Introduction Of Sliding Bearing Assembly
Sliding bearing is a kind of sliding friction bearing, which is characterized by smooth operation, reliable noise, and can withstand heavy loads and large impact loads. It can be divided into integral type, split type and pad type according to the structure.
(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, and hot-packing is used for special occasions. Most bushings are made of copper or cast iron and assembled Care should be taken when assembling with wooden hammers or hammer pads. When the tolerance of the interference dimension is large, press it in. Whether it is knocked or pressed, it must be prevented from tilting. After assembly, the oil groove and oil hole should be in the required position.
Bearings that are deformed after assembly should be trimmed with inner holes. Reamers can be used for smaller sizes, and scrapers for larger sizes. At the same time, pay attention to control the clearance between the shaft and the shaft within the tolerance range. In order to prevent the shaft sleeve from rotating during operation, the contact surface of the shaft sleeve and the box body is equipped with a positioning pin or a riding screw. Due to the different hardness of the casing and the sleeve material, it is easy to deflect the drill bit to the soft material side. The solution: one is to punch the hard material with a sample before drilling, and the second is to use a short drill to increase the drill. The rigidity of the drill when making holes.
2) Assembly of split bearings
Split bearings, also known as split bearings, have the characteristics of simple structure and easy adjustment and disassembly. Two bearing pads are inserted on the bearing pads, and a reasonable gap is adjusted with gaskets at the joints.
① Assembly of bearing shell and bearing body
The contact between the upper and lower bearing pads and the hole in the bearing body must be good. If it does not meet the requirements, use the hole in the bearing body of the thick-walled bearing as the reference, scrape the back of the bearing pad, and the steps at both ends of the bearing pad should be close to the two ends of the bearing body. The thin-walled tile only needs to make the mid-segment surface of the bearing pad higher than the mid-segment surface of the bearing body by about 0.1 mm, and does not need to be scraped.
② The bearing bush is installed in the bearing body
No displacement is allowed in either the radial direction or the axial direction. Steps at both ends of the bearing pad are usually used to stop positioning or positioning pins.
③ Shaft matching
The split bearing usually uses the matching shaft grinding point. Generally, the bearing is scraped first, and then the bearing is scraped. In order to improve efficiency, the bearing pad and cover are not installed when the bearing is scraped. The contact point of the lower bearing is basically When it meets the requirements, the upper bearing bush and the upper cover are pressed tightly, and when the upper bearing pad is scraped, the contact point of the lower bearing pad is further corrected. The degree of tightness of the shaft during scraping can be adjusted by changing the thickness of the gasket as the number of scraping increases. After the bearing cover is tightened, the shaft can easily rotate without obvious gaps, and the contact point meets the requirements and the scraping is completed.
④ Measurement of bearing clearance
The size of the bearing gap can be adjusted by the spacer at the mid-parting surface, or it can be obtained by directly scraping the bush. The bearing clearance is usually measured by the lead pressing method. Take a few pieces of lead wire with a diameter larger than the bearing clearance and place it on the journal and the mid-partial surface. Then tighten the nut to make the mid-partial surface tight. Take out the flattened lead wire and measure the thickness with a micrometer for each section. Based on the average thickness of the lead wire, you can know the bearing clearance.
Generally, the clearance of the bearing should be 1.5 ‰ -2.5 ‰ (mm) of the shaft diameter. When the diameter is larger, the smaller clearance value is adopted. If the shaft diameter is 60mm, the bearing clearance should be between 0.09-0.15mm.