Valveless Mechanical Pump for Dry-Sump Pressure Regulation
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Solution Overview
Problem
Existing scavenge pumps for dry-sump transmission lubrication face issues such as increased leakage risk with electric pumps and excessive pressure chamber build-up with mechanically driven pumps, which often require complex check valves.
Innovation Solution
A valveless, mechanical pressure regulating pump with a piston and spring mechanism that adjusts inlet port positions to regulate pressure without valves, using a cam for mechanical drive and incorporating a second spring to move the pump body when pressure exceeds a threshold, ensuring operation within a desired pressure range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electric pumps are used for scavenge pump applications, then pumping efficiency is improved, but leakage risk increases due to cables or connections passing through housing
Solution Approach 1:
The patent replaces electric pumps with a mechanically driven pump system that uses a cam mechanism and spring-loaded piston to achieve pumping action. This substitution eliminates the need for electrical cables or hydraulic connections passing through the housing, thereby resolving the leakage risk while maintaining pumping functionality through pure mechanical means
Solution Approach 2:
The pump body automatically adjusts its position relative to the cam based on internal pressure conditions. When pressure exceeds the spring pre-load, the pump body moves axially to reduce displacement and regulate pressure without external control systems, achieving self-regulation that improves reliability
2Stress or pressure
If mechanically driven pumps with check valves are used, then pressure control is improved, but device complexity increases due to additional valves and parts
Solution Approach 1:
The patent removes check valves and other complex pressure control components from the pump system. Instead, it uses the spring pre-load mechanism and axial movement of the pump body relative to the cam to inherently limit and regulate pressure, achieving pressure control through the basic pump architecture rather than additional valve assemblies
Solution Approach 2:
The pump body is designed to dynamically adjust its position axially relative to the cam based on pressure conditions. When pressure exceeds the spring pre-load, the pump body moves to reduce displacement, creating a dynamic pressure regulation system that adapts to operating conditions without requiring static valve components
3Reliability
If mechanically driven pumps are used to prevent leakage, then reliability is improved, but pressure chamber build-up occurs due to excessive pressure
Solution Approach 1:
The spring-loaded piston system provides inherent pressure feedback to the pump body position. When chamber pressure exceeds the spring pre-load, the force feedback causes the pump body to move axially, reducing displacement and thereby regulating pressure. This closed-loop feedback mechanism prevents excessive pressure build-up while maintaining the mechanical sealing benefits
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
The pump reduces design complexity by eliminating the need for valves, prevents pressure exceedance, and maintains efficient operation in dry-sump transmission lubrication systems, accommodating two-phase flow and self-priming without electrical connections.
Implementation Method 1
a second spring interposed between the casing and a bottom of the pump body, wherein the pump body is configured to move axially relative to the casing and compress the second spring when a pressure in the chamber exceeds a pre-load of the second spring
Data Source
AI summary
Systems and methods are disclosed for a valveless, mechanical, pressure regulating pump for use in transmissions and other mechanical systems. The pressure regulating pump may comprise: a casing; a pump body comprising an outer cylindrical portion and an inner cylindrical portion, wherein the outer cylindrical portion includes one or more inlet ports and the inner cylindrical portion includes one or more outlet ports; a piston interposed between the outer cylindrical portion and the inner cylindrical portion and configured to move axially, the piston and the inner cylindrical portion defining a chamber; a first spring at least partially interposed between the piston and the inner cylindrical portion; and a second spring interposed between the casing and the pump body, wherein the pump body is configured to move axially relative to the casing and compress the second spring when a pressure in the chamber exceeds a pre-load of the second spring.