Variable Displacement Vane Pump Thermo-Compensation

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Solution Overview

Problem

Existing variable displacement vane pumps lack efficient control mechanisms to adjust displacement and pressure levels based on temperature and load conditions, leading to unnecessary high pressure and displacement at low engine speeds and temperatures.

Innovation Solution

A variable displacement vane pump design incorporating a thermally adjustable control valve and a control slide that adjusts displacement by controlling fluid communication and venting between control chambers, using temperature to switch between pressurization and venting modes to optimize lubricant delivery based on engine conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single control chamber is used to move lubricant, then the device complexity is reduced, but the ability to control displacement and pressure levels based on temperature and load conditions deteriorates

Engineering Contradiction:
Improvecontrol chamber structureVSAvoidtemperature and load condition control
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The control system is divided into two separate control chambers: a first control chamber for controlling pump displacement and a second control chamber for controlling pressure levels. This segmentation allows independent control of displacement and pressure, enabling the system to adapt to different temperature and load conditions without increasing overall structural complexity.

Inventive Principle:
Principle #1Segmentation

2Reliability

If high pressure and displacement are maintained at low engine speeds and temperatures, then lubricant delivery capability is ensured, but energy consumption increases and engine efficiency deteriorates

Engineering Contradiction:
Improvelubricant delivery capabilityVSAvoidpump energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The pump system dynamically adjusts displacement and pressure levels based on real-time engine operating conditions through the two control chambers. At low engine speeds and temperatures, the system maintains adequate lubricant delivery while reducing pressure and displacement to minimize energy consumption, thereby improving engine efficiency without compromising reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system changes operating parameters (displacement volume and pressure levels) based on engine speed and temperature conditions. By varying these parameters dynamically, the system optimizes the balance between lubricant delivery capability and energy consumption, preventing unnecessary high pressure and displacement at low operating conditions.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If a thermally adjustable control valve and dual control chamber system is implemented, then temperature-based control capability is improved, but device complexity increases

Engineering Contradiction:
Improvetemperature-based controlVSAvoidvalve and chamber structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The thermally adjustable control valve serves multiple functions: it controls fluid communication between the two control chambers, responds to temperature changes to adjust system operation, and works in conjunction with the dual chamber system to provide comprehensive temperature and load-based control. This multi-functionality reduces the need for separate components for each control function.

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

Solution Approach 2:

The system uses hydraulic principles to control the interaction between the two control chambers. The thermally adjustable control valve regulates hydraulic fluid flow to achieve temperature-based control of pump displacement and pressure, eliminating the need for complex mechanical or electronic control mechanisms.

Inventive Principle:
Principle #29Pneumatics and hydraulics

4Quantity of substance

If unnecessary high pressure is generated at low temperatures, then lubricant flow capability is maintained, but friction and CO2 emissions increase

Engineering Contradiction:
Improvelubricant flow rateVSAvoidfriction and CO2 emissions
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The control system adjusts pressure and displacement parameters based on temperature conditions. At low temperatures, the system maintains adequate lubricant flow rate through the dual control chamber mechanism while reducing pressure levels compared to single-chamber systems, thereby minimizing friction losses and associated CO2 emissions without compromising lubricant delivery.

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 solution reduces pump displacement and pressure at low temperatures, minimizing unnecessary lubricant flow and pressure, thereby improving engine efficiency, reducing friction, and lowering CO2 emissions.

Implementation Method 1

a thermally adjustable control valve, the thermally adjustable control valve configured for movement between a first valve position and a second valve position based on a temperature of the lubricant

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

In its first valve position, the thermally adjustable control valve is configured to control pressure in the second control chamber via fluid communication of the first port and the second port for delivery of pressurized lubricant through the control pressure channel into the second control chamber

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 3

In its second valve position, the thermally adjustable control valve is configured to control pressure in the second control chamber via venting pressurized lubricant from the second control chamber via the vent channel by communicating the second port to the third port or via the vent port

Methodology Applied
Scientific EffectPressure venting: Depressurisation

Data Source

PatentEP3099938B1Variable displacement vane pump with thermo-compensation
Publication Date: 2021.08.25 STACKPOLE INTERNATIONAL ENGINEERED PRODUCTS LTD
  • EP3099938B1 patent drawingFigure 1
  • EP3099938B1 patent drawingFigure 2~3
  • EP3099938B1 patent drawingFigure 4

AI summary

A variable displacement vane pump has a control slide displaceable within its housing and a first control chamber and a second control chamber for receiving pressurized lubricant. A thermally adjustable control valve is provided in the housing for adjusting pump displacement based on a temperature of the lubricant. In addition to fluid communication channels in the control chambers, at least one vent port is provided in the second chamber. The control valve is configured to control pressure and fluid communication between the chambers along with the control slide. The control valve can help reduce pump displacement at lower temperatures and low engine speeds. At lower temperatures, the second control chamber can be pressurized by the first control chamber. At higher temperatures, the second control chamber can be vented through the control valve and/or the vent port, despite the position of the control slide.