QSZ energy efficient central drive ball mill

  Ball mill is the key equipment of concentrator,and its power consumption generally accounts for more than 40%of the total power consumption of the plant.

  The working principle of

  All parts of the central drive ball mill are located on the same axis,successively installed with motor,hydraulic coupling,planetary gear reducer,discharge part,main bearing and cylinder body,etc.,to replace the central drive of conventional mill size gear peripheral drive.When the motor starts under no load and reaches the rated speed,the working oil in the hydraulic coupling passes the torque through the motor function to drive the planetary gear reducer and the mill barrel to operate together,so that the mill enters the working state.

  Structural characteristics of

  1：Hydraulic coupling is used to improve the starting performance of the mill

  The center drive ball mill adopts hydraulic coupling to realize the stage starting of the mill.The pump wheel connected with the coupling and the motor obtains energy from the motor and transfers it to the working oil.When the speed of the motor reaches a certain value after no-load starting,the working oil high-speed impact and the turbine connected with the load,so as to drive the load;When the working oil reduces the energy,it returns to the pump wheel for re-absorption of energy,so as to realize the energy transfer between the pump wheel(active)and the turbine(driven).Because the flexible connection between the pump wheel and the turbine is only realized through the working oil,it can isolate the torsional vibration and impact and make the load start smoothly.The coupling is also equipped with fusible plug,the mill due to overload and other faults make the working oil temperature rise,fusible plug melting,so as to protect the coupling and the mill.

  The ball mill has the characteristics of low speed,heavy load and large starting torque,but its load is basically stable when it works normally.Therefore,the installed rate of direct starting ball mill is far higher than the actual operation rate,resulting in energy waste.The center drive ball mill adopts hydraulic coupling to achieve the purpose of energy saving.

  2：Adopt planetary gear reducer center drive

  Conventional mill adopts single-stage cylindrical gear reducer and large and small gears to transfer power around the cylinder,which is open drive.Grinding dust,impurities easily enter gear clearance,coupled with inconvenient lubrication easy oil leakage,poor meshing conditions,and impurities resistance,so that the transmission efficiency is low,only 93%,and noise;Single-stage cylindrical gear reduction transmission efficiency is only 94%.The total rate of both is 88.7%,the center drive ball mill adopts double planetary gear reducer,transmission ratio is large,compact structure,stable operation,low noise,easy maintenance,transmission efficiency can reach 96%,compared with the conventional mill transmission efficiency increased by 7.3%,energy saving effect is good.Planetary gear reducer in and out of the axis is coaxial,so the new mill for the center drive.

  3：Main bearing adopts cylindrical roller bearing

  The mill is a heavy equipment with full load starting,and its main bearing is required to have a large bearing capacity.Babbitt alloy bearing bush for hollow bearing of conventional mill,lubricated with thin oil.However,this bearing bush and lubrication method has the following shortcomings:

  *As we all know,sliding friction is greater than rolling friction.Babbitt sliding bearing bush has high friction and positive force.Especially when the mill starts,the static resistance moment is large,and the tile surface wear is also large.

  *At the moment of starting,the mill has not reached the critical speed of forming lubricating oil film

  *As the main bearing is still in incomplete lubrication state,the starting torque of the mill increases and the starting time becomes longer,which has a great impact on the power grid

  *When the mill is running,the energy consumption of thin oil lubrication system is high

  *Because the main bearing is in a bad lubrication state when the mill starts,the machining accuracy of the bearing bush such as scraping is required to be high,otherwise it is easy to produce high temperature and burn the bearing,especially new bearing

  Center transmission ball mill roller bearing large double LieDiao heart to replace conventional di alloy sliding bearing,so as to solve the above problems,the bearing service life is long,good sealing,convenient disassembly cleaning,and equipped with manual pump time refueling,huang bearing in good lubrication condition,the thin oil lubrication system for the sliding bearing is simple and reliable.

  The center drive ball mill uses cylindrical roller bearings to reduce the friction and static resistance moment,coupled with the use of hydraulic coupling and planetary gear reducer,so that the configuration of motor power compared with the conventional mill reduced 10.7%-40.5%,energy-saving effect is more significant.