Bearing is an important part of contemporary mining machinery, and its quality is related to the operation of the whole equipment. The following describes the installation, Service Life maintenance, disassembly and common problems of bearings.
The bearing installation directly affects the accuracy, service life and performance. Therefore, the design Service Life and assembly department shall fully study the bearing installation according to the following operation standards:
(1) Clean the bearing and bearing related parts;
(2) Check the size and finish machining of related parts;
(3) Installation (just before installation, open the bearing package);
(4) Inspection after bearing installation;
(5) Supply lubricant.
General grease lubrication, do not clean, directly fill with grease. For lubrication with lubricating oil, it is not necessary to clean in general. Service Life However, bearings for instrument or high-speed use shall be cleaned with clean oil to remove the antirust agent coated on the bearings.
The bearing with rust inhibitor removed is easy to rust, so it can not be placed regardless. Moreover, Service Life bearings sealed with grease can be used directly without cleaning.
The installation method of bearing varies according to the bearing Service Life structure, fit and other conditions. Generally speaking, because most of them are shaft rotation, the inner ring needs an interference fit.
Cylindrical bore bearings are usually pressed in with a press or hot Service Life installed. In the case of taper hole, it can be directly installed on the taper shaft or installed with sleeve.
01. Installation of cylindrical hole bearing
(1) Press in method with press
Press in method is widely used for Service Life small bearings. Put the cushion block into the inner ring and press it quietly with a press until the inner ring contacts the shaft shoulder closely. The outer ring is padded with a cushion block and installed on the inner ring, which is the cause of indentation and bruise on the raceway, so it is absolutely prohibited.
During operation, oil the mating surface in advance. When it is Service Life absolutely necessary to knock the installation with a hammer, cushion blocks shall be placed on the inner ring for operation. This method is limited to the case of small interference, and can not be used for large interference, medium and large bearings.
For non separable bearings such as deep groove ball bearings, when the inner ring and outer ring need interference installation, pad them with cushion blocks, and press the inner ring and outer ring together with screw or oil pressure.
The outer ring of self-aligning ball bearing is easy to tilt. Even if it is not an interference fit, it is also padded with cushion blocks for installation.
For separate bearings such as cylindrical roller bearings and tapered roller bearings, the inner ring and outer ring can be installed on the shaft and housing respectively. When combining the installed inner ring and outer ring, the key is to stably close them so that their centers do not deviate, and pressing them will cause jamming on the raceway surface.
Large bearings require a lot of force when pressing in, so it is difficult to press in. Therefore, the hot installation method of heating the bearing in oil to expand it and then installing it on the shaft is widely used. Using this method, the operation can be completed in a short time without adding improper force to the bearing.
The heating temperature of the bearing is based on the bearing size and the required interference. Precautions for hot assembly are as follows:
(a) Do not heat the bearing above 120 ℃;
(b) In order to prevent the bearing from directly contacting the bottom of the oil groove, it can be considered to place the bearing on the metal mesh platform or lift the bearing;
(c) Heat the bearing to 20 ℃ – 30 ℃ higher than the required temperature so that the inner ring will not become cold during operation and it is difficult to install;
(d) After installation, the bearing cools down and shrinks in the width direction, so it should be fastened with shaft nut or other appropriate methods to prevent gap between inner ring and bearing shoulder.