With servos becoming more and more widely used, an increasing number of motion control applications are placing a high premium on high-precision performance and better overall control. Rick Covault, sales manager at Nabtesco, says his company is seeing a trend to more servo control and use of higher precision gearboxes, in part driven by a greater focus on quality control and reporting requirements. As a product category, motion performance requirements for gearheads are becoming more stringent as applications put priority on limiting dynamic motion errors, higher system accuracies and repeatable performance. Recently introduced gearhead products are emphasizing near-zero backlash capabilities, increased torque output and compact, space-saving and economical designs.
Planetary servo gearheads increase torque capability
The torque ratings of single stage Neugart E-series planetary servo-gearheads (ratios of 3:1, 4:1 and 5:1) have increased by up to 250 percent. The new design increases torque density by using additional (up to five) planet gears, compared to conventional designs which typically utilize only three planets. Using more planet gears increases the torque load ability, torque density and provides more rotational stiffness, which reduces the amount of rotational wind-up and lost motion. The torque density of the new gearheads may also allow designers to downsize their gearbox selection and use more compact, space-saving and economical gearheads.
Hollow Shaft / Near-Zero Backlash Reduction Gear
A near-zero backlash RV-C gearbox from Nabtesco provides flexibility and performance in an extremely compact, highly rigid, torque-dense design. The patented design provides a hollow pass-through, up to 5 inches in diameter, for running cables and creating space-saving designs. The unit provides backlash of less than 1 arc-min, large overhung moment support, ratios up to 300:1 and a large E-Stop capacity. These reducer products incorporate a set of large, internal angular support bearings that provide large moment capacities and negate the need for external support devices. The component version RV-C is available in a traditional gearhead RD-C version.
New High-Precision Helical Planetary Gearheads
New helical planetary precision gearheads from Boston Gear are designed for direct attachment to popular servo and stepper motors. Balanced planetary kinematics at high speeds, combined with associated load sharing, make planetary-type gearheads ideal for servo applications. These new products also feature patented planet carrier and input/output sealing designs, plus special heat and surface treatments. All exposed gearhead parts are stainless- steel and housings are available in black anodized aluminum, or can be epoxy-coated for wet and washdown applications. A five-year warranty covers seals, bearings and all elements for the gearheads. The new products have been designed for packaging, medical, material handling, robotics, automotive and other industrial applications.