Patent ID: 7021160

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, each of the first and second stator plates having an upper surface and a lower surface, the upper and lower surfaces being parallel, the first and second stator plates having a plurality of teeth extending in a direction radial of the axis, each tooth having upper surface and a lower surface, the upper surface of each tooth being planar with the upper surface of the respective stator plate, the lower surface of each tooth being planar the lower surface of the respective plate, the first and second stator plates forming a gap between the lower surface of the first stator plate and the upper surface of the second stator plate, the gap having a uniform thickness; and, a sensing device disposed within the gap for sensing a magnetic flux of the magnetic field.