Double-pitch precision roller chains, attachments and associated chain sprockets for transmission and conveyors
1 Scope
This standard specifies requirements for double-pitch precision roller chains suitable for the mechanical transmission of power and for conveyors, together with those for their associated sprockets. It covers dimensions, tolerances, length measurement, preloading and minimum tensile strengths.
These double-pitch chains have been derived from some of the short-pitch transmission precision roller chains covered by GB/T 1243 having certain common dimensions but of double the pitch.
The chains are intended for use under less onerous conditions with respect to speed and power transmitted than are the base chains from which they are derived.
This standard primarily applies to sprockets with 5 to 75 teeth inclusive (with intermediate numbers of teeth 5½ to 74½ inclusive).
The preferred numbers of teeth are 7, 9, 10, 11, 13, 19, 27, 38 and 57.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the latest editions of the standards indicated below. For undated references, the latest edition of the normative document applies.
GB/T 1800.3 Limits and fits - Bases - Part 3: Numerical values tables of standard tolerances and fundamental deviations (GB/T 1800.3-1998, eqv ISO 286-1:1988)
GB/T 1243 Short-pitch transmission precision roller and bush chains attachments and associated chain sprockets (GB/T 1243-2006, ISO 606:2004, IDT)
3 Transmission chains
3.1 Assembly and component nomenclature
The nomenclature of the chain assemblies and their component parts is illustrated in Figures 1 and 2.
Note: The figures do not define the actual form of the chain plates.
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Foreword i
ISO introduction iii
1 Scope
2 Normative references
3 Transmission chains
3.1 Assembly and component nomenclature
3.2 Designation
3.3 Dimensions
3.4 Tensile testing
3.5 Preloading
3.6 Length validation
3.7 Marking
4 Conveyor chains
4.1 General
4.2 Nomenclature
4.3 Designation
4.4 Dimensions
4.5 Length validation
4.6 Marking
4.7 Attachments
5 Sprockets
5.1 Nomenclature
5.2 Diametral dimensions and tooth shape
5.3 Radial run-out
5.4 Axial run-out (wobble)
5.5 Pitch accuracy of sprocket teeth
5.6 Bore tolerance
5.7 Marking
Annex A (normative) Pitch circle diameters
