"Floating Shaft" CD Couplings Shock-Proof Reciprocating Motion in Partition Inserters
Newly introduced Partition Inserters (Model SF-400) from Wayne Automation Corporation cycle once every second and travel 38" vertically. Every up/down cycle inserts solid fiber or corrugated partitions into cartons that hold bottles and plastic containers ready for shipment to the marketplace.
How do these Wayne inserters maintain repeatable accuracy 24/7 at these high speeds? The answer is their innovative design using servomotors connected to backlash-free Zero-Max CD couplings. These couplings damp out shock and vibration from the inserter's vertical reciprocating and intermittent motion and maintain insertion accuracy.
"To operate without problems, conventional vertical inserters require near perfect fiber or corrugated partitions," said Jay Bachman, vice president of engineering for Wayne Automation. "In contrast, the SF-400 inserters have designed-in features, including servo drive systems, that help deal with less than perfect materials. Unlike conventional systems which rely on gravity during the insertion process, the SF-400 maintains complete insertion control from the time the partition is picked off the magazine until it is fully inserted into the case. This ensures correct partition placement into the case every cycle."
Two Servo-Driven Timing Belts Smooth Inserter's
Start/Stop Cycling
The drive system for the SF-400 vertical inserter
mechanism is powered by an Allen Bradley servomotor connected to a planetary
reduction gearbox. The motor transmits torque to the inserter via a "floating
shaft" Zero-Max CD coupling configuration connected at both ends to two
gearboxes. These gearboxes are connected to two timing belt drive pulley
gearboxes.
Trouble-free, high-speed insertion
cycles are offered by the drive design using servomotors connected to
backlash-free Zero-Max Floating Shaft CD Couplings. They equalize tension on
right and left timing belts pictured above.
The Zero-Max Floating Shaft CD
Coupling is zero-backlash and torsionally stiff. It provides support for the
floating shaft component without imposing excessive radial loads on connected
equipment and bearings.
"The combination of both intermittent and reciprocating motions at 1,000 RPM (38" one-way travel for every one second cycle) is very demanding on the system's drive train," Bachman reported. "Torque loads are a big factor in this setup with cyclical peak torques approaching 60% of the motor torque with vertical load lift up to 200 lbs. We needed a coupling design that would handle these forces and one that we could position at both ends of the two gearboxes to equalize tension on both timing belts. We chose the Zero-Max CD 6F30-AC floating shaft coupling. We have confidence in CD couplings and have incorporated them in our system designs for nearly 10 years because of their unique performance features and dependability. They operate very well with servomotors and have become a key design element in our systems from the time we transitioned from air cylinder actuation to servo drives. Servo drives are energy saving, more reliable and require less maintenance, and the use of the CD couplings are important contributors to those benefits."
Intermittent Motion Controlled by Zero-Max CD Coupling
The Wayne SF 400 coupling application features a
28" span from one coupling's outer connecting hub to the second coupling's outer
hub. Also, this setup is a real test of each coupling's patented composite disc
design integrity that has a rated torque of 800 in. lbs (90 Nm). With similar
features to other good coupling designs, the CD coupling has one critical
difference - its patented composite disc pack design.
While the CD coupling disc pack transmits torque, it offers improved performance in dampening backlash and shock without coupling fatigue, which can occur in a fast-moving, high torque system like the SF 400. The disc pack at each shaft end resists fatigue through its patented open arm disc design. Made of durable composite material, the disc pack absorbs any shock from the servomotor's intermittent motion while maintaining a zero backlash condition. Also, the coupling's disc design and hub configuration provide support for the floating shaft component without imposing excessive radial loads on the connected equipment and bearings. Precision machining of the coupling components also gives the connection good dynamic balance for smooth, quiet operation.
Companion Erector System Utilizes CD Couplings in Power
Train/Clutch Mechanism
High speed is also a key feature of Wayne
Automation's VCE model case erector systems which assemble corrugated cartons at
the rate of 80 cartons a minute. Controlling motion in these systems with CD
couplings is equally important as in Wayne Automation's inserters. The VCE case
erectors employ CD couplings mounted to gearbox shafts. Two are standard model
6F45 couplings that transmit horizontal rotary motion and provide zero backlash
during operation and also when the system's clutch mechanism is actuated. This
clutch mechanism is positioned on the vertical shaft of the gearbox and is
comprised of a torque limiting clutch assembly and a special Zero-Max CD
coupler. This device allows an operator to manually stop and restart the feeding
mechanism as containers finish travel through the system to complete a case
packer run.
"Overall, CD couplings give our systems excellent performance and service life having replaced jaw and other type couplings a decade ago. The CD coupling was our first choice for the new SF-400 and it has proved very functional," Bachman said.
For more information contact:
Wayne Automation
605 General Washington Ave.
Norristown, PA 19403
610-630-8900
E-mail: sales@wayneautomation.com
Zero-Max
13200 Sixth Avenue North
Plymouth, MN 55441-5509
763-546-4300
Fax: 763-546-8260
E-mail: zero-max@zero-max.com