What is the selection principle of grease for plain bearings?
1. Working environment analysis of sliding bearings in use(1) bearing load, high speed, should choose cone penetration of grease, and vice versa, we should choose cone penetration. If the high-speed bearings, cone penetration is small, good mechanical stability of grease. Special attention is paid to the lower viscosity of the base oil of the grease(2) the drip point of grease should be used at 20-30 degrees higher than the working temperature. In the case of continuous running at high temperature, special attention should be paid not to exceed the allowable temperature range of grease(3) if the sliding bearing works in water or wet environment, choose the calcium base, aluminum base or lithium base grease with good water resistance(4) the grease with better adhesion is chosen
3 、 lubrication cycle of sliding bearing grease:Continuous operation, the working temperature is 40-100 degrees, the shaft speed is less than 200r/min, the lubrication cycle is once every shift, the shaft speed is > 200r/min, and the lubrication cycle is two times per shift.Continuous operation, the working temperature is less than 40 DEG C: the shaft speed is less than 200r/min, the lubrication cycle is 1 days, the shaft speed is >200r/min, and the lubrication cycle is one time per shift.Interrupted work: the shaft speed is less than 200r/min, the lubrication cycle is 2 days, the shaft speed is > 200r/min, and the lubrication cycle is 1 days.Occasional work, not important parts: shaft speed < 200r/min, lubrication cycle 5 days once; shaft speed > 200r/min, lubrication cycle once every 3 days.
2. Selection of grease for sliding bearingsLoad 1-6.5MPa, shaft neck circumference speed below 1m/s, the maximum working temperature of 50-100 DEG C, the No. 2 lithium greaseLoad > 5MPa, journal circumferential speed 0.5m/s, maximum operating temperature 60 DEG C, roll No. 2 calender greaseThe load is less than 1MPa, the circumferential speed of the journal is below 1m/s, the maximum working temperature is 75 DEG C, and the No. 3 calcium base grease is usedLoad 1 - 6.5MPa, journal circumferential speed 0.5-5m/s, maximum operating temperature 55 DEG C, and use No. 2 calcium base greaseLoad > 6.5MPa, journal circumferential speed 0.5m/s below, maximum working temperature 75 DEG C, choose No. 3 calcium base greaseThe load is less than 6.5MPa, the shaft neck circumference speed 0.5-5m/s, maximum working temperature of 120 DEG C, the No. 2 lithium greaseLoad > 6.5MPa, journal circumferential speed 0.5m/s below, maximum working temperature 110 degrees, choose 2 calcium sodium base greaseCalcium base grease should be considered when the temperature is 75-120 degrees centigrade in humid environment;The working temperature should be below 75. The calcium base grease No. 3 should be considered. If not, the aluminum base grease can be used instead;The temperature at 110-120 DEG C, available barium grease or grease, lubrication, consistency to be smaller.
