Selection of bearing structure
The INA bearing type that can meet the rigidity required by the mechanical shaft system [When the bearing is under load, the contact part of the rolling element and the raceway will be elastically deformed. "High rigidity" means that the amount of deformation due to this elastic deformation is small.] In parts such as machine tool spindles and automobile final reduction gears, while increasing the rigidity of the shaft, it is also necessary to increase the rigidity of the bearing. Roller bearings are less deformed under load than ball bearings. Preloading the bearing (negative clearance) can increase rigidity. This method is suitable for angular contact ball bearings and tapered roller bearings.
Analyze the factors that make the inner ring and outer ring of the bearing relatively tilt (such as the deflection of the shaft caused by the load, the poor accuracy of the shaft and the housing or the installation error), and select the bearing type that can adapt to this use condition. If the relative tilt between the inner ring and the outer ring is too large, the bearing will be damaged due to internal load. Therefore, a bearing type that can withstand this tilt should be selected. Generally speaking, the allowable tilt angle (or aligning angle) increases in the following order: cylindrical roller bearings, tapered roller bearings, deep groove ball bearings (angular contact ball bearings), spherical roller (ball) bearings.
Assembling and disassembling frequency and method for regular inspection etc. When assembling and disassembling frequently, it is more convenient to use cylindrical roller bearings with separable inner and outer rings, needle roller bearings and tapered roller bearings. Tapered hole self-aligning ball bearings and tapered hole spherical roller bearings can be easily assembled and disassembled through the use of fasteners or withdrawal sleeves. The type of machinery is different, the use conditions of the bearings will be different, and their performance requirements are also different, but generally speaking, there are no less than two bearings used on a shaft. Moreover, in order to facilitate axial positioning, most of the bearings are used as fixed-end bearings, and the rest are used as free-end bearings. The following table lists the choice of fixed end and free end bearing structure.
When installing the bearing, the force should be uniform and not directly hammered. For example, if the interference is large, the bearing should be heated in an air heating furnace or oil furnace with automatic temperature control, and the heating temperature should be strictly controlled below 120°. 2. Bearings equipped with nylon cages can work continuously and stably at -40°-120° for a long time, and should not work for more than 4 hours at 150°, and the short-term temperature peak can reach 180°. 3. The warehouse where the bearings are stored should be clean, dry and not allowed to be stored in the same warehouse as the chemical products, the relative humidity should not exceed 65%, and the bearings are not allowed to be stored on the ground.
