Pressure Compensator Design for a Swash Plate Axial Piston Pump

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
N. P. Mandal ◽  
R. Saha ◽  
S. Mookherjee ◽  
D. Sanyal
Keyword(s):  
Critical Role ◽  
Design Procedure ◽  
Swash Plate ◽  
Simulation Based Design ◽  
Displacement Pump ◽  
Popular Pressure ◽  
Variable Displacement ◽  
And Control ◽  
Spool Valve ◽  
Axial Piston

An in-line axial-piston swash-plate pump with pressure compensator is widely used for its fast speed of response and power economy. Although several simulation based design approaches exist to minimize issues like fluid-born noises, ample scope exists for more exhaustive design analysis. The most popular pressure compensator for a variable displacement pump with a spool valve actuating the control and bias cylinders has been taken up here. With an existing comprehensive flow dynamics model, an updated model for swiveling dynamics has been coupled. The dynamics also includes the force containment and friction effects on the swash plate. A design optimization has been accomplished for the pressure compensator. The target of the optimal design has been set as minimizing the transient oscillations of the swash plate, the compensator spool, pressures in the bias and control cylinders along with avoidance of both over-pressurization and cavitation in the bias cylinder. It has been found that the orifice diameters in the spring-side and at the metering port of the spool valve and in the backside of the bias cylinder have critical role in arriving at an optimum design. The study has led to a useful design procedure for a pressure compensated variable displacement pump.

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.

Virtually Variable Displacement Hydraulic Pump Including Compressability and Switching Losses

2006 ◽  
Author(s):  
Mark A. Batdorff ◽  
John H. Lumkes
Keyword(s):  
High Speed ◽  
Control Valve ◽  
Switching Control ◽  
Optimum Pressure ◽  
Fast Switching ◽  
Switching Losses ◽  
Swash Plate ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Axial Piston

Hydraulic pumps can be fixed or variable displacement. Fixed displacement pumps are typically smaller, lighter, less expensive, and can be of any design (gear, vane, axial piston, radial piston, ect.)[1]. Variable displacement pumps are often axial piston with an adjustable swash plate. A virtually variable displacement pump (VVDP) is a fixed displacement pump combined with a fast switching control valve that performs the same function as a variable displacement pump. This is done by always pumping full flow, but using the control valve to divert only a certain percentage of flow to the system, and the rest back to tank. A VVDP has several advantages over a traditional variable swash axial piston pump. First, the pump can be of any design, not just axial piston. Second, the flow control bandwidth can be much faster because it is only limited by the bandwidth of the fast switching control valve and system accumulator, not the bandwidth of a swash plate. Third, a VVDP pump can be more efficient because it can operate at its optimum pressure and flow setting. On the downside a VVDP will require a high speed valve. There are also added switching power losses due to constant metering over valves, compressing and decompressing hydraulic oil, and metering during transition between pumping to system and tank. This paper concentrates on modeling these three switching losses.

scholarly journals Pressure compensator design, simulation and performance evaluation of a variable displacement swash plate type axial piston pump

2021 ◽  
pp. 123-130
Author(s):  
Nitesh MONDAL
Keyword(s):  
Design Procedure ◽  
Maximum Flow ◽  
Piston Pump ◽  
Experimental Result ◽  
Axial Piston Pump ◽  
Output Pressure ◽  
Swash Plate ◽  
Variable Displacement ◽  
Axial Piston ◽  
Plate Type

This work presents a simple design procedure of a pressure compensator of a swash plate type variable displacement axial piston pump (VDAPP). The route of the work mainly focuses on static design through balancing the torque given by the pump pistons, rate cylinder and strok- ing cylinder on the swash plate during cut-in (maximum flow) and cut-off (minimum flow) pressure condition of the system with an objective of minimizing the output pressure ripples. The outcome in terms of pressure from the dynamic simulation of the designed compensator with pump has been compare with experimental result obtained from a reference commercial pump has compensator with duel spool. The model has been used for performance prediction for wide variations of the load valve area settings.

scholarly journals A Single Stage Spool Valve for the Pressure Compensator of a Variable Displacement Pump – Design, Dynamic Simulation and Comparative Study With A Real Pump

2021 ◽  
Author(s):  
Nitesh Mondal ◽  
Rana Saha ◽  
Dipankar Sanyal
Keyword(s):  
Comparative Study ◽  
Design Sensitivity ◽  
Single Stage ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Pump Design ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Spool Valve ◽  
Axial Piston

Abstract The study is focused on the design of a simplified spool valve to be incorporated in the pressure compensator of a variable displacement axial piston pump in order to perform a comparative study with a commercial pump having a two stage spool valve in its compensator. The design involves evaluation of the spool size and selection of spring from static equilibrium condition to satisfy cut-in and cut-off pressure. Following the development of dynamic model of the system, a design sensitivity analysis of the spool valve has been carried out through simulation to identify the critical sizes of the parameters, which affect the pump performance. By systematic design, it is possible to have a single stage spool valve controlled pressure compensator that can produce performance of the variable displacement axial piston pump at par with the similar commercially available pump.

Robust Nonlinear Control of a Novel Indexing Valve Plate Pump: Simulation Studies

2002 ◽  
Vol 124 (4) ◽  
pp. 613-616 ◽  
Author(s):  
X. Zhang ◽  
S. S. Nair ◽  
N. D. Manring
Keyword(s):  
Pressure Control ◽  
Plate Motion ◽  
Nonlinear Simulation ◽  
Response Characteristics ◽  
Model Free ◽  
Swash Plate ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Robust Adaptive ◽  
Improved Performance

A robust adaptive pressure control strategy is proposed for a novel indexing variable-displacement pump. In the proposed approach, parametric uncertainties and unmodeled dynamics are identified to the extent possible using a model free learning network and used to decouple the dynamics using physical insights derived from careful reduced order modeling. The swash plate motion control is then carefully designed to provide the desired pressure response characteristics showing improved performance with learning. The proposed control framework and designs are validated using a detailed nonlinear simulation model.

An Improved Alternative to the Three-Dimensional, Swash Plate Mechanism

1983 ◽  
Vol 105 (3) ◽  
pp. 468-470 ◽  
Author(s):  
T. E. Shoup ◽  
D. Chi
Keyword(s):  
Theoretical Analysis ◽  
Mechanism Design ◽  
Research Effort ◽  
Three Dimensional ◽  
Design Technique ◽  
Force Transmission ◽  
Swash Plate ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Crank Mechanism

This paper presents a theoretical analysis and a design technique for the use of a special type of adjustable spatial slider crank mechanism to replace the swash plate device commonly used as a variable displacement pump or compressor. This paper is an extension of a previous research effort utilizing the RSSP mechanism [7] and considers the influence of geometric proportions of a device on stroke size, velocity fluctuation, and force transmission effectiveness. The device is shown to have significant kinematic advantages over the traditional form of the swash plate mechanism. Design curves are presented and an example application is provided.

DYNAMIC LOADS ON THE DRIVE SHAFT BEARINGS OF A SWASH PLATE AXIAL PISTON PUMP WITH CONICAL CYLINDER BLOCK

2004 ◽  
Vol 27 (4) ◽  
pp. 309-318
Author(s):  
M.K. Bahr Khalil ◽  
J.V. Svoboda ◽  
R.B. Bhat
Keyword(s):  
The Body ◽  
Drive Shaft ◽  
Dynamic Loads ◽  
Cylinder Block ◽  
Axial Piston Pump ◽  
Static And Dynamic Characteristics ◽  
Swash Plate ◽  
Variable Displacement ◽  
Heavy Loads ◽  
Axial Piston

Variable displacement swash plate pumps are invariably used under conditions that involve heavy loads with variable flow demands. Swash plate pumps with conical cylinder blocks are now widely used in view of their good static and dynamic characteristics. However, drive shafts of these pumps experience dynamic loads due to the pressure forces transmitted through the body of the conical cylinder block to the supporting bearings. Dynamics of such rotating mechanism are quite interesting and should be considered in the design process of the drive shaft and the supporting bearings. A mathematical model is formulated for a 9-piston swash plate pump with conical cylinder block in order to evaluate the dynamic loads on the drive shaft. Results are presented and discussed.

The Research of Oil Pressure Fluctuation Influence to Rolling Mill Control Precision

2013 ◽  
Vol 330 ◽  
pp. 624-628
Author(s):  
Chun Ming Chen ◽  
Ya Jun Liu ◽  
Yun Xia Zhang ◽  
Dan Xia Guo
Keyword(s):  
Pressure Fluctuations ◽  
System Control ◽  
Hydraulic Control ◽  
Control Precision ◽  
Pressure Variable ◽  
Displacement Pump ◽  
Practical Engineering ◽  
Variable Displacement ◽  
Oil Source ◽  
And Control

Oil source made up of constant pressure variable displacement pump, accumulator, and pipeline is widely used to provide stable pressure for electro-hydraulic control system in practical engineering. Based on the experiment, the relationship between initial charging pressure & volume of the accumulator at inlet of the servo valve and control precision is analyzed in detail, and coupling rules between the load variation and the pressure fluctuations of oil-source are obtained, the rules can give reference for selecting initial charging pressure & volume of the accumulator according to the requirement of system control precision, which can further improve control precision and product quality by optimizing equipment parameters.

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