Urethane elastomers are unique because they combine many of the advantages of rigid plastics, metals, and ceramics with the elasticity of rubber. Urethane resists abrasion and reduces the affects of shock and impact on load bearing capacity. Urethane covered rollers will not slip like PVC and will not mar conveyed materials which metal rollers are apt to do. Urethane provides the ultimate in wear resistance and noise dampening, making it the material of choice for our sleeved and tapered rollers. In addition, our urethane shaft adapters, when placed over the roller shaft ends, eliminate frame wear caused by metal-to-metal contact and extend the life of your conveyor frame. The advantages of urethane versus metal, plastic, and rubber materials are summarized below.
| Advantages vs Metal | Abrasion resistance Noise Abatement Corrosion resistance Toughness upon impact |
| Advantages vs Plastic | Non-brittle upon impact Elastomeric memory (when stretched will return to original dimensions) Abrasion resistance |
| Advantages vs Rubber | Abrasion resistance Cut and tear resistance Higher load bearing capacity Ozone resistance Colors available for color coding parts Harder durometer range Resistance to mold, fungi, etc Non-marking |
Limitations
When evaluating an application, the following material limitations need to be considered:
- Temperature: 200 ° F. max
- Steam: Exposure to steam degrades material.
- Chemicals: Certain acids and base chemicals will rapidly degrade material.
Urethane Roller Products
Sleeved Rollers
Ralphs-Pugh urethane sleeved rollers are well suited for continuous and intermittent gravity and powered applications. Rollers are available with a cast urethane cover or an interference fit sleeve. The cast urethane sleeve is secured with adhesives or locked in place through locking grooves on the core tube to prevent the sleeve from “walking”.
Tapered Rollers:
Ralphs-Pugh urethane tapered rollers are fabricated by casting a urethane taper over a steel core roller. The urethane is secured to the tube with adhesives or with the use of locking grooves rolled into the core. The urethane flows into the groove during casting and locks the sleeve in place. Rollers are available in standard turn radius configurations or custom turn radius designs to provide a true taper. True tapers eliminate the need for sideboards and result in directionally stable package handling.
Urethane Shaft Adapter Rollers
Ralphs-Pugh offers optional urethane shaft adapted rollers. Urethane Shaft adapters are an integral component of the roller and are inserted over the roller shaft ends eliminating the need for clumsy frame inserts. This unique design eliminates metal-to-metal contact between the shaft and the conveyor frame reducing noise from shaft to frame clatter and eliminates conveyor frame wear.
To help select the best match for your application please provide the following information:
- Small (SED) and Large End Diameters (LED) and Inside Turn Radius (Tapered Roller)
- Material Hardness (Shore A Durometer)
- Surface Finish
- Gravity or Powered (If powered, grooves or sprockets)
- Inside Frame Dimension (IF)
- Shaft Size/Configuration/Material
- Load and Speed
- Environment (Washdown, Hi-Temp, etc.
Roller Information
| Core Tube Materials: | Carbon Steel Galvanized Steel Stainless Steel Aluminum |
| Drive options: | Grooves and Sprockets |
| Shafts: | Roller shafts are spring loaded on both ends for easy installation and removal. End deburring is standard. |
| Materials: | Carbon Steel Stainless Steel Aluminum Zinc and Nickel Plating Available |
| Shafts: | Roller shafts are spring loaded on both ends for easy installation and removal. End deburring is standard. |
| Shaft End Options: | Hexagonal Round Threaded Drilled and Tapped Milled Flats Plastic Flat Caps Urethane Adapters Over Metal Through Shaft |
| Springs: | Standard is dual spring loaded with shaft depressing to the hub of the bearing. |
| Optional Materials: | Food Grade available |
| Drive Options for Tapered and Sleeved Rollers | Grooves for line shaft or motorized slave rollers. Sprockets on either end. Open area on core tube for drive belts. Metal drive ring over urethane for drive belt. |
| Colour | Standard Tapers: Black Sleeves: Black (70 durometer) Orange (80 durometer) |
Urethane Coating
Ralphs-Pugh offers two types of urethane coatings; cast and foam. Cast urethane is a high density polymer material. Standard hardness is 90 Shore A durometer. Urethane foam is a lower density material; its hardness can be varied between 50-90 Shore A scale. Since the foam type urethane is lighter than cast, it requires less power to drive a foam type roller. Cast urethane is available on tapered and sleeved rollers. Urethane foam is limited to tapered rollers. For assistance in determining which type of material is best for your application, please contact us.
Bearings & Bushings
Plated Steel/Metal Housings
These bearings are manufactured utilizing hardened steel balls and raceways. The outer raceway is either stamped or machined and lubricated with light oil. Grease packed bearings may be ordered for driven systems.
Plated Steel/Plastic Housings
Designed for light to moderate loads, the plastic housed bearings have hardened steel balls and stamped or machined inner and outer raceways. They are available with light oil or grease lubricant for driven systems. Plastic housings are available in conductive or non-conductive material with or without labyrinth seals. The labyrinth seal(s) provide protection to the bearing from dust, dirt, and airborne debris.
Stainless Steel/Plastic Housings
Designed for light to moderate loads, stainless steel balls and raceways provide an excellent solution for corrosive operating environments. For maximum protection against contamination, housing may be ordered with a double labyrinth seal system. Other housings are also available.
Precision Grade/ABEC-1
Designed for higher speeds and heavier loads, ABEC-1 precision bearings are available in chromium steel and optional 440, 304 or 316 stainless steel. ABEC-1 ball bearings and raceways are hardened, precision ground, and incorporate a ball retainer to eliminate bearing-to-bearing contact. Bearings are factory lubricated and sealed. Several seal/shield configurations are offered. Standard configuration is the LLB, Non-Contact Rubber Seal. Options include; 2RS Contact Rubber Seal and the ZZ Non-Contact Metal Shield. Bearing housings are available in metal or plastic. Plastic housings are made with conductive materials and available with or without labyrinth seals. Labyrinth seals provide additional bearing protection against dirt, dust, and other airborne contaminates. ABEC-1 bearings provide the highest load and speed capabilities, the lowest noise levels, and the longest life span of any available bearing unit.
Bushings
These non-ball bearing units are designed for light to medium loads and slow speeds. Typical installations are push conveyors and gravity conveyors. These are ideal for sanitary, rust and corrosion resistant, maintenance free wet or dry applications. Bearing materials include Ultra (Acetal plastic with Teflon internal lubricants), CS2 (Acetal), UHMW and ABS plastic. Bushing adapters include nylon, stainless steel, carbon steel and Ultra
Frequently Asked Questions
Q. Why should I consider conductive urethane hexagonal shaft adapters?
A. Two reasons: a) To eliminate shaft and frame wear caused by traditional metal to metal contact and b) to eliminate noise caused by shaft vibration. Urethane has exceptional wear resistance and noise deadening properties.
Q. My frames are older and vary in width, what will a urethane adapter do for me?
A. They will prevent additional wear to the punched hole, greatly reduce the noise level of your system and due to 5/8″ standard shaft extensions no further deterioration of the frame should occur. Ralphs-Pugh rollers do not use preload to “lock” the shaft into the punched hole. Our tests indicate that this locking style roller can increase wear and deterioration of frames.
Q. What is the maximum load rating for a roller with conductive urethane hexagonal adapters?
A. The maximum load rating for this style roller is 100 pounds. However, the concept of this adapter is to eliminate noise and wear which are typically caused by shaft vibration in the frame at higher speeds and with lighter loads.
Q. What does conductive mean?
A. When rollers are in motion they build up a static electrical charge. Non-conductive materials do not have the ability to dissipate this electrical charge. Persons coming into contact with the frame can receive painful shocks as this charge now dissipates through the person. Conductive materials allow this static charge to safely pass from the roller to the frame and eventually to ground.
Q. Are there any applications where these adapters shouldn’t be used?
A. Yes – In areas where the temperature exceeds 200 degrees Fahrenheit or where steam is used for cleaning and around strong acids or bases.
Q. Can I use these adapters around water?
A. Yes – Urethane can withstand water for years at low temperatures (less than 200 degrees Fahrenheit)
Q. What is inside this adapter to support the load? (i.e. are my mechanics safe on this roller?)
A. The adapter is supported by an internal 5/16″ hexagonal steel shaft that extends to within 1/8″ of the end of the adapter.
Q. Can this adapter be used in accumulation conveying systems?
A. Yes, the exceptional wear resistance of urethane makes it an ideal choice for this application (similar to urethane engine mounts) with the added benefits of sound reduction and no traditional metal to metal contact causing frame and shaft deterioration.