gearing the annulus ring may be shaper cut. The pinion or gear of each
helical set shall be crowned to eliminate end loading. For helical gears,
standard normal diametral pitches shall be used. In addition to rating the
gears according to AGMA 6010 or AGMA 6023 as applicable, gear stresses
shall not exceed 80 percent of yield strength for any overload, motor
stall, or engine overload condition. No less than 350 percent of motor
rated torque shall be used for the motor stall condition.
2.4
SHAFTS
Each shaft shall be heat treated alloy steel. Input shaft size and
configuration shall be compatible with the motor or engine and clutch.
Output shaft size and configuration shall be compatible with the pump.
Welded shafts are not acceptable.
2.5
[COUPLINGS] [UNIVERSAL JOINTS]
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NOTE: The designer must delete inapplicable
statements. Couplings are to be used with electric
motor prime movers. Universal joints are to be used
with diesel engine prime movers. In some cases,
flexible couplings may be used with diesel engines.
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The speed reducer shall be connected to the motor (engine) by [flexible
coupling] [universal joints]. The [couplings] [universal joints] shall
have a service factor of 2 based on maximum rated load. In addition, at
maximum overload conditions, stresses shall not exceed 80 percent of yield
strength. [Couplings shall transmit torque by means of a steel grid spring
fitted into groves in the periphery of the coupling hubs or by means of
external gears on hubs engaging in internal gears on the coupling sleeves
or by hubs engaged with flexible self-lubricating members. Couplings with
sleeves held in place by snap rings are not acceptable.] [Universal joints
shall have forged steel yokes and spiders and shall have sealed needle
roller bearings. Universal joints shall be installed in pairs. The angles
between each shaft and the intermediate shaft shall be equal and shall not
exceed the manufacturer's recommendation. The driving pins on the yokes
attached to the intermediate shaft shall be set parallel to each other.]
[Couplings shall be enclosed and sealed to exclude contaminants and retain
the lubricant under both static and operating conditions.] The [couplings]
[universal joints] shall be dynamically balanced to AGMA balance
classification 7 or better and shall be grease lubricated unless
self-lubricated.
2.6
BACKSTOPS
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NOTE: Mounting of the backstop with the inner
member and rollers stationary will decrease wear and
heat generation and consequently increase the life
of the backstop. The outward radial load on the
rollers is decreased in this mounting situation.
This mounting method can be obtained without undue
cost but is not the standard mounting method for
these backstops. The designer may opt for the
standard method (inner member and rollers rotating)
but is advised that better life has been obtained
with the inner member stationary. For smaller
SECTION 15005A
Page 12
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