Reduction Gear Axial Positioning for Low Sliding Resistance
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Solution Overview
Problem
In reduction gears where the bearing lacks an inner or outer ring, the externally toothed gear experiences high sliding resistance due to position restriction by side members, leading to increased energy transmission loss.
Innovation Solution
The implementation of a configuration where the first position restriction member is fixed to the shaft and the second position restriction member is fixed to the externally toothed gear, restricting axial movement of the rolling element and gear respectively, reducing sliding resistance by using an inner ring press-fitted to the shaft and a snap ring integrated with the externally toothed gear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the externally toothed gear is rotatably externally fitted to the input shaft without position restriction, then the gear can rotate freely, but axial movements of the gear cause sliding resistance and reduced transmission efficiency
Solution Approach 1:
A bearing is introduced as an intermediary component between the externally toothed gear and the input shaft. The bearing includes rollers that mediate the interaction between these components, converting sliding friction into rolling friction and thereby reducing sliding resistance while maintaining reliable power transmission.
Solution Approach 2:
The friction parameter is changed by transitioning from direct sliding contact between the gear and shaft to rolling contact through the bearing. This parameter change reduces the coefficient of friction and minimizes energy loss due to sliding resistance.
2Device complexity
If the bearing is configured with the externally toothed gear as the outer ring, then the structure is simplified, but axial movements of the bearing rollers must be restricted to function properly
Solution Approach 1:
The position restriction function is segmented into two separate components: a first position restriction member (collar) attached to the input shaft and a second position restriction member (snap ring) attached to the externally toothed gear. This segmentation allows each component to perform its specific restriction function independently, simplifying the overall structure while ensuring proper roller constraint.
Solution Approach 2:
The position restriction functions are merged with the existing bearing components by integrating the first position restriction member with the input shaft and the second position restriction member with the externally toothed gear. This merging eliminates the need for separate restriction mechanisms, simplifying the overall device structure.
3Reliability
If position restriction members are added to restrict axial movements, then transmission efficiency is improved, but the device complexity increases
Solution Approach 1:
The first position restriction member (collar) serves multiple functions: it restricts axial movement of the bearing rollers and can be integrated with the input shaft structure. The second position restriction member (snap ring) similarly serves both to restrict roller movement and can be incorporated into the gear structure, making these components multi-functional and reducing the need for additional separate parts.
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 achieves high transmission efficiency by minimizing sliding resistance during position restriction of the externally toothed gear, reducing energy loss in the reduction gear.
Implementation Method 1
a bearing (B2) which is disposed between the input shaft (16) and the externally toothed gear (26), in which the externally toothed gear (26) serves as an outer ring of the bearing (B2)
Data Source
Figure 1
Figure 2
Figure 3(A)~3(C)
AI summary
A reduction gear having high transmission efficiency is obtained by performing position restriction in an axial direction of an externally toothed gear which is rotatably externally fitted to a shaft, with a configuration having small sliding resistance. A reduction gear (G1) has an input shaft (16), an externally toothed gear (26) which is externally fitted to the input shaft (16), and a bearing (B2) which is disposed between the input shaft (16) and the externally toothed gear (26), in which the externally toothed gear (26) serves as an outer ring of the bearing (B2), and axial movements of rollers (62, 63) of the bearing (B2) are restricted by an inner ring (a first position restriction member) (60) fixed to the input shaft (16) and a snap ring (a second position restriction member) fixed to the externally toothed gear (26), whereby an axial movement of the externally toothed gear (26) with respect to the input shaft (16) is restricted.