What are the advantages and disadvantages of plain bearings compared with those of rolling bearings?
(1) types and characteristics of plain bearings1. the sliding bearings are divided according to the load:(1) radial sliding bearing (radial sliding bearing), mainly bearing radial load;(2) thrust bearings are mainly subjected to axial load.2. sliding bearings are suitable for low speed, high precision, heavy load and structural requirements. It is also used at low speed and impact.3. center journal bearing(1) integral type and split fractionThe splitting is usually made up of bearing cap, bearing seat, bearing bush and connecting bolt.(2) the Bush is the key part in the bearing.Bearing materials should have small coefficient of friction, good thermal conductivity, small coefficient of thermal expansion, wear resistance, corrosion resistance, strong adhesive resistance, sufficient mechanical strength and plasticity.(3) requirements for bearing materials: bearing alloy (Babbitt), bronze, bearing materials of special properties, etc..4. thrust plain bearings (understood)(1) the thrust bearing fixed and tilting.(2) the thrust surface of thrust bearing can use the end surface of the shaft, or can make a convex shoulder or thrust the disc in the middle of the shaft.(two) types and characteristics of rolling bearings1. classification of rolling bearingsAccording to the shape of the rolling body is divided into: ball bearings, roller bearings.2. characteristics of rolling bearings(1) advantages:Compared with plain bearings, rolling bearings have the advantages of small frictional resistance, quick starting, high efficiency, simple lubrication and easy replacement.(2) shortcomings:Low impact resistance, noise at high speed, and less working life than liquid lubricated sliding bearings.
Disadvantages of plain bearings:1) the friction coefficient is large, and the power consumption is too much.2) not suitable for mass production, interchangeability is not good, it is not easy to install, disassemble and repair.3) the internal clearance is big, the processing precision is not high.4) low transmission efficiency, large heat consumption, inconvenient lubrication and maintenance, consumption of lubricant.5) the load, the speed and the working temperature have a narrow range of adaptation, and a small change in the working conditions will greatly affect the performance of the bearings.6) can not bear radial and axial load simultaneously.Plain bearings: bearings that work under sliding friction. Plain bearings are stable, reliable and noiseless. They are used under low speed, light load or intermittent working conditions.
Compared with rolling bearings, sliding bearings have advantages:1) the sliding bearing is compact, and the bearing capacity of the plain bearing is much larger at the same size.2) plain bearings allow for high accuracy, low vibration and noise.3) the sliding shaft bears little influence on metal foreign body, and it is not easy to produce early damage.
