| Long Life Span and Long-term Maintenance-free Operation Thanks to the effectiveness of its ball retainers, the SKR has improved grease retention capability, allowing it to achieve a long life span and long-term maintenance-free operation. The SKR achieves a longer life span because its basic dynamic rated load at the LM guide and ball screw sections is greater than that of the conventional KR models (in the case of the KR3310, three times greater). The rated life span can be calculated by the following equation. LM guide Ball screw L = (C / P)3 X 50 L = (Ca / Fa)3 X 106 where where L : rated life span (km) L : rated life span (rev.) C : basic dynamic rated load (N) Ca : basic dynamic rated load (N) P : carrying load (N) Fa : carrying load in axial direction (N) From the noted equations, the greater the basic dynamic rated load, the longer the life span for both the LM guide and ball screw sections. |