This paper proposes whirl vibration control of winder by using a tuned mass damper (TMD). The winder has a cantilever type spindle that is supported at one end and free at the other. Due to the long length of the spindle, amplitude of vibration increases at critical speed. Because of winding up a synthetic fiber to the spindle, there is no space to mount the TMD to the outside of the spindle. For mounting to the inside of the free end of the spnidle, new TMD is proposed. The TMD is simply composed of a mass, a beam, and two spherical surface bearings, and it is possible to suppress whirl vibration of the spindle. The effectiveness of the TMD is confirmed by the experiment.

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One of the difficulties encountered in making a dynamical model of a real structure is to determine the boundary conditions. As a means to determine boundary conditions, many experimental identification techniques have been proposed. However, many of them require measurements of the responses at the boundaries, which is often difficult in practice. Also many are applicable only to linear boundary conditions, which is a restriction. As a basis for developing a technique free from measurements of the responses at the boundaries and applicable to nonlinear boundary conditions, one of the authors took up a beam and developed a new technique based on the analytical solution. In this paper, by introducing the finite element method, we generalize the technique so that it can be applied to any nonuniform beams. By a numerical simulation we confirm the applicability of the proposed technique.

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Numerical solution of Lagrange equation of motion for geometrically nonlinear rigid and flexible body dynamics has essentially a risk for numerical instability associated with time integration : There have been proposed several methods including energy momentum method that avoid this instability by enforcing the conservation of total energy and momentum.The energy momentum method provides a modification of the Lagrange equation of motion to ensure the solution satisfies the conservation unconditionally. However, there is few literatures that explain the detail on the relation between the original Lagrange equation and the modified equation of motion. This paper presents the straightforward derivation of the modified equation from the conservation principle of the energy and momentum. The general condition to formulate the energy momentum conservation algorithm in also shown in this derivation process. The results clarify the physical meanings of each term in the modified equation of motion.

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Oscillations around 1/2 order subharmonic resonance are investigated in a rotor system with a radial clearance between the bearing and the casing by numerical simulations and experiments. The following phenomena due to impact in the bearing are found : (1) Combination oscillations of [Pf -Pb=ω] and [3Pf-Pb=2ω] occur in lower speed range of + (1/2 ω resonance. (2) Entrainment phenomena occur in the speed range of + (1/2)ω resonance. (3) Oscillations of ω-Pf occur around the speed range of + (1/2)ω resonance with self-excited oscillation of Pf. Furthermore entrainment phenomena and coupling between self-excited oscillation of Pf and oscillation of ω-Pf are explained theoretically by a similar self-sxcited and forced oscillation model of nonlinear van der Pol's equation.

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In an upstream stage of steam turbine, a damper blade of gap control type, which can reduce vibratory stress by adjusting the gap between adjacent shrouds, is sometimes used. Although this type of damper blade is designed so as to reduce the vibratory stress by utilizing the collision of adjacent shrouds, it is probable that the vibratory stresses of a few blades increase due to mistiming effect. For the purpose of designing the reliable damper blade of gap control type, the mistuning effect should be considered at the design stage. In this paper, the analysis method for predicting the mistuning effect of damper blade of gap control type is presented and the response analysis of tuned and mistimed systems is carried out, in order to investigate the mistuning effect on the forced response as well as the vibration suppression effect due to gap.

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Active vibration control has been used in many mechanical systems to suppress unnecessary vibrations caused by unknown disturbance resources. In this paper, we consider the so-called simple adaptive control (SAC) method as a candidate of the vibration control method satisfying simple realizability and robustness of the controller. Though SAC itself is an adaptive tracking control technique, it can be recognized as an adaptive output feedback control from the stability viewpoint of the control system. To this end, we attempt to use acceleration sensor as a tool of measurement to realize practical control system. A design procedure of active vibration suppressing control system based on SAC with acceleration feedback is derived. A simple experimental result to explain the effectiveness of the proposed method is also given.

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Most of non-rubber type isolation systems apply frictional force. 0ne of the famous non-rubber type isolation systems is Friction Pendulum Bearing (:FPB) system. When using friction pendulum system in the open air circumstances, some have pointed out that long term durability of the systems must have been taken into account and it might have been very difficult to maintain the friction coefficient. In this study, the behavior of the structure and the isolation systems in considering the dispersion of the friction coefficient of the each device and vertical load on the each device is examined during earthquake. In this report, the analytical models used the existent isolated building and the square structure, and these models are considered as rigid body models. The dispersion of the friction coefficient and vertical load is made to occur from the normal random number. The behavior of the structure and the isolation systems during the earthquake was stochastically investigated using a Monte Carlo method.

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This paper describes the results of the response analysis and the experimental tests on the newly developed earthquake isolation system based on the theory of friction pendulum. In Japan, many types of earthquake isolation device or system have been developed and utilized to proted computers, predsion equipments and important works of art from the severe seismic attacks. Although the performance of isolation of the each every one of the systems is sufficient, cost of the system is considered generally higher than the user expected and the system requires enough surrounding space to obtain adequate isolation performance. When applying the isolation device to the objects such as display cabinets in museum, computer server racks, bookshelves in library and vending machines which are generally placed adjacent to the wall, it is desirable to set them as closer to the behind wall as possible without decreasing their performance of isolation very much. The friction pendulum type isolation device with poly-curvature has been developed to satisfy these requirements, and the response analysis and the shake table tests have been carried out to investigate the performance of the system.

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In the case of a very large test specimen or the test specimen with very strong nonlinearities, it is impossible to perform the seismic excitation tests using even a very large shaking table such as one at Tadotsu. 0ne of the ideas to solve these problems is to install only the main structures and the actuator system on the shaking table and to remove the subsidiary structures. This actuator system is so called "Multiple excitation simulator", which should give the seismic motions equivalent to the removed subsidiary structures to the main structures. The authors have developed a "Multiple excitation simulator" system based on the uni-axial displacement control system, and confirmed the applicability through the various experiments. This report summarizes these experimental data and discussed the effectiveness of this system.

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This paper describes synchronization and phase difference control of two vibratory systems in elliptical vibration machine. Each vibratory system has local feedback loop for generating selfexcited vibration. The driving by self-excited vibration follows the resonance frequency change automatically and it reduces energy consumption. Natural frequencies differ in each vibration system, and then the frequency of self-excited vibration also differs. Therefore elliptical waveform changes incessantly. To synchronize each vibration, the control system has the feedback loop of the mean of velocity in two vibratory systems. It causes entrainment phenomenon in the same frequency. And large gain in the synchronization control, reduces phase difference between two vibratory systems. Phase difference control by phase shift filter gives constant phase difference between horizontal vibration and vertical vibration. Synchronization control and phase difference control of elliptical vibration machine stabilizes elliptical wave, which is generated in natural frequency.

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The ER (electro-rheological) fluid is a substance that can change its apparent viscosity by applying an electric field. There are so many researches about ER fluids that are based on parallel electrodes between which ER fluids are filled. In the previous paper, we have proposed one-sided pattern electrodes that have some advantages. Then, we have shown the ER effects of a homogeneous ER fluid on the proposed pattern electrodes experimentally. ln this paper, we consider four kinds of configurations of electrodes and electric potential, and analyze the electric fields. The relationship between the configurations and viscosity is discussed. Also, the ER effect of a different kind of homogeneous ER fluid on the one-sided electrodes is investigated.

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The ER (electro-rheological) fluid is a substance that can change its apparent viscosity by applying an electric field. We have proposed one-sided pattern electrodes that have some advantages. Then, we have shown the ER effects of a homogeneous ER fluid on the proposed pattern electrodes experimentally. In this paper, we consider a calculation method for the viscosity by using FEM. The relationship between the configurations and viscosity in investigated.

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In previous papers, the authors proposed two types of passive dampers using a lever-type displacement magnifying mechanism. One is a magnetic damper using rare-earth magnets and the other is a viscoelastic-friction damper using acrvlic viscoelastic material. In this paper, a new type of hybrid damper using a lever-type displacement magnifying mechanism, giant magnetostrictive actuators and rare-earth magnets is proposed. The hybrid damper generates controllable friction force together with magnetic damping force which acts as a fail-safe mechanism in case of control system trouble, and is suitable for vibration in the region of amplitude 0.1∼10 mm. The trial damper was made and the resisting force characteristics were measured. The seismic responses of a three-dimensional piping system supported by the damper were measured using an electrohydraulic type shaking table. The experimental results are compared with the calculated results obtained by the finite element method (ANSYS), and the effects of vibration suppression of the hybrid damper are discussed. Moreover, these experimental and calculated results are compared with those obtained for a semiactive friction damper (which is one removed the rare-earth magnets from the hybrid damper) and a passive magnetic damper (which is one removed the giant magnetostrictive actuators from the hybrid damper).

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The first paper by authors presented an optimal design method for vibration reduction using additional scalar spring elements. As an advanced work of the previous one, this paper deals with a coupled acoustic-structural system using additional beam elements. First, an analytical sensitivity of the sound pressure level is formulated transforming the dynamic mass matrix of the coupled system into the symmetric matrix. A new-coupled reduction method is also presented based on frequency response functions. Then, an analytical sensitivity with respect to a cross-sectional property of an additional beam element is formulated without using an inverse matrix of the dynamic mass matrix. And, an optimization problem, where the sound pressure level at a target frequency domain as an objective function is formulated and then the methods for sensitivity analysis and optimization are shown with respect to, additional beam elements, is formulated. Finally, we demonstrate the effectiveness of the proposed method through the simple numerical example.

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Using cluster control, this paper presents active noise control of structure-borne sound radiating from a vibrating rectangular plate. Cluster control consisting of both cluster filtering and cluster actuation enables the suppression of a target cluster without causing a spillover of any clusters. It is the purpose of this paper to apply the cluster control to a conventional active noise control, thereby permitting one to independently suppress the noise grouped into a finite number of clusters. ln the latest research, it is shown that when a rectangular plate is targeted, acoustic cluster filtering can be realized using just 4 microphones. This paper, then, presents a method of acoustic cluster actuation, a counterpart of the acoustic cluster filtering, that may activate only the target cluster, and hence its capability is verified mathematically and experimentally. Moreover, by applying the cluster control to active noise control, a novel clustered-active noise control is proposed, the fundamental properties being clarified. Finally, experimental results targeting a rectangular plate are shown, demonstrating the validity of the clustered-active noise control for suppressing structure-borne sound.

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The purpose of this study is to measure sound transmission loss of sound insulation materials practically with small size samples. When transmission loss of sound insulation material is measured with small size sample, it contains effect of panel size. Some studies about that effect have been done, experimentally or analytically. But, that effect has not been revealed clearly yet. This paper describes the results that transmission loss of rectangular panel simply supported in an infinite baffle was calculated. First, we investigate the effects of sample size on sound transmission loss, in two factors of nonresonance transmission (forced vibration transmission) and resonance transmission, then determine sample size not to affect transmission loss below critical frequency. Second, we compare the calculated results and the experimental results.

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It is essential for robotic tactile sensors to provide capability of shape discrimination from static touch. For this purpose, the principal curvatures and corresponding principal directions play important roles which define the local shape of the object. This paper proposes a novel acoustic tactile sensing system which identifies a set of principal curvatures and directions on the object surface by utilizing acoustic waves. The major difficulty, however, existing in estimating these parameters is that the wavefront reflected by the paraboloidal surface cannot be described in the linear combination of the plane-waves, such that the non-linearity exists between time-of-fright (TOF) and the parameters defining the surface. Avoiding the difficulties, the proposed sensing system utilizes the differences of TOFs between primary and secondary reflections.

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We have developed the 3D shape evaluation support system which integrates the visual and gazing line-motion information in virtual space and tactile information in real space, for the analysis of 3D shape evaluation in virtual space by synthesis. ln this paper, the influence of visual information with time delay on 3D shape evaluation in virtual space is investigated by using the proposed system. The sensory evaluation by paired comparison of 3D shapes and the questionnaire are carried out with time delay and without time delay in virtual space and in real space. The result shows that the visual information with time delay affects the shape evaluation in virtual space, especially the evaluation of subtle shapes.

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The purpose of this study is to develop a precise angular position control system of the hydraulic motor with undesirable dead zone using a Neural Network. In the previous works, we showed that the state feedback Neural Network control has a good effect on improving position control accuracy and robustness, and then, it was confirmed that the application of the PWM signal to the Neural Network position control system attains a very small angular positioning. 0n the other hand, it is well known that one method for eliminating the dead zone characteristics is to superimpose the dither signal into the input current of the servovalve. ln this study, the effective method using a dither signal together with the on-line training of the Neural Network is proposed in order to achieve precise positioning performance. Amplitude and frequency of the dither signal are examined by analyzing a linearized model of the hydraulic motor load system. From the computer simulation and experiments, it is recognized that the dither effect improve the steady performance of Neural Network based position control system.

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This paper proposes a self-organizing control strategy of a signal network for urban traffic flows. The signal network is described using a system of nonlinear oscillators with the nearest neighborhood coupling. Natural frequency, split and coupling constants of the signals are adjusted dynamically according to local information of traffic flows so that the desired network offset patterns are self-organized through mutual synchronization. We provide preliminary analysis of the coupled oscillator system. Numerical simulations demonstrate the effectiveness of the proposed method under dynamical environmental changes.

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In order for a robot to manipulate a flexible beam object, methods of establishing a deformation model of the beam object and analysis of the contact force detected by a force/torque sensor have been widely introduced. However, those methods can not be applied when the physical properties of the beam object are unknown. In this paper, sensor fusion of visual and force/torque information using on-line learning neural networks is proposed. The proposed method is applied to a 6 DOF robot to perform a beam-in-hole task. To detect deformation of the beam object, two CCD cameras are used and real time image processing has been developed. Visual information obtained from the two CCD cameras and force/torque information obtained from a force/torque sensor are integrated by three multi-layer neural networks. The outputs of the neural networks are connected to a proposed controller to generate the desired velocity of the robot. Experiments using different beam objects have been made successfully demonstrating the effectiveness of the proposed method.

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A smart structure is composed of the piezoelectric film sensor and actuator in order to reduce the structural vibration. H₂ controller is designed with the reduced order model of the smart structure which is obtained by finite element and modal analyses. The control force is applied by the piezoelectric film actuator and the feedback signals are detected by the piezoelectric film sensor and the accelerometer in the system. The vibration response is suppressed by the modal control and the displacement control in which the modal coordinate displacement and the spatial displacement are taken as the controlled variable. The shapes of the multiple piezoelectric actuators and the H₂ control system are simultaneously optimized to achieve an enhanced vibration control performance. Efficient optimization algorithm based on a two-step procedure is employed in the simultaneous optimization. It is verified that an enhanced performance on vibration suppression can be achieved by the presented optimal design.

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PLZT element has a characteristic that mechanical strain is occurred by photostrictive effect when exposed to ultraviolet light. The photostrictive effect is multiple effect of photovoltaic effect and piezoelectric effect. Up to now optical actuators that make use the photostrictive effect have been studied. But, its displacement is not so large. Therefore, this paper proposes an electrostatic optical motor driven by optical energy. lt is a new type of actuator that makes use of the photovoltaic effect and electrostatic force. The high voltage generated by photovoltaic effect when exposed to ultraviolet light causes electrostatic force. And, the electrostatic force drives the electrostatic optical motor. This new type motor has some superior characteristics such as non-contact energy supply, large rotational motion and the like. A driving mechanism of the electrostatic optical motor is described, and a result of a fundamental experiment for verifying the driving mechanism is discussed.

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Visual servo system is a robotic servo mechanism that incorporates the vision sensor in the feedback loop. However, it is difficult to measure object's positions of real time using vision sensors. Moreover, the other sensors can't make an accurate estimate the object's positions. Because position is calculated by measured velocity using other sensors, the estimating error accumulates with time. For example, the other sensors are gyroscope sensor, accelerometer and so on. We make the robotic mechanism that incorporates other sensors and vision sensor in a feedback loop. ln this study, we propose a reduction method of accumulation error using visual sensor. The estimating value is undated every few sampling period by the image processing of captured image. The process is used Hough transform. The present visual servo system makes partially delayed feedback system in terms of the estimating value. Finally, the experimental results are provided and the usefulness of this technique is confirmed.

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This paper considers the problem to design force controller for a two-link robot manipulator with contact motion to environments. Generally, the environmental characteristics that the manipulator is in contact with are not often known, and some of them have nonlinearity. Therefore we assume the environmental characteristic which is identified in real time as the spring element, and make the it scheduling variable. We propose a new type of sliding mode controller with gain-scheduled swiching hyperplane. By using this controller, hyperplane can be changed for various environments and adapted to nonlinearity of the environmental characteristic.

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Parallel loop simulation realizes accurate simulation results of direct yaw moment control (DYC) in tire critical range, by using simple model of tire and vehicle. This simulation method has two special features ; one is adapting parallel loop simulation including vehicle models with each loops, and the other is using measured data of vehicle behavior as input data. These techniques refuse circulation of the integrated value of tire force error therefore extremely accurate simulation results are obtained.

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This paper evaluates the effectiveness of four-wheel-steering systems from the viewpoint of lane-keeping control theory. ln this paper, the lane-keeping control system is designed on the basis of the four-wheel-steering automobile whose desired steering response is realized with the application of model matching control. Using simplified linear 2 degree-of-freedom bicycle model, Simulation study and theoretical analysis are conducted to evaluate the lane-keeping control performance of active four-wheel-steering automobiles which have different desired steering response. Finally, the evaluation is conducted on straight and curved roadway tracking maneuvers.

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In this paper, sloshing in a cylindrical container caused by a curved path transfer is represented by a spherical pendulum model. The model is used to design the curved path and the cart control system considering the damping of sloshing in the liquid container transfer. Radii of curved path are designed by a preshaping method, and a two-degree-of-freedom control system is applied to control the position and the speed of the container on the cart. The two-degree-of-freedom control system is constructed of feed-forward and feedback parts. The feed-forward control input is derived from the preshaping method, and the feedback part is constructed from a LQ controller and Kalman filter. The effectiveness of the present method has been clarified through experimental and simulation results.

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This study analyzes the mechanism how structural flexibility gives the effect on weave mode using the two-wheeled vehicle model considering structural flexibility. In general, the effects of structural flexibility on weave mode depend on the traveling speed of vehicle. At high speed condition, lateral bending flexibility of front fork and torsional flexibility of rear swing arm give more significant effect on weave mode. These are mainly due to change of the external force by yaw rate in lateral motion freedom. The consideration of lateral bending of front fork advances the phase of the external force by yaw rate in lateral motion. 0n the other hand, the phase is delayed in the case of torsion of rear swing arm. The phase change of the external force by yaw rate in lateral motion affects the stability of lateral motion, and it affects the stability of weave mode as the result.

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We have developed a thyratron-gated, white nanosecond pulsed light source for high-speed stroboscopic measurement using a commercially available Xe shorr-arc lamp. To reduce time jitter, a grounded grid thyratron and an avalanche transistor are used for this light source. The grounded grid thyratron plays the role as switching component for high voltage and large current, and the avalanche transistor plays the role as main parts of fast trigger pulse generator. Time jitter was determined quantitatively using time to amplitude converter (TAC). The minimum value and maximum value of time jitter were 1.44 ns (FWHM : full width at half-maximum) and 4.5 ns (FWHM), respectively. As time jitter of the previous pulsed light source using grounded cathode thyratron was 8 ns, sufficient results were obtained. Intense light pulses as large as 85 W (peak value) of 15.3 ns duration (FWHM) was obtained from the proposed Xe lamp system. The reduction of the time jitter is suitable for an excitation light source in time-resolved spectroscopy and also for a stroboscopic illumination in a high-speed fluid experiment.

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MQL is applied to the helical feed milling hole-making process of aluminum alloy. lt is difficult to drill on aluminum alloy without cutting fluid because the adhesion to the tool leads to a chip jam, the tool breakage or low accuracy. By employing the helical feed milling, cutting temperature will decrease, each chip length will become short and a chip jam in a hole will be avoided, because the intermittent cutting is realized. As a result of employing the helical feed milling with MQL, it was shown that the shape error is decreased, a burr formation is decreased, machining temperature becomes low and the cutting force becomes small comparing with drilling process. Shape error by helical feed milling with MQL is comparable with that with flood coolant. In this case, small mist particle counts under 5μm, which affects working environment, are almost constant if the spindle speed varies. Scattered mist particle counts are less when MQL is employed over 20000 min^-1 spindle speed comparing with the flood coolant.

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This paper clarifies the geometric generating mechanism of chip and machined surface in consideration of the tool orientation in ball-nosed end milling. Firstly the cutting cross section area A_g is proposed as the index of cutting state. lt is one when the cutting edge generates the designed surface in the bottom. lt changes according to the tool orientation, and affects the machining accuracy. Secondly the characteristic related with the tool orientation in several machining, for example contour cutting and scanning cutting, has been clarified. Thirdly there are pointed out the geometric difference of cutting mechanism between ball-nosed end milling and the other end milling.

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The study deals with a deburring and finishing tool path generation method for robots, based on the process planning information. Although CAM systems, which are useful for robot teaching task and process simulation, have been developed and spread to various applications such as spot/arc welding, spray painting and so on, but they have not been necessarily used in cast deburring fields. It is due to three major issues concerning the specialty of deburring and finishing tooling conditions. The first is lack of CAM system to apply diverse shaped and sized tools and to generate their paths for a variety of workpiece shapes to be deburred and finished. The second is the difficulty of setting working points, taking account of tool life and production cost. The third is the necessity of solving the interference problem between workpiece and tool. The study analyzes the information necessary for tool path generation using diverse tools applied in accordance with workpiece shape and burr occurrence conditions. Then we propose a generalized tool arrangement method for generating tool path, which settles three issues : applying diverse tools, improving tool life, and avoiding interference, by parametrically defining working points and coordinates on tools and on workpieces. As a result, it is experimentally proven that the system is effective to deburr and finish cast workpieces.

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Loose-abrasive machining with ceria, zirconia or iron oxide slurry is traditionally employed for finishing optical glass. The machining process, however, has problems involving inefficiency and a detrimental impact on environment. Therefore, it is strongly recommended that the process be replaced with fixed-abrasive machining, but conventional fixed-abrasive tools have problems relating to low finishing efficiency or low finished surface quality. In this study, a lapping film utilizing agglomerative fine abrasives is introduced for finishing optical glass to overcome the above problems. The finishing experiments revealed that the good surface quality was comparable to that obtained by polishing with ceria slurry and the finishing efficiency was much higher. Furthermore, it was found that in the process of finishing, agglomerative abrasives were worn flat uniformly and gradually, that is, the self-dressing action of agglomerative abrasive occurred continuously.

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The thermosetting resin has been used as the bonding agent to produce traditional dicing blades. lt takes usually several hours for curing process and requires lapping process to true the blade shape. These are the causes of high manufacturing costs. In general, the use of ultra-violet curable resin as the bonding agent can greatly reduce manufacturing costs by reducing the curing time from hours to minutes. Dicing blades with ultra-violet curable resin have been developed to solve such problems. We proposed and developed a new producing method to obtain ultra thin dicing blades with ultra-violet curable resin. lt is called the spin-coating process using centrifugal force that drives deposited resin flow radically outward on the disk. And in order to improve the mechanical characteristics of the blades, some kinds of abrasive grains and fibers as the filler were mixed with resin. With those blades we have carried out the cutting tests on silicon wafers. As the result, in comparison with the existing thermosetting resin blade, the mechanical characteristics and the chipping distributions have been improved.

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The friction loss of spur gears has been studied for a long time, but it has not yet been made clear. In this study, we carried out the experiments to obtain the influence of Rear ratios and center distances on the friction loss of spur gears, using power circulating test equipments. The gear ratios used in these tests were i≒1∼4 and three kinds of center distances were used, that were a=48, 91.5 and 183 mm. Test results showed that the friction loss of gear ratio i=1 is the lowest among other gear ratios if the center distance is constant and the pitch line velocity is the same and also showed the longer the center distance, the lower the friction loss. We showed the mean coefficient of friction in experimental equation concerning with the mean sliding velocity and Hertzian pressure.

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Since the manufacturing methods of gears were improved, the failure of case-carburized gears has changed to the surface fatigue of the tooth flank from the fatigue breakage at the tooth fillet. The objective of this work is to develop the case-carburized gears for the high load-carrying capacity. Then, the factors of influence on the surface durability of the hypoxia vacuum melting case-carburized alloy steel were investigated by using a backup-roller-type two-roller fatigue test rig. As a result of examining the rolling-sliding contact surface of the test roller under the high load condition. the following were clarified :(1)The surface failure with various features occurs. (2) The surface temperature rises above tempering temperature of heat treatment process. (3) The surface asperities become very smooth. (4) The surface profiles are greatly deformed. (5) The surface hardness decreases. In addition, (6) The outside diameter of the test roller increases.

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Mixed and fluid film lubrication characteristics of hydrostatic spherical bearings for hydraulic piston pumps and motors are studied theoretically under unsteady state conditions. The basic equations considering interference and contact of surface roughness are developed using the mixed lubrication model based on the GW and PC models. The effects of the operating conditions and the bearing dimension on the motion of the sphere, asperity-contact/fluid pressure distributions, leakage flow rate, power loss and the stiffness are examined. A seat geometry which reduces the asperity-contact pressure is presented. A simplified model applicable to the limited conditions in the fluid film lubrication is also derived.

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Dynamic characteristics of an oil-lubricated spiral grooved journal bearing are investigated theoretically in this paper with considering the effect of cavitation occurrence in the bearing clearance. The equivalent flow model is applied to Reynolds equation expressed by the boundary-fitted coordinate system. The Reynolds equation is expanded by perturbation scheme with respect to the journal eccentricity, so that the dynamic bearing characteristics such as bearing stiffnesses and damping coefficients are calculated from the obtained results of perturbed pressure distributions. It is shown that, when the cavitation occurrence is taken into account, the value of the direct bearing stiffness becomes larger, while those of the cross-coupling bearing stiffness and damping coefficients become smaller, compared with those without considering the contribution of the cavitation occurrence. The effect of whirling velocity of the rotor to the bearing characteristics are also investigated, and the dynamic bearing characteristics are shown to be remarkably affected by the rotor whirling motion when the whirling velocity exceeds about half of rotational velocity of rotor. S table operating limits against "Half-Frequency Whirl" are discussed as well, showing that the critical mass values become larger when considering the cavitation occurrence than those without considering it.

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In this paper, a manufacturing feature recognition method for the generation of multiple process plans is proposed. The feature recognition method is constructed in 2 phases. First, features are extracted using Extended Super Relation Graph (Extended SRG) Method. By using Extended SRG Method, interacting and overlapping features can be extracted in several different ways, corresponding with different kind of machining operations. ln the second phase, we organize the extracted features into manufacturing feature sets using Feature Spatial Relation (FSR) Method. By organizing features into multiple manufacturing feature sets, the generation of multiple process plans is made possible, since each manufacturing feature set corresponds with different kind of process plans. In this paper, we describe the Extended SRG Method and FSR Method. We use a case study to clarify the effectiveness of these methods for the manufacturing feature sets creation.

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