Ball Screw vs. Acme Screw Drive Systems
The chart below compares the primary differences between Ball and Acme Screw drive systems.
|Consideration||Acme Screw||Ball Screws||Comments|
|Audible Noise||Least audible noise||Most audible noise||Less audible noise than rolled screw||Less audible noise than precision screw||
Acme: no rolling elements provide for quiet operation.
Ball: recirculating balls in nut assembly transmit audible noise during motion; due to more accurate machining procedures - precision & ground ball screws are quiter than rolled ball screws.
|Back Driving Loads||May prevent back driving||Can easily back drive a load||Can easily back drive a load||Can easily back drive a load||
Acme: good for light loads & vertical applications.
Ball: recirculating balls in nut assembly producte a low friction system; vertical applications may require a brake to hold the load when no power is applied to the motor.
|Will increase with wear||Constant||Constant||Constant||
Acme: preloaded nut assembly eliminates backlash.
Ball: preloaded nut assembly eliminates backlash.
|Duty Cycle||Low to medium (< 50%)||High (100%)||High (100%)||High (100%)||
Acme: low duty cycle due to high sliding friction.
Ball: high duty cycle due to recirculating balls in nut assemble - high efficiency & low friction system.
|Life||Shorter due to higher friction||Long||Long||Long||
Acme: mechanical wear related to duty cycle, load & speed.
Ball: minimal wear if operated in proper environment, within load specifications, and periodically lubricated.
|Relative - Cost||Slightly more than rolled ball||Least expensive||Slightly more than rolled ball||Most expensive||
Acme: a little more expensive than the rolled ball screw.
Ball: due to more accurate manufacturing procedures precision rolled & ground ball screws are more expensive.
|Screw Efficiency||low (40% Acme, 60% Turcite)||High (90%)||High (90%)||High (90%)||
Acme: low efficiency due to high sliding friction.
Ball: high efficiency sue to recirculating balls in nut assembly - low friction system.
|Smoothness||Can be smooth||Least smooth||Medium smoothness||Smoothest||
Acme: due to friction can start/stop at very low speeds.
Ball: smoothness is constant through a wide speed range; due to more accurate manufacturing procedures precision & ground ball screws are smoother than rolled ball screws.
Acme: high friction can cause excess heat & wear at high speeds.
Ball: recirculating balls in nut provide for a high speed system due to low friction & high efficiency.