Intech Power-Core Thermoplastics Engineering Blog

Actuator Redesign For High-Speed Belvac 795 Can Making Machine

Posted by Alexander Bartosch on Feb 25, 2013 12:01:00 PM

Though the necker on a can making line performs a very specialized task, the mechanical subsystems found on this machine offers a number of design lessons that can be applied more broadly by any engineer working to improve the performance and reliability of high-speed equipment.

Consider, for example, the necker’s cam-driven ram actuators. Mounted on a rotating turret and moving at speeds up to 250 strokes per minute, these rams push the round can shell onto a series of shaping dies that gradually reduce the diameter of the can to form its neck.

Traditionally, these Belvac rams have consisted of a round moving pin that translates axially within a barrel-like steel housing, with a machined keyway to keep the pin from rotating. The ram was driven directly via a pair of metal cam followers that mount on the rear end of the pin and engage a stationary cam.

That design, however, suffered from three problems in the field. For one, it required an aggressive lubrication regimen to combat ram and cam wear. For another, it allowed the pin to lift and twist in the barrel, causing premature wear that extends all the way back to the can. And lastly, the traditional design limited the operating speed of the necker.

We eliminated all three problems with a radical redesign of the ram that:

  • Eliminated the need for lubrication. The redesign replaced lubrication-hungry metals with lube-free polymers wherever possible. The redesign completely does away with the metal-on-metal wear between the cam and cam followers, which had been the primary failure mode with the traditional ram design.

  • Optimized the geometry of the ram. The redesign features a square ram, rather than round. The square ram does a far better job at managing the actuator’s on- and off-axis forces. It also guides the pin more effectively, reducing wear.

  • Removed moving mass. Thanks to the use of polymer components and structural aluminum, the redesigned ram weighs in at less than half the weight of the traditional round ram design. Total reduction of moving mass on a 10-stage line is nearly one metric ton.

Now in use by can makers around the world, the redesigned ram has offered a compelling payback. It has resulted in reduced maintenance costs, including the elimination of expensive automated lubrication systems. It has also contributed to reduced defect rates and faster line speeds.

Learn more about the redesign in our latest design case study, Redesign Improves High-Speed Can Making Machine. The case study offers a deeper look at our design process, including a glimpse at the finite element analysis (FEA) work that guided some of our decisions. The case study also highlights the side-benefits of designing for lubrication elimination.

 

Download the design case study

Tags: Belvac 595, cam follower, cam followers, reduce noise, reduce shock, reduce vibration, Self-lubricating, non-lubricated, cams, PA12GC, iCamFollowers, Cast Nylon, can making, low inertia, high load capacity, friction-reducing coating, production line shut-down, Belvac necker, Belvac 795, Belvac super k

Lube-Free Rotary Positioning for Cleanrooms and More

Posted by Georg Bartosch on Oct 3, 2012 3:58:00 PM

Intech’s Power-Core® rollers have found uses in applications ranging from industrial machines to transportation. Most of them have seen use in linear motion systems of one kind or another, but there’s no reason that these gravity cast nylon 12 rollers cannot be incorporated into rotary motion systems such as our new rotary index table.


iCam Turntable resized 600.gif resized 600Designed for integration into third-party servo systems, this new rotary index table makes extensive use of rollers and gearing made from Power-Core gravity cast nylon 12. The table’s drive mechanism consists of a pinion-driven ring gear whose helix tooth profile eliminates wear and backlash. The gravity cast nylon 12 gear is machined from a polymer blank that has been cast around an aluminum ring. This ring serves as a circular rail and as the mounting surface for the payload.The Power-Core nylon 12 rollers, which mount on the unit’s base plate, support the rotating gear and integrated mounting surface. They feature enclosed stainless steel bearings, making the unit suitable for washdown and other corrosive environments.

The use of gravity cast nylon 12 for the drive and bearing elements helps this rotary table outperform all-metal designs in several ways:

  •  Low wear without lubrication. This design avoids the metal-on-metal contact that can shorten the working life of motion systems. The only contact is between two Power- Core nylon components in the case of the drive mechanism and between Power-Core and aluminum in the case of the supporting rails. Power-Core nylon is formulated with an internal lubricant, so no external lubricant is needed. The metal bearings are lubed for life too.
  • Backlash free. Power-Core gravity cast nylon 12 gears offer a couple of intrinsic advantages when it comes to reducing backlash. For one, their dimensional stability eliminates the need for the backlash compensation required by moisture-sensitive plastics. For another, the uniform crystalline structure of Power-Core nylon 12 and our gravity casting production methods produce gear blanks with very low internal stresses and uniform machining resistance. These characteristics allow very precision machining of tooth profiles that have been optimized for backlash reduction–and would be difficult to achieve in metal. 
  • Fast and smooth. The low-inertia of the gearing and
    the rollers helps the table operate at higher speeds. By producing a tighter inertia ratio between the motor and driven load, the low inertia of the Power-Core drive components also makes it easier to tune the controls for a smooth, precise motion profile, particularly when moving light payloads. 
  • Washes down, resists chemicals. Power-Core nylon 12’s dimensional stability in the presence of moisture and its thermal stability make this rotary table a good fit for washdown, high-humidity and high-temperature applications that would prohibit the use of less capable polymers. Nylon 6, for example, can exhibit a dramatic loss in tensile properties and undergo dimensional changes when exposed to moisture and high heat levels. Power-Core nylon 12 also offers excellent chemical resistance compared to nylon 6 and other polymers used in power transmission applications. 
  • Cleanroom friendly. Because Power-Core nylon 12 resists wear and does not throw off the particulate associated with externally lubricated metal power transmission components, clean room use is a natural fit for this rotary table design. 
  • Scaleable. By manipulating the size of the gear and roller components, the table design can be scaled to handle payloads ranging from ounces to tons.

Read More About Indexing Tables

Tags: washdown application, cam follower, cam followers, cast nylon 12, Clean rooms, PA12GC, anti-backlash backlash gears, Index table

Introducing Intech Non-lubricated Linear Slides

Posted by Alexander Bartosch on Feb 2, 2012 1:09:00 PM

Below is the first look at our newest product: A non-lubricated linear Slide.

Tags: cam follower, cam followers, maintenance, Power-Core, precision machined, minimum resistance, iCam Followers, lubrication-free, reduce noise, reduce shock, reduce vibration, plastic rollers, Self-lubricating, wear life, composite material, cast nylon 12, Linear Motion Devices, Precision Linear Slides, electrically insulated, energy efficiency, Clean rooms, Wash-downs

Cam Followers for RT Light Testers in Can Making Production Line

Posted by Simon Barrell on Aug 27, 2010 11:26:00 AM

In a high speed can making production line, light inspection is required to find pin holes and split flanges after the necking process. Once cans have been coated and sealed, these finished cans are tested for leaks using a light tester, which can detect holes 0.002” wide, smaller than a human hair, and also spot cracked flanges as small as 0.015”.

When Intech iCamFollowers® are installed on the light tester ram they ensure that 3,000+ inspections can be performed per minute, more than sufficient to keep up with the high speed can production line and offer several important benefits.

After installation, the lubrication lines originally used to grease the metal cam followers can be disconnected, cutting down on periodic maintenance and possible contamination of the can. Another important benefit is the fact that the cam propelling the ram back and forth is now protected from wear by the IPC tire.

Fitted with precision ball bearings the Intech iCamFollowers® are easy rolling and the plastic tire does absorb shock and vibration for overall smoother performance.

The Intech iCamFollowers® have also been running successfully for many years in the necking operation on Belvac neckers, both on rams made by Intech, the light weight, self-lubricating square ram, as well as on the original Belvac rams.Light tester and cam followers

Tags: cam follower, cam followers, Self-lubricating, shock load, vibration, can making, icamfollower, light tester, necking operation