Assembly of sliding bearing:

Sliding bearing is a kind of sliding friction bearing, which is characterized by stable operation, reliability, low noise, and can withstand heavy loads and large impact loads. It can be divided into integral type, split type and tile type.

(1) Assembly of integral sliding bearing

Integral sliding bearing, commonly known as bushing, is also the simplest form of sliding bearing, mainly by pressing and hammering. For special occasions, the hot-loading method is used. Most of the bushings are made of copper or cast iron. Care should be taken when assembling. They can be assembled by hitting with a wooden hammer or a hammer block. When the interference size tolerance is large, use Press in. Whether it is knocked in or pressed in, it must be prevented from tilting. After assembly, the oil groove and oil hole should be in the required position.

Deformed bearings after assembly should be trimmed in the inner hole, the smaller size can be cut with a reamer, and the larger size can be scraped. At the same time, pay attention to control the matching clearance with 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 seam screw. Due to the different hardness of the box body and the shaft sleeve, when drilling, it is easy to make the drill bit deviate from the soft material. The rigidity of the drill bit when the hole is made.

(2) Assembly of split bearing

Split bearing, also known as split bearing, has the characteristics of simple structure, convenient adjustment and disassembly , Put two bearing bushes on the bearing bush, and use a gasket at the joint to adjust a reasonable gap.

①Assembly of bearing pad and bearing body

The contact between the upper and lower bearing pads and the bore of the bearing body must be good. Using the internal hole as the benchmark, grind the back of the bearing pad, and at the same time, make the steps at both ends of the bearing pad close to both ends of the bearing body. Thin-walled bushes only need to make the mid-section of the bearing bush about 0.1mm higher than the mid-section of the bearing body, and it is not necessary to repair and scrape.

②The bearing bush is installed in the bearing body

No displacement is allowed in either radial or axial direction. Usually, the steps at both ends of the bearing bush are used to stop and locate Or positioning pin positioning.

③Scraping of the bearing bushes

The split bearing bushes generally use the matching shaft grinding point. Generally, the bearing bushes are scraped off first, and then Scrape up the bearing bush. In order to improve the efficiency, the bearing bush and cover may not be installed when scraping off the bearing bush. When the contact point of the lower bearing bush basically meets the requirements, then the upper bearing bush and the scallops are scraped and grinded. The upper bearing bush is further corrected. Bearing contact point. When scraping, the tightness of the shaft can be adjusted with the increase of scraping times by changing the thickness of the gasket. When the bearing cover is fastened, the shaft can be easily rotated without obvious clearance, and the contact point can be scraped as required.

④Measurement of bearing clearance

The size of bearing clearance can be adjusted by the shim at the mid-section, or obtained by directly scraping the bearing bush. The bearing clearance is usually measured by pressing the lead method. Take a few pieces of lead wire with a diameter larger than the bearing clearance and place them on the journal and the mid-section surface, then tighten the nut to press the mid-section surface tightly, then unscrew the nut and remove the bearing cover. Carefully Take out the flattened lead wire, and measure the thickness with a micrometer for each section taken. The bearing clearance 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 clearance value is taken when the diameter is larger. If the shaft diameter is 60mm, the bearing clearance should be between 0.09-0.15mm.

Assembly of rolling bearing:

Rolling bearing has the advantages of convenient replacement and simple maintenance.

(1) Technical requirements for assembly

①The end face marked with the code of the rolling bearing should be installed in the visible direction for easy replacement time check.

②The radius of the arc at the step of the journal or housing hole should be smaller than the radius of the arc at the corresponding place on the bearing.

③After the bearing is assembled on the shaft and in the housing hole, there should be no skew.

④In the two coaxial bearings, one must move with the thermal expansion of the shaft.

⑤When assembling rolling bearings, it is necessary to strictly prevent dirt from entering the bearing.

⑥The assembled bearing must operate flexibly, with low noise, and the working temperature should generally not exceed 65℃.

(2) Assembly method

When assembling the bearing, the most basic requirement is to make the added axial force act directly on the end face of the ring of the installed bearing (when installed on the shaft, the added axial force directly acts on the inner ring When installed on the hole, the applied force should act directly on the outer ring). Try not to affect the rolling elements. Assembly methods include hammering method, press assembly method, hot charging method, freezing assembly method, etc.

①Hammering method

Use a hammer to place a copper rod and some softer materials before hammering. Be careful not to use copper powder, etc. If foreign objects fall into the bearing raceway, do not directly hit the inner and outer rings of the bearing with a hammer or punch, so as not to affect the matching accuracy of the bearing or cause bearing damage.

②Assembly method of screw press or hydraulic press

For bearings with large interference tolerance, screw press or hydraulic assembly can be used. Before pressing, the shaft and bearing should be leveled and coated with a little lubricating oil. The pressing speed should not be too fast. After the bearing is in place, the pressure should be quickly removed to prevent damage to the bearing or shaft.