Patent ID: 7639004

Claim:
An apparatus for measuring the relative displacement between a first shaft and a second shaft, comprising: a first rotor assembly being coupled to the first shaft and being centered on an axis; at least one magnet having a magnetic field and being disposed on the first rotor assembly; a second rotor assembly being coupled to the second shaft, the first and second rotor assemblies being coaxial, the second rotor assembly having a first stator plate and a second stator plate, the first and second stator plates having a circular base section and a plurality of teeth extending from the base section in a direction radial of the axis; a flux collector arrangement having a first collector and a second collector, the first and second collectors having a curved first surface, the curved first surface of the first and second collectors being spaced from an outer rim of the base section of the first and second stator plates, respectively, the first and second collectors having a second surface, the second surface of the first collector and the second surface of the second collector being parallel and forming a gap; and a sensing device disposed within the gap for sensing a magnetic flux of the magnetic field.