Small-dimensional sandwich grinding wheels with a centrifugal coolant provision system for traverse internal cylindrical grinding of steel 100Cr6

The following article characterizes the problems occurring in the traverse internal cylindrical grinding process. It has been concluded that an effective way of influencing the quality and stability of the grinding process and repeatability of its results is through controlling the machining allowance and method of coolant provision. This issue is of exceptional importance from the perspective of costs related to buying, using and maintaining coolants, as well as the impact the disposal of these fluids - classified as hazardous waste - has on the environment. The construction of a small-dimensional sandwich grinding wheel with a centrifugal coolant provision system was described against the background of known methods of limiting grinding fluid flow rate, usually involving its effective provision into the machining zone. Results of simulation analyses regarding the influence of grinding speed and diameter, as well as the number of channels on the speed of the coolant outflow through holes in the grinding wheel arbor were presented. Taking into consideration the results of simulation, a prototype of the sandwich grinding wheel was made and a number of experimental tests on the process of internal cylindrical grinding of steel 100Cr6, with 62 ± 2 HRC hardness, were carried out. The experiment results obtained were then compared with the results obtained when using the flood cooling method. The test results showed that application of the sandwich grinding wheel allows for a fivefold limiting of the grinding fluid flow rate, from 5.0 to 1.0 l/min, with simultaneous limitation of the machined surface roughness and without considerable influence on the grinding power. The last part of the article also presents an improved construction solution which facilitates centrifugal coolant provision.