ASME B29.2M pdf download

ASME B29.2M pdf download Inverted Tooth (Silent) Chains and Sprockets
SILENT CHAINS
11 Nomenclature
(a) Silent chain is a series of toothed links alternatelyassembled with pins or a combination of joint components in such a way that the joint articulates betweenadjoining pitches. As shown in Fig.l, illustration (a)side guide silent chain has guide links which straddlethe sprocket sides to control the chain laterally. As shownin Fig. 1, illustration (b), center guide silent chain hasguide links which run within a circumferential grooveor grooves for lateral control.
(b) Tpical Links. Since joint components, connectorsand offset sections vary with each manufacturer, theseitems are not included in this Standard. See Fig. 2 forexamples of typical links.
1.2 General Configuration
Link contour may vary but must engage standardsprocket teeth so that joint centers lie on sprocket pitchcircle.
(a) in. Pitch Chain and Larger. Chain widths equalto, or exceeding, two times the pitch have center guides.Narrower chains may be side guide or center guideChain widths exceeding 16 times the pitch are not recom-mended.
(b) %,in. Pitch Chain. Chain may be side guide orcenter guide as indicated in para. 1.8.
(c) Maximum Chain Width.Maximum chain widthshould be limited to approximately eight times the pitch
1.3 Numbering System
(a)% in. Pitch Chain and Larger. Two letters (SC) as aprefix, one or two numerals indicating pitch in eighthsof an inch, and two or three numerals indicating nominachain width in quarters of an inch. Thus, SC302 designates a silent chain, % in. pitch by % in nominal widthand SC1012 designates a silent chain, 1% in. pitch by3 in. nominal width.
(b) %, in. Pitch Chain. Two letters (SC) as a prefix, azero followed by a numeral indicating pitch in sixteenthsof an inch, and two numerals indicating nominal widthof chain in thirty-seconds of an inch.Thus, SC0309 designates a silent chain, % in pitch by %, in nominal widthNOTE: Where links are all of equal thickness 0.03 in. (0.76 mm)it is understood that the width indication also designates the totalnumber of links across the width of the chain.
1.4 Tolerance for Chain Length
(a) in.Pitch Chain and Larger. Chains will bedesigned and manufactured to fit gage sprockets. Tolerance for chain length for new chains may be over nomi-nal length 0.03 in./ft (0.76 mm/m) but must not beunderlength.
(b) / in. Pitch Chain. Chain length tolerance is0.02 in./ft (0.51 mm/m) over nominal length but mustnot be underlength.
1.5 Measuring Loads
(a)% in. Pitch Chain and Larger. Chain should be mea-sured under load of 25 1b x pitch in inches x width ininches + 20 Ib (0.1724 N x pitch in mm x width in mm+ 89 N). Length measurements are to be taken over alength of at least 12 in. (300 mm).(b) % in. Pitch Chain. The measuring load for in.pitch silent chain shall be approximately equal to 1 lb(4.45 N) for each link in the total chain width, i.e., theload for SC0315 would be 15 1b (67 N)Length measurements are to be taken over a length of at least 12 in.(300 mm).
1.6 General Chain Dimensions for 3 in. Pitch Chainand Larger
See Fig. 3 and Tables 1 and 2.
1.7 Chain Widths and Sprocket Face Profiles for3 in. Pitch Chain and LargerSee Fig. 4 and Tables 3 and 4
1.8 Chain Widths and Sprocket Face Profile for36 in. Pitch Chain
See Fig. 5 and Tables 5 and 6.
2 SPROCKETS
2.1 Tooth Form Dimensions for 3/s in. Pitch Chainand LargerSee Fig. 6.
2.2 Tooth Form Dimensions for 3/ in, Pitch ChainSee Fig. 7.