Single-Bushing Pneumatic Actuator for Compact Shaft Support

Solution Overview

Problem

Traditional slotted crank pneumatic actuators require two bushings for support, which increases the size and weight of the actuator assembly and limits its ability to fit within a smaller envelope.

Innovation Solution

A pneumatic actuator design that utilizes a single bushing with a length to diameter ratio greater than 1, positioned to support the actuator shaft without additional support points, allowing for actuation between defined positions while minimizing size and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two bushings are used to support the actuator shaft, then the actuator shaft is adequately supported, but the size and weight of the actuator assembly increases

Engineering Contradiction:

Improveactuator shaft supportVSAvoidactuator assembly weight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent merges the function of two separate bushings into a single bushing that supports the actuator shaft at one location. This consolidation reduces the number of parts, decreases weight, and simplifies the overall actuator assembly while maintaining adequate shaft support functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single bushing is designed to perform multiple functions: it supports the actuator shaft, provides a bearing surface for rotation, and maintains proper alignment. By making the single bushing multi-functional, the patent eliminates the need for a second bushing while ensuring reliable shaft support.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If two bushings are used to support the actuator shaft, then the actuator shaft is adequately supported, but the actuator assembly size increases

Engineering Contradiction:

Improveactuator shaft supportVSAvoidactuator assembly envelope

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the function of two separate bushings into a single bushing that supports the actuator shaft at one location. This consolidation reduces the number of parts, decreases weight, and simplifies the overall actuator assembly while maintaining adequate shaft support functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single bushing is designed to perform multiple functions: it supports the actuator shaft, provides a bearing surface for rotation, and maintains proper alignment. By making the single bushing multi-functional, the patent eliminates the need for a second bushing while ensuring reliable shaft support.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Weight of stationary object

If a single bushing is used to support the actuator shaft, then the actuator assembly size and weight are reduced, but the actuator shaft support capability must be maintained

Engineering Contradiction:

Improveactuator assembly weightVSAvoidactuator shaft support

Core Design Contradiction:

Weight of stationary objectVSReliability

Solution Approach 1:

The patent changes the parameters of the single bushing (such as increasing its length-to-diameter ratio to between 2 and 3, optimizing its material properties, and positioning it strategically) to compensate for the elimination of the second bushing. These parameter adjustments ensure that the single bushing can handle the support loads and maintain shaft reliability.

Inventive Principle:

Principle #35Parameter changes

4Area of stationary object

If a single bushing is used to support the actuator shaft, then the actuator assembly size and weight are reduced, but the actuator shaft support capability must be maintained

Engineering Contradiction:

Improveactuator assembly envelopeVSAvoidactuator shaft support

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The patent changes the parameters of the single bushing (such as increasing its length-to-diameter ratio to between 2 and 3, optimizing its material properties, and positioning it strategically) to compensate for the elimination of the second bushing. These parameter adjustments ensure that the single bushing can handle the support loads and maintain shaft reliability.

Inventive Principle:

Principle #35Parameter changes

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 single-bushing design enables the pneumatic actuator to achieve actuator shaft motion within set operating conditions, reducing the overall size and weight of the actuator assembly and allowing for a smaller envelope.

Implementation Method 1

A pneumatic actuator can include a housing and an actuator shaft disposed within the housing and configured to actuate between a first position and a second position. The actuator shaft can include a pneumatic cup at a first end

Methodology Applied

Scientific EffectPneumatic pressure: Pressure Increase

Implementation Method 2

The bushing can include a length to diameter ratio of greater than 1... μ1 is a first friction coefficient of the bushing, μ2 is a second friction coefficient of the bushing

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS12337951B2Single bushing supported pneumatic actuators

Publication Date: 2025.06.24 HAMILTON SUNDSTRAND CORP

AI summary

A pneumatic actuator can include a housing and an actuator shaft disposed within the housing and configured to actuate between a first position and a second position. The pneumatic actuator can include a single bushing located within the housing between the housing and the actuator shaft. The single bushing can be configured to support the actuator shaft without the actuator shaft being supported at a second location while allowing actuator motion under set operating conditions.