Adjustable diameter wheel assembly, and methods and vehicles using same

• US 20040000439A1
• Filed: 04/16/2003
• Published: 01/01/2004
• Est. Priority Date: 04/19/2002
• Status: Active Grant

• Current Assignee: Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: Papanikolopoulos, Nikolaos P., Burt, Ian T.
• Granted Patent: US 6,860,346 B2
• Time in Patent Office: Days
• US Class Current: 180/7.1
• CPC Class Codes: B60B 15/00 Wheels or wheel attachments designed for increasing traction vehicle tires B60C; non-skid devices temporarily attachable to resilient tires or resiliently-tired wheels B60C
• CPC Class Codes: B60B 19/04 expansible
• CPC Class Codes: B62D 57/00 Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels or endless track sledges B62B; motor sledges B62M
• CPC Class Codes: B62D 57/028 having wheels and mechanical legs B62D57/024 takes precedence; ground-engaging vehicle fittings for supporting, lifting or manoeuvring the vehicle, wholly or in part B60S9/00

Abstract

A powered wheel assembly, and method and ground-engaging vehicle (e.g., a robotic vehicle) using the same, are provided. The vehicle incorporates at least one of the wheel assemblies on its chassis body. In addition to its ability to propel the vehicle across a surface, the wheel assembly is reconfigurable between a retracted configuration, wherein the wheel assembly has a first rolling diameter, and an expanded configuration, wherein the wheel assembly has a second rolling diameter greater than the first rolling diameter. A drive motor assembly may both rotate the wheel assembly, e.g., propel the vehicle across a surface, and selectively actuate the wheel assembly from the first rolling diameter to the second rolling diameter, or to any intermediate rolling diameter.

Claims

1. A wheel assembly adjustable to provide a range of rolling diameters, the wheel assembly comprising:

a main shaft comprising an externally threaded portion;

a first hub and a second hub located on or adjacent the main shaft, wherein either the first hub or the second hub is threadably coupled to the threaded portion of the main shaft;

at least one reconfigurable wheel member coupled to both the first hub and the second hub, the wheel member having ground contact portions that define the rolling diameter of the wheel assembly;

a selectively engageable locking apparatus operable to restrict rotation of the main shaft relative to the first hub and the second hub.

2. The wheel assembly of claim 1, wherein the at least one reconfigurable wheel member comprises a plurality of links pivotally connected to the first hub and the second hub.

3. The wheel assembly of claim 2, wherein the ground contact portions comprise a portion of one or more of the plurality of links.

4. The wheel assembly of claim 1, wherein the at least one reconfigurable wheel member comprises an elastic membrane.

5. A wheel assembly with a selectively variable rolling diameter, the wheel assembly comprising:

a main shaft comprising an externally threaded portion;

a first hub and a second hub located on or adjacent the main shaft, wherein at least one of the first hub and the second hub is threadably coupled to the threaded portion of the main shaft;

a plurality of first links each pivotally coupled to the first hub; and

a plurality of second links each pivotally coupled to both the second hub and to one of the plurality of first links, wherein ground contact portions of two or more of the plurality of first links or two or more of the plurality of second links define the rolling diameter;

wherein movement along the main shaft of the first hub relative to the second hub results in radial displacement of the ground contact portions relative to an axis of the wheel assembly.

6. A powered wheel assembly operable to provide a selectable range of rolling diameters to a vehicle, the wheel assembly comprising:

a main shaft comprising an externally threaded portion;

a first hub positioned for rotation about an axis of the main shaft;

a second hub threadably engaged with the externally threaded portion of the main shaft;

a plurality of first links each pivotally coupled to the first hub; and

a plurality of second links each pivotally coupled to both the second hub and to one of the plurality of first links, wherein ground contact portions of either the plurality of first links or the plurality of second links define a rolling diameter of the wheel assembly.

7. The wheel assembly of claim 6, wherein relative movement of the second hub, along the axis of the main shaft, toward the first hub results in movement of the ground contact portions radially away from the main shaft.

8. The wheel assembly of claim 6, wherein relative movement of the second hub, along the axis of the main shaft, away from the first hub results in movement of the ground contact portions radially toward the main shaft.

9. The wheel assembly of claim 6, wherein one or both of the plurality of first links and the plurality of second links are substantially rigid.

10. The wheel assembly of claim 6, further comprising a locking apparatus operable to selectively stop or limit rotation of the main shaft relative to the vehicle.

11. The wheel assembly of claim 6, further comprising a driving apparatus coupled to the vehicle and operable to both rotate the wheel assembly and change the rolling diameter of the wheel assembly.

12. The wheel assembly of claim 11, wherein the driving apparatus, when the vehicle is in a first configuration, selectively rotates the first hub, the second hub, and the main shaft simultaneously about the axis of the main shaft to propel the vehicle, and, when the vehicle is in a second configuration, selectively rotates the first hub and the second hub relative to the main shaft to adjust the rolling diameter of the wheel assembly.

13. The wheel assembly of claim 6, wherein the main shaft is rotatable about an axle.

14. The wheel assembly of claim 13, wherein the axle is fixed.

15. The wheel assembly of claim 13, wherein the axle is powered.

16. The wheel assembly of claim 13, wherein the first hub is secured to the axle to prevent relative rotation therebetween.

17. The wheel assembly of claim 6, further comprising a sprocket coupled to the first hub.

18. The wheel assembly of claim 6, wherein the plurality of first links comprises eight first links and the plurality of second links comprises eight second links.

19. The wheel assembly of claim 6, wherein portions of the plurality of first links comprise the ground contact portions.

20. The wheel assembly of claim 6, further comprising a support member spanning between at least two ground contact portions.

21. A method of varying a rolling diameter of a powered wheel assembly for use with a ground-engaging vehicle, the method comprising:

providing a wheel assembly attached to the vehicle, the wheel assembly comprising;

a main shaft comprising an externally threaded portion;

a first hub positioned for rotation about an axis of the main shaft;

a second hub threadably engaged with the externally threaded portion of the main shaft;

a plurality of first links each pivotally coupled to the first hub; and

a plurality of second links each pivotally coupled to both the second hub and to one of the plurality of first links, wherein ground contact portions of either the plurality of first links or the plurality of second links define a rolling diameter of the wheel assembly;

selectively preventing relative rotation between the main shaft and the vehicle; and

rotating the first hub in a first direction, thereby causing the second hub to move along the threaded portion of the main shaft toward the first hub, thus repositioning the plurality of first links and the plurality of second links such that the ground contact portions move radially outward from the axis of the main shaft.

22. The method of claim 21, further comprising rotating the first hub in a second direction, thereby causing the second hub to move along the threaded portion of the main shaft away from the first hub, thus repositioning the plurality of first links and the plurality of second links such that the ground contact portions move radially inward toward the axis of the main shaft.

23. The method of claim 21, further comprising selectively allowing relative rotation between the main shaft and the vehicle, whereby subsequent rotation of the first hub in the first direction results in corresponding rotation of the second hub, the main shaft, the plurality of first link members, and the plurality of second link members.

24. A robotic vehicle having an adjustable ground clearance, the vehicle comprising:

a driving apparatus coupled to a body of the vehicle and operable to provide driving power to the vehicle;

at least one wheel assembly coupled to the body of the vehicle, the at least one wheel assembly comprising;

a main shaft comprising an externally threaded portion;

a first hub positioned for rotation about an axis of the main shaft;

a second hub threadably engaged with the externally threaded portion of the main shaft; and

at least one reconfigurable wheel member coupled to both the first hub the second hub, the wheel member having ground contact portions that define a rolling diameter of the at least one wheel assembly; and

a locking apparatus coupled to the body of the vehicle and operable to lock the main shaft relative to the body of the vehicle.

25. The vehicle of claim 24, wherein the at least one reconfigurable wheel member comprises:

a plurality of first links each pivotally coupled to the first hub; and

a plurality of second links each pivotally coupled to both the second hub and to one of the plurality of first links.

26. The vehicle of claim 24, wherein the at least one reconfigurable wheel member comprises an elastic membrane.