The Proceedings of the Machine Design and Tribology Division meeting in JSME
Online ISSN : 2424-3051
2016.16
Displaying 51-75 of 75 articles from this issue
  • Masahiro FUJII, Shinichiro ABE, Yuya HABARA, Yuji KOBAYASHI, Toshiya T ...
    Session ID: B5-5
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    In order to investigate the effect of laser peening on contact fatigue lives of carburized steel, fatigue test was performed with ball on disk type rolling fatigue testing machine under rolling contact condition. The rolling contact fatigue lives of laser peened carburized steel was compared with those of shot peened or non-peened carburized steels. The substrate of the laser peened steel was little work hardened and the high residual compressive stress was given over a depth of 500 μm. While the rolling fatigue lives of the laser peened steels were not improved under a maximum Hertzian pressure pmax of 6.0 GPa, they were greater than those of shot peened and non-peened carburized steels under a pmax of 5.0 GPa. The surface of the laser peened steel had characteristics of high conformity and kept high residual compressive stress during the rolling process.

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  • Tomoya MIYOSHI, Kazuhiro YOSHIDA, Joon-wan KIM, Sang In EOM
    Session ID: C1-1
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    The authors proposed and developed an MEMS(Micro Electro Mechanical Systems)-based two-DOF (Degree Of Freedom) soft bending actuator for alternating pressure systems. The actuator is driven by ERF (Electro-Rheological Fluid) flows from an alternating pressure source and realizes compact and energy-saving system with high power density. The two-DOF bending motions were achieved by pressure control of four parallel fluidic chambers with high-aspect-ratio reinforcing walls for both large strokes and fast responses. The fabricated 1.9 mm long soft PDMS(poly(dimethylsiloxane)) actuators demonstrated bi-directional two-DOF bending motions and achieved horizontal and vertical displacements of 0.7mm and 1.1mm and blocking force of 0.8 mN with an air pressure of 0.15 MPa.

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  • Tatsuya MATSUBARA, Joon-wan KIM, Shinichi YOKOTA, Kazuya EDAMURA
    Session ID: C1-2
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    This paper proposes the aqueous solution pumping system by ECF jetting and also focuses on the leftover of water to fluidic channels in the system. By utilizing non-mixing characteristics between oil and water, aqueous solution was successfully pumped out by the ECF jetting in the fabricated device. Although measured the flow rate was about 1μl/min at the applied voltage of 0.4 kV, the leftover of water to fluidic channels was observed over 0.2~0.3 kV. In order to solve this problem, we adopt two different approaches: (1) the surface-modification which is hydrophobization; (2) wider channel width (4.5 mm). The wider channel was not significantly effective in this time, while the hydrophobizatin was proved to increase boundary velocity about 172 %(27.8 mm/s) without the boundary break. This study clarifies that the combination of hydrophobization with the enlarged fluid channel has the potential to solve the problem of the water leftover.

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  • Joon-wan KIM, Takuya NAKAGAWA, Shinichi YOKOTA, Kazuya EDAMURA
    Session ID: C1-3
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    This paper presents varifocal liquid lens with integrated ECF micropump. ECF (electro-conjugate fluid) is a kind of dielectric and functional fluid generating strong jet flow (ECF jet) between electrodes surrounded by ECF, when high DC voltage is applied to the electrodes. Pressure by ECF jet changes the boundary geometry of the liquid lens based elastomer membrane. To increase the response time, we propose parallelized TPSEs for higher flow rate of the ECF micropump. We fabricated two kinds of ECF micropumps having 5 pairs of TPSEs in series: (a) 8 pairs in parallel; and (b) 24 pairs in parallel. The experimental results proved that the higher flow rate could be obtained in the parallelization of TPSEs which might have the potential to be adopted in the high-speed response of the ECF variable focus.

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  • Kaito SUMIYA, Yuki SUGINO, Yasukazu SATO
    Session ID: C1-4
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    A switched reluctance motor (SRM) outputs the reluctance torque without the power of permanent magnet. A SRM is generally inferior to a permanent magnet synchronous motor in the point of controllability, torque ripple, and noise. Therefore, industrial applications of SRM as servomotor are limited in some special cases. On contrary, a SRM has advantages of the use in high temperature environment with its robust structure. In recent power-saving hydraulic system, valveless power transmission, in which the flow rate is controlled by a hydraulic pump driven by a permanent magnet synchronous servo motor, has been conducted. In addition, a SRM has recently attracted attention as rare-earth-free motor. In this study, the controllability of SRM has been improved compared to previously developed SRM servo system. Furthermore, hydraulic power control using a hydraulic pump driven by the SRM servomotor has been carried out.

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  • Makoto Naoi, Kei HATAKEYAMA, Toshinori FUITTA
    Session ID: C1-5
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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  • Tomoyasu YAMADA, Takefumi KANDA
    Session ID: C2-1
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    In this study, to generate micro droplets for a chemical manufacturing process, we have designed and fabricated a system using a bolt-clamped Langevin type transducer and the micropore plate in order to generate micro droplets. A diameter of droplet is an important factor and depends on the diameter of the liquid column. Using a pure water and a silicone oil as a dispersed and a continuous phases, the diameter of liquid column was evaluated by experiments. The diameter of liquid column in the case of the liquid column formed in the air, towards the case of liquid column formed in the liquid, the liquid column diameter increases. The relationship between viscosity, surface tension and the diameter has also been discussed.

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  • Takahiro YANO, Takefumi KANDA, Masahiro NAKAZONO, Koichi SUZUMORI, Kiy ...
    Session ID: C2-2
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    In this study, an ultrasonic motor for a solid-state nuclear magnetic resonance (NMR) spectrometer has been fabricated and evaluated. In the solid-state NMR spectroscopy, a sample spinning in high magnetic field is an important factor. The motor is composed of non-magnetic materials and consists of a bolt-clamped Langevin-type transducer (BLT) and a rotor. The diameter and the height of the BLT are 6 mm and 16 mm. The decrease of the motor rotation by the magnetic field was not observed. The solid-state NMR spectroscopy of alanine was measured using the motor under the high intense magnetic field of 7 T. We have successfully obtained a signal of alanine.

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  • Hironari TANIGUCHI, Takumi MEGURO, Shobu ARAKI, Suguru YAMAMOTO
    Session ID: C2-3
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    This paper presents a multifunctional continuous passive movement (CPM) device for finger joints using pneumatic soft actuators. We have developed the CPM device for finger joints which provides not only the range of motion (ROM) exercises such as flexion and extension movements but also to execute a massage therapy for the muscles of the hand and fingers. Basically, the finger rehabilitation is carried out for the thumb through to the little finger. However, the thumb has a higher degree of freedom compared with the other fingers and often undergoes rehabilitation independently. Therefore, we designed the present CPM device so that muscle stretching, flexion/extension and abduction/adduction of the index to little fingers (excluding the thumb) are performed simultaneously. We measured the max ROM needed for finger joints. As the results, we confirmed that the device is able to provide several ROMe xercises.

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  • Shuhei KATO, Masahiro OHKA
    Session ID: C2-4
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    Quantitative evaluation of the concentration degree in psychophysical experiment is required because subjects’ physical and psychological conditions depend on daily status and individuals. In this study, we evaluate the concentration degree of experiments using a tactile mouse developed in previous study and tasks performed for a virtual object using it. For the evaluation, we used electroencephalogram (EEG), near infrared spectroscopy (NIRS) and hemoencephalography (HEG) as brain machine interfaces (BMI). By comparing results obtained from these BMIs, we explored a new effective method to evaluate the concentration degree. Using the tactile mouse, we perform a series of virtual contour tracking tests. As a result, as a common change in brain waves of the subjects, α-wave reduction was observed at the virtual object recognition. Unfortunately, we were not able to find the evidence of concentration from NIRS and HEG. However, this change in brain wave indicates that the subjects are stressed during the recognition, and it may evaluate the concentration degree from the α-wave reduction.

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  • Takuya Shitaka, Noritsugu Umehara, Yousuke Tsukiyama, Isamu Nitta, Mot ...
    Session ID: C3-1
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    A novel lightweight and low starting torque bearing is proposed with looped carbon fibers brush (LCFB). LCFB showed that the static friction coefficient was nearly equal to the kinetic friction coefficient. By applying LCFB as a slide bearing, a ratio of starting torque to regular torque of LCFB slide bearing is from 0.93 to 1.07 which is smaller than that of the slide bearing. When micro-spline shaft is used as a mating material of LCFB slide bearing, the torque reduces because of decrease of real contact area between LCFB and mating materials. We also define the load capacity of LCFB slide bearing by using buckling load of a carbon fiber bundle to avoid overload state.

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  • (Analysis and Experiments on the Static Characteristics)
    Masaya NAKATSUKA, Tomohiko ISE, Toshihiko ASAMI, Kazuhiko NISHIMURA, T ...
    Session ID: C3-2
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    Externally pressurized gas journal bearings with slot restrictors can support large load compared with other types of gas restrictors such as inherent orifices. The authors proposed a new type of externally pressurized gas journal bearing, which has rectangular slot restrictors arranged for axial direction. The bearing with restrictors are formed by two pieces parts, which is connected by screws. Fabricated test bearing has diameter of 30 mm, length of 40 mm and slot width of 16 mm, respectively. This paper reports measured roundness by using 3D-CMM, numerical analysis results by using divergence formulation method and tests results of static characteristics. Obtained results were compared.

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  • (Research of Bearing Characteristics in Ultra High-Speed Rotation)
    Keisuke TERAMAE, Tomohiko ISE, Toshihiko ASAMI, Isturo HONDA
    Session ID: C3-3
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    Hydroinertia gas journal bearings have been used for ultra high-speed rotational machines such as those used in solid state nuclear magnetic resonance (NMR) devices. This type of bearing has inherent orifice restrictors and a large radial clearance compared with conventional externally pressurized gas journal bearings. The large radial clearance makes these bearings suitable for use with a rapidly rotation sample tube (shaft) since instabilities are suppressed by the reduction in hydrodynamic effects. These bearings achieve stable operation for ultra high-speed rotation of spiner shaft at several million rpm. However, solid state NMR devices require a further high speed rotation because of improvement of analysis precision. Therefore, a hydroinertia gas bearing with supply holes inclined in the direction of rotation has been presented. In this bearing, viscous frictional loss is thought to be reduced since this mechanism provides gas flow in the rotational direction. This study reseach practical utillty and the characteristics of this bearings by using a a computational fluid dynamics analysis. This report presents the change of dynamic characteristics of bearings for rotation.

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  • Hiroo Taura, Hiroyuki Yamada, Shogo Ibe, Satoru Kaneko
    Session ID: C3-4
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    We examined a load carrying capacity of circular journal bearings textured uniformly with square-holes on the whole bearing surface with a journal bearing dynamic tester, and the results obtained were compared with the numerical results. The eccentricity ratio for the textured bearings were larger than that of the smooth bearing, and the journal center trajectories for the textured bearings approached to the load line. These results were consistent qualitatively with the numerical results. In addition, the experimental results demonstrated that the effects of the texture on the static characteristics were remarkable when the square holes were small.

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  • Daiki KAWASAKI, Kazuyuki YAGI, Hajime Sato, Joichi SUGIMURA
    Session ID: C3-5
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    In this study, experiments were carried out with the aim to investigate the hydrodynamic lubrication mechanism of moving textured surfaces. The authors observed directly a lubricated area consisting of a rotating glass disc and a stationary glass cylinder from the top of the cylinder. Dimples were created on the rotating glass disc by photolithography. When dimples passed through the lubricated area, the film thickness increased, resulting in reduction in friction. Cavitation was observed within passing dimples. The greater the number of dimples or sliding speed was, the more friction-reducing effect appeared.

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  • -Observation of Gap-
    Hiroaki SHINADA, Yuji ISHINO, Daisuke YAMAGUCHI, Masayuki HARA, Masaya ...
    Session ID: C3-6
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    Currently, pumps are used in various fields to apply air and liquid. These pumps include sliding parts and there is a limit of life time due to friction and wear. To solve this problem, a number of pumps using ultrasonic vibration have been proposed. A common feature of ultrasonic pumps is having no sliding parts. Therefore, the life time of these pumps seems longer than that of the conventional pumps. In the previous study, we found an occurrence of pump effect when an opposing block faces ultrasonically vibrating surface with a small gap. The ultrasonic transducer has a hole to provide the path for fluid flow and the opposing surface was a tapered end of an aluminum cylinder. In this report we observed gap between two surfaces and verify relation ship among the gap, vibration amplitude of transducer and flow rate.

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  • Toshihiro WATANBE, Yasunori SASAZAKI, Yosuke TSUKIYAMA, Isami NITTA
    Session ID: C4-1
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    In a previous study, a novel method for observation of cylindrical surfaces was developed with a laser microscope. With this laser microscope having a wide field of view, cylindrical surfaces can be observed by scanning the focused laser light along the bus direction and rotating the cylinders. However, there is a trade-off relationship between the field of view and the resolution in the depth direction, the resolution of laser microscope with wide field of view became low. In this study, we have supplemented the low resolution in the depth direction by introducing a reference plate. To examine this measurement precision, influences of the image processing and room temperature must be considered. Thus, without the image processing techniques, the surface shape was calculated. In addition, we measured temperature change on the cylindrical surface, and checked that the influence of thermal expansion by comparing it with the observation image.

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  • Takayuki TOKOROYAMA, Shunpei Tanaka
    Session ID: C4-2
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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  • Masato Toida, Hatsuhiko Usami
    Session ID: C4-3
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    The present study describes tribological properties of the textured surface applied with a roll forming process. A chromium alloy steel (SUJ2) disc was used for the specimen. Continuous and discontinues grooves were fabricated on the disc surface. A roller burnishing was applied to the textured surface after the roll forming for truncation. The tribological properties were evaluated with a ring on disc type testing apparatus in lubricated condition. Results showed that the friction coefficient of narrow pitch grooved surface was low and stable. In particular, the friction coefficient was smaller at the beginning of the experiment.

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  • Toshiki SATO, Yasuyuki KANDA, Satoru NISHIO, Hatsuhiko Usami
    Session ID: C4-4
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    Tribological properties of textured surface fabricated with discontinuous micro cutting process were investigated. An aluminum cast alloy (AC8A) disc was used for the specimen. The texturing process was carried out with a CNC machining center with a novel geometry of the cutting edge. The resulted surface morphology consisting from micro dimples having 200-300 μm of the diameter and 5-10 μm of the depth with controlled area fraction of 10 and 40 % and the milling cut finished top region. The tribological properties evaluated with a ring on disc type testing apparatus in lubricated condition showed that the friction coefficient of the textured surface was low and stable from the beginning of the experiment. Dependence of the area fraction of the friction coefficient was also found. It is concluded that the proposed discontinuous micro cutting process is effective means to fabricate micro texture for reduction and stabilization of the friction resistance.

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  • Yasuki Kimura, Hidenori Nagahama, Hiroyuki Nakagawa, Junichi Tada, Tak ...
    Session ID: C5-1
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    In skyscraper buildings, a high-speed and large-capacity elevator is necessary. Usually, spherical roller bearings are used for the traction machine of an elevator. As high-speed and large-capacity cause the large temperature rise in bearings, mechanical loss increases and efficiency of the traction machine decreases. From the viewpoint of environment and energysaving, mechanical loss due to bearings should be decreased. In this paper, in order to reduce mechanical loss of spherical roller bearings, raceway surface properties of the bearing were so improved as to control the slip distribution between a raceway and roller. As a result, temperature rise in bearings could be reduced considerably.

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  • Shoji NOGUCHI
    Session ID: C5-2
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    When a difference of electrical potentials is occurred between the inner and outer rings of rolling bearing, electrical discharge arises inside the bearing. Then, the sound and vibration, which are one of the defects of bearing, from the bearing increase in a short time. This phenomenon is called "electrical pitting". In the raceway surface, a large linear undulation, which can be visual, is formed in the high density after the occurrence of electrical pitting. This undulation is called "ridge mark". It is well known that the ridge mark is a typical damage morphology of electrical pitting. However, there is no report on how the ridge mark is formed on the raceway surface. Therefore, in this research, the authors observed the formation process of ridge mark arising from electrical pitting experiment by using thrust bearing which is very easy to disassemble.

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  • Alan HASE, Kazuho MIZUTA, Yukio NISHIZAWA, Koji SUGIMOTO, Katsuya OKAY ...
    Session ID: C5-3
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    If we could understand the relationship between acoustic emission (AE) signals and frictional properties of brake pads, the complex frictional properties of brake pads could be evaluated from measuring the AE signals. In this study, the relationship between AE signals (mainly, the AE frequency spectrum) and tribological phenomena on brake pad materials was examined by a high-speed in situ observation and AE measurement method. The in situ observation experiments were performed with faster sliding velocity than conventional experiments by sliding a flat tip pin (rotor material) on a block (brake pad material). It was found from the high-speed in situ observations that the microscopic deformation and fracture between the sliding surfaces, a crack growth and separation of brake pad materials, abrasion of the rotor material, and adhesion of metallic fiber to the rotor material, could be identified from the frequency spectrum of the AE signal waveforms.

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  • Masanori TAO, Yoshiro IWAI
    Session ID: C5-4
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS

    This paper reported the detection method of wear amount by our developed sensor. The wear sensor consists of a circuit board and printed conductors. The principle of detection and design of the sensor, together with its performance were reported. The sensor was also designed to improve the conductor detection resolution. The performance of the wear sensor was discussed by the result of sliding wear tests under dry condition.

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  • Akira ITO, Yuka OTSUKA
    Session ID: C5-5
    Published: 2016
    Released on J-STAGE: June 19, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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