Gear hydraulic pumps are positive displacement pumps, which means they deliver a fixed amount of fluid per revolution. They are commonly used in hydraulic systems due to their simplicity, reliability and efficiency.
Components of gear hydraulic pump:
Housing: The pump's housing contains the gears and provides support for other components.
Gears: Gear pumps usually consist of two gears - a driving gear (input shaft) and a driven gear. These gears are precision machined and mesh tightly together.
Inlet and Outlet: The pump has an inlet and outlet for fluid to enter and exit the pump.
Seals and Bearings: Seals prevent fluid from leaking out of the pump, while bearings support the rotating shaft.
Working principles:
Fluid Suction (Suction Phase): As the gear rotates, operation begins. During this phase, the gears are positioned so that the teeth of each gear mesh near the inlet. As the gear rotates, a vacuum is created between the gear teeth, drawing fluid from the reservoir through the inlet into the pump.
Fluid Compression (Discharge Phase): As the gears continue to rotate, the meshing action of the gears traps fluid between the gear teeth and the pump casing. This trapped fluid is carried outside the gear and to the outlet. As the teeth mesh more closely, the volume of the fluid chamber between the gears decreases, compressing the fluid and increasing its pressure.
Fluid Drainage: Once the fluid reaches the outlet, it is drained from the pump and directed to the hydraulic system where it can perform useful work. The pressure produced by a pump depends on factors such as rotational speed, gear size, and fluid viscosity.
Advantages of gear hydraulic pumps:
Simple design: The design of the gear pump is relatively simple and easy to manufacture, install and maintain.
Cost Effectiveness: Due to their simplicity, gear pumps are generally less expensive compared to other types of hydraulic pumps.
High Efficiency: Gear pumps can achieve high volumetric efficiency, which means they can provide consistent fluid flow with minimal leakage.
Wide range of applications: Gear pumps are suitable for a variety of applications, including automotive, industrial and mobile hydraulic systems.
The characteristics of a gear pump mainly depend on its design and working principle. The following are the main features of gear pumps:
Positive Displacement: Gear pumps are positive displacement pumps, which means they deliver a fixed volume of fluid for each rotation of the gear. Gear pump characteristics ensure constant flow regardless of changes in pressure or viscosity.
Simple design: The structure of the gear pump is relatively simple, consisting of only a few basic components, such as gears, housings and ports. This simplicity makes them easy to manufacture, install and maintain.
High Efficiency: Gear pumps can achieve high volumetric efficiency, which means they move the majority of the fluid displaced by the gears. Its efficient design minimizes energy losses and maximizes hydraulic system performance.
Smooth operation: Gear pumps provide relatively smooth and pulsation-free fluid flow due to the continuous meshing action of the gears. This feature is beneficial for applications requiring precise fluid delivery.
Suitable for high-pressure applications: Gear pumps are capable of generating high fluid pressures, making them suitable for applications requiring high-pressure hydraulic systems.
Limited Suction Capacity: One limitation of gear pumps is their relatively low suction capacity compared to other pump types. In systems with significant suction lift or problems with air ingress, they may have difficulty initiating and maintaining suction.
Moderate noise levels: Although gear pumps are generally quieter than some other types of hydraulic pumps, they still produce moderate noise levels due to the meshing action of the gears. Proper maintenance and lubrication can help reduce noise levels.
