Planetary Gear Shaft Structure for Misalignment Compensation
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Solution Overview
Problem
The existing planetary gearsets in turbomachines face issues with misalignment due to high torque transmission, leading to performance degradation and premature wear of teeth, which is exacerbated by the use of additional shims that increase complexity, cost, and mass.
Innovation Solution
A planetary gearset design featuring pinion gear shafts with radially inner and outer cylindrical portions connected by a flange, allowing controlled deformation to compensate for pinion gear carrier deformations, maintaining meshing performance and preventing premature wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If additional shims are arranged between pinion gears to take up forces and keep sun gear shafts parallel, then misalignment is avoided, but device complexity, cost and mass increase
Solution Approach 1:
The patent removes the additional shims from the system by integrating the alignment compensation function directly into the pinion gear shaft structure. The shaft's flexible connecting zone absorbs the deformations that previously required external shims, thereby eliminating unnecessary components while maintaining alignment precision.
Solution Approach 2:
The patent combines the functions of the pinion gear shaft and the alignment compensation mechanism into a single integrated structure. The flexible connecting zone of the shaft serves both as a structural support element and as the means for absorbing carrier deformations, eliminating the need for separate shims and reducing overall system complexity.
2Manufacturing precision
If additional shims are arranged between pinion gears to take up forces and keep sun gear shafts parallel, then misalignment is avoided, but cost increases
Solution Approach 1:
The patent eliminates the need for additional shims by integrating the alignment compensation function into the pinion gear shaft structure. This removal of components directly reduces material costs, assembly costs, and maintenance costs while maintaining the required alignment precision through the shaft's inherent flexibility.
3Manufacturing precision
If additional shims are arranged between pinion gears to take up forces and keep sun gear shafts parallel, then misalignment is avoided, but mass increases
Solution Approach 1:
The patent removes the additional shims from the gearset, thereby reducing the total mass. The alignment precision is maintained not by adding mass in the form of shims, but by redistributing the structural flexibility into the pinion gear shaft's connecting zone, achieving weight reduction without sacrificing precision.
4Power
If high torque is transmitted through the planetary gearset train, then power transmission is achieved, but pinion gear carrier deforms causing misalignment
Solution Approach 1:
The patent introduces dynamic flexibility into the pinion gear shaft through the connecting zone, allowing the shaft to adapt its shape in response to torque-induced carrier deformations. This dynamic adjustment maintains proper meshing alignment under varying load conditions, unlike rigid shafts that would become misaligned under high torque.
Solution Approach 2:
The patent changes the stiffness parameter of the pinion gear shaft by creating a flexible connecting zone with reduced rigidity. This parameter change allows the shaft to deform in a controlled manner, compensating for carrier deformations and maintaining alignment precision even when high torque causes the carrier to distort.
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 effectively compensates for deformations, maintaining good meshing performance and preventing premature wear of teeth while reducing complexity and cost by allowing controlled deformation of the shafts and pinion gear carrier.
Implementation Method 1
such a structure allows a controlled deformation of the shaft at the flange, cylindrical parts or connection area to compensate for the deformations of the pinion gear carrier
Data Source
AI summary
A planetary gearset having a first planet gear, a second planet gear, and pinion gears. The pinion gears mesh with the first planet gear and with the second planet gear, and each pinion gear is pivotally mounted around a shaft. A pinion gear carrier supports each shaft. Each shaft has a radially inner cylindrical portion mounted on the pinion gear carrier, a radially outer cylindrical portion about which the pinion gear is pivotally mounted and a flange extending radially from the radially outer cylindrical portion. The radially outer periphery of the flange is mounted on the pinion gear carrier. The radially outer cylindrical portion and the radially inner cylindrical portion are connected to each other by a radially extending connecting zone.