Rear Hub Power Meter For A Bicycle

• US 20110120232A1
• Filed: 11/24/2009
• Published: 05/26/2011
• Est. Priority Date: 11/24/2009
• Status: Active Grant

• Current Assignee: SRAM LLC (SRAM International Corp.)
• Original Assignee: Saris Cycling Group Incorporated
• Inventors: Lassanske, Todd W.
• Granted Patent: US 8,336,400 B2
• Time in Patent Office: Days
• US Class Current: 73/862.29
• CPC Class Codes: B60B 27/0068 the element being a sensor
• CPC Class Codes: B60B 27/023 specially adapted for bicycles
• CPC Class Codes: B60B 27/047 comprising a freewheel mechanisms
• CPC Class Codes: B62J 45/411 Torque sensors
• CPC Class Codes: B62J 45/421 at the pedal crank
• CPC Class Codes: B62M 9/10 involving different-sized wheels, e.g. rear sprocket chain wheels selectively engaged by the chain, belt, or the like bicycle hubs rotatably arranged on axle B60B27/023
• CPC Class Codes: B62M 9/128 Accessories, e.g. protectors
• CPC Class Codes: G01L 3/1457 involving resistance strain gauges

Abstract

A power sensing arrangement for the rear hub of a bicycle. The power sensing arrangement includes a torque sensing assembly including torque sensing elements configured to measure a user applied torque. The torque sensing elements are in communication with an electronics assembly configured to process the measured data and transmit it to a receiver. The torque sensing elements are interconnected with the free hub assembly of the rear hub, and are operable to detect torque applied to the free hub from the rear cassette.

Claims

1. A drive hub assembly for a bicycle, comprising:

a drive gear arrangement; and

a freehub assembly including a freebody, wherein the drive gear arrangement is secured to the freehub assembly; and

a torque sensing arrangement for measuring torque applied to the drive gear arrangement, wherein the torque sensing arrangement is configured and arranged to sense torque transmitted from the drive gear arrangement to the freebody of the freehub assembly.

2. The drive hub assembly of claim 1, further comprising an electronics assembly in communication with the torque sensing arrangement, wherein the electronics assembly is adapted for receiving sensed torque data from the torque sensing arrangement, processing the torque data, and transmitting the processed torque data to a receiver.

3. The drive hub assembly of claim 2, wherein the drive gear arrangement defines a cavity positioned adjacent the freehub assembly, and wherein the electronics assembly is housed within the cavity.

4. The drive hub assembly of claim 3, wherein the electronics assembly is packaged into a rear disc mounted to an axially inner most portion of the freehub assembly.

5. The drive hub assembly of claim 1, wherein the torque sensing arrangement comprises at least one torque sensing element mounted to the freebody.

6. The drive hub assembly of claim 5, wherein the torque sensing element comprises at least one strain gauge secured to the freebody.

7. The drive hub assembly of claim 5, wherein the freebody comprises an outside member having a plurality of splines configured to couple the outside member to the drive gear arrangement, and wherein the outside member includes at least one recessed area for receiving the at least one strain gauge.

8. The drive hub assembly of claim 6, wherein the at least one strain gauge comprises a plurality of strain gauges circumferentially spaced from one another around an outside of the freebody.

9. The drive hub assembly of claim 6, wherein the at least one strain gauge is housed within the freebody.

10. The drive hub assembly of claim 9, wherein the at least one strain gauge comprises a plurality of strain gauges circumferentially disposed around an inner wall of the freebody.

11. The drive hub assembly of claim 10, wherein the plurality of strain gauges are spaced at 90 degrees from one another about a circumference of the freebody.

12. The drive hub assembly of claim 1, wherein the freebody comprises a two-piece construction having an inside member and an outside member, and wherein the torque sensing element is secured to the outside member of the freebody.

13. A power sensing drive assembly for use with a user-powered apparatus, comprising:

a gear arrangement;

a freehub assembly that is driven by the gear arrangement;

a torque sensing arrangement associated with the freehub assembly, wherein the torque sensing assembly is adapted to measure the torque applied by a user to the gear arrangement; and

an electronics assembly that receives sensed torque data from the torque sensing assembly.

14. The power sensing drive assembly of claim 13, wherein the gear arrangement defines an internal cavity, and wherein the electronics assembly is contained within the cavity.

15. The power drive sensing assembly of claim 13, wherein the freehub assembly includes a freebody, and wherein the torque sensing arrangement is secured to the freebody.

16. The power sensing drive assembly of claim 15, wherein the freebody includes an outside member, and wherein the torque sensing arrangement is secured to the outside member.

17. The power sensing drive assembly of claim 15, wherein the torque sensing arrangement is secured inside the freebody.

18. The power sensing drive assembly of claim 13, wherein the electronics assembly comprises a rear disc mounted at an axially innermost portion of the gear arrangement.

19. The power sensing drive assembly of claim 13, wherein the torque sensing arrangement comprises at least one torque sensing element.

20. The power sensing drive assembly of claim 19, wherein the at least one torque sensing element comprises a strain gauge.

21. The power sensing assembly of claim 19, wherein the at least one torque sensing element comprises a plurality of strain gauges circumferentially mounted about a portion of the freehub assembly.