Abstract: A redundant closed loop control circuit has a plurality of channels, one of which is the presently active or operating channel, while the other channel (or channels) is in a standby state. When the active channel fails, the standby channel is automatically switched on. The switch-over takes place with a certain time delay determined by a time constant. For this purpose each channel has an analog integrator connected with its input to a change-over switch and with its output to a negative input of its own signal summing circuit having at least one positive input connected to the output of the other integrator of the control circuit. The integrator of the active channel receives an input signal through its change-over switch and is disconneced from the output of its own summing circuit.

Abstract: A radial compressor rotor, especially for static imbalance of a dual flow radial compressor impeller, having back-to-back blades in a gas turbine engine, is provided with at least one axial through hole in the rotor hub. The axial hole is filled in by an imbalance compensating insert which covers the ends of the hole between neighboring radial blade contour surfaces in an aerodynamically flush manner. The density and density distribution of the material of the insert is selected relative to the density and mass concentration of the material of the compressor impeller to achieve the desired imbalance compensating effect.

Abstract: A metal structure component is provided with a protective coating including three layers. A first layer on the surface of the metal structural component is a bond improving metallic base layer on which an intermediate heat insulating oxidic layer is applied, followed by a titanium fire inhibiting metallic cover layer. Due to this arrangement of three layers, it is possible for the advantageous characteristics of the individual layers to cooperate to provide a good bonding and heat insulating protection of the intermediate layer in combination with the titanium fire inhibiting protection of the outer layer, whereby the structural component achieves a prolonged operational life without a substantial weight increase as compared to conventional protection layers provided only for heat insulation purposes. This layer structure also minimizes any adverse influence on the structural strength of the metal structural component.

Abstract: A structural component of titanium or titanium alloy is provided with a protective coating made substantially of an oxidation resistant and diffusion inhibiting base layer (2), an intermediate layer (3) forming a titanium fire inhibiting layer, and a cover layer (4) forming a passivating sealing layer. These layers are applied by various methods.

Abstract: A turboramjet engine is provided having a ram air duct which is constructed between an outer duct wall and a housing-type shrouding of a basic turbo-engine, and having shut-off devices by means of which the ram air duct, when the basic engine is switched on and the ramjet engine is switched off, is to be shut-off on the air supply side, with the simultaneous release of intake air into the basic engine. In this case, among other things, the shrouding is to form an air shaft which is widened in a polygonal manner in the direction of the inlet-side end of the ram air duct and is to have breakthroughs there, the shut-off devices being flaps which are pivotally arranged at the breakthroughs and which, when the ramjet engine is switched on, expose the breakthroughs and in the process form a shut-off body of the air shaft which is symmetrically acutely folded together with respect to the ram air flow.

Abstract: A gas turbine engine is disclosed having a mixed-flow compressor and a connecting mixed-flow diffuser. The mixed-flow diffuser is disposed inside the annularly arranged combustion chambers and supplying them, from the direction of the radial interior side, in the reverse flow, with compressor air. Gas turbine engines of this type are more compact and show a higher efficiency than turbine engines having radial flow compressors.

Abstract: A seal for sealing the space between a rotor and stator of an axial flow machine is disclosed which includes axially spaced sealing points. Between the sealing points auxiliary blades are provided for inducing turbulence to assist in improving the seal between pressure spaces located upstream and downstream of the sealing points.

Abstract: A structural component of metal is protected against titanium fires that can be caused by flying and burning titanium droplets, e.g. in a propulsion unit. The protection against titanium fires of metal structural components is provided by a surface coating made of ceramic fibers embedded in a matrix material of a high temperature lacquer having dispersed therein aluminum powder as a filler material. The high temperature resistant lacquer is formed of silicates as a vehicle in which the aluminum powder is dispersed.

Abstract: A method for producing a galvanically deposited protection layer against hot gas corrosion of a structural component, involves immersing the structural component in an electrolytic bath of a cobalt and/or nickel matrix material. Alloying chromium and/or aluminum particles are suspended in the electrolytic bath. Gas bubbles are mixed into the electrolytic bath, and the immersed structural component is rotated in the bath while the galvanic deposition or coating takes place. The bath is stationary and rotation of the structural component takes place about a substantially horizontal axis.

Abstract: A fiber composite material has individual reinforcing fibers embedded in a bonding matrix material. The bonding of the fibers to the embedding matrix material is controlled along the length of the fibers by axially spaced fiber surface bonding zones having a high bonding ability and alternating with further fiber surface low bonding or non-bonding zones having a low or no bonding ability relative to the matrix material. The bonding zones having a high or maximal bonding ability are distributed optimally as to size, location and spacing along the length of a fiber so that loads or forces including the breaking load are transmitted from one bonding zone to the next bonding zone which are preferably formed as ring zones. The low-bonding or non-bonding zones are so dimensioned that bonding zones of fibers located adjacent to one another do not overlap in a direction across the length of the fibers.

Abstract: Structural components of at least one intermetallc compound and having complicated contours, are made by the steps of preparing a powder mixture of elemental metal powders including at least one powder of a low melting metal element or component and one powder of a high melting metal element or component that subsequently are to form the intermetallic compound. The powder mixture is then sintered to form a sintered body which is machined to a contour close to the finished contour and to dimensions close to the final dimensions. The so machined and shaped part is enveloped with an envelope of the high melting metal element or component. The enveloped part is subjected to a hot isostatic reaction pressing whereby the intermetallic compound is formed.

Abstract: Diesel engine exhaust gas is cleaned by burning soot to convert the soot into gas. For this purpose the exhaust gas from the diesel engine is caused to travel through a helical or spiral channel, whereby centrifugal force causes soot particles to collect on radially outer, inner circumferential channel surfaces, where the collected soot is combusted by heating elements reaching into these channels, preferably into channel pockets.

Abstract: A structural component of titanium or titanium alloy is provided with a protective coating made substantially of an oxidation resistant and diffusion inhibiting base layer (2), an intermediate layer (3) forming a titanium fire inhibiting layer, and a cover layer (4) forming a passivating sealing layer. These layers are applied by various methods.

Abstract: An arrangement is disclosed for the sealing-off of spaces acted upon by media of a different pressure, for turbomachines, in which a sealing ring is arranged in a cylindrical housing while forming a radial sealing gap as a primary seal, and having a secondary leakage flow passage between a wall section of the housing and the sealing ring which communicates with the space having a lower pressure, the sealing ring being centered by means of spring elements which are anchored at the housing on one side and are arranged essentially in parallel with respect to the machine axis.

Abstract: A foil intermediate layer is arranged between machine parts forming a joint to protect the machine parts against fretting corrosion. The foil intermediate layer includes at least two foils or plies of which the respective inner contact surfaces contacting each other, have a lower coefficeint of friction and a higher resistance to wear and abrasion, than the respective outer surfaces of the foils or plies contacting the joint forming surfaces of the machine parts. Thus, relative motion between the machine parts forming the joint under oscillating loads or vibrations, is transmitted to the easily gliding wear resistant contact surfaces of the plies so that the machine parts are protected from fretting corrosion, whereby their operating lifetime is increased.

Abstract: An electrical conductor or cable splice is formed by passing the conductor ends from which any insulation has been removed through a ceramic insert so that portions of the conductor ends protrude out of the ceramic insert. These protruding portions are then mechanically and electrically connected to each other, by example, by soldering, welding, or brazing. A metal sleeve is then pushed over the ceramic insert and the ends of the sleeve are hermetically sealed to the metal jackets of the conductors or cable. The seal is accomplished, for example, for soldering. In this manner a so-called parallel connection is easily made in which the conductors double back. A longitudinal connection can also be made in which the conductors continue in the same direction through two inner sleeves and through an outer sleeve.

Abstract: A composite propeller blade construction has fiber strands extending predominantly in a radial direction and looping around mounting hardware connecting a blade root to a rotor hub. The mounting hardware includes at least one bolt secured to the rotor hub or a shackle member secured to the hub by a mounting bolt and holding a tying bolt so that fiber strand loops forming the blade body loop around the shackle member and around free ends of the tying bolt. The radially extending fiber strands take up centrifugal forces and are enclosed by a jacket, the radially inner end of which is formed as mounting flanges screwed to a respective rim of the hub. The arrangement of the fiber loops is especially suitable for a fiber composite lightweight construction wherein the fibers form redundant load take-up paths and provide an advantageous centrifugal force and moment introduction into the structure.

Abstract: A protection ring of fiber material is constructed for containing or stopping fragments of a bursting structural component passing through a housing, such as a gas turbine housing through which a rotor blade fragment has burst by centrifugal force. Retaining pins are distributed around the housing zone to be protected. The fiber strands are looped around the retaining pins to form a fiber netting without any matrix material. Friction between fibers and pins is kept low so that the fibers can stretch along substantially their entire length for taking up impact energy. Thus, substantially the entire volume of the ring can participate in taking up impact energy and not only a localized ring portion that received an impact. A desirable lightweight structure is achieved.

Abstract: Aluminum diffusion coatings are applied to structural components of titanium alloys by two separate heat treatment steps applied to the component embedded in an aluminum powder. The first heat treatment step is performed at relatively very low temperatures for avoiding an oxygen embrittlement of the structural component by any remainder oxygen. The subsequent diffusion heat treatment is performed at higher temperatures. If desired, a getter material having a high oxygen affinity, is added to the powder mixture in which the structural components are embedded for the first treatment. The getter material binds any remainder oxygen.

Abstract: The quality or durability of an oxidation protective coating produced by alitizing or aluminizing on the surface of a structural component made of titanium or titanium alloy, is improved by adding niobium to the surface of the structural component. The addition may be accomplished prior to the aluminizing or during the aluminizing. Prior application may involve, for example, vapor deposition of the niobium. Simultaneous application involves including a niobium donator powder in the aluminizing powder mixture.