Development aims
Reduce the amount of leaked oil (assuming that the amount of oil required by the bearing is secured)
→Enable the capacity of the oil pump to be reduced to help improve fuel economy
![](/assets/media/2023/04/img-round_eccentric_groove-1.jpg)
Development concept
Reduce the amount of oil leaked from the main bearing by improving the form of the groove in the main bearing (from trapezoidal to R shaped)
Base (Semi-circular groove)
![](/assets/media/2024/05/img-round_eccentric_groove-2_en.jpg)
![](/assets/media/2024/05/img-round_eccentric_groove-3_en.jpg)
Current products(Eccentric groove)
![](/assets/media/2024/04/img-round_eccentric_groove-4_en.jpg)
![](/assets/media/2024/05/img-round_eccentric_groove-5_en.jpg)
Groove depth is reduced gradually
→Reduce side flow
Developed product
![](/assets/media/2024/04/img-round_eccentric_groove-6_en.jpg)
![](/assets/media/2024/04/img-round_eccentric_groove-7_en.jpg)
Gradual reduction in groove depth is accompanied by a gradual reduction in groove width
→Side flow is further reduced
Performance
Oil leakage amount
![](/assets/media/2024/05/img-round_eccentric_groove-8_en.png)
Improved fuel efficiency 0.04%(Estimated value compared to current products with eccentric groove)