Axle Assembly Internal Bevel Gear Reduction
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Solution Overview
Problem
Existing axle assemblies with differential gear systems often require external planetary gear sets for gear reduction, which increase cost, weight, and complexity, while offering limited flexibility in gear ratios and speed reduction.
Innovation Solution
The integration of a bevel gear reduction unit within the differential assembly, which allows for internal gear reduction and eliminates the need for external planetary gear sets, providing a more flexible and efficient means of achieving various gear ratios through adjustable spider pins and tooth configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If external planetary gear sets are used for gear reduction, then gear reduction is achieved, but cost, weight, and complexity increase
Solution Approach 1:
The patent combines the gear reduction unit with the differential assembly into a single integrated structure. The bevel gear reduction unit is positioned within the differential housing, sharing common components such as the case, seals, and lubrication system. This merging eliminates the need for separate external planetary gear sets, thereby reducing overall system complexity while maintaining reliable gear reduction functionality.
Solution Approach 2:
The bevel gear reduction unit is nested within the differential assembly structure. The reduction unit's gears and components are contained inside the differential housing, utilizing the existing spatial envelope. This nesting approach allows the gear reduction function to be embedded within the differential structure, reducing the number of external components and simplifying the overall system architecture.
2Device complexity
If external planetary gear sets are used, then gear reduction is provided, but weight increases
Solution Approach 1:
By merging the gear reduction unit with the differential assembly, the patent eliminates redundant structural components. The integrated design shares common housing, mounting structures, and support elements between the differential and reduction unit, thereby reducing the total weight compared to separate external planetary gear sets.
Solution Approach 2:
The patent extracts the gear reduction function from external planetary gear sets and relocates it within the differential assembly using a compact bevel gear configuration. This extraction removes the heavy external gear housing and support structures, retaining only the essential reduction gears within the existing differential structure, thus reducing overall weight.
3Device complexity
If external planetary gear sets are used, then gear reduction is achieved, but the range of achievable gear ratios is limited
Solution Approach 1:
The patent employs adjustable spider pins within the bevel gear reduction unit that can be repositioned to change the effective gear ratio. This dynamic adjustment capability allows the same physical structure to provide multiple gear ratios, enhancing versatility without increasing structural complexity. The adjustable mechanism enables adaptation to different operational requirements while maintaining a simple integrated design.
4Device complexity
If external planetary gear sets are used, then gear reduction is provided, but cost increases
Solution Approach 1:
The integration of the gear reduction unit with the differential assembly reduces the total number of parts that need to be manufactured, assembled, and sealed. The combined structure requires fewer gaskets, fewer fasteners, and fewer alignment procedures during assembly, thereby reducing manufacturing complexity and associated costs compared to separate external planetary gear sets.
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 solution reduces the cost, weight, and complexity of the axle assembly by enabling internal gear reduction, expanding the range of achievable gear ratios and improving speed reduction efficiency, while allowing for more compact and adaptable designs.
Implementation Method 1
a bevel gear reduction unit (84) integrated within the differential assembly (24), said bevel gear reduction unit (84) including a first side gear (112), a second side gear (162), and a spider (160) operatively connecting said first side gear (112) and said second side gear (162)
Data Source
Figure 1
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AI summary
An axle assembly having a differential assembly that may include a gear reduction unit, a differential nest, and a coupling. The differential nest may be at least partially received in an inner housing. The inner housing may be rotatable about an axis with respect to an outer housing when the coupling is in a first position. The inner housing may be rotatable about the axis with the outer housing when the coupling is in a second position.