応力波による案内面摩擦の制御 : 鋼球打撃による摩擦係数の低減

概要

論文の詳細を見る
In general, when a slider is about to be moved, friction is always at the maximum. This phenomenon has made it difficult to locate a slider at a definite position with submicron accuracy. The authors attempted to challenge this widely accepted concept in this paper. The basic idea is to strike a guideway from the side with a small steel ball, so that stress waves are generated in the body of the guideway. The stress waves induce slight movement of the asperities on the surface of the guideway. The movement will lead to the breakage of metal-to-metal cohesion and will cause considerable decrease in friction. The idea was tested using a steel block with a hardened surface for a guideway and another smaller block for a slider. The results obtained are as follows. (1)Even a small ball can induce a considerable change in the relative slding speed of metal-to-metal contact regions between the guideway and the slider. The relative movement is strongly dependent on the kinetic energy of the ball. (2) The above movement causes a great reduction in the friction coefficient. When a ball of 25.4mm diameter is dropped from a height of 80mm, the coefficient of friction drops from 0.37 to 0.05 when the slider speed is 1 × 10^<-2>mm/sec. (3) Though the low friction level is sustained for only 0.02sec, this period is long enough for a slider to start moving. (4) The lower the slider speed, the greater the reduction in friction.
1993-11-25