Concrete mixer mainly includes mixing cylinder, frame, feeding, unloading, motor, power transmission structure, supporting device, water supply system, etc. In the process of work, the self-falling method and forced method are mainly used to realize the mixing of raw materials. The forced mixing method is mainly used in the mixing process of plastic concrete, while the forced mixing method is mainly used in the mixing process of hard or light aggregate concrete. The use of concrete mixer has greatly improved the construction quality and the construction effect of construction projects in China.
1 working principle of concrete mixer
The concrete mixer can mix and stir the building materials by rotating the bearing with blades in the cylinder and round groove. This mixing method can effectively reduce the artificial mixing time in the construction process and has become the main form of concrete construction.
The working efficiency of concrete mixer is mainly affected by working parameters. Concrete mixer is a mixer system controlled by many property parameters, and each parameter is interlinked and restricted with each other, which satisfies the work of mixer. The concrete mixer mainly includes five basic parameters: head, shaft power, blade diameter, slurry discharge volume and mixing speed. The shaft power in the above parameters is directly proportional to the blade power, fluid specific gravity, blade diameter value to the fifth power and speed value to the third power; The discharge amount is directly proportional to the first square of the blade diameter to the third power, the flow rate of the blade, and the speed of the blade. In addition, concrete mixer in the process of work also are constrained by the internal adjustment, mainly displays in: mixer blade rotation speed can be on the head and blade on the quantity of liquid control, low speed increasing blade diameter can produce high flow, shear rate after reaching a certain range can increase the mixing effect of mixing materials, etc.
After the concrete mixer is finished, the material in the mixer should be cleaned up in time, and the sundries and raw materials in the mixer should be cleared away to ensure the service life of the concrete mixer is improved.
2. Failure and maintenance of stirring shaft shutdown
2.1 causes of failure of stirring shaft stopping
In the process of using concrete mixer, it is very easy for the mixer shaft to stop, which is mainly due to the following reasons. First, the concrete mixer is overloaded. The overload of the concrete mixer can cause its own load to be too large, and the mixing speed of the shaft becomes slow, resulting in the reduction of the mixing effect of the mixer. However, when the load exceeds the mixing limit of the mixer, it is easy for the concrete mixer to stop running or suffer from excessive negative damage. Second, there is a large foreign body between the stirring blade and the side blade and the inner wall of the tank. It is very easy for the mixer to get stuck in the process of mixing. When the larger foreign body is between the stirring blade or the side blade and the inner wall of the tank, the normal operation of the two is very easy to be restricted and stagnation occurs. When stirring blade
Or when the clearance between the side blade and the inner wall of the tank is too large, the incidence of this phenomenon is very high. Third, the motor tape is too loose. In the process of using the concrete mixer, it is very easy to see the phenomenon of vibration loosening of the motor tape, which leads to the reduction of the transmission power of the concrete mixer and makes it impossible to complete the operation of loading mixing.
2.2 maintenance and treatment of shutdown fault
In the process of repairing the overloading of the concrete mixer, the operator can adjust the feeding amount appropriately to ensure that the feeding amount is consistent with the mixer load. To the situation of too much material to control in time, unloading excess material, reduce the possible overload operation.
In the process of dealing with large foreign bodies between the stirring blade and the side blade and the inner wall of the tank, the operator shall analyze the friction sound, stop in time when sharp and harsh sound occurs, stop the mixer for inspection, observe the fault location, and clean the foreign bodies. After the removal of foreign matter, the mixing blades and the clearance between the test blades should be led to readjust.
During the process of handling the loose motor tape, the operator shall check the parts of the loose motor tape, especially when the looseness causes the blender to stop running. Stop the machine in time, readjust the tension device, straighten the tape, continue to run after checking.
3 reducer failure and maintenance
Reducer is the key content of concrete mixer work, its work quality directly affects the overall construction benefit. In the process of concrete mixer construction, the reducer is prone to noise and high temperature faults, which affect the use of concrete mixer to some extent.
3.1 reducer noise fault and maintenance
3.1.1 reducer noise fault
The causes of internal noise of concrete mixer reducer mainly include two aspects. First, the reducer in the process of using internal foreign bodies. This kind of foreign body causes the concrete mixer reducer to appear the collision or the friction phenomenon in the use process, produces the violent noise. Second, the reducer bearing appears damaged. As an important component of concrete mixer reducer, reducer bearing is directly related to its normal use effect. Reducer bearing damage is very easy to cause friction at the joint, this friction causes a huge noise, resulting in damage or scrap parts.
3.1.2 reducer noise maintenance and processing
In the process of repairing the foreign body fault of the reducer, the operator should stop the concrete mixer and clean the foreign body in the concrete mixer reducer completely. When cleaning the operator to the reducer for disassembly and inspection, the presence of foreign bodies in the area for a comprehensive inspection, to observe whether there is part damage phenomenon. After making sure the parts are in perfect condition, the stirring operation can be continued.
In the process of maintenance and treatment of the reducer bearing fault, the operator shall observe the damaged parts of the bearing, analyze the huge noise that may appear in the bearing, and observe the bearing friction. The noise of the conventional reducer has a very high uniformity and the overall noise sound is small. When the bearing is damaged, the noise sound is increased and fluctuates, which will produce a certain frequency. If the bearing is found damaged after inspection, the bearing should be replaced in time.
3.2 failure and maintenance of excessive temperature of reducer
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Executive Editor:Zhang Wen