Drives and Controls Magazine

Bearing angle measurement is untouchable

01 July, 2002

Bearing angle measurement is untouchable

INA has developed a non-contact angle measuring system designed to be integrated into axial-radial bearings whose position it can measure to an accuracy of a few seconds. The magnetorestrictive (MR) sensor is wear-free and is not affected by the tilt or position of the bearing.

Two measuring heads, each with self-compensating electronics, are used with a scale electroplated onto the bearing shaft washer. An evaluation circuit uses vector addition to calculate the effective angle from the two sensor signals. Unlike systems using magnetic heads, the MR sensors can measure angles when the bearing is stationary.

The angle measuring system can be fitted to INA`s YRT bearings with bore diameters of 200, 260 and 325mm. It is said to be easy to fit, with no alignments being needed. It has an operating temperature range of 0-50°C and is not affected by vibration or lubricants.