Reliability is one of the key points in the engine development process, and the reliability of gear system plays an important role in the engine reliability. The gear structure is complex, and the operating conditions are variable. There are many factors that affect the reliability of the gear system. The reliability of gear system is a complex dynamic problem, involving strength, lubrication, connection reliability and other factors. Different factors have different effects on the dynamic characteristics of gear system. When solving problems of gear system and changing relevant parameters, it is often impossible to directly evaluate the impact of various factors on the gear system. Therefore, when designing and optimizing gears and other relevant systems, It is necessary to analyze the influence of different factors on the dynamic characteristics of gear system.
In order to improve the reliability of the transmission gear system of a diesel engine, the dynamic model of the gear and valve system is established by using the software EXCITETimingDrive, and the influence of the factors such as backlash, tooth width and load on the dynamic characteristics of the gear system is analyzed, It provides reference for improving the reliability and optimization design of gear system.
A multi-degree-of-freedom dynamic model of the gear and valve system of a large cylinder diameter diesel engine was established by using the software EXCITETimingDrive. The effects of the factors of backlash, load and tooth width on the dynamic characteristics of the specific gear system were analyzed.
1) The single backlash factor mainly affects the dynamic inter-tooth force, and has no obvious effect on other dynamic characteristics; When the gear strength margin is large, the accuracy of the backlash can be appropriately relaxed, but considering the impact of vibration and noise, the backlash should be reduced as much as possible.
2) The load has a significant impact on the main dynamic characteristics of the whole transmission chain. When lifting the dynamic indicators of the gear system, in addition to the optimization of the gear system itself, the accessories should also be reasonably optimized and matched to reduce the dynamic load and improve the dynamic characteristics of the gear system.
3) The tooth width mainly affects the strength of the gear system. When increasing the tooth width, the increase of the gear quality should be limited to significantly improve the strength; The tooth width has a great influence on the oil film thickness of the gear bushing, but has a small influence on the radial force of the bushing and the oil film thickness of the peripheral gear bushing.