1. Installation of rolling bearings

A. Preparation before installation

The installation of bearings requires a clean and dry workplace. Especially for miniature and small bearings, if dust enters, it will greatly affect the characteristics of the bearings. Therefore, it is best to do it in a clean room. The bearings need to be unpacked before installation. Usually, in the case of grease lubrication, the rust inhibitor can be installed directly without cleaning; if oil lubrication is used, or grease lubrication is used, but the grease is mixed with the rust inhibitor, which will reduce the lubricity, it must be cleaned with gasoline or kerosene and dried before use. Bearings with dust covers on both sides or with sealing rings cannot be cleaned. Before installation, the machining quality of the matching surfaces of the shaft and the housing, the end faces of the bosses, the grooves and the connection surfaces should be carefully checked. All matching connection surfaces must be carefully cleaned and burrs removed, and the unprocessed surfaces of the castings must be cleaned of the molding sand. Do not unpack the bearings before the installation preparation work is completed to avoid contamination.

B. Installation of cylindrical bore bearings

(1) Press-in method

For small bearings with cylindrical inner bores that must be interference fit with mating parts, the bearings can be installed on the shaft or housing by mechanical or hydraulic methods, as shown in Figure 1. The installation pressure should be applied directly to the end face of the bearing ring with interference fit. It is not allowed to apply pressure to the non-interference fit ring by rolling to transmit pressure, otherwise it will cause pressure damage on the working surface of the bearing, causing the bearing to break quickly. If the bearing ring is interference fit with the shaft and the housing hole, the inner and outer rings of the bearing should be pressed into the shaft and housing at the same time during assembly, as shown in Figure 2. At this time, the shape of the assembly ring should be able to simultaneously press the end faces of the inner and outer circles of the bearing.

Separable cylindrical roller bearings, tapered roller bearings, thrust ball bearings, etc. can install the inner (shaft) ring and outer (seat) ring on the shaft and housing respectively. Be especially careful when placing the shaft with the inner ring installed into the bearing housing with the outer ring installed, and ensure alignment.

(2) Heating and cooling methods

When the bearing size is large or the interference is large, the required installation force will increase significantly. Therefore, the principle of thermal expansion and contraction can be used for installation. Generally, oil bath heating (be careful not to place the bearing directly on the bottom of the heating container, and use brackets or other objects to support the bearing to ensure uniform heating) or induction heater heating are used. The more suitable heating temperature range is 80℃-100℃, and the maximum temperature cannot exceed 120℃. After the installed bearing cools, the width direction will shrink, so it should be fixed with nuts or other appropriate methods to prevent gaps between the ring end face and the shaft shoulder.

2. Disassembly of rolling bearings

If the bearing is to be used again after being disassembled, it is not allowed to transmit the disassembly force through the rolling element, otherwise the rolling element and the raceway will be crushed. For non-separable bearings, first remove the auxiliary bearing from the looser fitting surface, and then use a press to press the bearing out from the tight fitting surface. You can also use a special disassembler to disassemble the bearing. For example: a double-tie rod disassembler as shown in Figure 3 and a three-tie rod disassembler as shown in Figure 4.