Page 738 - Sensors and Systems - North American Catalog
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Rotary Encoders
4
Rotary Encoders,
Absolute Rotary Encoders,
Standard
4
.1.1
Rotary Encoders,
Absolute Rotary Encoders
for hazardous areas
4
.1.3
Rotary Encoders,
Absolute Rotary Encoders
for safety applications
4
.1.2
Rotary Encoders,
Incremental Rotary Encoders
with pulse outputs
4
.2.1
Rotary Encoders,
Incremental Rotary Encoders,
Sine/Cosine
4
.2.2
Rotary Encoders,
Incremental Rotary Encoders
for hazardous areas
4
.2.4
otary Encoders,
Incremental Rotary Encoders
for safety applications
4
.2.3
Rotary Encoders,
Safety Speed Monitor
4
.5
Rotary Encoders,
Cable pulls
4
.3
Rotary Encoders,
Accessories
4
.4
736
Germany: +49 621 776-4411
Refer to General Notes Relating to Product Information
Pepperl+Fuchs Group
USA: +1 330 486 0001
Singapore: +65 6779 9091
Copyright Pepperl+Fuchs
Rotary Encoders
Introduction
2.4 Shaft load
Pepperl+Fuchs’ encoder shafts are mounted using two ball bearings. The
encoder’s service life is directly dependent upon the bearing’s structural
integrity, which is, in turn, dependent upon five main components:
•
Speed
•
Temperature
•
Axial load
•
Radial load
•
Load location (on the shaft)
Pepperl+Fuchs specifies maximum encoder shaft loading and bearing
service life based upon “worst case” permissible conditions (i.e. maximum
speed, temperature and shaft forces, where the load is centered/applied on
the shaft end).
With proper encoder mounting and selection of shaft couplings,
Pepperl+Fuchs’ encoders will provide a service life beyond the stated
value. Conversely, if mechanical loading is increased beyond the catalog-
specified limits, an encoder’s working life will be reduced.
Example:
At
6,000
rpm,
with
axial
and
radial
shaft
loads of 40 lbs, the RVI25’s specified service life is
2 x 108 revolutions. If the axial and radial shaft loads are reduced to
13 lbs and 9 lbs respectively, the guaranteed service life increases to
2 x 1010 revolutions.
3. Mounting Instructions
3.1 Mounting rotary encoders
Mounting rotary encoders with solid shaft using an L -bracket
3.2 Use of couplings
To prevent prohibited high loads on the bearing, a flexible coupling must
be used to connect the rotary encoder with solid shaft and the drive shaft.
Shaft offsets such as a radial, axial, or angular offset occur despite very
precise production and mounting of the drive shaft. This is often caused
by temperature effects. A rigidly mounted rotary encoder creates an over-
determined system with its clearance-free mount and the drive shaft mount.
The forces generated destroy the rotary encoder as a result of increased
axial and radial forces.
The higher the torsional rigidity of the coupling, the lower the torsional error
between the rotary encoder and drive.
The restoring forces of the coupling are directly related to the compensating
movement of the coupling. These forces must not exceed the permissible
axial and radial forces.
See the data sheets for details on the permissible radial, axial, and angular
offset.
Mounting bracket 9203
RVI58 with clamping
flange
Angular offset Δα
Δα
Radial offset Δr
Δr
Axial offset Δa
Δa
Spring disk coupling 9404
RVI58 with
servo flange
Synchro clamping element
from mounting set 9311
Mounting bracket 9300
Mounting a solid shaft encoder using a mounting bracket
