IAI America RCS3PCR-SS8C - Manual (Page 51)

3. Life
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3. Life
One factor that affects the traveling life of an actuator is “Rated Load.”
There are two types of rated loads: “Static Rated Load” and “Dynamic Rated Load.”
� “Static Rated Load”: Load applied while the actuator is stopped, as a result of which minor pressure marks
are left on the contact surface
� “Dynamic Rated Load”: Load under which the actuator can travel for a specified distance and still meet a
specified probability of survival defined by no damage to its guide.
Manufacturers of guides indicate the life of each guide by a dynamic rated load based on a probability of survival
(no damage to the guide) of 90% after 50 km of traveling.
With industrial equipment, however, dynamic rated loads must be defined based on longer traveling distance of
5,000 km to 10,000 km given the moving speed, operating ratios and other operating conditions of these
equipment.
Also note that guides are generally designed with a sufficient life against radial loads. Moment loads that are
applied at positions away from the guide center are most damaging to guides.
The traveling life is calculated by assuming that the actuator travels 5,000 km or 10,000 km while receiving the
allowable load moment, based on a load coefficient of 1.2.
[For the allowable dynamic load moment, refer to 2, “Specifications.”]
� Models with traveling life of 5,000 km
RCS2- SA4C, SA5C, SA6C, SA7C, SA4D, SA5D, SA6D, SA4R, SA5R, SA6R, SA7
RRCS2CR- SA4C, SA5C, SA6C, SA7C, SA5D, SA6D
� Models with traveling life of 10,000 km
RCS2- SS7C, SS8C, SS7R, SS8R
RCS2CR- SS7C, SS8C
RCS3/RCS3P- SA8C, SS8C, SA8R, SS8R
RCS3CR/RCS3PCR- SA8C, SS8C
The formula for calculating the allowable dynamic load moment corresponding to a traveling life of 5,000 km is
shown below. If the traveling life is 10,000 km, replace “5000 km” in the formula with “10000 km”:
The life at the actual moment applied is calculated by the formula below:
C
IA
: Allowable dynamic load moment
fw : Load coefficient (= 1.2)
M
50
: Dynamic rated moment based on 50 km of traveling and
probability of survival of 50%
L : Traveling life (probability of survival: 90%)
C
IA
: Allowable dynamic moment
P : Actual moment applied