| 摘要 |
<p>A spring expander (10) for oil control piston ring incorporates two spring mechanisms. One spring mechanism (11, 12a, 12b,) produces circumferentially directed hoop stress in the expander body when the expander body itself is contracted. A second radially acting spring mechanism (31a, 31b) is provided by circumferentially spaced spring fingers (31a, 31b) which radially deflect. Because the two spring mechanisms act together, the expander has a combined spring rate which is lower than the spring rate of either the circumferential spring mechanism or the spring rate of the radial spring mechanism. The expander also has expansion stops (39) which limit the radial expansion of the spring fingers, and thereby limit the expansion of the associated rail ring to reduce pop-out during assembly. Contraction stops (17, 18) limit radial contraction of the rail ring with respect to the expander and maintain a clearance between the expander and the cylinder wall.</p> |
