API 613:2003 pdf download

API 613:2003 pdf download.Special Purpose Gear Units for Petroleum, Chemical and Gas lndustry Services.
2.7.3.3 Each thrust pad shall be designed and riianuftctured with the dimensional precision uhickness variation) that will allow the interchange or replacement of individual pads.
2.7.3.4 Integral thrust collars are prekrred for hydrodynamic thrust bearings. When integral collars are furnished. they shall be provided with at least 3 mm (1/8 in.) ol’ additional stock to enable refinishing if the collar is damaged. When replaceable collars are furnished (for assembly and maintenance purposes), they shall be positively locked to the shaft to prevent fretting.
2.7.3.5 lloth flicex of thrust collars for hydrodynamic thrust bearings shall have a surfitce finish of 0.4 microns (16 micro- inches) Ra. or better and after mounting the axial total indicated runout of either face shall not exceed 13 piii (0.0005 in.)
2.7.3.6 Thrust bearings shall be sized for continuous operation under all specified conditions, including all external forces transmitted by the couplings. The external axial force transmitted by the coupling shall be considered as being numerically additive to any internal thrust forces.
2.7.3.7 Thrust bearings shall be selected such thai under any operating condition the load does not exceed 5O(- of the bearing manufacturer’s ultimate load rating. The ultimate load rating is the load that will produce the minimuni acceptable oil1ilm thickness without inducing failure during continuous service or the load that will not exceed the creep-initiation or yield strength of the babbitt at the location of maximum temperature on the pad. whichever load is less. (See Appendix t) for bearing selections based on loading. speed. and thrust shoe area.) In sizing thrust bearings, consideration shall be given to the following for each specific application:
a. The shalt speed.
b. The temperature of the bearing babbitt.
c. The deflection of the bearing pad.
d. The minimum oil-film thickness.
e. The feed rate, viscosity, and supply temperature of the oil.
f. The design configuration of the bearing.
g. The babbitt alloy.
h. The turbulence of the oil film.
The sizing of hydrodynaniic thrust bearings shall be
reviewed and approved by the purchaser.
2.7.3.8 If two or more rotor thrust flwces are to be carried by one thrust bearing, the resultant of the forces shall be used provided the directions of the forces make them numerically additive; otherwise, the largest of the kwces shall be used.
2.7.3.8.1 For couplings located so that the external force is produced by a single-ended drive motor wiLh sleeve bearings. the cxtcmal force shall be considered equal to the maximum magnetic centering force of the motor. If the maximum magnctic centering force is not specified, a forcc of 1.5 newtons per kilowatt (250 pounds per 1000 horsepower) motor rdted power shall be used.
2.7.3.8.2 For gear-type couplings (located other than as described in 2.7.3.8.1, the external force shall he calculated from the following fomula.