Engine Transmission Linkage for Thermal Expansion Alignment Control
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Solution Overview
Problem
In engines with variable compression rate and/or displacement, uncontrolled differential expansion between materials leads to excessive wear and friction due to uncontrolled positions of equilibrium among moving members, resulting in reduced efficiency and increased noise.
Innovation Solution
A transmission device with controlled links between the combustion piston, gear, connecting rod, and crankshaft, utilizing annular and straight linear links to maintain alignment and accommodate disturbances, thereby minimizing friction and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If differential expansion between steel crankshaft and aluminum cylinder housing is allowed, then weight is reduced and materials are optimized, but the position of mobile members becomes uncontrolled leading to excessive wear and friction
Solution Approach 1:
A control member is introduced as an intermediary element between the gear and the cylinder housing. This control member includes a control piston that can move along the axis of the cylinder, and it engages with the gear to control its position. The control member acts as a mediator that compensates for the differential expansion between the steel crankshaft and aluminum cylinder housing, maintaining proper alignment and preventing excessive wear and friction while allowing the use of lightweight materials.
2Ease of operation
If mobile members are allowed to move to equilibrium positions, then freedom of movement is increased, but alignment with design positions is lost causing friction and wear
Solution Approach 1:
The control member establishes a feedback mechanism where the control piston responds to position deviations of the gear from its design position. When thermal expansion or other disturbances cause the gear to move away from its intended position, the control piston detects this deviation and adjusts the gear's position accordingly, providing continuous feedback control that maintains alignment precision while allowing for operational movements.
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
The solution effectively controls the operating position of mobile members, reducing friction and wear, enhancing engine efficiency and power transmission while maintaining alignment despite material expansion and other disturbances.
Implementation Method 1
a combustion piston (2), capable of moving in a combustion cylinder (110) of the engine
Implementation Method 2
the differential expansion between the various materials of the parts, results in a movement of the mobile members of the transmission device with respect to each other
Data Source
AI summary
A transmission device, particularly for an engine with variable compression rate and/or variable displacement, includes, in a cylinder housing: a combustion piston capable of moving in a combustion cylinder of the engine and secured to a transmission member; a gear engaging with a first rack of the transmission member and providing transmission of the movement between the combustion piston and a crankshaft of the engine; a connecting rod engaging, at a first end, with the gear and, at a second end, with the crankshaft; and a control member engaging with the gear and secured to a control piston. The combustion piston and the transmission member are slidably linked with the cylinder housing in a main direction.