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

Plastics Improve Roller and Cam Follower Performance

Posted by Alexander Bartosch on Oct 1, 2012 4:42:00 PM

When designing motion systems that require rollers or cam followers, many engineers still believe that only all-metal components will fit the bill. Yet rollers and cam followers with polymer bearing surfaces have emerged as a high-performance alternative to traditional metal components. 

In heavily loaded applications, polymers can withstand enormous forces if designed properly. For example, we’ve engineered and delivered polymer rollers that can withstand continuous forces up to 8 tons.

Most applications, however, are not so heavily loaded. The primary role of the roller or cam follower is to transmit motion, rather than support hefty loads. In these applications, off-the-shelf rollers and cam followers will do a good job without the need for custom engineering.

And increasingly, these off-the-shelf products are not made entirely from metal. Instead, they are hybrid designs that consists a polymer load bearing surface over a metal roller bearing or structural hub. Sized as drop-in replacements for standard sized metal rollers, the hybrid rollers offer some compelling technical advantages thanks to their use of polymers. 

These advantages include:

  • Self-lubrication. The engineering polymers best used for rollers, most notably gravity cast nylon 12, exhibit an internal lubricity that lasts for the life of the component. Bearing surfaces made from these polymers require no external lubrication between the roller and the rail, eliminating on-going maintenance costs and reducing the risk of failure.

  • Improved Wear. Even with some lubrication, metal-on-metal contact can result in excessive wear and galling. Plastic rollers eliminate this wear mechanism altogether. 

  • Contamination Reduction. Self-lubricated polymers eliminate two potential sources of contamination—stray lubricant and particulate from metal-on-metal contact. 

  • Smooth and Quiet Operation. Unlike metals, polymers such as gravity cast nylon 12 have the ability to dampen shock and vibration. 

  • Speed and Efficiency. Because they weigh about 40% less than similarly-sized metal rollers and cam followers, polymer products facilitate high-speed, energy-efficient motion.

  • Environmental Tolerance. Rollers made from gravity cast nylon 12 do not swell in moisture and also tolerate chemical exposures and temperature fluctuations. 

  • Cost Reduction. The true cost of cam followers and rollers has very little to do with their purchase price and everything to do with their lifecycle cost. Polymers save money over the long haul by eliminating the need for lubrication, extending maintenance intervals and eliminating metal-on-metal wear.

Our latest white paper delves into the technical advantages of gravity cast nylon-12 rollers and cam followers. It includes detailed comparisons nylon 12 with both metals and other plastics. Download it now.

Intech Cam Followers Out Perform MCGill and RBC Metal CamfollowersLearn More

Tags: cam followers, plastic rollers, cast nylon 12

How to avoid design compromises when the equipment function calls for cam followers

Posted by Alexander Bartosch on Sep 10, 2012 10:40:00 AM

 

How to avoid design compromises when the equipment function calls for cam followers

Engineering design is an art of compromise. To achieve a design goal — for example, a certain machine function — engineers select components based on several criteria such as functionality, reliability, component’s availability, cost, and lead times. Pro and cons are analyzed and final selection made.

In the case of cam followers, in the past engineers did not have a choice other than selecting the manufacturer. With few options available, the engineers were forced to accept a host of costly requirements and operational limitations.

Intech iCams

Whether the application calls for high or low load capacity, the design has to provide for lubrication either manually or through a central lubrication system. Rail or cam surfaces have to be hardened. In operation, lack of lubrication of the bearing or the rail surface can lead to a catastrophic failure. Over-greasing can lead to the cam follower’s skidding, causing wear, and excess grease can contaminate the product being processed.

In addition, shock and vibration can cause metal to metal impact that has to be considered. Metal particles and grease contamination often prevent equipment manufacturers from entering the growing clean room market. The relatively low rotating speed of needle bearings, their high rolling resistance, and inertia may be limiting factors in high speed equipment design.

When selecting Intech iCamFollowers® the designer can eliminate most of the disadvantages of metal cam followers. This is especially the case in designs where the cam follower’s primary function is to transmit motion and not its high load carrying capacity.

Today the trend is toward high speed, light weight, and light duty machines in processing, packaging, medical, and semi-conductor machines, which account for about 40 percent of applications. In these applications, Intech iCamFollowers® can easily carry the load, help simplify design, and better achieve the design goal.

Considering the cost associated with design and operation of metal cam followers, it pays to better understand the actual load carried by the cam followers in the application. With load data, including radial and axial forces, load duty cycle, and desired linear speed, Intech engineers can use a unique plastic roller life calculation to quickly assess whether an iCamFollower can be used.

The load capacity of Intech standard iCamFollowers® is listed on Intech’s web site and represents the maximum load the cam followers can safely carry for 100 million cycles, under both static and dynamic loads, without developing a flat or excessive wear. A consultation with Intech engineers may lead to an alternative designs, opening the way to eliminating wear and lubrication as well as the number of modifications in the machine’s design.

If iCamFollowers® can be used, the advantages, compared to metal followers are many:

For New Equipment:
* Simplified design- cost savings
* No need for surface hardening- c
an run on aluminum rails
* No rail or cam wear
* No need for lubrication- manual or automatic
* Reliability
* Higher machine speed- Lower inertia, low rolling resistance
* Shock absorption
* Wash Down- stainless steel bearings and shafts, sealed design
* Sub-zero temperatures
* Elimination of lubrication and metal particles c
an open new markets

In plant Operations:
* Eliminating Lubrication
* Eliminating rail and cam wear
* Cost savings on maintenance

* Cost savings on production shortfall
* Longer maintenance cycles
* Noise reduction
* Low cost to try if iCams work

 

Learn More

 

 

Credits: As featured in Design World May 9 2011. http://www.designworldonline.com/how-to-avoid-design-compromises-when-the-equipment-function-calls-for-cam-followers/#_

Tags: cam followers, reduce noise, reduce shock, reduce vibration, Self-lubricating, cast nylon 12, Clean rooms, moisture absorption, PA12GC, iCamFollowers, PA12C, PA12G, sub-zero temperatures, Cast Nylon

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

Flat spot development on steel/plastic rollers in skid steer cab door

Posted by Simon Barrell on May 26, 2010 4:00:00 PM

We wrote in our last post about wear on steel cam followers, below we have some more images that offer a great illustration of how flat spots occur when metal cam followers are dragged along the rail, typically because over greasing and insufficient radial load has caused the cam follower to stop rotating.

The pictures below show a metal cam follower with plastic sleave in a skid steer overhead cab door application, how the door is installed, and how the cab door roller failed. Since metal rollers were known to wear the aluminum rail, the original cab door cam followers were sleaved with Lubriloy RW-HI material (proprietary alloy of nylon 6,6). The aluminum tracks that the cab door rollers roll in are: extruded aluminum alloy 6063-T5 and 6063-T6, these also wore out to the point that doors jammed and had to be replaced.

Intech was approached by our customer to help them resolve repeated roller failure, using metal cam followers fitted with sleaves made of many different plastic materials. After completing a durability calculation Intech determined that a high load capacity roller is not necessary for this application. Instead we proposed a roller design that swapped out a needle bearing with Intech’s iCamFollower®, this has a ball bearing which offers less rolling resistance and does not need lubrication, as it has a long-lasting lubricant sealed inside the bearing.

 

Worn CamFollower resized 600
Damage can be clearly seen from the flat spot on this cam follower used in a skid slider cab door.


 

 

 

 

 

 

Three different methods were used to test Intech’s Power-Core™ cab door rollers: The first test was a simple endurance test, cycling the door open/close with a target of 4,000 cycles. The engineers let the test run for a total of about 7,000 cycles without seeing any wear on the iCamFollower®.

Worn CamFollower installed resized 600

 

 

 

 

 

 

 

 

 

 

The same worn plastic cam follower installed in the door sliding mechanism


Intech Power-Core™ rollers eliminate both the need to lubricate and rail wear and offer an ideal long-lasting solution in the demanding conditions, from extreme heat, vibration, torrential rain, to freezing temperatures, to which the Doggicam Super Slide is exposed.

Intech guide rollers are also used in mechanisms that move cameras in TV studios or on film sets, where smooth, vibration free and quiet camera operation is paramount.

iCamFollower
 

 

 

 

 

 

 

 

Intech’s Power-Core iCamFollower®


Encouraged by the results, the final test sequence for the Intech cam followers was to complete a series of cycles while introducing Laredo dust, to simulate the real working environment.

After initial tests with 1290 cycles, there was no material deformation on Intech’s Power-Core™ roller material, and the roller had not caused any wear to the aluminum tracks. “Looking good so far” reported the customer. Several days later he added: “I stopped the test today, as the cam followers have gotten to 6300 cycles (that’s about 4300 more than our requirement). There was no wear on the wheels of the cam followers, and no wearing to speak of on the cab door tracks. We were very surprised.”

After further examination of the set of cam followers in the test stand, it was determined that they were still in good condition, so the testing was restarted, this time covering the tracks and the rollers with Arizona Caliche dust, approximately every hour. Following this dry test, the tracks were sprayed down with water and a wet testing session took place. Once again the Intech’s Power-Core iCamFollowers® surpassed expectation and showed no wear, either on the roller or on the rail.

The force required to open the skid steer cab door using the smooth rolling Intech’s Power-Core™ material was reduced by half from 50lbs to just 25lbs. The ease of opening the cab door was subsequently turned into a key selling point for the machine.

Intech’s iCamFollowers® eliminate both the need to lubricate and rail wear and offer a cost effective alternative to both metal and other plastic cam followers in numerous applications.

Tags: cam followers, iCam Followers, lubrication-free, roller design, Intech rollers, Power-Core rollers, high load capacity, durability, rail wear, ball bearing, cab door, needle bearing, roller failure, skid steer

Are steel cam followers overrated for use in packaging machines?

Posted by Simon Barrell on May 12, 2010 4:40:00 PM

“Metal cam followers are overrated” said one packaging engineer in a recent conversation when asked why he opted for Intech’s iCamFollowers®. Here is why we agree with his opinion:

It seems that a large number of cam followers, metal ones that is, are used for their convenience not their load carrying capacity. Tap out a hole and you are ready to install a cam follower, providing designers with an instant “wheel” that allows parts of machines to move back and forth. The cam follower was not selected for its load capacity, rather enabling a movement required by the process.

There is a price to pay for this convenience. The rail on which the metal cam follower runs has to be periodically lubricated, as does the needle bearing in the cam follower. Lubrication, especially surface lubrication can contaminate packages and is a constant burden on maintenance. If you do not lubricate, the rail will wear and if you apply too much grease, there is a good chance that some of it will end up on the product. Over greasing of the cam followers’ needle bearing may cause the cam follower to stop rotating and instead be “dragged” along, causing a flat spot on the outer racer and excessive wear on the rail. This can happen when the radial load is relatively light for the heavy duty cam follower or if the radial load drops to zero during the operating cycle, for example on cams where the cam followers are used to exert force in only a portion of 360° rotation of the cam.

To replace a damaged cam follower is relatively inexpensive, while replacing a fixed rail or a cam can cost days of down time. Grease contaminated products carry their own cost.

Intech’s iCamFollowers® eliminate both the need to lubricate and rail wear and offer a cost effective alternative to metal cam followers in most packaging applications. The easy rolling, precision ball bearings thermally installed in the plastic tire offer very little rolling resistance and are lubricated for life. This ensures a smooth rolling motion even in light duty applications. Not to worry, the iCams will also carry heavy loads. Intech engineers developed a load / life expectancy calculation and the resulting load data allows engineers to select a cam follower suitable for the load in their application. So for example the IPC – 1.500 iCam will carry 300 lbs for 100 million cycles (1 cycle = one 360° rotation) without developing a flat or wearing out. Most importantly, it will not wear out the rail, steel or aluminum.

In addition to being able to carry high loads, the plastic tire will absorb shock & vibration, reduce rolling resistance, cut noise by up to 10 dB, and will work in sub-zero temperatures. For wash down applications the cam follower is delivered with stainless steel shafts and bearings. All this without lubrication or rail wear.

Intech’s iCamFollowers® also open up the way to more cost effective designs. Since iCamFollowers do not wear out the rails, designers can run the iCams directly on aluminum frames, without having to use steel or stainless steel strips to prevent rail wear. To further simplify the design central lubrication systems’ need for cam follower lubrication can be eliminated.

Are metal cam followers in your application overrated? Intech engineers can help you to determine that.

Intech iCamFollowers

Intech’s long-wearing, lubrication-free, heavy duty iCamFollowers® replace conventional metal cam followers

Tags: cam followers, iCam Followers, lubrication-free, vibration, roller life, rail wear, flat spot, outer racer, prceision ball bearings, radial load

Combating vibration, shaft bearings are only as good as their grease

Posted by Simon Barrell on Mar 16, 2010 4:02:00 PM

Intech Power-Core™ guide rollers and iCamFollowers™ absorb shock and vibration and their life is typically calculated for 100 million cycles, a performance relying in part on longevity of the roller bearings installed inside the plastic tires. Tests have found that degraded lubrication is the leading cause of bearing failure.

In harsh environments with high shock load frequency, combined with high humidity, some grease types can liquefy, then this will cause leakage from the bearing seals or can produce an added churning-friction effect on the bearing. As a result, in high speed applications, the operating temperatures will rise significantly, compounding the breakdown of the grease properties and resulting in premature bearing failure.

We have identified a new type of lubricant to improve our rollers resistance to shock and vibration by providing lubrication to the bearing when operating under extreme conditions. The grease, NLGI No. 2, has shown a consistent mechanical stability and less churning or deterioration than other lubricants.

We have been able to apply this newly acquired knowledge in a case of premature bearing failure in guide rollers used in a train sliding door in Florida. Exposure to high frequency vibration and high humidity caused a bearing failure while the plastic tire remained intact. By regreasing the guide roller bearings with the NLGI No. 2 grease, we have been able to better match the expected life of both the plastic tire and the bearings.

Intech Corporation is constantly striving to improve its products and certainly the discovery of this grease’s properties helps our customers extend the life of our rollers and bearings in shock and vibration applications.

Cam follower for packaging application 

 

 

 

 

 

 

 

 

Cam follower for packaging application

 

Concave, v-shaped, flat tire rollers

Concave, v-shaped, flat tire rollers

 Intech Rollers for High Security Door

Intech Rollers for High Security Door

Tags: cam followers, roller bearing, shock load, vibration, roller life, plastic tires, bearing failure, grease, lubrication