Hydraulic Swash Block Positioning via Variable Container Volume
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Solution Overview
Problem
The existing hydraulic swash block positioning systems in variable displacement pumps suffer from significant oil flow losses due to oscillating swash block movements, leading to extreme oil pressure fluctuations and reduced hydraulic efficiency, as the system relies on constant flow restrictions to maintain average swash block position, which is inefficient and prone to cavitation.
Innovation Solution
The hydraulic swash block positioning system incorporates a variable container volume connected to the feeding line, with an adjuster that synchronizes with piston chamber changes, and includes a flow restriction to damp oscillations, ensuring stable oil pressure and minimizing losses by compensating volume changes and using counter-phase swash blocks to reduce oscillations and vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a flow restriction is used to maintain average swash block position, then the swash block position can be controlled, but extreme oil pressure fluctuations and energy losses occur
Solution Approach 1:
The patent applies dynamics by making the container volume variable instead of fixed. The container volume changes synchronously with the number of piston chambers connected to the high pressure source, allowing the system to adapt dynamically to oscillating conditions while maintaining stable average pressure and reducing energy losses through the flow restriction.
Solution Approach 2:
The patent changes the parameter of container volume from constant to variable. By adjusting the container volume synchronously with piston chamber connections, the system compensates for volume changes in the feeding line, stabilizing oil pressure and reducing the harmful effects of flow restrictions while maintaining position control.
2Stability of the object's composition
If the control valve opening is increased to prevent extreme low oil pressure, then oil pressure stability improves, but oil flow losses through the control valve increase
Solution Approach 1:
The patent applies preliminary action by pre-adjusting the container volume synchronously with piston chamber connections before pressure extremes can develop. This proactive volume compensation prevents the need for excessive control valve openings, maintaining pressure stability while minimizing high pressure oil losses through the control valve.
3Loss of energy
If flow restriction is reduced to minimize energy loss, then hydraulic efficiency improves, but oil pressure becomes insufficient to maintain swash block position
Solution Approach 1:
The patent creates a compensating volume change in the container that mirrors the volume changes in the feeding line caused by swash block oscillations. This copied volume variation synchronously compensates for pressure fluctuations, allowing smaller flow restrictions that reduce energy losses while maintaining sufficient oil pressure for position control.
Data Source
AI summary
A hydraulic swash block positioning system for positioning a swash block to set a variable displacement, the hydraulic device including a rotor with pistons and piston chambers, the positioning system having, between the housing and the swash block, a positioning cylinder with a positioning piston forming a positioning chamber for setting an average value of the swash block position and a control valve connecting the high oil pressure source with the positioning chamber through a feeding line. In accordance with the invention the feeding line is connected to an oil container that has a variable container volume that can be adjusted synchronously with the changes in the number of piston chambers connected to the high oil pressure source.