scholarly journals Effect of clearance on volumetric efficiency in 2D piston pumps

2021 ◽  
Vol 13 (10) ◽  
pp. 168781402110477
Author(s):  
Yu Huang ◽  
Jian Ruan ◽  
Chuan Ding ◽  
Sheng Li
Keyword(s):  
Rotational Speed ◽  
Mechanical Efficiency ◽  
Volumetric Efficiency ◽  
Experimental Results ◽  
Reciprocating Motion ◽  
Load Pressure ◽  
Axial Piston Pumps ◽  
The Difference ◽  
Axial Piston ◽  
Two Degree Of Freedom

In order to solve the limitations of the friction pairs in axial piston pumps on rotational speed and mechanical efficiency, a 2D piston pump whose 2D piston has two-degree-of-freedom motions of rotation and reciprocating motion was proposed by the author team. The volumetric efficiency of 2D pumps predicted by the original volumetric efficiency model is higher than the experimental results. A new mathematical model of the volumetric efficiency is researched by considering effect of clearance between the cone roller and the guiding rail. In previous studies, the volumetric losses of the 2D pump were considered to be composed of leakage and compressibility loss. However, it is found that the effect of the clearance on the volumetric efficiency in 2D pumps is greater than that of leakage and compressibility loss. The experimental results show that the difference between the prediction of the new model and the volumetric efficiency of the tested pump with 0.19 mm clearance is reduced from 8% to 1.5% comparing with the original model. The volumetric efficiency of the tested pump without the clearance is 96.5% at 5000 rpm rotational speed and 8 MPa load pressure.

scholarly journals Research on the Volumetric Efficiency of 2D Piston Pumps with a Balanced Force

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4796
Author(s):  
Yu Huang ◽  
Jian Ruan ◽  
Yong Chen ◽  
Chuan Ding ◽  
Sheng Li
Keyword(s):  
Mathematical Model ◽  
Rotational Speed ◽  
Sliding Friction ◽  
Friction Pair ◽  
Weight Ratio ◽  
Volumetric Efficiency ◽  
Load Pressure ◽  
Axial Piston Pumps ◽  
Working Principle ◽  
The Mathematical Model

Axial piston pumps with high rotational speeds are required in many fields to increase the power-to-weight ratio. However, three main sliding friction pairs in the pump restrict the increase in rotational speed. To solve this problem, we propose a 2D piston pump with a balanced force that contains a sliding friction pair. Firstly, the mechanical structure and working principle of the pump are described. Then, the pump volumetric efficiency is studied by mathematical modeling, and volumetric losses containing backflow and leakage are analyzed and discussed from the perspectives of load pressure and rotational speed. A test bench that verifies the mathematical model is built to measure the volumetric efficiency of the tested pump. We have found that the increase in rotational speed can help to increase the pump volumetric efficiency, and the mathematical model is consistent with the tested data for 1000 rpm but demonstrates a remarkable difference from the tested data for 3000 rpm. Thus, the temperature field of the pump and the viscosity-temperature characteristics of the oil must be taken into account to increase volumetric efficiency further.

Improving the Volumetric Efficiency of the Axial Piston Pump

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Shu Wang
Keyword(s):  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Valve Plate ◽  
Piston Pump ◽  
Efficient Design ◽  
Axial Piston Pumps ◽  
Definition Of ◽  
Engineering Practices ◽  
First Time ◽  
Axial Piston

The volumetric efficiency is one of the most important aspects of system performance in the design of axial piston pumps. From the standpoint of engineering practices, the geometric complexities of the valve plate (VP) and its multiple interactions with pump dynamics pose difficult obstacles for optimization of the design. This research uses the significant concept of pressure carryover to develop the mathematical relationship between the geometry of the valve plate and the volumetric efficiency of the piston pump. For the first time, the resulting expression presents the theoretical considerations of the fluid operating conditions, the efficiency of axial piston pumps, and the valve plate designs. New terminology, such as discrepancy of pressure carryover (DPC) and carryover cross-porting (CoCp), is introduced to explain the fundamental principles. The important results derived from this study can provide clear recommendations for the definition of the geometries required to achieve an efficient design, especially for the valve plate timings. The theoretical results are validated by simulations and experiments conducted by testing multiple valve plates under various operating conditions.

scholarly journals Research on the Mechanical Efficiency of High-Speed 2D Piston Pumps

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 853 ◽  
Author(s):  
Yu Huang ◽  
Jian Ruan ◽  
Chenchen Zhang ◽  
Chuan Ding ◽  
Sheng Li
Keyword(s):  
Friction Coefficient ◽  
High Speed ◽  
High Pressures ◽  
Weight Ratio ◽  
Rolling Friction ◽  
Mechanical Efficiency ◽  
Load Pressure ◽  
Axial Piston Pumps ◽  
Series Of Experiments ◽  
Rolling Friction Coefficient

Since many studies on axial piston pumps aim at enhancing their high power-weight ratio, many researchers have focused on the generated mechanical losses by the three friction pairs in such pumps and attempted to diminish them through abundant and new structural designs of the pump’s components. In this paper, a high-speed 2D piston pump is introduced and its architecture is specifically described. Afterward, a mathematical model is established to study the pump’s mechanical efficiency, including the mechanical losses caused by the viscosity and stirring oil. Additionally, in this study the influences of the rotational speed, the different load pressures, and the rolling friction coefficient between the cone roller and the guiding rail are considered and discussed. By building a test rig, a series of experiments were carried out to prove that the mechanical efficiency was accurately predicted by this model at low load pressures. However, there was an increasing difference between the test results and the analytical outcomes at high pressures. Nevertheless, it is still reasonable to conclude that the rolling friction coefficient changes as the load pressure increases, which leads to a major decrease in the mechanical efficiency in experiments.

Applicability of Pump Models for Varying Operational Conditions

2003 ◽  
Author(s):  
Heikki O. J. Kauranne ◽  
Jyrki T. Kajaste ◽  
Asko U. Ellman ◽  
Matti T. Pietola
Keyword(s):  
Rotational Speed ◽  
Operating Conditions ◽  
Fluid Temperature ◽  
Limited Information ◽  
Operational Conditions ◽  
Axial Piston Pumps ◽  
Pump Construction ◽  
Temperature And Pressure ◽  
Axial Piston ◽  
Type Pressure

It is commonly known that the characteristics of a fluid power pump depend on pump type, pressure, rotational speed and displacement. But in addition to these, also all the other parameters or factors associated with the operating conditions may have a significant effect on the characteristics. The most important of these are the pump construction and size, operating point temperature and the characteristics of the oil, which also depend on temperature and pressure. The aim of this study is to show the effects that the varying operational conditions have on the characteristics of a axial piston pump, to compare the measured characteristics with other published characteristics of axial piston pumps and to study the capability of pump models to represent these characteristics. The results include information of the effects of fluid temperature, type of fluid and the setting value of the displacement on the pump characteristics along with the effects of pressure and rotational speed. The sensitivity of the pump to each of the parameters is discussed. The effect of limited information of pump characteristics on the reliability of simulation results is studied using the Schlo¨sser models.

Rotational Speed and Noise Level due to Distribution Oil Window Size of Three Type Pumps

2010 ◽  
Vol 29-32 ◽  
pp. 1246-1251
Author(s):  
De Sheng Wen ◽  
Zhi Li Wang ◽  
Shi Jun Lv ◽  
Jiang Bo Sun ◽  
Li Bin Du
Keyword(s):  
Rotational Speed ◽  
Noise Level ◽  
High Efficiency ◽  
Window Size ◽  
Hydraulic Pump ◽  
Axial Piston Pumps ◽  
Invention Patent ◽  
National Patent ◽  
Axial Piston ◽  
Level Analysis

In this paper, a new hydraulic pump was presented, called KZB pump which has obtained the national patent of invention (patent number: 85103289.3). Originally comes from CY series pumps that are common used at present, KZB pump shows many advantages, such as high pressure, high efficiency, and long service life etc. This paper focuses on the rotational speed and noise level analysis of this new pump. Firstly, we described the configuration of both semi-open and full-open axial piston pumps in detail, which both of them were all new pumps and the later was also called KZB pump. Next, we investigated the distribution oil window size that influences the pump's rotational speed and noise level mostly by mathematical analysis. Finally, the analysis and comparisons of the rotational speed and noise level performances for the three type pumps which mentioned above were made. It is proved through the test that under the same working conditions KZB pump has made great advanced in controlling noise and having lower self-absorption rotational speed compared with the other type pumps.

scholarly journals Research on the Volumetric Efficiency of a Novel Stacked Roller 2D Piston Pump

Machines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 128
Author(s):  
Chenchen Zhang ◽  
Jian Ruan ◽  
Tong Xing ◽  
Sheng Li ◽  
Bin Meng ◽  
...  
Keyword(s):  
Friction Pair ◽  
Research Work ◽  
Flow Distribution ◽  
Volumetric Efficiency ◽  
Piston Pump ◽  
The Novel ◽  
Load Pressure ◽  
Output Flow ◽  
Variation Curve ◽  
Axial Piston

In order to improve the volumetric efficiency of the axial piston pump, this paper proposes a novel stacked roller 2D piston pump. It utilizes the alternate communication between the distribution cylinder and the oil intake and discharge ports of the housing to realize the flow distribution. While removing the independent flow distribution mechanism of the traditional piston pump, the leakage loss at the distribution friction pair can be reduced to improve the volumetric efficiency. Based on the flow distribution principle, an analytical model of the volumetric efficiency of the stacked roller 2D piston pump was established. Then, a co-simulation model of the whole pump was built using both the Simulink and AMESim software. The variation curve of output flow and leakage flow under different load pressures and rotational speeds was obtained, as well as the influence of backflow, axial leakage, and circumferential leakage on the volumetric efficiency. On this basis, a prototype of the stacked roller 2D pump was designed and manufactured in order to measure the output flow under different load pressures and rotational speeds, and a dedicated test bench was established. The experimental results are consistent with the simulation results; when the rotational speed is 6000 rpm and the load pressure is 5 MPa, the volumetric efficiency of the prototype pump can reach 98.6%. The research work validates that the novel stacked roller 2D piston pump has high volumetric efficiency.

Design and research of 2D piston pumps with a stacked cone roller set

2021 ◽  
pp. 095440622110282
Author(s):  
Heyuan Wang ◽  
Chuan Ding ◽  
Yu Huang ◽  
Sheng Li ◽  
Jian Ruan
Keyword(s):  
Theoretical Analysis ◽  
Rolling Friction ◽  
Mechanical Efficiency ◽  
Piston Pump ◽  
Test Results ◽  
Oil Viscosity ◽  
Load Pressure ◽  
New Type ◽  
The Difference ◽  
Enclosed Chamber

A new type of two-dimensional (2D) piston pump with a stacked cone roller set was introduced to eliminate the influence of the gap between the guiding rail and the cone roller. First, the structure and working principle of the 2D piston pump were studied; then, a corresponding mathematical model which considered the oil viscosity and oil churning loss caused by the rotation of the guiding rail in the enclosed chamber was established to examine the volumetric and mechanical efficiency of the 2D piston pump. The effects of different speeds, load pressures, and rolling friction coefficients between the guiding rail and the cone rollers on the efficiency were considered. During the test, when the speed was 6000 r/min and the load pressure was 6 MPa and 8 MPa, the volumetric efficiency reached 98.3% and 96.8%, respectively, basically consistent with the theoretical analysis. Because the temperature rise of the tested pump caused the oil viscosity and the eccentricity of the piston and piston rings increased the leakage, the test result was slightly lower than that of the theoretical analysis. When the speed was 1000 r/min and the load pressure was 5 MPa, the mechanical efficiency was 69.3%, and the mechanical efficiency model was consistent with the test results. However, with the increase in speed and load pressure, the difference between the test results and theoretical analysis results increased because the supporting force of the cone roller on the guiding rail increased, increasing the rolling frictional losses.

Numerical simulation and experimental performance research of cylindrical vane pump

2021 ◽  
pp. 095440622110200
Author(s):  
Yiqi Cheng ◽  
Xinhua Wang ◽  
Waheed Ur Rehman ◽  
Tao Sun ◽  
Hasan Shahzad ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Rotational Velocity ◽  
Geometric Theory ◽  
Mechanical Efficiency ◽  
Operating Conditions ◽  
Experimental Results ◽  
Field Analysis ◽  
Total Efficiency ◽  
Three Dimensional Model ◽  
Vane Pump

This study presents a novel cylindrical vane pump based on the traditional working principle. The efficiency of the cylindrical vane pump was verified by experimental validation and numerical analysis. Numerical analysis, such as kinematics analysis, was performed in Pro/Mechanism and unsteady flow-field analysis was performed using ANSYS FLUENT. The stator surface equations were derived using the geometric theory of the applied spatial triangulation function. A three-dimensional model of the cylindrical vane pump was established with the help of MATLAB and Pro/E. The kinematic analysis helped in developing kinematic equations for cylindrical vane pumps and proved the effectiveness of the structural design. The maximum inaccuracy error of the computational fluid dynamics (CFD) model was 5.7% compared with the experimental results, and the CFD results show that the structure of the pump was reasonable. An experimental test bench was developed, and the results were in excellent agreement with the numerical results of CFD. The experimental results show that the cylindrical vane pump satisfied the three-element design of a positive-displacement pump and the trend of changes in efficiency was the same for all types of efficiency under different operating conditions. Furthermore, the volumetric efficiency presented a nonlinear positive correlation with increased rotational velocity, the mechanical efficiency showed a nonlinear negative correlation, and the total efficiency first increased and then decreased. When the rotational velocity was 1.33[Formula: see text] and the discharge pressure was 0.68[Formula: see text], the total efficiency reached its maximum value.

scholarly journals Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Giselle Nevares ◽  
Felipe Xavier ◽  
Luciana Gominho ◽  
Flávia Cavalcanti ◽  
Marcely Cassimiro ◽  
...  
Keyword(s):  
Cross Section ◽  
Sodium Hypochlorite ◽  
Reciprocating Motion ◽  
Continuous Motion ◽  
Analytical Balance ◽  
Root Canals ◽  
Apical Extrusion ◽  
Final Weight ◽  
The Difference

This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n=20): the Reciproc (REC), WaveOne (WO), and HyFlex CM (HYF) groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer’s instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α=5%). All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p<0.05), and both systems produced a greater apical extrusion of debris than HyFlex CM (p<0.001). Cross section and motion influenced the results, despite tip standardization.

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