Pitch-Pivot Connection Test Bench Using Lateral Force Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current test stands for rotor blades are complex and require significant effort to validate pitch slewing rings, as they need to simulate the mechanical properties of the entire rotor blade, which is time-consuming and inefficient.
Innovation Solution
A test stand with a rotor hub adapter and a rotor blade element mounted via a rotary joint, utilizing a lateral force compensation device with a tensionable belt to apply a predetermined ratio of bending moment and lateral force to the slewing ring, allowing for compact structure testing with a shorter rotor blade element that simulates the rotor blade root area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complete rotor blade is used in the test stand, then the mechanical properties of the entire rotor blade are accurately simulated, but the test setup becomes complex and time-consuming
Solution Approach 1:
The rotor blade is segmented into two parts: a rotor blade element (shorter section) and a rotor blade root region. The rotor blade element is mounted on the test stand via a pitch rotary joint, while the rotor blade root region remains stationary and provides support. This segmentation allows accurate simulation of mechanical properties at the critical pitch rotary joint area without requiring the entire rotor blade, thereby reducing setup complexity while maintaining reliability.
2Device complexity
If a shorter rotor blade element is used, then the test stand becomes more compact and easier to set up, but accurately simulating the mechanical properties of the full rotor blade becomes difficult
Solution Approach 1:
A tensionable belt acts as an intermediary element between the rotor blade element and the stationary rotor blade root region. The belt transmits forces and moments from the shorter rotor blade element to the rigid rotor blade root region, enabling the compact test stand to accurately simulate the mechanical properties of the full rotor blade assembly during pitch rotary joint testing.
3Manufacturing precision
If lateral force compensation is implemented, then the bending moment to lateral force ratio is precisely controlled, but the test device complexity increases
Solution Approach 1:
The tensionable belt allows dynamic adjustment of the lateral force compensation by changing the tension parameter. By adjusting the belt tension, the desired bending moment to lateral force ratio is achieved at the pitch rotary joint, providing precise control without requiring complex mechanical compensation mechanisms.
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
Enables efficient testing of slewing rings with reduced effort by distributing forces evenly through the belt, allowing for precise adjustment and simulation of wind loads over the rotor blade's entire length, thereby reducing test duration and complexity.
Implementation Method 1
Using a strap to support the rotor blade element under applied shear forces ensures that the force absorbed by the shear force compensation device is distributed evenly across the strap's support surface, thus preventing damage to the rotor blade element
Implementation Method 2
A lifting device is provided at the end of the rotor blade element extending from the rotor hub adapter. This lifting device acts on the rotor blade to introduce a lateral force into the rotor blade element. The lateral force introduced into the rotor blade element exerts a necessary load/bending moment at the rotary joint for testing purposes.
Implementation Method 3
A shear force compensation device (Qkk device) is provided, which supports the rotor blade element between the rotary joint and the lifting device via a tensionable strap in order to establish a predetermined ratio of bending moment to lateral force at the rotary joint. A shear force is preferably introduced at the rotor blade tip via the lifting device. This shear force is partially compensated by the shear force compensation device and converted into a bending moment that acts on the slewing ring.
Data Source
Figure 1
Figure 2
AI summary
Test rig for a pitch rotary joint, comprising a rotor hub held in a rotor hub adapter, to which a rotor blade element is mounted via a rotary joint, at the end of which extending from the rotor hub adapter a lifting device is attached which can introduce a transverse force into the end of the rotor blade element, wherein a transverse force compensation device (QCC device) between the rotary joint and the lifting device supports the rotor blade element via a tensionable strap in order to establish a predetermined ratio of bending moment and transverse force at the rotary joint.