Wear Life of Power Screws
The wear life of power screws is a function of:
- and other factors.
The operating loads listed in the Screw/Nut Engineering section for each screw series provide acceptable wear life for most applications.
Wear in a power screw is generally in proportion to usage. Each movement of the screw surface against the mating nut surface removes a microscopic amount of material, usually from the softer nut material. As these wear, increments add up over time, and backlash increases, the nut threads become thinner. When the shear strength of the remaining threads is exceeded by the load, failure occurs.
Identifying Power Screw Wear
Although their wear life is not as predictable as Ball screws, well-lubricated power screws, without side loads or moment loads, can provide excellent service lives for many applications.
- Heavy loads and duty cycles that generate significant amounts of heat will cause material and lubricant breakdown and should be avoided.
- Every power screw application is unique in terms of loads, environment, duty cycle, etc.
- Operational and life testing of prototypes is highly recommended especially for OEMs anticipating large volume production.
Customers are encouraged to contact Roton’s application engineers who are available for consultation and to discuss wear life of power screws and objectives for specific applications. Often, a short evaluation early in the application development can save many hours of design revision and testing.