The name Neff traditionally stands for high-quality screw drives. Threads have been cut, whirled, rolled or ground for over 100 years. Today, the company offers solutions for threaded spindles and nuts. In addition to ball and trapezoidal screw drives in a wide variety of designs, it manufactures a large number of end products and systems. The catalog includes screw jacks in a wide variety of designs, telescopic screw jacks and, most recently, screw jacks with a gear housing made of crossed tubes. The value engineering approach was consistently pursued during development. This means that form has always followed function. The result is a worm gear screw jack series with an unmistakable design and countless application possibilities. Others see it that way too, as the company was presented with the internationally recognized IF Design Award 2018 for this series at a ceremony in early March.

Two characteristic crossed precision tubes take over the function of the traditional gearbox housing in the worm gear screw jack. This simplifies material variations. For example, stainless steel worm gear screw jacks for applications in medical, packaging or food technology can be realized without a great deal of additional effort. It goes without saying that the machining volume is reduced by up to 45 percent compared to conventional gearbox housings. This not only saves resources, but also reduces throughput times.

New application possibilities through flexible use
Based on the clear and extremely compact design of the screw jacks, a number of applications can be derived that cover a wide range of existing applications and open up new possibilities. Even the basic shape of the new gearboxes can be easily integrated into existing designs. The standard mounting plates can be fitted either above or below the drive journal. Varying the shape and connection dimensions of the base plates also opens up a wide range of design options. This means that the new worm gear screw jacks can be easily adapted to specific customer requirements or the existing hole patterns can be implemented when replacing existing drive solutions.

Lower costs with a more compact design
The tubes can also be manufactured in almost any length. With regard to the spindle tube, this has the advantage that the dimension between the base surface and the drive shaft can be varied without any problems. If the mounting plate is subsequently welded to the end of the tube, the spindle tube can be used as a support for very slim applications. An extended drive shaft tube in combination with a hollow shaft and a welded-on motor flange eliminates the need for the usual motor bells, resulting in a much more compact design and additional cost benefits. Thanks to the possibility of freely designing the screw-on flanges and tube lengths, the newly developed screw jacks can also be used wherever installation dimensions are restricted due to existing designs.

In addition to the existing worm gear screw jack types "N - Axially moving screw" and "R - Rotating screw", two further standard variants have been generated. A thrust cylinder design is created by extending the spindle tube as a guide tube. This flat guide allows the internal piston rod to absorb lateral forces, so that in certain cases additional guides can be dispensed with. The wiper at the end of the spindle tube protects its inner workings from dirt, moisture and dust. The drive system is therefore completely sealed.

Easy to implement swivel movements thanks to cardanic mounting
The second variant is created by extending the spindle tube in the opposite direction to the lifting direction. This also turns the spindle tube into a protective tube. Equipped with gimbal mounting options, this version can be used to easily implement swivel movements, such as in scissor lift tables or flap adjustments.

Equipped with cardanic mounting options, swivel movements, such as in scissor lift tables or flap adjusters, can be easily implemented with this design. (Image: Neff screw drives)

During the ordering process, the designer has the option of selecting different pre-selected variants via an illustrated overview and adapting them individually to his application by entering customer-specific details such as the stroke.

The proven Neff trapezoidal screws or Neff ball screws in various diameters and pitches can be used as screw drives. Sliding screw drives based on ball screws can also be selected, which have the advantage over trapezoidal screw drives of a larger core diameter and therefore greater resistance to buckling of the screw.

The accessories and attachments from the Neff modular system, such as mounting plates, clevises, joint eyes and bellows from the cubic worm gear screw jacks, can also be used for the new series. Various sizes for lifting forces of up to 150 kN are now also available.