 |
 |
 |
| Engine lubricating oil performs an essential protective function in the engine by allowing parts to slide and by preventing them from making direct metal-to-metal contact (reducing friction), which causes wear, and in the worst case, total engine failure. Engine oil reduces operating friction, making the engine more efficient; while also serving to cool critical engine components and trapping harmful dirt particles. |
 |
|
|
Can you see how it is assembled? This 3-piece oil ring is installed into the piston groove and functions as an assembly to generate the required performance. The oil ring assembly above has a diameter of 86mm, an axial width of 2.0mm and a radial thickness of 2.5mm. |
 |
| The thin, upper and lower plate-shaped rings are referred to as side rails. Each side rail is about 0.4mm wide. Each oil ring assembly requires two side rails: an upper side rail and a lower rail. The periphery of each side rail makes contact with the cylinder walls and slides. A hard film of CrN (nitrided chromium) has been applied to the running face by a PVD process. Other surface treatments for the side rails' running face include nitriding and hard chrome plating. |
 |
| The wave design seen in the picture below allows the spacer
expander to act as a spring. The spring action of the spacer expander presses
the side rails against the cylinder wall until the correct tension and unit wall
pressure are achieved. |
|
|
| As mentioned above, the two side rails and the spacer expander form
an oil ring set or assembly. This is why it is referred to as a three-piece ring. |
 |
|
|
| The oil ring illustrated above is a two-piece assembly
that is used most often for diesel engines and some of gasoline engines applications.
We refer to this ring as a oil ring assembly. This oil ring assembly consists
of a M-shaped steel rail and a cylindrical coil spring. The DVM is characterized
by its lightweight, high conformability and its ability to accurately control
oil and reduce oil consumption. |
Japanese 
