Driven caster wheel and assembly
A driven caster wheel assembly may include a wheel, an axle, a drive assembly, a drive shaft, and a bevel gear. The wheel may be mounted to the axle for rotation about a drive axis and steering about a substantially vertical steering axis. The drive shaft may extend along the steering axis from a first end to a second end, with the first end being connected to the axle and the second end being connected to the drive assembly such that the drive assembly controls rotation of the drive shaft about the steering axis. The bevel gear may connect the first end to the axle such that rotation of the drive shaft about the steering axis controls rotation of the wheel about the drive axis to drive the driven caster wheel assembly in a substantially horizontal direction. Various other assemblies and methods are also disclosed.
1. A driven caster wheel assembly, comprising:
a wheel mounted to an axle for rotation about a drive axis and steering about a substantially vertical steering axis;
a drive assembly;
a drive shaft extending along the steering axis from a first drive shaft end to a second drive shaft end, the first drive shaft end being connected to the axle and the second drive shaft end being connected to the drive assembly such that the drive assembly controls rotation of the drive shaft about the steering axis;
a bevel gear connecting the first drive shaft end to the axle such that rotation of the drive shaft about the steering axis controls rotation of the wheel about the drive axis to drive the driven caster wheel assembly in a substantially horizontal direction; and
a brake, disposed on the second drive shaft end, configured to retard motion of the drive shaft to thereby retard motion of the wheel, wherein the brake comprises a disc brake having:
a disc arranged on the second drive shaft end and configured to rotate about the steering axis along with the drive shaft; and
a pair of pads arranged on top and bottom sides of the disc, wherein the pads are compressible against the top and bottom sides of the disc to retard rotation of the disc and thereby retard rotation of the drive shaft.
2. The driven caster wheel assembly of claim 1 , wherein the drive axis and the steering axis together form an oblique angle such that the wheel is tilted relative to the drive shaft.
3. The driven caster wheel assembly of claim 1 , wherein the entire drive assembly is located above the wheel.
4. The driven caster wheel assembly of claim 1 , wherein the drive assembly comprises a drive motor and a drive belt controlled by the drive motor, the drive belt being wrapped around the second drive shaft end for rotating the drive shaft about the steering axis.
5. The driven caster wheel assembly of claim 1 , further comprising:
a steer assembly; and
a steer shaft extending along the steering axis from a first steer shaft end to a second steer shaft end, the first steer shaft end being connected to the axle and the second steer shaft end being connected to the steer assembly such that the steer assembly controls rotation of the steer shaft about the steering axis, which in turn steers the wheel about the steering axis.
6. The driven caster wheel assembly of claim 5 , wherein the drive shaft is concentrically arranged inside of the steer shaft.
7. The driven caster wheel assembly of claim 5 , wherein the steer assembly comprises a steer motor and a steer belt controlled by the steer motor, the steer belt being connected to the second steer shaft end for rotating the steer shaft about the steering axis.
8. The driven caster wheel assembly of claim 1 , wherein the wheel is configured to freely rotate 360 degrees about the steering axis.
9. The driven caster wheel assembly of claim 1 , wherein the bevel gear comprises a miter gear.
10. The driven caster wheel assembly of claim 1 , further comprising a chassis on which the drive assembly is mounted, wherein the chassis is located above the wheel, and the entire drive assembly is located on the chassis.
11. The driven caster wheel assembly of claim 1 , wherein the wheel is configured to roll along a surface.
12. The driven caster wheel assembly of claim 11 , wherein the bevel gear is configured such that the wheel is tilted relative to the steering axis so that the wheel is steerable about the steering axis at a single point of rotation.
13. The driven caster wheel assembly of claim 1 , wherein the wheel is configured to convert rotational movement into thrust to move the driven caster wheel assembly through water.
14. The driven caster wheel assembly of claim 1 , wherein the driven caster wheel assembly is mounted to a robot.
15. The driven caster wheel assembly of claim 14 , wherein the robot is configured to move through water.
16. The driven caster wheel assembly of claim 14 , wherein the brake is disposed distally from the wheel in a manner that protects the brake from environmental damage.
17. The driven caster wheel assembly of claim 1 , wherein the top and bottom sides of the disc extend in a horizontal plane that is substantially perpendicular to the steering axis.
18. The driven caster wheel assembly of claim 1 , wherein the wheel is tilted at an angle such that when the wheel is on a surface, the wheel rotates about the steering axis at a point that is a center of mass of the wheel.
19. The driven caster wheel assembly of claim 4 , wherein:
the drive assembly comprises a pulley coupled to the second drive shaft end; and
the drive belt is coupled to the second drive shaft end via the pulley.
20. The driven caster wheel assembly of claim 5 , wherein the steer shaft is mounted to the axle via a casting that is disposed around the bevel gear.