Vane Pump Control Spring Inclination for Constant Pressure
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Solution Overview
Problem
Variable displacement vane pumps in internal combustion engines often oversupply lubrication oil at higher operating speeds, leading to increased pressure and energy wastage, as the existing control spring mechanism fails to adequately reduce displacement to maintain constant output pressure beyond the maximum desired level.
Innovation Solution
The control spring is oriented at an angle relative to the control ring's pivot axis and contact point, reducing the moment arm and compression length, thereby maintaining a constant output pressure by offsetting the increase in spring force as the control ring moves from maximum to minimum displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the control spring is oriented perpendicular to the control ring pivot axis (conventional design), then the spring provides sufficient biasing force to move the control ring, but the spring force increases excessively as the control ring moves toward minimum displacement, preventing constant output pressure regulation
Solution Approach 1:
The patent changes the geometric parameter of the control spring orientation from perpendicular (conventional) to an acute angle (10-80 degrees) relative to the control ring pivot axis. This parameter change reduces the moment arm of the spring force, thereby reducing the increase in spring force as the control ring moves toward minimum displacement, enabling constant output pressure regulation in the regulated operating region.
2Stress or pressure
If the pump displacement is decreased to regulate output pressure at maximum desired level, then overpressure is prevented, but the spring force increase counteracts further displacement reduction, causing pressure to continue rising
Solution Approach 1:
By changing the control spring orientation parameter to an acute angle, the moment arm is reduced, which directly reduces the spring counteracting force that prevents adequate displacement reduction. This enables the feedback mechanism to effectively regulate output pressure to a substantially constant level in the regulated operating region.
3Stability of the object's composition
If the control spring moment arm is reduced by changing its orientation angle, then the spring force increase is offset and constant output pressure is achieved, but the spring geometry becomes more complex
Solution Approach 1:
The patent implements a relatively simple parameter change - orienting the control spring at an acute angle between 10-80 degrees to the pivot axis - rather than introducing complex mechanical mechanisms. This straightforward geometric modification achieves constant output pressure regulation without significantly increasing device complexity.
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 ensures a substantially constant output pressure in the regulated operating region, reducing energy wastage and preventing overpressure, leading to improved fuel efficiency and engine component protection.
Implementation Method 1
a control spring biasing the control ring towards the first position
Implementation Method 2
the longitudinal axis of the control spring being inclined at an angle of from about ten degrees to about eighty degrees with respect to a plane passing through the rotational axis about which the control ring pivots and the contact point between the control ring and the control spring
Data Source
AI summary
A variable displacement vane pump provides a substantially constant output pressure in its regulated operation region. A longitudinal axis of the control spring is inclined, with respect to a plane through the rotational axis of a pivot and a contact point between the control ring and the control spring. The inclination reduces the length of the moment arm between the spring and the pivot when the control ring of the pump is moved from the maximum displacement position to the minimum displacement position. The reduced length moment arm offsets the increase in the moment produced by compression of the control spring is offset to achieve a substantially constant output pressure. The control spring is compressed a reduced amount during pump operation to minimize the change in output force exerted by the control spring as the control ring moves between positions.