Couplings complement servo/gearbox combos

Edited by the Engineeringtalk editorial team Feb 9, 2005

A new range of metal bellows and elastomer based couplings provide a flexible, but torsionally rigid interface between servomotors and their range of gearboxes.

ZF Industrial has launched a new range of metal bellows and elastomer based couplings that provide a flexible, but torsionally rigid interface between servomotors and their range of gearboxes.

Available individually or ready fitted, the couplings allow for servo axle speeds up to 50,000rev/min and backlash free operation even under high loads.

Designed to meet the demands of modern machines, systems and tools, couplings can simultaneously compensate for angular, axial and radial misalignment therefore speeding up installation, facilitating product replacement and reducing downtime through increasing the operating life of system components.

The couplings, manufactured by R and W, have low mass and weight, reducing the moment of inertia and making them ideal for high-speed servo applications where rapid acceleration/deceleration cycles exist.

Units operate completely backlash free and are available with torque capacities ranging from 15 to 10,000Nm.

Shaft extension variations to span large gaps between motor and gearhead are included in the range and stainless steel versions are also available that ensure compatibility with systems in food, medical and chemical industries.

The couplings are available in two basic designs: the steel bellows version and the elastomer spider based coupling.

Steel bellows couplings offer high torque capacities (up to 10,000Nm), making them ideal for use with ZF's PG, PGE, SWG and WT Series gearheads in highly dynamic servo applications such as NC/CNC machine tools, robotic drives as well as packaging and positioning systems.

For applications that require torque overload protection, steel bellows couplings are also available with inbuilt single/multi position, load holding and free-wheeling functions that will disengage within 1-3ms.

Elastomer based designs are more suited to ZF's PowerGear, ValueGear and DesignGear boxes when used in CNC milling and turning applications that need a high degree of damping.

The elastomer versions are available in three different shore values to meet the correct damping requirements of the application and allow for a smaller distance between motor and gearbox for situations where space is restricted.

ZF can supply both bellows and elastomer unit as split hub versions for setups where shaft ends are not easily adjusted.

Tapered conical versions are available which offer higher clamping forces without keys for higher torque systems.

For lower torque applications, press fit designs are offered that avoid the need for users to access fasteners through the flange hole, therefore reducing fitting/maintenance time.

Conical shaft compatible versions for Fanuc motors are also available and units with expanding tapered clamping elements can be supplied to fit hollow bores.