Views: 4 Author: Site Editor Publish Time: 2022-01-05 Origin: Site
（一） power end
1. Pump case
The bearing seat of the driving shaft and crank shaft is an integral steel casting, which is assembled and welded with the pump housing after processing and annealed after welding to eliminate the residual stress.
2. Driving shaft
The dimensions of the extended parts at both ends of the driving shaft of the mud pump are completely symmetrical. The pulley or sprocket can be installed at any end of the shaft. The bearing at both ends adopts the single row centripetal short column roller bearing.
3. Crank shaft
The structure of forging straight shaft and eccentric wheel is adopted instead of the traditional integral casting crankshaft structure of three cylinder pump at home and abroad. The casting is transformed into forging and the whole into assembly, which is easy to use, build and repair. Eccentric wheel, herringbone gear hub and shaft adopt interference fit.
4. The connecting rod is made of ZG35CrMo. The small end of the connecting rod is equipped with a pin shaft, and the two ends of the pin shaft are equipped with a single row of centripetal short cylindrical roller bearings, which are assembled on the crosshead body. The crosshead body is made of nodular cast iron, and the guide plate is made of nodular cast iron. The clearance between guide plate and crosshead is 0.26-0.38m. The cross head and the intermediate rod are connected by flange and bolt.
（二） hydraulic end
1. Valve box: the whole forging vertical structure is the drilling pump series with the smallest clearance volume in the domestic high-power mud pump. The three valve boxes realize liquid discharge and suction through discharge manifold and suction manifold. One end of the discharge manifold is equipped with a high-pressure four-way pipe and a pre pressure air case, and the other end is equipped with a lever type (single pin and multi-point) shear safety valve.
The discharged pre pressurized air case is an integral casting, with its body, capsule and sealing ring. The inflation pressure of the pre pressurized air case capsule is 20-30% of the maximum working pressure, but in order to ensure the lasting working performance of the capsule, it is better not to exceed 45.7 atmospheric pressure (650psi), in this case, the pressure unevenness can be guaranteed to be ≤ 5%.
2. Cylinder liner: bimetal cylinder liner is adopted, the inner layer material is high chromium wear-resistant alloy, the inner surface roughness is required to be within 0.20, and the inner surface hardness is ≥ HRC60. The specification of cylinder liner is Φ 100 - Φ 100. For user selection.
The piston is composed of piston core, leather bowl, pressing ring and circlip, meeting the standards issued by the Ministry.
The intermediate and piston rod are connected by clamps, which is convenient for loading and unloading. The adjustable medium rod packing box structure is adopted.
3. Cylinder head flange and valve cover flange are connected by trapezoidal thread.
4. Cylinder liner fixing method: the cylinder liners of 3nb-600 pumps are all fixed by union tightening.
5. Spray system: according to the user's requirements, the special electric centrifugal pump or the centrifugal pump driven by the driving shaft belt is used as the spray pump to cool and lubricate the cylinder liner through the nozzle on the spray box. Generally, the coolant is water or water-based solution (soluble emulsified oil or diesel oil can be added), and the coolant flows into the water tank for circulation; according to the water quality pollution procedure and the water temperature, the temperature is 0 ℃
6. Exhaust manifold assembly: adopt integral forging assembly welding structure. The front plane of the discharge manifold and the three valve boxes shall be screwed with bolts and cables, sealed with "O" packing, and the discharge valve chambers shall not collude with each other.