Posted to News on 25th Mar 2007, 16:47
Single-stage economy gearboxes 'fit all servo motors'
ZF is launching a new range of compact WTE (WT Economy) single-stage right-angled gearheads for OEM designers and maintenance engineers who require high levels of performance and flexibility from smaller, more cost-effective units. An innovative one-piece aluminium body offers lightweight and extremely rigid operation and allows the four ratios available to be housed in the same sized unit. In addition, universal mounting, and the ability to fit all servo motors, enables motors to be upgraded without requiring gearbox replacement, and sealed-for-life internal gearing eliminates the need for maintenance.
By integrating the high-torque and low-backlash Gleason hypoid tooth design and high-quality taper roller bearings, the new WTE gearheads offer accurate operation even in applications where there are high axial and radial loads. The innovative body design is machined from a single aluminium casting, offering high levels of torque from a one-piece, lightweight, compact unit that lends itself to use in highly dynamic servo applications. Levels of rigidity are also improved by the one-piece design, and the WTE range covers four ratios from 5:1 to 15:1 in one size of housing, thereby cutting design time and facilitating maintenance or upgrades.
To ensure the new WTE gearheads are successful in the marketplace, ZF has designed the units to be compatible with the maximum number of servo applications in industries ranging from packaging to assembly. The gearheads come with two shaft options: solid shaft with input flange/coupling and a choice of output flange mountings. Designed to be mounted in any orientation and to fit almost any motor, the input flange and coupling assembly allows motors to be replaced with higher power versions or larger frame sizes, without the need to replace the gearhead.
Low vibration, backlash and losses
A coupling-based torque transfer assembly also allows adjustments to be made for minimising machine vibration. By shrink-fitting the input shaft and gearwheel into the unit, fretting and levels of backlash are reduced to a minimum (backlash down to 6 arc-min or less). The compact design of the WTE gearheads is partly due to a novel hypoid tooth pattern that permits high ratios from a smaller bevel gear system. Optimised for greater strength, the Gleason hypoid gears also keep inertia output torque to a minimum and ensure maximum transmission (minimal output torques up to 140Nm). The design also saves on energy costs by offering operational efficiency of 96 per cent and provides a very small moment of inertia at start-up.
The range can cater for applications that require input speeds of up to 5000rpm while creating low noise levels - between 66 and 68dB or less when running at 3000rpm. WTE gearheads are approved for use in Atex Zone II environments and are sealed for life, which avoids the need for lubrication and offers a long nominal service life, typically 15,000 hours. This is true even in adverse environments where an enclosed design, with IP64 ingress protection, guarantees reliable performance.
