High reduction belt-driven linear actuator
AssigneeLiftwave, Inc.
InventorBlake Sessions
Life of this patent
Estimating the term…
Abstract
Disclosed herein are methods, systems, and components for the design of a flat belt based block and tackle design that is theoretically free of fleet angles. A mapping technique forms a set of planar positions for the centerlines of the free spans that provides a plurality of sheave geometries, which reside on a common axis and spans that are free of fleet angles at the sheave engagement interfaces. This permits the use of high-performing flat belts in high-reduction block and tackle topologies, with the principal benefits of an extended service life, high power transmission efficiency, more effective traction power transfer, and a compact machine design.
Claims14
A linear actuator system comprising:
- an actuator chassis having a main drive axis;
- a first plurality of sheaves coupled to a first shaft coupled to the actuator chassis, the first plurality of sheaves comprising sheaves having an axis of rotation that is coincident with the first shaft, the sheaves in the first plurality of sheaves comprising a pair of end sheaves and a middle sheave, wherein the middle sheave has a larger diameter than the pair of end sheaves, and wherein the middle sheave rotates independently of the pair of end sheaves;
- a second plurality of sheaves coupled respectively to a second shaft coupled to the actuator chassis, the second plurality of sheaves comprising sheaves having an axis of rotation that is coincident with the second shaft, the sheaves in the second plurality of sheaves comprising a pair of end sheaves and a middle sheave, wherein the middle sheave has a larger diameter than the pair of end sheaves, and wherein the middle sheave rotates independently of the pair of end sheaves;
- and
- a flat belt extended between the first plurality of sheaves and the second plurality of sheaves to form a plurality of spans,
- wherein at least one of the first shaft and the second shaft is configured to translate along the main drive axis, wherein the first shaft and the second shaft are oriented perpendicularly to the main drive axis and are offset with respect to one another by a rotation angle about the main drive axis, wherein the rotation angle is sufficient to eliminate fleet angles in the plurality of spans.
A method of driving a belt driven linear actuator system, the method comprising:
- energizing a rotary actuator connected to a redirection sheave to rotate the redirection sheave, the redirection sheave coupled to an actuator chassis, the actuator chassis comprising:
- a first plurality of sheaves coupled to a first shaft coupled to the actuator chassis, the first plurality of sheaves comprising sheaves having an axis of rotation that is coincident with the first shaft, the sheaves in the first plurality of sheaves comprising a pair of end sheaves and a middle sheave, wherein the middle sheave has a larger diameter than the pair of end sheaves, and wherein the middle sheave rotates independently of the pair of end sheaves;
- and
- a second plurality of sheaves coupled respectively to a second shaft coupled to the actuator chassis, the second plurality of sheaves comprising sheaves having an axis of rotation that is coincident with the second shaft, the sheaves in the second plurality of sheaves comprising a pair of end sheaves and a middle sheave, wherein the middle sheave has a larger diameter than the pair of end sheaves, and wherein the middle sheave rotates independently of the pair of end sheaves;
- and
- a flat belt extended between the first plurality of sheaves and the second plurality of sheaves to form a plurality of spans,
- wherein at least one of the first shaft and the second shaft is configured to translate along the main drive axis, wherein the first shaft and the second shaft are oriented perpendicularly to the main drive axis and are offset with respect to one another by a rotation angle about the main drive axis, wherein the rotation angle is sufficient to eliminate fleet angles in the plurality of spans.
Dependencies are inferred from the claim text.