Spindle Shaft

(Difference between revisions)

Revision as of 21:04, 12 April 2007

Developed a model to predict the peak cutting force and shaft torque
Wrote a matlab tool (edited version below) to determine peak forces and bending moments in spindle shaft and bearings
Wrote a matlab tool to specify bearing from cutting force, torque, and desired life and reliability (via the Weibull Equation)
Specified a collet from sheets provided in lab
Used results from above tools and supplied lathe solid model to specify shaft dimensions:
- 30 mm shaft outer diameter, 50mm diameter for center section
- 10 mm inner diameter

Altered matlab tool to take into account fatigue at bearing A.
For a steel shaft, we have a slope factor of safety of 9, a stress factor of safety of 15. The stresses are an order of magnitude below the endurance limit, so fatigue should not occur anywhere in this shaft. (or, a lifetime of 10^10 minutes - about right according to Chris).
Assumptions - w_shaft = 570rpm, axial force = 100N, radial force = 240N, stress concentration at fillet = 2.5.

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 * Altered [http://web.mit.edu/mmcbrien/Public/2-72/Spindle/shaft_stress_slope_fatigue.m matlab tool] to take into account fatigue at bearing A.
-* For a steel shaft, we have a slope factor of safety of 9, a stress factor of safety of 15, and a fatigue lifetime of 10^10 minutes (this lifetime is about right according to Chris).
+* For a steel shaft, we have a slope factor of safety of 9, a stress factor of safety of 15. The stresses are an order of magnitude below the endurance limit, so fatigue should not occur anywhere in this shaft. (or, a lifetime of 10^10 minutes - about right according to Chris).
 * Assumptions - w_shaft = 570rpm, axial force = 100N, radial force = 240N, stress concentration at fillet = 2.5.