Offset Piston Rod Geometry for Top Dead Centre Torque Gain
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Solution Overview
Problem
Current combustion engines face inefficiencies due to the perpendicular alignment of the piston rod to the crankshaft at top dead centre, leading to reduced torque efficiency and increased risk of piston rod damage, along with excessive weight and wear from piston skirts.
Innovation Solution
The engine design features a piston rod with a first hub coupled to the crankshaft, a second hub aligned parallel to the first hub, and a third hub offset laterally to allow the piston to reach top dead centre at an angle, reducing perpendicular thrust and enhancing torque efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the piston rod is aligned perpendicular to the crankshaft at top dead centre, then the combustion chamber size is minimized and compression is maximized, but the torque efficiency is reduced and the piston rod is subjected to excessive perpendicular thrust
Solution Approach 1:
The piston rod is designed with an asymmetric angular offset (α) relative to the crankshaft axis, rather than being perpendicular at top dead centre. This asymmetric configuration allows the piston rod to be offset by an angle α (5°-15°) from the perpendicular position, optimizing the torque transmission while maintaining effective compression.
Solution Approach 2:
The invention changes the geometric parameter of the piston rod-crankshaft alignment from a fixed perpendicular position to a variable angular offset (α). By adjusting this angle parameter, the system optimizes both the compression effectiveness and torque transmission efficiency simultaneously.
2Power
If the piston rod is aligned perpendicular to the crankshaft at top dead centre, then the combustion is maximized, but the piston rod is subjected to excessive perpendicular thrust that may cause bending or breaking
Solution Approach 1:
The piston rod is offset by an angle α from the perpendicular position to the crankshaft axis. This asymmetric alignment reduces the perpendicular thrust component acting on the piston rod, thereby decreasing the risk of bending or breaking while preserving combustion effectiveness.
Solution Approach 2:
The angular offset is designed in advance to counteract the harmful perpendicular thrust. By pre-positioning the piston rod at an offset angle, the design proactively prevents excessive stress concentrations that would otherwise occur at the perpendicular alignment point.
3Stability of the object's composition
If piston skirts are made tall to maintain vertical piston position, then the piston stability is improved, but the engine weight and inertia increase
Solution Approach 1:
The invention extracts the stability function from the tall piston skirts and transfers it to the piston rod's angular offset mechanism. By removing the excessive skirt height, the design eliminates unnecessary weight and inertia while maintaining piston stability through the offset alignment.
Solution Approach 2:
The mechanical support function previously provided by tall piston skirts is replaced by the angular offset configuration of the piston rod. This substitution eliminates the need for heavy skirts while achieving the same stability objective through geometric optimization.
4Stability of the object's composition
If piston skirts are made tall to maintain vertical piston position, then the piston remains substantially vertical, but the lower edges cause increased irregular wear on the cylinder walls
Solution Approach 1:
The invention removes the tall piston skirts that cause cylinder wear while extracting their stability function and transferring it to the piston rod's angular offset mechanism. This eliminates the harmful scraping action of skirt edges against cylinder walls.
Solution Approach 2:
The mechanical guidance function previously performed by tall piston skirts is replaced by the angular offset configuration. This substitution eliminates the harmful contact and wear between skirt edges and cylinder walls while maintaining piston alignment.
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 increases torque on the crankshaft, reduces piston weight and fuel consumption, decreases engine displacement, and significantly reduces CO and CO2 emissions by optimizing combustion at top dead centre.
Implementation Method 1
the piston rod comprises: a first hub arranged in its head for coupling with the crankshaft, a second hub arranged in its foot, and which is substantially aligned with or parallel to the first hub in the longitudinal direction of the cylinder when the crankshaft is in the upper or lower position, and a third hub also arranged in the foot of the piston rod, which is offset laterally towards the front with respect to the second hub
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a combustion engine (1), of the type that comprises a cylinder (4) with a piston (2) travelling through same, coupled by means of a piston rod (3) to a crankshaft (10), wherein the piston rod (3) comprises: - a first hub (5) in its head (30) for coupling with the crankshaft (10); - a second hub (6) in its foot (31) substantially aligned with or parallel to the first hub (5) in the longitudinal direction (40) of the cylinder when the crankshaft (10) is in the upper or lower position; and - a third hub (7) in its foot (31), which is offset laterally towards the front with respect to the second hub (6) in the direction of rotation of the crankshaft (10); - the piston (2) being coupled with the third hub (7), - comprising a guide (9) for the travel of the piston rod (3) coupled with the second hub (6), and - the piston (2) being coupled with the third hub (7) via a link rod (8).