RESEARCH ON AX-LEAK PROPERTY OF POLYMER FLUID IN HELICAL GEAR PUMP

The concept of continuous-contact helical gear pumps (CCHGP) has been proposed and successfully commercialized in the recent past. Thanks to the continuous-contact rotor profile design and to the helical gear structure, this design eliminates the kinematic flow oscillation. This has important implications on the fluid borne noise generation, which is considered as one of the major sources of noise emissions and mechanical vibrations for positive displacement machines. Although the commercial success of the CCHGP concept, there is very little published studies about the underling physics at the basis of the functioning of this type of design. This is mostly due to the complexity of the fluid domain that characterize the functioning of CCHGP units. In this paper, a transient 3D CFD study is conducted for a reference CCHGP unit for high-pressure (up to 200 bar) fluid power applications. The results of the 3D CFD simulation are compared with those given by a lumped-parameter model developed at the Maha Fluid Power Research Center of Purdue University (USA), which was previously validated against experimental results. The results show how with a proper discretization of the fluid domain the CFD simulation approach can be used for the case of helical CCHGP units. Both models provide a good description of the main features of operation of the unit. The lumped parameter model is quicker, thus suitable for fast optimization studies. However, the CFD results not only can be used to support the main assumptions done on the lumped parameter model, they also permit to gain further insight on the operation of the CCHGP unit, particularly with respect to the flow features of the meshing process.

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A New Continuous Contact Low-Noise Gear Pump

Journal of Mechanisms Transmissions and Automation in Design ◽

10.1115/1.3258544 ◽

1983 ◽

Vol 105 (4) ◽

pp. 736-741 ◽

Cited By ~ 10

Author(s):

K. Mitome ◽

K. Seki

Keyword(s):

Point Contact ◽

Practical Method ◽

Spur Gear ◽

Helical Gear ◽

Low Noise ◽

Tooth Profile ◽

Gear Pump ◽

Excellent Performance ◽

Continuous Contact ◽

Gear Pumps

Developed is a new low-noise gear pump which has no trapping and whose gears are in continuous one-point contact in the plane of rotation. First this paper studies a practical method to design the tooth profile of a spur gear for a given path of contact. A new tooth profile is obtained by giving a closed path of contact like a figure 8. Basic dimensions are determined and limites of them are obtained. Both theoretical and approximate displacements are expressed in terms of the basic dimensions. Secondly, a helical gear pump is studied. The helical gear can be discussed in the same way as the spur gear by new basic dimensions. Finally some test gear pumps are made and tested. Test prove that this gear pump has excellent performance and durability.

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The Equation of the Contact Line of the Involute Curvilinear-Tooth Cylindrical Gear Pump for the Agricultural Tractor

The Open Mechanical Engineering Journal ◽

10.2174/1874155x01408010879 ◽

2014 ◽

Vol 8 (1) ◽

pp. 879-884 ◽

Cited By ~ 2

Author(s):

Yi-Qiang Jiang ◽

Li Hou ◽

Yong Zhao

Keyword(s):

Contact Line ◽

Helical Gear ◽

Tooth Surface ◽

Gear Pump ◽

Mathematical Software ◽

Coordinate Systems ◽

Cylindrical Gear ◽

Face Width ◽

Meshing Equation ◽

Agricultural Tractor

In order to derive the equation of the contact line of the involute curvilinear-tooth cylindrical gear pump for the agricultural tractor, the tooth surface of the involute curvilinear-tooth cylindrical gear is firstly generated as that of the spur or helical gear. Then the equation of the tooth surface is derived from changing the settings and orientations of the coordinate systems after the equation of the tooth profile in an arbitrary radial section is calculated by the methods of differential geometry. Based on the equation of the tooth surface, the meshing equation of the two gears is further acquired and then the equation of the contact line. Finally, the tooth surface and the contact line are simulated with mathematical software. The results suggests that the contact line between two curvilinear-tooth cylindrical gears is an arc line in the surface of action; and this line, shaped as an arc line in the generating plane of the tooth surface, is longer than that of the spur or helical gear with the same face width.

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