The objective of this term project was to create and analyze a differential planetary gear transmission system. The gears’ involute profile was calculated through MATLAB scripts for both internal and external configurations. Using SolidWorks and the calculated gear involute profiles, the gears were modeled and assembled. The gear models were saved and imported into ADAMS View to analyze the gear transmission system. Three cases were analyzed with the gear transmission system, a fixed ring gear, a fixed sun gear and no restraints to any of the gears. Theoretical calculations were applied with the use of MATLAB to ensure the accuracy of the ADAMS simulation results, specifically for the carrier speed.
To begin the modeling of the gars, the involute profile of the gear teeth is needed for each gear. The desired constant pressure angle between gear teeth is 20 degrees. The profile is calculated using a MATLAB Script that saves a text file that specifies the coordinates of the involute profile as well as the radii of the base, addendum, dedendum and pitch circles.
Using the text files provided through the MATLAB Scripts, I modeled each gear in Solidworks independently. After modeling each gear, I assembled the gears through SOLIDWORKS Assembly and ensured the gears perfectly meshed. The gears were mated using gear mates and I analyzed the model to make sure meshing interference wasn't present.
Before importing the SOLIDWORKS models into ADAMS, the coordinates of the models in the SOLIDWORKS Assembly were noted and used to create markers in ADAMS. After importing the models into ADAMS, joints and contact forces needed to be applied between each of the gears.
To observe the different dynamics of the planetary gear system, I analyzed three different cases. For each of the three cases there was only one motion applied (one input speed).
For the case with no fixed gears, a motion of 750rpm was input into the Z1 Gear (Blue Gear). In the final report, I analyzed the carrier's (Light Blue Fixture) rotational speed measured through ADAMS compared to the theoretical value calculated in MATLAB. The ADAMS Simulation showed a relatively stable velocity arounf 600 deg/sec.
For the case with a fixed ring gear (Green Gear), a motion of 750rpm was applied to the sun gear (Small Grey Gear). Shown in the final report, the angular velocity of the carrier was highly variable, oscillating just below 1000deg/s. This is most likely due to poor meshing of the gears, caused by tuning after errors occured during the simulations. Although there are oscillations, the oscillations are centered around the theoretical value 957.5 deg/s.
For the case with a fixed sun gear (Small Grey Gear), a motion of 750rpm was applied to the Z1 gear (Blue Gear). Shown in the final report, the angular velocity of the carrier was highly variable, oscillating around 1100deg/s.This is most likely due to poor meshing of the gears, caused by tuning after errors occured during the simulations. Although there are oscillations, the oscillations are centered around the theoretical value 1060.2 deg/s.