5.2.1 Flanges
Cylindrical grinding wheels are often mounted on a hub and clamped between flanges [ROWE09, p. 49]. The adapter flange consists of a fixed flange, a lose flange, and head screws [DIN06]. Standards define the flange design, e. g. BS 4581:1970, and DIN ISO 666 [DIN06]. Some flanges have special features such as a centering section with three lobes in an angle of 120° to ensure a centricity of 2 ^m and below [HIME08].
The flanges need to provide friction to accelerate and decelerate the grinding wheel and overcome grinding forces [ROWE09, p. 50]. Four forces act during wheel usage: force of gravity, centrifugal force due to speed and imbalances, contact force between workpiece and tool, and lateral force at the median clamping diameter resulting from the tangential cutting force [DIN06]. The minimum clamping force needs to counter slipping of the grinding wheel; the maximum clamping force is defined by the strength of the grinding wheel material and the stiffness of the clamping device [VOLK72]. Volkmann [VOLK72] calculated appropriate clamping forces and justified the theoretical anaysis with a friction test. The clamping force for industrial applications can be calculated from guidance values in [DIN06].
An interim layer between the flanges and the conventional wheel prevents local stresses on the abrasive structure [ROWE09, p. 49]. The interim layer can be a ring and has to be made of a flexible material that has to match the application requirements, e. g. paper [DIN07]. As example, the material has to be water resistant if the grinding operation is conducted with an emulsion [DIN07].
