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US 11,255,416 B2Granted
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 (e.g., 6:1 or greater) 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.
Claims21
A linear actuator system comprising:
- an actuator chassis having a main drive axis;
- a first plurality of sheaves coupled respectively 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 spaced apart from one another by non-constant spacing, the sheaves in the first plurality of sheaves having different sheave diameters with respect to one another;
- 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 spaced apart from one another by non-constant spacing, the sheaves in the second plurality of sheaves having different sheave diameters with respect to one another,
- 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 positioned perpendicularly to the main drive axis and are offset with respect to one another by a static rotation angle about the main drive axis, and wherein points at respective ends of line segments extending along a geometric centerline of free spans from in the first plurality of sheaves and the second plurality of sheaves lie along a common circular profile orthogonal to the main drive axis.
2 more elements
A belt driven linear actuator system comprising:
- an actuator chassis;
- an actuation shaft movably coupled to the actuator chassis to translate along an axis;
- a first plurality of outer sheaves and a second plurality of outer sheaves coupled respectively to a first outer shaft and a second outer shaft, the first plurality of outer sheaves and the second plurality of outer sheaves configured to rotate freely about the first outer shaft and the second outer shaft, respectively, both fixed with respect to the actuator chassis;
- a first plurality of inner sheaves and a second plurality of inner sheaves coupled respectively to a first inner shaft and a second inner shaft, the first plurality of inner sheaves and the second plurality of inner sheaves configured to rotate freely about the first inner shaft and the second inner shaft, respectively, the first inner shaft and the second inner shaft configured to translate along the axis in the actuator chassis to drive the actuation shaft;
- and
- a flat belt extending from a first termination point, to and about:
- the first plurality of inner sheaves, the first plurality of outer sheaves, the second plurality of outer sheaves, the second plurality of inner sheaves, and to a second termination point,
- wherein the first outer shaft and the first inner shaft are tilted with respect to one another by a static rotation angle about the axis and where the second outer shaft and the second inner shaft are tilted with respect to one another by the static rotation angle about the axis so as to eliminate fleet angles.
5 more elements
A belt driven linear actuator system comprising:
- an actuator chassis;
- an actuation shaft movably coupled to the actuator chassis to translate along a main axis;
- a first plurality of sheaves having different diameters coupled to a first shaft and configured to rotate freely about the first shaft, the first shaft rotatably coupled to the actuator chassis and laterally fixed with respect to the actuator chassis;
- a second plurality of sheaves having different diameters coupled to a second shaft and configured to rotate freely about the second shaft, the second shaft configured to translate along the main axis in the actuator chassis to drive the actuation shaft;
- wherein the first shaft and the second shaft are tilted with respect to one another by a static rotation angle about the main axis so as to eliminate fleet angles;
- a flat belt extending from a first termination point, to and about the first plurality of sheaves, then to and about the second plurality of sheaves, extending to a traction sheave driven by a rotary actuator and finally extending to a take-up reel.
3 more elements
Dependencies are inferred from the claim text.