Abstract: Provided are a ball-type speed reducer and a rotary table device that are capable of performing high-speed rotation and high-rigidity rotation and suitable for reduction in size and weight. An index table 10 includes a ball-type speed reducer 20 and a table 50 that is fixed to an upper surface of a worm wheel 30 of the ball-type speed reducer 20. When the worm gear 22 rotates as the input shaft 24 of the ball-type speed reducer 20 rotates, balls 36 made of a magnetic material move along a ball groove 26 having a spiral shape. The worm wheel 30 rotates as the balls 36 move, and the table 50 rotates. The balls 36 are attracted and held by the permanent magnet 34 on the worm wheel 30 side, so that a case for preventing the balls 36 from coming off the worm wheel 30 can be omitted, whereby the total size and weight can be reduced. Backlash is not required, so that high-speed rotation and high-rigidity rotation are possible.

Abstract: Provided are a ball-type speed reducer and a rotary table device that are capable of performing high-speed rotation and high-rigidity rotation and suitable for reduction in size and weight. An index table 10 includes a ball-type speed reducer 20 and a table 50 that is fixed to an upper surface of a worm wheel 30 of the ball-type speed reducer 20. When the worm gear 22 rotates as the input shaft 24 of the ball-type speed reducer 20 rotates, balls 36 made of a magnetic material move along a ball groove 26 having a spiral shape. The worm wheel 30 rotates as the balls 36 move, and the table 50 rotates. The balls 36 are attracted and held by the permanent magnet 34 on the worm wheel 30 side, so that a case for preventing the balls 36 from coming off the worm wheel 30 can be omitted, whereby the total size and weight can be reduced. Backlash is not required, so that high-speed rotation and high-rigidity rotation are possible.

Abstract: The present invention provides a molten carbonate type fuel cell comprising two electrodes as anode and cathode, an electrolyte plate and separators in a single unit and a battery of the unit cells stacked. The electrodes comprise a porous plate of an electron-conducting material such as nickel containing particles of ceramics such as magnesium oxide uniformly dispersed therein in an amount of 2 to 29 atomic %, except for the superficial thin portion free of the ceramic particles on the one-side surface of the plate. The electrodes are prepared by mixing a powder of the electro-conducting material with an organic binder under stirring to obtain a slurry or paste, deaerating the slurry or paste to remove entrained air bubbles therefrom, shaping the slurry or paste plate with or without a metal wire net, drying the electrode plate at room temperature and finally firing the plate in a reducing atmosphere.

Abstract: A molten carbonate fuel cell using molten carbonate as an electrolyte, carbonate ions as electric conductor, and feeding a hydrogen-enriched gas to the anode and a mixture of air and carbon dioxide gas to the cathode has its output fall by degrees with operation. It is surmised that one of the causes of this problem is ascribable to the fact that the molten carbonate electrolyte moves during operation to destroy equilibrium in the boundary between the electrolyte and electrodes. After studies for measures against the problem, the inventor found that the output of a fuel cell which has fallen can be improved by shutting off part or all of the raaction gases or reducing their feed for a while, and then restoring. The purpose of the present invention is to offer a high-performance stable-output molten carbonate fuel cell and its operation control method, incorporating the above findings in its operation control system.

Abstract: A unit cell is formed by a plurality of sub-unit cells as a result of dividing each of the electrodes and electrolytic plate into a plurality of parts. That is, the electrodes and the electrolytic plate are each divided into two parts by electrolytic plate support portions projected from the surfaces of separators. The support portions are pressed in contact with the end portions of the electrolytic plate so as to support the electrolytic plate and seal the reaction gas, preventing it from leaking. The electrolyte support portions of the separators can be provided with electrolyte supply paths, through which the electrolyte is supplied and impregnated into the electrolytic plate. The electrolyte can be supplied via the apertures provided in the separators, to the electrolyte supply paths.