Helical drive actuator

Patent metadata

Field	Value
Publication number	US-10968993-B1
Application number	US-201816037324-A
Country	US
Kind code	B1
Filing date	Jul 17, 2018
Priority date	Jul 17, 2018
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

In one embodiment, an actuator has a roller, a helical track, and at least one track follower. The roller has a cylindrical body that has a first end, a second end that is offset from the first end along a central axis, and a cylindrical outer surface that extends from the first end to the second end. The helical track is disposed around the cylindrical outer surface in a helical pattern. The at least one track follower can be attached to a load, and rides along the helical track when the roller is rotated about the central axis so as to translate the load along an axial direction that is substantially parallel to the central axis. In some embodiments, the roller has an internal motor that is disposed within the cylindrical body.

First claim

What is claimed:

1. An actuator, comprising:
a roller having a cylindrical body that has a first end and a second end that are offset from one another along a central axis, and that has a cylindrical outer surface that extends from the first end to the second end;
a helical track disposed around the cylindrical outer surface in a helical pattern;
at least one track follower configured to be attached to a load and configured to ride along the helical track when the roller is rotated about the central axis so as to translate the load along an axial direction that is substantially parallel to the central axis;
at least one shaft having first and second shaft ends that extend outwardly from the first and second ends of the cylindrical body, respectively, along the central axis; and
an internal motor that is disposed within the cylindrical outer surface and that is configured to rotate the cylindrical outer surface relative to first and second shaft ends of the at least one shaft so as to rotate the cylindrical outer surface and helical track about the central axis.

2. The actuator of claim 1 , wherein the motor comprises a drive shaft, and the actuator comprises internal gearing that is connected between the drive shaft and the cylindrical outer surface such that the drive shaft is configured to drive the internal gearing and the internal gearing is configured to convert rotational motion of the drive shaft to rotational motion of the cylindrical outer surface.

3. The actuator of claim 2 , wherein the internal gearing comprises a planetary gear having a plurality of planet gears and a ring gear that engages the plurality of planet gears.

4. The actuator of claim 3 , wherein each planet gear has a different rotational axis that is radially spaced from the central axis, and the ring gear has a rotational axis that is aligned with the central axis.

5. The actuator of claim 4 , wherein the ring gear is rotationally fixed with respect to the cylindrical outer surface.

6. The actuator of claim 1 , wherein the helical track defines a helical path, and the helical track has at least one guide surface that is configured to guide the at least one track follower along the helical path around the actuator as the outer cylindrical surface is rotated about the central axis.

7. The actuator of claim 6 , wherein the at least one guide surface includes first and second guide surfaces that are opposite from one another, and the at least one track follower includes first and second track followers that are configured to ride along the first and second guide surfaces, respectively, as the outer cylindrical surface is rotated about the central axis.

8. The actuator of claim 6 , wherein each track follower comprises a track roller that is configured to roll along the at least one guide surface.

9. The actuator of claim 8 , wherein each track follower comprises a shaft configured to attach a respective one of the track rollers to the load, wherein the respective one of the track rollers is rotatably coupled to the shaft such that the track roller can rotate relative to the shaft.

10. The actuator of claim 1 , wherein the helical track has a pitch that is constant from the first end to the second end such that when the cylindrical outer surface is rotated at a constant rotational speed, the at least one track follower moves at a constant rate between the first and second ends along the axial direction.

11. The actuator of claim 1 , wherein the helical track has a pitch that varies between the first end and the second end such that when the cylindrical outer surface is rotated at a constant rotational speed, the at least one track follower moves at a varying rate between the first and second ends along the axial direction.

12. The actuator of claim 11 , wherein the pitch is smaller adjacent to at least one of the first and second ends than it is between the first and second ends such that a rate at which the at least one track follower travels along the axial direction decreases towards the at least one of the first and second ends.

13. A method of moving a load with an actuator, the method comprising:
causing an internal motor that is disposed within a cylindrical outer surface of a roller of the actuator to rotate the cylindrical outer surface about at least one shaft, such that the cylindrical outer surface rotates relative to first and second shaft ends of the at least one shaft that extend outward from a cylindrical body of the roller along a central axis, and to thereby cause a helical track disposed around the cylindrical outer surface to rotate in a first rotational direction with the cylindrical outer surface; and
causing at least one track follower of the actuator that is coupled to the load to ride along at least one guide surface of the helical track to thereby cause the load to translate linearly along a first axial direction that is substantially parallel to the central axis.

14. The method of claim 13 , wherein the rotating step comprises causing a motor of the actuator to rotate the cylindrical outer surface.

15. The method of claim 14 , wherein the rotating step comprises causing the motor to rotate the cylindrical outer surface at a constant speed, and the helical track has a variable pitch such that the causing step comprises causing the at least one track follower to move at different speeds along the first axial direction as the at least one track follower rides along the at least one guide surface.

16. The method of claim 14 , wherein the motor is an internal motor that is disposed within the cylindrical outer surface.

Assignees

• Amazon Tech Inc

Inventors

• Kalm William Scott

Classifications

• F16H25/2261 Primary

  arranged substantially perpendicular to the screw shaft axis · CPC title

• F16H25/2285

  with rings engaging the screw shaft with the inner perimeter, e.g. using inner rings of a ball bearing · CPC title

• F16H2025/228

  Screw mechanisms having rollers being supported by the screw shaft and engaging the nut · CPC title

• F16H2025/2081

  Parallel arrangement of drive motor to screw axis · CPC title