The following table summarizes the transfer paths of electromagnetically-excited vibrations in electric machines. Most common e-NVH issues arise due to transfer paths 1 & 2.
| ID | Circumferential wavenumber | Force direction | Nature | Transfer path analysis |
| 1 | r>1 | Radial, tangential | Air-borne | Radial circumferential deflection of the outer stator yoke and frame assembly, or of outer rotor (rotating in forced regime, pulsating at resonance). |
| 2 | r=0 | Radial | Air-borne | Radial pulsating circumferential deflection of the outer stator lamination and housing assembly, or of outer rotor. |
| 3 | r=1 | Radial (unbalance magnetic pull) | Air-borne | Bending / tilting deflection of the outer stator frame or outer rotor, in particular in clamped-free conditions and with eccentricities. |
| 4 | r=1 | Radial (unbalance magnetic pull) | Structure-borne | Propagation of rotor bending vibration to rotor shaft line and gearbox mount, or bearing sleeves and outer stator frame. |
| 5 | r=0 | Tangential (cogging torque / torque ripple) | Structure-borne | Propagation of rotor torsional vibration to rotor shaft line and gearbox mount, or bearing sleeves and outer stator frame. |
| 6 | r=0 | Tangential (cogging torque / torque ripple) | Air-borne | Deflection of the outer stator yoke and frame or outer rotor following a unbalanced torsional mode due to particular boundary conditions. |
| 7 | r=0 | Axial | Air-borne | Axial deflections of the end shields, especially when axial magnetic force harmonics occur due to skewing. |
- Transfer Path Analysis of electromagnetic noise & vibrations