2018-28-0027 Published 09 Jul 20 18 © 2018 SAE International. All Rights Reserved.Finite Element Simulation and Validation of Planetary Gear System Sonu Paroche, Himanshu Deshmukh, Suresh Kumar Kandreegula, and Alok Muley VE Commercial Vehicles Ltd Citation: Paroche, S., Deshmukh, H., Kandreegula, S.K., and Muley, A., “Finite Element Simulation and Validation of Planetary Gear System,” SAE Technical Paper 2018-28-0027, 2018, doi:10.4271/2018-28-0027. Abstract The planetary gear system is a critical component in speed reduction of gear system. It consists of a ring gear, set of planetary gears, a sun gear and a carrier. It is mainly used in high speed reduction transmission. More speed variation can be achieved using this system with same number of gears. This speed reduction is based on the number of teeth in each gear. The size of new system is compact. A theoretical calculation is performed at concept level to get the desired reduction of speed. Then the planetary gear system is simulated using ANSYS software for new development transmission system. The final validation is done with the testing of physical parts. This concept is implemented in 9speed transmission system. Similar concept is in development for the hub reduction with planetary gears. The maximum 3.67 reduc - tion is achieved with planetary system. The stresses in each pin is calculated using FEA. Keywords Planetary gear system, FEA, Speed reduction  FIGURE 1   General Representation of a Planetary System© SAE InternationalIntroduction Transmission is one of the essential part of a vehicles. Its act a link between power transmissions from engine to the axle. In recent development of the vehicle, it is highly recommended to design a robust transmission which can transmit the more power with less number of the compo - nents. The torque reduction capacity is the key parameter for any transmission system. The torque reduction can be achieved with the changing the gear teeth ratio. Further speed can be reduced using a different combination of gear pairs. For a compact system a planetary gear system is used for various speed reduction. Figure 1 illustrate the generalize view of the planetary system. The major gain from the plan - etary gear is to divide the torque in various combinations of gear pair. The number of planet gears depends of the output requirements. H. ligata et al. studied hoop strain experi - mental for a 4-pinion planetary gear set having no carrier error [ 1]. Planetary gear system is less costly if it is tooled properly. These systems are usually smaller than the conventional gearbox and having higher reduction ratio and high radial load on output shaft. This makes this system lighter and compact and also the operation is less noisy. So the system is fulfilling the need of light weight construction which is having high load capacity and power density and meeting the expectation of good reliability of gear. Lots of studies has been done to analyze the dynamic behavior of planetary gear set. Parker et al. has done the dynamic study of planetary gear considering a spur gear and bearing clearance involving tooth welding and bearing clearance nonlinearity [2]. Ajit Bodas et  al. presented a state of the art contact mechanics model of planetary gear set to study the effect of a Downloaded from SAE International by University of Michigan, Sunday, August 12, 2018 2 FINITE ELEMENT SIMUL ATION AND VALIDATION OF PLANETARY GEAR SYSTEM © 2018 SAE International. All Rights Reserved. number of manufacturing and assembly related carrier and gear errors on the load sharing amongst the planets [3]. To define speed relationship between the planetary gears is very difficult because planetary gears also rotate about their own axis. The speed reduction can be done with different combination of connection for a planetary system. All combi - nation may not require for this system but some combinations are very useful. A single equation can be derived for all