Transmision Chains

TRANSMISSION CHAINS

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TRANSMISSION CHAINS
Types of Chains
In addition to the standard roller and inverted tooth types, a wide variety of drive chains
of different construction is available. Such chains are manufactured to various degrees of
precision ranging from unfinished castings or forgings to chains having certain machined
parts. Practically all of these chains as well asstandard roller chains can be equipped with
attachments to fit them for conveyor use. A few such types are briefly described in the following paragraphs. Detailed information about them can be obtained from the manufacturers.
Types of chains.— Detachable Chains: The links of this type of chain, which are identical, are easily detachable. Each has a hook-shaped end in which the bar of the adjacentlink
articulates. These chains are available in malleable iron or pressed steel. The chief advantage is the ease with which any link can be removed.
Cast Roller Chains: Cast roller chains are constructed, wholly or partly, of cast metal
parts and are available in various styles. In general the rollers and side bars are accurately
made castings without machine finish. The links are usuallyconnected by means of forged
pins secured by nuts or cotters. Such chains are used for slow speeds and moderate loads,
or where the precision of standard roller chains is not required.
Pintle Chains: Unlike the roller chain, the pintle chain is composed of hollow-cored cylinders cast or forged integrally with two offset side bars and each link identical. The links
are joined by pins inserted in holesin the ends of the side bars and through the cored holes
in the adjacent links. Lugs prevent turning of the pins in the side bars ensuring articulation
of the chain between the pin and the cored cylinder.
Standard Roller Transmission Chains
A roller chain is made up of two kinds of links: roller links and pin links alternately
spaced throughout the length of the chain as shown in Table 1.Roller chains are manufactured in several types, each designed for the particular service
required. All roller chains are so constructed that the rollers are evenly spaced throughout
the chain. The outstanding advantage of this type of chain is the ability of the rollers to
rotate when contacting the teeth of the sprocket. Two arrangements of roller chains are in
common use: the single-strandtype and the multiple-strand type. In the latter type, two or
more chains are joined side by side by means of common pins which maintain the alignment of the rollers in the different strands.
Types of roller chains.— Standard roller chains are manufactured to the specifications
in the American National Standard for precision power transmission roller chains, attachments, and sprockets ANSI/ASMEB29.1M-1993 and, where indicated, the data in the
subsequent tables have been taken from this standard. These roller chains and sprockets
are commonly used for the transmission of power in industrial machinery, machine tools,
motor trucks, motorcycles, tractors, and similar applications. In tabulating the dimensional
information in ANSI/ASME B29.1M, customary inch-pound units were used. Metric(SI)
units are given in separate tabulations in the Standard.
Nonstandard roller chains, developed individually by various manufacturers prior to the
adoption of the ANSI standard, are similar in form and construction to standard roller
chains but do not conform dimensionally to standard chains. Some sizes are still available
from the originating manufacturers for replacement on existingequipment. They are not
recommended for new installations, since their manufacture is being discontinued as rapidly as possible.

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Table 1. ANSI Nomenclature for Roller Chain Parts ANSI/ASME B29.1M-1993

Roller Link D. — An inside link consisting of two inside plates, two bushings, and two rollers.
Pin Link G and E. — An outside link consisting of two pin-link...