A11V Axial Piston Pump in Tandem with a Gear Pump
I. Overview
The tandem configuration of an A11V axial piston pump with a gear pump is a common setup in hydraulic systems. This combination integrates the respective advantages of the two pumps to meet the diverse requirements for flow rate, pressure, and overall system performance under specific operating conditions.
II. Characteristics of the Two Pumps
(A) A11V Axial Piston Pump
1. High - Pressure Output Capability: The A11V axial piston pump is typically capable of generating high working pressures. This is attributed to its unique operating principle, where pistons reciprocate within the cylinder block. The pistons move in a straight - line motion inside the cylinder bores, and the suction and discharge of oil are achieved through the swinging of the swashplate or the inclined shaft. This structure enables it to withstand large loads and provide stable pressure to the system. It is suitable for hydraulic systems requiring high pressure, such as heavy - duty machinery and construction equipment.
2. Flow Rate Adjustability: By changing the inclination angle of the swashplate or the inclined shaft, the pump's displacement can be conveniently adjusted, thus enabling precise control over the output flow rate. This flow - rate adjustability allows the A11V axial piston pump to adapt to varying flow - rate demands under different operating conditions, enhancing the system's flexibility and efficiency.
3. High Efficiency: Within its normal operating range, the A11V axial piston pump exhibits relatively high volumetric and mechanical efficiencies. High volumetric efficiency means that the pump has minimal leakage losses during the oil - conveying process, enabling more efficient conversion of mechanical energy into hydraulic energy. High mechanical efficiency indicates low mechanical friction losses during the pump's operation, reducing energy waste.
(B) Gear Pump
1. Simple and Compact Structure: A gear pump mainly consists of two intermeshing gears and a pump body. Its structure is relatively simple, with a small volume and light weight. This gives it significant advantages in terms of installation and maintenance, especially in hydraulic systems with limited space.
2. Low Cost: Due to its simple structure and relatively mature manufacturing process, the cost of a gear pump is usually low. This makes it an economical choice in applications where cost - sensitivity is a concern.
3. Strong Self - Priming Capability: The gear pump can automatically suck in oil during startup without the need for additional auxiliary devices, demonstrating strong self - priming capability. This feature gives the gear pump an advantage in systems with unstable oil supply or those requiring frequent starts and stops.
III. Advantages of the Tandem Combination
(A) Flow Rate Superposition
When the A11V axial piston pump and the gear pump are connected in tandem, the total flow rate of the system is equal to the sum of the flow rates of the two pumps (under ideal conditions where leakage is neglected). This flow - rate superposition effect can meet the system's demand for a large flow rate. For example, in hydraulic actuator - driven systems that require rapid movement, the tandem combination can provide sufficient oil flow rate to ensure the fast and smooth movement of the actuators.
(B) Pressure Adaptability
The A11V axial piston pump is responsible for providing the high pressure required by the system, while the gear pump can play a role in auxiliary oil supply and pressure stabilization to a certain extent. When there are pressure fluctuations in the system, the gear pump can compensate for the pressure to some extent through its flow - rate regulation characteristics, making the system pressure more stable. For instance, when the system load suddenly increases, causing a pressure drop, the gear pump can provide additional flow rate to alleviate the pressure drop trend and ensure the normal operation of the system.
(C) System Flexibility
This tandem combination allows for flexible adjustment of the operating states of the two pumps according to actual operating conditions. For example, when the system's flow - rate demand is low, only the gear pump can be started to reduce energy consumption. When high pressure and a large flow rate are required, both pumps can be started simultaneously to meet the system's working requirements. This flexible operating mode can improve the system's energy utilization efficiency and reduce operating costs.
IV. Potential Problems and Solutions in the Tandem Combination
(A) Pressure Distribution Problem
In the tandem combination, the two pumps need to withstand different pressures. The A11V axial piston pump usually bears a relatively high working pressure, while the gear pump bears a lower pressure. If the pressure distribution is unreasonable, it may cause damage to the gear pump due to excessive pressure.
Solution: Install appropriate pressure - regulating valves and pressure - reducing valves in the system to ensure that the pressure borne by the gear pump is within its rated working pressure range. For example, a pressure - reducing valve can be installed at the outlet of the gear pump to control the pressure below a safe value.
(B) Flow Rate Matching Problem
There may be differences in the flow - rate characteristics of the two pumps. If the flow rates are not matched, it may lead to unstable system pressure or flow rate fluctuations.
Solution: Use precise flow - rate control and regulation devices, such as proportional valves and flow - control valves, to adjust and match the flow rates of the two pumps in real - time. At the same time, when selecting the pump models and specifications, fully consider the system's flow - rate requirements and the flow - rate characteristics of the two pumps, and try to choose pumps with similar flow - rate characteristics for combination.
(C) Leakage Problem
In the tandem combination, leakage is prone to occur at the connection parts between the pumps and the sealing parts of the pumps themselves. This not only affects the system's flow rate and pressure but may also cause oil contamination.
Solution: Use high - quality seals and connectors to ensure the sealing performance of the connection parts. Regularly maintain and inspect the system to promptly detect and handle leakage problems. In addition, leakage detection devices can be installed in the system to monitor the system's leakage status in real - time.
V. Application Scenarios
(A) Construction Machinery
In excavators, loaders, and other construction machinery, the hydraulic system needs to meet both high - flow and high - pressure requirements simultaneously. For example, during the movement of the excavator's boom, arm, and bucket, both rapid motion response (high - flow demand) and the ability to overcome large loads (high - pressure demand) are required. The tandem combination of the A11V axial piston pump and the gear pump can well meet these requirements, improving the work efficiency and performance of construction machinery.
(B) Marine Hydraulic Systems
The hydraulic equipment on ships, such as steering gears and windlasses, usually needs to operate in complex marine environments. The tandem pump system can provide stable pressure and flow rate to ensure the reliable operation of the ship's hydraulic equipment. At the same time, by flexibly adjusting the operating states of the pumps, it can adapt to the ship's needs under different operating conditions and reduce energy consumption.
(C) Metallurgical Equipment
In metallurgical production, some large hydraulic presses and rolling mills require hydraulic systems with high pressure and a large flow rate to drive them. The tandem combination of the A11V axial piston pump and the gear pump can meet the strict requirements of these equipment for hydraulic systems and ensure the smooth progress of production.
In conclusion, the tandem combination of the A11V axial piston pump and the gear pump has numerous advantages in hydraulic systems. However, in practical applications, attention should be paid to solving the potential problems that may arise to fully utilize its performance and meet the requirements under different operating conditions.
