Transient structural analysis on a Worm Gear assembly.

TITLE: Performance of Transient structural analysis on a worm gear assembly.

SUMMARY: In this project, we simulate a transient structural analysis on a Worm-Gear assembly. A full size Worm is allowed to rotate a Half size of Gear. The both assembly is provided with necessary contacts, connections as well as joint loads in order to simulation went through. Meanwhile, the desired parameters and their values are obtained Respectfully.

INTRODUCTION: In order to perform a transient structural analysis on a worm gear assembly, firstly we consider a simple geometric CAD model. The model is such that, the worm rotates a half size of Gear. The Contact defination between the worm and gear is defined as Frictionless, which means the worm tends to rotate the gear with any friction effect in between them. The model is also provided with necessary revolute joints to entire Worm-Gear assembly, so that the revolution among them can be pursue. Both the Worm & Gear rotates along the Z-Axis.

CAD Model of Worm Gear Assembly.

Following are the Contacts as well as the Joints for Worm Gear assembly. The Red portion in worm indicates the contact surface, while blue refers to the multiple target surfaces.

Once we applied the necessary conditions, the model is ready for pre-processing of simulation. We meshed the model using Default mesh setting with its smoothing quality to Medium. The Meshed model can be seen below.

Meshed Model.

Further, the Analysis settings are carried out. In order to carried out a sucessfull simulation in such a way that the worm should almost touches the far ends of gear the Analysis is set up for 55 steps, with weak springs Program controlled. Similarly joint load is also applied for body to ground Worm, it is described to rotates at 50 Deg. angle at each step. However, for 55 steps the Worm gonna rotate for 55 Deg to almost 2750 Deg for a total of 55 Steps.

Joint Loads for Worm. ( 50 Deg at each step)

Now, the simulation is ready to went through. The desired result to be generated are listed such as Stress, Strain and Deformation, Later they are Evaluated.

• Equivalent Elastic Stress:

The Worm-Gear assembly undergoes a Max. of 1025.1MPa of Stress near the contact surface itself.

Above fig. shows the exact area where, the maximum stress had been occured. It shows that, the region where there is initial contact between worm and gear has more stress induced.

• Equivalent Strain:

Here, a Max. of 0.0059644mm/mm of strain is occured.

• Total Deformation:

Above fig, illustrate that the model undergoes 25.652mm of Total Deformation.

Contact status can be seen below,

Contact status

Meanwhile, Force convergence Graph is also plotted for first initial 30 points of Worm-Gear simulation.

Force convergence Graph

Similarly, Time Increment Graph.

Time Increment Graph

RESULT:

All (Max. & Min.) Generated values of Equivalent Stress, Equivalent Strain and Total Deformation are mentioned below.

CONCLUSION:

1. The Simulation went through, and the worm almost touches end part of gear.
2. The Stress and Strain appears on the sliding area of assembly.
3. High stress is generated on teeth-slot areas of Worm Gear.