Dwell Cycle Crank With Rollers Reduces Wear
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Solution Overview
Problem
Conventional dwell cycle cranks experience inefficiencies due to heavy contact points between the follower and the S-shaped cam, leading to wear and potential engine failure, which reduces performance and efficiency.
Innovation Solution
The introduction of top and bottom rollers with removed portions that fit the follower, allowing it to ride in an S-shaped pattern within a body, creating a constant surface contact and reducing wear, while maintaining the S-shaped cam functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the follower directly contacts the S-shaped cam surface, then the mechanism achieves the required S-shaped motion pattern, but heavy contact points cause excessive wear and reduced reliability
Solution Approach 1:
Rollers are introduced as intermediary elements between the follower and the S-shaped cam surface. The rollers rotate as the follower moves through the S-shaped pattern, converting direct sliding contact into rolling contact. This mediator reduces friction and wear at the contact points while maintaining the required motion pattern, thereby improving crank reliability and extending service life
2Reliability
If the follower rides directly on the S-shaped cam, then the structure remains simple, but heavy contact points lead to performance degradation and engine failure
Solution Approach 1:
The follower structure is segmented by incorporating multiple rollers (typically three rollers arranged in a triangular pattern) instead of a single solid follower. Each roller independently contacts the S-shaped cam surface, distributing the contact loads and reducing wear at any single point. This segmentation maintains relatively simple individual components while significantly improving overall reliability and performance
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 enhances volumetric and geometric efficiencies by minimizing wear and maximizing energy conversion, leading to improved engine performance and extended crank life.
Implementation Method 1
The top and bottom rollers are positioned within the body where each roller is adapted to rotate for allowing the follower to ride between the rollers within the body in an S-shaped pattern
Data Source
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AI summary
A dwell cycle crank configuration for converting reciprocating linear motion to rotary motion includes: a follower, a top roller, a bottom roller, and a body. The top roller has a bottom portion removed. The removed bottom portion of the top roller is adapted to fit the top of the follower. The bottom roller has a top portion removed. The removed top portion of the bottom roller is adapted to fit the bottom of said follower. The top and bottom rollers are positioned within the body where each roller is adapted to rotate for allowing the follower to ride between the rollers within the body in an S- shaped pattern.