The gear unit of the Tokaido Shinkansen have been installed a parallel cardan driving device since the 0-series, and the gear has been a helical gear. In N700S’bogie, we reduced the weight of various elements considering the running safety, the bogie hunting, the ride quality and the ground vibration. Utilizing the weight saving effect, we incorporated the double helical gear device with somewhat heavier weight but have extremely high reliability. It is the first time that the double helical gear is used in high speed commercial vehicles. Through the field tests and bench tests, etc., we confirmed that the developed double helical gear device has a higher performance compared with the conventional one.

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A gear oil with improved low-temperature fluidity has been developed for Shinkansen vehicles used in cold districts. In this gear oil, much lower low-temperature viscosity and a higher viscosity index than the current gear oil have been achieved by using highly refined mineral oils as a base oil, and newly adding viscosity index improver additives. It has been indicated from performance tests that the gear oil developed has oxidation stability and lubricating performance equal to or higher than those of the current gear oil. The gear oil developed shows enough fluidity at -30°C in bench rotation test, and enough durability performance in on-track verification tests on Shinkansen vehicles. It has also been confirmed from rotational test of small tapered roller bearing that rise in temperature of the gear oil developed is lower than the current gear oil.

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Drive system noise of conventional line vehicles tends to decrease due to popularization of low noise type motors. As a result, the gear noise seems to be relatively high level. It is considered that the main vibration source of gear noise generated during power running is variability force due to gear meshing. In order to reduce the vibrations, we are studying the application of high strength ductile cast iron (H-FCD) to vehicle traction gears. The iron has excellent material damping performance. We made the prototype gear of conventional line using H - FCD 1000. In this paper, we describe the result of comparing the noise performance of conventional steel material gear with this one.

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Battery train is in development as train which can travel in non-electric section using power supplied from onboard storage system such as lithium-ion battery. However, as characteristics of this type of train, an energy consumption of battery train depends on the state of charge of the storage system. In consideration of these characteristics, in this research, we propose a generation method of the timetable which is the most energy-saving when a single battery train travels on a route section containing multiple stations. Although this optimization can be defined as a nonlinear programming problem, we ease to solve this problem using linear approximation to the energy consumption characteristic. In the end, we carried out a simulation in a simple case and achieved 4.7% reduction in energy consumption by the proposed method.

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For the energy saving of DC-electrified railway, the regenerative brake which is able to transmit braking power to other powering train is key technology. However, the availability of regenerative brake depends on the state of other trains such as position, speed and power. Therefore, some parametric study for the difference of regenerative energy due to train operation and station distance is held in this report.

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Regenerative brake is one reason of the superiority of railways compared with other transport modes. The brake energy is reduced or cancelled when enough load to consume energy is not exist near the braking train. From the view point of saving energy consumption, it is desirable to avoid the wasteful situation. Thus recently energy storage equipment on the ground was developed by various railway companies. This year, first case to put such equipment on board is developed by Keio electric railways. We have studied which way has better cost benefit ratio for various cases.

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Railways have superiority in higher energy efficiency and lower environmental load compared to other transportation agencies. In order to realize superiority at a higher level, we are making efforts to reduce driving energy, such as adopting a SiC applied traction system for the next Shinkansen “N700S”. Generally, the method of energy-saving driving is said to be maximum acceleration, coasting, and maximum deceleration. However, it is difficult to utilize coasting over long distances at high speed because the high speed rail connecting the cities such as the Shinkansen has a long distance between the stations and the running resistance increases in proportion to the square of the speed. Therefore, it is difficult to apply this method, and the method of energy-saving driving for the high speed rail has not been established. In this research, we focused on equipment efficiency of the Shinkansen in energy-saving driving suitable for high speed rail conditions. We simulated the notch control in consideration of equipment efficiency using a model case of the ground condition and the diagram, and examined the effect of equipment efficiency on driving energy.

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The plates that cover the underside of trains have roughnesses, which are often caused by joints, bolt heads, and other fabricationbase issues. Comparing bogies of trains, their height is very low, and their aerodynamic drag is similarly very small. However, there are many roughnesses on the underside of the train. Therefore, the total drag of these roughnesses may not be quite so small. However, there are a limited number of studies regarding roughness drag. Therefore, we propose a method for measuring the drag of these roughnesses on the underside of a train vehicle and estimate the drag. Results of this study indicated that their maximum drag reached 5.9% of the total aerodynamic drag of the train vehicle.

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Recently, compound semiconductor devices such as SiC devices have been developed for inverter systems of electric railway vehicles. They realize lower switching loss than conventional Si devices. This paper clarifies the effect of SiC semiconductor switching devices for propulsion systems of EMU with two examples. The first example shows the direct benefit which reduces loss of switching devices and it contributes to miniaturize an inverter. The other example shows the indirect benefit which can reduce energy consumption by changing the regenerative brake pattern to increase regenerative energy. Finally, this paper suggests the potential that IGBT inverter systems can reduce energy consumption same as the SiC inverter system.

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In this study, we developed a traction system for high-speed trains by adopting SiC power devices to pursue weight reduction and compactness of the system. We found the combination of the SiC applied conversion system with train-draft cooling system and 6-pole induction motors is a suitable approach to highlight the merits of SiC devices. The developed traction system is installed in the Series N700S Shinkansen. Furthermore, we tried to drastically reduce inspection time and load by utilizing state monitoring and self-diagnosis functions.

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When a train passes through the rail joint at the heel of the tongue rail in a railroad switch, an impact vibration is generated. This vibration is transmitted to the front rod, which causes wear of bearings or fatigue of parts called “hook”. Accumulation of the wear or the fatigue can lead to switching failure. Especially, there are a lot of cases in which the hook fatigue and break around the fastening bolts. In this research, we focused on the fatigue of the hook. We have developed the FE model of the railroad switch, simulated the vibration, and evaluated the reliability of the railroad switch. Our final goal is to propose the appropriate maintenance schedule for railroad switches under various working conditions.

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The motor point machine is very important equipment for train operation. Failure of the machine is directly linked with transport suspension. Therefore, it is extremely essential to prevent failure of the machine. We examined some analysis method which may detect the signs of failure so as to maintain the machine before failure occurrence. We developed NS type motor point machine and switch adjuster with sensors which acquire corresponding data for being able to failure prediction. We developed the analysis machine with several failure prediction methods by using the monitoring data from motor point machine.

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The lock warp causes the switching machine serious troubles which affects stable railway transport. The lock warp happen when rock rod displacement exceeds the permissible amount due to the thermal expansion caused by the varying weather conditions. In this paper, we examine a method of predicting rock rod displacement caused by the various weather conditions. In this method, firstly we construct a model of predicting the temperature of the switch-and-lock system based on the weather conditions by multiple regression analysis, and then we estimate the rock rod displacement based on the geometric model of the switch-and-lock system together with the temperature model.

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Concrete pole had been generally used as signal pole since mid 20c. Those are widely spread, however the metrology of repair and renewal is not established now. In this paper, we reports about characteristics (shape, number of reinforced bar) of signal poles by age which has been missed by ageing deterioration. Moreover, we reports field survey results which aim for confirming relationship between deteriorations on a pole and age and location. We confirmed that percent of the deteriorations of poles at shore in Northern Sea of Japan is higher than poles at inland by the results of the field survey.

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Concrete signal poles have been used on the railways on a wide scale for over 50 years. For determination whether a pole needs to be replaced or not, it is critical to detect a pole without enough strength. Today, this is done only through visual inspections. Therefore, criteria for judgement of deterioration level of poles is desired in order to formulate adegulate update plan. On this stury, bending strength test of concrete signal poles was conducted, and the relationship between deterioration and strength decrease was clarified.

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