ANSI/AGMA 9003-B08 pdf free.American National Standard Flexible Couplings – Keyless Fits.
The purchaser has the sole responsibility for specifying the peak torque and all other pertinent loading and operating information affecting the hub-to-shaft juncture. The machine designer is totally responsible for the design of the hub-to-shaft juncture. The sole responsibility of the coupling manufacturer is to provide hubs designed and manufactured according to the purchaser’s specifications.
Compliance with this standard does not constitute a warranty of the rating of the hub to shaft juncture under installed conditions. This standard only applies to the hub design. There can be personal injury or catastrophic failure of the shaft or hub-to- shaft juncture as a result of incorrect design, installation, or removal error, or other factors unrelated to the hub design.
WARNING: When working with hydraulic mounting and removal equipment EXTREME care and caution must be used to prevent personal injury and damage to equipment due to explosive axial movement at the time of hub release.
The equations in the following sections for hub pressures and stresses account for hubs of substantially uniform cross sections. The equation for torque capacity of the hub-to-shaft juncture assumes the hub outside diameter is uniform and equal to the outside diameter of the minimum hub section. The torque as calculated is conservatively low.
When a hub has multiple outside diameters such as shown in figure 1, the hub can be split into sections and the torque capacity of each section calculated separately. The total capacity is the sum of the separate section capacities. Hub configuration must be considered when performing stress and mounting pressure calculations (see figures 1,2, 3, and 4).
Shrink or interference fit analysis is generally based on Lame’s equations for a thick walled cylinder under internal pressure.
The bore used in the determination of the pressure for tapered and cylindrical bore configurations is as shown in figure 5. The following equations are based on the assumption that the shaft and hub have substantially equal surface finish, hardness, and modulus of elasticity.
5.1 Determination of interference fit required to transmit the specified torque
The interference fit required is dependent upon the design torque to be transmitted, the coefficient of friction selected, the physical dimensions of the hub and the specified speed of operation. The interference fit range is determined by either the minimum! maximum shaft and bore diameters for cylindrical bores, or by the minimum/maximum hub advance for tapered bores.
5.1.1 Apparent coefficient of friction, p
The apparent coefficient of friction, p. between the hub and shaft can vary widely depending on such factors as cleanliness, oil type, contact pattern, surface finish and rate of load application. Values which are widely used are:
p = 0.12 to 0.15 if hydraulically mounted with each surface having a finish of 32 microinches Ra maximum, and adequate draining time after mounting.
p — 0.15 to 0.20 if heat-shrink mounted with clean and dry surfaces, each having a surface finish of 32 microinches Ra maximum.ANSI/AGMA 9003 pdf download.