Thermal power calculation of planetary reducer
There are two parameters in the power selection standard of planetary gear reducer stipulated by our country: one is the mechanical power, that is, the power determined under the strength conditions of the main parts of the gear reducer (gear, shaft, etc.); The second is thermal power, that is, the maximum operating power determined when the ambient temperature is normal temperature and the load of the speed reducer continuously runs to the allowable temperature of the thermal balance state, which is an important indicator for the selection of planetary gear reducer.
Thermal power is the maximum power that the planetary reducer can continuously transmit within the specified lubricating oil balance temperature range. Equilibrium temperature is the lubricating oil temperature at which the heat generated and emitted by the lubricating oil during continuous operation is basically balanced and the temperature rise is basically stopped. The thermal power depends on the efficiency, working conditions, maximum allowable oil tank temperature (lubricating oil temperature) and cooling measures taken for gear pair, bearing and other parts. The use of more than thermal power means that the oil film thins or breaks, reduces its ability to resist pitting and scuffing, and shortens its working life.
With the increase of the mechanical power of the planetary reducer, the proportion of its thermal power decreases, with a minimum of about 20%. For the belt-driven reducer, due to the lack of proper heat dissipation measures, the limit caused by low thermal power can only be compensated by reducing the use of its mechanical power, so that it is in the state of "big horse pulling car". Otherwise, it will lead to high operating temperature, failure of lubrication system, and even mechanical thermal damage, gear scuffing, bearing burns, etc. This will only make the working capacity of machinery and equipment not be used and developed satisfactorily, resulting in great waste. It can be seen that the increase of the thermal power of the reducer is closely related to the effective heat dissipation measures. In order to ensure a good heat dissipation effect, it is necessary to install a forced heat dissipation device on the reducer. In the domestic industrial standards, Babman Industrial Technology generally recommends that the reducer adopt oil pool lubrication, natural heat dissipation and disc-shaped head forced cooling, while for the reducer with special power, it emphasizes the use of circulating lubrication and cooling.
It is necessary to determine the thermal power of the planetary reducer and apply it according to its thermal power, or take auxiliary cooling and heat dissipation measures to increase its thermal power, so as to make better use of its mechanical power.
