Mastering Ball Screws Pt. 1: Steel Ball Recirculation System and Characteristics

Mastering Ball Screws Pt. 1: Steel Ball Recirculation System and Characteristics

Share this Story

Ball screws are one of the many components seen throughout factory automation applications. Using the same concept seen with a bolt and nut, this assembly uses the rotary motion of the screw to actuate the nut in a linear direction.

A ball screw achieves its smooth linear motion by recirculating steel balls along the screw groove within the nut. The steel ball recirculation method differentiates the motion characteristics of the ball screw. Below we will explore the 4 main types of recirculation:

Steel Ball Recirculation Method Explanation
(1) End Cap Steel balls are recirculated by the end caps mounted within each end. Ball recirculation tunnels are constructed within the nut’s inner wall. Good with high speed operations.
(2) Deflector Deflectors are embedded on the nut outer tube to return the balls over the screw shaft per each lead. Suitable for compact designs.
(3) Return Tube Return tubes are mounted outside of the nut. The ease of assembly makes this suitable for mass production, however the overall size is relatively large compared to other methods.
(4) Guide Plate Uses guide plates or deflectors instead of the return tubes, and is good for making the design compact.

ball-screws-1

Methods 1, 2, and 3 are shown in much more detail in Figure 2.

ball-screws-3-images-to-1

Figure 2: In this figure we have three methods (In order of appearance): End Cap, Deflector, and Return Tube.

With a high level overview on the internal structure of ball screws, the concept of preloading will be easy to grasp. In the next article we will touch on preloading – the purpose and different methods.


Share this Story

Related Posts

Subscribe to our Channel

Like us on Facebook

Find us on Google Plus