Air Driven Hydraulic Pump With Elastic Bladder Isolation
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Solution Overview
Problem
Air motor driven hydraulic pumps face limitations in achieving efficient performance across varying pressures, lacking metered delivery and return capabilities, and often suffer from fluid contamination issues.
Innovation Solution
The design incorporates a pressure actuator valve for adjustable output flow, a zero-leak return valve for independent control of hydraulic fluid return, and an elastic bladder to isolate fluid from air exposure, allowing operation in any orientation and achieving high pressures with a hydraulically actuated air cut-off valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a reciprocating air motor is used to drive the hydraulic pump, then the pump can generate high hydraulic pressures (10,000 psi or more), but the performance is less than what could have been achieved with a more efficient machine, especially at high and low pressures
Solution Approach 1:
The patent employs a rotary air motor instead of a reciprocating one, providing continuous rotation for more efficient power transmission. The system includes variable flow control valves that allow dynamic adjustment of air supply to the motor, enabling the pump to maintain optimal performance across a wide range of pressures from low to high, resolving the efficiency problem at extreme pressure points
2Productivity
If a fixed relationship between hydraulic pressure and air pressure is used, then the pump operates continuously, but the flow rate cannot be adjusted and metered delivery is not achieved
Solution Approach 1:
The patent introduces variable flow control valves that dynamically adjust the air supply to the rotary air motor based on operational requirements. This enables the pump to provide metered delivery with adjustable flow rates while maintaining continuous operation capability, achieving both adaptability and productivity
Solution Approach 2:
The system changes the operating parameters by allowing variable adjustment of air pressure and flow rate to the rotary motor. This parameter flexibility enables the pump to deliver metered flow rates while maintaining continuous operation, resolving the contradiction between fixed continuous operation and adjustable flow rate
3Device complexity
If the pump is operated in fixed orientations, then the internal components are simplified, but the pump cannot be operated in any orientation and fluid contamination occurs
Solution Approach 1:
The patent employs an elastic bladder as a flexible membrane that separates the hydraulic fluid from the air motor components. This flexible barrier allows the pump to be operated in any orientation while preventing fluid contamination of the air motor, maintaining operational flexibility without requiring complex sealed connections in multiple directions
4Productivity
If compressed air is continuously supplied to the pump, then the pump operates continuously, but the air supply cannot be controlled to vary the flow rate
Solution Approach 1:
The patent incorporates variable flow control valves that dynamically adjust the compressed air supply to the rotary air motor. This enables continuous operation with controllable flow rate, allowing the operator to vary the flow rate according to requirements while maintaining continuous pump operation
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
This configuration provides a continuously variable and adjustable output flow rate, independent control of pressure and return flow, and prevents fluid contamination, enabling efficient operation across a wide range of pressures and orientations while maintaining high pressure capabilities.
Implementation Method 1
hydraulic fluid isolated from air exposure by an elastic bladder
Implementation Method 2
pressure actuator valve that varies the flow rate of air supplied to the air motor
Implementation Method 3
zero leak return valve that can be adjusted to continuously vary or completely turn off or on the return flow of hydraulic fluid
Implementation Method 4
hydraulically actuated air cut-off valve
Implementation Method 5
driven by a high speed rotary air motor through a gear reduction unit
Data Source
AI summary
A rotary air motor driven hydraulic pump has separate pressure and return actuators and first and second stage eccentric driven pistons 180 degrees out of phase and driven by the motor through a gear reduction unit. The pressure and return actuators are on/off/proportional valves and the pump has two pressure relief valves with one adjustable from outside of the pump for a user to set a pressure limit of the pump. Above a certain output pressure limit, a bypass valve shunts flow in excess of that needed to precharge the second stage compression chamber from the first stage piston to an elastic reservoir from which the hydraulic fluid pumped by the pump is drawn. To make the pump stall at a certain output pressure, a pressure limiting valve can be used that cuts off the air supply to the pump at the desired output pressure.