As opposed to the worm drive systems discussed here, a bevel equipment system could be used to convert rotation to linear movement. This would offer greater effectiveness to a machine screw jack because of it producing a rolling contact as opposed to the sliding contact of worm drive elements. It could, nevertheless, come at a greater initial cost and will not cover as better ratio range as worm drives.
Also known as power screws, lead screws come with several different types of thread profile which are ideal for different applications. Acme business lead screws are described by their trapezoidal thread profile and 29° flank angle and are commonly found in American Imperial machine screw jacks. An alternative solution to the Acme lead screw in a machine screw jack will be a square lead screw.
European or other international screw jacks utilise a trapezoidal lead screw with a 30° flank position and complies to an ISO metric regular.
Ball screw jacks require the thread of the lead screw to possess a profile that allows for the travel of the balls. To improve load distribution and minimise use, the ball screw monitor includes a gothic arch profile.
Reputation of the trapezoidal screw thread originates from the fact that it is simpler to machine and is therefore more economical than sq . and ball screw thread forms. Additionally, due to the large region of contact between your business lead screw threads and the worm wheel, there can be a large load carrying capability. This results in high friction which is certainly harmful to efficiency but does mean the system is more likely to end up being self-locking. This low performance means that such screw jacks are more suitable for noncontinuous or intermittent operation.

Many applications do not warrant the extra expenditure of a ball screw jack given that they do not require continual drive. In configuring a screw jack a prediction is made of the frequency of actuation and this will stage to the correct screw jack to become selected.

Translating Design Jacks are most often selected. With this style, a driven input worm functions on an interior worm gear causing the lifting screw to increase or retract. Operation requires that rotation of the lifting screw become prevented. This rotation it restrained whenever two or more jacks are tied to the same load.
Keyed Design Jacks are utilized any time rotation of the lifting screw isn’t restrained. For instance, when you need to lift the jack to meet a load. This is how they work: A key, fixed to the jack casing and inserted into a keyway milled in to the amount of the lifting screw forces the lifting screw to translate without rotating.
Keyed For Travelign Nut Design Jacks (KFTN) are another option. These jacks possess a fixed size lifting screw that rotates. Loads are attached to a flanged “journeying” nut that translates along the space of the rotating screw. This type of jack is ideal for applications that cannot support a screw safety tube or that want a flush mount
The worm wheel acts on the ball screw (via the ball nut) which actuates the lead screw. This system offers greater efficiency between the input and the useful output compared with a machine screw jack. Furthermore, it allows for higher actuation speeds and, due to the low friction, is very durable. Nevertheless a ball screw jack isn’t inherently self-locking and, because of its enhanced precision components, the original outlay is better. The resulting improved performance however implies this can be offset against smaller drive train parts and a significant decrease in the necessary power.