Camshaft Assembly Positioning Device for Phase Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In multi-cylinder engines, existing methods for assembling camshafts in undivided bearings face challenges in securely positioning cams to maintain precise phase alignment, leading to potential deviations that affect gas exchange and cylinder filling due to varying contact positions with assembly tools, especially when joining within a closed hood.

Innovation Solution

A device with positioning devices that hold cams in a predetermined phase position using negative profiles and additional holding forces, such as vacuum or mechanical forces, ensures secure contact and alignment during the joining process, facilitated by a centering mandrel for precise axial positioning and reduced need for manual alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If simple contact surfaces are used to hold and align cams during assembly, then the device complexity is reduced, but the manufacturing precision of cam phase positioning deteriorates

Engineering Contradiction:
Improveassembly tool designVSAvoidcam phase positioning
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-positioning the cams in the housing at their correct phase angles before the shaft insertion process. The cams are held in predetermined positions using positioning elements that engage with features on the cam surfaces, ensuring that when the shaft is inserted, the cams are already correctly aligned without requiring complex alignment procedures during the joining process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses positioning elements as intermediaries between the housing and the cams. These positioning elements engage with specific features on the cam surfaces and transfer the phase position information from the housing to the cams, ensuring precise angular positioning without requiring direct complex engagement between the assembly tool and each cam.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If cams are held with minimal contact surfaces, then the ease of operation is improved, but the reliability of phase position maintenance deteriorates

Engineering Contradiction:
Improvecam insertionVSAvoidphase position maintenance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by providing enhanced positioning features at specific locations on the cams and housing. Instead of requiring complex contact surfaces across the entire cam surface, the invention uses localized positioning elements that engage with specific features on the cam periphery or base circle, providing reliable phase position maintenance only where needed while keeping the rest of the cam surfaces simple for easy insertion.

Inventive Principle:
Principle #3Local quality

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 method ensures secure, phase-correct contact and alignment of cams during assembly, minimizing deviations and improving the joining process efficiency by maintaining precise positioning of cams and other functional elements, thereby enhancing the operational performance of camshafts in multi-cylinder engines.

Implementation Method 1

A device with positioning devices that hold cams in a predetermined phase position using negative profiles and additional holding forces, such as vacuum or mechanical forces

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

A device with positioning devices that hold cams in a predetermined phase position using negative profiles and additional holding forces, such as vacuum or mechanical forces, ensures secure contact and alignment during the joining process, facilitated by a centering mandrel for precise axial positioning

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

The connection of the elements to the shaft is force-fit, whereby shrink-fitting or internal high-pressure forming can be used

Methodology Applied
Scientific EffectShrink-fitting: Thermal Expansion

Implementation Method 4

The connection of the elements to the shaft is force-fit, whereby shrink-fitting or internal high-pressure forming can be used

Methodology Applied
Scientific EffectHigh-pressure forming: Compression

Data Source

PatentEP2237922B2Method and apparatus for assembling a composite, in particular comprising a camshaft and a housing
Publication Date: 2020.01.01 VOLKSWAGEN AG
  • EP2237922B2 patent drawingFigure 1~2
  • EP2237922B2 patent drawingFigure 3~4
  • EP2237922B2 patent drawingFigure 5~6

AI summary

The invention relates to an apparatus for assembling a composite comprising at least one shaft carrying functional elements, in particular comprising a mass-compensating shaft or camshaft, and a housing (2) supporting said shaft in undivided bearings, wherein the housing (2) has positioning devices (4) which, before the joining operation, hold the functional elements in a predetermined phase position in the housing (2) in such a manner that the at least one shaft can be pushed through the bearings of the housing (2) and openings (1b) in the functional elements, wherein the positioning device (4) is provided with recesses (4a) for the functional elements, said recesses having a stop (5) which supports the functional element counter to the joining direction of the shaft, wherein the recesses (4a) of the positioning devices (4) have a partial contour of the contour of the functional elements as a negative profile, and therefore the functional elements are held in a phase position in accordance with their joining position, wherein the partial contour of the recesses (4a) engages around at least part of the outer contour of the functional elements.