Journal ArticleDOI
Tribological Interaction between Piston and Cylinder of a Model High Pressure Hydraulic Pump
J. R. Dowd,F. T. Barwell +1 more
TLDR
In this paper, a cam-operated single cylinder pump was used to test several pump material combinations using two chemically different hydraulic fluids and the main parameters monitored were the degree of mutual electrical insulation attained and the physical drag of the piston on the cylinder due to both viscous shear and asperity interaction.Abstract:
Conventional high-pressure hydraulic piston pumps require a delicate balance between clearance, surface finish, and pump materials if a long, efficient life is to be maintained. A cam-operated single cylinder pump has been used to test several pump material combinations using two chemically different hydraulic fluids. The main parameters monitored were the degree of mutual electrical insulation attained and the physical drag of the piston on the cylinder due to both viscous shear and asperity interaction. It was found that for hardened steel pistons and cylinders an optimum surface finish of approximately 8 μinches CLA gave the best results with both fluids. Results are explained on the basis of micro-asperity hydrodynamic lift. Presented at the 29th Annual Meeting in Cleveland, Ohio, April 28–May 2, 1974read more
Citations
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Journal ArticleDOI
Heat Transfer and Thermal Elastic Deformation Analysis on the Piston/Cylinder Interface of Axial Piston Machines
TL;DR: In this paper, a fully coupled simulation model was developed to analyze the piston/cylinder interface behavior, considering the fluid-structure interaction and thermal problems, and the simulation results for an existing hydrostatic unit were discussed.
Journal ArticleDOI
Mixed Lubrication Characteristics Between the Piston and Cylinder in Hydraulic Piston Pump-Motor
Yi Fang,Masataka Shirakashi +1 more
TL;DR: In this article, a numerical analysis is carried out to obtain the metal contact force between the piston and cylinder, and the contact ratio λ is shown to represent the mixed lubrication condition both for the pump and the motor strokes.
Journal ArticleDOI
Tribology, lubricants and lubrication engineering — a review
TL;DR: More than 200 papers published between 1974 and 1976 are evaluated as discussed by the authors, which deal with the fundamentals of friction, wear and lubrication, including the state of friction and materials, and analytical data and properties of mineral oil and synthetic lubricants, lubricating greases, additives and solid lubricants.
Journal ArticleDOI
A new approach to the design of sealing and bearing gaps of displacement machines
TL;DR: In this article, a non-isothermal gap flow simulation method for self-adjusting gaps is proposed, and two basic test rigs for the measurement of friction and temperature behavior in the gap between piston and cylinder of an axial piston machine under real operating conditions.
Journal ArticleDOI
Investigation of the gap flow in displacement machines considering elastohydrodynamic effect
TL;DR: In this article, the authors introduced a new method for complex gap flow simulation of connected and self-adjusting gaps of axial piston machines, where the model for the piston/cylinder pair was extended to consider elastohydrodynamic effects.
References
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Journal ArticleDOI
Contact of Nominally Flat Surfaces
TL;DR: In this article, the authors proposed a new theory of elastic contact, which is more closely related to real surfaces than earlier theories, and showed how the contact deformation depends on the topography of the surface, and established the criterion for distinguishing surfaces which touch elastically from those which touch plastically.
Journal ArticleDOI
A simple theory of asperity contact in elastohydro-dynamic lubrication
TL;DR: In this article, the Greenwood and Williamson theory of random rough surfaces in contact has been combined with established elastohydrodynamic theory to provide a theoretical approach to highly loaded lubricated contacts in which the load is shared between hydrodynamic pressure and asperity contact.
Journal ArticleDOI
Metallic Contact and Friction between Sliding Surfaces
TL;DR: In this article, the authors measured both the instantaneous and average electrical resistance between the two surfaces and found that the electrical resistance oscillates rapidly between an extremely low value and infinity, suggesting that metallic contact is discontinuous.
Journal ArticleDOI
The Contact Resistance and Mechanical Properties of Surface Films on Metals
TL;DR: In this paper, it was shown that the change from oxide-onoxide to metal-on-metal sliding was usually accompanied by changes in the coefficient of friction, the nature of the sliding, and the appearance of the track.
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Mixed Lubrication Characteristics Between the Piston and Cylinder in Hydraulic Piston Pump-Motor
Yi Fang,Masataka Shirakashi +1 more