Variable Rate Oil Pump Eccentricity Control

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Solution Overview

Problem

Conventional variable-flow oil pumps used in powertrains are bulky due to mechanisms for adjusting oil flow, which limits their ability to efficiently adapt flow rates according to engine rotational speed and other driving parameters within a compact size.

Innovation Solution

A variable-flow oil pump design featuring a rotor with radially movable vanes and a mobile ring that pivots around an axis, allowing the circular chamber to change eccentricity relative to the rotor axis, with regulation chambers and elastic return mechanisms to control ring rotation, optimizing flow ratio within a reduced circular volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional mechanisms for moving the mobile ring (pusher and spring) are used to adjust oil flow, then the pump can adapt flow rate according to driving conditions, but the pump size increases significantly

Engineering Contradiction:
Improveflow rate adaptationVSAvoidpump size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent merges the mobile ring with the pump casing by making the ring form an integral part of the casing structure. The guide contours are formed directly on the casing inner surface, eliminating the need for separate pushers and springs that extend laterally beyond the ring. This integration reduces the overall pump volume while maintaining flow rate adaptation capability through the regulated movement of the mobile ring along the guide contours.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If a large stroke of the mobile ring is used to increase flow rate variation range, then the pump can offer extended flow rate ratios, but the pump size increases

Engineering Contradiction:
Improveflow rate variation rangeVSAvoidpump size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent changes the movement dimension of the mobile ring from lateral translation (perpendicular to the rotor axis) to rotation around an axis perpendicular to the rotor axis. This dimensional change allows the ring to achieve a large effective stroke for flow rate variation while the physical dimensions of the pump remain compact. The rotational movement enables the ring to sweep through a large angular range, creating significant variation in the admission and expulsion volumes without increasing the pump's external footprint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Shape

If the mobile ring is moved in translation to maintain a circular pump shape, then the pump size becomes substantially circular, but the total diameter is still much larger than the useful chamber volume

Engineering Contradiction:
Improvecircular pump shapeVSAvoidpump diameter
Core Design Contradiction:
ShapeVSVolume of moving object

Solution Approach 1:

The patent inverts the conventional approach by making the mobile ring rotate around an axis perpendicular to the rotor axis, rather than translating parallel to the rotor axis. This inversion allows the ring to maintain a compact circular footprint while achieving large flow rate variation through rotational movement. The ring's rotation around a peripheral axis enables the useful chamber volume to be much larger relative to the overall pump diameter, as the ring sweeps through a large angular range within the compact circular boundary.

Inventive Principle:
Principle #13The other way round (Inversion)

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 design enables extended variation of flow rate ratios between inlet and outlet while minimizing the pump's size, allowing for efficient oil flow adaptation and reduced wear, making it suitable for compact powertrain applications.

Implementation Method 1

A compression spring acts as an elastic return element in order to return the excrescence to its rest position.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3037664B1Variable rate oil pump
Publication Date: 2018.04.11 RENAULT SA
  • EP3037664B1 patent drawingFigure 1
  • EP3037664B1 patent drawingFigure 2

AI summary

The invention provides a variable-flow oil pump, particularly for use in motor vehicle engines. The pump comprises a pump housing (15), a movable ring (4), and a rotor (1) with radially movable vanes (5) configured to rotate within a circular chamber (2) that dictates the radial position of the vanes (5). The chamber (2) is defined within the movable ring (4), which is itself configured to pivot relative to the pump housing (15) about a ring rotation axis (Ω), thus modifying the eccentricity of the chamber (2) with respect to the rotor axis (X). The ring rotation axis (Ω) passes through the circular chamber (2).