Gear Pump Dual Pressure Relief Ports

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Solution Overview

Problem

Existing gear pumps for compressor lubrication systems lack efficient pressure relief mechanisms, leading to potential leakage and reduced performance due to the reliance on spring-biased washers that may not effectively manage pressure fluctuations.

Innovation Solution

The design incorporates a torque ring with pressure relief ports that shift from a sealing to a non-sealing position when pressure exceeds the spring bias, allowing direct venting of oil through additional relief ports, thereby preventing leakage and maintaining efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single spring-biased washer is used for pressure relief, then the pump structure remains simple, but pressure relief effectiveness deteriorates under high pressure fluctuations

Engineering Contradiction:
Improvepressure relief effectivenessVSAvoidpressure relief mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The single pressure relief function is segmented into two separate mechanisms: a spring-biased washer for normal pressure relief and additional relief ports for high pressure relief. This segmentation allows each mechanism to specialize in specific pressure ranges, improving overall pressure relief effectiveness without requiring a completely complex new system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary structure (the torque ring with integrated relief ports) that mediates between the pump chamber and the pressure relief mechanisms. This intermediary provides a controlled pathway for fluid to bypass the main pumping elements and reach the relief mechanisms, enabling effective pressure management across different operating conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the pump is designed for specific compressor capacities, then pump performance is optimized, but versatility across different compressor types deteriorates

Engineering Contradiction:
Improvepump applicability across compressor capacitiesVSAvoidpump performance consistency
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The pump design incorporates multiple pressure relief mechanisms that can handle a wide range of pressure conditions, making the pump universally applicable across different compressor capacities. The dual pressure relief system (spring-biased washer plus additional relief ports) ensures the pump can maintain reliable performance whether operating at low pressure with smaller compressors or high pressure with larger compressors.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 pump's ability to manage pressure fluctuations, reducing leakage and enabling the use of a single pump size across different compressor capacities, improving performance and versatility.

Implementation Method 1

a spring biasing the pressure relief element toward the first condition from the second condition

Methodology Applied
Scientific EffectSpring bias: Spring

Implementation Method 2

If pressure in the pocket becomes sufficient to overcome the spring bias, the pressure will shift the washer out of sealing contact with the ends of the idler and rotor and open up a pathway for fluid to pass back through the cover inlet to relieve pressure

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP3186510B1Gear pump with dual pressure relief
Publication Date: 2018.12.26 CARRIER CORP
  • EP3186510B1 patent drawingFigure 1
  • EP3186510B1 patent drawingFigure 2
  • EP3186510B1 patent drawingFigure 3

AI summary

An internal gear pump (100) comprises: a rotor/torque ring comprising an internally lobed (140) rotor (130) and a torque ring (120) extending beyond at least a first end (134) of the rotor; an externally lobed (160) idler (150) encircled by the rotor; a hollow shaft (190) supporting the idler; a pressure relief element (200) positioned to shift between a first condition and a second condition; and a spring (210) biasing the pressure relief element toward the first condition from the second condition. The torque ring has at least one pressure relief port (240A, 240B) positioned so that: in the first condition, the pressure relief element blocks a path from an interior volume (235) of the pump to the pressure relief port; and in the second condition, relative to the first condition the pressure relief element does not block the path.