The Shaft Torque of a Tandem Axial-Piston Pump

2006 ◽  
Vol 129 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Noah D. Manring ◽  
Viral S. Mehta ◽  
Frank J. Raab ◽  
Kevin J. Graf
Keyword(s):  
Angular Position ◽  
Single Pulse ◽  
Torque Ripple ◽  
Piston Pump ◽  
Additional Parameter ◽  
Axial Piston Pump ◽  
Pump Design ◽  
Ripple Amplitude ◽  
Shaft Torque ◽  
Axial Piston

The objective of this study is to identify the best indexed position of two rotating groups within a tandem axial-piston pump for attenuating the torque ripple amplitude that is exerted on the shaft. By attenuating the torque ripple characteristics of the pump, other vibration aspects of the machine are also expected to be reduced. In particular, the objectives of this paper are aimed at reducing the noise that is generated by the pump. This paper begins by considering the theoretical torque ripple that is created by the discrete pumping elements of a single rotating group within an axial piston machine. From this analysis, an equation is produced that describes a single pulse for the torque ripple as a function of the average torque and the total number of pistons that are used within the rotating group. By superposing another rotating group on top of the first, and by indexing the angular position of one rotating group relative to the other, a second equation is produced for describing the theoretical torque ripple of a tandem pump design. This equation is also a function of the average shaft torque and the total number of pistons that are used within a single rotating group; however, an additional parameter known as the index angle also appears in this result. This index angle is shown to amplify or attenuate the amplitude of the torque ripple depending upon its value. From these results, it is shown that a proper selection of the index angle can reduce the torque ripple amplitude by as much as 75%.

Torque Ripple Attenuation of an Axial Piston Pump by Continuous Swash Plate Adjustment

2005 ◽  
Author(s):  
Viral S. Mehta ◽  
Noah D. Manring
Keyword(s):  
Noise Level ◽  
Torque Ripple ◽  
Primary Objective ◽  
Piston Pump ◽  
Control Law ◽  
Axial Piston Pump ◽  
Input Shaft ◽  
Swash Plate ◽  
Shaft Torque ◽  
Axial Piston

One of the major drawbacks of a hydraulic system is the disturbing noise generated by the hydraulic pump. Based on the accepted theory about noise generation in an axial piston pump, various studies suggesting modification of the port-plate relief groove geometry and addition of hydraulic attenuators have shown a limited success in reducing the noise. The noise level is still high and may not be acceptable for future applications. A recent industrial study shows that the noise apparently has relation with the torque acting on the input shaft of the axial piston pump. The primary objective of this paper is to describe a new method to reduce the noise level by varying the swash plate of the pump continuously to eliminate the torque ripple. The paper begins by deriving the equation of torque acting on the input shaft as a function of the average torque and the total number of pistons that are used within the rotating group. A control law is derived according to which if the swash plate is dithered, should give a constant shaft torque. By attenuating the torque ripple characteristics of the pump, other vibrational aspects of the pump are also expected to be reduced. The secondary objective of this paper is to present a Simulink® model of a nine piston pump to describe a functional pump. The swash plate control law earlier derived will be applied to this model to see the behavior of the output parameters like the shaft torque, output flow and pressure. The results will be investigated to see if any relationship exist between the pump torque ripple and pressure ripple, and the theory of pump noise attenuation by reduction in torque ripple will be corroborated.

A Novel Axial Piston Pump/Motor Principle With Floating Pistons: Design and Testing

2018 ◽  
Author(s):  
Liselott Ericson ◽  
Jonas Forssell
Keyword(s):  
Low Noise ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Pump Design ◽  
Main Challenge ◽  
Piston Seal ◽  
Displacement Angle ◽  
Type Machine ◽  
Expected Benefits ◽  
Axial Piston

This paper presents the first prototype of a novel axial piston pump/motor of slipper type. The pistons are floating in the cylinders and hence the name floating piston pump. The novel pump design fills a gap in the traditional pump design. The pump is made to fit the automobile requirements to use fluid power in a more prominent manner. One of the expected benefits of this design is its simplicity and therefore the machine does not require high manufacturing capabilities. The production cost is expected to be low. The machine is designed with high number of pistons, which leads to a pump/motor with low noise level. The displacement angle is small, 8 degrees, which leads to low piston speeds with its benefits. The main challenge in the design is the piston seal configuration. The seals will both, deform (ovality) and move in a circle relative to the pistons. The paper discusses design considerations and proposes a design. The efficiency measurement of the first prototype is in level of a series produced slipper type machine at its sweet spot.

Numerical Study Optimal Timing of the Axial Piston Pump

2011 ◽  
Author(s):  
Shusen Zhang ◽  
Noah D. Manring ◽  
Viral S. Mehta
Keyword(s):  
Numerical Study ◽  
Dynamic Pressure ◽  
Piston Pump ◽  
Optimal Timing ◽  
Axial Piston Pump ◽  
Pump Design ◽  
Inlet Port ◽  
Actual Design ◽  
Pressure Ripple ◽  
Axial Piston

In this paper, the theoretical optimal timing of the axial piston pump is first derived to confirm the analysis published by Professor Kevin Edge [1]. It is discovered that the optimal discharge port delay is different from the optimal inlet port delay. The dimensional analysis also shows that higher shaft angular velocity indicates less delay required in both discharge port and inlet port. Numerical studies show that optimal timing can reduce the dynamic pressure ripple greatly, but since it does not affect the kinematic component, it will not eliminate the entire pressure ripple. The optimal timing could also induce an increase in efficiency where the baseline pump design has cross-porting. However, there is certain tradeoff between pressure ripple reduction and efficiency consideration. Actual design consideration to affect independent timing of the portplate is not studied in this work.

Optimal Control Theory Applied to Pressure-Controlled Axial Piston Pump Design

1990 ◽  
Vol 112 (3) ◽  
pp. 475-481 ◽  
Author(s):  
S. J. Lin ◽  
A. Akers
Keyword(s):  
Optimal Control ◽  
Control Theory ◽  
Optimal Control Theory ◽  
Control Valve ◽  
Open Loop ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Response Curves ◽  
Pump Design ◽  
Axial Piston

This work presents a study of the applicability of optimal control theory to the design of a pressure regulator by use of an axial piston pump with a two-stage electrohydraulic servovalve. The control valve has been modeled and an optimal control law has been formulated. The time response curves due to a step input in flow rate to the pump have been obtained for the open loop and the for the optimal control system. An examination of the results has shown that the performance, in terms of pressure peaks and frequency during recovery to the flow disturbance, is significantly improved over that obtained when a single-stage valve is used.

Load and Stress Analysis for the Swash Plate of an Axial Piston Pump/Motor

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
M. Z. Norhirni ◽  
M. Hamdi ◽  
S. Nurmaya Musa ◽  
L. H. Saw ◽  
N. A. Mardi ◽  
...  
Keyword(s):  
Hybrid Vehicles ◽  
Piston Pump ◽  
Control Force ◽  
Axial Piston Pump ◽  
Closed Loop System ◽  
Element Analysis ◽  
Pump Design ◽  
Braking System ◽  
Swash Plate ◽  
Axial Piston

In an axial piston pump design, the swash plate plays an important role in controlling the displacement of the pump, especially in a closed loop system. In this paper, the axial piston pump is incorporated into the design of a hydraulic regenerative braking system for hybrid vehicles. The pump in this configuration should function in dual mode, as a pump and as a motor. For this to occur, the swash plate should swing in two opposite directions. The swash plate presented in this paper is designed for stability and ease of control. Analytical analysis of torque and forces were conducted using MATLAB software to verify the motion of the swash plate. Furthermore, finite element analysis was also carried out to evaluate the rigidity and stress in the system. The analytical evaluation has shown that as the swash plate angle increases, the required control force and torque increase almost linearly. However, the change of the plate angle was found to have no effect on the force exerted on the X-axis and the torque exerted on the Z-axis.

Thermodynamic characteristics research of a water lubricating axial piston pump

2020 ◽  
Vol 234 (19) ◽  
pp. 3873-3889 ◽  
Author(s):  
Donglin Li ◽  
Geqiang Li ◽  
Jianhai Han ◽  
Yinshui Liu ◽  
Defa Wu
Keyword(s):  
Steady State ◽  
Water Temperature ◽  
Thermodynamic Model ◽  
Thermodynamic Characteristics ◽  
Piston Pump ◽  
Extreme Conditions ◽  
Axial Piston Pump ◽  
Pump Design ◽  
Cooling Design ◽  
Axial Piston

A water lubricating axial piston pump (WLAP) is one of the key components in water hydraulic systems. However, the characteristics of water, including low viscosity, strong corrosiveness, and easy vaporization, results in the increase of friction and wear of pairs, and the increase of temperature. Compared with oil pumps, the thermodynamic characteristic of WLAP is more serious. In this paper, the integrated thermodynamic model of WLAP, which includes heat generation of pairs and heat conduction of water and air, is established to improve pump design. The calculation results show that the water temperature of WLAP exceeded 90 ℃, and the pump could not work normally in extreme conditions (the inlet water temperature and ambient temperature are both 50 ℃). Consequently, a cooling design of WLAP, which circulates the inlet water in the pump chamber, is carried out. Then, the thermodynamic model was modified. Based on this model, the temperature rise characteristics and heat dissipation characteristics of the WLAP are analyzed. The steady-state water temperature of pump shell under extreme conditions is obtained. The temperature sensors and a thermal imaging were used to measure the temperatures of the WLAP. The results indicate that the water temperature of WLAP decreases significantly. The difference of the steady-state temperature of WLAP between simulation and experiment is less than 4 ℃, and its temperature distribution is uniform. Therefore, the cooling design of WLAP is effective and it can work normally under the maximum speed and pressure in extreme conditions.

Kinematics Modelling and Simulation of Aero-Engine Fuel Piston Pump

2014 ◽  
Vol 680 ◽  
pp. 299-302
Author(s):  
Jiang Feng Fu ◽  
Hua Cong Li ◽  
Jia Li ◽  
Shu Hong Wang
Keyword(s):  
Displacement Velocity ◽  
Piston Pump ◽  
Engine Fuel ◽  
Axial Piston Pump ◽  
Spherical Coordinate ◽  
Pump Design ◽  
Aero Engine ◽  
Axial Piston ◽  
Kinematics Parameters ◽  
Parameters Calculation

Kinematics parameters calculation is the basis of piston pump design and performance analysis. Taking an axial piston pump with incline piston and spherical swash plate as the research object, Aimed at the deficiency of current formula for calculating piston pump kinematics parameters which included displacement, velocity and acceleration. In this paper, according to piston pump part motion geometry relationship, a correction kinematics algorithm is deduced by using the the spherical coordinate and cartesian coordinate transformation method, the analyse method and deduction procedure ensure the new calculating formula are precise in theory. Applying the calculating formula to an aero engine fuel axial piston pump, results show that. The displacement, velocity, acceleration according to the kinematics principle of piston pump, it can be used in the kind of piston pump kinematics parameters calculation and current calculating method evaluation.

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.

Fast scaling approach based on cavitation conditions to estimate the speed limitation for axial piston pump design

2021 ◽  
Author(s):  
Qun Chao ◽  
Jianfeng Tao ◽  
Junbo Lei ◽  
Xiaoliang Wei ◽  
Chengliang Liu ◽  
...  
Keyword(s):  
Piston Pump ◽  
Axial Piston Pump ◽  
Pump Design ◽  
Axial Piston
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