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Modeling Motion Eccentricity in ANSYS Maxwell

Eccentricity modeling is crucial in Maxwell 2D and 3D transient designs for simulating imperfections in motor assembly and operational alignments. By using the Maxwell Eccentricity Wizard in ANSYS Electronics Desktop, engineers can evaluate the effects of misalignment, such as variations in the air gap and magnetic fields, which are vital for optimizing motor efficiency and longevity. This tool offers two essential settings: rotating part eccentricity and rotation axis eccentricity, streamlining the simulation of real-world motor dynamics.

Eccentricity Types

  1. Rotating Part Eccentricity: Applies exclusively to rotating objects within a specified band, excluding the band itself.

  2. Rotation Axis Eccentricity: Impacts only the motion axis, effectively moving the band, but not the rotating objects within.

These settings allow for the modeling of different eccentricity types:

  • Static Eccentricity: Both eccentricities are set to identical values.
  • Dynamic Eccentricity: Only rotating part eccentricity is adjusted.
  • Mixed Eccentricity: Both eccentricities are set, but to different values.





Using the Maxwell Eccentricity Wizard

Note: The ACT Extensions and the design wizards are available only on the Windows version of the Ansys Electronics Desktop.

Step-by-Step Guide

  1. Accessing the Wizard:

    • Navigate to View > ACT Extensions to open the ACT Extensions window.
    • Click the Wizards button, then select Maxwell Eccentricity to initiate the setup page
  2. Selecting the Project and Design:

    • Choose the appropriate Project and Design to apply eccentricity settings.
    • Use the Update button to synchronize the selections with those loaded in the Desktop.
    • To exit without changes, click Exit Wizard.
  3. Configuring Eccentricity:

    • For 2D designs: Input dx and dy translation values to define both types of eccentricity.
    • For 3D designs: Enter dx, dy, and dz values, along with offset and tilting angles for the eccentricity axes.
  4. Finalizing the Setup:

    • Click Finish to apply the settings. This will create a new design within the same project with updated Maxwell geometry based on the specified eccentricity values.

Outcomes of Eccentricity Setup

  • For 2D Designs:

    • Variables such as _Eccentricity_translation_of_moving_parts and _Eccentricity_translation_of_rotating_axis are defined.
    • The moving parts and the band are adjusted according to the specified translations.
  • For 3D Designs:

    • Additional variables like _Eccentricity_offset_angle_of_moving_parts and _Eccentricity_tilting_angle_of_moving_parts are utilized.
    • Both the moving parts and the band undergo rotations and translations as defined.

Note: New coordinate systems (e.g., _Eccentricity_moving_part_CS_<part name>) are generated for each part, and existing systems are updated to reflect the new orientations and positions.


  • Modifying Design Variables: These variables can be adjusted to refine eccentricity settings post-setup.
  • Manual Changes: Direct manual modifications to the newly added coordinate systems are not advised.
  • Revising Setups: Avoid using the wizard to modify designs that have already been configured for eccentricity.

Important: After completing the eccentricity setup and clicking Finish, all design geometries are updated to new positions reflective of the applied settings. Any geometric modifications should be made in the original design before re-applying eccentricity settings for a new design iterations.


Modeling motion eccentricity correctly is vital for the accuracy and reliability of simulations involving cylindrical rotational motions in ANSYS Maxwell. The Maxwell Eccentricity Wizard simplifies this process, ensuring precise and effective application of eccentricity to enhance simulation realism and outcomes.

Post by Ian Chavez
April 23, 2024