Abstract: A method for producing a low-hysteresis magnetoelastic element comprising applying a magnetoelastic material onto a metal substrate. After the magnetoelastic element is securely bonded to the underlying shaft, a reduction in the outside diameter of the shaft draws the magnetoelastic element radially inward causing it to occupy a smaller volume. This process provides the magnetic anistropy required for the sensor to operate properly, and also results in a densification of the magnetoelastic element making it inherently stable. Several methods of reducing the outside diameter of the shaft to draw the magnetoelastic element radially inward have been devised. Prior to deposition of the magnetoelastic material, the outside diameter of a hollow shaft is elastically expanded by applying force to its inside diameter. This is accomplished by using an expanding insert, by pressurizing the cavity within the shaft, or by inducing a managed thermal expansion of the shaft prior to material deposition.

Abstract: A coupler acts as an interface between a torque element of a torque sensor and a shaft receiving an applied torque. A portion of the shaft is allowed to twist freely inside the element, and the coupler transfers a portion of the torsion forces in the shaft to the element. The element deforms and generates a magnetic field or other torque response corresponding to the applied torque in the shaft. The applied torque can then be determined based on a relationship between the torque in the shaft and the torque in the element. Reducing the torsion forces applied to the element allows the element to measure higher applied torques without permanently deforming.

Abstract: A magnetic assembly apparatus and method for optimizing the magnetic field characteristics generated by the magnetic assembly used in active speed sensors. The magnetic assembly comprising a plurality of pole pieces inserted within a tubular magnet. By optimizing the geometry of the magnetic assembly, the region of usable magnetic field is altered to accommodate the switching characteristics of a given magnetic sensing device allowing the use of low cost sensing devices.

Abstract: A coupler acts as an interface between a torque element of a torque sensor and a shaft receiving an applied torque. A portion of the shaft is allowed to twist freely inside the element, and the coupler transfers a portion of the torsion forces in the shaft to the element. The element deforms and generates a magnetic field or other torque response corresponding to the applied torque in the shaft. The applied torque can then be determined based on a relationship between the torque in the shaft and the torque in the element. Reducing the torsion forces applied to the element allows the element to measure higher applied torques without permanently deforming.