Spline Shaft Failure
Spline shafts are used to transfer rotational motion for linear distances. They are used in a varitey of industrial and transportation applications. They are manufactured by broaching machines.
In this case, a large electric motor experienced a catastrophic failure of a spline shaft.
The fracture surface was removed and evaluated by stereo microscopy followed by scanning electron microscopy (SEM).
The failure was traced to abrasive wear caused by fretting of the splines.
Once wear had become great enough to allow free play, the splines began to break away under the initial starting loads, each time the electric motor was initiated.
The root cause of failure was determined to be the improper fit of the components during the original manufacture and assembly.
Touchstone performs this kind of failure evaluation daily at its laboratories.
In fact, Touchstone has performed thousands of failure investigations for machine shops, steel companies, aluminium companies and automotive parts manufacturers.
Should you need to determine the cause of failure of a part, or system of parts, please contact us.
Failure Analysis Examples
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