Drives and Controls Magazine

Self-lube ballscrews keep turning for 20,000h

01 April, 2003

Self-lube ballscrews keep turning for 20,000h

Thomson, the linear motion company now owned by Danaher, has developed a new form of self-lubricating ballscrew that, it claims, will operate continuously for more than 20,000h.

Traditionally, ballscrews have had to be lubricated with grease or oil every 800—1,000h of operation. Thomson`s new SL system (above) lubricates the bearing track directly by transferring a thin film of oil from a patented solid, oil-filled polymer matrix.

The liquid lubricant, in the enclosed polymer matrix, "bleeds" onto the bearing track through a network of capillaries. The grease conventionally used to lubricate ballscrews typically contains 35% oil suspended in a thickening agent. Thomson`s SL system is contained in the ball nut housing, and holds 70% oil in a much larger reservoir, allowing lubrication intervals to be extended ten-fold.

Thomson claims that the new system does not affect operating temperatures or transfer speeds. It adds that the benefits for users will include: lower noise levels; reduced production of particles and release of lubricants; and extended maintenance intervals and product lives.