# Outer Rotor PMSM - analysis **URL:** \ **Category:** General Questions\ **Created:** [August 17, 2025, 6:40am UTC](https://prepomax.discourse.group/t/outer-rotor-pmsm-analysis/2936 "2025-08-17T06:40:16Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [August 17, 2025, 6:40am UTC](https://prepomax.discourse.group/t/outer-rotor-pmsm-analysis/2936/1 "2025-08-17T06:40:16Z")
Dear All, We are working on designing an outer rotor PMSM. Please find the model attached. 1. The outer rotor has three materials ( Ferrite magnet, Silicon steel and outer rotor steel + shaft). 2. We want to run the rotor @ max RMP 10000 and check if everything is ok. 3. Silicon steel will be shrink-fitted inside the outer rotor steel and further it will be bonded with epoxy( gaps). 4. Ferrite magnets are arranged in segments and are bonded to silicon steel with an epoxy. Further the segment gaps between the magnets will be filled with epoxy. 5. The shaft will be supported by bearing on each end. 6. We want to maintain the gap between stator and rotor magnet as 0.250 mm. [Dropbox](https://www.dropbox.com/scl/fi/kdwj7k8l85kvss0xujlca/outer-rotor-al.pmx?rlkey=6hibxuknsiook0sjt6vzy8rl1&st=9n0cxcr9&dl=0) ```auto Please let us know if the model that we have come up with is correct or we are missing something. ``` ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [August 17, 2025, 9:17am UTC](https://prepomax.discourse.group/t/outer-rotor-pmsm-analysis/2936/2 "2025-08-17T09:17:23Z")
It lookks good in general but the mesh is too coarse (especially on the inner magnets and in the thickness direction). Also, you may need contact pairs between the magnets. The gaps are small and they may intersect during the deformation. ---
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [August 18, 2025, 5:28am UTC](https://prepomax.discourse.group/t/outer-rotor-pmsm-analysis/2936/3 "2025-08-18T05:28:25Z")
Thank you. Yes we will enahnce the messing parameters. Is the contact type correct ?. What should be the contact type where we will be using epoxy to bond the magnet with silicon steel and what are the typical properties please?. Further we are expecting outer rotor motor to generate max peak of 25Nm. How to set this property ?. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [August 18, 2025, 8:58am UTC](https://prepomax.discourse.group/t/outer-rotor-pmsm-analysis/2936/4 "2025-08-18T08:58:01Z")
Yes, surface to surface contact is the best choice in most cases. Contact properties in the normal direction are often softened with respect to the default Hard contact. You can find some recommendations here: [Snap-fit contact snagging problem - #17 by JuanP74 - CalculiX (official versions are on www.calculix.de, the official GitHub repository is at https://github.com/Dhondtguido/CalculiX).](https://calculix.discourse.group/t/snap-fit-contact-snagging-problem/2277/17) > [@design](#): > > Further we are expecting outer rotor motor to generate max peak of 25Nm. How to set this property ?. Do you mean that you want to apply such torque to one part ? You could use a rigid body constraint for that: [https://www.youtube.com/watch?v=2upPxL45OZg](https://www.youtube.com/watch?v=2upPxL45OZg) ---
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [August 18, 2025, 9:25am UTC](https://prepomax.discourse.group/t/outer-rotor-pmsm-analysis/2936/5 "2025-08-18T09:25:31Z")
As torque will be generated on magnets, we want to apply 25Nm on the magnets uniformly to get an understanding if the rotor will with stand it. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [August 18, 2025, 9:30am UTC](https://prepomax.discourse.group/t/outer-rotor-pmsm-analysis/2936/6 "2025-08-18T09:30:18Z")
Then rigid body constraint will be appropriate. Like in your older case with gears: [Request for steps or procedure to simulate meshed spur/helical gears various static and dynamic analysis - #19 by FEAnalyst](https://prepomax.discourse.group/t/request-for-steps-or-procedure-to-simulate-meshed-spur-helical-gears-various-static-and-dynamic-analysis/487/19)