Adjustable Crank Transmission for Automatic Stroke Variation
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Solution Overview
Problem
Existing transmission elements for generating linear alternating motion, such as link rod-crank mechanisms, require manual reconfiguration of components for stroke adjustment, necessitating specialist labor and are prone to malfunctions due to complex controls and inertial stresses.
Innovation Solution
An adjustable transmission element with an interconnection apparatus between the motor shaft and crank, utilizing a cylindrical body and bell with complementary coupling means and an actuator, allowing automatic adjustment of the stroke without specialist intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If manual reconfiguration of components is used for stroke adjustment, then stroke adjustment is possible, but specialist labor and increased management costs are required
Solution Approach 1:
The system performs stroke adjustment automatically through the control unit coordinating the actuator and bell rotation, eliminating the need for specialist operators to manually reconfigure components. The machine serves itself by detecting desired stroke and executing adjustment autonomously
Solution Approach 2:
The bell is designed to be rotatable relative to the cylindrical body, allowing dynamic reconfiguration of the coupling means engagement. This rotational capability enables continuous stroke adjustment without disassembly, transforming a static rigid connection into a dynamically adjustable one
2Adaptability or versatility
If controlled motors with alternating rotation are used for variable stroke, then variable stroke is achieved, but sophisticated controls and heavy inertial stresses are required
Solution Approach 1:
Instead of controlling motor rotation direction alternately, the system dynamically adjusts stroke by rotating the bell to different angular positions while maintaining unidirectional motor rotation. This reduces control complexity from bidirectional alternating control to unidirectional positional control
Solution Approach 2:
The system changes the geometric parameter (bell rotation angle) to achieve variable stroke instead of changing the operational parameter (motor rotation direction). By varying the bell's angular position, different effective crank radii are achieved, providing variable stroke without complex alternating control
3Adaptability or versatility
If controlled motors with alternating rotation are used for variable stroke, then variable stroke is achieved, but frequent malfunctions occur due to heavy stresses
Solution Approach 1:
The bell rotation mechanism allows the system to achieve variable stroke with unidirectional motor rotation, eliminating the heavy inertial stresses caused by frequent direction changes. The dynamic reconfiguration is achieved through controlled bell rotation rather than motor reversal, reducing mechanical stress and improving reliability
Data Source
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AI summary
An adjustable transmission element (1) comprises a drive motor (2) provided with a rotating shaft (3) associated with a crank (4) which in turn is pivoted to a first end (5a) of a link rod (5) which has a second end (5b) which is pivoted to a sliding sled (6). An adjustable interconnection apparatus (8) is interposed between the shaft (3) of the motor (2) and the crank (4) and comprises: at least one cylindrical body (9), integral with the shaft (3), provided with first coupling means (10) and with at least one protruding stem (11) which is parallel to the shaft (3) and can move along a substantially radial stroke along the end face (9a) of the cylindrical body (9); at least one bell (13) provided with a cavity (14) with a shape substantially complementary to that of the cylindrical body (9), for its accommodation, and with second coupling means (15), complementary to the first coupling means (10), for the mechanical connection of the bell (13) to the cylindrical body (9) in a mutually coupled configuration. The bell (13) comprises a slot (16) in its end face which is substantially a spiral, regular or irregular, and is configured to accommodate the protruding stem (11). At least one actuator (17) configured for the translation of the bell (13) between a first configuration of partial separation from the cylindrical body (10), in which the first coupling means (10) and the second coupling means (15) are mutually facing, proximate, and not in mutual contact, and a second configuration of maximum proximity to the cylindrical body (9), in which the first coupling means (10) and the second coupling means (15) are in mutual contact, rendering the cylindrical body (9) and the bell (13) integral.