Selection and characteristics of oil-free self-lubricating b

Selection and characteristics of oil-free self-lubricating bearings in casting:

 

Selection of oil-free self-lubricating bearings

 

In order to solve the problems of high temperature, low speed, heavy load, heavy dust, water spray and shock vibration in mechanical equipment, oil-free self-lubricating bearings are used.

 

1. Bearing structure Self-lubricating bearings are developed by arranging holes of appropriate size on the metal friction surface of the bearing base. The bearings are embedded with linear bearings such as molybdenum disulfide and graphite to make composite self-lubricating blocks embedded in metal sleeves. , The composite bearing made, the friction area of ​​solid lubricant reaches 25-65%. Automotive Bearing Model Inquiry Software Bearing World

 

The solid self-lubricating block can work normally at a high temperature of 280 ° C. However, due to its low mechanical strength, its ability to carry copper bushes is weak, and it is prone to deformation. It can be suppressed by inlaying it in metal holes, forming a metal part to carry the load and a self-lubricating block to lubricate. Automotive Bearing Model Inquiry Software Bearing World

 

The lubrication mechanism of this self-lubricating bearing is that during the sliding friction between the shaft and the sleeve, a part of the molecules of the self-lubricating material is transferred to the metal surface of the shaft, filling out the small uneven surfaces, and forming a relatively stable solid lubricant film. , Causing abrasion between the solid lubricating film, preventing adhesion and wear of the shaft and the sleeve. Automotive Bearing Model Inquiry Software Bearing World

 

This reasonable combination combines the complementary advantages of copper alloys and non-metal antifriction materials, and is especially suitable for motionless environments in oil-free, high temperature, high load, low speed, antifouling, corrosion, and strong radiation environments, and It can be used under special working conditions that are wet with water or other solutions and cannot be lubricated at all. Automotive Bearing Model Inquiry Software Bearing World

 

2. The ratio of self-lubricating block area to self-lubricating block is related to the operating speed and bearing strength, and the operating speed is low; the bearing strength is large, and the area occupied by metal should be larger. Automotive Bearing Model Inquiry Software Bearing World

 

For example, the area occupied by the self-lubricating block of the traveling wheel bearing of the ingot-carriage trolley is about 25%, and the shaft bearing of the pulling mechanism should be sufficiently lubricated, and the bearing strength is not large. The area of ​​the self-lubricating block is about 65%. Automotive Bearing Model Inquiry Software Bearing World

 

3. Technical requirements for the bushing material The bushing should be made of alloy copper. The bushing must have a high hardness, and generally requires heat treatment. Its hardness is not lower than HRC45. Bearing business navigation

 

4. Geometry and mosaic requirements of self-lubricating block. There are two types of self-lubricating blocks: cylindrical and rectangular. Self-lubricating blocks can be cylindrical according to the area they occupy, otherwise they can be rectangular. Whatever the shape, it must be set firmly to prevent it from falling off during operation. Bearing business navigation

 

5. The value of the clearance between the bush and the shaft is about 10 times the coefficient of linear expansion of the self-lubricating block. Bearing business navigation

 

In order to adapt to changes in bearing temperature, the gap between the shaft and the bushing was adjusted from 0.032 to 0.15MM by the original four-stage dynamic fit of the metal parts (D4 / DC4), increasing to 0.45 to 0.5MM. Bearing business navigation

 

The self-lubricating block protrudes the bush metal 0.2-0.4MM on the side of the friction pair. In this way, the bearing will be fully lubricated during the initial running-in period of the bearing, reducing the power consumption of the power drag. Bearing business navigation

 

6, the advantages of oil-free self-lubricating bearings

 

A. Oil-free or low-oil lubrication, suitable for places where refueling is difficult or difficult, and can be used without maintenance or less maintenance; automobile bearing model query system

 

B. Good abrasion resistance, small friction coefficient and long service life; automobile bearing model query system

 

C. There is a proper amount of elastoplasticity, which can distribute the stress over a wide contact surface, and improve the bearing capacity of the bearing; the automobile bearing model query system

 

D. The static and dynamic friction coefficients are similar, which can eliminate crawling at low speeds, thereby ensuring the working accuracy of the machinery; automobile bearing model query system

 

E. It can make the machine reduce vibration, reduce noise, prevent pollution and improve working conditions; automobile bearing model query system

 

F. During the operation, a transfer film can be formed to protect the shaft from grinding. There is no shaft biting phenomenon; automobile bearing model query system

 

G. The hardness requirements for grinding shafts are low, and unadjusted shafts can be used, which reduces the processing difficulty of related parts; automotive bearing model query system

 

H. Thin-walled structure, light weight, can reduce mechanical volume; automobile bearing model query system

 

I. The bush is made of brass and can be used in corrosive media. Car bearing model query system

 

 

 

Author: Zhangjiagang City Shuanglong Wangting Oil Sliding Bearing Co., Ltd.

 

Website: http://www.zsl-bearings.com