Benefits of a Fixed-Displacement Hydraulic Pump

Benefits of a Fixed-Displacement Hydraulic Pump

When seeking a hydraulic pump solution for a hydraulic system, it is essential to carefully assess the appropriate pump type and possess a fundamental understanding of hydraulic principles and pump functionality. Hydraulic systems rely on pressurized fluid to generate force, achieved by converting mechanical energy into hydraulic energy through hydraulic pumps, which results in positive displacement downstream.

For instance, if the application involves raising and lowering pallets with a forklift, a crucial decision must be made between an "open-loop" or "closed-loop" system. In a "closed-loop" system, the fluid travels directly from the pump to the motor and back to the pump. Conversely, in an "open-loop" system, the fluid is drawn from a reservoir or tank, pumped to a control valve, utilized for operating services, and then returned to the tank.

Two prevalent types of pumps are fixed displacement pumps and variable displacement pumps. Fixed-displacement pumps are well-suited for tasks requiring a constant pressure for work completion. For example, a 30-cc pump will rotate 30 times, delivering 30 ml of hydraulic fluid through the system, maintaining a constant pressure and flow rate regardless of usage or system conditions. If a lower flow rate is needed, a variable displacement pump or flow diversion can be employed. Popular designs of fixed-displacement pumps include the bent-axis piston pump and the gear pump, with the bent-axis piston pump offering higher-pressure capabilities compared to a gear pump.

Fixed-displacement pumps offer advantages such as cost-effectiveness, ease of maintenance, and simpler design, making them suitable for processes demanding a consistent flow rate. However, it is crucial to select the correct size fixed-displacement pump, as their pressure and flow rates cannot be adjusted, unlike variable-displacement pumps.

In contrast, variable displacement pumps allow for electronic, mechanical, or hydraulic adjustment of fluid flow rates, depending on the specific pump type used, such as vane pumps, axial piston pumps, etc. The internal design of the pump, such as the bore area and stroke length of the pistons, determines the variable displacement technique. Control pistons inside the pump act as relief valves, regulating pressure by adjusting the stroke length as needed.

Variable displacement pumps offer several advantages beyond flow rate control, including more intricate designs for complex hydraulic systems. They can be custom-designed to precise specifications, providing greater adaptability for controlling and adjusting fluid flow rates across various applications.

In conclusion, depending on specific requirements, both fixed-displacement pumps and variable-displacement pumps offer distinct advantages. For further guidance on selecting the best pump or additional hydraulic system solutions, please feel free to contact Cascade Industrial Services Corp at (909) 923-8333 Ext#201.