US 11,715,587 B2
Rotary variable differential transformer
Paresh Sanchihar, Bangalore (IN); Subramanian Esakki, Bangalore (IN); and Vijayshekhar Araganji, Bangalore (IN)
Assigned to HONEYWELL INTERNATIONAL INC., Morris Plains, NJ (US)
Filed by Honeywell International Inc., Morris Plains, NJ (US)
Filed on May 24, 2019, as Appl. No. 16/422,005.
Prior Publication US 2020/0373056 A1, Nov. 26, 2020
Int. Cl. H01F 38/18 (2006.01); H01F 21/04 (2006.01); H01F 27/28 (2006.01); G01D 5/22 (2006.01); H01F 41/02 (2006.01); H01F 27/02 (2006.01)
CPC H01F 21/04 (2013.01) [G01D 5/2291 (2013.01); H01F 27/02 (2013.01); H01F 27/28 (2013.01); H01F 41/02 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A rotary variable differential transformer for measuring angular displacement of a shaft, the rotary variable differential transformer comprising:
a stator housing:
a primary coil configured to receive an alternating current;
a first secondary coil electromagnetically coupled to the primary coil; and
a second secondary coil electromagnetically coupled to the primary coil; and
a rotor positioned concentrically within the stator, wherein the rotor is configured to receive a shaft and rotate with the shaft while the stator remains stationary;
wherein the primary coil is positioned at a first radial position within the stator spaced between about 90 to 150 degrees from each of the first secondary coil and the second secondary coil;
wherein the rotor is configured with a magnetically permeable arcuate section extending from 180 to 270 degrees of the entire circumference of the rotor, such that 90 to 150 degrees of the circumference of the rotor defines a base portion having a smaller radius than the magnetically permeable arcuate section; and
wherein the stator further defines an airgap between 0.001 and 0.010 inches measured between the stator and the rotor.