Speed Change Device with Segmented Cam Parts and Nested Gears
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Solution Overview
Problem
Conventional speed change devices face inefficiencies in speed conversion, precision, and structural rigidity due to friction between gears and the need for replacing multiple cam parts when adjustments are required, leading to increased volume and reduced practicality.
Innovation Solution
A speed change device design featuring a spindle with cam parts that can be disassembled and adjusted individually, along with rigid inner gears and secondary cam parts that enhance stability and conversion efficiency, utilizing multi-arc teeth and a secondary actuating mechanism to reduce friction and improve structural strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a plurality of cam parts are fixed on a spindle directly, then the structure is simple, but if one cam part is broken or adjustment is needed, all cam parts must be replaced along with the spindle
Solution Approach 1:
The invention divides the cam assembly into separable components: cam parts are no longer fixed directly to the spindle but are instead mounted on independent cam shafts that can rotate relative to the spindle. This segmentation allows individual cam parts to be replaced without replacing the entire spindle assembly, resolving the contradiction between structural simplicity and ease of repair.
2Power
If inner gear and outer gear face contact each other, then force transmission is achieved, but greater friction is produced influencing transmission
Solution Approach 1:
The invention introduces curved cam surfaces that convert rotational motion into controlled linear motion of the inner gear. Instead of direct face contact between gears, the cam mechanism uses curved surfaces to guide the inner gear's movement, reducing friction and improving force transmission efficiency while maintaining the required power transmission.
3Ease of manufacture
If there is a gap between cam part and inner gear, then assembly is easier, but conversion efficiency and precision are reduced due to insufficiency of rigidity
Solution Approach 1:
The invention creates a dynamic connection between the cam part and inner gear through a secondary actuating mechanism. The inner gear can rotate relative to the cam part while being constrained by the cam's curved surface, providing both ease of assembly and maintained precision through the mechanical guidance of the cam mechanism rather than relying solely on rigid fixed connections.
4Speed
If speed needs to be decreased or increased in a great extent, then speed change is achieved, but volume of the speed change device will increase
Solution Approach 1:
The invention places the inner gear inside the outer gear, creating a nested configuration where the inner gear rotates within the space occupied by the outer gear. This nesting allows for compact speed change mechanism that achieves significant speed variation ratios without increasing device volume, as the components share the same spatial envelope.
Data Source
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AI summary
A speed change device is provided, including: an outer ring part, an interior thereof including at least one outer gear; a spindle, coaxially pivoted to the outer ring part with the at least one outer gear, having a central axis, an outer circumference of the spindle having a plurality of cam assembling portions; a plurality of cam parts, respectively disassemblably assembled to the plurality of cam assembling portions, synchronizingly rotating with the spindle, at least two of the plurality of cam parts having a phase difference of angle which is larger than zero degree; a plurality of inner gears, being rigid, respectively sleeved on the plurality of cam parts and being non-rotatable with the plurality of the cam parts, respectively meshed with the at least one outer gear.