Intech Power-Core Thermoplastics Engineering Blog

Eliminating Noise , Malfunction, And Skidding In Sliding Door Rollers

Posted by Alexander Bartosch on Jan 2, 2014 3:15:00 PM

Of all the maintenance headaches associated with sliding doors, rollers cause most of the pain.

Bombardier Station Door Roller resized 600

Metal rollers, while still the default choice for heavy doors, require ongoing lubrication. And even when lubricated, metal rollers can eventually wear out the door track. Plastic rollers, which are too often made from common engineering thermoplastic materials, lack dimensional stability when exposed to temperature extremes and moisture. They also tend to creep, developing flat spots under static load.

When poorly designed or maintained, both metal and plastic rollers can also be noisy. In the case of metals, the noise occurs because of the metal-on-metal contact with the track. In the case of plastics, the dimensional changes and flat spots make for a rough, noisy ride.

We’ve been able to address the most common pain points associated with sliding door rollers by combining Power-Core™ materials with high-end roller bearings. These hybrid rollers have started to appear in a variety of sliding doors, including ones with

  • High-cycle requirements
  • Heavy loads
  • Demanding operating environments

These applications include cargo van doors, mall security doors, machine tool doors and more. Power-Core rollers have a number of advantages over both metals and other plastics in sliding door applications:

  • What goes around stays round. Power-Core produces highly concentric rollers that stay that way in use. The concentricity comes from precision machining of roller surfaces. And the dimensional stability is an intrinsic material property. Unlike most polymers, Power-Core does not swell if exposed to moisture. Its also stable across a wide operating temperature range of - 40 to 80ºC.
  • No flat spots. Power-Core features an entirely crystalline molecular structure that makes it more resistant to creep that results in flat spots when rollers are statically loaded over time.
  • A nice quiet ride. Power-Core rollers can damp vibration more effectively than metals. Power-Core also exhibits lower rolling resistance than metals. Taken together, these two factors result in sliding doors that operate smoothly and quietly.
  • Keep on rolling. Power-Core rollers eliminate the metal-on-metal wear that can prematurely end of the life of metal sliding door rollers and tracks. And Power-Core needs no lubrication to keep rolling.

For more information on sliding door applications—including load capabilities and design tips—read our sliding door white paper.Overmolded Plastic Roller Alternative

Dowload Your Sliding Door Whitepaper

Tags: roller design, roller bearing, Heavy Duty Rollers, over molded rollers, sliding door hardware, van door rollers, train door rollers, Acetal rollers, UHMW rollers, Neoprene Rollers, Nylon Rollers

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