Combined Oil Ring Segment Structure to Prevent Independent Rotation
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Solution Overview
Problem
Existing combination oil rings for internal combustion engines face issues with independent rotation of segments, leading to increased oil consumption due to gaps between segments, and current solutions either fail to prevent rotation effectively or are costly in terms of manufacturing.
Innovation Solution
The implementation of dross-projecting portions on the inner peripheral surface of the segments, which are inclined and formed across recessed grooves, prevent independent rotation by engaging with the expander spacer's ear portions, while being cost-effective and manufactured through in-line processing without increasing the number of steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If tension of the combination oil ring is reduced to decrease friction, then fuel consumption is improved, but segments perform individual rotation in circumferential direction causing excessive oil supply
Solution Approach 1:
The inner peripheral surface of the segment is designed with asymmetric features including inclined fine projections and recesses that create directional engagement with the expander spacer ears. This asymmetric geometry prevents circumferential rotation by ensuring that the segment can only engage in one rotational direction, thereby maintaining reliable oil control while allowing reduced tension for lower friction.
Solution Approach 2:
The fine projections and recesses are pre-formed on the inner peripheral surface of the segment during manufacturing. This preliminary action ensures that when the segment is installed with reduced tension, the anti-rotation mechanism is already in place and functional, preventing individual rotation before it can cause oil control issues.
2Reliability
If machine work is performed on inner periphery of the segment to form fine projections and recesses, then individual rotation is prevented, but working stress affects circularity of the segment
Solution Approach 1:
Instead of using traditional machine work that applies high localized stress, the patent changes the manufacturing parameters by forming fine projections and recesses through processes that distribute stress more evenly. The projections and recesses are designed with specific dimensional parameters (fine scale, inclined geometry) that achieve rotation prevention while minimizing impact on overall circularity.
3Length of moving object
If segment width is reduced to reduce combination oil ring width, then space is saved, but breakage caused by machine work on inner periphery increases
Solution Approach 1:
The patent changes the manufacturing approach by forming fine projections and recesses with optimized dimensional parameters that reduce the severity of working stress. The inclined geometry and fine scale of these features allow them to be formed without creating stress concentrations that would lead to breakage in narrow segments.
4Reliability
If surface treatment is performed on inner peripheral surface of the segment, then rotation prevention is achieved, but manufacturing cost increases
Solution Approach 1:
The patent merges the formation of fine projections and recesses with the existing manufacturing process for the segment. Instead of adding a separate surface treatment step, the anti-rotation features are integrated into the primary manufacturing process, thereby achieving rotation prevention without increasing manufacturing cost.
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
This configuration effectively prevents independent rotation of segments, reducing oil consumption and maintaining the required quality while minimizing manufacturing costs by using carbon steel or stainless steel and optimizing the projection height and inclination angles of the dross-projecting portions.
Implementation Method 1
an inner peripheral surface of a segment in contact with an expander spacer has fine projections and recesses
Data Source
Figure 1~2
Figure 3~4
Figure 5~7
AI summary
Provided are a segment, a combination oil ring, and a manufacturing method for a segment, which are capable of preventing independent rotation of the segment while dealing with reduction in tension of the combination oil ring. Specifically, provided is a segment (20, 30) being slidable in an axial direction of a cylinder (1) under a state in which an inner peripheral surface (22, 32) of the segment is pressed by ear portions (43) formed in an expander spacer (40) in a circumferential direction and an outer periphery side of the segment is pressed against an inner wall of the cylinder (1), in which the inner peripheral surface (22, 32) of the segment (20, 30) has at least two or more dross-projecting portions (26, 36) in the circumferential direction, and the dross-projecting portions (26, 36) have a projection height of from 4 µm to 25 µm.