The cubic-type NEFF screw jacks (types M and J) are lifting elements that have enjoyed great popularity among users for decades due to their shape and characteristics. The screw drives from our own production, paired with high-quality worm gearboxes, result in screw jacks with outstanding properties in terms of lifting power and smoothness.
The lifting gear units are available with trapezoidal or ball screw drive with lifting forces from 150 to 500kN. The cubic design enables the use of the screw jacks in all mounting positions. As an N version with continuous spindle or as an R version with rotating spindle in combination with a running nut, the screw jacks can be assembled for the respective application. As a further expansion stage, the lifting elements in the N version can be supplied non-rotating by means of a square protective tube or V-groove.
By connecting individual screw jacks with drive shafts lifting systems can be realized in a simple way. With the rich accessories many problems can be solved with the standard program.
Type R is characterized by a rotating spindle with travelling nut. This means: the lifting motion is performed by the travelling nut, the lifting spindle remains fixed in its axial position. Thereby worm gear screw jacks type R can be mounted right on the base, without extra implementing space needed. It´s also an advantage that the screw jack is always located outside the gearbox housing. Therefore, less heat development in the housing allows longer duties in the same conditions. Worm gear screw jacks type R are available with either trapezoidal screw drives or ball screw drives with various nut-applications.
The N-Type worm gear screw jacks are characterized by the lifting spindle. Like all other NEFF-ball screws, Type N of the M-J series is available with trapezoidal ball screws as well as with ball screw drives. That is, the nut thread of the ball screw is in the center of the worm gear. Protected against twisting, the spindle is executing the lifting movement: the not rotating spindle is right through the gearbox housing. On the side of the load, worm gear screw jacks type N can be mounted with little required space. On the opposite side, installation space is required for the threaded spindle entering a protective tube. One advantage of this type: vibrations, which might be triggered by the rotation spindle and long lifts, are impossible.
Corresponding to Type N, the ball screw with the nut thread implemented in the worm gear is lead through the gearbox housing. Protection against twisting is achieved by linear bearing in a square protective tube on the gear side. Application for example, if due to the situation, the ball screw cannot be fixed against rotation.
As with Type N, in type VP the ball screw with the nut thread is also implemented in the worm gear, lead through the gearbox housing. Yet the anti-twist protection is realized by a feather key groove in the spindle. This type is only available with a trapezoidal ball screw, because of the persistent groove in the spindle.
