大型遙控直升機主旋翼主軸承螺栓受力分析

本文研究重點為旋翼型式的大型遙控直升機，由於旋翼型式的UAV(Unmanned Aerial Vehicle)具備垂直起降，低速空中懸停等優點，非常適合從事商用無人飛行載具之用途。隨著無人自主直升機發展的進步，建置於直升機之系統功能也越來越複雜，使得研發成本也相對增高。然而，直升機在飛行時所遭遇的外在氣動力干擾相當複雜，當轉速不穩定時將會影響主旋翼所產生的升力，輕則使得直升機姿態未達到預期的目標，重則使旋翼葉片(Rotor Blade)無法承受高速旋轉與載重產生脫離及斷裂極度危險的環境。因此，為了提高無人直升機飛行的安全與穩定，我們便針對旋翼轉速與旋翼葉片離心力加以研究討論，並計算其所受的推力及離心力進行螺栓強度分析。也因考慮其結構的安全性。在傳統的設計多是依賴實驗測試，不斷的修正改進，達到目標為止，這樣的做法使得設計開發時程拉長，設計成本無法降低，也可能無法達到設計的最佳化。為了簡化無人直升機的控制方式本文所採用Bell 206，Bell 407兩種直升機模型，並在各模型之間分別採用單、雙鉸接，並比較兩種鉸接型態進行螺栓受力分析。所採用方法與工具為利用先進的參數化設計軟體(PTC Creo)進行建模並精準的在三維空間建立主旋翼模型結構。採用計算結構力學(ANSYS )建立非結構性網格，採多方向對旋翼葉片進行多方面施加推力與離心力，更精確進行螺栓受葉片旋轉時的細部的計算分析剪力、應力、應變，有助於提升遙控直升機飛行時的保障和安全。

關鍵字

鉸接(Hinge) ； UAV(Unmanned Aerial Vehicle) ；主旋翼(Main Rotor) ；應力(Stress) ；應變(Strain) ；剪應力(Shear Stress)

並列摘要

This paper focuses on the large-scale remote control helicopter with Rotor type. Due to the Rotor type UAV (Unmanned Aircraft System) has the advantages of vertical take-off and landing, low-speed air hovering, and it is very suitable for commercial drone. With the development of helicopters drone, the functions of systems built in helicopters are becoming more and more complex, and the cost of research and development is relatively higher. However, the external aerodynamic interference encountered by the helicopter during flight is complicated. When the speed is unstable, the lift generated by the main Rotor will be affected; therefore, causing it not being able to reach at the desired objectives. Also the Rotor blades are unable to resist a higher speed rotation when the weight exceeds the limits. It will detach or fracture and will cause an incident. Therefore, in order to improve the safety and stability of drone, we have studied and discussed the Rotor speed and Rotor blade centrifugal force, and will calculate the thrust and centrifugal force to analyze the bolt strength. Also consider the safety of its structure. In the traditional design, it relies on experimental testing and continuous improvement, so at the end we can achieves the goal. This approach shows that it will take a longer time to design the concept meaning the design cost cannot be reduced, and the design optimization cannot be achieved. In order to simplify the control method of helicopters drone, the two models of Bell 206 and Bell 407 are used in this paper. Single and double hinges are used between the models, and the two types of joints models are compared for bolt force analysis. By using (PTC Creo) software we can build the main Rotor model structure in 3D. With (ANSYS) is used to establish the non-structural mesh. Thrust and centrifugal force are applied to the Rotor blades in multiple directions. More precise details of the calculation time of the rotary blade shear, stress and strain. And helps improve the safety of the drone during flight time.