The ball recirculation system is a structural component of ball screws that ensures the balls are continuously returned to the raceway after passing through the load-bearing threads. This enables the balls to circulate continuously between the nut and the screw.
Function
During operation, the balls roll in the thread raceways between the spindle and the nut and transmit the axial forces. At the end of the loaded area, they are guided out of the thread by the ball recirculation system, redirected, and returned to the start of the raceway. Without this system, only limited movement would be possible.
Types of ball recirculation systems
Depending on size, load, and installation space, different systems are used:
Internal recirculation
Redirection within the nut, compact design, often used for standard ball screw drives.
External recirculation (return tube)
The balls are guided via an external tube, which is robust and clearly visible, but requires slightly more installation space.
End-face recirculation
Here, the balls are returned to the starting position via an end-face deflection in the nut. This design is particularly suitable for high speeds and enables smooth running.
Single and multiple recirculation
Here, a suitable variant is selected depending on the number of ball circuits in order to increase the load capacity accordingly.
Importance for performance and service life
The ball recirculation system has a significant influence on:
- Smooth running and noise generation
- Permissible speed
- Wear and service life
- Ease of maintenance and lubrication
Precise redirection prevents ball impacts and ensures uniform force transmission.