Switchable Clutch Mechanism for Motor Vehicle Vacuum Pump

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Solution Overview

Problem

Mechanical motor vehicle vacuum pumps require high shifting forces to operate the friction clutch reliably and safely, leading to increased wear and energy consumption.

Innovation Solution

A switchable, positively locking clutch arrangement with a bolt holder, guide body, and catch body that uses radial bolt guides and an inclined guiding surface to achieve positive engagement with minimal actuation force, allowing for hydraulic actuation and fail-safe operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a friction clutch is used for reliable and fail-safe operation, then the clutch can be pre-tensioned to the engaged state, but great opening forces are required to open the clutch

Engineering Contradiction:

Improvereliable operationVSAvoidopening force

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The patent replaces the friction-based mechanical clutch system with a positively locking clutch mechanism using a bolt body, bolt guide, and catch body with catch depression. This substitution eliminates the need for high pre-tensioning forces while maintaining reliable engagement through geometric interlocking rather than friction.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention extracts the essential function of positive locking from the friction clutch system by introducing a separate bolt-and-catch mechanism. The bolt body with radial extension and catch depression create a dedicated positive locking subsystem that operates independently from friction-based engagement.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If a friction clutch is used for fail-safe design, then the clutch can be pre-tensioned to the engaged state, but great shifting forces are required, leading to increased wear and energy consumption

Engineering Contradiction:

Improvefail-safe designVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the energy-intensive friction clutch system with a positively locking mechanism that requires minimal shifting forces. The geometric interlocking of the bolt body and catch body eliminates the need for continuous friction-based pre-tensioning, significantly reducing energy consumption while maintaining fail-safe operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention extracts the positive locking function from the friction clutch system, creating a separate bolt-and-catch mechanism that provides fail-safe engagement without the energy penalties of friction-based pre-tensioning and shifting.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If a friction clutch is used for reliable operation, then the clutch can be pre-tensioned to the engaged state, but great opening forces are required to open the clutch

Engineering Contradiction:

Improvereliable operationVSAvoidclutch arrangement complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the positive locking function from the friction clutch system, creating a separate but integrated bolt-and-catch mechanism. This extracted subsystem adds geometric complexity but eliminates the need for complex friction control and high-force actuation systems.

Inventive Principle:

Principle #2Taking out (Extraction)

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 the required shifting forces, enhances torque transmission reliability, and minimizes energy consumption by enabling the clutch to engage and disengage with low actuation forces, ensuring a fail-safe operation.

Implementation Method 1

The bolt body is forced radially into a locking position via the guiding surface

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

The guide body comprises a guiding surface which is inclined with respect to an axial plane. The bolt body is forced radially into a locking position via the guiding surface

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentUS10161402B2Motor vehicle vacuum pump having a switchable clutch

Publication Date: 2018.12.25 PIERBURG PUMP TECH

AI summary

A motor vehicle vacuum pump includes a pump rotor, a coupling element, and a clutch arrangement. The clutch arrangement locks or releases the coupling element to/from the pump rotor so that the coupling element rotates together with or is released from the pump rotor. The clutch arrangement comprises a bolt holder connected to the pump rotor or to the coupling element to rotate therewith, an axially displaceable guide body, and a catch body connected to the coupling element or to the pump rotor to rotate therewith. The bolt holder comprises a bolt guide and a bolt body displaceable therein. The guide body is assigned to the bolt holder and comprises a guiding surface inclined with respect to an axial plane. The bolt body is forced radially into a locking position via the guiding surface. The catch body has a catch depression wherewith the bolt body engages in the locking position.