At the power end of the plunger pum

At the power end of the plunger pump, forced lubrication is usually applied. The lubrication oil is usually cooled by circulating water and the circulating water is cooled naturally by a cooling tower. For better utilization of the heat source, Fig. 2 indicates that the high-temperature water can be guided into and circulated within the domestic heat supply pipeline. Of course, the cooling water for the high-pressure water-cooled motor and the cooling water for the lubrication oil for the reducer in the pump assembly of the large-flow plunger pump can also be guided into this circulating system. The key point of this system, as shown in Fig. 2, is that the circulating water cooling realizes the cooling by pumping medium (for example, oilfield wastewater). As shown in Fig. 7, the circulating cooling water coil 6-1 is arranged within the suction-pressure stabilizer 6. When the circulating cooling water flows through the coil, the flowing medium takes heat away from the circulating cooling water. In this way, the circulating cooling water is cooled, so that the requirement of cooling the lubrication oil or the like is fulfilled. This structure is simple and compact, without resulting in the greenhouse effect.As shown in Fig. 6, crankshaft support roller assemblies 4 are mounted on a periphery of a crank 7-1 of the crank-link mechanism 7. Each of the crankshaft support roller assemblies 4 comprises a roller 4-1 and a fixed mount 4-3; a gap between each of the plurality of rollers 4-1 and the crank 7-1 is adjustable; and each of the plurality of rollers 4-1 is arranged on the fixed mount 4-3 and the fixed mount 4-3 is fixed on the box 16.Due to the large diameter of the plunger 2-7 in the large-flow plunger pump, the stress at the plunger 2-7 is usually above 160000N, and the stress at the power end is also high. Accordingly, the strength of the crankshaft is highly required. It is not ideal to solely increase the size or use high-strength material. Usually, a support bearing or a bearing bush is additionally provided on the crank 7-1 of the crankshaft. However, the precision for processing, mounting and maintaining the support bearing or the bearing bush is highly required. Furthermore, the support bearing or the bearing bush cannot be repaired if they are worn, and they are costly to use. As shown in Fig. 1, crankshaft support roller assemblies 4 are mounted on a periphery of a crank 7-1. Fig. 6 shows one structure of the crankshaft support roller assemblies 4. The crankshaft support roller assemblies 4, the number of which is not less than 3, are arranged on the periphery of each crank 7-1. The roller assemblies are mounted on the box 1 via a fixed mount 4-3. The roller 4-1 comes into contact with the crank 7-1. Adjusting screws 4-2 can be used to adjust the contact gap between the roller 4-1 and the crank 7-1.By supporting the crank 7-1 by the roller 4-1, the requirement for processing the chassis is low. The gap therebetween can be adjusted after they are worn. And, it is very simple to replace new ones if they are damaged.Although the principle and implementations of the present invention have been described above by specific examples in the present invention, the foregoing description of the embodiments is merely for helping understand the method and core idea of the present invention. Meanwhile, various alterations to the specific implementations and applications may come to a person of ordinary skill in the art according to the concept of the present invention. In conclusion, the contents of the description shall not be regarded as limitations to the present invention.