Variable Stroke Engine Oil Supply Hole Positioning
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Solution Overview
Problem
In link type variable stroke engines, oil supply holes are prone to leakage due to the dynamic application of loads and reaction forces, leading to inefficient lubrication between the sub connecting rod and crank pin.
Innovation Solution
The oil supply hole is positioned in the upper portion of the sub connecting rod's connection tubular part, deviated from the maximum load direction and behind the point of maximum load application, with a design that includes facing plate parts and a connection plate to ensure reliable oil collection and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the oil supply hole is formed at the connection tubular part of the sub connecting rod to lubricate the position between the connection tubular part and the crank pin, then lubrication is provided, but oil leaks out from the oil supply hole under application of maximum load by maximum in-tube pressure
Solution Approach 1:
The patent applies local quality by positioning the oil supply hole at a specific location on the connection tubular part where it is deviated from the direction of maximum load application. This localized positioning ensures that the oil supply hole is situated in a region less subjected to maximum in-tube pressure, preventing oil leakage while maintaining effective lubrication delivery to the connection tubular part and crank pin interface.
2Productivity
If the oil supply hole is positioned in the direction of maximum load application, then oil delivery is direct, but oil leaks out under maximum in-tube pressure
Solution Approach 1:
The patent applies parameter changes by altering the positional parameter of the oil supply hole on the connection tubular part. Specifically, the oil supply hole is positioned at a location deviated from the direction of maximum load application, changing the spatial parameter to reduce exposure to maximum in-tube pressure while maintaining sufficient oil delivery efficiency through the lubrication system.
3Object-generated harmful factors
If the oil supply hole is positioned away from the maximum load direction, then oil leakage is prevented, but oil delivery path is longer
Solution Approach 1:
The patent applies partial or excessive action by positioning the oil supply hole at a location that is deviated from but not completely opposite to the maximum load direction. This partial deviation is sufficient to prevent oil leakage under maximum in-tube pressure while keeping the oil delivery path length within acceptable limits, achieving a balance between leakage prevention and delivery efficiency.
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
This configuration prevents oil leakage and maintains an efficient oil film, ensuring reliable lubrication even under maximum load conditions, enhancing the engine's operational efficiency.
Implementation Method 1
oil scattered in the crankcase is guided to a position between the connection tubular part of the sub connecting rod and the crank pin
Data Source
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AI summary
In a link type variable stroke engine in which a piston, a crankshaft (17) and an eccentric shaft (33) are linked by a linking mechanism, an oil supply hole (70) for supplying lubricating oil to a position between a connection tubular part (57) of a sub connecting rod (58A) and a crank pin (17C) is provided in an upper portion of the connection tubular part at a position which is deviated from a direction of application of maximum load applied from the crank pin to an inner surface of the connection tubular part (57) by maximum in-tube pressure, and which is immediately behind a point of application of the maximum load along a direction in which the crank pin rotates relative to the sub connecting rod. Accordingly, it is possible to prevent leak of oil from the oil supply hole and thereby reliably lubricating the position between the connection tubular part of the sub connecting rod and the crank pin by a splash lubrication system.