A tandem gear pump operates on the basic principle of positive displacement, where fluid is moved by trapping a fixed amount of it and then forcing (displacing) that trapped volume into the discharge pipe. The key difference between a tandem gear pump and a standard gear pump is that the tandem pump consists of two or more gear pump sections combined within a single housing, each driven by a common input shaft.
- Gears: Each section of the tandem gear pump contains a pair of gears, typically an external driving gear and an internal driven gear. These gears are crucial for creating the pumping action.
- Housing: The gears are enclosed within a precision-machined housing that helps maintain the tight tolerances required for efficient operation.
- Shaft: The common input shaft drives the gears in all sections of the tandem gear pump simultaneously, ensuring that each section operates in sync.
Working Steps of a Tandem Gear PUmp
- Rotation of the Input Shaft:
- The process begins with the input shaft, which is usually connected to a motor or an engine. As the shaft rotates, it turns the gears in each pump section.
- Fluid Intake:
- The rotation of the gears creates a low-pressure zone (vacuum) at the pump inlet. This vacuum draws hydraulic fluid from the reservoir into the pump housing.
- The fluid enters the spaces between the teeth of the gears and the walls of the housing.
- Trapping and Transporting Fluid:
- As the gears continue to rotate, they carry the trapped fluid around the outer circumference of the gear housing.
- The fluid is transported from the inlet side to the outlet side of the pump without allowing it to leak back due to the tight tolerances between the gear teeth and the housing.
- Fluid Discharge:
- When the gears reach the discharge side, the meshing of the gear teeth forces the trapped fluid out of the spaces and into the discharge pipe.
- The discharged fluid is then directed to the hydraulic system where it performs work (e.g., moving a cylinder, powering a motor).
- Independent Operation of Sections:
- In a tandem gear pump, each section operates independently, meaning it can deliver fluid at different flow rates and pressures.
- This allows the tandem pump to supply multiple hydraulic circuits from a single unit, with each circuit receiving the specific pressure and flow rate it requires.
Applications of the Tandem Gear Pump
- Multi-Circuit Hydraulic Systems: Tandem gear pumps are ideal for systems that require different flow rates and pressures for various functions, such as in construction machinery, agricultural equipment, and industrial machines.
- Space-Saving Designs: The ability to integrate multiple pump sections into a single unit allows for more compact hydraulic systems, saving space and reducing the overall complexity of the system.
In summary, the working principle of a tandem gear pump is based on the synchronized operation of multiple gear pump sections within a single housing. Each section draws in, traps, and displaces hydraulic fluid, enabling the pump to supply multiple circuits with different pressures and flow rates, all driven by a single input shaft. This makes tandem gear pumps highly efficient, versatile, and suitable for complex hydraulic applications.