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Building Oil Shear Clutches & Brakes
since 1969
Call Today 800-829-3244

Force Control Industries, Inc.
3660 Dixie Highway
Fairfield, Ohio 45014 USA
Phone 513-868-0900 | Fax 513-868-2105

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ART Technologies STAMPS OUT DOWNTIME WITH FORCE CONTROL’S OIL SHEAR TECHNOLOGY

In the metal stamping business, precision, repeatability and uptime are key. But stamping accuracy suffers when improper tension on the coil feeders incorrectly supplies metal to the presses, resulting in off-spec parts and increased rejections. ART Technologies relies on an oil shear clutch brake to supply constant, reliable tension on the coil feeding one of their 400-ton presses to give them the precision and repeatability they need, with no downtime for maintenance or adjustment. When the plant is working 20 hours a day, that uptime is as critical as the tolerances they maintain.

ART is a full-service global supplier of precision metal stamping components, thrust bearings and coining services for raceways and washers. With 11 presses ranging in size from 45 to 800 tons, they stamp out a wide range of products for the automotive, truck, bus, solar, HVAC, agriculture, defense and other industries.ART Technology

They currently operate a single shift, but when business demands it they operate two ten-hour shifts, or nearly around the clock. Whether they are cranking out miniature thrust bearings for the automotive industry or thick stampings for the truck market, repeatability is key in all that they do.

A Pressing Problem

One of their Minster 400-ton presses has a ½ hp motor which pulls the stock strip though the press, keeping tension on the steel at all times. This tension is a necessity because of the Die Design, and ensures consistency of the stamped product and optimal productivity. Engineering Manager Fred Meinhardt, explains it this way: “We need to keep tension on the stock and to be able to run the drive unit at a speed slightly faster than the feed, so that when the feed stops, the clutch slips. When the feed restarts again, the stock tensioner takes up the slack and keeps tension on the stick as it moves forward.”

The company had been using a mechanical clutch that was slipping all of the time, with unsatisfactory results, including feed problems, out- of-spec parts, and press down time. In addition to the production problems, the dry friction clutch would wear and require adjustment, maintenance or replacement, to the tune of four to five hours per week. According to Meinhardt, the production loss due to downtime was 20 percent.

 Meinhardt estimates that the old style clutches were replaced every six months or so, in addition to the four to five hours per week of maintenance. At the time, the plant was working two 10-hour shifts, or nearly round-the-clock, so that level of weekly downtime for maintenance and adjustment was substantial and unacceptable. To top it off, the extra time to replace the clutch-brakes was even more troublesome, because the failures rarely occurred at convenient times. Then Meinhardt found help right around the corner, literally.

“My brother works for Force Control Industries (the manufacturer of the oil shear clutch brake) which is within a mile of our plant, so I knew all about their capabilities,” he said. Installing the oil shear clutch break was hassle free, and the little effort required reaped a significant return on investment. In the two years that the Posidyne 1.5 clutch brake has been installed on the ½ hp motor to tension the coil stock, there has been no unscheduled downtime for maintenance or repairs. At two years and running, the Posidyne 1.5 has already lasted 4-times longer than the dry clutch, and is still working fine.ART Technology2

How Oil Shear Technology Works

Normal dry clutch brakes employ a sacrificial surface—the brake disc or pad—to engage the load. Having no good way to remove the heat caused from engagement between the disk and plate, this material must absorb the heat. These extremely high temperatures will eventually degrade the friction material. As the friction surface wears away and begins to glaze, the ensuing torque fade causes positioning errors, which then require adjustment or replacement of the friction surface.

Oil-shear technology plays a major role in ensuring that the coil feeders at ART Technologies operates at peak efficiency—even at a much higher cycle rate. A fluid film flows between the friction surfaces, and is compressed as the brake is engaged. The Automatic Transmission Fluid (ATF) particles in shear transmit torque to the other side. This torque transmission causes the stationary surface to turn, bringing it up to the same relative speed as the moving surface. Since most of the work is done by the fluid particles in shear, by the time the surfaces actually meet or “lock up” wear is virtually eliminated.

In addition to transmitting torque, the ATF also helps to dissipate heat, thanks to a patented fluid recirculation system. Along with torque transmission and heat removal, the fluid also serves to continually lubricate all components—thus extending their service life. Oil Shear Technology also provides a “cushioned” stop that reduces shock to the drive system—further extending service life.

Unlike dry clutch brakes, the totally enclosed oil shear system is impervious to external elements such as wet, dusty or dirty environments, as are common in many manufacturing plants. Since the layer of oil eliminates wear, the Posidyne clutch brake provides a long service life. With elimination of wear comes elimination of adjustment—and increased “uptime” for ART Technologies.

The reliability and durability of oil shear technology helps plants with a critical pathway maintain high production. Oil shear technology has helped ART Technology’s plant increase precise control and stamp out downtime. Production is up 20 percent, with reduced scrap rates, fewer out-of-spec parts, and more parts per coil. The resulting efficiency and profitability keeps ART’s machines precise and reliable—giving them a competitive edge in a competitive industry.

For more information:
ART Metals Group Phone: (513) 942-8800 www.artmetalsgroup.com Force Control Industries Phone: (800) 829-3244 www.forcecontrol.com

APRIL 2017 Power Transmission Engineering

How a Wet Clutch Helps a NASA Facility
Stay Dry in the Big Easy

Oil shear technology enables remote actuation of stormwater drainage pumps and reduces downtime associated with maintenance.
by Ken Kelly

The Michoud Assembly Facility in New Orleans is a world-class manufacturing facility that provides vital support to National Aeronautics and Space Administration (NASA) exploration and discovery missions. The site contains one of the largest production buildings in the nation. It includes a vertical assembly facility that was critical for stacking components of the space shuttle’s external tank. From 1979 to 2010, 136 tanks were produced—all but one of which were used for spaceflight.

PosiClutch NASA3While Michoud is vital to the NASA mission—and to the site’s thousands of employees—stormy weather occasionally disrupts the production process. Heavy rains, a tropical storm or even a hurricane can cause flooding, but new oil shear clutches are helping to keep Michoud dry when Mother Nature unleashes her fury on the Big Easy.

New oil shear clutches installed on the vertical axial pumps engage fully with no slipping, chatter or squalling to allow the pumps to achieve their 60,000 gpm capacity. (Images courtesy of Force Control Industries) Clutch Problems Four vertical axial pumps with a rated capacity of 60,000 gallons per minute (gpm) were located in a remote pump station called Building 450 and designed to take stormwater away from the Michoud structures. Each pump was originally engaged by a twin-disc centrifugal clutch, and they were designed to operate at 1,800 revolutions per minute (rpm). When the clutches engaged, there was inherent slip and squeal, which resulted in incomplete engagement. “We survived Katrina,” facility engineer Bill Winsor recalled, “but barely.” When the pump station required a rebuild, the facility’s managers wanted a change. Among the options reviewed was an oil shear clutch that allowed remote actuation. The old style required an operator to manually engage and disengage the clutch, which meant sending somebody into the elements because the pump station was housed in a remote area of the facility.

Engaging centrifugal-style twin-disc clutches is accomplished at low speed, which means that they will slip until fully engaged. The slip-induced vibration caused a host of problems that included frequent repairs and rebuilds. Engagement was also a noisy operation, with a lot of squealing, but the noise was a minor inconvenience compared with the performance.

While the clutches were slipping and when they were not fully engaged, the 60,000-gpm pumps were evacuating far less than the specified amount—not an ideal scenario in pouring rain with stormwater accumulating. The pumps required increased time to evacuate the water, which can be problematic in a torrential downpour. In addition to pumping less water than required, the frequent adjustments and repairs to the centrifugal clutches w

 

ere taxing maintenance and operating budgets. So when Winsor began investigating the oil shear clutch, he was intrigued. The technology promised to eliminate adjustment and maintenance, while allowing remote actuation.

fter a year of operation, the oil shear clutch showed an improvement over previous equipment. “We have not had any problems with the oil shear design,” Winsor said. “They work the way they are designed to. We achieved remote actuation and eliminated all of the maintenance and repair headaches, downtime and expense that we experienced previously.”
Remote actuation of the clutches means that employees stay safe and dry during storms.

How Oil Shear Works

Normal dry clutches employ a sacrificial surface—a disc or pad—to engage the load. Having no good way to remove the heat caused from engagement between the disc and plate, the material must absorb the heat. The extremely high temperatures eventually degrade the friction material. As the friction surface wears away and begins to glaze, the spring force is reduced, causing torque fade and positioning errors that require adjustment or replacement of the friction surface.

Oil shear technology plays a major role in ensuring the axial pumps at Michoud can operate at full capacity. A fluid film flows between the friction surfaces, and as the clutch is engaged, the fluid is compressed. The automatic transmission fluid (ATF) in shear transmits torque. The torque transmission causes the stationary surface to turn, bringing it up to the same relative speed as the moving surface. Because most of the work is done by the fluid particles in shear, wear is virtually eliminated by the time the surfaces actually meet or “lock up.PosiClutch NASA

Vertical axial pumps move up to 60,000 gpm to keep the facility dry during heavy rains. In addition to transmitting torque, the ATF helps to dissipate heat through a fluid recirculation system. Along with torque transmission and heat removal, the fluid serves to continually lubricate all components, which extends service life.

The oil shear technology provides a cushioned engagement that reduces shock to the drive system—and further extends service life.
Unlike dry clutches, the totally enclosed oil shear system is impervious to external elements such as wet, dusty or dirty environments. Because the layer of oil eliminates wear, the clutch provides a long service life. The decrease in wear and adjustment means increased uptime for the stormwater pumping system.

About the Author
Ken Kelly is a regional sales manager for Force Control Industries, which manufactures oil shear
brakes and clutch brakes. He has been selling power transmission equipment since 1964 as a manufacturers’ representative with his own firm, and since 1995 directly for Force Control. He may be reached at This email address is being protected from spambots. You need JavaScript enabled to view it.