The Torque on the Swashplate of Axial Piston Variable Displacement Pumps With Conical Cylinder Blocks

2018 ◽  
Author(s):  
Yapeng Xu ◽  
Kai Guo ◽  
Jianfeng Li ◽  
Keyu Wang
Keyword(s):  
Angular Velocity ◽  
Analytical Solution ◽  
Centrifugal Force ◽  
Dynamic Models ◽  
Chamber Pressure ◽  
Load Torque ◽  
Load Pressure ◽  
Variable Displacement ◽  
Axial Piston ◽  
Variable Displacement Pumps

In this paper, the load torque on the swashplate of axial piston variable displacement pumps with conical cylinder blocks is studied. At present, general analytical solution for the load torque of axial piston variable displacement pump is not available, which makes the dynamic analysis and controller design an uneasy work. The main contribution of this paper is that the analytical solution of the swashplate torque caused by piston inertia and centrifugal force was derived. First, based on the piston acceleration and centrifugal force, the piston kinematic and dynamic models were developed, the analytical solution of the swashplate torque caused by piston inertia and centrifugal force was derived. In addition, the piston chamber pressure dynamics were established, the pressure distribution in the cylinder bore and the load torque of the swashplate under different working conditions were obtained. Finally, the relationship between the swashplate average load torque and the swashplate angle, swashplate angular velocity, pump load pressure and the pump input shaft velocity was uncovered. It is shown that the swashplate angle has greater influence on the load torque when the pump load pressure is higher, besides, it is interesting to observe that the swashplate angular velocity has a damping influence upon swashplate dynamics which helps to stabilize the swashplate during pump displacement regulation transients.

Leakage Based Condition Monitoring and Pressure Control of the Swashplate Axial Piston Pump

2019 ◽  
Author(s):  
Neeraj Kumar ◽  
Bikash Kumar Sarkar ◽  
Subhendu Maity
Keyword(s):  
Hydraulic System ◽  
Pressure Control ◽  
Piston Pump ◽  
Chamber Pressure ◽  
Leakage Flow ◽  
Axial Piston Pump ◽  
Highly Nonlinear ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Axial Piston

Abstract This research mainly focused on the axial piston variable displacement pump, which is the most important part of the fluid power system. The variable displacement axial piston has been found as versatile and flexible for electro-hydraulic applications. Heavy industries such as automobile, aircraft, and mining use an axial piston pump due to its high power to weight ratio, continuous variable power transmission, low inertia, self-lubricating properties, and good controllability. The main challenges with the hydraulic system are highly nonlinear, leakages, unknown external disturbance, etc. The mathematical model of the variable displacement pump along with swashplate control has been developed. The model is used to identify the pump health condition with pressure and flow measurement, i.e., ripple pattern. The pressure and flow ripple will vary from the regular pattern due to wear and tear, i.e., increased leakage flow. The main source of the increase in leakage flow is due to wear in piston and cylinder bore. The piston chamber pressure, kinematical flow, and discharge area model of the pump has been validated with the existing results. The pump pressure control is very much essential for the enhancement of the performance of the electro-hydraulic system. In the present study, a conventional PID controller has been used as a backup to maintain system performance within the permissible faults. The electro-hydraulic system has been employed for swash-plate control of the pump to obtain desire pressure flow at the exit of the pump. MATLAB Simulink has been used for the simulation study of the pump.

Dimensionless Design of Variable Displacement Pumps

2009 ◽  
Author(s):  
Scott Manwaring ◽  
Andrew Alleyne
Keyword(s):  
Dimensional Analysis ◽  
Biological Systems ◽  
Design Guidelines ◽  
Industry Data ◽  
Functional Relationships ◽  
Variable Displacement ◽  
Engineered Systems ◽  
Independent Design ◽  
Axial Piston ◽  
Variable Displacement Pumps

External market forces constrain the design of engineered systems in much the same way that environmental conditions constrain the evolution of biological systems. Dimensional analysis is used to find functional relationships within biological systems and in turn can be used determine design relationships for engineered ones. This work applies these concepts to axial-piston swashplate variable displacement pumps. After presenting a pump model suitable for dimensional analysis, the necessary transformations are performed to create a pump model with completely dimensionless parameters and dynamics. Using a set of industry data, scale independent design information is extracted from successful industry pumps. This information is used to develop dimensionless design guidelines and strategies which allow for the specification of new designs dynamically similar to the original successful products.

Energy-saving design of variable-displacement bi-directional pump-controlled electrohydraulic system

2020 ◽  
pp. 095965182097389
Author(s):  
Samir Kumar Hati ◽  
Nimai Pada Mandal ◽  
Dipankar Sanyal
Keyword(s):  
Energy Saving ◽  
Absolute Error ◽  
Fast Response ◽  
Maximum Energy ◽  
Radial Clearance ◽  
Simulation Based Design ◽  
Simulation Based ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Axial Piston

Losses in control valves drag down the average overall efficiency of electrohydraulic systems to only about 22% from nearly 75% for standard pump-motor sets. For achieving higher energy efficiency in slower systems, direct pump control replacing fast-response valve control is being put in place through variable-speed motors. Despite the promise of a quicker response, displacement control of pumps has seen slower progress for exhibiting undesired oscillation with respect to the demand in some situations. Hence, a mechatronic simulation-based design is taken up here for a variable-displacement pump–controlled system directly feeding a double-acting single-rod cylinder. The most significant innovation centers on designing an axial-piston pump with an electrohydraulic compensator for bi-directional swashing. An accumulator is conceived to handle the flow difference in the two sides across the load piston. A solenoid-driven sequence valve with P control is proposed for charging the accumulator along with setting its initial gas pressure by a feedforward design. Simple proportional–integral–derivative control of the compensator valve is considered in this exploratory study. Appropriate setting of the gains and critical sizing of the compensator has been obtained through a detailed parametric study aiming low integral absolute error. A notable finding of the simulation is the achievement of the concurrent minimum integral absolute error of 3.8 mm s and the maximum energy saving of 516 kJ with respect to a fixed-displacement pump. This is predicted for the combination of the circumferential port width of 2 mm for the compensator valve and the radial clearance of 40 µm between each compensator cylinder and the paired piston.

scholarly journals Probability analysis of dynamical effects of axial piston hydraulic motor

2018 ◽  
Vol 157 ◽  
pp. 03016
Author(s):  
Alzbeta Sapietova ◽  
Vladimír Dekys ◽  
Milan Sapieta ◽  
Peter Sulka ◽  
Lukas Gajdos ◽  
...  
Keyword(s):  
Analytical Solution ◽  
Impact Force ◽  
Probability Analysis ◽  
Hydraulic Motor ◽  
Probabilistic Description ◽  
Probabilistic Solution ◽  
Input Variables ◽  
Axial Piston ◽  
Proper Operation

The paper presents an analysis of impact force on stopper screw in axial piston hydraulic motor. The solution contains probabilistic description of input variables. If the output parameters of probabilistic solution are compared with arbitrary values and values acquired by analytical solution, the probability of proper operation of the device can be evaluated.

An E/H Control Design for a Hydraulic Variable Displacement Axial Piston Motor

2011 ◽  
Author(s):  
Hongliu Du
Keyword(s):  
Adaptive Learning ◽  
Lower Cost ◽  
Learning Algorithm ◽  
Control Design ◽  
Test Results ◽  
Satisfactory Performance ◽  
Control Scheme ◽  
Variable Displacement ◽  
System Uncertainties ◽  
Axial Piston

A simple and novel speed control scheme for variable displacement motors has been developed under the consideration of some system uncertainties. Theoretical analysis and experimental test results have shown that the proposed control strategy is capable of driving the swashplate to track its desired trajectory with robust stability and satisfactory performance. An adaptive learning algorithm enables the controls to automatically adjust for uncertainties in the control bias current. Compared with its hydro-mechanical counterpart, the provided E/H control results in a hydraulic variable displacement motor with lower cost and better performance.

scholarly journals The friction torque characteristics of variable displacement type axial piston motors and their mathematical model.

1988 ◽  
Vol 19 (3) ◽  
pp. 242-248
Author(s):  
Hideki Yanada ◽  
Jyube Wu ◽  
Yoshihiro Kanamaru ◽  
Akira Hibi ◽  
Tsuneo Ichikawa
Keyword(s):  
Mathematical Model ◽  
Friction Torque ◽  
Variable Displacement ◽  
Axial Piston

scholarly journals Modeling and Designing a Hydrostatic Transmission With a Fixed-Displacement Motor

1998 ◽  
Vol 120 (1) ◽  
pp. 45-49 ◽  
Author(s):  
N. D. Manring ◽  
G. R. Luecke
Keyword(s):  
Order System ◽  
Axial Piston Pump ◽  
Third Order ◽  
Stability Range ◽  
Hydrostatic Transmission ◽  
Control Gain ◽  
Variable Displacement ◽  
Linearized System ◽  
The Stability ◽  
Axial Piston

This study develops the dynamic equations that describe the behavior of a hydrostatic transmission utilizing a variable-displacement axial-piston pump with a fixed-displacement motor. In general, the system is noted to be a third-order system with dynamic contributions from the motor, the pressurized hose, and the pump. Using the Routh-Hurwitz criterion, the stability range of this linearized system is presented. Furthermore, a reasonable control-gain is discussed followed by comments regarding the dynamic response of the system as a whole. In particular, the varying of several parameters is shown to have distinct effects on the system rise-time, settling time, and maximum percent-overshoot.

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