Machinery's Handbook, 31st Edition
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TRANSMISSION CHAINS 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 as standard 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 identi cal, are easily detachable. Each has a hook-shaped end in which the bar of the adjacent link 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 accu- rately made castings without machine finish. The links are usually connected 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 cyl inders cast or forged integrally with two offset side bars and each link identical. The links are joined by pins inserted in holes in 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, allowing for greater force and power transmission. 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-strand type 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 align ment 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, attach ments, and sprockets ANSI/ASME B29.1-2011 (R2016) and, where indicated, the data in the subsequent tables have been taken from this standard. These roller chains and sprock- ets 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 B29.1-2011 (R2016), customary inch-pound units were used. Metric (SI) units are given in separate tabulations in the ANSI/ASME standard. Nonstandard roller chains, developed individually by various manufacturers prior to the adoption of the ANSI/ASME standard, are similar in form and construction to stan- dard roller chains but do not conform dimensionally to standard chains. Some sizes are maintained from the originating manufacturers for replacement on existing equipment. They are not recommended for new installations, since their manufacture may be discon- tinued wihout ongoing support.
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