(1) The guide rail is operated as close as possible to the liquid friction state to reduce the frictional resistance, reduce the driving power, and improve the efficiency.
(2) Reduce the wear of the guide rail and prevent the guide rail from corroding. The flowing lubricating oil also acts as a flushing agent.
(3) Avoid creeping under low speed and heavy load, and reduce vibration.
(4) Reduce frictional heat at high speed and reduce thermal deformation.