Lead screws should be sized to operate at or below 80% of the critical speed. Critical speed is the lowest rotational speed at which the screw shaft is in resonance.
Several factors help to determine critical speed including:
- Screw diameter
- Length between bearing supports
- Type of bearing supports used
Lead screws should be loaded in axial compression to levels below their maximum column loading. Exceeding the maximum column loading can result in instability due to screw bending or buckling. These charts limit the screw slenderness ratios based on the type of screw support selected.
Please note that the PV limit of the nut is dependent on the duty of the application and other factors so these curves are a guideline. If your application will operate near or beyond the shown curves, please contact PBC Linear for support.