Study on the Angle of Stationary Crescent for Radial Compensation of Inner Mesh Gear Pumps

2011 ◽  
Vol 317-319 ◽  
pp. 1438-1443
Author(s):  
Jian Zhuo Zhang ◽  
Kang Kang Li ◽  
Meng Gao ◽  
Tian Zi Zhu
Keyword(s):  
High Pressure ◽  
Pressure Distribution ◽  
Volumetric Efficiency ◽  
Hydraulic Pressure ◽  
Working Mechanism ◽  
Outlet Pressure ◽  
Hydraulic Force ◽  
Pressure Area ◽  
Gear Pumps ◽  
Internal Gear

Abstract：The working mechanism of the stationary crescent for radial compensation in the inner mesh gear pumps was studied in this paper. The force of the top and bottom stationary crescent in one hydraulic pressure changing cycle was analysed. The pressure distribution on the top and bottom stationary cressent in different positions and the hydraulic force at the x，y direction were determined.Under the condition of the force of the top and bottom stationary crescent is least and the two stationary crescents stay close to the tooth crest of internal gear and external gear to form radial seal，the angle of the end of the top stationary crescent in the high pressure area and the fixing angle of the seal stick was optimized. Experiment results show that the volumetric efficiency is 0.94 when the outlet pressure reach to 30Mpa, and the oil temperature is less than 55°C, there is no abrasion on the two sationary crescents and the tooth crest.

Study on Tooth Profile of Involute Conjugated Internal Gear for High-Pressure Internal Gear Pumps

2011 ◽  
Vol 328-330 ◽  
pp. 186-189 ◽  
Author(s):  
Wei Song ◽  
Hua Zhou
Keyword(s):  
High Pressure ◽  
3D Models ◽  
Tooth Profile ◽  
Volumetric Efficiency ◽  
Flow Pulse ◽  
Wear Life ◽  
Gear Pumps ◽  
Gear Geometry ◽  
Internal Gear

Conjugated internal gear is the key component of high-pressure internal gear pumps, which decides the performance of the pumps, such like volumetric efficiency, capacity of fluid discharge, wear life, flow pulse, vibration and noise. In this paper, a method of generating tooth profiles for conjugated internal gear is presented. Based on gear geometry and meshing theory, the parametric equations of involute conjugated internal gear are derived. With the help of MATLAB and SolidWorks, 3D models of the gear couple are built to evaluate the feasibility of the method.

Calculation Method of Lubricant Film Pressure Distribution of Axial Piston Pump Slippers

2013 ◽  
Vol 328 ◽  
pp. 629-633
Author(s):  
Ya Jun Wang
Keyword(s):  
High Pressure ◽  
Pressure Distribution ◽  
Mass Conservation ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Shearing Flow ◽  
Pump Speed ◽  
Pressure Area ◽  
The Difference ◽  
Axial Piston

A method is implemented to get the pressure distribution of the axial piston pump slipper. Slipper was seen as translating thrust bearing, taking slipper tilt and spin in account, based on finite volume method, hydrodynamic and hydrostatic pressure has been calculated by using the mass conservation principle. For a representative element volume, the difference flow was averaged by the difference flow between the tilting planes, and the shearing flow by slipper translating was averaged by the shearing flow between the tilting planes. The numerical calculating result based two liquid resistance assume was compared, the results showed that two methods have got the same pressure distribution schematics, and the high pressure area locates at the slipper titling direction, but for the pressure values at high pressure area, the second method is slightly higher than the first method, and that the higher pump speed were, the higher the pressure values, and at the same pump speed, the slipper spin speed affects slightly the pressure, and at the lower pump speed, the lubricant pressure tends to the hydrostatic lubrication.

High-Pressure Gear Pumps

1946 ◽  
Vol 155 (1) ◽  
pp. 417-452 ◽  
Author(s):  
T. E. Beacham
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Journal Bearings ◽  
Volumetric Efficiency ◽  
Solid Matter ◽  
Excessive Pressure ◽  
Low Viscosity ◽  
Large Numbers ◽  
Gear Pumps ◽  
The Relationship

Gear pumps have been used in very large numbers for the various hydraulic services of war aircraft. For the higher pressures the main problems have been in connexion with the load on the journal bearings, with wear, and with the reduction in volumetric efficiency caused by internal leakage. The journal loads are affected by the number of teeth and by the ratio of width to diameter of the gears. With high pressures it is difficult to accommodate standard ball or roller races on account of their diameter: designs are illustrated using a combination of standard races and special needle roller bearings. Small amounts of wear cause comparatively large reductions in volumetric efficiency. Major causes of wear are rubbing on the gear end faces and solid matter in suspension in the liquid and methods of dealing with these are discussed. The percentage slip due to internal leakage varies inversely as the factor (r.p.m. × viscosity). At low speeds and with low-viscosity liquids, internal leakage often limits the pressure at which the pump can be used. Multistage pumps reduce the leakage and have been used extensively for undercarriage operation. Internal leakage becomes relatively less as the size of the pump is increased and the paper gives a graph, showing the relationship between the limit of pressure at which 80 per cent volumetric efficiency is possible, the capacity and rotational speed of the pump, and the viscosity of the liquid. Aircraft pumps generally use gears with involute teeth: ports in the end covers of the casing are used to prevent excessive pressure in the liquid trapped between the teeth. Low- and high-leakage conditions call for difficult arrangements of ports, and this involves differing displacements and variations in flow velocity.

Effects of Fillet on Kinematic Characteristic of Internal Gear Couple

2011 ◽  
Vol 130-134 ◽  
pp. 1128-1131
Author(s):  
Wei Song ◽  
Hua Zhou
Keyword(s):  
High Pressure ◽  
Kinematic Analysis ◽  
Gear Transmission ◽  
Kinematic Characteristic ◽  
Gear Pumps ◽  
Simulation Results ◽  
Internal Gear

Internal gear couple is the key component of high-pressure internal gear pumps, kinematic characteristic of which directly influences performance of the pump. Fillet is always ignored in the studies of gear transmission. This paper presents kinematic analysis of internal gear couple by using Adams which takes fillet into account. On the base of simulation results, the effects of fillet on kinematic characteristic of internal gear couple are concluded.

scholarly journals Development tendencies of clearance compensation methods in internal gear pumps

2021 ◽  
Vol 338 ◽  
pp. 01021
Author(s):  
Piotr Osiński ◽  
Michał Stosiak ◽  
Paweł Bury ◽  
Rafał Cieślicki ◽  
Krzysztof Towarnicki ◽  
...  
Keyword(s):  
Experimental Research ◽  
Mechanical Efficiency ◽  
Volumetric Efficiency ◽  
Positive Displacement ◽  
Compensation Methods ◽  
Gear Pumps ◽  
Design Solutions ◽  
Materials Used ◽  
Internal Gear

Contemporary gear pumps, although their design has been under development for over four centuries, keep being modernized and improved. The work presents an analysis of design solutions, taking into account their operational features. The analysis included units with internal mesh. Emphasis was put on the problem of ensuring high values of volumetric efficiency by minimizing leakage in the widest possible range of loads while maintaining the highest possible hydraulic and mechanical efficiency of the displacement unit. Increasing the volumetric efficiency of positive displacement pumps is an important factor in the pursuit of increase in working pressures in hydrostatic systems. An important factor in production of pumps is cost of their production, which often leads to possibility of introducing additional modifications in the pump structure. Often changes made to the materials used in construction of pumps, allow reduction in their mass or sensitivity to the action of the transported liquid. The paper indicates the developed and proprietary solutions in this area and presents the results of experimental research.

scholarly journals Effect of an Improved Yasutomi Pressure-Viscosity Relationship on the Elastohydrodynamic Line Contact Problem

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Vincenzo Petrone ◽  
Adolfo Senatore ◽  
Vincenzo D'Agostino
Keyword(s):  
High Pressure ◽  
Film Thickness ◽  
Free Volume ◽  
Experimental Studies ◽  
Line Contact ◽  
Volume Model ◽  
Free Volume Model ◽  
Pressure Area ◽  
New Formulation ◽  
Lubricant Viscosity

This paper presents the application of an improved Yasutomi correlation for lubricant viscosity at high pressure in a Newtonian elastohydrodynamic line contact simulation. According to recent experimental studies using high pressure viscometers, the Yasutomi pressure-viscosity relationship derived from the free-volume model closely represents the real lubricant piezoviscous behavior for the high pressure typically encountered in elastohydrodynamic applications. However, the original Yasutomi correlation suffers from the appearance of a zero in the function describing the pressure dependence of the relative free volume thermal expansivity. In order to overcome this drawback, a new formulation of the Yasutomi relation was recently developed by Bair et al. This new function removes these concerns and provides improved precision without the need for an equation of state. Numerical simulations have been performed using the improved Yasutomi model to predict the lubricant pressure-viscosity, the pressure distribution, and the film thickness behavior in a Newtonian EHL simulation of a squalane-lubricated line contact. This work also shows that this model yields a higher viscosity at the low-pressure area, which results in a larger central film thickness compared with the previous piezoviscous relations.

Friction of outer rotor affecting friction torque characteristics in an internal gear pump

2014 ◽  
Vol 229 (16) ◽  
pp. 3013-3026 ◽  
Author(s):  
Yoshiharu Inaguma
Keyword(s):  
Pressure Distribution ◽  
Friction Force ◽  
Significant Loss ◽  
Friction Torque ◽  
The Body ◽  
Gear Pump ◽  
Suction Pressure ◽  
Outer Rotor ◽  
Internal Gear ◽  
Outer Circumference

This article presents the friction torque in an internal gear pump and the friction force between an outer circumference of an outer rotor and a body, which causes a significant loss, has been investigated. When in use at a high pressure, the pump has a large friction torque due to the friction force acting on the outer rotor circumference. This friction force is caused by imbalanced force acting on the outer rotor. As well as by a positioning suction and a delivery port, the force can be reduced by setting a suction pressure recess in a section of the outer rotor circumference. In this study, through the measurement of the friction torque in an actual pump and the pressure distribution on the outer circumference of the outer rotor, it is investigated how the suction pressure recess can change the force acting on the outer rotor. The actual internal gear pump without the suction pressure recess has a large friction torque, and it corresponds to a large force on the outer rotor, which is calculated from the pressure distributions on the inside and outside of the outer rotor. In addition, on the basis of the measured friction torque of the test pump and the force acting on the outer rotor, calculated using the results of the pressure distribution, the coefficient of friction between the outer rotor circumference and the body can be estimated.

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