Vane Pump Auxiliary Start Contour for Cold Start Reliability
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Solution Overview
Problem
Hydraulic vane cell pumps face issues with reduced conveying capacity and pressure build-up due to increased viscosity of lubrication oil at low temperatures, leading to short-circuits and unsatisfactory performance during cold starts and restarts, especially when dealing with highly viscous oil and air intake.
Innovation Solution
The introduction of an auxiliary start contour, arranged between the rotation axis and the inner peripheral face, which applies a part-stroke to radially displace conveying elements away from the rotation axis, allowing for mechanical initial movement without resilient loading, ensuring complete movement into pump portions and subsequent hydraulic operation by centrifugal force and pump pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conveying elements are radially displaced during rotation to convey fluid, then conveying capacity is improved, but during cold starts with high viscosity oil, the conveying elements fail to move completely into pump portions, causing short-circuits and reduced conveying capacity
Solution Approach 1:
The auxiliary start contour performs a preliminary radial displacement of the conveying elements before the main pump action begins. During cold starts, the auxiliary contour first moves the conveying elements radially outward to ensure they are properly positioned in the pump portions, preventing short-circuits. Once the pump is running, the auxiliary contour withdraws and the main conveying elements take over the full radial displacement function.
2Reliability
If resilient loading is used to urge conveying elements against the inner peripheral face, then conveying elements maintain contact for hydraulic operation, but wear and friction losses increase
Solution Approach 1:
The invention extracts the resilient loading mechanism from the system by using a purely mechanical auxiliary start contour instead. The auxiliary contour provides the necessary radial displacement during starting without relying on resilient elements, thereby eliminating the associated wear and friction losses while maintaining operational reliability through proper positioning of conveying elements.
3Device complexity
If the pump is designed for hydraulic operation only, then structural simplicity is maintained, but performance during cold starts with highly viscous oil is unsatisfactory
Solution Approach 1:
The auxiliary start contour is designed to be dynamically active only during starting conditions. It provides mechanical radial displacement when the pump is stationary or slow-running with high viscosity oil, ensuring proper positioning of conveying elements. Once the pump reaches operating speed and hydraulic conditions are established, the auxiliary contour automatically becomes inactive, allowing the system to operate in its simple hydraulic mode without the auxiliary mechanism interfering.
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 solution enhances the starting reliability and operational efficiency of hydraulic vane cell pumps by reducing wear, friction losses, and maintaining high conveying capacity under various operating conditions, including cold starts and restarts, without additional structural complexity or components.
Implementation Method 1
an auxiliary start contour, arranged between the rotation axis and the inner peripheral face, which applies a part-stroke to radially displace conveying elements away from the rotation axis
Implementation Method 2
which are urged against the inner peripheral face during a rotation of the rotor
Implementation Method 3
in order to forcibly redirect a part-stroke in the direction toward the inner peripheral face of the contour ring
Data Source
AI summary
A vane cell pump comprises a contour ring having an inner peripheral face and a rotatable rotor which has a plurality of conveying elements displaceable radially relative to a rotation axis. The inner peripheral face includes a plurality of pump portions each constructed with an intake region and a pressure region which are passed through by the conveying elements during rotation of the rotor. A narrow location at which the conveying elements are displaced radially inward toward the rotation axis to a greatest extent, is located between a pressure region and a subsequent intake region. By applying a part-stroke, an auxiliary start contour which is arranged between the rotation axis and the inner peripheral face radially inside the conveying elements in the region of at least one pump portion displaces the conveying elements to the greatest extent radially inwardly.