KTR curved tooth coupling is widely used in the transmission system of high-speed trains. Due to its important role in the transmission process, it is necessary to conduct comprehensive and in-depth research on its meshing characteristics, stress conditions, and vibration characteristics. This paper aims to study the KTR curved tooth coupling from the above aspects by combining theoretical calculations with software simulation.
To study the meshing situation of KTR curved tooth coupling, three commonly used calculation methods were first compared and analyzed. Based on the machining principle of drum teeth, a modified geometric algorithm was proposed. The study showed that the modified geometric method improved the calculation accuracy and speed. KTR conducted tooth meshing analysis, drum tooth interference analysis, internal and external tooth motion analysis, and drum tooth surface load calculation on the KTR curved tooth coupling based on the proposed geometric correction algorithm. The following conclusions were drawn from the research:
As the axial inclination angle increases, the tooth surface clearance of each tooth decreases, and the position of small clearance on the tooth surface gradually shifts towards both sides of the tooth surface, with a tendency to transfer from the tooth tip to the tooth root; As the gear teeth rotate from the pure flipping area to the pure swinging area, the position of the small clearance on the tooth surface gradually approaches the center position of the tooth width in the tooth width direction and concentrates towards the tooth tip area.
2. Interference analysis of drum shaped teeth shows that the larger the axial inclination angle, the more severe the interference of tooth surface curvature; The bulging radius of the tooth surface and the tangential displacement of the inner teeth can affect the back contact of the drum shaped teeth.
3. Analysis of the motion of the inner and outer teeth shows that the relative sliding rate of the tooth surface is mainly caused by the relative swing of the inner and outer teeth.
4. The calculation of the load on the drum shaped tooth surface shows that the tooth surface in the pure flipping area is more prone to contact, and the tooth surface force is significantly greater than that of other teeth; The relative tooth surface force coefficient is mainly affected by the axial inclination angle and input shaft torque.
5. Analysis of the additional torque of the coupling shows that the additional torque (including restoring torque and friction torque) increases with the increase of the shaft inclination angle, and its variation pattern is mainly affected by the distribution of contact teeth, while the influence of deflection torque can be ignored. Further optimization analysis was conducted on the drum shaped tooth profile, and it was found through calculations that using a high pressure angle and small modulus tooth profile can effectively improve edge contact and interference.
The study proposed a method of optimizing the tooth surface of any drum curve using an external tooth profile. Subsequently, a multi-body dynamic model of the KTR curved tooth coupling and the high-speed train with KTR curved tooth coupling was established to conduct preliminary vibration characteristics analysis of the coupling under cyclic excitation. Through spectral curve research, it has been shown that the external tooth support reaction force peaks at odd multiples of the excitation frequency, while the internal tooth is subjected to gyroscopic force, resulting in deflection acceleration. The vertical vibration acceleration of the internal tooth increases with the increase of operating speed, and its frequency response is sensitive to rotation.