Modular Overhead Cam Support for Engine Block Strength
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Solution Overview
Problem
Large diesel and natural gas engines with cam-in-block designs face issues such as reduced strength and stiffness in the cylinder block, increased mass and complexity, and limitations in serviceability due to the camshaft being integrated with the cylinder head, which restricts flexibility and increases maintenance challenges.
Innovation Solution
A modular overhead cam support system mounted independently to the engine cylinder block, allowing for variable valve train configurations, including cam phasing and variable valve lift, and enabling the use of shorter cylinder heads for improved serviceability and reduced mass, with scalable camshaft arrangements and hydraulic lash adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If cam-in-block design is used, then the camshaft is integrated with the cylinder block, but this reduces the strength and stiffness of the cylinder block
Solution Approach 1:
The camshaft is extracted from the cylinder block and relocated to an overhead position on the cylinder head. This separation eliminates the weakening effect of cam-in-block design on the block structure while maintaining the functional integration of the valve train system.
Solution Approach 2:
The camshaft positioning transitions from a horizontal in-block arrangement to a vertical overhead arrangement on the cylinder head. This dimensional change allows the camshaft to be supported by the cylinder head rather than the block, preserving block structural integrity.
2Adaptability or versatility
If camshaft is moved to overhead position on cylinder head, then various valve train arrangements can be implemented, but this increases the mass and complexity of the cylinder head system
Solution Approach 1:
The overhead cam support system is divided into modular components including the cylinder head, camshaft, and valve train elements. This segmentation allows for independent design optimization of each component and facilitates easier maintenance and replacement of individual parts.
Solution Approach 2:
The overhead cam support structure on the cylinder head is designed to accommodate multiple valve train configurations and arrangements. This universal design allows the same basic structure to support various camshaft positions, valve train types, and actuation mechanisms.
3Speed
If long multi-cylinder slab heads are used to support overhead camshaft, then the camshaft can be positioned overhead, but this reduces serviceability and increases repair time
Solution Approach 1:
The engine is divided into separate cylinder head assemblies that can be independently removed and serviced. This segmentation allows mechanics to access and repair the overhead camshaft and valve train components by removing individual cylinder heads rather than disassembling the entire engine.
Solution Approach 2:
The modular cylinder head assembly acts as an intermediary unit between the engine block and the overhead camshaft system. This intermediate structure allows the camshaft to be positioned overhead while enabling easy serviceability by treating the entire head assembly as a removable service unit.
4Device complexity
If cam-in-block design with push rod driven valve train is used, then the structure is simplified, but this increases valve train inertia and energy losses
Solution Approach 1:
The camshaft is extracted from the block and positioned overhead, eliminating the need for push rods and complex valve train mechanisms. This direct overhead cam arrangement reduces the number of moving parts and decreases valve train inertia, resulting in lower energy losses.
Solution Approach 2:
Instead of using a push rod driven valve train where the camshaft is in the block, the design inverts the arrangement by placing the camshaft overhead with direct actuation of the valves. This inversion eliminates the intermediary push rods and reduces the overall valve train mass and inertia.
Data Source
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AI summary
Systems, devices, and methods are disclosed for supporting one or more camshafts by the engine block in overhead arrangement relative to the cylinder heads and valve train.