Enerpac Products UNI-LIFT M User Manual
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4.0 ACTUATOR FEATURES
Both M and B Series Uni-Lift
®
models incorporate a ground
alloy steel worm gear which drives a high tensile bronze gear
nut, accurately machined to high standards for maximum load
carrying capacity and uniformity of motion transmission. See
fi gure 1.
All shafts are mounted on heavy duty tapered roller bearings to
support the rated thrust load of the actuator while maintaining
correct gear alignment. The actuator housing is made of
aluminum or ductile iron, depending on model specifi ed.
The load screw is made of high quality steel that is ground to size
and precision rolled to form the threads. It is well proportioned
to handle the maximum load rating of the actuator. The load
screw upper end can be provided in threaded, plain, clevis or
“top plate” style, depending on model selected. Load screws
with double-clevis ends are also available as an option on some
models.
If needed, stainless steel or special alloy load screws can be
provided at additional cost. Protective bellows boots are
available as an accessory to protect the exposed portion of the
load screw, and to help keep the threads lubricated and free of
dirt.
On upright and double clevis models only, a protector tube is
furnished in order to keep the load screw threads lubricated and
free of foreign material.
Standard M and B Series actuators may be operated at a wide
range of input speeds. Units are recommended based on duty
cycle requirements and other customer supplied information.
5.0 LOAD SCREW CONFIGURATIONS
Uni-Lift
®
actuators are available in a choice of three different
load screw confi gurations:
1) Translating (refer to section 5.1)
2) Rotating (refer to section 5.2)
3) Keyed Translating (refer to section 5.3)
5.1 Translating
Travel
Clockwise
Rotation
Raises Load
Figure 2
Confi guration
On these actuators, the load
screw “translates” through
the unit to push or pull the
load. The load must be fi xed
to the screw and restricted
from rotation in order to
produce linear motion. See
fi gure 2.
An optional Anti-Backlash
feature is available
on selected
M-Series
Translating models. This
feature automatically
compensates for normal
thread wear to reduce load
screw endplay.
5.2 Rotating Confi guration
Travel
Clockwise
Rotation
Raises Load
Flange Nut
Motion
Figure 3
On these actuators, the load
screw is fi xed to the driven
gear, causing the screw to
rotate. A fl ange nut travels
along the exposed length
of the load screw to push or
pull the load. The load must
be fi xed to the fl ange nut
and restricted from rotation
in order to produce linear
motion. See fi gure 3.
The plain end of the load
screw and the fl ange nut
are pre-assembled on
these units. The plain end
is designed to fi t a standard
pillow block bearing,
to provide support and
alignment for the rotating
load screw.
Figure 1, Major Features and Components
Key:
1. Screw End
2. Load Screw
3. Tapered Roller Bearings
4. Driven Gear
5. Housing
6. Protective Tube
7. Input Shaft and Worm Gear
M-Series Models
B-Series Models