Abstract: Vertical-spindle surface grinding is capable of multiple processing tasks such as ultra-precision grinding and heavy-load grinding. However, excessive contact surface between the wheel and workpiece can impair the effect of cooling and lubrication provided by the grinding fluid, consequently leading to a high grinding temperature. A thorough understanding of the grinding heat transfer mechanism is pivotal for analyzing temperature fields and controlling thermal damage. Utilizing measured grinding temperature signals and a curved-surface contact moving heat source model, an inverse heat transfer methodology is developed to determine the heat flux distribution in vertical-spindle surface grinding. Subsequently, a model is constructed that incorporates the wheel-workpiece contact geometry into the heat flux distribution analysis. The impact of material removal and the cooling lubrication by the grinding fluid on grinding heat transfer mechanism is examined, using the energy partition ratio, effective thermal conductivity of the wheel/fluid composites, and convection heat transfer coefficient as benchmarks. Increased grinding depth extends the primary grinding zone, causing more abrasive layers to engage in cutting, and making it difficult for the grinding fluid to penetrate this zone. As a result, there is an elongation of the heat flux signal, an increase in the amplitude, and a shift in the peak position outward.Enhancements in grinding speed and feed rate keep the wheel-workpiece contact geometry and local grinding depth consistent, but modify the undeformed chip thickness. This modification diminishes the cooling lubrication effect of the grinding fluid within the grinding zone and its convection cooling effect outside, affecting the heat flux distribution only in terms of amplitude, not shape.

Key words: vertical-spindle surface grinding, wheel-workpiece contact geometry, heat flux distribution, energy partition ratio, convection heat transfer coefficient