Observed failure mode
Installed problem statement
Repeated curb-strike reversals and drag variation overloaded the bearing support path because local housing flex amplified radial load instead of distributing it.
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Bearing support review summary
Wheel-end traction drive with shock reversals, seal drag, and housing deflection
Engineering response
Corrective design move
Support span and wall distribution around the bearing pocket were revised, and incoming plus end-of-line inspection gates were added for seat geometry and drag signature.
Review inputs
Peak curb-strike or reversal events alongside steady-state drive loads.
Bearing-seat measurements, preload targets, and seal-drag observations.
Housing support-span geometry with frame-side reaction path assumptions.
Expected outputs
Nominal versus impact load-path review for the wheel-end module.
Inspection gates for seat geometry and end-of-line torque signature.
Support-span revisions tied to durability and closed-loop response.
Engineering interventions
Mapped the shock path separately from the nominal drive path to identify where peak energy bypassed the intended compliance stage.
Changed the support span and wall distribution around the bearing pocket so radial load was not being amplified by local housing flex.
Added inspection gates on the bearing-seat geometry and end-of-line torque signature so problematic modules were screened before vehicle integration.
Critical watch items
Secondary shock paths that bypass intended compliance stages.
Bearing seats drifting outside repeatable preload conditions.
Seal drag masking structural variation during bring-up.
| Review dimension | Observed result |
|---|---|
| Primary failure mode | Shock load bypassing intended compliance route |
| Critical change | Housing support-span revision and inspection gate definition |
| Production effect | Lower module-to-module variation in drag and preload feel |
Design lessons
Impact durability depends on the true secondary path, not only the nominal torque path shown in concept sketches.
Inspection strategy is part of actuator design when bearing seats and seal friction meaningfully alter system behavior.
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