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

Stainless steel chain plating drum drive replaced by lube free gears

Posted by Simon Barrell on Jan 31, 2011 2:22:00 PM

One of our customers, who use an aggressive liquid bath in a plating process for coating metal parts, was experiencing a frequent breaking of the stainless steel chain drive which was corroding in the highly aggressive environment.

The parts are loaded into a large plating drum with a mesh exterior, which is then lowered into a tank containing a highly corrosive solution and heated to high temperatures between 120°F – 150°F. After coating, a series of cleaning and coating cycles are repeated across a battery of baths. A motor engages the drum drive, which needs to rotate slowly and steadily while carrying a high load into each step of the cleaning and coating process. The heavy metal parts in the drum can shift suddenly as the drum rotates, causing heavy shock load to be absorbed on the drive. The stainless steel chain, weakened by corrosion would give up under the shock load.

Intech engineers designed a large lubrication free Intech Power-Core™ gear and included a circular series of 2” diameter cast in ports made of Inconel™ in order to securely attach the gear to the drum. They also integrated a Power-Core bearing block in the shaft.

The Intech gear is resistant to the corrosive environment and was designed to absorb the sudden shock load, and proved to offer substantial savings to the customer.

Plating drum gears

Tags: Power-Core gears, lubrication-free, shock load, stainless steel, high load capacity, chain drive, plating drum

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