|
|
|
 |
NEI's Conveyor Belt Products
Application
NATIONAL belts, being of steel construction, are especially adaptable to the conveying of heavy, rough or
sharp material. NATIONAL belts may also operate in fluids, oils or solvents. Handling of baled scrap, forgings, loose
metal scrap, metal chips, parts, stampings, waste paper and municipal waste are a few examples of the utilization of the
steel belt. The standard piano hinge steel belt is categorized as light, medium, medium heavy and heavy duty depending
upon the allowable belt pull. Different pitches and thickness in each category allows a selection of belt for a particular
set of operating requirements. Bearings may be used in single flange rollers for medium heavy duty and heavy-duty belts
allowing heavier live loads due to reduced coefficients of friction from the standard steel bushing. In general
coefficients of friction are 15 to 18 percent for steel bushings, 11 to 13 percent for nylatron bearings and 4 to 5 percent
for roller bearings. It should be noted that split outer race bearings are less expensive than solid outer race
bearings. However, solid outer race bearing affords double the loading and life of the split outer race bearing. We
recommend that all roller bearings be provided with grease fittings for pressure lubrication.
Construction
An assembled belt consists of hinged links, side wings, tubes, thru pins and dual strands of roller chain. The hinged links are assembled in horizontal rows by passing the tube through the hinges. The thru pins are inserted into the tube and fastened into the side chains thus supporting the links and causing the chain to take all the tension. The side wings are mig welded to the outer links.
The standard plain steel links are precision welded in widths of 24" for the 1/8" thick flat top and piano hinge plate belts and in widths of 6" and 12" for the 3/16" and 1/4" thick belts. The hinges are formed in 1-1/2" - 3" increments on the link thus allowing special belt widths of the same 1-1/2" increment.
Side wings are interlocked and afford continuous overlapping through bends and over the sprockets. They are mig welded to the belt, not spot welded, preventing thin pieces of material from getting under the wing. Standard side wings are: 1/8" thick x 1-1/2" for 2-1/2" pitch; 1/8" thick x 2-1/2" for 4" pitch; 3/16" thick x 3" or 4" for 6" pitch and 3/16" thick x 4" or 6" for 9" pitch.
The tubes are .760" I.D. x .970" O.D. steel running through the hinges for the complete belt width and rotates on the thru pin for a better bearing area. It is not necessary to disconnect the belt at a hinge point to remove a pin for maintenance purposes because the tube holds the belt together. The tube is used in all belts except the flat top and light duty piano hinge. Note that the pin, tube and hinge gives a 1-1/2" thick heavy-duty joint.
The thru pins are medium-carbon steel 1/2" diameter for the flat top and light duty belts and 3/4" dia. for medium, medium heavy and heavy-duty belts. Standard 1/2" dia. pin comes with the ends milled and 5/32" "S" pin. Standard 3/4" dia. pin is available with the ends milled and 1/4" cotter pin. The pin style used for the heavy duty belt is usually with ends milled & threaded and 3/4" lock nut. 3/4" dia. split pins can be furnished where extraction for maintenance purposes is a problem because of space limitations.
Return to top of page
Apron Belts
Bulk Handling Belts
Chain Drive Belts
Drag Flight Belts
Fastener Conveyor Belts
Furnace Belts
Hinge Plate Apron Belts
Quench Tank Belts
Roller Belts
Slat Conveyor Belts
U-link Belts
Wire Mesh
Return to top of page
Apron Belts
Standard flat top and NATIONAL piano hinge APRON steel belts are produced in 1-1/2", 2-1/2", 4", 6" and 9" pitches with 1/8", 3/16" and 1/4" belt thickness and with a variety of side chains for varied applications. Component parts of the belt are inventoried for expeditious delivery of new and replacement part orders.
U-link Belts
U-Link belts offer many advantages: maximum open area for free media circulation and drainage; a smooth, level surface; simple splicing and maintenance; and ease of cleaning. They are typically sprocket driven, with the sprockets preventing slippage. Material selection is equally important. 304 stainless are an excellent grade for applications for 500F - 1100F MAX. Type 310SS is utilized from 1000F-1600F MAX., and 330SS under severe heat and carburizing conditions.
Sprockets
With sprocket drives, enough sprocket teeth should be in contact with the belt components at all times so that the pressure put on any segment of the rod is not excessive. To put enough teeth in contact with the rods, the drive sprockets must be at least 10" diameter for belts up to 50 feet, and as large as 12" diameter for belts 100 feet. Sprockets should be so located that the teeth of the drive sprockets drive against the rods with the U-link legs trailing.
Sprockets should be spaced no further apart than 6" across the width of the belt. The outside sprockets should be three mesh openings from the edge of the belt to position the teeth against the rod and assure the load is properly supported. Our standard Cast Grey Iron sprocket is a 20 dual tooth sprocket at 9.59 inch pitch diameter, 10" outside diameter, with set screw and 1/2 X 1/4 key way.
Return to top of page
Copyright © 1999-2006 - National Element, Inc.
|