What is a basic overview of plunger pumps?

The plunger pump is a critical component of hydraulic systems. During operation, it relies on the reciprocating motion of plungers within the cylinder block to vary the volume of the sealed working chamber, thereby achieving oil suction and delivery. In fact, this type of plunger pump boasts advantages such as high rated pressure, compact structure, high efficiency, and convenient flow regulation.

Plunger pumps are widely used in hydraulic presses, construction machinery, marine applications, and other settings that require high pressure, large flow rates, and flow regulation. They are generally classified into single-plunger, horizontal-plunger, axial-plunger, and radial-plunger pumps. The basic structure of a plunger pump consists of an eccentric cam, plungers, springs, cylinders, and two check valves. A sealed volume is formed between the plunger and the cylinder bore. As the eccentric cam completes one revolution, each plunger performs one up-and-down stroke: during the downward stroke, oil is drawn into the cylinder, and during the upward stroke, oil is discharged. The volume of oil discharged per revolution of the pump is called the displacement, which depends solely on the pump’s structural parameters. In addition to these fundamentals, it is important to understand that a plunger pump typically comprises several plungers—usually three or six—arranged in parallel, all driven by a single crankshaft via connecting rods and sliders or an eccentric shaft. This configuration enables the reciprocating motion of the plungers, thereby achieving the intake and discharge of fluid. Naturally, such pumps also employ valve-type distribution mechanisms and are predominantly fixed-displacement units. In coal-mining hydraulic support systems, emulsion pumps are generally horizontal plunger pumps. These emulsion pumps supply emulsified fluid to the hydraulic supports at the coal-face working area. Their operating principle relies on the rotation of the crankshaft to drive the reciprocating motion of the pistons, thus accomplishing fluid intake and discharge.

Plunger pumps operate by utilizing the volumetric changes generated by the reciprocating motion of the plunger within the plunger bore, which is parallel to the drive shaft. Because both the plunger and the plunger bore are cylindrical components that can achieve highly precise fits, these pumps exhibit high volumetric efficiency. During operation, they primarily rely on a hydraulic reservoir pressurized by compressed air for oil supply; the machine can only be started and run once the reservoir has reached its operating pressure. Axial-piston plunger pumps are classified into two types: pressure-fed and self-priming. In practice, most pressure-fed plunger pumps employ a reservoir pressurized by compressed air, while some models are equipped with an auxiliary make-up pump that delivers pressurized oil directly to the pump’s inlet. Self-priming plunger pumps, on the other hand, boast strong self-priming capability and require no external oil supply. In summary, plunger pumps represent a new generation of high-efficiency pumps characterized by advanced technology. With the accelerating pace of domestic production, radial plunger pumps are bound to become an important component in the application fields of plunger pumps; radial plunger pumps are essentially piston or plunger pumps in which the direction of the plunger’s reciprocating motion is perpendicular to the drive shaft. As our factory’s flagship product, we are deeply grateful for the strong support from both new and existing customers. While consistently ensuring the reliability and quality of our products, we also strive to offer favorable pricing to our customers. Should you have any technical questions regarding our products, please feel free to consult us at any time.

The above article provides a basic overview of plunger pumps, as introduced by our editor. If you were previously unfamiliar with this topic, now is the perfect time to learn more. In the next installment, we will cover additional related knowledge—be sure to tune in!