Bearing Cap Locating Projections for Accurate Engine Assembly
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Solution Overview
Problem
The use of ring dowels for connecting structural components in engines is costly, requires additional machining operations, reduces material strength, and poses challenges in assembly and disassembly due to press fit or interference fit, leading to stress and difficulty in achieving accurate positioning and repeatability.
Innovation Solution
An assembly comprising bearing caps with projection means that have externally facing contact surfaces and internally facing non-contact surfaces, which are designed to contact and not contact receptacles in the cylinder block respectively, allowing for accurate positioning while minimizing forces and stress, and are integrally formed to reduce production costs and assembly steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ring dowels are used for connecting structural components, then accurate positioning and repeatability of assembly are achieved, but production cost increases and additional machining operations are required
Solution Approach 1:
The locating function previously performed by separate ring dowels is merged into the bearing cap itself through integrally formed projection means. This eliminates the need for separate dowel components and their associated machining operations, reducing production cost while maintaining positioning accuracy through the integrated projection-receptacle interface.
Solution Approach 2:
The bearing cap is given multiple functions: it provides structural support for the bearing, enables component connection, and performs locating through its projection means. This multi-functionality eliminates the need for separate dedicated locating dowels, reducing the number of parts and machining operations required.
2Manufacturing precision
If ring dowels are used with press fit or interference fit, then locating accuracy is improved, but material strength is reduced due to removal of material in critical areas
Solution Approach 1:
The locating projections are integrally formed with the bearing cap body, eliminating the need for separate press-fit dowels that require material removal. The projection means are directly formed as part of the cap structure, preserving material continuity and strength in critical areas while providing accurate locating through the projection-receptacle interface.
3Manufacturing precision
If ring dowels are used for locating, then positioning repeatability is achieved, but device complexity increases due to additional assembly operations
Solution Approach 1:
The locating function is merged into the bearing cap structure through integrally formed projection means, eliminating separate dowel components. This reduces the number of parts to be assembled and the complexity of assembly operations while maintaining positioning repeatability through the integrated projection-receptacle interface.
Solution Approach 2:
The bearing cap performs multiple functions including structural support, connection, and locating through its projection means. This multi-functionality eliminates the need for separate dedicated locating components, simplifying the overall assembly process while maintaining positioning repeatability.
4Manufacturing precision
If press fit or interference fit is used to retain ring dowels, then locating accuracy is improved, but stress in components increases and disassembly becomes difficult
Solution Approach 1:
The locating projections are integrally formed with the bearing cap, eliminating the need for press-fit or interference-fit dowels. This removes the sources of stress concentrated at dowel interfaces while maintaining locating accuracy through the integrated projection-receptacle interface. The material continuity preserves strength and reduces stress in critical areas.
Data Source
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AI summary
A bearing cap for attachment to a cylinder block, the bearing cap comprising: receiving means for receiving a crankshaft bearing; contact means for contacting the cylinder block, and at least two projection means extending from the contact means for positioning the bearing cap on the cylinder block for attachment, wherein each of the projection means comprises an externally facing contact surface each of which is dimensioned to simultaneously contact a different receptacle of the cylinder block when positioning the bearing cap on the cylinder block for attachment, and an internally facing non-contact surface each of which is dimensioned to simultaneously not contact the respective receptacle of the cylinder block when positioning the bearing cap on the cylinder block for attachment.