Roller Screw Accuracy and Installation

Accuracy

NRS planetary roller screws are produced in quality classes according to ISO 1, 3 and 5 standards. The summary of the characteristics and their allowable error are reported below.

Accuracy Class Tolerance* (µm)
G1 ±6
G3 ±12
G5 ±23

*Measured on a thread length of 315mm

EFFECTIVE THREAD LENGTH Lu ACCURACY CLASS
From (mm) To (mm) G1 G2 G5
Epm (µm) Vup (µm) Epm (µm) Vup (µm) Epm (µm) Vup (µm)
0 315 6 6 12 12 23 23
315 400 7 6 13 12 25 25
400 500 8 7 15 13 27 26
500 630 9 7 16 14 30 29
630 800 10 8 18 16 35 31
800 1000 11 9 21 17 40 35
1000 1250 13 10 24 19 46 39
1250 1600 15 11 29 22 54 44
1600 1800 - - 25 25 65 51

Installation

NRS planetary roller screws are precision components. They must be handled with care before and during installation to prevent the units from carrying radial loads or moments since either of these will impair the proper functioning and reduce the life of the system, or even cause the system to fail.

Nook engineers are at your disposal to address any concerns for the design of the adjacent construction and the bearing arrangement to maximize the usefulness of the NRS planetary roller screws.

Figure 1