Fluid Pump for Linear Actuator with Regenerative Shuttle Valves

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Solution Overview

Problem

Conventional fluid pumps for linear actuators are inefficient, complex, and require a large number of components, leading to increased power consumption and size, while also being orientation-dependent due to gravity effects on fluid levels.

Innovation Solution

A fluid pump design with a housing having an inlet port and two outlet ports, a driven pump element, and control mechanisms for efficient fluid flow, including shuttles and check valves, allowing fluid to be regenerated between sides of the piston without routing through a reservoir, reducing pressure requirements and component count, and enabling operation in various orientations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional fluid pumps route fluid through a reservoir, then fluid flow control is simplified, but fluid flow path length increases and operating efficiency decreases

Engineering Contradiction:
Improveoperating efficiencyVSAvoidfluid flow path length
Core Design Contradiction:
ProductivityVSLength of stationary object

Solution Approach 1:

The invention extracts and eliminates the reservoir from the fluid circulation path by implementing direct fluid regeneration from the second fluid chamber back to the first fluid chamber through the pump element. This removes the unnecessary detour through the reservoir, shortening the fluid flow path and improving operating efficiency while maintaining proper fluid level control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the fluid regeneration function directly into the pump housing by creating a direct fluid communication path between the second and first fluid chambers. This integration eliminates separate reservoir components and combines the return fluid path with the pump structure, reducing overall system complexity and improving efficiency.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If conventional fluid pumps use multiple valves to control fluid flow, then fluid flow control is achieved, but device complexity and component count increase

Engineering Contradiction:
Improvefluid flow controlVSAvoidcomponent count
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The pump element is designed to perform multiple functions: it actively pumps fluid from the first to second fluid chamber during extension, and passively receives regenerated fluid from the second to first fluid chamber during retraction. This multi-functionality eliminates the need for separate valves to control bidirectional fluid flow, reducing component count while maintaining flow control capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses the natural pressure differential created during actuator operation to drive fluid regeneration automatically. During retraction, pressure in the second chamber naturally forces fluid back through the pump element to the first chamber without requiring active valve control or additional energy input, making the system self-regulating.

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If conventional fluid pumps require high pressure to open return valves, then fluid can be directed back to reservoir, but power consumption increases

Engineering Contradiction:
Improvefluid flow direction controlVSAvoidpower consumption
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The invention converts the normally wasted high-pressure fluid returning to the reservoir into a useful resource by directing it back to the first fluid chamber. The high-pressure fluid from the second chamber during retraction is captured and reused to supplement the first chamber, turning what would be energy waste into a performance benefit that reduces overall power consumption.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Instead of discarding fluid back to the reservoir, the system recovers and regenerates fluid by capturing the return flow from the second fluid chamber and redirecting it to the first fluid chamber through the pump element. This recovery process eliminates the energy waste associated with pumping fluid to and from the reservoir.

Inventive Principle:
Principle #34Discarding and recovering

4Reliability

If conventional fluid pumps and actuators are oriented in specific ways, then gravity effects on fluid levels are managed, but flexibility of use is reduced

Engineering Contradiction:
Improvefluid level managementVSAvoidorientation flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention uses a sealed hydraulic system with trapped air pockets in the second fluid chamber to compensate for fluid volume changes and maintain proper fluid levels regardless of orientation. The sealed design prevents fluid leakage and the compressible air acts as a buffer to maintain pressure and fluid distribution in any orientation, enabling flexible installation positions.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 improved fluid pump is more efficient, reduces power consumption, minimizes component count and size, and functions independently of orientation, enhancing the overall performance and flexibility of linear actuators.

Implementation Method 1

a driven pump element disposed within the housing... Rotation of the driven pump element in a first rotational direction results in fluid flow between the inlet port and the driven pump element along a first fluid flow path

Methodology Applied
Scientific EffectMechanical displacement: Pump

Implementation Method 2

a first check valve disposed on a second axial side of the driven pump element and movable between a closed position and an open position permitting fluid flow between the driven pump element and the first outlet port

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP3071835B1Fluid pump for a linear actuator
Publication Date: 2020.05.20 WARNER ELECTRIC TECHNOLOGY LLC
  • EP3071835B1 patent drawingFigure 1
  • EP3071835B1 patent drawingFigure 2
  • EP3071835B1 patent drawingFigure 3~4

AI summary

A fluid pump for a linear actuator, the linear actuator comprising a rod that extends or retracts by controlling the flow of fluid to and from portions of a fluid chamber on either side of a piston disposed within the fluid chamber and supporting the rod. The pump is of the rotary type and reversible and includes a valve structure comprising a first and second check valve (98,100) and a first and second shuttle (92,102) that enables the pump to redistribute fluid obtained from one portion of the fluid chamber on one side of the piston to the other portion of the fluid chamber on the other side of the piston without first returning the fluid to a fluid reservoir thereby increasing the efficiency of the pump.