Angled Crankcase Sealing Surface for Compact Engine Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing internal combustion engine designs face challenges in compactness due to the length of the cylinder crankcase and oil pan sealing, particularly in engines with overhead camshafts and gear-driven systems, where the gear drive affects the oil sump sealing surface, leading to tolerance issues and the need for extension components to connect components like gears and flywheel.
Innovation Solution
The crankcase is modified with a machining of the sealing surface on the side with the wheel drive at an angle of about 4° relative to the oil pan flange, allowing a one-piece or two-piece timing case cover to form a complementary sealing counter-contour, reducing the overall engine length without the disadvantages of multi-part crankshafts, and ensuring precise centering and secure fastening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the crankcase is designed with a conventional vertical sealing surface for the timing case cover, then the sealing is straightforward and easy to manufacture, but the overall length of the crankcase and engine increases
Solution Approach 1:
The patent applies asymmetry by tilting the sealing surface of the timing case cover at an angle of 4° to 10° relative to the perpendicular of the oil pan flange surface. This asymmetric angular orientation allows the timing case cover to overlap with the cylinder head gasket surface, enabling the gear wheel passage to remain sealed while reducing the crankcase length by approximately 10mm compared to conventional vertical sealing designs.
2Length of stationary object
If the crankcase length is reduced to improve compactness, then the engine becomes more compact, but the crankshaft becomes too short requiring extension components
Solution Approach 1:
The patent resolves this contradiction by changing the dimensional approach from extending the crankshaft axially (adding components) to tilting the sealing surface angularly (using the 4° to 10° inclination). This allows the timing case cover to extend into the cylinder head gasket surface area, effectively reducing crankcase length in the axial direction while maintaining sufficient crankshaft length and eliminating the need for extension components.
3Device complexity
If the timing case cover is designed to seal both the cylinder head and oil pan, then the number of components is reduced, but tolerance accumulation leads to sealing cracks
Solution Approach 1:
The patent maintains segmentation by keeping the timing case cover as a separate component from both the cylinder head and oil pan. The tilted sealing surface design allows the timing case cover to be precisely positioned and sealed against the cylinder head gasket surface at an angle, preventing tolerance accumulation that would occur if a single component tried to seal both interfaces. This segmented approach ensures reliable sealing while maintaining component independence.
4Length of stationary object
If the sealing surface is tilted at an angle, then the crankcase length is reduced, but the fastening screws must accommodate the angular misalignment
Solution Approach 1:
The patent uses the tilted sealing surface itself as an intermediary that facilitates proper alignment. The 4° to 10° angle of the sealing surface allows the fastening screws to be oriented perpendicular to the tilted surface, naturally centering the timing case cover over the crankshaft. This angular intermediary surface eliminates the need for separate centering mechanisms and ensures precise alignment during assembly while maintaining the reduced crankcase length.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A crankcase for an internal combustion engine and an internal combustion engine with at least one oil pan flange and one-piece crankshaft are described, wherein at least one end face of the crankcase, on which, for example, the gear drive is arranged, has a machining of the sealing surface towards the gear case cover, which is arranged at an angle of approximately 94° to the perpendicular to the oil pan flange surface.