Transient Structural Analysis on a Worm Gear

Aim:

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

Case setup:

1.Material Selection.

In material, Structural steel is by default applied to all bodies that are

• Worm gear
• worm wheel

2.Geometry:

An assembly of meshed worm and gear is directly imported in the workbench from available sources. To keep the mesh elements within academic limits worm wheel is cut symmetrically into half parts and only on the part is simulated in the following simulation.

Geometry showing worm gear and worm wheel:

3.Meshing:

Programme controlled mesh with a mesh element size of 2mm is used in the following simulation

However, regions of particular interest i.e contacting surface between the worm gear and worm wheel mesh with a mesh element size of 2 mm.

The meshed model image and mesh metric graph can be seen below:

The mesh metric is utilized to identify the elements according to their quality using skewness. The quality of the mesh is acceptable as most of the elements lie within a high-quality range.

4.Setup:

Revolute joint assigned to worm wheel:

Revolute joint assigned to worm Gear:

The revolute joint is assigned to both the worm wheel and worm gear about the axis of their rotation

Contacts:

Frictionless contact between the gear teeth interface.

Frictionless contact is established between the worm wheel and worm teeth interface

Boundary conditions:

Rotation as the boundary condition:

Joint rotation is provided as a boundary condition to the worm gear. Here time-dependent rotation is given to the component at a rate of 80 degrees/sec. for 25 time steps seconds.

Results:

Total deformation:

The peak Magnitude of total deformation is 19.01mm.

Animation for the total deformation:

Equivalent Elastic strain:

The peak Magnitude of the Equivalent elastic strain is 0.0095 mm/mm.

Animation for the Equivalent Elastic strain:

Equivalent stress:

The peak Magnitude of the Equivalent Stress is 1867 Mpa.

Animation for the Equivalent Stress:

Conclusion:

Results show the development

• Total deformation of about 19 mm is seen in the following simulation when the worm gear is rotated to about 2000 degrees angle about its axis of rotation.
• The high equivalent stresses in the worm gear model and also it is varying almost periodically fluctuating from 1867-3118 Mpa.
• The high Equivalent Elastic strain in the worm gear model and also it is varying almost periodically fluctuating from 0.0095 - 0.0186 mm/mm.