Gearbox torque measurement system

• US 10,473,554 B2
• Filed: 02/02/2016
• Issued: 11/12/2019
• Est. Priority Date: 02/02/2016
• Status: Active Grant

• Current Assignee: Moog Incorporated
• Original Assignee: Moog Incorporated
• Inventors: Larson, Lowell Van Lund, Deake, Jeremy Jason
• Primary Examiner(s): Patel, Harshad R
• Assistant Examiner(s): Tran, Tran M.
• Application Number:
  US15/013,234
• Publication Number:
  US 20170219445A1
• Time in Patent Office: 1,379 Days
• CPC Class Codes: B60K 17/16 of differential gearing
• CPC Class Codes: B60K 6/00 Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units arrangement or mounting in vehicles of electrical gearing, in which an electrical machine serves only as reduction gearing and not as the prime mover and in which no electrical storing means are used B60K17/12; control and regulation of purely electrical prime movers B60L; prime-movers comprising electrical and internal combustion motors in a common engine block or housing per se F02B65/00; electric motors or motor-generators used for starting the combustion engine F02N11/04; electric motors for synchronising gearing F16H3/12 Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00
• CPC Class Codes: F16H 2048/207 using torque sensors
• CPC Class Codes: F16H 48/00 Differential gearings cooling or lubricating of differential gearing F16H57/04
• CPC Class Codes: G01L 3/04 wherein the torque-transmitting element comprises a torsionally-flexible shaft
• CPC Class Codes: G01L 3/1478 involving hinged levers
• CPC Class Codes: G01L 5/0042 applying a torque
• CPC Class Codes: G01M 13/021 Gearings

Abstract

A torque transmission apparatus incorporates a differential gear system and a stationary sensor connected to the differential gear system for measuring output torque. The stationary sensor may be connected to a measurement output element of the differential gear system by a torsionally compliant measurement member, wherein the stationary sensor measures torsional deformation of the measurement member. The torsional deformation may be measured directly, or it may be measured following amplification by a gear train. A rotary position sensor may be used as the stationary sensor. Alternatively, the stationary sensor may be connected to the measurement output element of the differential gear system by way of a rigid measurement member, wherein the stationary sensor measures force applied by the measurement member. In this alternative, a force sensor may be used as the stationary sensor.

Claims

1. A gearbox system for connection to a motor (24), the gearbox system comprising:

a structural ground (G) to which the motor (24) is fixedly attached;

a differential gear system (12) including an input element (14), a transmission output element (16), and a measurement output element (18), wherein the transmission output element (16) rotates in response to rotation of the input element (14) and the measurement output element (18) reacts an output torque transmitted by the transmission output element (16) by providing a reaction torque equal and opposite to the output torque;

a rotatable input shaft (20) driven to rotate by the motor (24) and connected to the input element (14), wherein the input element (14) rotates in response to rotation of the input shaft (20);

a rotatable output shaft (22) driven to rotate by rotation of the transmission output element (16), wherein the rotatable output shaft (22) transmits the output torque;

a measurement member (26) connected to and arranged between the measurement output element (18) and the structural ground (G); and

a stationary sensor (30, 30′

) associated with the measurement member (26) or the measurement output element (18) for measuring at least one of (i) a deformation of the measurement member (26), (ii) an angular displacement of the measurement output element (18), (iii) a force applied by the measurement member (26), and (iv) a force applied by the measurement output element (18), the measurement by the stationary sensor (30, 30′

) being proportional to the output torque, wherein the stationary sensor (30, 30′

) generates a signal representative of the output torque.

2. The gearbox system according to claim 1, wherein the measurement member (26) is a torsionally compliant member arranged to undergo torsional deformation due to angular displacement of the measurement output element (18).

3. The gearbox system according to claim 2, wherein the stationary sensor (30, 30′

) measures the torsional deformation of the measurement member (26).

4. The gearbox system according to claim 2, wherein the stationary sensor (30, 30′

) measures the angular displacement of the measurement output element (18).

5. The gearbox system according to claim 4, further comprising a measurement gear train (34) associated with the measurement output element (18), wherein the measurement gear train includes an output gear (34B) driven to rotate through an angular displacement proportional to the angular displacement of the measurement output element (18), wherein the stationary sensor (30) is arranged to detect the angular displacement of the output gear (34B).

6. The gearbox system according to claim 5, wherein the stationary sensor (30) includes a rotary position encoder.

7. The gearbox system according to claim 5, wherein the stationary sensor (30) includes a resolver.

8. The gearbox system according to claim 5, wherein the measurement gear train (34) amplifies the angular displacement of the measurement output element (18).

9. The gearbox system according to claim 5, wherein the measurement gear train (34) includes at least one spring (36) arranged to remove backlash in the measurement gear train (34).

10. The gearbox system according to claim 5, wherein the measurement gear train (34) includes a pair of output gears (34B) arranged opposite one another to remove backlash in the measurement gear train (34).

11. The gearbox system according to claim 2, wherein the measurement member (26) includes at least one radially projecting end stop for engaging a pair of limit surfaces (11) associated with structural ground (G) for limiting a range of torsional deformation of the measurement member (26).

12. The gearbox system according to claim 1, wherein the measurement member (26) is a rigid member arranged to transmit torque from the measurement output element (18).

13. The gearbox system according to claim 12, wherein the stationary sensor (30, 30′

) includes a force sensor arranged to detect force applied to the stationary sensor (30, 30′

) by the measurement member (26).

14. The gearbox system according to claim 13, wherein the measurement member (26) includes a pivotally-mounted bell crank (26) having a first arm (26C) engaged by the measurement output element (18) and a second arm (26D) arranged to apply force to the stationary sensor (30, 30′

).

15. The gearbox system according to claim 1, wherein the differential gear system (12) includes a planetary gear system having a sun gear (12A), a ring gear (12B) surrounding the sun gear (12A), and at least one planet gear (12C) meshed with the sun gear (12A) and the ring gear (12B).

16. The gearbox system according to claim 15, wherein the input element (14) includes the sun gear (12A), the transmission output element (16) includes the at least one planet gear (12C), and the measurement output element (18) includes the ring gear (12B).

17. The gearbox system according to claim 1, wherein the gearbox system is adapted for connection to a second motor (24), wherein the differential gear system (12) further includes a second input element (14), and the gearbox system further comprises a second rotatable input shaft (20) driven to rotate by the second motor (24) and connected to the second input element (14) to drive rotation of the second input element.

18. The gearbox system according to claim 17, wherein the differential gear system (12) includes a planetary gear system having a pair of coaxial sun gears (12A), a pair of coaxial ring gears (12B) respectively surrounding the pair of coaxial sun gears (12A), and at least one planet gear (12C) meshed with the pair of sun gears (12A) and the pair of ring gears (12B), wherein the input element (14) and the second input element (14) include the pair of sun gears (12A), and the transmission output element (16) and the measurement output element (18) include the pair of ring gears (12B).

19. The gearbox system according to claim 18, wherein the transmission output element (16) indirectly engages the measurement output element (18) by way of the at least one planet gear (12C).

20. The gearbox system according to claim 1, wherein the measurement output element (18) includes at least one radially projecting end stop for engaging a pair of limit surfaces (11) associated with structural ground (G) for limiting a range of angular displacement of the measurement output element (18).

21. The gearbox system according to claim 1, wherein the transmission output element (16) directly engages the measurement output element (18).

22. A gearbox for connection to a motor (24) by way of a rotatable input shaft (20) driven to rotate by the motor (24), the gearbox comprising:

a structural ground (G) to which the motor (24) is fixedly attached;

a differential gear system (12) including an input element (14) which rotates in response to rotation of the input shaft (20), a transmission output element (16), and a measurement output element (18), wherein the transmission output element (16) rotates in response to rotation of the input element (14) and the measurement output element (18) reacts an output torque transmitted by the transmission output element (16) by providing a reaction torque equal and opposite to the output torque;

a measurement member (26) connected to and arranged between the measurement output element (18) and the structural ground (G); and

a stationary sensor (30, 30′

) associated with the measurement member (26) or the measurement output element (18) for measuring at least one of (i) a deformation of the measurement member (26), (ii) an angular displacement of the measurement output element (18), (iii) a force applied by the measurement member (26), and (iv) a force applied by the measurement output element (18), the measurement by the stationary sensor (30, 30′

) being proportional to the output torque, wherein the stationary sensor (30, 30′

) generates a signal representative of the output torque.