Balancing Shaft Inner Ring Segmentation for Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing balancing shaft systems in internal combustion engines face high manufacturing costs and noise issues due to the complexity of bearing design and material requirements, as well as empty spaces that generate noise and friction when using half inner rings.
Innovation Solution
A balancing shaft assembly with an inner ring divided into a semicylindrical body and a half ring, where the half ring is mounted around a semicylindrical portion of the balancing shaft, providing a continuous raceway surface and eliminating empty spaces, allowing for reduced material mechanical characteristics and manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a half inner ring is used in the bearing, then manufacturing cost is reduced, but empty spaces are created that generate noise and friction
Solution Approach 1:
The inner ring is divided into two segments: a semicylindrical body and a half ring. The semicylindrical body fills the empty space on the side opposite the balancing masses, while the half ring is positioned on the side with the balancing masses. This segmentation allows each part to serve its specific function while collectively eliminating the harmful empty space.
Solution Approach 2:
Different portions of the inner ring have different structural characteristics tailored to local requirements. The semicylindrical body provides full coverage on one side, while the half ring provides targeted support on the other side where balancing masses are located. This local differentiation optimizes both noise reduction and load-bearing capabilities.
2Object-generated harmful factors
If the inner ring covers 360° to eliminate empty spaces, then noise and friction are reduced, but manufacturing cost increases
Solution Approach 1:
Rather than using a complete 360° inner ring, the solution segments the inner ring into two parts: a semicylindrical body and a half ring. This segmentation eliminates the need for a full circular inner ring, reducing material usage and manufacturing complexity while still achieving continuous raceway coverage.
Solution Approach 2:
The bearing structure applies different configurations to different regions: the semicylindrical body covers the region opposite the balancing masses, while the half ring covers the region with the balancing masses. This local quality approach ensures noise reduction is achieved only where necessary, optimizing cost-effectiveness.
3Reliability
If the balancing shaft material has high mechanical characteristics to form bearing surfaces, then bearing performance is improved, but manufacturing cost increases
Solution Approach 1:
The bearing function is segmented from the balancing shaft. Instead of requiring the entire balancing shaft to have high-grade bearing material, only the half ring portion needs bearing-grade material, while the semicylindrical body can use less expensive materials. This segmentation allows cost optimization while maintaining bearing performance.
Solution Approach 2:
High mechanical characteristics are applied locally only where necessary - specifically in the half ring that contacts the rolling elements on the balancing mass side. The semicylindrical body portion can use materials with lower mechanical characteristics, reducing overall material cost while maintaining bearing performance at the critical interface.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
This balancing shaft assembly (A) comprises a balancing shaft (1) rotatable with respect to a housing (H) around a central rotation axis (X-X'), at least one bearing (B) allowing the rotation of the balancing shaft (1) with respect to the housing (H), each bearing (B) comprising an inner ring (2) coupled in rotation to the balancing shaft (1), an outer ring (6) fixed with respect to the housing (H), and rolling elements (8). The at least one bearing (B) is mounted on a bearing area (3) of the balancing shaft (1). The inner ring (2) is divided into a first portion formed by semicylindrical body (11) mounted against the bearing area (3) of the balancing shaft (1), and a second portion formed by a half ring (15) mounted around a semicylindrical portion (302) of the bearing area (3) of the balancing shaft (1), the inner ring (2) having an outer raceway surface (2A) formed by a semicylindrical surface (9) of the semicylindrical body (11) and by a semicylindrical surface (13) of the half ring (15). The half ring (15) has an outer radius (R15) equal to the outer radius (R11) of the half cylindrical body (11).