Annular Pulley Layout for Dual-Action Linear Actuation
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Solution Overview
Problem
Conventional linear actuators lack the ability to operate in a dual action mode (both expand and contract) while maintaining a similar form factor to hydraulic actuators, and they do not efficiently regenerate electrical energy during both directions of actuator travel.
Innovation Solution
An annular pulley system is designed with a plurality of fixed and traveling sheaves arranged in annular configurations, where a flat belt with twists forms parallel and alignment spans to enable efficient dual action movement and energy regeneration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional linear actuators are designed to operate in dual action mode (expand and contract), then the ability to perform bidirectional movement is improved, but the form factor becomes larger and less compact compared to hydraulic actuators
Solution Approach 1:
The annular pulley system nests the traveling sheaves within the fixed sheaves in a concentric arrangement, with the output shaft passing through the center of the annular configuration. This nesting allows dual action operation while maintaining a compact form factor similar to hydraulic actuators.
Solution Approach 2:
The patent transitions from a linear arrangement to an annular (circular) configuration, utilizing radial symmetry and concentric circles. This dimensional change from linear to radial geometry enables dual action mode while maintaining compactness.
2Loss of energy
If conventional linear actuators are designed to regenerate electrical energy during actuator travel, then energy efficiency is improved, but the ability to regenerate energy in both directions of travel is limited
Solution Approach 1:
The annular pulley system with its symmetric configuration of fixed and traveling sheaves enables the same mechanical structure to perform energy regeneration in both expansion and contraction directions, providing universal bidirectional energy recovery capability.
Solution Approach 2:
The system alternates between expansion and contraction cycles, with the belt tension and sheave configuration enabling energy regeneration during each periodic cycle in both directions of travel.
3Length of moving object
If the annular pulley system uses parallel spans aligned with the axis of travel, then the travel range is maximized, but the belt tension generates torque on the output shaft
Solution Approach 1:
The patent introduces non-parallel spans with specific angular orientations to create asymmetric force distribution that counterbalances the torque generated by parallel spans, eliminating net torque on the output shaft while maintaining maximum travel range.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The annular pulley system allows for efficient dual action movement of a belt-driven linear actuator, maintaining a compact form factor, maximizing travel range, and enabling energy regeneration in both directions of travel, thus improving maintenance efficiency and energy utilization.
Implementation Method 1
A flat belt extends between and around the plurality of fixed sheaves and the plurality of traveling sheaves
Data Source
AI summary
In general, this disclosure involves a pulley system that includes a plurality of fixed sheaves arranged in a first annulus and a plurality of traveling sheaves arranged in a second annulus. The plurality of traveling sheaves are configured to travel along an axis of travel and are coupled to an output shaft configured to pass through the first annulus and translate along the axis of travel. The plurality of traveling sheaves are aligned with the plurality of fixed sheaves such that at least half of a plurality of spans between the plurality of traveling sheaves and the plurality of fixed sheaves are parallel spans that are parallel with the axis of travel. A flat belt extends between and around the plurality of fixed sheaves and the plurality of traveling sheaves, the flat belt including a plurality of twists along the parallel spans to form a plurality of twisted spans.