Life estimate – Rockwell Automation Motion Analyzer Software User Manual
Page 256
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Rockwell Automation Publication MOTION-UM004B-EN-P - October 2012
Chapter 3
Understanding Your System Solution
3.4. Life Estimate
The Life Estimate tab provides information on the life and bearing load
utilizations for electric cylinders.
Figure 201 - Life Estimate Dialog Box
Table 151 - Life Estimate Properties
Parameters
Description
Operating Conditions
(label 1 in
)
The Hours per Day, Days per Week, and Weeks per Year assumptions are listed here. You can adjust these
values by clicking Change Operating Conditions.
Normal Forces and Moments
(label 2 in
)
To calculate the cylinder bearing load utilization, it is necessary to specify the mechanical forces and
moments applied to the moving part of the cylinder. All loads must be separately guided and supported.
Loads should align along the line of thrust throughout the complete stroke of the cylinders. If residual
radial or torsional loading cannot always be eliminated, enter these expected values here to help
determine if the loading exceeds the recommended limits of the cylinder. If so, counter measures such as
a rod-guide accessory and/or an adjustment to loading and mechanical connections may be necessary.
These values are not entered if a rod guide is used.
Normal Forces
These forces are applied at right angles both horizontally and vertically to the end of
the cylinder as shown in the diagram.
Normal Distances
These distances are from the end of the cylinder where each normal force is applied.
Moments
These moments are applied to the cylinder in the three planes. They are in addition
to any normal forces.
Life Estimate
(label 3 in
)
The roller screw or ball screw life estimate (depending on the linear actuator type) is listed here.
Bearing Load Utilization
(label 4 in
)
This information is available for Bulletin MPAI and MPAR linear actuators. The normal force and moment
utilization (Fz, Fy, Mz, My) and moment utilization (Mx) are displayed here as percentages.
Lubrication Schedule
(refer to
)
Applies to Bulletin MPAI electric cylinders.
Strip Seal Life Estimate
(refer to
)
Applies to Bulletin MPAS linear stages. The Slide Bearing Life Estimate and Strip Seal and Cable Track life
estimate is also listed.