Stationary wheels can be balanced with one or more counter-weights, whose positions are determined when the grinding tool hangs freely on a cylinder rod through its inner hole [DIN05, KLOC09, p. 284]. Wheels with flanges have a notch on the circumference to hold two or three sliding blocks [WECK05, p. 245 f.].
5.2.2.1 Balancing of Rotating Wheels Outside of the Machine Tool
Tool grinding wheels are often balanced on their exchangeable spindle outside of the machine tool. Higher process stability, higher workpiece surface quality, and longer grinding wheel life are advantages of grinding tool balancing [MPM12]. A balancing device can detect imbalance mass and angular position.
5.2.2.2 Balancing of Rotating Wheels in the Tool Spindle by Hydro Compensators
Hydro compensators use the cooling lubricant present in the machine tool. These balancing devices have several compensation chambers around the grinding wheel axis either inside the tool spindle or as balancing container on the front face of the spindle [KLOC09, p. 285]. The chambers are filled with the cooling lubricant in opposing direction to compensate the detected imbalance [KLOC09, p. 285]. One disadvantage is that the system has to be reset when one chamber has been filled completely.