The big difference between general reducer and special reducer design Selection method is that the former is applicable to various industries, but the reduction can only be designed according to a specific working condition, so users need to consider different requirements according to their own requirements when selecting. For the correction coefficient, the factory should use the actual motor power (not the rated power of the reducer); the latter should be designed according to the special conditions of the user. The coefficient that should be considered has generally been considered during the design. When selecting, as long as the power used is less than or equal to The rated power of the reducer is sufficient, and the method is relatively simple.
The rated power of the general-purpose reducer is generally based on the use (working condition) coefficient KA=1 (the motor or steam turbine is the prime mover, the load of the working machine is stable, the work is 3~10h per day, the number of starts per hour is ≤5 times, and the allowable starting torque is 2 times the working torque), contact strength safety factor SH≈1, failure probability of a single pair of gears≈1%, and other conditions are calculated and determined.
The rated power of the selected reducer should meet
PC=P2×KA×KS×KR≤PN
Where PC—calculated power (KW);
PN—the rated power of the reducer (KW);
P2—power of working machine (KW);
KA—service coefficient, considering the influence of service conditions;
KS—Startup coefficient, considering the influence of the number of starts;
KR—reliability coefficient, considering different reliability requirements.
The service factors used in countries around the world are basically the same.Although many samples do not reflect the two coefficients of KSKR, due to the confidant (clear about their own working conditions) and the enemy (clear about the performance characteristics of the reducer), foreign Selection generally leave A larger amount of wealth means that the influence of KRKS has been taken into account.
Due to different use occasions, different degrees of importance, different losses to personal safety and production after damage, and different maintenance difficulties, the requirements for the reliability of the reducer are also different.The coefficient KR is the actual required reliability to modify the reliability of the original design.It conforms to the provisions of ISO6336, GB3480 and AGMA2001-B88 (American Gear Manufacturers Association standard) on the calculation method of gear strength.Some domestic users have no specific requirements for the reliability of the reducer. According to the design regulations of general special reducers (SH≥1.25, failure probability≤1/1000), KR=1.25=1.56 is used for more important occasions.
