A torque sensor (2) comprises a magnetoelastically active element (4), and a magnetic sensor (6) responsive to the field of the magnetoelastically active portion. The magnetoelastically active portion comprises a ring of material (4) endowed with an effective uniaxial magnetic anisotropy such that the circumferential direction is the easy axis, and magnetically polarized in a substantially circumferential direction. The ring (4) is attached to the torqued member (8), such as a rotating shaft, so that application of a torque to the shaft is transmitted to the ring. A magnetic field vector sensor (6) is mounted in a fixed position relative to the ring (4) and oriented so that it responds maximally only to the field due to the axial magnetization components of the ring (4). The output of the sensor (6) is thus proportional to the change in orientation of the magnetization resulting from torque applied to the shaft (8) and transmitted to the ring (4). The magnetoelastically active portion (4) may include two or more axially distinct, magnetically contiguous, oppositely polarized circumferential regions (104, 105).

Circularly magnetized non-contact torque sensor and method for measuring torque using same

A magnetoelastic torque sensor (2) for providing an output signal (24) indicative of the torque applied to a member about an axially extending axis of the member (11), comprising, a first magnetoelastically active region in the member, the region being magnetically polarized in a single circumferential direction and possessing sufficient magnetic anisotropy to return the magnetization in the region, following the application of torque to the member, to the single circumferential direction when the applied torque is reduced to zero, whereby the magnetoelastically active region produces a magnetic field varying with the torque. Magnetic field sensors are mounted proximate to the magnetoelastically active region (ABC) and oriented with respect thereto to sense the magnitude of the magnetic field at the sensors (6) and provide the output signal in response thereto (24). At least the magnetoelastically active region of the member is formed of a polycrystalline material wherein at least 50 % of the distribution of local magnetizations lie within a 90 °C quadrant symmetrically disposed around the single circular direction and having a coercivity sufficiently high that the field arising from the magnetoelastically active region does not magnetize regions of the member proximate to the magnetoelastically active region to give rise to parasitic magnetic fields which are of sufficient strength to destroy the usefulness, for torque sensing purposes, of the net magnetic field seen by the magnetic field sensor means.

Collarless circularly magnetized torque transducer and method for measuring torque using same

Shutter timing apparatus

A torque sensor comprises a magnetoelastically active element, and a magnetic sensor, such as a Hall effect sensor, responsive to the field of the magnetoelastically active portion. In the preferred embodiment, the magnetoelastically active portion comprises a ring of material endowed with an effective uniaxial magnetic anisotropy such that the circumferential direction is the easy axis, and magnetically polarized in a substantially circumferential direction. The ring is attached to the torqued member, such as a rotating shaft, so that application of a torque to the shaft is transmitted to the ring. The torque on the ring reorients the circumferential magnetic orientation of the ring, producing a helical magnetic orientation having both circumferential and axial components. A magnetic field vector sensor is mounted on a flux collector in a fixed position relative to the ring and oriented so that it responds to the field arising from the axial component of the magnetization within the ring. The output of the sensor is thus proportional to the change in orientation of the magnetization resulting from torque applied to the shaft and transmitted to the ring.

Method for producing a circularly magnetized non-contact torque sensor

A torque/power sensor (2) for providing an output signal indicative of the torque applied to or the power transmitted by a rotating torqued member (8) comprises a magnetoelastically active element (4) for producing a magnetic field varying with the applied torque and a field modulating means (25) for modulating the magnetic field in a periodic manner which is indicative of the speed of member rotation A magnetic field vector sensor (6), such as a Hall effect sensor, senses the amplitude of the modulated field for providing an output signal which is linearly indicative of the torque applied to the rotating member (8) Alternatively, a magnetic field vector sensor in the form of a coil senses the amplitude of the time rate of change of the modulated field for providing an output signal which is linearly indicative of the power transmitted by the rotating member (8) The field modulating means (25) preferably comprises at least one ring having some uniformly spaced salient features, such as a gear-like teeth around the periphery thereof

Circularly magnetized non-contact torque and power sensor and method for measuring torque and power using same

Magnetostrictive stress-responsive device and system embodying the same

The theory of the development of torque in a hysteresis motor is analyzed from both the hysteresis lag angle and total loop energy points of view. A new development, comprising the use of a closed slot stator in co-operation with a hysteresis rotor, which permits building hysteresis motors of high power output at high efficiency is explained qualitatively and supplemented by considerable quantitative experimental data. A new method of stator construction, permitting the use of closed slot stator laminations assembled on a mandrel with non-magnetic bearing supporting spiders, wound externally in either a d-c type of armature winding machine or with form-wound coils, impregnated with a thermosetting resin and baked to form a unitary structure, is described. The electrical design of the machine is covered and quantitative data on both design details and operating characteristics are given on several models.

The hysteresis motor-advances whick permit economical fractional horsepower ratings

This invention relates to apparatus for suspending an object in the air and effecting substantially instantaneous release thereof when desired, and more particularly to a device for holding and releasing aerial bombs. One of the objects of this invention is to provide apparatus for suspending...

Apparatus for suspending and releasing objects

System for and method of controlling hysteresis motors

This invention relates to an electrical system for indicating the course of a mobile vehicle and, while it is of general application, it is particularly suitable for use in indicating directly on dials the distances covered by a. vehicle, such as an aircraft, in the north-south and east-west...

Herbert C Roters

Papers

Magnetostrictive stress-responsive device and system embodying the same

The hysteresis motor-advances whick permit economical fractional horsepower ratings

Apparatus for suspending and releasing objects

System for and method of controlling hysteresis motors

Electrical position indicating system