Planet Carrier Bearing Layout for Modular Two-Stage Planetary Gears
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Solution Overview
Problem
Conventional planetary gears used in wind turbines have a large number of components, complex and expensive bearings, and are difficult to assemble and maintain, necessitating a high-performance, modular, and cost-effective solution.
Innovation Solution
A planetary gear design featuring two gear stages mechanically coupled with a differential housing, using a minimum number of bearings that can absorb axial and radial forces, allowing for easy assembly and maintenance, and incorporating preloaded tapered roller bearings for adjustable assembly and a modular structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional planetary gearboxes use multiple bearings to support planet carriers on both sides, then the bearing arrangement provides good centering and stability, but the number of components increases and assembly becomes more complex
Solution Approach 1:
The patent removes one bearing from each planet carrier support, transitioning from two-sided bearing support to one-sided bearing support. This extraction of unnecessary components reduces the total bearing count while maintaining functional requirements through the differential housing design.
Solution Approach 2:
The differential housing design allows the single bearing to perform multiple functions: supporting the planet carrier, enabling differential motion between gear stages, and providing automatic centering. The housing itself becomes a multi-functional element that compensates for the reduced bearing support.
2Device complexity
If conventional planetary gearboxes use standard bearings, then the bearing arrangement is simple, but the bearings are complex to adjust and costly
Solution Approach 1:
The bearings are preloaded during assembly, which eliminates the need for complex post-assembly adjustments. This preliminary action of preloading the bearings ensures proper clearance and fit from the start, simplifying the overall manufacturing and assembly process.
3Strength
If conventional planetary gearboxes are designed as integrated units, then the structure is robust, but the gearbox is difficult to transport and assemble at installation sites
Solution Approach 1:
The planetary gearbox is divided into modular gear stages that can be manufactured separately and transported independently. Each module maintains its structural integrity while allowing for simplified on-site assembly, resolving the contradiction between robustness and assembly ease.
4Force
If conventional planetary gearboxes use a large number of components, then the design can accommodate complex load requirements, but the gearbox becomes costly and maintenance-intensive
Solution Approach 1:
Multiple functional elements are merged into fewer components. The differential housing combines support, centering, and motion differentiation functions that would traditionally require separate bearings and support structures. This merging maintains load-bearing capacity while reducing component count.
Solution Approach 2:
The single bearing and differential housing design performs multiple functions simultaneously: supporting planetary carriers, enabling differential rotation between stages, and providing automatic centering. This multi-functionality reduces the number of components needed to handle complex load requirements.
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
The design achieves precise and resilient mounting of planet carriers with minimal bearings, simplifies assembly, reduces maintenance needs, and enhances modularity, resulting in a cost-effective and efficient planetary gear system for wind turbines.
Implementation Method 1
The bearing for the first shaft is designed to absorb axial and radial forces
Implementation Method 2
A rolling bearing is particularly preferred if it is designed as a tapered roller bearing
Data Source
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AI summary
The invention relates to a planetary gear (10) with a first and a second gear stage (20, 30), comprising a housing (12) and a first shaft (16) which is connected in the first gear stage (20) to a first planet carrier (22) in a torque-transmitting manner, wherein the first shaft (16) is received in a bearing (17) on a wall (14) of the housing (12), and the second gear stage (30) comprises a second planet carrier (32) which is connected to a sun shaft (21) of the first gear stage (20) in a torque-transmitting manner, characterized in that the second planet carrier (32) is received in an axially inner bearing (42) which is arranged on the first planet carrier (22) and/or is received in an axially outer bearing (44) which is received in the wall (14) of the housing (12).