Elliptical Gear Pump Radial Vane Sealing Low Viscosity Slip
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Solution Overview
Problem
Conventional spur gear pumps are inefficient when handling low viscosity liquids due to internal slip and limited displacement volume, as the discharge pressure causes fluid to flow backwards past the gears, reducing output flow.
Innovation Solution
The design incorporates elliptical or oval gears with radially extending vanes and a housing chamber that minimizes radial clearance slip paths, using intermeshed gears and floating side plates to effectively seal and increase fluid volume displacement, enhancing the sealing of circumferential and lateral slip paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional spur gear pumps are used, then the structure is simple, but the efficiency is poor when handling low viscosity liquids due to internal slip and limited displacement volume
Solution Approach 1:
The patent employs elliptical gears instead of conventional circular spur gears. The elliptical shape creates asymmetric tooth spacing and engagement, allowing the gears to displace a larger volume of liquid per revolution while maintaining effective sealing. This asymmetric geometry reduces radial clearance slip paths and improves productivity for low viscosity liquids.
Solution Approach 2:
The patent introduces radial vanes that extend from the gear teeth outward to seal against the circular wall sections. This adds a radial sealing dimension to the traditional gear interface, creating multiple sealing surfaces (circumferential and radial) that prevent internal slip and improve fluid displacement efficiency.
2Stress or pressure
If discharge pressure is applied, then the pump can handle higher pressure liquids, but fluid flows backwards past the gears reducing output flow
Solution Approach 1:
The radial vanes are positioned to preemptively seal the radial clearance paths before discharge pressure can cause backward flow. By establishing sealing contact between the vanes and circular wall sections in advance, the system prevents the harmful effect of reverse flow through the gear clearance areas, maintaining output flow even at higher discharge pressures.
3Volume of moving object
If the gear diameter is increased to displace more liquid, then the displacement volume increases, but the number of teeth and gear complexity increases
Solution Approach 1:
The patent segments the sealing function across multiple components: the elliptical gear teeth provide circumferential sealing, while the radial vanes provide radial sealing. This segmentation allows each component to focus on a specific sealing function, achieving effective sealing and increased displacement volume without requiring an excessive number of teeth or increased gear 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 significantly increases the output flow of low viscosity liquids by reducing radial clearance slip and allowing a larger volume of liquid to be displaced per revolution, improving efficiency compared to traditional spur gear pumps.
Implementation Method 1
at least one of the teeth from each of the first and second gears includes a radially extending vane in sealing contact with the respective circular wall sections
Implementation Method 2
The gears are identical to each other with teeth located about their periphery and operatively positioned with the teeth of the gears intermeshed for all angular positions in a rotation of the gears
Implementation Method 3
A biasing member may be disposed within the vane slot and against the radially extending vane to urge the vane toward the respective generally circular wall section
Implementation Method 4
floating side plate members are laterally disposed about the gears to seal off liquid within the gear chamber
Data Source
AI summary
Elliptical or oval shaped gears of a positive displacement gear pump are disclosed. The gears have specially designed teeth at the ends of the gears' major and minor diameter axes. For example the teeth at the ends regions of the major diameter axes include radially extending wipers or vanes that extend and run against the circular gear case bore walls to seal liquid slip paths at radial running clearance areas between the tips of the gear teeth and the case bores. The pump may also have moveable wearplates on one or both sides of the gears that may be loaded laterally to seal liquid slip paths at lateral running clearance areas between the side faces of the gears and the pump faceplate and backplate.