Bearing grease shortcomings - bearing when using knowledge

Used in bearing grease has many advantages, but there are also several disadvantages: ( 1) Grease is semi-solid, room temperature does not flow, so the friction parts in fatliquoring or grease is difficult to change, bearing cleaning is not very convenient. ( 2) Mixed with water, dust, abrasive dust is difficult to separate. If the lubricating oil, general heavy impurity in the lower part, or through the filter is easy to get rid of. ( 3) Stir the resistance is bigger, therefore calorific value larger, cooling effect is poor. But should pay attention to some here, which have close relationship with lubrication method. Such as lubricating oil by complete immersion ( Or half immersed) Type of lubricating oil bath, with the power of small fat rather than oil consumption. Such as the British journal of friction and lubrication in 1973 6: with a diameter of 100 rolling bearing, the speed of 1500 r/min, with grease lubrication, such instances are also a lot of domestic energy consumption, such as refractory plant of chongqing iron and steel company of refractory tunnel kiln of induced draft fan motor for power than using N68 lubricating oil, grease bearing temperature lowered 4 ~ 6 ° C. ( 4) For high speed is not applicable. Generally speaking, the ordinary mineral oil grease only allows you to use to convey speed be DN value ( The inner diameter of the bearing mm x speed r/min) Less than 300000 mm r/min. With the development of grease technology, synthetic lubricant can be used to DN value from 500000 to 600000, or 1 million. The most high-speed instance is (to use grease In 1984 Japan 'defense technology') High altitude unmanned reconnaissance jet aircraft of the bearing, in order to reduce the weight of the plane, with grease lubrication. Bearing inside diameter ф 25 mm, the temperature is 200 ° C, the speed of 4600 r/min, DN value is 1. 8 million, with flattering synthetic grease meet the operating requirements (30 min life 5) Stir the resistance is bigger, therefore calorific value larger, cooling effect is poor.