Predicting the Required Slipper Hold-Down Force Within an Axial-Piston Swash-Plate Type Hydrostatic Pump

2001 ◽  
Author(s):  
Noah D. Manring
Keyword(s):  
Theoretical Calculations ◽  
A Priori ◽  
Operating Conditions ◽  
Design Parameters ◽  
A Posteriori ◽  
Axial Piston Pump ◽  
Pump Design ◽  
Swash Plate ◽  
Axial Piston ◽  
Plate Type

Abstract The objectives of this research are to determine the physical contributors that tend to separate the slippers from the swash plate within an axial-piston pump. Upon determining these contributors, the hold-down force that is required for maintaining contact between the slippers and the swash plate is determined. This force is then expressed in terms of pump design-parameters and operating conditions. Physically inspecting six industrial pumps and measuring the theoretical calculations against the a-posteriori results of successful pump designs validates the analytical results of this research. By confirming the analysis of this research, an a-priori approach is recommended for adequately specifying the required spring load for the slipper hold-down mechanism.

New Swash Plate Damping Model for Hydraulic Axial-Piston Pump

1999 ◽  
Vol 123 (3) ◽  
pp. 463-470 ◽  
Author(s):  
X. Zhang ◽  
J. Cho ◽  
S. S. Nair ◽  
N. D. Manring
Keyword(s):  
Open Loop ◽  
Operating Conditions ◽  
Reduced Order Model ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Order Model ◽  
Nonlinear Simulation ◽  
Reduced Order ◽  
Swash Plate ◽  
Axial Piston

A new, open-loop, reduced order model is proposed for the swash plate dynamics of an axial piston pump. The difference from previous reduced order models is the modeling of a damping mechanism not reported previously in the literature. An analytical expression for the damping mechanism is derived. The proposed reduced order model is validated by comparing with a complete nonlinear simulation of the pump dynamics over the entire range of operating conditions.

Design and Analysis of a Swashplate Control System for an Asymmetric Axial Piston Pump

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Wei He ◽  
Jia-Hai Huang ◽  
Hui-Min Hao ◽  
Long Quan ◽  
Shuai-xu Ji ◽  
...  
Keyword(s):  
Control System ◽  
Open Loop ◽  
System Dynamic ◽  
Piston Pump ◽  
Design Parameters ◽  
Axial Piston Pump ◽  
Swash Plate ◽  
Design Requirements ◽  
Bode Diagram ◽  
Axial Piston

Abstract Based on the previously developed fixed-displacement asymmetric axial piston pump, a variable displacement asymmetric axial piston pump (VDAAPP) with three independent suction/delivery ports is proposed. A basic linear model of VDAAPP is established to get open-loop bode diagram. Based on open-loop Bode diagram features and design requirements, P-controller is determined for VDAAPP. Then VDAAPP's performance is investigated by advanced modeling environment for performing simulations of engineering systems (AMESim) and automatic dynamic analysis of mechanical systems (ADAMS) joint simulation, and some key design parameters are obtained. Next, a VDAAPP prototype with a maximum displacement of 40 cc/rev is designed and manufactured, ratio of flow rates at ports A, B and T is 1:0.6:0.4. Due to hard limitations of the test bench, the performance only under the conditions of the opposite passive loads is tested. Preliminary test results indicate that VDAAPP prototype works normally and meets the design requirements for flow ratio, and the maximum rise time of the test pressure is about 0.32 s. However, due to special design of VDAAPP valve plate, the swash plate torque severely limits system dynamic response. Therefore, an improved swashplate control system based on asymmetric-valve-controlled asymmetric-piston scheme is presented as well, it is found to be an effective way to suppress the negative impact of swash plate torque on system dynamic performance. This provides a direction for the optimization of the swashplate control system for asymmetric axial piston pumps in the future.

Lubrication characteristics of the slipper–swash-plate interface in a swash-plate-type axial piston pump

2020 ◽  
pp. 095440622093294
Author(s):  
Xiangxu Meng ◽  
Chang Ge ◽  
Hongxi Liang ◽  
Xiqun Lu ◽  
Xuan Ma
Keyword(s):  
Hydrodynamic Lubrication ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Plate Interface ◽  
Load Pressure ◽  
Swash Plate ◽  
Lubrication Performance ◽  
Lubrication Characteristics ◽  
Axial Piston ◽  
Plate Type

An analytical approach based on a hydrodynamic lubrication model is presented to understand the bearing capacity, leakage, and friction moment of the slipper–swash-plate interface in a swash-plate-type axial piston pump. Furthermore, how the shaft speed, load pressure, and slipper attitude influence the lubrication performance of the interface is analyzed. The research shows that the slipper attitude has a significant effect on the pressure distribution. To improve the lubrication performance, a grooved sealing-land design is proposed, and the location and geometric parameters of the groove are analyzed. The results indicate that the optimal lubrication performance is achieved when the groove is 2.0–3.0 mm wide and 5–20 µm deep at its inner boundary.

Designing the Shaft Diameter for Acceptable Levels of Stress Within an Axial-Piston Swash-Plate Type Hydrostatic Pump

1999 ◽  
Vol 122 (4) ◽  
pp. 553-559 ◽  
Author(s):  
Noah D. Manring
Keyword(s):  
Hydraulic System ◽  
Point Of View ◽  
Stress Concentrations ◽  
Working Pressure ◽  
Pump Design ◽  
Shaft Diameter ◽  
Swash Plate ◽  
Stress Point ◽  
Axial Piston ◽  
Plate Type

In this research, the diameter of the shaft within an axial-piston swash-plate type hydrostatic pump is considered from a stress point of view. To analyze the loading of the shaft, the components within the pump are studied using a force and torque diagram and it is shown that the loads are applied differently for three main sections of the shaft. From the force and torque diagram, the actual shaft loads are determined based upon the geometry of the pump and the working pressure of the hydraulic system. Using well-accepted machine design practices, governing equations for the shaft diameter are produced for the various regions of loading along the shaft. These equations consider both bending and torsional stresses on the outer surface of the shaft. Results for the required shaft diameter are then computed for a typical pump design and compared to the geometry of an actual shaft. It is noted that stress concentrations can significantly alter these results and that the required shaft diameter can be reduced by applying the proper heat treatments and increasing the shaft strength. Finally, the designer is cautioned regarding the deflection difficulties that can arise when the shaft diameter is reduced too much. [S1050-0472(00)01704-9]

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