Abstract
One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. A very important condition for describing the frictional behavior of a piston ring correctly is knowledge
about the amount of lubricant present.
For piston rings the external load may be established by measuring the pressure distribution, i.e. the pressure drop in the piston ring package. Speed and temperature may also be established. The amount and distribution of oil present is, however, not easily determined. It is often assumed that it operates under fully flooded conditions,
but this is not the case in real life operation. These problems forms the basis for the experimental investigation.
In large two-stroke engines the cylinder oil is supplied to the bearing at discrete locations on the cylinder liner at a specific rate at a certain time. The shifting in lubrication regimes and the non-uniform oil distribution opens for the possibility of starved conditions for the piston ring bearing. Therefore it is important to measure the oil distribution on the liner as a function of the
operating conditions. The amount of lubricant available is reflected in the friction absorbed in the bearing.
The following properties are measured: Oil film thickness - along liner (axial variation), oil film thickness - along piston ring (circumferential variation), piston tilt, temperature of piston rings and liner, pressure at piston lands and forces on piston rod.
Since the frictional forces are small compared to the rest of the acting forces the main design idea is to fix the piston, while the cylinder liner moves. This approach makes it simple to measure the parameters mentioned above by putting the instrumentation in the piston.
The aim of this paper is describe the tribological condition between a piston ring and cylinder. A test apparatus is used to study the interaction between a piston ring and a cylinder liner.
The piston ring experiences hydrodynamic, mixed and boundary lubrication and the squeeze effect of the piston ring is significant. Experimental results are presented and the influence from speed, number of piston rings, lubrication oil type and supply flow is discussed.
Original language | English |
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Title of host publication | International Tribology Conference : BaltTrib'2007 |
Number of pages | 267 |
Volume | 1 |
Place of Publication | Kaunas, Lithuania |
Publisher | Lithuanian University of Agriculture |
Publication date | 2007 |
Pages | 16-21 |
Publication status | Published - 2007 |
Event | BALTTRIB' 2007: International Tribology Conference - Lithuanian University of Agriculture, Kaunas, Lithuania Duration: 21 Nov 2007 → 23 Nov 2007 |
Conference
Conference | BALTTRIB' 2007: International Tribology Conference |
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Location | Lithuanian University of Agriculture |
Country/Territory | Lithuania |
City | Kaunas |
Period | 21/11/2007 → 23/11/2007 |
Keywords
- Experimental results
- Piston Rings
- Lubrication Regimes