# Analyze how the Variable Displacement Axial Piston Pump works

Due to the advancement of computing technology, numerical simulation of the complex dynamic phenomenon of variable displacement axial piston pump becomes possible. However, not all details are often included in a model. One of the explanations may be that the proportions of the different parts of the research are too large.

In the case of variable displacement axial piston pump, the difference between the size of the gap height and the difference between the diameter of the displacement chamber may reach three orders of magnitude, and the analysis results may be invalid due to unacceptable errors. The analysis result is unreliable.

## Ways to circumvent huge differences in scale

One way to circumvent the resistance of huge differences in scale is the multi-scale method. In this method, objects with very different scales are modeled separately, and personnel models are linked along side boundary conditions. This is how we model the gap flow of the lubrication variable displacement axial piston pump, which includes the energy equation in the model, because the viscosity of the fluid will significantly affect the flow. We show how numerical simulation can enhance the planning process of a completely unique high axial piston pump. The variable displacement axial piston pump may be a robot that converts energy into hydraulic energy. The hydraulic fluid flow it generates can overcome the resistance pressure generated by the load. There are several types of hydraulic pumps: gear pumps, piston pumps, rotary vane pumps and screw pumps. Piston pumps can be divided into axial pumps and radial pumps. The axial piston pump may have a swash plate with a variable swash plate angle or a swash plate pump.

## How to keep the flow rate at a preset level

The variable displacement axial piston pump with swash plate design is used in a hydraulic actuator composed of a pump and an electric motor, and runs in a circuit system. They are used to drive mobile equipment (such as combine harvesters) or rotating technical equipment (such as transport mixer drums, etc.).
The variable displacement axial piston pump is easy to control and relatively compact. The flow rate of the pump is proportional to the rotation speed of the engine block, and the displacement varies with the position of the swash plate. When the swash plate is tilted from its neutral position to the other direction, the flow direction is reversed. Modular control valve adjustment provides flexibility of control combination. Thanks to this system, the swash plate can be kept in the desired position, thereby keeping the flow rate at a preset level.

ER-Electro-hydraulic 3-position system. It is used to open-close-close-open the drive to the system. Usually equipped with maximum displacement control. HD-hydraulic proportional system. With the aid of a hydraulic indicator, the swashplate can be kept in the desired position. It is used on machinery that needs to continuously adjust the flow of variable displacement axial piston pump to cope with the workload faced by suspended or installed equipment. Thanks to the current intensity on the two proportional magnets, the displacement can be adjusted steplessly. The design of 90 and 112 ccm pumps can be combined in series.

## In conclusion

Applying CFD simulation to a PWK axial piston pump design process shows that it might be useful in situations when analytical solution is complicated or unavailable. Additionally, the analysis of flow in gaps of various configurations revealed the sensible advantage of applying a numerical analysis. For obvious reasons a replacement design of the axial pump has got to be believe virtual prototyping which is especially important when dynamic phenomena are considered and therefore the transient simulation has got to be performed. Often coefficients describing fluid flow through the analytical formulas are inaccurate and only due to numerical simulation precise assessment of the flow parameters are often obtained. Numerical simulation of flow in lubrication gaps poses severe challenges closely linked with the spatial scale of the matter , also like the complexity of the natural phenomenon . it’s quite easy to model one aspect of the piston-cylinder configuration, namely the case—when both objects are concentric. Then the axisymmetric model of the lubrication gap are often applied. things gets complicated when lateral loading on the piston is to be taken into effect and a piston is forced to assume an eccentric or skewed position with reference to a cylinder. That opens thanks to the answer of the Reynold’s equation by iterative methods.

In order to simulate the complete coupled phenomenon of flow during a lubrication gap more effort would need to be expended than described during this paper. And such analysis would need to include fluid–structure interaction and warmth transfer. Such task is doable specially with the utilization of approach presented above—when multiscaling is taken under consideration and a worldwide problem might be transferred into an area one.

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