• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.497-502
• /
• 2004

In this study, we compared the strength of a material used in the A-type disk brake with that in the B-type. From tensile test results, it has been found that the strength of the B-type disk brake is higher than that of the A-type. The microstructure observation and chemical analysis were conducted to determine the cause of the difference between the strength of A and B types of disk brake materials. From the experimental results, it has been confirmed that the difference in the strength between the two types of disk brake is due to the difference in the shape of graphite.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.2
• /
• pp.295-300
• /
• 2007

High temperature superconducting (HTS) windings for an HTS transformer which have been developed have two kinds of type, one is the layer winding and the other is disk winding. The layer winding has adopted for an HTS power transformer so far because of the small AC losses of the HTS windings. The disk windings have surface of the HTS wire. We propose a new winding method for a high voltage HTS transformer which has advantages of both type of HTS windings, and we call it continuous disk winding. This new HTS winding consists of pile of HTS disk windings. The continuous disk winding was fabricated with multi-stacked HTS wires for dover HTS transformer. We can check the potential possibility from the characteristic test of the fabricated winding. The new type HTS windings can be applied to HTS power transformers, especially to the high voltage ones.

• Textile Coloration and Finishing
• /
• v.16 no.3
• /
• pp.39-46
• /
• 2004

This study surveys the physical properties of DTY composite yarns manufactured by pin, disk and belt texturing systems. For this purpose, 208d/36f POY PET and 40d/12f high shrinkable PET filaments are prepared for specimens. The composite yarns are manufactured with this texturized POY and high shrinkable PET filament using the pin, disk and belt type texturing machines. While the processing conditions of the pin and disk types texturing machines were fixed, those of a belt type texturing machine were varied with over feed to compare and analyze with the yarn physical properties of pin and disk type composite yarns.

• Tribology and Lubricants
• /
• v.14 no.1
• /
• pp.28-36
• /
• 1998

This paper presents the thermal behaviours of a solid type disk brake for a high-speed train. The thermal behaviours of a brake disk with 50mm thickness shows good performance compared with 45mm thickness of a disk because of a high specific heat capacity. The FEM results show that the thickness of the disk with a same weight of the brake disk should be increased for a good flexibility of the contact thermal problems. Therefore, the ratio between the pad and disk in diameter may be reduced and the thickness of a disk increased.

• Tribology and Lubricants
• /
• v.14 no.1
• /
• pp.45-53
• /
• 1998

Friction and wear test for two kinds of Cu-based sintered metallic friction material against cast iron disk was carried out by plate-on-disk type friction and wear tester to investigate the friction and wear characteristics of brake system in severe condition. In this experimental study, the counter specimen was cast iron which is being used generally in brakes of heavy duty equipments. Test friction materials were A type which was manufactured by foreign company and B type by domestic company. Friction coefficient and wear volume were measured and compared with each other. The experiment was performed under room temperature. The worn surface of cast iron disk and friction material were observed by scanning electron microscope. The temperature of surface of disk was measured continuously by the non-contacting thermometer. It was found that A type friction material had stable friction coefficient over the wide range of sliding condition, but B type friction material had unstable friction coefficient and lower value of 0.2 under the severe sliding condition.

• Proceedings of the KIEE Conference
• /
• 1998.07f
• /
• pp.1981-1983
• /
• 1998

The principle of the MHD generation is based on Faraday's law of induction that a eletromotive force(u ${\times}$ B) is generated when the working gas of velocity u flows a channel in which magnetic field of strength(B) exists. In MHD power generation system, enthalpy of the working gas is converted to electric power directly through expansion in generator channel. It means that electric power can be generated without moving mechanical linkage such as turbine blades. There are two types in the MHD generator; linear type Faraday and disk type hall generator. Disk type hall generator is the main target of this paper. Isentropic efficiency and enthalpy extraction rate of disk type shock tube driven hall generator is discussed here.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.2
• /
• pp.260-269
• /
• 2000

Oil-film flow visualizations and three-dimensional flow measurements have been conducted in the downstream region of a butterfly-type valve used in air-conditioning systems, with the variation of a disk open angle. The flow visualizations in the flow symmetry plane show that there are a pair of counter-rotating separation/recirculation zones as wall as two jet-like near-wall flows. These flow disturbances are strongly depends on the disk open angle. Based on the flow visualization, a qualitative flow model is suggested in the near-field and downstream region of the valve disk. For a small disk open angle, the mean velocities and turbulent intensities have relatively small values in the near-field of the valve disk, but they do not show uniform distributions even in some downstream region. With an increment of the disk open angle, mean velocity variations and turbulent intensities are greatly increased in the immediate downstream region, but uniform distributions are quickly resumed as departing from the valve disk. The mass flow rate remains nearly constant for the disk open angles less than 30 degrees, meanwhile it strongly depends on the disk open angles between 45 and 75 degrees. The pressure loss is found to be about zero for the disk open angles less than 45 degrees, but is substantially increased for those larger than 75 degrees.

• Tribology and Lubricants
• /
• v.23 no.6
• /
• pp.312-317
• /
• 2007

In general, a brake system of axle for heavy duty machine as a wheel excavator makes use of wet-type multiple disk brakes. These disk bakes are very important parts of heavy duty machine because they are advanced in durability and braking power, and can be designed compactly. Thus, we designed and made wet-type multiple disk brakes of axle for the 14ton class wheel excavator to be localization of these imported all. These disk brakes were made a comparative test with the existing disk brakes by the SAE No.2 dynamometer, and the friction characteristics as dynamic and static friction coefficient and wear depth of friction paper were measured.

• Tribology and Lubricants
• /
• v.25 no.6
• /
• pp.381-386
• /
• 2009

In general, a brake system of axle for heavy duty machine as a wheel excavator makes use of wettype multiple disk brakes. These disk bakes are very important parts of heavy duty machine because they are dvanced in durability and braking power, and can be designed compactly. Thus, we adesigned and made wettype multiple disk brakes of axle for the wheel excavator to be localization of these imported all. In this study, wet multiple disk brakes were made a comparative test with the 3 types materials of friction disk by the SAE No.2 dynamometer. The friction characteristics were measured and analyzed to decide a suitable material as wear depth of friction disk and dynamic and static friction coefficient on temperature of oil and applied pressure.

• Tribology and Lubricants
• /
• v.14 no.4
• /
• pp.29-36
• /
• 1998

The thermal characteristics of a disk such as temperature distribution, thermal behaviors and thermal stress during a braking operation has been analyzed for a high-speed brake using the finite element method. The maximum stress for a pad loaded against a disk was occurred at the trailing and leading edges of the disk pad at the underlayer-backplate interface. The FEM results indicate that the thermal characteristics of the spot type pad shows good performance compared with those of the flat type pad. Thus, the spot type pad in brake system may be recommended for the high-speed train system.