Patent ID: 6705761
Filing Date: 2004-03-16
Classification: F16C,G01D,G01L,G08C

Abstract:
A bearing, comprising: a first part provided with a first coil, a second part rotatable with respect to the first part about a bearing axis and being provided with a second coil which is electromagnetically coupled to the first coil, the first and second coil being magnetically enclosed by a first covering and a second covering, respectively, the first covering being fixed to the first part and the second covering being fixed to the second part, wherein at least one facing end of the first and second coverings is provided with at least one recession extending in an axial direction to define a variable air gap that varies when the first part and second part rotate with respect to each other to provide a change in electromagnetic coupling indicative of relative rotational speed of the first part and the second part.