Piston Ring Internal Groove Sealing to Prevent Blow-By
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Solution Overview
Problem
Existing piston rings in internal combustion engines face challenges in preventing oil carbon buildup and maintaining a well-defined contact situation between the groove and cylinder liner to minimize blow-by and oil loss.
Innovation Solution
A piston ring design featuring conical surfaces with specific angular ranges and a recess-protrusion arrangement in the piston ring groove, allowing for controlled axial and radial movement to prevent oil carbon buildup and ensure effective sealing against gas and oil pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional piston ring design is used, then the structure is simple, but oil carbon buildup occurs and sealing effectiveness deteriorates
Solution Approach 1:
The piston ring is divided into multiple functional zones: a first contact zone with a first angle for primary sealing, a second contact zone with a second angle for oil control, and transition zones between them. This segmentation allows each zone to perform its specific function optimally, preventing both gas blow-by and oil carbon buildup while maintaining overall sealing effectiveness
Solution Approach 2:
The piston ring employs asymmetric angular geometry with different contact angles (first angle and second angle) at different circumferential positions. The first angle differs from the second angle, creating an asymmetric profile that optimizes the contact situation with the piston groove across different operating conditions, improving sealing while controlling oil distribution to prevent carbon buildup
2Reliability
If the piston ring is fixed in the groove, then contact situation is stable, but blow-by increases and sealing deteriorates
Solution Approach 1:
The piston ring design incorporates controlled axial play through the specific angular geometry of the contact zones. The first and second angles are designed to allow the ring to move axially within the piston groove under different pressure conditions, creating a dynamic contact situation that maintains optimal sealing effectiveness while preventing excessive blow-by
3Object-generated harmful factors
If trapezoidal ring with axial play is used, then oil carbon buildup is reduced, but contact situation becomes less defined
Solution Approach 1:
Different zones of the piston ring are assigned different angular characteristics: the first contact zone has a first angle optimized for gas sealing, while the second contact zone has a second angle optimized for oil control. This local differentiation allows the ring to reduce oil carbon buildup in the second zone while maintaining a well-defined contact situation in the first zone for effective sealing
Data Source
AI summary
A piston ring (1) is provided, having a bearing surface (2), an inner surface (4), a lower ring flank (6) and an upper ring flank (8), wherein, at the transition between inner surface and upper ring flank, there is situated a cutout (10) which runs over the circumference and which is in the form of an internal angle, wherein the cutout defines a conical first surface (12a) and a conical second surface (12b) on the piston ring. The first surface is situated, as viewed in a radial direction, further toward the outside and, as viewed in the axial direction, further toward the top, than the second surface. In an axial cross section, a first angle (a) between the axial direction and the first surface lies in the range between 10° and 50°, and a second angle (ß) between the radial direction and the second surface lies in the range between 5° and 30°. Also provided is a piston with a piston ring groove, wherein a projection is arranged on a groove base. Furthermore, a combination of an above piston ring and an above piston is provided, which piston ring and piston are adapted to one another such that the projection protrudes into the cutout.