Hydraulics play a crucial role in the operation of tractors, assembly lines, and log splitters. Essentially, hydraulics refer to movements generated by liquid, enabling heavy-duty work across a variety of industrial applications. At the heart of this process is a complex system driven by a hydraulic pump. Read on to learn more about hydraulic pumps, their functions, and how they can benefit your business.
What Are Hydraulic Pumps?
Hydraulic systems are powered by pumps that convert mechanical energy into hydraulic energy. This hydraulic energy, necessary for actuators to function, relies on the interplay of pressure and flow—one cannot work without the other. When a hydraulic pump operates, it creates a vacuum at the pump inlet, drawing liquid from the reservoir into the inlet line, and finally into the hydraulic system.
Hydraulic pumps come in various types, each suited to different industrial needs. Hydrostatic pumps are positive displacement units, while hydrodynamic pumps are typically fixed displacement. Fixed displacement pumps have a set flow per rotation that cannot be adjusted, making them ideal for many everyday industrial applications.
Types of Hydraulic Pumps
Hydraulic pumps utilize fluid to power machines such as rams, cylinders, and motors. These pumps can be manually operated or motor-driven. Variable displacement pumps are particularly valuable because they allow operators to make adjustments while maintaining constant RPM input.
Common Types of Hydraulic Pumps:
-
Axial Piston Pumps: These positive displacement pumps feature multiple cylinders around a central axis, each with pistons connected to a swashplate. The swashplate's angle varies, controlling the pistons' movement and affecting discharge volume. They can be fixed or variable displacement pumps, useful in processes requiring controlled speeds.
-
Radial Piston Pumps: Unlike axial pumps, radial piston pumps have pistons arranged outwardly around a rotor hub. The rotor's movement forces fluid into and out of the cylinder cavity. These pumps can also be either fixed or variable displacement.
-
Rotary Vane Pumps: These pumps use rigid vanes around an eccentric rotor, moving along the housing wall to create smaller volumes that force hydraulic fluid out through the discharge port. The fluid amount can be adjusted per rotation to match the rotor's axis.
-
External Gear Pumps: Positive displacement systems using two gears on separate shafts, external gear pumps handle various fluids. They are ideal for fixed-displacement applications and high-pressure environments.
-
Internal Gear Pumps: With gears inside the shafts, these self-priming, non-pulsing pumps are bi-rotational, meaning one pump can both load and unload devices. Their simple design and reliability make them popular for many applications.
Custom pumps can also be manufactured to meet specific project requirements.
How Do Hydraulic Pumps Work?
Hydraulic pumps act as mechanical actuators, converting hydraulic energy into power by stimulating fluid flow to overcome pressure from the cylinder’s load. They perform two key functions: creating a vacuum at the pump inlet to draw fluid from the reservoir and pushing the fluid to the hydraulic unit. Essential components of hydraulic pumps include:
- Pump Housing: Protects the pump and its internal components.
- Impeller Blades: Move fluid inside the pump.
- Pump Shaft: Typically made of steel, mounts the impeller.
- Seals: Prevent contaminants from damaging the bearing assembly.
Other critical parts include pistons and fluid trap systems.
The Positive-Displacement Principle
Positive-displacement pumps deliver a consistent amount of fluid per cycle, regardless of pressure variations. This consistency is achieved by the close interaction between the pump housing and the pump element. Positive-displacement units can be either fixed or variable displacement. Fixed pumps maintain constant production levels based on pump speed, while variable pumps allow production adjustments by shifting the chamber axis.
Hydraulic pumps are vital for many industrial processes, ensuring efficient and reliable operation. PUSH Hydraulics offers a range of pumps tailored to meet your business needs, enhancing productivity and performance.