Compact Speed Reducer with Reduced Gear Meshing Points
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Solution Overview
Problem
Conventional speed reduction devices with external gears are large in size, noisy, and suffer from significant energy loss due to complex structures and multiple gear meshing points.
Innovation Solution
A speed reduction device combining a pre-stage speed reducer with external gears and an eccentrically oscillating speed reducer, featuring two-stage gears supported by a carrier, reducing the number of meshing points and simplifying the structure, while allowing for increased diameter of large-diameter gears for enhanced speed reduction ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If three-stage external gears are arranged close to each other at an axial end of crankshafts, then the speed reduction ratio is increased, but the axial length and overall size of the device become large
Solution Approach 1:
The patent redistributes gear arrangements from a concentrated axial configuration to a spatial distribution across multiple dimensions. The third external gear is positioned at the radial outside of the imaginary circle passing through crankshaft central axes, utilizing radial space rather than only axial space. This dimensional redistribution reduces axial length while maintaining the three-stage speed reduction capability.
2Power
If gears mesh in three places (first external gear with large-diameter gears, small-diameter gears with large-diameter gears, small-diameter gears with second external gears), then the speed reduction ratio is increased, but noise and energy loss increase
Solution Approach 1:
The patent extracts and eliminates the intermediate meshing stage between small-diameter gears and large-diameter gears. By directly connecting the first external gear to the third external gear through the supporting shaft mechanism, and having the third external gear directly drive the second external gear, the design removes one meshing interface. This extraction reduces energy loss and noise while preserving the three-stage speed reduction function.
3Power
If two types of gears (third and fourth external gears) with both large-diameter and small-diameter gears are used, then the speed reduction ratio is increased, but the structure becomes complicated
Solution Approach 1:
The patent merges the functions of the third and fourth external gears into a single third external gear. This consolidated gear integrates both the large-diameter gear function (meshing with the first external gear) and the small-diameter gear function (meshing with the second external gear) into one component. The supporting shaft mechanism enables this merged gear to perform both speed reduction stages, simplifying the overall structure while maintaining the three-stage speed reduction capability.
Data Source
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AI summary
A low-noise speed reduction device that is simple in structure, small-sized, and little in energy loss is provided. Two-stage gears, i.e., a large-diameter gear 65 and a small-diameter gear 66 of a third external gear 63 are supported by a supporting shaft 59, and one-stage second external gear 58 that meshes with the small-diameter gear 66 is only attached to an axial one end of a crankshaft 40. Therefore, the axial length of the whole speed reduction device becomes short, and consequently, miniaturization becomes possible. Further, since gears mesh with each other only in two places until a driving force is transmitted to the crankshaft 40 from the first external gear 54, noises can be reduced, and energy loss can also be lowered.