ANSYS STRUCTURAL: Shaft and Bearing Assembly Static Simulation

In this project, we performed a structural simulation of a Shaft and Bearing Assembly in ANSYS Static Structural.

What is a shaft and bearing assembly?

Shafts are rotating machine elements for transmitting power and torque between components, while bearings are the supports that hold the shafts in place, control their loads, and allow them to have free rotation. The shaft-and-bearing assembly is one of the most typical systems in rotating machinery, such as gearboxes, pumps, and conveyors. This assembly consists of a shaft supported at both ends by bearings and two pulleys mounted on the middle region of the shaft, through which belts are driven by the shaft.

Geometry Definition:

We modeled the geometry of the computational domain with Design Modeler software. The computational domain corresponds to a shaft and bearing assembly, consisting of a main horizontal cylindrical shaft with two coaxial pulleys mounted on it and constrained at two ends by the bearings in the housing blocks.

Mesh:

We meshed the computational domain to create a discretized domain. An unstructured grid was created, so that about 205,000 elements were generated.

ANSYS Static Structural:

There are different solvers and software available for users for structural modeling. For the present simulation, we utilize the ANSYS Static Structural Solver. The overall procedure and main steps required for static structural simulations include the definition of materials, connections, different types of boundary conditions, and post-processing.

How to define boundary conditions?

First, we defined a standard Earth gravity boundary condition on the entire body of the shaft-bearing system. This gravity load is applied downward to the entire body of the shaft-bearing system due to the weight of the shaft and the pulleys. Next, we defined a force load boundary condition on the two pulleys mounted on it. This force load is applied tangentially to the pulleys due to the driving pull of the belts. Next, we defined a fixed support boundary condition on the bottom faces of the bearing housings on both sides. This constrained the shaft and bearing assembly from movement, representing the housing bolted down to a rigid frame.

What is the purpose of this simulation?

This investigation aims to evaluate the structural response of the shaft and bearing assembly under loading and study the solid behavior with analysis of distributions of the total deformation, elastic strain, and von Mises stress.

Results and discussions:

The total deformation distribution indicates that maximum deflection occurs in the middle region of the shaft, where the pulleys are mounted. The obtained shaft bend with a deflected shape is a result of the gravity load and belt loads. The stress distribution indicates that the highest stress appears in the regions of the shaft inside the bearings and under the pulley seats. This is a result of the bending moment generated by the transverse loads.