Rotary Engine Seal Arrangement Reducing Gas Leakage
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Solution Overview
Problem
Existing rotary internal combustion engines, such as Wankel engines, face inefficiencies due to gaps between seal members caused by manufacturing tolerances and differential thermal expansions, leading to leakage issues between working chambers and the oil-exposed central portion of the rotor cavity.
Innovation Solution
A rotor design with axially spaced end faces and a peripheral face defining apex portions, featuring apex seals, face seals, and end seals, with feather seals connecting the junctions between these to enhance sealing engagement and reduce leakage, utilizing a combination of apex, face, and end seals biased against the rotor's peripheral and end walls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional seal members are used with gaps between adjacent seals, then manufacturing is simpler, but gas leakage occurs between working chambers and oil system
Solution Approach 1:
The patent merges adjacent seal members into a single integrated seal member that spans multiple junctions. This eliminates the gaps between separate seals while maintaining sealing effectiveness across multiple working chamber boundaries, directly resolving the contradiction between sealing reliability and structural complexity
Solution Approach 2:
The patent introduces an intermediary sealing structure that bridges the gap between traditional separate seal members and the requirement for continuous sealing. This intermediary design allows multiple seal functions to be combined while maintaining the necessary sealing performance against gas leakage
2Reliability
If multiple separate seal members are used at junctions, then sealing coverage is improved, but gaps occur due to manufacturing tolerances and thermal expansion
Solution Approach 1:
By combining multiple separate seal members into a single integrated seal structure, the patent eliminates the manufacturing tolerance accumulation that occurs with multiple separate components. This unified design ensures consistent sealing performance without the gap control issues inherent in assembling multiple separate seals
Solution Approach 2:
The patent changes the structural parameter of the seal system from multiple discrete components to a single continuous seal member. This parameter change fundamentally alters how manufacturing tolerances and thermal expansions are managed, eliminating the gaps that occur when multiple separate seals are assembled together
3Reliability
If face seals and end seals are interconnected through intermediate seals, then sealing coverage is improved, but gaps occur at the junction due to manufacturing tolerances
Solution Approach 1:
The patent merges the face seal and end seal into a single integrated seal member, eliminating the need for intermediate seals and their associated junctions. This integration simplifies the manufacturing process by reducing the number of separate components that need to be assembled while maintaining comprehensive sealing coverage
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 improved seal arrangement effectively reduces gas leakage into the oil system, enhancing engine performance, lowering oil temperature, and minimizing oil contamination by combustion by-products, thereby improving engine efficiency and reliability.
Implementation Method 1
apex seals, face seals, and end seals, with feather seals connecting the junctions between these to enhance sealing engagement and reduce leakage
Data Source
AI summary
A rotor of a rotary internal combustion engine, with each of the end faces having at each of the apex portions a recess defined therein in communication with the at least one apex groove, an end seal received in the recess in sealing engagement with the apex seal of each of the at least one apex groove, a first seal member in sealing engagement with the end seal and with the face seal of the face groove defined between the apex portion and a first one of the adjacent apex portions, and a second seal member in sealing engagement with the end seal and with the face seal of the face groove defined between the apex portion and a second one of the adjacent apex portions.