Variable Compression Piston Guide Pinion Rack Mismatch
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Solution Overview
Problem
The existing bearing guide devices for variable compression ratio engines experience premature wear and mechanical damage due to improper meshing and contact between the pinion and racks, caused by variations in the effective diameter of the cylindrical body and manufacturing inaccuracies, leading to desynchronization and forced contact during engine operation.
Innovation Solution
The bearing guide device is designed with adjustable circular pitches for the first and second racks, ensuring that the pinion rolls without forced contact outside of its positions, by having a different circular pitch than the pinion, and an effective diameter that is either smaller or greater than the pitch diameter of the pinion, to prevent premature wear and mechanical deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the effective diameter of the cylindrical body is made equal to the pitch diameter of the pinion, then the pinion and racks can mesh properly at top dead center and bottom dead center positions, but the cylindrical body cannot roll without slipping during intermediate positions due to diameter variations under load
Solution Approach 1:
The patent changes the geometric parameter relationship by making the effective diameter of the cylindrical body intentionally different from the pitch diameter of the pinion. This parameter difference allows the system to accommodate load-induced diameter variations while maintaining proper meshing throughout the entire range of motion, resolving the contradiction between reliability at extreme positions and precision during intermediate positions.
2Reliability
If the circular pitch of the racks is made equal to the circular pitch of the pinion, then the pinion can engage with the racks at required positions, but forced contact occurs during intermediate positions causing premature wear
Solution Approach 1:
The patent applies parameter changes by setting the circular pitch of the racks to be different from the circular pitch of the pinion. This creates a deliberate mismatch that prevents forced contact during intermediate positions, allowing the pinion to roll without slipping and thereby extending component lifespan while maintaining reliable engagement at the required top dead center and bottom dead center positions.
3Device complexity
If the synchronized roller uses a single fixed diameter cylindrical body, then the structure is simple, but the effective diameter varies under load causing desynchronization and premature wear
Solution Approach 1:
The patent introduces dynamics by allowing the effective diameter of the cylindrical body to vary under operational loads rather than maintaining a fixed diameter. This dynamic characteristic enables the synchronized roller to adapt to changing operational conditions, maintaining synchronization reliability throughout the range of motion while keeping the overall structure relatively simple.
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 configuration ensures rolling motion without slipping, reducing wear and mechanical damage by maintaining proper meshing and contact only at required positions, thereby extending the lifespan of the components.
Implementation Method 1
the cylindrical body 42 of the synchronized roller 40, placed between the synchronization plate 41 and the transmission unit 3, is in contact with the second and first rolling tracks or raceways 38, 48
Implementation Method 2
The adhesive movement of the cylindrical body 42 on the first and second rolling tracks or raceways 48, 38 of the synchronization plate 41 and the transmission unit 3
Implementation Method 3
The teeth of the pinion 44 are, in turn, received by the second and first racks 37, 46
Implementation Method 4
the flanks of the teeth of the pinion 44 then only bear against the flanks of the teeth of the first and/or second racks 46, 37
Data Source
AI summary
A bearing guide device of a combustion piston for a variable compression ratio engine. The movement of the combustion piston from a top dead center to a bottom dead center drives the movement of a synchronized roller made up of a cylindrical body and a pinion from a first position to a second position relative to first and second racks. According to the disclosure, the first and/or second racks have a different circular pitch than the pinion so that the flanks of the teeth of the pinion engage with the flanks of the teeth of the first and second racks only when the pinion is in the first or second position.