The Calculation Solutions Of Bending Stresses Of Face Gear Drives Based On Aeronautic Industry Standard

Applied to helicopter's main reducer, face gear drives transmit torque between space intersectional shafts. Compared with bevel gear drives, the face gear drives can offer the following advantages: larger transmission ratio, no preventing dislocation design and no axial force brought to the meshing cylindrical gear. Besides, as the first stage of helicopter's main reducer, face gear drives have the features of high power and revolving speed. Thus, the study on the calculation solutions of the bending stresses of face gear drives has great significance. The research contents mainly consist of the method of equivalent spur gear drives for face gear drives, the calculation solutions of bending stresses of face gear drives based on Aeronautic Industry Standard, the test scheme design, experiment and software development.Combined with the point contact in face gear drives in engineering, extreme inner and outer radiuses and modified coefficients of the extreme radiuses are derived in a piecewise form. Meanwhile, contact radius and contact ratio on face gears are obtained. The influence rules of module, pressure angle, transmission ratio on extreme radius and contact radios are analyzed.Based on Aeronautic Industry Standard HB/Z84, the calculation solutions of bending stresses of face gear drives are studied. In addition, impacts of main geometry parameters on bending stresses on face gear drives are discussed.In accordance with the objective of the experiment, a test scheme of bending stresses of face gear drives is designed. A loading equipment, a date acquisition equipment and a test bridge are selected. Test pieces of face gears and fixture are designed. The stresses and strains of the fixture, face gears and the pressure head are analyzed.The bending stresses of face gear drives are measured in accordance with the studied test procedures and preparatory works of the experiment. The bending stresses of face gear drives are analyzed by FEM method. Through the comparison of the results of bending stresses obtained from experiment, theory and FEM, it shows that the validity and feasibility of the calculation solutions of bending stresses of face gear drives based on Aeronautic Industry Standard.Taking GUI module of MALAB as a platform, framework of the software is designed. Analysis software of face gear drives about bending stresses based on Aeronautic Industry Standard is developed, which provides a convenient tool for the engineering application of face gear drives.