摘要:
In a process for dehydrating 5-hydroxy-11a-chlorotetracycline-6,12-hemiketal to 5-hydroxy-6-demethyl-6-desoxy-6-methylene-11a-chlorotetracycline, utilizing an acid which is not decomposable by water, formic acid serves as a solvent free from chlorinated hydrocarbons.
摘要:
A device for the torque-transmissive securing of a disc which is formed of a brittle material, in particular a turbine wheel constituted of a ceramic material, onto a shaft. The disc is centered through the intermediary of two cone pairs with axial prestressing and the torque is transmitted to the shaft through a cylindrical extension of the wheel hub with longitudinal grooves formed on the outer circumference thereof; furthermore transmitted by means of a cylindrical bellshaped cover with symmetrically profiled longitudinal connectors in an inner bore which are conformed to the longitudinal grooves, and finally by rollers located between the concave side edges or slopes and the side walls of the longitudinal grooves in radial and tangential contact therewith, by means of the bell-shaped cover which is rigidly fixed on the shaft.
摘要:
An arrangement for connecting a ceramic rotor wheel, particularly a turbine rotor wheel of a turbomachine, such as a gas turbine, to a metallic shaft. In order to obtain a primarily temperature-resistant (ceramic wheel-to-metal shaft) connection suitable for high speeds, the arrangement includes a thermal insulation ring seated on the shaft journal of a ceramic rotor wheel, on which there is mounted the tubular end portion of the metallic machine shaft, and which is then positioned on the shaft journal for positive connection through the intermediary of at least one fiber ring which is press-fitted onto the end portion of the shaft.
摘要:
A high-temperature, extremely high-speed ceramet composite blade comprising a ceramic blade jacket seated from above on a metallic core having a crossweb near its upper end for securing the jacket on the core by one or more metallic retaining pins extending through the crossweb and secured to the core. A head on each bolt is located within a chamber formed above the cross-web and surrounded by the radially projecting end of the blade jacket. A porous abradable coating is secured to the head of the bolt and substantially fills the chamber. The coating projects slightly beyond the end of the blade jacket and is supplied and permeated with cooling air via a cooling duct extending through the retaining pin and metallic core.
摘要:
An ester base stock which comprises pentaerythritol, cyclohexyl carboxylic acid, isostearic acid and at least one other C.sub.6 -C.sub.16 saturated aliphatic monocarboxylic acid, having low volatility, a high flashpoint, and increased basic viscosity as well as a very high viscosity index.
摘要:
A chain wheel arrangement for chain drives of mining machines, with a chain wheel shaft, with a chain wheel, with bearing shells receiving bearings for the chain wheel shaft, with a chain wheel-side sliding ring seal and with a bearing-side sliding ring seal. In order to improve the service life of the chain wheel arrangement, at least one of the bearings, preferably that of the movable bearing system, is arranged in a bearing bush which is arranged between the bearing shell and outer bearing ring and received in the bearing shell in an axially displaceable manner. The additional bearing bush allows the necessary gap between the rotating parts and the non-co-rotating, bearing shell-side parts to remain substantially constant and to this extent to become independent of the bearing play of the respective bearings.
摘要:
The invention relates to a sprocket wheel for underground mining, especially for chain-driven chain scraper conveyors, with a first ring 2 of first tooth elements 5 distributed uniformly about the circumference of the sprocket wheel body 1, at least one second ring 3 or 4, disposed axially offset to the first ring 2, having further tooth elements 6 or 7, distributed uniformly about the circumference. The flanks of the tooth elements that face one another are provided with pockets 13, that serve as contact surfaces for the horizontal chain links 9. In order to increase the service life of the sprocket wheel, the contact surfaces in the pockets 13 of each tooth element 5, 6, 7 comprise a wear inlay 20 of wear-resistant material.
摘要:
Precombustion chamber construction in a cylinder head of a diesel engine utilizing ceramic material to increase resistance to thermal stresses. A space is provided between the precombustion chamber construction and the cylinder head at least at the main combustion chamber of the diesel engine, and one or more ceramic bodies are shielded from the metal cylinder head and any other metal by thermal insulation to minimize thermal stresses and enable combustion in the precombustion chamber to take place at a higher temperature whereby the power/weight ratio and the efficiency of the engine are improved. The precombustion chamber construction in one embodiment is composed of axially successive parts, and at least the part nearest the main combustion chamber is made of the ceramic material and shielded as indicated.
摘要:
In a method of manufacturing fiber-reinforced engine components having a metal matrix, a long or even continuous silicon carbide fiber is first coated with a matrix metal of a titanium-based alloy by atomizing or sputtering. Then, the fibers coated with matrix material are wound onto a mold in the direction of the anticipated stresses. A covering of foils, bands, wires, pressed-on granulates, sintered-on powders or a top coating of matrix metal is then applied onto the surface of the fibers wound onto the mold. Finally the mold with the wound-on, matrix-material coated fibers and the covering of matrix metal is subjected to hot isostatic pressing. This method is used to manufacture engine shafts, shroud bands for turbine wheels or disk-less turbine wheels having retaining rings holding the blades.
摘要:
A guide vane ring having guide vanes is provided on two rings which are arranged coaxially and radially at a distance from one another. These two rings are held on assigned housing sections which are subjected to thermally different expansions. One ring is rigidly connected with the guide vanes, and the other ring is connected with the free ends of the guide vanes by the compressive force of a tensioning element. In addition, the other ring is divided into several piston-ring-type elements which axially follow one another and which are each slotted approximately axially and form a cylindrical sliding surface for the whole free ends of the vanes. The tensioning element is arranged on the one group of assigned housing sections while forming a radial compressive force distributed uniformly on the elements.