Patents Assigned to Magnetoelastic Devices, Inc.
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Patent number: 6490934Abstract: A magnetoelastic torque sensor for providing an output signal indicative of the torque applied to a member includes a ferromagnetic, magnetostrictive, magnetoelastically active region on or in the member, the region begin proportionally subjected to the torque applied to the member. The region is endowed with an effective uniaxial magnetic anisotropy having the circumferential direction as the easy axis and is magnetically polarized in a single circumferential direction. When torque is applied to the member, the magnetoelastically active region produces a magnetic field varying with the torque, which field is sensed by magnetic field sensors arranged proximate the region.Type: GrantFiled: June 20, 2001Date of Patent: December 10, 2002Assignee: Magnetoelastic Devices, Inc.Inventor: Ivan J. Garshelis
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Patent number: 5708216Abstract: A torque sensor for providing an output signal indicative of the torque applied to a rotating torqued member comprises a magnetoelastically active element for producing a magnetic field varying with the applied torque and a field modulating means for modulating the magnetic field in a periodic manner which is indicative of the speed of member rotation. A magnetic field vector sensor, 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. The field modulating means preferably comprises at least one ring having some uniformly spaced salient feature, such as gear-like teeth, around the periphery thereof. In one embodiment, the magnetoelastically active element 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.Type: GrantFiled: July 23, 1996Date of Patent: January 13, 1998Assignee: Magnetoelastic Devices, Inc.Inventor: Ivan J. Garshelis
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Patent number: 5706572Abstract: 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.Type: GrantFiled: June 7, 1995Date of Patent: January 13, 1998Assignee: Magnetoelastic Devices, Inc.Inventor: Ivan J. Garshelis
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Patent number: 5520059Abstract: 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 one 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 therting. 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 in a fixed position relative to the ring and oriented so that it responds maximally only to the field due to the axial magnetization components of the ring.Type: GrantFiled: June 2, 1994Date of Patent: May 28, 1996Assignee: Magnetoelastic Devices, Inc.Inventor: Ivan J. Garshelis
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Patent number: 5465627Abstract: 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 only to axial magnetic field components of the ring.Type: GrantFiled: March 24, 1994Date of Patent: November 14, 1995Assignee: Magnetoelastic Devices, Inc.Inventor: Ivan J. Garshelis
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Patent number: 5351555Abstract: 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.Type: GrantFiled: July 29, 1991Date of Patent: October 4, 1994Assignee: Magnetoelastic Devices, Inc.Inventor: Ivan J. Garshelis