Datasheet

87
17
L LLb
F1
L1 LnL2
F2
Fn
Load Carrying Capacity and Service Life
17.2 Load Carrying Capacity and Service Life
L = Length of the (longer) carriage in mm
Lb = Carriage spacing in mm
Contact factor f
k
If multiple carriages are mounted back-to-back with minimal spacing (Lb < L), an
even weight distribution will be difficult to achieve due to the manufacturing
tolerances of the guideway elements and mounting surfaces. Installation situations
such as these can be allowed for with the contact factor f
k:
Number of carriages 1 2 3 4 5
Contact factor f
k 1 0.81 0.72 0.66 0.62
17.2.4 Dynamically Equivalent Load P
The loads (F) acting on a linear guideway system are subject to frequent fluctua-
tions during operation. This set of circumstances should be taken into account
when calculating service life. The varying load absorption of the guideway at
varying operating conditions during the travel distance is described as being the
dynamic equivalent load P.
P =
3

1
( F 1

·
L 1 + F 2

·
L 2 + ... F 

·
L )
L
P = 0.7 Fmax
P
F
1... Fn
Fmax
L
L
1... Ln
= Equivalent load in N
= Individual load in N during the partial travel distance L …. L
n
= Max. load in N
= L
1 + …+ Ln = Total travel during one load cycle in mm
= Partial travel distance in mm of one individual load during a load cycle
Total travel distance L
Total travel distance L
Load PLoad P
Stepped load
Sinusoidal load