Week 8 Worm Gear Challenge

Introduction:

A worm gear (or worm drive) is a specific gear composition in which a screw (worm) meshes with a gear/wheel similar to a spur gear. The set-up allows the user to determine rotational speed and also allows for higher torque to be transmitted. This mechanism can be found in devices both at home and in heavy machinery; the simplest form evident in the tuning mechanism of an acoustic guitar.

Objective:

To perform a transient structural analysis on a worm gear assembly and get results for Equivalent stress, Equivalent elastic strain and the total deformation.

Procedure:

* Open ANSYS Work bench, from the analysis systems drop the Transient structural in Project schematic.

* Select required material from materials tab, In our case we need Structural Steel only (Default).

* Import Geometry and open in design moduler to check the geometry. Open in Mechanical module and rename the parts (if required) for easy identification purpose.

Note: To run in the acadamic version, Gear wheel cutted half and run the simulation on half gear only.

* In the Connections under project schematic, defaults keeps as usual and add gear teeth also under contact bodies.

* Insert two revolute joints as Body-ground, first joint is gear inside cylindrical surface, and second joint is worm inside cylindrical surfaces, and make sure that both reference coordinates are same, in our case is in Z-axis.

* Default mesh can be generated with adoptive sizing for both worm and gear, as shown below.

* Analysis settings:

No.of steps: 15,

For step1-Auto time stepping: ON, ITS: 2s, Min.TS: 2s, Max.TS: 5s.

Large deflection: On,

Weak springs: Program controlled.

For Step 2 to 15- Auto time stepping: ON, Carry over time step: ON, Min.TS: 2s, Max.TS: 5s.

Large deflection: On,

Weak springs: Program controlled.

* Insert joint load under transient structural, and select worm gear for rotation. Enter tabular date from 0 to 750 degrees ith 50 degress of intervels.

* Insert required output results under solution, in our case we are finding Equivalent stress, Equivalent strain, Total deformation and hit the solve button to run the simulation.

Results:

Total Deformation:7.2775mm max

Equivalent stress: 1824 MPa max

Eqiuivalent strain: 0.0098795 mm/mm

conclusion: Simulation and finding out the results for given model done sucessfully.