Gear pumps are a type of positive displacement pump that use meshing gears to move fluid. They are commonly used in various applications, such as hydraulic systems, lubrication systems, and fuel transfer systems. There are mainly two types of gear pumps:
External Gear Pump: In an external gear pump, two gears with external teeth mesh together inside a housing or casing. The gears rotate in opposite directions, and the fluid is carried between the gear teeth and the pump casing. As the gears rotate, the fluid is trapped in the spaces between the teeth and the casing, and it is forced to move from the pump inlet to the outlet. External gear pumps are typically used for lower to medium flow rates and can handle a wide range of viscosities.
Internal Gear Pump: Internal gear pumps, also known as "gear-within-a-gear" pumps, consist of two gears—one larger and one smaller—meshed together inside a housing. The smaller gear is mounted eccentrically within the larger gear, causing the teeth of both gears to mesh. As the gears rotate, fluid is drawn into the pump between the teeth of the outer gear and the housing and then forced out as the teeth mesh together. Internal gear pumps are capable of handling a wide range of viscosities and can operate at high pressures. They are often used in applications requiring high precision and steady flow.
In both types of gear pumps, the fluid is positively displaced from the inlet to the outlet, providing a consistent flow rate regardless of pressure changes in the system. However, they may not be as efficient as some other pump types, and they may generate more noise due to gear meshing.
Additionally, gear pumps can be designed as:
Bi-rotational: The pump can operate in both directions of rotation, which can be advantageous for certain applications.
Uni-rotational: The pump operates in only one direction of rotation.
Fixed Displacement: The pump delivers a fixed amount of fluid per revolution, making it suitable for applications where a constant flow rate is required.
Variable Displacement: Some gear pumps can vary the amount of fluid delivered per revolution, allowing for flow rate adjustments. These are known as variable displacement gear pumps.
It's essential to select the right type of gear pump for a specific application based on flow rate requirements, fluid viscosity, pressure conditions, and other operational factors.
Post time: Jul-24-2023