Wheel Speed Reducer Gear Nesting for Torque
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Solution Overview
Problem
Existing wheel driving speed reducers face challenges in maintaining high transmission capacity while maintaining compactness, as they often require larger member sizes which are not feasible in limited radial and axial spaces.
Innovation Solution
The design incorporates a parallel shaft gear mechanism with a protruding tooth portion that extends into a gap between the casing and internal gear, allowing for increased tooth width and transmission torque without increasing the overall size or weight, and includes a brake mechanism that overlaps with the casing to enhance compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the sizes of members are increased to increase transmission torque, then transmission capacity is improved, but the overall size and weight of the speed reducer increase
Solution Approach 1:
The tooth portion of the parallel shaft gear is nested into the gap between the casing and the internal gear, allowing the gear teeth to extend into the available space without increasing the overall external dimensions of the speed reducer. This nesting approach enables increased tooth width and transmission torque while maintaining compact overall size and weight.
Solution Approach 2:
The invention utilizes the axial dimension by allowing the tooth portion to protrude and extend into the gap in the axial direction. When viewed in the radial direction, the tooth portion and internal gear overlap, effectively using three-dimensional space to increase transmission capacity without increasing the radial or axial footprint of the speed reducer.
2Power
If the sizes of members are increased to increase transmission torque, then transmission capacity is improved, but the overall dimensions of the speed reducer increase
Solution Approach 1:
The tooth portion is nested into the gap between the casing and internal gear, allowing the gear structure to utilize the existing axial space without protruding beyond the outer boundaries of the speed reducer. This enables increased tooth width and transmission torque while maintaining the same axial dimension.
Solution Approach 2:
The invention transitions the gear tooth design from a two-dimensional radial expansion to a three-dimensional configuration where teeth extend axially into the gap. This dimensional change allows the tooth width to increase in the axial direction while the overall axial length of the speed reducer remains constrained by the casing boundaries.
3Power
If the tooth width of the parallel shaft gear is increased to increase transmission torque, then transmission capacity is improved, but the radial size of the gear mechanism increases
Solution Approach 1:
The invention changes the orientation of tooth width measurement from the radial direction to the axial direction. By allowing the tooth portion to extend into the gap axially, the effective tooth width increases without increasing the radial footprint of the gear mechanism, thus maintaining compact radial dimensions while improving transmission torque capacity.
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 ensures higher transmission capacity and maintains the compactness of the speed reducer, allowing for increased torque without enlarging the dimensions, while also ensuring low noise and vibration performance through the use of a helical pinion and gear combination.
Implementation Method 1
a parallel shaft gear mechanism that includes a parallel shaft gear, and a planetary gear mechanism that is provided on a rear stage of the parallel shaft gear mechanism and includes planetary gears and an internal gear with which the planetary gears internally mesh
Data Source
Figure 1
Figure 2
AI summary
A wheel driving speed reducer includes a parallel shaft gear mechanism (22) that includes a parallel shaft gear (24,26), a planetary gear mechanism (16) that is provided on a rear stage of the parallel shaft gear mechanism (22) and includes planetary gears (48) and an internal gear (50) with which the planetary gears (48) internally mesh, and a casing (20) that accommodates the parallel shaft gear mechanism (22) and the planetary gear mechanism (16). A tooth portion (26A) of the parallel shaft gear (24) protrudes and extends into a gap (51), which is formed between the casing (20) and the internal gear (50) or a member (53) integrated with the internal gear (50), in an axial direction. The tooth portion (26A) of the parallel shaft gear (22,24,26) and the internal gear (50) or the member (53) integrated with the internal gear (50) overlap each other when seen in a radial direction.