Power Chuck for Advanced Turning Center Spindles

The DURO-A RC power chuck from Röhm Products of America (Suwanee, GA) reduces setup times considerably thanks to a quick jaw-change system that allows the jaws to be adjusted, reversed, or swapped out in just 50 seconds. The chuck also comes with a three-year warranty and provides a competitive price-performance ratio. Designed to meet the needs of manufacturers as turning centers with integrated spindle motor technology become more common, this power chuck unlocks the full potential of those machines. Traditional power chucks often cannot keep up with newer spindles’ rotational speeds and acceleration/deceleration rates due to the heavy weight and loss of dynamic clamping force of those chucks. To overcome this challenge, the DURO-A RC billet steel body has a compact, lightweight design, with an overall height that is reduced by 14 percent. It boasts centrifugal force compensation that allows for fast speeds and feeds, as well as power consumption savings of up to 17 percent.

The chuck’s interchangeable back plate further ensures convenient adaptability to fit to a wide range of lathe spindles. A decisive competitive factor, the quick-change capabilities of this power chuck unlock significant process improvements by eliminating a common bottleneck in manufacturing.

Many modern machine tools lose production potential because their operators continue to rely on 40-year-old chuck designs with limited flexibility, poor response to clamping force and equally poor torque transmission. The bulky dimensions and heavy weights of these old-fashioned chucks restrict workpiece size as well as machine performance. Röhm has developed an advanced manual chuck design that allows shops to take full advantage of today’s productive machine tools: The DURO-TA XT chuck delivers extraordinary clamping force via a special guideway concept and key bar system that – compared to standard lathe scroll chucks at equal levels of torque – provide more-reliable torque transmission and more than twice the gripping force: up to 290 kN (213,893.02 ft-lb). This new design also reduces runout by 50 percent compared to lathe scroll chucks of the same size and provides 50 percent better repeatability.

DURO-TA XT chucks begin with a proven DURO-TA base body and add innovative elongated guideways that produce flexible, quick, easy conversion between small and large workpieces. Because of their superior design, these chucks can clamp parts that are larger than themselves – a capability that offers significant benefits on popular five-axis milling machines with large rotary tables and trunnions. Through the increased clamping capacity of jaw extensions, DURO-TA XT construction cuts up to 75 percent of weight compared to other large chucks, clamping high workpiece weights securely and helping shops make full use of their machines’ potential. For example, a 10 in DURO-TA XT chuck with a clamping range of 8 mm to 253 mm (0.315 in to 9.960 in) expands that range to 28 in with the addition of extended jaws. This flexibility enables shops to maintain fewer chuck sizes in their inventory. The same chuck size clamps smaller workpieces because its guideways easily dismount.

At the same time, these chucks offer up to 78 percent reduction in overall height for better access to workpieces and minimal contour interference. They also achieve between 65 percent and 75 percent weight reduction over other large chucks. By comparison, a typical 32 in chuck weighs approximately 500 kg (1,102.3 lb) without top jaws, mounting plate or workpiece, and quickly exceeds the 700 kg to 800 kg (1,543.2 lb to 1,763.7 lb) weight capacity of the machines to which it attaches. In many cases, using the DURO-TA XT imposes workpiece limitations – not from the chucks, but from the weight requirements of the machines themselves and the impact of centrifugal force on large parts at high speeds. Unlike other large chucks, these can work at turning speeds up to 800 rpm that is compatible with the 500 rpm and lower speed limits on five-axis machines, trunnions and rotary tables. With maximum gripping applied, these chucks still maintain one-third of their gripping forces as residual gripping force when fitted with their heaviest jaws.

Rapid adjustment capabilities and a flexible selection of jaw options make DURO-TA XT a viable choice for manufacturing ring parts and light castings. Options include stepped and unstepped, draw-down, claw-type and reversible jaws, as well as interchangeable clamping inserts with claws, serrated toothing or heat-treatable surfaces. Direct guideway mounting on the DURO-TA base body and a proven dirt-cover design helps keep DURO-TA XT chucks clean, protecting them against chips while guaranteeing extremely high rigidity and stability. For shops that only process small workpieces, the DURO-TA XT is available without guideways. Additional options include T-slot and pallet mountings, as well as the ability to mount directly to the spindle on vertical turning centers.

These chucks are available in diameters of 1,250 mm (49.213 in), 1,000 mm (39.370 in) and 750 mm (29.528 in), with external clamping ranges of 220 mm to 1,190 mm (8.661 in to 46.850 in), 220 mm to 995 mm (8.661 in to 39.173 in) and 145 mm to 715 mm (5.709 in to 28.150 in) respectively, using extended jaws. With standard jaws, the three chuck sizes clamp 8 mm to 253 mm (0.315 in to 9.961 in), 12 mm to 323 mm (0.472 in to 12.717 in) and 40 mm to 501 mm (1.575 in to 19.724 in). Other sizes and configurations can be created for customer requests.

Röhm Products of America, 2500 Northlake Drive, Suwanee, GA 30024, 770-963-8440, Fax: 770-963-8407, www.rohm-products.com.