Synthetic Approach to the Design, Manufacturing and Examination of Gerotor and Orbital Hydraulic Machines

Abstract

Gerotor technology is an important research area in the field of hydraulics which attracts the attention of both academic scientists and industry. Despite the numerous publications announced by academics, as well as a considerable number of projects made by industry, the subject has not been exhausted. This paper presents a new approach to gerotor technology which has been formed by gathering the authors’ knowledge of gerotors in a synthetic form. The following scientific and technical results have been obtained: (1) A uniform system of parameters and basic concepts regarding toothing and cycloidal gearing (z, m, λ, v, g) which is consistently used to describe the geometry, kinematics, hydraulics and manufacture of those elements; (2) description of the geometry and kinematics of the epicycloidal and hypocycloidal gears with the use of the adopted system of parameters. Additionally, the epicycloidal/hypocycloidal double gearing is presented, which is an original idea of the authors; (3) description of the hydraulics of the gerotor and orbital machines, and in particular: (i) determination of equations for delivery (capacity) q and irregularity of delivery (capacity) δ using the above-mentioned system of basic parameters; (ii) formulation of the principles of designing internal channels and clearances in the gerotor machines and presentation of the original disc distributor in the epicycloidal/hypocycloidal orbital motor; (iii) presentation of the methods of manufacturing the epicycloidal and hypocycloidal gearings with 12 examples of the systems implemented in practice; (4) presentation of the research methods applied for the examination of the gerotor machines, combining computer simulation and experimental research into a coherent and cohesive whole which results in the effect of research synergy. Such a synthesis of knowledge may serve the improvement, creation and investigation of gerotor and orbital machines carried out by academics and industry.

Research into ultrasoic and hydrodinamic cavitation phenomena in a hydraulic system

“…It was confirmed that the oscillator-cavitation system, designed and manufactured on the basis of [20,22], is useful for inducing the phenomenon of ultrasonic cavitation. It was also confirmed that the PIV visualization method based on a special system of illuminating transparent objects and recording the flow through those objects by means of a fast camera are useful in the research on the cavitation phenomena [24,26].…”

“…Thus, it can be concluded that the use of the ultrasonic cavitation and the oil degasification leads to the reduction of the hydrodynamic cavitation. Further limitation of the phenomena of the hydrodynamic cavitation in a gear pump is achieved by design methods, through the application of relief grooves [14,26].…”

“…The objectives of the work have been achieved. Based on [1,2,14,24,26], the course of the ultrasonic cavitation phenomena occurring in a hydraulic tank and the hydrodynamic cavitation in a gear pump have been described. The course of the phenomena was confirmed during experiments carried out with the use of a specially designed tank and pump.…”

“…The course of the hydrodynamic cavitation phenomenon is presented on the basis of [15,25,26] in Fig. 1, on the right.…”

Inter-chamber leakage flow through the transition contacts in epitrochoid generated star and ring hydrostatic units

“…The analysis is performed on both epitrochoidal and hypotrochoidal profiles by taking two non-dimensional parameters related to a geometric approach that supported the law of gearing and developed synthetic equations. Jaros1aw and Piotr 4 has also proposed a synthetic approach to design, manufacturing and also examination of gerotor and orbital hydraulic machines. Sasaki et al 5 had established a new tooth shape named 'Megafloid' by reducing the thickness of the gear and making it smaller in the outer diameter by which the pumping loss gets reduced and gets more discharge volume theoretically.…”