Torque sensor for a continuously variable transmission

• US 6,575,047 B2
• Filed: 09/02/2001
• Issued: 06/10/2003
• Est. Priority Date: 09/08/2000
• Status: Expired due to Fees

• Current Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: WK Lamellen und Kupplungsban Beteiligungs KG
• Inventors: Haas, Wolfgang, Reik, Wolfgang, Mair, Ulrich
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): Mack, Corey D.
• Application Number:
  US09/945,544
• Publication Number:
  US 20020056327A1
• Time in Patent Office: 646 Days
• Field of Search: 738/621.91, 738/623.1, 738/622.9, 738/623.21, 738/263.28, 738/620.8
• US Class Current: 73/862.191
• CPC Class Codes: F16H 55/56 of which the bearing parts are relatively axially adjustable
• CPC Class Codes: F16H 59/16 Dynamometric measurement of torque
• CPC Class Codes: F16H 61/66272 characterised by means for controlling the torque transmitting capability of the gearing

Abstract

A torque sensor for producing a torque-dependent pressing force. The sensor includes at least one input member and at least one output member. A power-transmitting element is arranged between the input and output members. The torque sensor can be utilized in a continuously variable transmission.

Claims

1. A continuously variable transmission, said transmission comprising:

a first set of coaxial conical disks adapted for relative axial movement to vary the axial spacing between the first set of disks;

a second set of conical disks adapted for relative axial movement to vary the axial spacing between the second set of disks, wherein the second set of disks is spaced from and opposite to the first set of disks so an axial space between the first set of disks is radially opposite from an axial space between the second set of disks;

a power transmission member positioned to engage and to pass between the first and second sets of disks to transmit torque therebetween; and

a torque sensor connected with at least one of the first and the second set of disks for sensing a torque level applied to the transmission and for generating a torque-dependent pressing force on a torque-transmitting member, said torque sensor including;

at least one torque-receiving input member and at least one torque output member;

a torque-transmitting member disposed between the at least one input member and the at least one output member, wherein the torque-transmitting member receives a pressing force from the input member to transmit power between the input and the output members, and

wherein the torque-transmitting member positioned between the input member and the output member is movable radially, relative to an axis of rotation about which the input and output members can rotate, to impart a pressing force to the output member when an input torque is applied to the input member.

2. A continuously variable transmission in accordance with claim 1, wherein the torque that is transmitted between the input member and the output member contains a power component acting in the circumferential direction and a power component acting in the axial direction, and wherein the power component acting in the circumferential direction is proportional to a power component acting in the circumferential direction of power that is transmitted between the power transmission member and at least one of the first and second set of disks, wherein the torque sensor is connected to that at least one set of disks.

3. A continuously variable transmission in accordance with claim 1, wherein at least one ramp is provided on each of the input member and the output member, which ramps support the torque-transmitting member during a power transmission process between those members.

4. A continuously variable transmission in accordance with claim 3, wherein during a pushing operation in which torque is applied to the input member, as well as during a pulling operation in which torque is applied to the output member, power is transmitted between the ramps by the torque-transmitting member, and the deviation of the pressing force generated in the torque sensor from the pressing force required for torque transmission between the disk sets is substantially identical during the pushing operation and the pulling operation.

5. A continuously variable transmission in accordance with claim 3, wherein at least one ramp, along which at least one torque-transmitting member is movable, is connected with one disk of a set of disks.

6. A continuously variable transmission in accordance with claim 5, wherein the one disk is a conical disk.

7. A continuously variable transmission in accordance with claim 3, wherein at least one ramp extends as a recess in a disk of a set of disks with which the torque sensor is connected.

8. A continuously variable transmission in accordance with claim 3, wherein the at least one ramp has a substantially constant slope relative to a radial plane passing through the torque sensor.

9. A continuously variable transmission in accordance with claim 3, wherein at least one torque-transmitting member is guided along at least one ramp during relative rotational movement between the input member and the output member of the torque sensor.

10. A continuously variable transmission in accordance with claim 3, wherein the input member and the output member each include at least one ramp that receives at least one torque-transmitting member therebetween and that a travel path of the torque-transmitting member during a relative rotational movement of the input and output members.

11. A continuously variable transmission in accordance with claim 3, wherein the at least one ramp has a curved shape in a radial plane.

12. A continuously variable transmission in accordance with claim 11, wherein the at least one ramp has a spiral shape in a radial plane.

13. A continuously variable transmission in accordance with claim 1, wherein the radial position of the torque-transmitting member is controlled as a function of the radial position of the power transmission member with respect to the disk set with which the torque sensor is connected.

14. A continuously variable transmission in accordance with claim 1, wherein the radial position of the torque-transmitting member corresponds substantially with the radial position of the power transmission member in relation to the first and second set of disks.

15. A continuously variable transmission in accordance with claim 1, wherein the radial position of the power transmission member relative to a set of disks is at substantially the same radial position as the torque-transmitting member for a torque sensor connected with that set of disks.

16. A continuously variable transmission in accordance with claim 1, wherein movement of the torque-transmitting member is guided in a predetermined manner.

17. A continuously variable transmission in accordance with claim 1, wherein radial movements of the power transmission member relative to a set of disks are coupled with radial movements of the torque-transmitting member of a torque sensor connected with that set of disks.

18. A continuously variable transmission in accordance with claim 1, wherein the radial position of the torque-transmitting member is dependent upon the transmission ratio of the transmission.

19. A continuously variable transmission in accordance with claim 1, including at least two torque-transmitting members, wherein the travel paths of the at least two torque-transmitting members are coupled with each other.

20. A continuously variable transmission in accordance with claim 19, wherein the two torque-transmitting members are carried in a retainer.

21. A continuously variable transmission in accordance with claim 20, wherein the retainer includes grooves along which the torque-transmitting members are movable.

22. A continuously variable transmission in accordance with claim 21, wherein at least one groove of the retainer extends in a substantially radial direction.

23. A continuously variable transmission in accordance with claim 1, wherein the torque output member is integrally formed with a disk of a set of disks with which the torque sensor is connected.

24. A continuously variable transmission in accordance with claim 1, wherein a circumferentially directed power component of power transmitted between the input member and the output member of the torque sensor corresponds substantially with a circumferentially-directed power component of power transmitted between a disk set connected with the torque sensor and the power transmission member.

25. A continuously variable transmission in accordance with claim 1, wherein each set of disks is connected with a separate torque sensor.

26. A method for controlling a torque sensor carried by a continuously variable transmission, said method comprising the steps of:

generating a signal indicative that the transmission ratio of the continuously variable transmission is to be changed;

changing the transmission ratio of the continuously variable transmission by changing axial distances between pairs of axially-movable conical disks, between each of which an endless, torque-transmitting means passes to transmit torque between the pairs of disks to shift the radial position of the torque-transmitting means within each pair of disks; and

providing a torque sensor having an axis of rotation and at least one power transmitting element between an input member of the torque sensor carried by the continuously variable transmission and an output member of the torque sensor, wherein the power transmitting element is movable radially relative to the torque sensor axis for transmitting torque between the torque sensor input and output members.