Assembly of rolling bearings
Rolling bearing is a kind of precision mechanical element. Its working principle is to change the sliding friction generated by the relative motion between the shaft and the shaft seat into rolling friction, so as to achieve the effect of reducing friction. This kind of bearing usually includes four parts: inner ring, outer ring, rolling element and cage.
Rolling bearings should be thoroughly cleaned before assembly to ensure that there is no dirt in the bearing position. During assembly, apply a layer of lubricating oil on the surface of the mating parts, and make the bearing end without model face the inside, close to the shaft shoulder. The tool used for assembly must be a special press, and it is not allowed to strike simply and roughly. The size, direction and action position of the force used by the sleeve bearing should be appropriate to avoid excessive force on the protective frame or rolling element. The force should be uniformly and symmetrically stressed to ensure that the end face of the bearing is perpendicular to the shaft.
The inner ring end face of the bearing should be assembled close to the shaft shoulder. After the outer ring is assembled, the contact between the bearing cover at the positioning end and the washer or outer ring should be as uniform as possible. During the assembly process, we must follow the requirements of drawings and processes, especially the axial clearance of single row tapered roller bearings, thrust angular contact bearings and two-way thrust ball bearings, and there must be no deviation from the requirements. If it is found that the fit between holes or shafts is too loose or tight, it must not be forcibly assembled. Check the tolerance, analyze the cause of the problem, and then deal with it accordingly.
After the rolling bearing is assembled, inject an appropriate amount of grease into the bearing with grease and its matching surface. At this time, we must pay attention to the working temperature of the bearing and select the matching grease type. Observe whether the rotation of the relative moving parts is flexible and light. If there is any stagnation, check and analyze the cause of the problem and deal with it accordingly.
Assembly of linear bearing
Linear bearing is a motion system used for linear travel and in conjunction with cylindrical shaft. Because the bearing ball of this kind of bearing is in point contact with the bearing sleeve, the rolling of the steel ball can obtain the minimum friction resistance. Therefore, the friction of linear bearing is small, and its stability is quite good.
Before assembling linear bearings, grease should be applied inside the bearings. During the assembly process, a special installation tool should be used to press the end face of the outer ring of the bearing into the support seat. During the pressing process, the two cannot rotate relatively, so as to avoid the deformation or damage of the bearing. The fit between the bearing and the support seat must meet the tolerance requirements, and cannot be too loose or too tight. Too loose will make the bearing unable to be fixed in the support seat, too tight will make the guide rail shaft and the bearing interference fit, causing damage to the bearing.
In addition, when installing the guide rail shaft into the bearing, it should be gently inserted in the center of the bearing. If the insertion is not straight or the force is uneven, the ball will fall off and the cage will be deformed. It is also not allowed to use the set screw to tighten directly on the outer ring of the bearing, otherwise deformation will occur.