Sliding bearing assembly
The sliding bearing is a kind of sliding friction bearing. It is characterized by stable operation, low reliability, low load, heavy load and large impact load. It can be divided into integral type, split type and tile type according to different structural forms.
(1) Assembly of integral sliding bearing
Integral sliding bearings, commonly known as bushings, are also the simplest form of sliding bearings. They are mainly assembled by press-in and hammering. Hot-filling is used for special occasions. Most bushings are made of copper or cast iron. Care should be taken when assembling with a wooden hammer or hammer pad. If the interference tolerance is large, press it with a press. The tilting must be prevented regardless of the knock-in or press-in. After assembly, the oil sump and oil hole should be in the required position.
For bearings that are deformed after assembly, the inner hole should be trimmed, the smaller size can be used for reamer cutting, and the larger size can be scraped. At the same time, pay attention to the matching clearance between the control and the shaft within the tolerance range. In order to prevent the rotation of the sleeve during operation, the contact surface of the sleeve and the box body is provided with a positioning pin or a riding screw. Since the hardness of the material of the box body and the sleeve material is not the same, it is easy to make the drill bit biased to the side of the soft material. The solution is as follows: one is to punch the hard material while drilling, and the other is to use a short drill bit to increase the drill. The rigidity of the bit when the hole is drilled.
(2) Assembly of split bearings
Split bearing, also known as split bearing, has the characteristics of simple structure, convenient adjustment and disassembly, two bushings on the bearing bush, and a reasonable gap between the joints.
1 .Assembly of bearing bush and bearing body
The contact between the upper and lower bearing pads and the hole in the bearing body must be good. If the bearing body hole of the thick-wall bearing bush is not met as required, the back of the bearing bush should be scraped, and the ends of the bearing bush should be close to the two ends of the bearing body. The thin-walled tile can be used as long as the mid-section of the bearing bush is about 0.1 mm higher than the mid-section of the bearing body.
2 .The bearing bush is installed in the bearing body, no displacement is allowed in radial or axial direction. Generally, the steps at both ends of the bearing pad are used to stop positioning or positioning pin positioning.
3 .bearing bushing
For the split bearing bush, the shaft is usually used to match the shaft. Generally, the bearing bush is scraped off first, and then the bearing bush is scraped. In order to improve the efficiency, the bearing bush and the cover are not installed when the bearing bush is scraped, and the contact point of the lower bearing bush is basically When the requirements are met, the upper bearing bush and the upper cover are pressed together, and the contact point of the lower bearing bush is further corrected when the upper bearing bush is scraped. The degree of tightness of the shaft when shaving can be adjusted by changing the thickness of the gasket as the number of scraping increases. When the bearing cap is tightened, the shaft can be easily rotated without significant clearance, and the contact point meets the requirements, that is, the scraping is completed.
4 .Measurement of bearing clearance
The size of the bearing clearance can be adjusted by the spacer at the mid-section, or by directly shaving the bearing. To measure the bearing clearance, the lead-lead method is usually adopted. Take a few lead wires with a diameter larger than the bearing clearance, place it on the journal and the middle split surface, then tighten the nut to press the middle split surface, then unscrew the nut, remove the bearing cap, and carefully The flattened lead wire is taken out, and the thickness is measured for each micrometer. The bearing gap can be known according to the average thickness of the lead wire. Generally, the clearance of the bearing should be 1.5‰-2.5‰(mm) of the shaft diameter, and the smaller gap value should be taken when the diameter is larger. If the shaft diameter is 60mm, the bearing clearance should be between 0.09-0.15mm.
Reprinted from the network