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Is this a cure for creeping cages?

01 March, 2000

Is this a cure for creeping cages?

SKF claims to have come up with a cure for the phenomenon known as "cage creep" which can reduce the working lives of precision linear rail guides.

Cage creep occurs when uneven pre-loading or poor rail alignments cause the cage to edge along the vee of the guideway. The housing makes contact with the guideway endstops and the elements begin to skid rather than roll. The problem is particularly acute for vertically mounted guides, where gravity complicates matters.

SKF`s answer is to enclose a small plastic sprocket in the centre of the plastic moulding that forms the cage. Corresponding notches are machined into the bottom of the guideway vees so that they mesh with the sprocket.

This creates, in effect, a low-duty rack-and-pinion drive as the guideway moves, generating a synchronised movement which optimises the cage position throughout the stroke of the rail.

SKF is offering the patented Anti Creep System (ACS) as an option on its LWRE range of precision linear guideways. It can be used interchangeably with conventional rails with three cross-sectional dimensions: 18mm by 18mm; 31mm by 15mm; and 44mm by 22mm.