Posted to News on 12th Nov 2007, 22:05
New anti-cage-creep system uses brass involute gears
SKF is launching a 'second edition' version of the Anti-Creep System (ACS) technology for its extensive range of precision rail guides. Incorporating tough involute brass gears for smoother, more accurate performance and quieter operation, the enhanced ACS technology eliminates the problems associated with cage creep - such as friction and misalignment - within caged roller units, thereby providing improved reliability, consistent accuracy and repeatability, and longer operating life.
The latest brass ACS technology has been introduced to complement SKF's existing anti-creep devices, which incorporate robust plastic alignment mechanisms. Although these devices provide a high degree of accuracy and reliability in many applications, the new brass mechanism has been introduced demanding applications, especially where extremely rapid operating speeds and rates of acceleration are required or where operating conditions are especially hostile.
Cage creep is a phenomenon common in many linear rail guides, where sustained use at high speeds or under conditions of heavy load can cause the ball- or roller-retaining cage to drift from its original position. This can lead to increased wear, reduced accuracy and repeatability and, in a worst-case scenario, complete unit failure.
To overcome this, the latest anti-creep system is based on a conventional design of roller cage with the addition of a drive element and specially shaped control gear, the teeth of which mesh with the rail gearing to ensure that the cage unit remains correctly positioned at all times.
Due to the use of an involute gear profile, smooth contact is maintained between the teeth as they mesh, providing a more stable and durable operation and preventing the cage retainer from misaligning, even under high levels of acceleration. In addition, the latest ACS minimises torque and speed variations, while offering a long service life with virtually no maintenance required.
The latest ACS technology has been tested by SKF to maximum speeds of 3.2m/s and 16g acceleration over more than 20 million operating cycles, using an eccentric mass and uneven payload to mimic real-life applications.
