Coolant flow in surface grinding with non-porous wheels

A parameter that is often used in the assessment of cooling efficiency in g rinding is the amount of fluid that flows through the grinding zone. This p aper shows that when grinding with wheels possessing no bulk porosity, only a portion of the now through the grinding zone is effective. Even at the h ighest wheel speeds employed, it is observed that ample fluid travels on th e wheel surface and is re-directed into the grinding zone - a phenomenon th at may adversely affect cooling and wheel cleaning. Therefore fluid rejecti on off the wheel is important. A theoretical model for fluid rejection is p roposed, that describes the drop formation process, presents the operating instabilities, identifies characteristic time and length scales, and predic ts the amount of rejected fluid. Although the surface roughness of the whee l is important in quantifying coolant Row rates, a smooth wheel is employed in this work to study first order effects. Preliminary experimental result s obtained for a rough grinding wheel are in conformance with those for a s mooth wheel. (C) 2000 Elsevier Science Ltd. All rights reserved.