Lead screw calculator for force, torque, efficiency and self-locking calculations of ACME lead screws.
A Lead screw (or Power screw) is a device which converts rotational motion to a linear motion and transmits power. Square, Acme and Buttress thread forms are generally used as lead screws.
Common applications are lead screw of lathes, screw presses, screw type of jacks and micrometer screw.
There is a large contact area between male and female threads in lead screws and
this results large frictional loss during the operation. Due to these frictional losses, lead screws are not very efficient
but generally self-locking. In self locking lead screws, the load can’t lower itself without an external effort. This feature is generally used to hold loads.
Ball screws are efficient alternatives to lead
screws. In ball screws, ball bearings are recirculating between the screw rod
and nut. This results a significantly less friction than the power screws.
However, brakes are needed to stop ball screws from overhauling.
Lead Screw Calculator:
Note: 1 Single or multiple start Acme thread.
Note: 2 See Screw & Nut and Collar Friction Coefficients for Lead Screws
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RESULTS |
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Parameter |
Value |
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Nominal Diameter [D] |
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|
in |
|
Threads per inch [n] |
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|
--- |
|
Basic Pitch Diameter [D2] |
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|
in |
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TORQUE AND EFFICIENCY CALCULATIONS |
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Torque to Raise the Load [TR] |
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Torque to Lower the Load [TL]0 |
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Efficiency during Lifting [e] |
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Self Locking |
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Note 2: 2α is thread angle and 29 deg for Acme thread.
Note 3: l is the lead distance.