Power Chucks For Grinding Applications

The product lineup of workholding solutions from Forkardt North America includes the KCHP series of high-precision power chucks, with integral design and construction features that shield the internal mechanisms from harsh grinding environments. With a sealed chuck body to prevent sludge contamination and a permanent oil-filled reservoir for lubrication, the series is said to provide virtually maintenance-free operation for precise centric chucking-jaw positioning accuracy of 2 µ and TIR repeatability also in the 2 µ range—in external or internal cylindrical grinding operations. The series of chucks also includes the company’s wedge hook mechanism that eliminates backlash and provides optimal clamping pressures. The chucks offer control of variable pressure levels for secure clamping on heavy workpieces or to safely hold delicate, thin-walled parts without deformation. Overall accuracy and efficiency are further improved with the inclusion of a ball-and-pocket positioning system that ensures fast, precise jaw changes without the need for adjustments and zeroing-in procedures. The series of chucks is offered in three operating configurations, the first being a standard cylinder/draw-tube actuated version with OD sizes from 110 to 250 mm in diameter and permissible maximum speeds of 2,500 to 1,500-rpm, respectively. The second variation of chucks, the VKCHP models, are front-end-operated power chucks, which use rotary air connections through the spindle and are designed for confined work spaces. These chucks, with sizes from 110 to 198 mm in diameter, feature an integral power-operated cylinder with safety valves that sustain clamping forces, even in the event of pneumatic pressure loss, the company says. This variation of chucks also has pneumatic ports for gripping and release actuation, and a third connection for coolant delivery or air sensing. The third chuck configuration is the VEKCHP, a series of four chuck sizes, from 110 to 198 mm in diameter, with fully front-end power operation using direct air supply. These chucks include an integral cylinder and air supply connectivity ring, and they feature safety valve construction to maintain secure clamping if pressure is lost. These chucks are for use on grinding machines without spindle openings or in confined areas.