Rotary Engine CMC Side Plates for Wear and Thermal Deflection
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Solution Overview
Problem
Rotary engine side plates face challenges in withstanding high temperatures and pressure forces, with existing materials like aluminum and silicon carbide exhibiting poor wear-resistance and thermal expansion issues.
Innovation Solution
The use of a ceramic matrix composite (CMC) material for the side plates, incorporating ceramic fibers in a ceramic material matrix, provides enhanced durability and resistance to crack propagation, with ceramic layers at the seal, interior, and outer edge surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If aluminum material is used for side plates, then weight is reduced and ease of manufacture is improved, but wear-resistance deteriorates
Solution Approach 1:
The side plate uses a composite structure combining aluminum alloy base material with ceramic coating layers (silicon carbide or silicon oxide). This composite approach allows the side plate to maintain the lightweight advantage of aluminum while gaining the wear-resistance properties of ceramic materials through the coated surface layer.
2Reliability
If silicon carbide material is used for side plates, then wear-resistance is improved, but thermal expansion issues worsen
Solution Approach 1:
The side plate employs a composite structure with aluminum alloy base and ceramic coating layers. The aluminum alloy provides stable thermal expansion characteristics, while the ceramic coating (silicon carbide or silicon oxide) provides wear-resistance. This composite approach balances both requirements by combining materials with complementary properties.
Solution Approach 2:
The ceramic coating is applied specifically to the seal surface where wear-resistance is most critical, while the bulk aluminum alloy material maintains thermal expansion stability. This local application of different material properties optimizes performance where needed without compromising overall thermal stability.
3Reliability
If ceramic matrix composite is used for side plates, then resistance to wear and thermal deflection is improved, but manufacturing complexity increases
Solution Approach 1:
The side plate uses a composite structure combining aluminum alloy base material with ceramic coating layers. This approach provides improved resistance to wear and thermal deflection compared to pure aluminum, while avoiding the extreme manufacturing complexity of solid ceramic components. The coating process is more manageable than forming solid CMC structures.
Solution Approach 2:
The invention changes the surface properties of the side plate by applying ceramic coatings, rather than changing the bulk material properties. This parameter change (surface treatment vs. bulk material change) achieves improved wear and thermal resistance without the full complexity of manufacturing solid ceramic matrix composite components.
Data Source
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AI summary
A rotary internal combustion engine (20) includes a housing (22) and a rotor (24). The housing (22) includes first and second side housings (28, 30) and a center housing (32). The center housing (32) is disposed between and attached to the first and second side housings (28, 30). The rotor (24) is disposed within a rotor chamber (36) and is engaged with a rotor shaft (26) that extends between the first and second side housings (28, 30). The rotor (24) has a peripheral side wall (40) that extends between a pair of end face surfaces (42). At least one of the first side housing (28) or the second side housing (30) includes a side plate (34) having a seal surface (78), an interior surface (80), and a core (86) disposed between the seal surface (78) and the interior surface (80). The core (86) comprises a ceramic matrix composite (CMC) material. The seal surface (78) of the side plate (34) engages in a sealing arrangement with a respective rotor end face surface (42).