Fine grinding is also used when workpieces require both surfaces to have plane parallelism, but with more precision than can be achieved with double-disk grinding. Workpieces are placed in carriers that have teeth on the outside diameter. An inner pin ring rotates the carriers as they shift on a stationary outer pin ring in an orbiting manner. Machining takes place between two rotating grinding wheels. The optimal machining force is applied by the upper wheel, which is mounted on an oscillating pendulum. Fine grinding’s central feature is that a fixed number of parts can be processed simultaneously, or in batches.
Each of these machining technologies has its particular strengths. For maximum stock removal as well as output of finished workpieces, double-disk grinding is preferred. For example, within large-scale production, single cams can be ground with a cycle time of fewer than 0.5 seconds with a continuous-feed loading system.
However, for maximum precision and size accuracy, fine grinding is preferred. Hydraulic components, for example, can be finished with an accuracy of ± 0.001 mm.