Slider-crank mechanisms are frequently used to convert between linear and rotational motion. When a slider-crank mechanism creates linear piston motion, a side force occurs between the cylinder sides and the piston head. The side force can be reduced using a Scotch yoke mechanism. However a Scotch yoke mechanism requires two parallel opposed sliders, therefore it is difficult to keep a precision and structure complicated each machine elements. This side force causes various problems, so authors have proposed an orthogonal double- mechanism to reduce the side force acting on the piston. We build three types of water-pump to investigate efficiency differences among the driving mechanism types, namely, a slider-crank mechanism with a crosshead, a Scotch yoke mechanism, and the orthogonal double- mechanism. We measure the input torque needed to drive a water-pump under same conditions for stroke, cylinder cross-section, and crank rotational speed. To investigate the influence of sliding frictional resistance acting on the crosshead, we compare results between the cases of driving by the slider-crank mechanism with a crosshead and the orthogonal double- mechanism. To investigate the influence of structural differences, we compare results between the cases of driving by the Scotch yoke mechanism and the orthogonal double- mechanism. We find that among the three mechanisms the orthogonal double- mechanism can drive the water-pump with the least input torque.

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The number of people who are in need of nursing care due to difficulties they experience with performing various activities of daily living is increasing. In particular, the action of standing up is performed frequently in daily life, and this action starts to induce pain in joints as people age. In this research, we develop a device whose seat plate follows the movement of the thigh in the action of standing up for the purpose of relieving the burden from the joints and reducing the effort associated with nursing care. The device is designed by using a planar five-link mechanism and a gear train, and only a single input is needed to drive the device. The respective lengths of the links are determined by comparing the movement of the seat plate of the device with the movement of the human thigh in the action of standing up. In addition, this device is expected to be useful for assisting users in standing up in a natural manner, including in the case when the body remains supported by the seat plate, as well as for guiding the individual movements of users in the action of standing up.

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A slider-crank mechanism is important for the conversion between linear and rotational motion. When a slider-crank mechanism is making piston liner motion, the side force occurs between cylinder sides and a piston head. There are various problems caused by the side force. Therefore, the orthogonal double-

mechanism has been proposed in order to remove the side force acting on the piston in our research group. Authors built an experimental equipment to consider the effect of an arrangement of prismatic pairs upon the input torque in the case of driving a water pump. The experimental device is based on a Scotch yoke mechanism, input torques are compared between the cases of a single slider shaft and a parallel slider shafts arrangement. From the experimental result, an inference is derived, that is the moment occurred by the load of the piston head acting upon the slider shaft has effects on the input torque.

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A Scotch yoke mechanism is often used instead of a slider-crank mechanism to obtain high output power. The kinematics of the Scotch yoke mechanism are characterized by elements translating along two orthogonal axes. This is realized by two slider guides placed in parallel in each direction. As a result, the Scotch yoke mechanism achieves high power transmission with high rigidity. A drawback of this mechanism, however, is that it requires high precision in machining and assembly processes. In this study, an orthogonal double-slider mechanism was developed to solve problems caused by machining and assembly errors. With an L-shaped double slider, the mechanical structure is simple and this mechanism has the advantage of lower driving torque compared with a slider-crank mechanism. The developed mechanism is derived from a Scotch yoke mechanism, but the major difference between them is the arrangement of the sliders and slider guides. This study is the first to investigate the effect of the arrangements of slider guides on the driving characteristics of the mechanism. Through measurements of the force acting on slider guides and their deflection, the effect of the slider configuration was experimentally verified as the number of the slider guides was reduced from the maximum of four. In addition, when the mechanism was used in a water pump, the change in shear force acting on the slider guide in the direction of piston translation was investigated as the number of slider guides was reduced. The deflection of the slider guides for the piston was measured under static conditions. Also, the starting force from a stationary state was measured, revealing that the load acting on the mechanism was reduced by removing one of the slider guides arranged in parallel.

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The compressor can be classified a dynamic type and a positive displacement type. In the case of the high discharge pressure, the axial flow compressors are used without the pulsatory motion. While, the reciprocating compressors that one of the positive displacement type have the advantage of the higher discharge pressure. A slider-crank mechanism used in a reciprocating compressor is valuable to convert mutually between the linear and rotational motions. However, there is a problem about friction loss and the vibration caused by the force reacting on the piston from the cylinder side wall, during the piston stroke. This phenomenon shortens the lifetime of the compressor. The side force prevents the driving with the high velocity revolution, so a field of use is limited. When the reciprocating compressor can be driven with the high velocity revolution without the vibration and pulsatory motion, a new type of the compressor is realized to transport the air with high discharge pressure and the large volume. This type of compressor is expected to be applied to the field of manufacturing and welfare. In this paper, we try to design in order to eliminate the side force from the compressor, to realize the low vibration compressor using a orthogonal double- mechanism. We structured the kinematic model and verified the characteristics of the compressor experimentally.

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Slider-crank mechanisms are used as a rotational-to-linear motion transformer in positive displacement pumps, because such mechanisms are effective for generating high discharge pressure. The stroke of slider-crank mechanism in a water pump is twice the crank length and the connecting rod must be sufficiently long to avoid problems caused by the side force, thereby, limiting the extent to which a positive displacement pump can be miniaturized. Small pumps with high discharge pressure are expected to be used as the power source of a hydraulic actuator. In this study, a mechanism wherein eccentric cams replace a crank and a connecting rod is proposed, and the operating principle and characteristics of this mechanism are investigated. The mechanism has a stroke that is four times the crank length, and it is designed with reference to an Oldham coupling mechanism. Replacing a crank with an eccentric cam is expected to reduce vibration by reducing fluctuations in the position of the center of gravity, but a concern is that using an eccentric cam will cause friction loss. An experimental device is manufactured to investigate the driving torque and the vibration characteristics.

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This paper describes behavior of the jump robot which is connected by tether. The internal environment of the hole existing on the moon is not clear and is expected to be investigated. For research of the unknown environment, exploration is planned using a rover with umbilical tether connecting a mother rover near the hole. Then, it is important to study how tether influences jumping behavior of the rover. Equation of motion and differential algebraic equation is formulated by the use of Absolute Nodal Coordinate Formulation (ANCF) and multibody dynamics. Rover is regarded as two bodies with

. Telescopic motion of spring expresses effect of jump. Numerical analysis reveals the relation of jumping behavior and parameters, and is compared with experimental result.

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The compressor can be classified a dynamic type and a positive displacement type. In the case of the high discharge pressure, the axial flow compressors are used without the pulsatory motion. While, the reciprocating compressors that one of the positive displacement type have the advantage of the higher discharge pressure. A slider-crank mechanism used in a reciprocating compressor is valuable to convert mutually between the linear and rotational motions. However, there is a problem about friction loss and the vibration caused by the force reacting on the piston from the cylinder side wall, during the piston stroke. This phenomenon shortens the lifetime of the compressor. The side force prevents the driving with the high velocity revolution, so a field of use is limited. When the reciprocating compressor can be driven with the high velocity revolution without the vibration and pulsatory motion, a new type of the compressor is realized to transport the air with high discharge pressure and the large volume. This type of compressor is expected to be applied to the field of manufacturing and welfare. In this paper, we try to design in order to eliminate the side force from the compressor, to realize the low vibration compressor using a orthogonal double- mechanism. We structured the kinematic model and verified the characteristics of the compressor analytically.

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This paper presents an efficient method for generating complex motion of a human-like figure such as circus acrobatics including calculations for gravity and elasticity. The authors apply several motion dynamics techniques generated by using a motion generation engine. This allows iterative trial-and-error interaction to perform a wide range of acrobatic motion with a well designed user interface entailing the mouse, keyboard and joystick. Using this generator, some of the physical control parameters for the character such as gravity, rope angle, trampoline strength etc can be changed to affect the characters motion. We improved the dynamic motion algorithms for fester computation and we simplified the linked object structure and collision detection routines for a smoother operation during real-time interaction. As a results we can easily control the character's behavior on a variety of apparatus such as the trampoline, bungee swing, flying trapeze etc. This paper presents the methods we used to improve the motion generator using an interactive real time simulation. The methods used can be applied in the creation of games, movies and a broad repertoire of entertainment.

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XY 分離クランク機構は，著者等によって考案された新しい直線運動機構である。これはコネクティングロッドの揺動を無くし，ピストン変位を正弦波形にすることで，高次の振動が発生しない。著者らは，本機構をエンジン機構部に組み込み，機構とシリンダを鏡像的に配置することで，一次振動の解消と，機構自体の効果により二次，三次振動の極小化を実現し，極低振動・高速回転が可能な新構造エンジンを製作した。本報では，製作した XY 分離クランク機構鏡像配置二気筒エンジンの極低振動性について報告するとともに，ドローンへの応用可能性について述べる。

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The slider crank mechanism is used for conversion between linear motion and rotational motion, but the side force is problem to occur between cylinder sides and piston head. Theoretically, Scotch yoke mechanism can be mentioned as the side force does not occur. In this mechanism, slider guides are arranged in the vertical and horizontal directions, respectively. Also, in order to increase the rigidity of the mechanism, a structure is adopted in which two slider guides are arranged in the same linear movement direction. However, as there are many components and high assembling accuracy is required, it is rarely used in general. We thought that high assembly precision is required due to over constrain by using two sliders in the same linear movement direction. Therefore, in order to solve the above problem, the authors try to reduce each direction of slider guides of the scotch yoke mechanism. By reducing the number of slider guides in the dynamics experiment, the effect of changing the combination of slider guides is investigated using a water pump. Evaluation is done by comparing the input torque required to drive the mechanism and the load on the slider guide.

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In general rehabilitation, the walking stick, parallel bars, and walker are used as walking training devices. Users of these devices bear their weight with the hands or legs, and doing so is painful in some cases. In recent years, population aging has progressed rapidly and a labor shortage in the welfare field has become a serious problem. Against this background, it is necessary to develop a walking training device that can motivate patients to train without assistance from a care worker. In this research, we designed and developed a walker equipped with an assist mechanism that translates simulated walking motion into rotational wheel motion. Using the walker, the patient is supported by a saddle, so the hands and legs are relieved of pain due to supporting body weight. The motion transformer is designed using a planar 6-link mechanism, which transforms oscillating motion to rotational motion. Joint angular displacements were measured with a wearable device. Results showed that general walking trajectories can be obtained. This mechanism is designed such that the pedal follows the foot motion in walking by comparing the coupler curve of the mechanism with the trajectory of an ankle joint in a walking motion. We manufactured four types of walkers for testing. Type I uses a motion transformer consisting of only revolute pairs. Type II uses a motion transformer consisting of revolute pairs and a prismatic pair (sliding joint). Type II-ankle free uses a Type II motion transformer from which two links were removed in order to allow free rotational motion of the ankle joint. Lastly, the Type III walker has an axle in the front in order to facilitate riding from the rear and to allow free rotational motion of the ankle joint. Pedaling force was measured and compared among the four types. It was found that free ankle joint movement was effective in decreasing the pedaling force. The results indicate that the motion transformer could be driven with a small force and with a simulated walking motion as the input. However, the angle between the direction of foot velocity and the direction of pedaling force was approximately π/2, and so driving the device using a pedaling motion could produce a sensation different from that of a normal walking motion. Eliminating discomfort during operation is left as a future task.

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