Specification for selection of universal speed reducers and special speed reducers:
The biggest difference of general reducer and special reducer design method is that the
former is applicable to all industries, but only by a certain reduction condition in
design, so the selection of users need to consider the correction coefficient according to
their own requirements, the factory should be according to the actual use of the power of
the motor reducer (not rated power according to the special conditions of users); the
latter design, consider the coefficient, the design in general has been considered, when
used as long as meet the use of power is less than or equal to the rated power can be
reducer, a relatively simple method.
General reducer rated power is based on the general use
(condition) coefficient KA=1 (motor or turbine as the prime mover, airborne kahei steady,
3~10h, every hour of the day starting times of less than or equal to 5 times, allowing the
starting torque is 2 times the working torque), the failure probability of safety
coefficient = 1% SH = 1, single contact strength on the condition of gear, calculate and
determine the.
The rated power of the selected retarder shall be satisfied
PC=P2KAKSKR = PN
Formula PC - calculates power (KW);
PN - rated power of the reducer (KW);
P2 - work machine
power (KW);
KA -- use factor, considering the influence of working condition;
KS - starting
factor, taking into account the influence of start-up times;
KR - coefficient of
reliability, considering different reliability requirements.
The usage coefficients are
basically the same in countries all over the world. Although many samples do not reflect
the KS\KR two coefficients, but because the friend (of their own conditions, (clear) tells
the performance characteristics of the reducer, the selection of foreign clear) generally
have a large amount of rich, equivalent to have considered the impact of KR\KS.
Due to the
different occasions, the importance of different, damage to personal safety and production
caused by the loss of different sizes, maintenance is difficult to different, so the
reliability of the reducer is not the same. The coefficient KR is the reliability of the
actual need to correct the reliability of the original design. It meets the requirements of
the ISO6336, GB3480 and AGMA2001 - B88 (American Gear Manufacturers Association standards)
for the calculation of gear strength. Some domestic users of the reliability of the reducer
is provided no specific requirements, design requirements according to the general special
reducer (SH = 1.25, the probability of failure is less than or equal to 1/1000), is an
important field in conjunction KR=1.25=1.56.
Heat balance check:
General reducer allowable
thermal power value is in certain conditions (usually the environment temperature is 20
DEG, 100% per hour, continuous operation, power utilization rate of 100%), according to the
maximum equilibrium temperature of lubricating oil allowed (85 DEG C) to determine the.
Conditions are corrected at the same time according to the corresponding coefficients
(sometimes synthesized into a coefficient).
The selected reducer shall meet
PCt=P2KTKWKP =
Pt
Formula PCt - calculates heat power (KW);
KT - environmental temperature coefficient;
KW -
operating cycle factor;
KP - power utilization factor;
Pt - the allowable thermal power (KW)
of the retarder.