Worm Gear electric ball screw jack, anti-Rotation and higher pitches available
Translating(traveling screw) and rotating (traveling nut) configurations
Move loads and apply force more efficiently than other machine screw actuators
No self-locking! Due to the lack of friction, a holding brake is necessary: a engine brake or a spring pressure brake is required.
These worm gear screw jacks are extremely precision and reliability, it can meet all of the necessary basic worm screw jack safety, cost-efficiency, and durability mandates of the application. High strength bronze worm gear can be used, the payloads from 0.5T to 100T . A total of 11 sizes can be found, each in a touring nut version and a basic version.
The screw jacks can be used separately or in groups connected with drive shafts, joints, couplings, bevel gearboxes and additional mechanical components. In addition they can be powered by different motors: electric, with either AC electric motor or DC motor in addition to hydraulic or pneumatic motors. All these motion control products could be built-in many type jacking program arrangements or configurations.
Ball screw jacks are common where higher speeds and duty cycles are needed. Most screw jacks use trapezoidal screws Tr, because they’re basic, robust and inexpensive. The proportion of screw jacks that use ball screws is nevertheless constantly increasing. The reasons for this are mainly their pitch precision, their high efficiency (less power consumption and less heat generation) and the higher pitches obtainable, which permit higher stroke speeds.
A screw jack can add a machine cut lifting nut. For this model screw jack, just the bronze nut move together with the screw shaft. The lifting screw will not slide. It is definitely similar to the linear actuator working theory which converts rotational motion into linear motion. From this point to understand, a power linear actuator is a motorized screw 
jack.
The screw thread of screw jack could be acme screw and ball screw. So there are few variations of the screw jack. Commonly, machine screw jack and ball screw jack are available in your engineer task. Compared with acme screw, the ball screw can be better as there are ball bearings between your nut and screw. The anti-friction ball bearing can raise the ball screw efficiency.