| The PowerFlex is essentially a very
cost effective power transmission coupling. The benefits
include no lubrication, no maintenance, no keyway requirements and
zero backlash. Plus, the product provides more torque for less money
than past Helical power transmission coupling offerings of the same
size range.
Four key elements have been incorporated to create the PowerFlex:
the HELI-CAL Flexure, the convenience of removable tapered bushings,
high torque capacity (up to 1800 lbin), and substantial misalignment
capability.
Early on in the PowerFlex design process, it was recognized that
the time tested and proven HELI-CAL Flexure should be utilized as
the key coupling component.
After reviewing various combinations of coil thickness, number of
coils, number of "starts" and flexure IDs, we arrived
at a double start HELI-CAL Flexure configuration that accommodates
sizable misalignments, and provides substantial torque capability,
high torsional stiffness, and reasonable pricing. This represents
value for the customer, which is always a key goal when we develop a
new series of couplings.
This innovative design provides a flexible shaft coupling that
can compensate for many operational variables, such as parallel
offset and angular misalignment present anytime two shafts are
being attached. The PowerFlexs unique flexing element also
accommodates axial motion between two shafts. The PowerFlex is
available in anodized aluminum and stainless steel. Shaft sizes
range from .50 to 1.75 inch diameter. Torque capacities range
from 250 lbin for the 2.0 inch OD
aluminum to 1800 lbin for the 3.0 inch OD stainless steel coupling.
The new couplings are configured with two flexing elements, each
consisting of two curved beams spaced 180 degrees apart. Each curved
beam is a spiral configuration that provides a beam long enough for
good flexibility, but short enough to be torsionally stiff. This
high torsional stiffness is exceedingly important in motion control
systems where position accuracy is critical. Each double beam
element can bend 2 degrees for a total of 4 degrees angular
misalignment. The flexing elements are used in pairs to allow for
parallel offset between two shafts.
The double beam
configuration of the PowerFlex provides a stability that makes it
well suited for high rotational speed applications up to 6,000 RPM.
Since all the flexing for misalignment is taken up by the beams,
(made from a single piece of material), the PowerFlex is perfect for
those troublesome power transmission applications. The single piece
flexing element makes this coupling essentially maintenance free.
Besides featuring high torsional stiffness, the PowerFlex is also
backlash free, making it particularly well suited to high torque
motion control applications. The PowerFlex offers considerable
savings in maintenance costs (there are none) in applications where
lubrication access is restricted or near impossible.
A tapered bushing attachment provides a positive method to hold
the coupling to the shaft. The bushings taper angle is low enough
to give good concentricity and torque transmission capacity yet high
enough to release the bushings from the coupling easily.
Installation is achieved by sliding the bushing up the shaft, and
placing the coupling into position. The bushing is tightened by progressively torquing the hex head screws to the specified
torque in a star pattern. This star pattern tightening sequence is
then repeated on the other end to complete the installation. Since
the holding capacity of the tapered bushing is more than the maximum
torque capacity of the coupling, keyways are not necessary.
Removal of the PowerFlex is accomplished by removing the hex head
screws from both ends. The tapered bushings are released from the
coupling by threading two of the hex head screws into the threaded
holes of the tapered bushing flange. By tightening the hex head
screws the tapered bushing is pulled from the coupling and the
friction taper attachment is released.
Because we machine precision bore sizes into the tapered
bushings, PowerFlex couplings can be assembled quickly to suit
customer needs and delivered fast. Customers also may make coupling
bore size changes themselves.
The PF Series PowerFlex is available in both inch and millimeter
bore sizes in aluminum or stainless steel. Many sizes are available
for immediate delivery.
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