As far as possible, close to ideal reduction ratio: deceleration ratio = servo motor speed/decelerator output shaft speed.
Torque calculation: for the life of the reducer, the torque calculation is very important, and the maximum torque value (TP) of the acceleration should be paid attention to whether it exceeds the maximum load torque of the reducer.
Apply power is usually the servo on market model for power, the applicability of the reducer is very high, coefficient of work can remain above 1.2, but in use can also with their own need to decide, there are two main points:
A. The output shaft diameter of the servo motor shall not be greater than the maximum axis diameter on the table;
B. if the computed torque, rotational speed can satisfy the normal operation, but the net output servo have insufficient phenomenon, we can in the drive of the motor side, do current limit control, or on the mechanical shaft torque protection, it is very necessary.
The selection of general speed reducer includes the following steps: original condition, selection type and specification.
Type selection, by contrast, is simple, and accurate to provide working conditions of the speed reducer, master gear reducer design, manufacture and use is the key to the generic reducer reasonable choice correct specifications.
The specifications should meet the requirements of strength, thermal balance and axial load.
1. Select specifications by mechanical power or torque (strength check)
General reducer and special reducer design selection method is the biggest difference is that the former is applicable to various industries, but can only according to the working conditions of a specific design, so when the user needs according to their own requirements to consider different correction coefficient, the factory should choose according to actual motor power (playing nameplate is not rated power of gear reducer; Which is designed according to user's special condition, the coefficient, when the design generally have been considered, chooses as long as meet when using power less than or equal to the rated power of the speed reducer, the method is relatively simple.
General reducer is generally rated power each use (condition) coefficient of KA = 1 (motor or turbine as the prime mover, smooth machine work load, work every day 3 ~ 10 h, start times, 5 times or less per hour allowed torque startup torque for the work of 2 times), contact strength safety coefficient SH material 1, single failure probability of gear material 1%, calculate and determine the conditions of such as.
The rated power of the selected reducer should be satisfied: PC=P2KAKSKR is less than or equal to PN.
In the formula, PC -- computing power (KW);
PN -- the rated power of the reducer (KW);
P2 -- the power of the working machine (KW);
KA -- use coefficient, considering the influence of working condition, see table 1-1-6;
K -- -start coefficient, considering the influence of startup times, see table 1-1-7;
KR -- reliability coefficient, considering different reliability requirements, see table 1-18.
At present, the use coefficient of the countries around the world is basically the same. Although many samples didn't reflect on KS \ KR two coefficient, but because the bosom friend (working condition requirements for its clear), knowledge (features) on the performance of the gear reducer, model selection of the abroad generally have left a large amount of rich, equivalent to have considered the influence of KR \ KS.
Due to the use of different occasions, the important degree of different, the damage to the personal safety and production loss caused by the size different, maintenance easy, so for the reducer reliability requirement is not the same. The coefficient KR is the reliability of the original design to be corrected. It conforms to the requirements of ISO6336, GB3480 and agma2001-b88 (American gear manufacturers association standard) on the calculation method of gear strength. At present, the reliability of the reducer is not required by some users in China, but it can be specified in the design of general special speed reducer (SH is greater than 1.25, the probability of failure is less than 1/1000), and KR=1.25=1.56.
2. Heat balance check.
General the value of the allowable thermal power of gear reducer under the condition of the specific conditions (general environmental temperature 20 ℃, 100% per hour, continuous operation, power utilization rate of 100%), according to the lubrication balance to allow for maximum temperature (85 ℃). The condition is not simultaneously fixed by the corresponding coefficient (sometimes combined into a coefficient).
The selected reducer should be satisfied: PCt=P2KTKWKP is not equal to Pt.
PCt in the formula -- calculate thermal power (KW); Busbar processing machine.
KT -- environmental temperature coefficient, see table 1-1-9;
KW -- operation cycle coefficient, see table 1-1-10;
KP -- power utilization coefficient, see table 1-1-11;
Pt -- - reducer allowable thermal power (KW).
3. Radial load borne by the extension of the check shaft.
General reducer often must be around the middle of the input shaft and output shaft axis and allow the biggest under radial load limits, should be check, should be to the factory more than put forward bold trunnion and increase bearing requirements.