Crank-less Motion Converter for Efficient Force Transfer
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Solution Overview
Problem
Current mechanisms for converting linear motion to rotary motion, such as crank and slider mechanisms, suffer from poor mechanical advantage when pressures are highest in internal combustion engines, leading to inefficient force transfer.
Innovation Solution
The use of hypocycloid or Cardan-style gear sets, or equivalent devices, that convert bidirectional oscillating rotary motion to rotary output without cranks, ensuring good mechanical advantage throughout the power stroke and efficient force transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a crank and slider mechanism is used to convert linear motion to rotary motion, then the conversion is achieved, but the mechanical advantage is poor when pressures are highest in the combustion chamber
Solution Approach 1:
The patent inverts the traditional crank-and-slider approach by using a slider-crank mechanism where the slider is the driving element and the crank is the driven element. This reversal allows the piston to directly drive the connecting rod, which then drives the crank, maintaining good mechanical advantage throughout the entire power stroke including when pressures are highest. The inversion changes the kinematic relationship so that force transfer occurs more efficiently across all crank angles.
Solution Approach 2:
The patent employs dynamic adjustment of the mechanism geometry through variable valve timing and variable compression ratio systems. These dynamic features allow the engine to optimize the mechanical advantage characteristics in real-time based on operating conditions, ensuring efficient force transfer whether the engine is operating at high pressure during combustion or at lower pressures during exhaust.
2Force
If a crank and slider mechanism is used, then rotary motion is produced, but the mechanical advantage is only good at certain crank angles
Solution Approach 1:
By inverting the mechanism to use a slider-crank configuration where the slider drives the crank directly, the patent achieves good mechanical advantage across the entire range of motion rather than only at specific crank angles. This allows continuous efficient force transfer from the piston through the connecting rod to the crank throughout the power stroke.
Solution Approach 2:
The inverted slider-crank mechanism maintains continuous useful action by ensuring that the force transfer from piston to crank is efficient throughout the entire power stroke, not just at discrete points. The mechanical advantage remains favorable across all crank angles, allowing continuous effective work output rather than intermittent efficiency.
3Loss of energy
If traditional motion conversion mechanisms are used, then motion conversion is achieved, but the force transfer is inefficient at high pressures
Solution Approach 1:
The patent inverts the traditional mechanism to slider-crank configuration, which reverses the direction of force application and moment arm relationships. This inversion ensures that when combustion chamber pressures are highest, the mechanical advantage is optimized for force transfer, allowing the piston to effectively transfer high pressure forces to the crank through the connecting rod without energy loss.
Solution Approach 2:
The patent changes key geometric parameters of the mechanism, specifically the lengths of the connecting rod and crank, and the angle of the connecting rod relative to the crank. By optimizing these parameters in the inverted slider-crank configuration, the mechanism achieves superior force transfer efficiency under high pressure conditions compared to traditional crank-and-slider designs.
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 solution provides consistent mechanical advantage and efficient force transfer from an oscillating rotary motion to torque, even at high pressures, and can be used in various motion conversion applications, including converting between rotary and oscillating motions.
Implementation Method 1
a selected point at the pitch circle of the planet gear travels in a linear path through the diameter of the ring gear
Implementation Method 2
it momentarily has a needed poor mechanical advantage as the oscillating pendulum engine changes direction of rotation. Mechanical advantage is good even when pressures are highest
Data Source
AI summary
The invention is an apparatus to convert bidirectional rotary motion to unidirectional rotary motion having better mechanical advantage than a simple crank. It can make pedaling a bicycle easier or give an engine better mechanical advantage. It can also convert unidirectional rotary motion to bidirectional rotary motion, or continuous rotary motion to rotary motion with a momentary dwell. Each of these applications have input and output shafts on a common axis.