LIGA (German acronym for Lithographite Galvanoformung and Abforraung) process, that utilizes a useful industrial application of synchrotron radiation (SR), is one of the promising technologies for fabrication of extremely tall three-dimensional (3D) microstructures with a large aspect ratio. This process leads to application of raicro-nano fabrication technology. As research and development in various fields such as micro-mechanics, micro-optics, sensor, actuator are promoted. Furthermore, the demands for micro devices produced by IT, chemical, medical, and biological technologies will be greatly increased. Focusing on the economical mass production on the micro devices, precision plastic reproduction techniques such as hot embossing and injection molding are essential techniques. This paper describes recent advantages and prospects of raicro-nano systems composed by these micro devices and its fabrication.

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High performance robots working in future human daily life should have not only excellent intelligence but also motion flexibility. Thus new type robots with hyper redundancy should be developed. This paper describes the features and subjects of such hyper redundant robots, and introduces several research works especially on mechanisms and control method for the robots by the author.

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Recently, nanotechnology is regarded as very important for 21st century industries. Industrially advanced nations, which include USA and Japan, have been making efforts to develop nanotechnology and to build up nanotechrbusiness systems. Especially in USA and Japan, budgets more than 800M$ were invested to the nanotechnology in 2003. In this paper, I will show such a background of nanotechnology and clarify the problems Japan has in the near future.

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In a sandwich-belt conveyor there are tow belts, one is driving belt and another driven belt, used to pinch and convey media. Finite elements analysis and experiments are carried out in this paper for investigating belt tensions and slip of belt and pulley. The cross sectional structure of real rubber belts is considered in the FEA. It is found that the gross slip between the two belts will influence the belt tensions, but the position of pitch line of the belt does not. Also it is found that the speed delay of pulley and belt of driven side is made up of two parts: bending slip due to belt bending and elastic slip due to torque load.

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Helical synchronous belt drives are more effective than conventional synchronous belt drives with respect to reducing noise and transmission error per single pitch of the pulley. In the present study, the transmission error in helical synchronous belt drives under transmission torque was investigated experimentally for the case where the pulley was rotated in bidirectional operation. In this case, the transmission error that does not occur under no transmission torque is found to be generated when the transmission torque acts. The transmission error does not occur when the pitch differences on the driving side and that on the driven side are selected so that the belt tooth loads at both the beginning of meshing on the driving and driven sides become equal.

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Synchronous belt is used for the robot arm in order to carry FPD and wafer because it can be reduced weight, noise, and energy loss. However, it is known that the transmission error is generated by essential meshing between the belt and pulley teeth. In the present study, the transmission error in synchronous belt under the installation tension and quasi-static conditions was investigated both analytically and experimentally when 1st arm is rotated in bidirectional operation. In analysis of transmission error, ABAQUS version 6.3 was used. The computed transmission error agrees with the experimental results, confirming the applicability of the proposed analysis model for transmission error. It is found that the transmission error is generated by the change in contact state between the belt and pulley tooth flanks. When the pitch of fixed pulley is small and that of driven pulley is large, transmission error can be reduced.

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Synchronous averaging method is applied to extract the signal attributed from driving and/or driven gear from each other. Some concepts about signal processing used in synchronous averaging method are discussed here. From the results, it is recommended that the length of each block of the signal that will be averaged should be selected to fit with the period of driving or driven shaft revolution. In this case, rectangular window is used instead of the other window functions. Shaft order analysis is applied for extraction vibration components at each shaft order from the vibration waveform. With these processes, the more precision in amplitude and frequency of vibration results are obtained. The effect of the number of averaging is also discussed.

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Utilization of synchronous averaging enables to point out which gear shaft of a gear system is the origin of 'ghost noise' that is not integer order of mesh frequency. But when plural gears are on a shaft generating ghost noise, it is difficult to point out which gear is the origin. In this study, we propose detection method of trouble gear utilizing amplitude fluctuation analysis. Proposed method is verified with vibration measurement result of two-stage gear reduction system.

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Damping parameters for a gear system is difficult to measure directly because its excitation force with gear meshing can't be measured. This paper introduces an experimental identification method of damping coefficients of 3DOF vibration model for a power transmitting gear system as a basis of multi DOF vibration analysis. In the proposed method, modal analysis is performed with measured vibration response and we can obtain 3DOF damping coefficients, meshing part damping coefficient and transverse coefficients of driving and driven gear shaft, without any trial and error process. And the analyzed damping coefficients are verified experimentally with a gear test rig in which the damping effect can be change.

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Two types of super gears with small transmission error regardless of tooth loads are proposed. One is a zero-transmission-error gear (ZT gear) the tooth surface of which is modified three-dimensionally. The other is a meshing-restriction-gear (MR gear) the tooth tip of which cut off the tooth tip obliquely to control tooth stiffness. Both gears were made and their vibration and noise were examined. It was confirmed that both gears bring low noise and low vibration characteristics.

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A planetary gear train is used as a transmission in many fields, because it has a smaller size, a lighter weight and has a larger gear ratio than a conventional gear train. However, the planetary gear train can not drive because of a significant low efficiency. In this study, we theoretically analyzed the efficiency of 2K-H type planetary gear train and presented the condition in which the self-locking occurred. Furthermore, we examined the self-locking of 2K-H type planetary gear train using several gear sets with different teeth number by the running test. As the result, the condition of the self-locking that was analyzed theoretically agreed approximately with experimental result.

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The crossed axle traction drive developed by authors has been applied to the Shaft Drive CVT (S-CVT). The proper design of crossed axle traction drive is required to improve the efficiency of S-CVT. In this paper, the theoretical power-transmitted efficiency is examined using a shear model of traction in EHL contact area. The traction coefficient decreases due to the spin and large contact pressure. The relation between traction curve and sizes of disk and roller is obtained and it is useful to design the crossed axle traction drive. The result of calculation gives good agreement with the result of experiment.

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When the Finite Element Method is applied to the stress analysis of meshing tooth pair, a large difference between dimensions of finite elements and tooth flank modification should be one of the main issues. In addition, it is very difficult for FEM to solve a contact problem in meshing part. A new element for representing boundary condition at contact area, a Tooth Flank Film Element, was proposed as a solution to the issues. Contact area is supposed, then the Tooth Flank Film Element enables distributed loads to be given to the area. A CAE system specialized for static stress analysis of cylindrical gear pair has been developed using the Tooth Flank Film Element. The present paper describes the developed CAE system. Because the CAE system is specialized for cylindrical gear pair, it is very easy to construct the analytical model which can include tooth flank modification. It is confirmed that the calculated minimum value of minimum principal stress and maximum value of maximum principal stress should be valid by comparison with tooth flank contact stress and tooth root bending stress calculated through ISO 6336.

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In order to obtain the high tooth surface strength, various kinds of methods were tested using case hardened spur gears. The test results show that the suitable tip relief or tip&root relief following the load on the gear tooth to obtain the high tooth surface strength is necessary. The hobbed gear have very good strength and case hardening in a vacuum also showed high tooth surface strength than the usual case hardened gears, but the differences of the effective case depth affect little on the tooth surface strength. The barrel polished after ground and MoS_2 coated on the ground gears showed very good tooth surface strength. The test results show that the gears obtained here have about twice as much as power transmitting ability than the ISO proposal.

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This research is to present a new method for fatigue crack length measurement using an ion sputtered film, the thickness of which is several tens nanometer, based on the principle that the electric resistance of the film increases with the growth of a crack. The relationship between the electric resistance and width of the film was investigated and expressed accurately by a presented equation. A grid pattern ion sputtered film was proposed for crack length measurement. Fatigue crack lengths in a bending test specimen are measured with a grid pattern film and a microscope. From the comparisons of the crack length measured by the film and microscope, a good agreement is verified and the availability of the presented method is confirmed. Since the film is extremely thin, it can be used for the measurement of a micro crack as well as crack initiation detection.

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In order to develop the case-carburized gears with the high load-carrying capacity, the changes in the rolling-sliding contact surface of the newly-manufactured Cr-Mo-Si steel were studied. First, the surface damage of test rollers was examined by using a scanning electron microscope. Secondly, the surface roughness, the surface hardness and the size of test rollers were measured with the use of surface roughness measuring instrument, hardness tester and digital micrometer. In the rolling-sliding contact surface of the Cr-Mo-Si steel that the fatigue tests were carried out, the following results are obtained: (1) It is possible to decrease the size of occasional micro pit. (2) It is possible to decrease the variation of surface roughness. (3) It is possible to decrease the variation of surface shape. (4) It is possible to decrease the variation of surface hardness with the high frictional temperature. (5) It is possible to decrease the variation of external diameter.

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In order to investigate the influence of shot peening on the surface durability of case-hardened steel gears, the case-hardened steel gears shot-peened with different shot velocity and shot diameter were fatigue tested using a power circulating type gear testing machine. The hardness, the compressive residual stress and the surface roughness of the gears increased by the shot peening. The failure mode of all the test gears was pitting. The surface durability of the gear shot-peened under medium condition in this experimental range was higher than that of non-peened gear, on the other hand those of lightly or strongly shot-peened gears were lower. Judging from the p_<max>-N curves and also the [A(δ_y/√<3> HV)]_<max>-N curves, it is proposed in this experimental range that the medium shot peening condition, that is, 60m/s shot velocity and 0.6mm shot diameter, should be selected in order to improve the surface durability of case-hardened steel gears.

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This paper presents a study on effects of carburized part, helix angle and face width on residual stresses of case-hardened helical gears. A heat conduction analysis and an elastic-plastic stress analysis during the case-hardening process of helical gears were carried out for various case-hardening conditions by the three-dimensional finite-element method (3D-FEM), and then residual stresses were obtained. The effects of the case depth, the carburized part (tooth surface, gear-side), the helix angle, the face width on the residual stress were determined.

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In recent times in the electric components' market, the development of a cylindrical micro coil has been long awaited. What is missing is an optimized injection molding machine to produce 3 dimensional micro-structures. Simply, conventional machines are too big in size and specification. To meet this requirement, developing a compact high-speed injection molding machine is essential. We proposes a new injection molding system for LIGA process with unscrewing mechanism, which includes peripherals and hybrid injection molding unit Utilizing this worm injection technology, a micro resin worm has been formed: liquid crystal polymer, diameter 0.5 mm, length 1.0 mm, worm profile 10μm and 20μm pitch. For this, the cylindrical micro coil has been successfully fabricated with metallizing process. Besides the its application as a conductance unit we expect this technology can be applied to develop a micro actuator in the future also. This breakthrough will create further possibilities of developing 3 dimensional micro components.

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LIGA process is one of the promising technologies for fabrication of extremely tall 3D microstructures with a large aspect ratio. Microstructures with height of over a few hundreds microns have been widely applied to various field such as micro-actuator, micro-mechanics, micro-sensor and so on. A key technology to realize a low cost in the LIGA process is the micro replication technology. Two kind of nickel molds,pole pattern having holes of a diameter 60μm, an aspect ratio of 1.0 beyond 65,000 in the are of 33×33mm^2, and hole pattern having columns which has the pattern dimension of the same as pole pattern mold. These were produced with X-ray lithography and nickel elect reforming process. In hot embossing in the atmosphere, an experiment of replication using PMMA succeeded.

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In order to enable precise microfabrication with a high aspect ratio, the new replication technique which combined hot embossing and ultrasonic vibration was suggested. In this method, it is the feature to add vertical ultrasonic vibration to a metallic mold and a resin sheet in holding process after applying load. Consequently, it is promoted that plastic flows into the precise pattern of a metallic mold, and the accuracy of transfer improves remarkably. We tested using a Ni mold with micro-pattern, and polycarbonate. It turned out that contacting force became low and holding time was also sharply shortened compared with a conventional hot embossing technique.

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We developed the new x-ray exposure system using synchrotron radiation (SR) at New SUBARU of laboratory of advanced science and technology for industry (LASTI), University of Hyogo. The new beamline consists from two-stacked beamlines with the different x-ray source energies; one is for the high energies (high energy beamline) from 3 to 15 keV and the another beamline is for the low energies (low energy beamline) from 100 eV to 3 keV. The apparatus has been designed for the fabrication of microstructures with the wider size range from submicron to milimeter at wider fabrication area of A4 size. In this paper the outline of the new LIGA x-ray lithography system and the quality of the fabricated microstructure are described.

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The Stephenson-3 six-link mechanism consists of the planar four-bar linkage and the external dyad. All relationships between the input and output angles are analyzed by solving the algebraic equation of sixth degree. The solutions are mutually contained in different branches or circuits. The branches are the parts of the coupler curves separated by two limit points. A circuit of a linkage is defined as all possible orientations of the links which can be realized without disconnecting any of the joints. In this paper, it is shown that these branches and circuits can be mapped on four number lines which are discriminated by the sign of the determinant of the Jacobian matrix and the sign of the sine of the relative angular displacement between two links of the external dyad. So the motion domains of the driving Link of the Stephenson-3 six-link mechanism are identified.

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The driving link of nongrashof planar four-link mechanisms, that none of two adjacent links can make a complete rotation, oscillates in such a manner that coupler and driven links take different forms of two link chain in going and returning respectively. A driving method of the nongrashof mechanism is presented, where two links to be revolute-paired the stationary link are driven by turns by four sets of sector gear trains to be rotated by one motor.

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CVJ lines of front drive automobiles are composed of the tripod constant velocity joint (CVJ) or the double offset CVJ, the Rzeppa CVJ and the drive shaft. The rotational angle error of the CVJ line and the whirling motion of the drive shaft (the tripod shaft) and its fluctuation of axial direction are analyzed experimentally. From results of experiments with several values of the angle a between the housing shaft of the tripod CVJ and the drive shaft and the angle β between the outer-race shaft of the Rzeppa CVJ and the drive shaft, characteristics of the rotational angle error and the three dimensional motion (the whirling motion and the fluctuation of axial direction) are made clear. The rotational angle error is sinusoidal of 2π/6 period. The whirling motion has the period of 2π or 2π/6 according to the angle β.

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The environment where Japanese industry has been paid with respect is changing tremendously due to the globalization of economics, where Asian countries are undergoing economical and technical development as well as advancing in information technology. With acceleration of manufacturing bases relocating abroad, industrial hollowing out is happening; hence effort to transfer the technology and the design knowledge of machine design in a company is becoming an important subject. For example, in the design of custom casting product, a designer who is lack of casting knowledge may not be able to produce a good design. In order to obtain a good design and manufacturing, it is necessary to equip the designer and manufacturer with a support system related to casting design or so called, knowledge transfer and creation system. This paper proposes a new computer-aided system for casting design, which is composed of the explicit and tacit knowledge transfer system using synchronised multimedia and the knowledge internalization system using portable virtual environment. This system indicates that our proposed method is useful as a knowlege transfer and creation method for casting design.

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Our laboratory is developing a power assisted suit system, which is actuated by several ultrasonic motors, the nursing care of bedridden people. The motion of this nursing care is such a complicated motion because we have to perform the motion so that it will not give any unnecessary load to them. This paper discusses how to design the mechanism which permits the complicated motion and develop the control method for the overall system. In order to expand the movement range of the suit's arm, we increased the number of the rotation axis. Furthermore, humans have to use specified several muscles to move one part of the body as defined by the functional anatomy system. To control this system, we propose a method that uses the skin surface electromyogram signals which can be detected from several muscles.

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The response of the human body is investigated in this paper, whishes receiving the forced torsional oscillation from the bottom of his foot at the stand up posture or the bottom of his hip at the sit down posture. An experimental apparatus to give a forced oscillatory motion is developed, and the responses of the human body for young and aged peoples are measured. The amplitudes and phase lags of the parts of the human body by the torsional oscillation of the body are measured. From these results, the data of natural frequency of the torsional human body and the resonance phenomena of the human body are obtained. The investigated physical characteristics will be used as the index for the degree of aging, the hardness and the softness of a human body.

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It is important for the aged persons or the handicapped persons to walk on their legs because of making recover their leg's function or having own volition to participant the society. Walk is a motion of the body center, which moves back and forward, up and down, and right and left, by bending and stretching the legs. Some walk training machines have developed until now using the mechanism to vibrate the floorboard up and down, however some problems occurred. Anew walk training machine with forkhft mechanism using vertical vibration of floorboard is proposed and developed. It is shown by measuring the paths of aged person's physical parts and the reaction force of floorboard that the new machine is useful to compare with the former machines.

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The purpose of this study is the development of simple and cheap rehabilitation device with a tactile sense presentation system for the grasping power disabled persons. The experimental apparatus in which is controlled by DC motor with a gear speed reducer, rotary encoder and torque sensor is developed. In this report, the output characteristics of the experimental apparatus are discussed.

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This paper proposes a manipulator system for Minimally Invasive Heart surgery. This manipulator system consists of three manipulators. First one is beat measuring manipulator which sticks on the surface of the heart and measures the position in 3DOF. Second one is Endoscopic manipulator which is synchronized with beat measuring manipulator. And third one is heart sheet sticking manipulator. By use of this manipulator system, surgeon is able to operate the heart as stationally object. Beat measuring manipulator consists of parallel linkage and flat surface linkage, and they are controlled passive and active by use of clutch engagement. Synchronization performance is evaluated by measurement of position error and latency.

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It was suggested that existence of compression delay influences a traction performance in high-pressure and high-shear condition. However measurement of volumetric viscosity has not been conducted in such condition. New dilatometry measurement with two plungers is developed for volumetric viscosity. By use of this dilatometry measurement volumetric viscosity under high-pressure (0.4-0.8GPa) is obtained. Variation of volumetric viscosity with pressure indicates the same tendency to that of shear viscosity. In the pressure range 0.4-0.8GPa compression delay exists and then influences the traction.

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An Equation to predict the pressure viscosity of lubricants was derived. It is a characteristic that this new equation includes cohesive energy density (CED) as a parameter of pressure dependence of lubricant viscosity. CED is calculated with the viscosity, density and molecular weight that the measurement is easy. This new equation can be applied to mineral oils, synthetic (paraffinic / naphthenic / aromatic) hydrocarbon type fluids, ester type fluids and ether type fluids.

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Traction grease is semisolid and produced by the dispersion of a thickener in traction oil. The traction coefficient of traction oil and grease are different especially in case of high peripheral speed or low temperature. The difference of film formation ability between them may cause the change of traction property. So the traction coefficient and film thickness are measured simultaneously in the range of temperature 253〜353 K, mean Hertzian pressure 0.39〜1.26 GPa peripheral speed 1.3〜5.2 m/s for traction oil and two kinds of traction greases whose consistency are different. Traction coefficient decreases in the range more than 0.5 μm. Using the measured traction coefficient of traction oil and the relation of film thickness difference between oil and grease. The estimated formula of traction coefficient for traction grease is derived. It is useful for more than 0.64 GPa in Hertzian pressure.

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Using a two-roller testing machine, the rolling contact fatigue life of bearing steel rollers with mirror-like smooth surfaces was examined. A pair of rollers were driven under the rolling with sliding condition of s=-3.2%, and a maximum Hertzian stress in the range of PH=3.0GPa〜4.0GPa was applied in point contact condition. As lubricant, a low viscosity synthetic traction oil with viscosity grade of ISO VG 32 was used, and the test results were compared with those obtained using a low viscosity mineral oil with almost the same viscosity grade. Consequently, the fatigue life with a low viscosity traction oil was shorter than that with a low viscosity mineral oil, and this tendency appeared more distinctly under higher stress conditions above PH=3.4GPa. Based on the numerical calculation results of the thermal EHL, the authors discuss the mechanism which causes such a difference in the fatigue life.

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The mixed and fluid film lubrication characteristics of hydrodynamic journal bearings with surface wear dents are examined numerically. The mixed lubrication model is applied to the analysis, which is combined with the asperity-contact mechanism proposed by Greenwood and Williamson and the average flow model by Patir and Cheng, considering the effects of adsorbed film. The impacts of the depth of the dents and the operating conditions on the loci of the journal center, the asperity-contact and hydrodynamic fluid pressures, friction and the flow rate are discussed. The conclusions are as follows: i) In the mixed lubrication regime the dent of the bearing influences noticeably the contact and fluid pressures; ii) For smaller dents the pressure in contact and the friction coefficient decrease; for larger dents the pressure and the coefficient increase, and iii) As the dent becomes deeper, the flow rate increases.

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Recent research into the tightening at the yielding point has brought to light the characteristics of this method and shown that it is both practical and effective. In this report, the tightening at the yielding point was carried out on screw of M10 by systematically changed snug torque to find out what effect the snug torque setting has on the tightening at the yielding point of screw. The main results of these tests are shown below. (1)When carrying out the tightening at the yielding point using the torque gradient control method, it is necessary to the select a suitable snug torque. In these experiments a range of 10〜60% was used. (2)Stable tightening is possible within a snug torque range in which a stop point can be clearly detected. (3)The torque coefficient in the tightening at the yielding point is slightly lower and more stable than in elastic region tightening.

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We have been developing a micro reducer with small, high accuracy and low cost. This micro reducer is composed of plastic plain bearings and mold plastic gears with shaft. One of the problems in this R & D gear system is how to reduce friction and wear between mold plastic plain bearings and mold plastic plain shafts or metal plain shafts. We tried to solve this problem by the combination of materials and lubricants. The much longer Operating life of a micro reducer is inquired. We developed the micro reducer much longer operating life. In this paper, effects of lubricating grooves on the plastic bearings are examined, and much longer life for the micro reducer is described.

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Recently, minutia ball-endmill has applied for micromachining. In this paper, we described wear characteristics of TiAlN, TiCN and DLC coated minutia ball-endmill with tip radius of 0.5mm, cutting condition and hardness of workpiece (SKD11 die steel) were changed. From the results, we found that Flank wear, depth of tip wear, wear area and wear volume of DLC coated minutia ball-endmill was higter than that of another. The rerationship between wear volume and maximum of flank wear has linear.

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Micro or nano-meter order silica process is an important technology for several industrial processes such as for semiconductor and for MEMS. The object of this investigation is to clarify the chemistry of silica process. Using Atomic Force Microscope (AFM), micro-tribological experiments were performed in alkaline solution and in pure water. The significant difference of wear mechanism between the two solutions has been obtained by comparison with their friction and wear characteristics.

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The alkyl-substituted phtlialocyanmes physisorbed on each substrate with their molecular planes parallel to the substrate surfaces. Therefore, we considered that these molecules used as one of the ideal models for monolayer lubricants. In this study, we attempt to clarify the relationship between the surface adsorbed structure and frictional properties. We focus on phthalocyanine derivatives as an example of lubricant molecules. Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) were used for the characterization of the adsorbed structure of molecules, and the friction force measurement, respectively. Considering the interaction between molecules and substrate, and the intermolecular interaction of phthalocyanine derivatives, we could explain the frictional properties depending on the alkyl-chain length of phthalocyanine derivatives.

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