Variable Capacity Vane Pump With Opposite Control Chambers
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Solution Overview
Problem
Existing variable capacity lubricant vane pumps face challenges in maintaining constant lubricant pressure across varying internal combustion engine rotational speeds, as their chamber volume needs to adjust significantly to accommodate a tenfold change, and existing designs often suffer from pressure leakage and complex valve arrangements.
Innovation Solution
A mechanically driven lubricant vane pump with two control chambers positioned on opposite sides of the pivot axis, where one chamber acts against a preload spring and the other supports it, allowing for increased chamber size and reduced pressure leakage, utilizing a pivot bearing for sealing and a simple on/off or 3-way valve to control pressure levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If control chambers are arranged on the same side of the pivot axis, then the pump structure is compact, but the chamber size is limited and pressure leakage occurs
Solution Approach 1:
The patent transitions from arranging control chambers on the same side (2D planar arrangement) to opposite sides of the pivot axis (spatial distribution across different dimensions). This dimensional change allows each chamber to be positioned optimally, increasing their effective volume while using the pivot bearing as a natural seal to prevent pressure leakage between chambers.
Solution Approach 2:
The pivot bearing serves as an intermediary element that simultaneously functions as a mechanical support and a sealing barrier. By placing control chambers on opposite sides of the pivot axis, the bearing prevents direct fluid communication between chambers, eliminating pressure leakage without requiring additional sealing mechanisms.
2Reliability
If control chambers are arranged on opposite sides of the pivot axis, then pressure leakage is reduced and chamber size increases, but the pump structure becomes more complex
Solution Approach 1:
The pivot bearing is designed to serve multiple functions simultaneously: it acts as the rotational support for the control ring, provides sealing between the two control chambers, and serves as a structural anchor point. This multi-functionality reduces the need for additional separate components, thereby minimizing structural complexity despite the opposite-side arrangement.
3Stress or pressure
If pump chamber volume is variable to accommodate rotational speed changes, then constant lubricant pressure is maintained, but the mechanism becomes complex
Solution Approach 1:
The control ring is designed to pivot dynamically in response to varying engine rotational speeds. The two control chambers on opposite sides create不平衡 forces that automatically adjust the control ring position, thereby varying the pump chamber volume dynamically. This dynamic adjustment mechanism maintains constant lubricant pressure without requiring complex external control systems.
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 design allows for significant freedom in pump construction, reduces pressure leakage, and ensures consistent lubricant pressure across varying engine speeds, with a failsafe mechanism to prevent overpressure, enabling efficient lubrication of internal combustion engines.
Implementation Method 1
The pivot bearing in the pivot axis constitutes a sealing between the two control chambers
Implementation Method 2
The preload spring pushes the control ring in a high pump chamber volume direction
Data Source
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AI summary
A variable capacity lubricant vane pump (10;10') for lubrication of an internal combustion engine (12) is provided with radially slidable vanes (24) arranged in vane slits (22) of a rotor ring (20), the vanes (24) defining pump chambers (30) therebetween, a capacity control ring (26) surrounding the vanes (24) and being pivotable around a pivot axis (28) thereby varying the volume of the pump chambers (30), a first and a second hydraulic control chamber (36,38), both control chambers being in part defined by the control ring (26) and thereby pivoting the control ring (26), and a preload spring (34) preloading the control ring (26) in one direction, wherein the first control chamber (36) and the second control chamber (38) are arranged on different sides with respect to the pivot axis (28) and act against each other. This vane pump is very failsafe because, if the control valve (16) cannot be actuated, a high pump pressure at the pump outlet is set.