Implications of cavitation in individual grooves of spiral groove bearings

Document type: Journal Articles
Article type: Original article
Peer reviewed: Yes
Author(s): Göran Broman
Title: Implications of cavitation in individual grooves of spiral groove bearings
Journal: PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
Year: 2001
Volume: 215
Issue: J5
Pagination: 417-424
ISSN: 1350-6501
Publisher: PROFESSIONAL ENGINEERING PUBLISHING LTD
City: BURY ST EDMUNDS
ISI number: 000172708300002
Organization: Blekinge Institute of Technology
Department: Dept. of Mechanical Engineering (Institutionen för maskinteknik)
Dept. of Mechanical Engineering S-371 79 Karlskrona
+46 455 38 50 00
http://www.ima.bth.se/
Language: English
Abstract: The pressure distribution in a flat spiral groove thrust bearing obtained from a straightforward solution of the Reynolds equation includes subatmospheric pressure in part of the grooved area, This is masked in the common theory based on the assumption of an infinite number of grooves. Furthermore, the negative contribution to the load capacity from this area is usually small, which may explain why the presence of subatmospheric pressure has not been given much attention in connection with these bearings. Subatmospheric pressure is, however, necessary for liquid-lubricated flat spiral groove thrust bearings of conventional design to work at all at low numbers of grooves, which in turn requires a non-zero cavitation pressure. Cavitation within individual grooves implies non-linearity in, for example, the relation between load capacity and rotational speed of the bearing and limits the obtainable load capacity. This is more pronounced and important to consider at low numbers of grooves (wide grooves) than at high numbers of grooves (narrow grooves), and it is difficult to determine for what number of grooves that reliable prediction of bearing performance can be expected. It depends on the actual value of the cavitation pressure and other parameters that are usually unknown or difficult to account for. To avoid this disadvantage a modified design of liquid-lubricated flat spiral groove thrust bearings is suggested.
Subject: Mechanical Engineering\General
Keywords: spiral groove bearings, low groove numbers, cavitation, load limitation, modified design, supply areas
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