## General Mechanical

#### Is my model correct regarding bearing connections?

• ENV159
Subscriber

The front bearing is modeled as 3 ball bearings and the rear bearings as 2 ball bearings. The stiffness for the front bearing is 293760 N/mm and the rear bearing stiffness is 21600 N/mm. I used equations for triple and double bearing arrangements to calculate overall stiffness. There is a force on the front of the model. For the K11, K22, K12, K21 variables I just input the stiffness values into K11 and K22. I got a deflection which makes sense to me and when I tried to put values into K12 and K21 my model would not run. With K11 and K22 only I get a warning stating "not enough constraints, MAY lead to errors or warnings", my results are shown below. if possible can someone take a look at my file?

Model with Force

Spring Settings: K11 and K22 able to run simulation

Simulation Results: 0.019 mm Deflection

Thank you

• peteroznewman
Subscriber

If you physically have two ball bearings side-by-side at the rear, you should have two Bearing constraints at the rear, one for each surface. You say you have 3 ball bearings at the front, but I only see two surfaces.  There should be three surfaces and three Bearing constraints.

Each Bearing constraint has its own point, and the points will be closer together front-to-rear if you have separate Bearings and not clump adjacent bearings into one Bearing object in Mechanical.

I will read up on the K12 and K21 inputs and reply later or someone else might be able to answer that question.

Regards,
Peter

• ankitdv98
Subscriber

@ENV159 how did you calculated the stiffness of ball bearing?? I have to use deep groove ball bearing [6212] in my Model, can you please share the method or equations.

Thanks

Ankit

• mtcnonn
Subscriber
I have an according situation, Can you help me to solve please:nnI have a situation to find the housing displacements caused by bearing loads. Please see the topic I opened: https://forum.ansys.com/discussion/comment/103285#Comment_103285nnregards;nmtco