Variable Displacement Vane Pump Leakage Control
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Solution Overview
Problem
Conventional variable displacement vane pumps experience hydraulic fluid leakage due to axial clearance increases between the cam ring and housing components, leading to pressure loss and inefficiency in fluid supply for power steering applications.
Innovation Solution
The design incorporates a pump housing with a first and second housing, an adapter ring, a cam ring, and pressure plates with high-pressure introduction grooves positioned to minimize deformation and leakage, using a control section to manage internal pressures and eccentric movements of the cam ring, thereby reducing fluid leakage through optimized groove placement and pressure distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the second housing is tightened with the first housing by bolts, then the housing structure is secured, but the second housing deforms away from the cam ring, increasing axial clearance and causing hydraulic fluid leakage
Solution Approach 1:
The patent applies local quality by positioning high pressure introduction grooves at specific locations on the pressure plate and second housing that correspond to the cam ring's radial width region. This localized pressure introduction compensates for deformation at critical sealing areas, maintaining sealing reliability despite overall housing deformation. The grooves are strategically placed to ensure pressure acts where needed most to prevent leakage.
2Reliability
If the pressure plate is pressed to the cam ring by discharge pressure, then sealing is improved, but the pressure plate deforms toward the cam ring, increasing axial clearance on the outer circumferential side and causing leakage
Solution Approach 1:
The patent implements local quality by introducing high pressure at specific localized regions through grooves on both the pressure plate and second housing. These grooves are positioned within the radial width region of the cam ring to provide targeted pressure compensation. This localized pressure application maintains sealing effectiveness at critical interfaces while accounting for the pressure plate's deformation under load.
Solution Approach 2:
The patent applies preliminary anti-action by pre-positioning the high pressure introduction grooves to counteract the expected deformation of the pressure plate. The grooves are designed to introduce pressure in advance at locations where deformation will occur, creating a compensating effect that prevents excessive axial clearance and maintains sealing reliability before leakage can occur.
3Ease of operation
If high pressure is introduced to reduce sliding resistance, then cam ring movement is facilitated, but pressure leaks through increased axial clearance, reducing system efficiency
Solution Approach 1:
The patent applies local quality by positioning high pressure introduction grooves specifically within the radial width region of the cam ring. This localized pressure introduction achieves two objectives: it reduces sliding resistance at the cam ring interface to facilitate movement, and it maintains pressure containment by acting at the precise location where the cam ring contacts the housing, preventing leakage through axial clearance.
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 effectively suppresses hydraulic fluid leakage, maintaining pressure and efficiency in fluid supply by ensuring larger seal widths and appropriate pressure distribution, even with deformation of components, thus enhancing the performance of variable displacement vane pumps in power steering systems.
Implementation Method 1
a high pressure introduction groove arranged to receive the discharge pressure in the discharge port. The discharge pressure is introduced through the high pressure introduction groove to a portion between the cam ring and each of the both plate members, so as to decrease a sliding resistance at an eccentric movement of the cam ring
Implementation Method 2
a coil spring arranged to surround the valve element, and arranged to urge the valve element toward the plug
Implementation Method 3
a variable displacement vane pump which includes... a control valve arranged to control the discharge flow rate of the hydraulic fluid... a first fluid pressure chamber... a second fluid pressure chamber... a control section configured to control an internal pressure of the first fluid pressure chamber or the second fluid pressure chamber, and thereby to control the eccentric amount of the cam ring
Data Source
AI summary
A variable displacement vane pump includes: a plate side high pressure introduction groove formed in the pressure plate or in the cam ring, formed so that an entire is positioned within a radial width of the cam ring, and a part is positioned in a circumferential region between the suction port and the discharge port, and arranged to receive a hydraulic pressure larger than a suction pressure; and a housing side high pressure introduction groove formed in the second housing or in the cam ring, formed so that an entire is positioned within the radial width of the cam ring, that a radial center is positioned radially outside the radial center of the plate side high pressure introduction groove, and that a part is overlapped with the plate side high pressure introduction groove in the circumferential direction, and arranged to receive the hydraulic pressure larger than the suction pressure.