I.T.S. ITALIA SPA has introduced a new product : Recirculating ball screws ” JFK ”
But… what is a recirculating ball screws ” JFK ” ??
It is a screw type, so called because between the threaded shaft and the nut-screw, with a concave thread, are inserted steel balls which have the task to transform the sliding friction into rolling friction.
It is the most frequently used mechanism for transforming a rotary motion into a translational motion; recirculating ball screw is more accurate and provides an higher efficiency.
But… what are the benefits ??
Some of the benefits guaranteed by the use of recirculating ball screws are:
- High efficiency and durability
- Wear resistance
- Axial rigidity
- Reduced friction between the parts in contact
This type of screw is widely used on machine tools for the transmission of motion.
There are two types of recirculating ball screws:
1 ) internal recirculation patterns of the spheres: are preloaded and their re-circulation is returning them back after each round, at the previous, thanks to a swinging groove system planted ( situated ) within the lead nut. The size of the lead nut is smaller, the number of the balls is lower and thus are minor wear and friction,
2) external recirculation patterns of spheres: balls, after several rotations, are bring again at the beginning of the circle through an outer pipe to the nut, which consequently is more bulky. The coupling parts must have a cavity for the passage of return tubes. This model is advantageous in the case of long pitch screws and it is adaptable, unlike the previous model, at the addition of additives to increase the corrosion resistance and stability.
Recirculating ball screws need lubrication ??
Yes, to ensure a proper operation of the ball screw, a correct and appropriate lubrication is required. The choice of lubricant should be made taking into consideration:
– Working temperature
– Speed of rotation of the screw / nut screw
– nominal diameter of the screw
– load size- Level of system security
…. and then ??