Bow Spring Plate for Variable Displacement Pump Slide

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Solution Overview

Problem

Current variable displacement pumps in vehicle oil systems rely on compression springs, which increase weight, cost, and space requirements due to off-axis bending and non-linear deflection, leading to inconsistent output flow.

Innovation Solution

A variable displacement pump design utilizing a bow spring plate that contacts a slide to bias its rotation about an arc of curvature, with a dowel pin anchoring the bow spring plate, providing a more compact and linear force distribution, reducing the need for additional spring retainer components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a compression spring is used to bias the slide, then the pump can vary output flow rate, but the pump requires additional space envelope and increased weight for spring seating surfaces and alignment members

Engineering Contradiction:

Improvevariable output flow rateVSAvoidspace envelope

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent employs a bow spring with a curved, arc-shaped design that allows the spring to expand and contract within a compact space. The curved geometry enables the spring to provide the necessary biasing force while fitting within the existing pump housing without requiring additional space envelope or external seating surfaces.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The bow spring is positioned and oriented within the pump housing to utilize three-dimensional space efficiently. By anchoring the spring at strategic locations and allowing it to deflect in a specific direction, the design eliminates the need for additional alignment members and centering components that would increase the space envelope.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If a compression spring is used to bias the slide, then the pump can vary output flow rate, but the pump weight and cost increase due to reinforced seating surfaces and center alignment members

Engineering Contradiction:

Improvevariable output flow rateVSAvoidpump weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The bow spring's curved geometry is designed to naturally maintain alignment during deflection, eliminating the need for additional center alignment members. The spring's shape provides inherent stability and consistent force application without requiring reinforced seating surfaces or extra support components.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Adaptability or versatility

If a compression spring is used to bias the slide, then the pump can vary output flow rate, but the spring bends off-axis requiring center alignment members to maintain consistent spring force

Engineering Contradiction:

Improvevariable output flow rateVSAvoidcenter alignment member

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The bow spring is designed with a curved profile that guides its deflection path, ensuring it remains aligned with its neutral axis during operation. This geometric design prevents off-axis bending and eliminates the need for center alignment members, simplifying the overall device structure.

Inventive Principle:

Principle #14Spheroidality (Curvature)

4Adaptability or versatility

If a compression spring is used with 30% to 70% deflection, then the pump can vary output flow rate, but the non-linear deflection creates inconsistent pump output flow

Engineering Contradiction:

Improvevariable output flow rateVSAvoidconsistent pump output flow

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The bow spring is designed with specific geometric parameters including its curvature radius, thickness, and width to achieve a more linear force-deflection relationship. By carefully selecting these parameters, the spring provides consistent and predictable spring force over its operating range, resulting in more consistent pump output flow.

Inventive Principle:

Principle #35Parameter changes

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 bow spring plate design offers a more compact and cost-effective solution with predictable, linear spring force, reducing weight and maintaining consistent pump output across a range of deflections, unlike traditional coiled springs.

Implementation Method 1

A bow spring plate defining a biasing member directly contacts the slide to bias the slide to rotate about an arc of curvature within the pump body

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS11242852B2Variable displacement oil pump slide with bow spring

Publication Date: 2022.02.08 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

An automobile vehicle variable displacement pump includes a pump body having a pump shaft extending through the pump body. A rotor is connected to the pump shaft and co-rotates with the pump shaft. The rotor has multiple radially outwardly directed slots. A vane support ring supports multiple vanes, the vanes individually slidably received in one of the slots of the rotor. A slide is rotatably connected to the pump body having the rotor and the vane support ring positioned within an inner wall of the slide. A bow spring plate defining a biasing member directly contacts the slide to bias the slide to rotate about an arc of curvature.