IEEE 810:2015 pdf free download – IEEE Standard for Hydraulic Turbineand Generator Shaft Couplings and Shaft Runout Tolerances
4.1 Size
The shaft diameters included in this standard range from 90 mm to 2000 mm. Most shafts that haveintegrally forged couplings are of special design rather than a stock product,and the greatest possibleselection of sizes is required.For this reason,instead of following a series of preferred numbers， thesestandard shaft diameters are increased by 10 mm to 15 mm intervals, up to 230 mm; by 20 mm to 30 mmintervals,from 230 mm to 600 mm; and by 40 mm to 50 mm intervals,from 600 mm to 2000 mm. Largeforgings are difficult to procure and shaft diameters larger than 2000 mm are usually fabricated.Also, in these sizes,shaft stiffiness and torque requirements are achieved at lower cost with fabricated rather thanforged shafts.
4.2 Flange dimensions
In determining the proportions of the couplings included in this standard, the diameter of the flange, in eachcasc,has been kept as small as possible without reducing the strength of the coupling below that of theshaft in either torsion or bending.
Two values of flange thickness are provided: one for shafts that may be subject to bending at the coupling;and another for shafts not subject to bending at the coupling.However in the latter case, if the hydraulicthrust is unusually great, the same value of flange thickness between C and D should be used and couplingbolts of higher tensile strength steel may be found necessary.
4.4 Bolts and nuts
The number and diameter of the bolts are based upon the assumption that the torque is transmitted only byshear in the bolts and that the combined stress in the bolts may safely be as much as 30% greater than thecombined stress in the shaft.The diameter of the bolt body shall be determined from information given inTable 2.
NOTE—Hexagon head, round head, or stud bolts with nuts at both ends, may be used for all bolt diameters up to andincluding 130 mm at the discretion of the manufacturer. For bolts above 130 mm in diameter, the use of stud bolts withround nuts is recommended. The dimensions listed in Table 1 and Table 2 of this standard for shaft diameters of1050 mm and larger were based on this recommendation. For shaft diameters up to and including 230 mm, hexagonnuts were used to determine flange diameter.Heavy hexagon nuts were used for all other shaft sizes up to andincluding 1000 mm.5
The hexagon bolt heads (if used) shall correspond to the dimensions given in ISO 4014.
Bolt heads shall be of the same size as the nuts, or of the size corresponding to the body diameter of thebolts. In the latter case,one flat of the hex head shall be placed parallel to the periphery of the flange toprovide clearance for the nut guard.
The nuts shall correspond to the dimensions given in ISO 4032, and shall be of the sizes shown in Table 2of this standard.
Bolt heads and nuts beyond the sizes listed in ISO 4014 and ISO 4032 shall be dimensioned in accordancewith the formulas given in ISO 724.When used, round nuts or bolt heads shall have a diameter equal to orgreater than the across-flat dimensions given in those standards.
The bolts shall be straight (not tapered) and shall be fitted individually within the clearances specified inTable 2.The bolts and bolt holes shall be identified with corresponding numbers to facilitate assembly.
The length of the bolts shall be such that they will project slightly beyond the nuts. The diameter of thisprojecting portion,which is provided for driving when the bolts are being assembled or removed, shall besmaller than the root diameter of the thread. The thread pitch shall be as given in Table 2.
Different solutions for transferring the torque from coupling to coupling may be used according to themanufacturer design and calculation.Those solutions could include one or more of the following methods:friction,shear sleeve, dowel pin, or others.