Intermediate-Speed Shaft Connection Using Rigid Splines
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Solution Overview
Problem
Existing wind turbine generators with flexible splines in the shaft train require specialized lubrication and cooling systems due to floating shifts, increasing complexity and cost, and maintenance is complicated by the need to access bearings from both ends.
Innovation Solution
A rigid connection between the sun shaft and driven shaft using interference splines, combined with rolling bearings on the generator side to absorb floating shifts, eliminating the need for spline lubrication and simplifying the structure while allowing maintenance from a single side.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flexible splines are used to absorb floating shift of the sun shaft, then the floating shift is eliminated and generator operation is ensured, but spline teeth require specialized surface hardening treatment and pressure lubricant cooling systems, increasing structure complexity and cost
Solution Approach 1:
The patent extracts and removes the complex lubrication and cooling systems from the spline connection. By using rigid splines instead of flexible splines, the invention eliminates the need for surface hardening treatment and pressure lubricant cooling systems, thereby removing these disturbing components while maintaining the ability to handle floating shifts through the bearing support structure.
Solution Approach 2:
The patent introduces a bearing support structure as an intermediary element to handle the floating shift absorption function. Instead of relying on flexible spline characteristics, the invention uses rigid splines combined with bearing supports that provide the necessary compliance and floating shift absorption, thereby eliminating the need for complex lubrication and cooling systems.
2Reliability
If flexible splines with clearance are used to absorb floating shift, then the shift is absorbed, but contact surfaces require continuous lubrication and cooling, leading to increased manufacturing cost
Solution Approach 1:
The invention removes the expensive surface hardening treatment and pressure lubricant cooling systems by extracting these functions from the spline connection. The rigid spline design with bearing support eliminates the need for these costly manufacturing processes while maintaining connection stability.
Solution Approach 2:
The patent changes the fundamental parameter of spline flexibility from flexible to rigid. This parameter change transforms the approach to handling floating shifts, moving from absorption through flexible deformation to absorption through bearing-supported rigid connection, thereby eliminating the need for expensive surface treatments and cooling systems.
3Stability of the object's composition
If a bearing for the driven shaft is placed at the end close to the blades to support the shaft, then radial floating is constrained, but maintenance requires access from both ends of the shaft, increasing maintenance difficulty
Solution Approach 1:
The patent extracts the bearing from the blade-side end of the driven shaft and relocates it to the generator-side end. This removal and relocation of the bearing from the difficult-to-access position eliminates the need for two-sided maintenance access while maintaining shaft support functionality through the rigid spline connection and alternative support structure.
Solution Approach 2:
The invention inverts the conventional bearing arrangement by placing the bearing at the generator-side end rather than the blade-side end. This inversion of the bearing position makes maintenance accessible from a single side (generator side) while maintaining the necessary shaft support and stability through the rigid spline and support structure.
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
Reduces structural complexity, lowers manufacturing costs, and simplifies maintenance by eliminating spline lubrication and enabling single-sided access to bearings, thus enhancing operational efficiency and reducing downtime.
Implementation Method 1
the driven shaft bearing is configured as a pair of rolling bearings for absorbing floating shift of the driven shaft
Implementation Method 2
a rigid connection between the sun shaft and driven shaft using interference splines
Data Source
Figure 1~2
Figure 3a~4
AI summary
A wind turbine generator parallel-stage intermediate-speed shaft train connecting structure, wherein a sun shaft and a hollow shaft are connected together by means of rigid connection. A bearing for the hollow shaft is arranged on a box body on one side of a generator. Floating shift of the sun shaft during the operation of the generator is absorbed by the bearing. Because interference splines are used to achieve the rigid connection between the sun shaft and the hollow shaft, there is no need to provide lubrication and cooling for the splines, and the structure has low manufacturing costs and the structure is simple. Further provided is a wind turbine generator parallel-stage intermediate-speed shaft train, having the advantages of simple structure and low maintenance costs.