Hydraulic Shut-Off Valve for Case Drain Pressure Equalization
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Solution Overview
Problem
Hydraulic motor systems face pressure spikes and imbalances due to spring-based mechanisms, leading to piston shoe lift and potential damage, which existing case drain lines are unable to prevent effectively.
Innovation Solution
A valve system with a spool mechanism that equalizes pressures across the hydraulic motor by routing fluid flow paths to connect the case drain line with control lines and return lines, ensuring PCD=PR'=PS'=PR, thereby preventing piston shoe lift and damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a spring-based mechanism is used to keep pistons in contact with the plate, then the motor structure is simplified, but pressure spikes and pressure imbalances occur causing piston shoe lift
Solution Approach 1:
A case drain pressure relief valve is introduced as an intermediary component to regulate and equalize pressure between the case drain line and control lines. This mediator prevents pressure spikes from reaching the piston shoes, eliminating the harmful effect of pressure imbalance while preserving the simple spring-based piston retention mechanism.
2Stress or pressure
If case drain lines are used to relieve excess pressure, then pressure relief is provided, but trapped return pressure in control lines causes pressure spikes upon shut-off valve closing
Solution Approach 1:
The case drain pressure relief valve acts as a pressure equalizing intermediary between the case drain line and control lines. By providing a controlled pressure relief path, it prevents trapped return pressure in control lines from causing dangerous pressure spikes when shut-off valves close, while maintaining effective case drain pressure relief.
3Productivity
If shut-off valves are closed to stop hydraulic fluid flow, then motor operation is stopped, but pressure spikes occur in control lines causing piston shoe lift
Solution Approach 1:
The case drain pressure relief valve is pre-configured to equalize pressures in control lines before shut-off valve closure occurs. This preliminary pressure equalization action prevents the formation of pressure spikes that would otherwise cause piston shoe lift during motor shutdown, ensuring reliable operation control without harmful pressure imbalances.
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 valve system effectively prevents case drain overpressure and pressure imbalances, keeping piston shoes in contact with the plate, reducing the likelihood of motor damage and enhancing the reliability and robustness of compact hydraulic motors.
Implementation Method 1
a spool within the sleeve and arranged for linear motion along a first axis... when the spool is in the second position, the fifth fluid flow port is in fluid communication with the second, third and fourth fluid flow ports
Data Source
AI summary
A valve for controlling the flow of hydraulic fluid to a hydraulic motor. The valve includes a sleeve and a spool. The sleeve includes a first fluid flow port for receiving hydraulic fluid from the supply line; a second fluid flow port for supplying hydraulic fluid to a second valve; a third fluid flow port for receiving hydraulic fluid from a first control line; a fourth fluid flow port for receiving hydraulic fluid from a second control line; and a fifth fluid flow port in fluid communication with the return line. The valve is arranged to be actuated to move the spool between a first position and a second position. When the spool is in the second position, the fifth fluid flow port is in fluid communication with the second, third and fourth fluid flow ports and the first fluid flow port is closed by the spool.