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Prediction of Friction Durability in Off-Road Applications Based on Mechanistic Understanding of the Effects of Fluids and Surfaces on Clutch Friction

Komatsu Ltd.-Shinpei Kariwa, Toshiharu Abekawa
Afton Chemical Corporation-Mark Devlin, Atanu Adhvaryu
  • Technical Paper
  • 2019-01-2339
Published 2019-12-19 by SAE International in United States
After new transmission lubricants are developed there is an extensive validation program where friction durability testing is performed on multiple clutch materials. Each durability test can run for long terms and the entire validation program can take much longer terms. A well designed lubricant and friction material will deliver the necessary friction control for construction equipment to operate at optimum level. A mechanistic construct has been evaluated to calculate friction durability in clutch systems based on fluid and surface tribological properties. Fluid properties include both boundary frictional and rheological effects. Surface properties include elastic modulus, surface roughness, asperity density and asperity tip radius. Using this mechanistic construct friction durability has been predicted. In the past, researchers in the field have often associated lubricant induced glazing of the friction material surface as the cause of the loss of friction control in clutch systems. In the current study, results show that wear is also a dominant cause of friction loss. In short clutch friction tests the rate of change in surface properties and fluid properties have been…
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Full-Load HCCI Operation with Variable Valve Actuation System in a Heavy-Duty Diesel Engine

Komatsu Ltd.-Yuuichi Kodama, Izumi Nishizawa, Takumi Sugihara, Norihiko Sato
Industrial Power Alliance, Ltd.-Tadashi Iijima, Tatsuya Yoshida
Published 2007-04-16 by SAE International in United States
Full-load HCCI operation with extremely low emissions was demonstrated. Experiments were performed on a 1.8L single cylinder heavy-duty diesel engine equipped with variable valve actuation system. Extensive study was made for the effects of EGR ratio, intake manifold temperature, air-fuel ratio and intake valve close timing on HCCI operation. With appropriate selection of the above variables, operation range was extended up to 2.0MPa of IMEP with diesel fuel. NOx emission was extremely low (0.01g/kWh) with retaining low smoke level (0.1BSU).
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Simultaneous Reduction of NOX and Soot in a Heavy-Duty Diesel Engine by Instantaneous Mixing of Fuel and Water

Komatsu Ltd.-Taisuke Murotani, Kazutaka Hattori, Etsuro Sato
University of Michigan-Christos Chryssakis, Aristotelis Babajimopoulos, Dennis N. Assanis
Published 2007-04-16 by SAE International in United States
Meeting diesel engine emission standards for heavy-duty vehicles can be achieved by simultaneous injection of fuel and water. An injection system for instantaneous mixing of fuel and water in the combustion chamber has been developed by injecting water in a mixing passage located in the periphery of the fuel spray. The fuel spray is then entrained by water and hot air before it burns.The experimental work was carried out on a Rapid Compression Machine and on a Komatsu direct-injection heavy-duty diesel engine with a high pressure common rail fuel injection system. It was also supported by Computational Fluid Dynamics simulations of the injection and combustion processes in order to evaluate the effect of water vapor distribution on cylinder temperature and NOX formation. It has been concluded that when the water injection is appropriately timed, the combustion speed is slower and the cylinder temperature lower than in conventional diesel combustion. The result is drastic NOX reduction with a simultaneous decrease of soot emissions. The computational results are in agreement with experimental measurements and provide detailed information…
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JCMAS New Grease Specifications for Construction Machinery

Komatsu Ltd.-Satoshi Ohkawa
Afton Chemical Japan Corporation-Masao Seki
Published 2006-10-31 by SAE International in United States
Since construction machinery manufacturers recommend various brands and types of greases for their machinery, customers would benefit from a standardized grease which can be used in all construction machinery. Furthermore, construction machinery manufacturers have many experiences of field problems caused by commercially available and commonly used EP Lithium greases. Therefore, the Fuels and Lubricants Committee of Japan Construction Mechanization Association (JCMA) has developed a new grease specification called “Japan Construction Mechanization Association Specification (JCMAS) GK,” for construction equipment. The JCMAS GK includes requirements for National Lubrication and Grease Institute (NLGI) No. 1 and No. 2 consistency grades. The JCMAS GK greases have enough lubricating properties for periodical grease fitting of most construction machines, hydraulic excavators, bulldozers and wheel loaders. The JCMAS GK greases are applicable from -20 to +130 degrees Celsius. The JCMAS GK greases can also improve nitrile and urethane seal durability. Finally, a biodegradable grease specification was established, JCMAS GKB, was established for construction machinery.
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Development of New Hydraulic Fluids Specifications for Construction Machinery

Komatsu Ltd.-Satoshi Ohkawa
Afton Chemical Japan Corporation-Masao Seki
Published 2005-11-01 by SAE International in United States
Hydraulic fluid (HF) specifications for mobile construction equipment called JCMAS HK and HKB have been established by the Fuels and Lubricants Committee of Japan Construction Mechanization Association (JCMA). The specifications are designated by two viscosity categories of single grade and multigrade.Each category has ISO viscosity grade (VG) 32 and 46. The JCMAS HK oils are recommended for use in hydraulic systems designed at pressure up to 34.3MPa(5000psi) and to heat hydraulic fluid up to 100 °C. These oils also provide wear control, friction performance, oxidation and rust protection, seal swell control and filterability performance. Two piston pump test procedures were developed to evaluate lubricating performance of these oils under high pressure conditions. The JACMAS HKB oils are classified as environmentally friendly oils due to the additional requirement for biodegradability.
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New Standard for Four-stroke Diesel Engine Oils: JASO DH-1

Komatsu Ltd.-Satoshi Ohkawa
Chevron Oronite Japan Ltd.-Takayuki Narishima
Published 2001-05-07 by SAE International in United States
This paper reviews the development of a new standard for four-stroke diesel engine oils, JASO DH-1 (JASO M355: 2000). This standard was introduced to the market on April 1, 2001. It prescribes the minimum performance for engine oils conforming to four-stroke diesel engines manufactured by Japanese OEMs. This standard is composed of four engine tests and seven bench tests. The engine tests include a piston detergency test (JASO M336: 1998), valve train wear test (JASO M354: 1999), soot dispersancy test (ASTM D 5967-99) and high temperature antioxidation test (ASTM D 5533-97a). The piston detergency test and the valve train wear test were developed in Japan. The bench tests measure hot surface deposits, anti-forming, volatility, anti-corrosion, shear-stability, total base number, and seal compatibility.
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Numerical and Experimental Methods to Investigate Cooling Air Flow in the Construction Machinery's Engine Compartment

Komatsu Ltd.-Toshikazu Nakanishi, Sanshirou Shimoda
Kyushu University-Nobuhiko Yamasaki, Yuzo Inokuchi, Tsuyoshi Takemoto, Hisashi Okazawa
Published 2000-09-11 by SAE International in United States
This paper describes 3-dimensional computational fluid dynamics analysis to estimate the air flow in the construction machinery's engine compartment and accompanying measurements. As the computational grid, tetrahedral cells with rotating reference frame fixed to the fan were used. In the measurement, the single yawed hot wire rotation method was used to measure the 3-dimensional velocity vectors. As a result, the measured values correspond well to the computational results.
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Dynamic Stress Analysis of a Dump Truck

Komatsu Ltd.-Toshihide Shibuya
Estech Corp.-Seiji Aoyama
  • Technical Paper
  • 988029
Published 1998-05-20 by Society of Automotive Engineers of Japan in Japan
Assessment of dynamic stress has been an important task within the design process of machinery. Especially for design of off-road dump trucks, it has been a vital step.The task of assessing structural strength had been performed via testing of existing vehicles. However, in order to perform such a task for a number of specifications, it requires a considerable amount of time. This paper describes a new method for estimating dynamic stress by utilizing commercially available CAE software. Application of the method to predict dynamic stress of an off-road dump truck is also described.
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The Millimeter-Wave Radar for Construction Machines

Komatsu Ltd.-Yasuo Kitahara, Taku Murakami
Fujitsu Ten Ltd.-Shin-ichi Yamano, Toshiki Yamawaki
Published 1997-09-08 by SAE International in United States
Importance of detecting obstacles around construction machines increase rapidly. The millimeter-wave radar is the most useful sensor to keep to detect obstacles in the current technologies. because of its good performance under severe conditions. The signal processing algorithm of this radar is developed, for the using in working conditions by means of eliminating signal fluctuations and instabilities caused by its environments. The developed millimeter-wave radar has a reasonable performance, for example, detecting the rear side of automobiles and many types of construction machinery from the distance of 100m.
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Precision Angle Sensor Unit for Construction Machinery

Komatsu Ltd.-Taku Murakami
NTN Corp.-Masahiro Kato, Michio Ota
Published 1997-09-08 by SAE International in United States
Small swing-radius hydraulic excavators are often used in narrow construction areas, especially in cities. Operators are required to control the movement of the machine very accurately so as not to damage utility wires, trees, advertising signs, gas lines, underground electric wiring, water mains, and so on. The excavators are designed to warn the operator or stop completely when the machine comes close to a known hazard. To perform this function, the machine must be able to accurately monitor the location of the bucket and boom.Angle sensors are put on the joints of the arms and boom to monitor their angles. The bucket position can be calculated with the sensor outputs. Accuracy and rigidity are the most important features for these sensors. Additionally they must be rugged enough to survive in a severe construction environment.The sensor unit has a potentiometer with +/-0.5% independent linearity. It is directly attached to the shaft end which is supported by two pre-loaded precision ball bearings. This arrangement allows little displacement between the brush and resistor of the potentiometer. Because of…
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