Optimization by Crowning Piston and Protection of Sleeve by application of Heat Resistant insulation in super finishing Lathe Attachment

Abstract

The problem in super finishing lathe attachment solved by applying a coat of Ebonite (Hard Rubber) from inside of the sleeve. This avoids the expansion of the sleeve above 5 microns and restricts it to 2 microns only, which is necessary for the smooth, uninterrupted and continuous operation of super-finishing lathe attachment. Now the challenge faced during the assembly of the sleeve into the Cylinder is that the assembly is a transition fit and the cylinder is heated (for expansion purpose) and the sleeve is inserted into it, this heat is transferred to Ebonite coating, which spoils the Ebonite coating and hence cannot maintain a gap of 5 micron between the Sleeve and the piston. A hightemperature insulated coat of 64C1-2-A is applied from outside of the sleeve, this acts as a barrier between the heatedcylinder and the ebonite coating. Further the friction in these two the OHNS piston and the ebonite coated sleeve is reduced by the process of crowning the piston. Crowning reduces the surface contact, resulting in further smooth and continuous operation while used in Super-finishing lathe attachment.