Generally use grease, oil rope form and drip lubrication, shaft and bearing surface are not enough lubricant, the liquid film is not continuous. Simple structure, large friction coefficient, wear large.
a. Integral
The gap between the shaft and the bearing can not be adjusted, simple structure, can only be attached and detached from the shaft journal. Generally used for low-speed, light-load and disassembly allow machines.
b. Split
The gap between the shaft and the bearing can be adjusted, easy to install. When the machine disassembly difficult, often used in this way.
c. the pad may be appropriate to swing in the housing in order to accommodate shaft deflection produced when bent. There shaft deflection for the occasion, in which there is mutual joint bearings for oscillating rod junction radial load.
(2) a thrust sliding bearing
Common plane thrust bearing, due to the lack of liquid friction conditions, and in an incomplete state of fluid lubrication, to be used simultaneously with the radial bearings. For axial force occasion.
(3) bearing powder metallurgy (oil bearing)
Porous, oil stored in the pores, in a long time, but can not add oil automatic lubrication, guaranteed to work, but because of its relatively soft material, it is subjected to a lower load capacity. For light load, low speed and easy refueling situation.
(4) plastic bearings
Compared with metal bearings, plastic bearings and light weight, easy to maintain. Chemical stability, wear resistance and fatigue strength, and has a vibration, acoustic, self-lubricating, insulating and self-extinguishing. But the thermal expansion coefficient, low thermal conductivity, moisture absorption greater strength and dimensional stability better than metal. For speed is not high or good place heat dissipation, operating temperature should not exceed 65 ℃, instantaneous temperature does not exceed 80 ℃.
(5) Rubber Bearings
Can absorb vibration and impact, in an environment impurities wear and corrosion resistance, but the unit lower strength than metal poor heat resistance, not suitable for use at high temperatures and organic solvents and oils or contact environment. For ships bearing shaft tube shall vibration and corrosive environments.
(6) Wood bearing
Cheap wooden bearing light, can absorb impact, small deflection sensitivity of the shaft, but low strength, thermal resistance and moisture resistance, abrasion resistance is poor. For light load conditions to be vibration, such as agricultural machinery disc harrow bearings, large grain ore pump bearings.
2. The fluid-lubricated bearings
(1) hydrodynamic bearing
Between the journal and the bearing surface of the film completely separated. Hydrodynamic bearings must have: ① bearing sufficient speed; ② have sufficient amount of oil, lubricating oil has a certain viscosity; ③ between the journal and the bearing surface with the appropriate clearance. More oil wedge hydrodynamic bearing axis to meet the requirements of high-precision rotation, long life. For high-speed and high-precision machinery, such as centrifugal compressor bearings.
(2) The hydrostatic bearing
Journal and bearing oil film bearings are supplied outside certain pressure completely separated, limited slip speed of the oil film is not a relative, have a greater carrying capacity in a variety of speeds (including zero speed) down. Stability shaft to meet the requirements of high precision rotary axes, the friction coefficient is small, high mechanical efficiency, long life.
(3) Gas dynamic pressure, static pressure bearing
Gas dynamic pressure, static pressure bearing, as lubricant with air or other gases, friction coefficient, high mechanical efficiency, to meet the requirements of the operation told. Gas bearings are used as the gyro, TV recorder bearings.
3. The non-lubricated bearings (plastic, carbon graphite bearing)
Operate without lubricating oil or grease state. Seldom used.
4. Other
(1) solid lubricating bearings
Graphite, molybdenum disulfide, phthalocyanine dyes, PTFE and other solid lubricants lubrication. For extremely low temperature, high temperature, high pressure, strong radiation, space, vacuum and other special working conditions.
. (2) a magnetic bearing with a magnetic fluid flow as a lubricant;
. b static electricity force field bearing shaft suspension;
c. magnetic bearings using a magnetic field so that the shaft suspension.
Used for high-speed machinery and instrument.