Segmented Piston Ring Joint for Thermal Expansion Sealing
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Solution Overview
Problem
Existing piston rings suffer from incomplete sealing due to the annular gap, leading to pressure loss and medium overflow, especially under conditions of thermal expansion and wear.
Innovation Solution
A sealing piston ring design featuring a rotationally symmetrical structure with an inclined ring surface and a parting plane, which promotes dynamic expansion and self-centering, ensuring a precise sealing geometry and automatic adjustment for wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an annular gap is provided in the piston ring to allow for thermal expansion, then the piston ring can accommodate thermal effects, but sealing effectiveness deteriorates due to incomplete gap closure and increased leakage
Solution Approach 1:
The piston ring is divided into two separate ring body ends (first and second ring body ends) that can move independently relative to each other along the circumferential direction. This segmentation allows each end to respond to thermal expansion independently while maintaining sealing contact through the parting plane, resolving the contradiction between thermal adaptability and sealing effectiveness.
Solution Approach 2:
The piston ring transitions from a static rigid structure to a dynamic structure where the two ring body ends can slide relative to each other along the parting plane. This dynamic capability enables the ring to adapt to thermal expansion while maintaining continuous sealing contact, as the ends can adjust their positions to close the gap completely even when expanded.
2Ease of manufacture
If the piston ring is designed with a simple circular cross-section, then manufacturing is easier, but sealing performance deteriorates under varying pressure and thermal conditions
Solution Approach 1:
The piston ring incorporates a parting plane with specific geometric features (separating surfaces with complementary shapes) localized at the ring joint area. This local structural differentiation provides enhanced sealing capability at the critical joint region while maintaining simpler manufacturing elsewhere, resolving the contradiction between manufacturing ease and sealing performance.
3Device complexity
If the piston ring uses a fixed preload force, then the structure is simpler, but sealing effectiveness deteriorates as medium pressure dynamics cannot be compensated
Solution Approach 1:
The piston ring design allows the two ring body ends to self-adjust their relative positions along the parting plane in response to varying medium pressure and thermal conditions. The complementary separating surfaces automatically maintain sealing contact without requiring external adjustment mechanisms, providing adaptive sealing performance while maintaining structural simplicity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves almost complete tightness against fluid and gaseous pressure media, maintaining sealing effectiveness even with variable circumferential expansion and wear, while reducing wear and ensuring consistent sealing performance.
Implementation Method 1
the wedge effect on the inclined ring surface leads to a radial expansion of the piston ring and to a force acting on the surface pressure between the radial ring surface and the inner surface of the cylinder
Implementation Method 2
when the piston moves back without working pressure, the surface pressure is reduced to the surface pressure due to the spring effect, thus reducing wear
Implementation Method 3
the contact being a sliding contact when the piston moves relative to the cylinder
Data Source
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AI summary
The invention relates to a piston ring, comprising a ring body (1) and a ring joint (9), wherein the ring body (1) comprises, lying opposite one another, a first (7) and second ring body end (8) which form the ring joint (9), wherein the first ring body end (7) comprises a projection portion (10) with a projection contour cross section (11), wherein the second ring body end (8) comprises a base portion (12) with a base portion contour (13), wherein a projection portion parting surface (16) of the projection portion (10) and a base portion parting surface (17) of the base portion (12) lie opposite one another in areal and sealing physical contact and form a parting plane (18), wherein the parting plane (18) has an inverse slope with respect to a sloped ring surface (5), wherein the parting plane (18) forms an outer parting line (19) and an inner parting line (20), and wherein at least one of the parting lines (19, 20) has a curvature radius which is concentric with respect to the ring body (1).