The choice of oil-free self-lubricating bearings
In order to solve the mechanical equipment in high temperature, low speed, large overload, dust, water shower and have impact vibration lubrication problem, choose oil-free self-lubricating bearings.
1. The structure of the bearing self-lubricating bearing is developed on the surface of the bearing substrate metal friction pores, orderly arrangement of the appropriate size and embedded mos2 and graphite etc made from composite self-lubricating block set on the metal sleeve, made of composite bearing, friction area of 25-65% of solid lubricants.Solid self-lubricating block can work normally under the high temperature of 280 ℃.But due to its low mechanical strength, bearing capacity is weak, easy to deformation, it is embedded in the metal hole groove can inhibit the shortcomings, to form the metal parts load-bearing role, self-lubricating block lubrication.The self-lubricating bearing lubrication mechanism is in the process of shaft and the set of sliding friction, part of the self-lubricating materials transferred to the axis of the metal surface, fill tiny is not flat, and formed a relatively stable layer of solid lubricating film, solid lubrication film between the grinding, prevent shaft and set of adhesive wear.The rationality of the combination of a combination of copper alloy and non-metallic antifriction materials of their complementary advantages, particularly suited to oil-free, high temperature, high load, low speed, anti-fouling, corrosion resistant, strong radiation in the environment movement, and in the water or other solution infiltration and cannot add grease used under special working conditions.
2. The self-lubricating block size than the self-lubricating block accounts for much of the surface of related to the intensity of the running speed, pressure, speed is low;Pressure strength, metal thrown some of area.Such as catch ingot tractor road wheel bearing self-lubricating block covers an area of about 25%, of the pull mechanism shaft bearing lubrication to fully, bearing strength is not big, self-lubricating block area of about 65%.
3. The transform of materials technical requirements of the bushing should choose copper alloy manufacture, bushing should have high hardness, generally must be heat treatment, the hardness is not lower than HRC45.
4. Self-lubricating block geometry and set requirements.Self-lubricating block shape is cylindrical and rectangular, self-lubrication can be used according to the size of bar, vice can use rectangle.No matter what the shape must be set firmly to prevent fall off in the running.
5. Fitting clearance of bushing and axis value of self-lubricating block linear expansion coefficient is about 10 times that of the steel.In order to adapt to the bearing temperature changes, the clearance between the shaft and bushing from metal pieces of four grades (D4 / dc4) 0.032 ~ 0.15 mm, 0.45 ~ 0.5 mm.Self-lubricating block at the side of the friction pair is prominent bushing metal 0.2 ~ 0.4 mm.This will get sufficient lubrication in bearing the initial period of operation, reduce power drag power consumption.
6. The advantages of the oilless self-lubrication bearing:
A. oil lubrication oil free or less, apply to cannot go or it’s hard to go places, but when use less maintenance and maintenance.
B. wear-resisting performance is good, small friction coefficient, long service life.
C. have just the right amount of elastic-plastic, can the stress distribution in wide contact surface, improve the bearing capacity.
D. the static friction coefficient, can eliminate the crawling under low speed, so as to ensure the accuracy of the mechanical work.
E. can reduce mechanical vibration, reduce noise, to prevent pollution, improve working conditions.
F. transfer film formation during the operation process, have the effect of protection of grinding axis, no bite shaft phenomenon.
G. for low grinding shaft hardness requirements, without the shaft can be used as, which reduces the processing difficulty of related parts.
H. thin-walled structure, light quality, can reduce the mechanical volume.
I. liner is made of brass, and can be used in the corrosive medium.
Through some aluminum enterprise practice, casting machine bearing, oil-free self-lubricating bearings, has used 15 months in a row, and also in the running, the clearance between the shaft and bushing is generally less than 1 mm, 12 months, is expected to also can be used to significantly more than the service life of the original (2 months).Oilless self-lubrication bearing not only can been used in aluminum ingot casting machine is better, and can be adapted to the oil-free, high temperature, high load, low speed, anti-fouling, corrosion resistant, strong radiation in the environment movement, and in the water or other solution infiltration and cannot add grease under special working conditions of equipment, this kind of bearing has wide popularization value.
Currently used various machinery industry is the most or the ball bearing, needle roller bearings and so on, but a small number of self-lubricating bearings has been adopted, believe in the near will from lubrication bearings bearing has become the dominant.
The application of the following is a part of self lubricating bearing characteristics and advantages:
1. The lubrication oil free or less, apply to cannot go or it’s hard to go places, but when use less maintenance and maintenance.
2. The wear-resisting performance is good, small friction coefficient, long service life.
3. Have the right amount of elastic-plastic, can the stress distribution in wide contact surface, improve the bearing capacity.
4. The static coefficient of friction, can eliminate the crawling under low speed, so as to ensure the accuracy of the mechanical work.
5. Can reduce mechanical vibration, reduce noise, to prevent pollution, improve working conditions.
6. Transfer film formation during the operation process, have the effect of protection of grinding axis, no bite shaft phenomenon.
7. Low hardness requirements for grinding axis, conditioning treatment without shaft can be used, which reduces the processing difficulty of related parts.
8. Thin-walled structure, light quality, can reduce the mechanical volume.
9. The steel back can be plating a variety of metal, can be used in the corrosive medium;At present has been widely used in various mechanical sliding parts, such as: printing machines, textile machines, tobacco machinery, micro-motor, automobiles, motorcycles and forestry machinery and so on.