Arcuate Rotary Piston Actuator for Fast Wide-Angle Motion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary hydraulic actuators in heavy equipment applications face challenges in achieving high actuation speed, wide ranges of motion, efficiency in fluid power usage, and ease of maintenance, while also being compact and lightweight, with limited scalability to meet the power-to-weight ratios and field-serviceability requirements.
Innovation Solution
A rotary piston actuator assembly with an arcuate-shaped piston and bearing sleeve assembly, which includes a rotor assembly and a fluid delivery shaft, providing a compact and lightweight design that converts fluid pressure into rotary motion with improved torque and motion range, and features a friction-reducing coating for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If linear hydraulic actuators are used for heavy equipment applications, then power delivery is sufficient, but actuation speed is limited and ranges of motion are restricted
Solution Approach 1:
The patent replaces the traditional linear-to-rotary mechanical conversion mechanism with a direct rotary hydraulic actuation system. Pressurized fluid directly drives the rotor assembly to rotate, eliminating the need for external linear actuators and mechanical conversion joints, thereby achieving higher actuation speeds and wider ranges of motion while reducing mechanical complexity
Solution Approach 2:
The patent employs hydraulic pressure directly applied to the rotor assembly to generate rotational motion. The pressurized fluid acts on the rotor to produce torque and rotation, enabling high-speed actuation and wide motion ranges without the limitations of linear-to-rotary mechanical conversion
2Weight of moving object
If rotary hydraulic actuators are used for continuous inertial loading, then load holding is not required, but power-to-weight ratio and field-serviceability are insufficient
Solution Approach 1:
The rotor assembly is designed as a separable component that can be independently removed from the housing. This segmentation allows the rotor to be extracted through the open end of the housing for replacement or maintenance without disassembling the entire actuator, significantly improving field-serviceability while maintaining a compact and lightweight design
Solution Approach 2:
The rotor assembly is designed to be extractable from the housing through the open end. This extraction capability enables easy removal, replacement, and maintenance of the rotor component in field conditions, addressing the field-serviceability requirement while keeping the overall actuator design compact and lightweight
3Speed
If arcuate bearing sleeve assembly is added to reduce friction, then actuation speed increases, but device complexity increases
Solution Approach 1:
The bearing sleeve is integrated directly into the housing structure, forming a unified component rather than a separate assembly. This merging reduces the number of discrete parts and simplifies the overall device complexity while maintaining the friction-reducing functionality that enables high actuation speeds
Solution Approach 2:
The bearing sleeve is designed with an arcuate (curved) cross-section that matches the rotational path of the rotor. This curved geometry reduces friction by aligning the bearing surface with the rotor's motion, enabling high-speed actuation while the integration into the housing keeps the overall design simple
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 solution enables higher actuation speeds, wider ranges of motion, and more consistent torque delivery across the motion range, while being more resistant to contamination and easier to maintain, thus addressing the limitations of traditional linear-to-rotary mechanisms.
Implementation Method 1
pistons of the rotor are moved by fluid under pressure
Implementation Method 2
fluid under pressure... converts fluid pressure into rotary motion
Implementation Method 3
features a friction-reducing coating for enhanced performance
Data Source
AI summary
The subject matter of this specification can be embodied in, among other things, a rotary actuator that includes a housing defining an arcuate chamber comprising a cavity, a rotor arm configured for rotary movement, an arcuate-shaped first piston disposed in said housing for reciprocal movement in the arcuate chamber, where a seal, the cavity, and the piston define a pressure chamber that includes part or all of the arcuate chamber, and a portion of the piston contacts the rotor arm, and a rotor assembly rotatably surrounding said housing and having a rotary output tube about the axis, wherein the rotor arm extends radially outward to the rotary output tube and the rotor arm is coupled to the rotary output tube.