Metal-chain drives are normally used for applications below 3,000 rpm where accuracy and reliability must be greater than that provided by rubber belts. Because a metal chain does not stretch or slip as a belt does, chain drives maintain constant speed ratios under widely varying load conditions and need adjustment infrequently. Reliability of a chain drive is superior to that of belts, with chain service life typically rated at 10,000 hr, about three to four times longer than that of belts. Also, chain drives generally are more compact than similarly rated belt drives. For example, a 10-hp chain drive is about 50% smaller than a comparable belt drive. Chains can be replaced more easily than belts because sheave adjustment is not changed for the replacement. Chains can be removed by simply pulling out a master pin in the link and threading the new chain through the drives. But because chain drives do not slip, they cannot provide the overload and jam protection of belt drives. Also, the heavy weight of metal chain compared with light rubber belts produces penalties in efficiency, cost, and response time. Efficiency for chain drives -- about 85 to 90% -- is slightly less than that of conventional belt drives. And chain drives cost about 20 to 50% more than belt drives, with prices ranging from about $300 to $10,000 for 0.70 to 100-hp models. Chain drives use two types of links: self-forming teeth andextended pin. Self-forming teeth have slats that extend on each side of the link and conform to the ribbed sides of the sheave faces for a positive engagement. This type usually transmits up to 25 hp and operates at input speeds to almost 900 rpm. The extended-pin type, with pins projecting on both sides of the link to engage the sheave face, transmits
Products & Services
Silent chain or inverted-tooth chain features teeth on its links that engage the sprocket teeth. Silent chain can be wide and is used in a variety of power transmission and conveying applications.
ANSI Roller Chain Sprockets
Roller chain sprockets engage chain drives in power transmission and conveyor systems, though sprockets can engage any perforated material. Chain drives can be highly efficient and can produce a mechanical advantage as speed reducers/increasers. Sprockets conforming to ANSI standard B 29.1 are not meant to engage roller chains of any other parameter. ANSI conforming roller chain is smaller and somewhat weaker than its European counterpart.
ISO Roller Chain Sprockets
Roller chain sprockets engage chain drives in power transmission and conveyor systems, though sprockets can engage any perforated material. Chain drives can produce a mechanical advantage as speed reducers/increasers. ISO sprockets are designed to engage British Standard Chain and conform to ISO standard R606. These sprockets are not interchangable with ANSI defined sprockets.
V-Belts and V-Ribbed Belts
V-belts and V-ribbed belts are power transmission drive belts with a triangular or trapezoidal cross section. They are available in a variety of belt materials, reinforcement styles, and speed configurations.
Topics of Interest
There are three methods of transmitting power mechanically from shaft to shaft: chain drives, gears, and flexible belts. The chief advantage of chains and belts over gears is chains can be used with...
SILENT OR INVERTED TOOTH CHAIN
Silent or inverted tooth chain consists of a series of toothed links alternately assembled either with pins or with a combination of joint components in such a way...
Flat rubber belts were developed around the turn of the century primarily as replacements for leather belts. With the advent of V-belts, fewer machines were designed to use flat belts, and their...
In addition to the flat leather and fabric belts used in belt drives of the early 1900s, industry used hemp or wire rope running in grooved pulleys. These rope systems inspired development of the...
Timing belts and pulleys offer a positive drive through the engagement of molded teeth in the belt with accurately spaced grooves on the pulley. The action of belt teeth entering and leaving the...