (2) Contact with different directions. Reason: The axis of the two gears is skewed or the tooth direction is deviated. Adjustment method: within the allowable range, scrape the bearing bush or adjust the bearing seat, or trim the gear teeth with the deviation of the tooth direction.　　(3) One-sided partial contact. Reason: The axes of the two gears are not parallel and skew at the same time. Adjustment method: within the allowable range, scrape the bearing bush or adjust the bearing seat.　　(4) The contact area gradually moves from one side to the other, and the period is the number of teeth of the large gear or the small gear. Reason: The reference end face of the large gear or the small gear is not perpendicular to the centerline of rotation. Adjustment method: If the deviation is within the allowable range, trim the tooth surface of the gear with deviation.　　(5) The tooth top contact. Reason: The center distance of the gear axis is large or the original tooth profile deviation of the gear processing or the diameter of the top circle of the gear blank is too large. Adjustment method: within the allowable range, adjust the axis and increase the center distance, otherwise trim the tooth surface.　　(6) The contact area gradually moves from the tooth tip to the tooth root, and the period is the number of teeth of the large gear or the small gear.　　 Reason: radial runout of ring gear. Adjustment method: trim the gear teeth with deviation within the allowable range.　　4 Vibration caused by loose bolts 　　The phenomenon of loosening is caused by loose bolts. Inspection method: check the fastening bolts of all transmission parts one by one to see if there is any looseness. Adjustment method: Check and tighten the connecting bolts of all transmission parts. When necessary, take measures to prevent loose bolts.　　5 Pinion bearing housing vibration caused by the vibration of the bearing itself 　　The wear of the bearing rolling elements causes the bearing to heat and vibrate. Solution: Check whether the axial and radial clearance of the bearing exceeds the standard, and whether the rolling elements are severely worn. Otherwise, the bearing should be replaced. After replacement, the bearing clearance must meet the assembly requirements.