Theoretical Investigation of Design Guidelines for Scraped Textures for Guideways Using the Taper-Land-Taper Bearing Model

Scraped textures have been applied to the slide guideways of machine tools to create fluid film lubrication.Recently, it was revealed that using lubricating oil with an acid phosphate ester additive can change solid friction in the mixed and boundary lubrication regimes to fluid friction.In a previous study, the friction coefficient and bearing gap of the guideways were evaluated using a taper-land-taper bearing (TLTB) model and a modified Reynolds equation that accounted for the effects of the high-viscosity surface layer caused by the additive oil.Using this verified theory, the present study clarifies the general bearing characteristics of TLTB-textured guideway in the high-and low-velocity regions for taper angle ranging from 0.001 to 0.006 rad.In the high-velocity region ranging from 0.125 to 2 m/s, the load capacity can be close to the maximum load-capacity condition when the taper angle is between 0.003 and 0.006 rad.The effects of the taper angle, bearing length, and load pressure on the bearing gap and stiffness were discussed.In the low-velocity region, a design method is proposed for starting and stopping within the velocity region where friction coefficient is proportional to velocity, expecting to suppress the stick-slip vibration.