How does the ratio of run time to total cycle time affect the design and layout of a worm gear jack system? Taken from the white paper “How to Size a Worm Gear Screw Jack,” this post looks at what a designer has to take into account to properly and safely answer that question.
Some of the mechanical energy input to a worm gear screw jack is converted into heat caused by friction. The duty cycle is limited by the ability of the worm gear screw jack to dissipate heat. An increase in temperature can affect the properties of some components resulting in accelerated wear, damage and possible unexpected failure.
Recommended duty cycles at max horsepower are:
- Ball screw jacks = 35% (65% time off)
- Machine screw jacks = 25% (75% time off)
The choice between a ball screw jack and a machine screw jack can dictate size. Ball screw jacks are often chosen for their efficiency, allowing for an increased duty cycle and a smaller size jack to move a given load.