Vane Pump Overheating Protection via Thermal Braking

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Solution Overview

Problem

Vane pumps face overheating issues when running dry, particularly in vehicles where pressure relief mechanisms like compressed air may not be available, and existing overpressure protection methods are inadequate for explosion protection and mechanical switching.

Innovation Solution

Incorporation of a braking or blocking element, such as a bimetallic spring or expanding material, that engages mechanically to prevent vanes from emerging from recesses above a predetermined temperature, ensuring the pump stops operation and prevents further temperature increase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressure relief valves are used to protect against overpressure, then pressure can be reduced to almost zero in a controlled manner, but these valves require compressed air which is not always available on vehicles

Engineering Contradiction:
Improveoverpressure protectionVSAvoidcompressed air requirement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The braking element is designed to automatically activate when the pump runs dry or against closed valves, without requiring external control systems or compressed air. The element self-actuates based on the operating conditions, making the system self-sufficient and eliminating the need for auxiliary compressed air supplies.

Inventive Principle:
Principle #25Self-service

2Reliability

If thermostats are used to switch off the pump when a certain temperature is reached, then overheating protection is provided, but such shutdown is not easily implemented when the pump is mounted on a vehicle and control systems must meet minimum functional safety requirements

Engineering Contradiction:
Improveoverheating protectionVSAvoidcontrol system requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex electronic control systems and thermostats with a purely mechanical braking element that automatically engages when the pump runs dry or against closed valves. This mechanical solution eliminates the need for electronic control systems, sensors, and wiring, thereby meeting functional safety requirements without complex electronics.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the pump continues to operate during dry running or against closed valves, then productivity is maintained, but heat generation can lead to a fire

Engineering Contradiction:
Improvecontinuous operationVSAvoidheat generation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The braking element is designed to prevent the harmful action (overheating and fire) before it can occur by automatically engaging when the pump runs dry or against closed valves. By applying the braking force in advance, the system prevents the temperature from rising to dangerous levels, thereby eliminating the fire hazard before it can materialize.

Inventive Principle:
Principle #9Preliminary anti-action

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 provides reliable overheating protection by mechanically preventing vanes from contacting the cylinder wall, thus avoiding temperature rise and allowing safe operation once temperatures normalize, ensuring functional safety and explosion protection without reliance on compressed air.

Implementation Method 1

This is achieved with a thermally expanding material or a thermally expanding metal

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

at least one braking or locking element is arranged in the vanes or in the walls of the recesses. This element is movable between a braking or locking position, in which it interacts with the wall of the recess or the vane in a fluid or force-like manner

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP3631169B1Vane pump or compressor
Publication Date: 2021.03.17 SAETA GMBH & CO KG
  • EP3631169B1 patent drawingFigure 1
  • EP3631169B1 patent drawingFigure 2
  • EP3631169B1 patent drawingFigure 3~4

AI summary

The invention relates to a vane pump or compressor, comprising a housing in which a rotor is mounted such that it rotates about an axis of rotation, and vanes that are movably arranged in radial recesses of the rotor, the vane ends opposite the bottom of the recess interacting with the wall of a cylindrical chamber in the housing under the action of a centrifugal force, the axis of rotation being eccentric to the axis of the cylindrical chamber and the cylindrical chamber comprising a suction channel and a pressure channel. At least one braking or locking element is arranged in the vanes or in the wall of the recesses, said braking or locking element being movable between a locking position or braking position, in which it can interact positively or non-positively with the wall of the recess or the vane, and a release position in which the vane moves freely in the recess. From a pre-defined temperature, the braking or locking element can be brought into the braking or locking position by heat expansion of the element or an additional expanding object.