Harmonic Drive
Machining Centre NC Rotary Table
High precision output bearing
Input shaft
Increasingly Harmonic Drive® gears are being used to replace worm or planetary gears in the precise rotary axes of machine tools. High accuracy is usually only possible with worm or planetary gears that are pre-loaded to eliminate backlash. The natural pre-loading of Harmonic Drive® gears, combined with their high efficiency means that the temperature rise during operation is much lower, with positive results for the stable positioning accuracy of the machine.
Given that assembly and lubrication is carried out according to the manufacturer's recommendations there is no increase in backlash with a Harmonic Drive® gear during its operating life. This means there is no need to re-adjust gears to remove backlash, as is common with worm gears or planetary gears. In this design example, the Flexspline of a HFUC component set acts as output element. The output flange is supported by a precision output bearing (needle-roller bearing). The Circular Spline, as fixed element, is located in the machine housing.
The Wave Generator, as input element, is driven via a toothed belt. To keep the height of the table to a minimum the motor is mounted in parallel to the gear. In this application the cutting forces are not very high, so there is no need for output-side clamping of the table. In the event that very high cutting forces must be held it is advisable to use a curvic coupling to lock the output flange.
