粉-气混合流润滑试验装置及摩擦学特性

为了研究粉气混合流在摩擦副间的润滑状况,采用空气压缩机及油水分离器提供高压干燥空气,并结合粉末流化和喷粉设备构建了向环块摩擦副间输送粉气混合流的粉末润滑试验装置。基于Timken摩擦磨损试验机,用石墨粉末进行一系列润滑试验。结果表明:此供粉装置能提供稳定持续的粉气混合流;石墨粉气混合流能进入到环块摩擦副中,使其保持良好的线接触并起到良好的润滑作用,摩擦系数在载荷达到450N时还不足0.1,并且随着载荷增大有减小趋势;摩擦力随着载荷的提高而增大,但总体上相对较小;磨损量也比较小,试件块的磨痕呈细细的条状;石墨粉气流通过环块摩擦副时将环块表面间的摩擦转换为石墨颗粒间的摩擦,并通过空气流将大部分热量带走,从而有效降低摩擦副的温度。

Establishment of experimental system and investigation of tribological properties of powder-gas flow lubrication

The purpose of this paper was to study the properties of powder-gas flow lubrication.An air compressor and oil-water separator were used to provide the high pressure dry air for the experimental equipment which was employed to transport powder-gas mixed flow to the tribo-pairs of a ring-block through a powder fluidization equipment.A series of lubrication experiments with the graphite powder as lubricant was performed based on Timken friction and wear tester.The results show that the device could provide stable and sustainable powder-gas mixed flow.The graphite powder-gas mixed flow injected into the tribo-pairs of a ring-block can make it keep good line contact and have a good lubrication function.Friction coefficient is below 0.1 while load is up to 450 N,and decreases with increasing of load.Fricition force increases with the increse of load,but is relatively small.The wear is also relatively small,and wear track of the block presents fine strips.When passing the tribo-pairs of a ring-block,the graphite powder-gas mixed flow convert the friction between surfaces of ring and block into the friction between graphite particles,and most heat is taken away by means of the air current,thus the temperature of tribo-pairs is decreased effectively.