This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Technology Development to Improve Jatco CVT8 Efficiency
Technical Paper
2013-01-0364
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
This paper explains the developed technologies for improving the efficiency of Jatco CVT8 and the procedures followed in developing and verifying them.
CVT8 has 40% less mechanical loss than the existing base CVT and contributes substantially to improving the fuel economy of the new 2013 Nissan Altima 2.5L.
First, a loss analysis of the existing base CVT revealed that the largest loss factors were the belt-pulley system, oil pump and fluid churning. They were reduced by downsizing the oil pump and lowering the line pressure, followed by optimization of the belt shape and then reduction of churning loss.
Reducing churning loss is not so simple because fluid dispersion also functions to lubricate some parts. Computational fluid dynamics (CFD) was used to design the baffle plate shape and the fluid level. An experiment was then conducted to visualize the fluid behavior, and the results were used to refine the baffle plate shape and adjust the fluid level so as to reduce churning loss while maintaining product quality.
A method was adopted for verifying the fuel economy improvement using motor benches with the HILS. Using this method, a relative evaluation was made of the energy efficiency of the existing base CVT and CVT8 for the same engine and vehicle model during operation under regulatory test driving modes. The results showed that CVT8 contributes to a fuel economy gain of more than 10% compared with the existing unit.
Recommended Content
Authors
Topic
Citation
Shimokawa, Y., "Technology Development to Improve Jatco CVT8 Efficiency," SAE Technical Paper 2013-01-0364, 2013, https://doi.org/10.4271/2013-01-0364.Also In
References
- Mizuochi T. , Shimokawa Y. , Nakao K. , Ohshio S. Introduction of Fuel Economy-related Technologies of a Newly Developed CVT for Midsized to Large Vehicles JSAE 2012 Annual Autumn Congress 1 4
- Imai K. , Nakasone T. , Sugimoto H. New-generation Eco-friendly CVT Series for Middle to Large Vehicles 11 th International CTI Symposium 2012 6 7 10