This section introduces the research subjects and research system of industry-academia collaboration promoted by the Internal combustion engine technology research association. In addition, the outline of researches on engine tribology, such as friction loss reduction, fuel oil dilution, and lubricating oil consumption, and the features of the engine and bearing tester used in these studies are described.
In order to reduce CO2 emission, motorcycle has so far improved the fuel economy by improving brake thermal efficiency of engine, optimizing driving condition, and reducing running resistance. For improving brake thermal efficiency of engine, the main methods are improving combustion efficiency i.e., improving combustion and mechanical efficiency i.e., reducing friction. Specifically, they are enhancement of in-cylinder flow, fuel injection system, offset cylinder, roller rocker arm, coating molybdenum disulfide onto the piston skirt, and etc. For optimizing driving condition, they are down speeding of engine, idling stop system. And for reducing running resistance, it is low fuel consumption tires. Moreover, In order to reduce the friction of motorcycle engine furthermore, various methods were innovated; modifying the striation finish on piston skirt, adding the needle bearing to the rocker arm shaft, press-fitting the bush into the small end of connecting rod, low viscosity oil for motorcycle, and variable cooling system for scooter engine. By innovating these friction reduction methods, the fuel economy was improved compared with each base model.
In recent years, friction reduction of piston rings is said to be the limit. This is because the LOC increases as the friction force decreases. Piston ring material technology has evolved. The spread of PVD and DLC has progressed. On the other hand, research on frictional force has not progressed much. As a result of relying solely on tension reduction to reduce frictional force, LOC deteriorated. This explanation examines recent evolution of piston rings. Based on these, It is summarized that the limitations of the current technology and issues for further friction reduction.
Saving fuel consumption has been strongly demanded for several decades, and friction reduction is one of the key to achieve that. In this Explanation, advanced designs and materials of radial shaft seals, which contributes to better fuel consumption, are described. Latest developments on minimizing radial load of rubber lip, reducing friction coefficient between the lip and the shaft and adapting low viscosity oil are explained.
In recent years, the electrification of automobiles and the reduction of fuel consumption have been promoted against the background of environmental problems. To reduce power consumption, reduce size and weight, increase speed, and reduce torque for automotive parts various efforts have been made. In this article, we will introduce the technical trends of AT, HV, EV needle roller bearings and and tapered roller bearings that have been introduced in recent years with the keywords of small size, light weight, low torque, high speed and quietness.
While the world’s fuel economy regulations are getting stricter year by year, turbochargers are contributing to fuel consumption reduction. This review describes the design technology that has been introduced so far and the future issues of rotors and bearings. Technical topic of electric turbocharger, which corresponds to the vehicular electrification, is also introduced.
This explanation describes examples of fuel economy improvement technologies that have been applying engine bearings. In order to improve the fuel economy of automotive, it is very important to reduce the friction of engine bearings, and many technologies have been applied. The method as means low friction, by reducing the amount of oil to the engine bearings, the smaller the oil pump capacity, reducing the torque throughout the engine system, and coating a solid lubricant on the surface of the bearing, there is a method of reducing the friction at the time of starting the engine is stopped. Furthermore, in order to reduce the fluid friction during cold, a technology that realizes an early temperature rise of the oil film interposed between the crankshaft and the bearings is used. In this paper, these technical examples are introduced, and finally, future technical trends and prospects for engine bearings are described.
According to the Permission Standard for Cosmetic Products 1999, cosmetics are classified into 11 types, such as basic cosmetics and cosmetics for cleaning, and the basic cosmetics have been formulated so as to compensate for the deterioration of moisturizing function of the stratum corneum. On the other hand, in recent years, ceramide has formed a layered structure in a corneal layer, so that component having a barrier function against stimulation has been incorporated. Since ceramide is a trace ingredient in the Natural world, it was found that the barrier function was restored by measuring the TEWL change in continuous use by using Sodium Dilauramidoglutamide Lysine having a similar structure to ceramide. On the other hand, cosmetics for cleaning contain ingredients for removing soil, but excessive detergency leads to deterioration of skin function and skin irritation and therefore,amino acid surfactants having appropriate detergency have been used. Though there are many problems such as foaming and viscosity, it was found that the problem can be solved by examining the optimum ratio.