Modeling and Analysis of the Dynamics of a Variable-Displacement Vane-Pump With a Pivoting Cam

1988 ◽  
Vol 110 (2) ◽  
pp. 197-202 ◽  
Author(s):  
A. M. Karmel
Keyword(s):  
Steady State ◽  
Pressure Fluctuations ◽  
Vane Pump ◽  
Modeling And Analysis ◽  
Operating Variables ◽  
Levels Of Detail ◽  
Variable Displacement Vane Pump ◽  
Variable Displacement ◽  
Internal Mechanism ◽  
Different Levels

Variable-displacement vane-pumps, modulated by a pivoting cam, are used extensively in modern automotive transmissions. This paper presents a study of the dynamic and steady-state characteristics of such pumps. Their dynamics concern issues such as pressure fluctuations due to the dynamics of the internal mechanism and transient response-time. Their steady-state characteristics concern limits on the operating envelope and the relationships among the operating variables. These analyses required the development of several models for this type of pump at different levels of detail.

Stability and Regulation of a Variable-Displacement Vane-Pump

1988 ◽  
Vol 110 (2) ◽  
pp. 203-209 ◽  
Author(s):  
A. M. Karmel
Keyword(s):  
Hydraulic System ◽  
Critical Frequency ◽  
Pressure Fluctuations ◽  
Resistive Load ◽  
Pressure Regulation ◽  
Vane Pump ◽  
Variable Displacement Vane Pump ◽  
Variable Displacement ◽  
Line Pressure ◽  
The Stability

Pressure fluctuations may develop in the hydraulic system of automatic transmissions, even under steady-state conditions. To analyze this phenomenon, a dynamic model was developed for a system which consists of a variable-displacement vane-pump, a regulator, and a resistive load. The model was linearized and reduced to generate a stability criterion for the pressure-regulation circuit. This criterion determines a critical frequency that the natural frequency of the pressure-regulation valve must exceed to assure stability. This critical frequency depends primarily on the damping of the spool of the pressure-regulation valve and on its position; the latter is a function of the regulation-chamber leakage characteristics. The analysis shows that line pressure, flow and leakage, along with production tolerances and different opening conditions, have a significant effect on the stability of the hydraulic system. Test data support the analysis.

A Study of the Internal Forces in a Variable-Displacement Vane-Pump—Part II: A Parametric Study

1986 ◽  
Vol 108 (2) ◽  
pp. 233-237 ◽  
Author(s):  
A. M. Karmel
Keyword(s):  
Parametric Study ◽  
Analytical Study ◽  
Design Criterion ◽  
Vane Pump ◽  
Continuous Components ◽  
Variable Capacity ◽  
Variable Displacement Vane Pump ◽  
Variable Displacement ◽  
Internal Forces ◽  
Line Pressure

This is the second part of an analytical study of the internal forces in a variable-displacement vane-pump. It presents a parametric study of the forces and torques applied to the mechanism and the shaft of this pump, as functions of line pressure, the eccentricity, and the design geometry. It is shown that the continuous components of the torque and of the direction of the radial shaft-load vary as a sawtooth wave at twice the vane-frequency while the magnitude of the radial shaft-load varies as a square wave at vane-frequency. The design criterion developed in the first part of this study is used to demonstrate the elimination of the magnitude variations in the radial shaft-load. The intermittent components of the internal forces vary as a pulse train at vane frequency and may produce high-peak pressure pulses which must be closely controlled. The variable-capacity feature of variable-displacement vane-pumps has a significant effect on the torque applied to the mechanism, but only a secondary effect on the overall radial shaft-load.

scholarly journals Nonlinear Volume Flow Control of a Variable Displacement Vane Pump

PAMM ◽  
2015 ◽  
Vol 15 (1) ◽  
pp. 635-636 ◽  
Author(s):  
Marius Köster ◽  
Alexander Fidlin
Keyword(s):  
Flow Control ◽  
Volume Flow ◽  
Vane Pump ◽  
Variable Displacement Vane Pump ◽  
Variable Displacement

Lumped Parameter and Three-Dimensional CFD Simulation of a Variable Displacement Vane Pump for Engine Lubrication

2017 ◽  
Author(s):  
Massimo Rundo ◽  
Giorgio Altare
Keyword(s):  
Cfd Simulation ◽  
Dynamic Equilibrium ◽  
Experimental Tests ◽  
Flow Speed ◽  
Displacement Control ◽  
Vane Pump ◽  
Element Analysis ◽  
Transient Model ◽  
Variable Displacement Vane Pump ◽  
Variable Displacement

The paper describes the modelling and the experimental tests of a variable displacement vane pump for engine lubrication. The approach used for the simulation has involved 3D commercial tools for tuning a 0D customized model implemented in the LMS Amesim® environment. Different leakage paths are considered and the axial clearances are variable to take into account the deformation of the pump cover, calculated through a finite element analysis with ANSYS®. The vane tip clearances are calculated as function of the dynamic equilibrium equation of the vanes. The displacement control takes into account the internal forces on the stator due to the pressure in all variable chambers and to the contact force exerted by the vanes. The discharge coefficients in the resistive components have been tuned by means of a complete 3D transient model of the pump built with PumpLinx®. The tuned 0D model has been proved to be reliable for the determination of the steady-state flow-speed and flow-pressure curves, with a correct estimation of the internal leakages and of the pressure imposed by the displacement control. The pump has been also tested using a simplified circuit and a fair agreement has been found in the evaluation of the delivery pressure ripple.

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