Abstract:
Verfahren zum Härten zumindest eine Teilbereichs der Oberfläche von Kolbenkronen aus Stahl, und entsprechend hergestellte Kolbenkrone aus Stahl, insbesondere für Großdieselmotoren, wobei das Härten durch Nitrieren erfolgt.
Abstract:
There are provided a highly durable and efficient refrigerating apparatus and a lubricating oil composition that uses an HFC type refrigerant and is still free from the problem of thermal hydrolysis of polyol-ester type oil and resulting generation of carboxylic acid and sludge so that the refrigerating apparatus and the lubricating oil composition may be used stably for a prolonged period of time. A lubricating oil composition according to the invention comprises as base oil components a polyol-ester type oil formed by reacting specific polyhydric alcohol with a fatty acid, to which tricresylphosphate and epoxy compound comprising glycidyl ether or carbodiimide are added at respective specific rates. A refrigerating apparatus according to the invention uses such a lubricating oil composition as refrigerator oil and comprises a sealed electric driving compressor whose sliding members are made of a material selected from iron type materials, composite materials of aluminum and carbon, iron type materials surface-treated with chromium nitride and ceramic materials.
Abstract:
A fluorine-containing benzophenone derivative of the formula (1), (2) or (3):
Φ¹ (-X¹-Q¹-R f ¹) n (1)
Φ²-X²-Q²-R f ²-Q³-X³-Φ³ (2)
Φ⁴-X⁴-Q f -X⁵-Φ⁵ (3)
wherein Φ¹ is a 2-hydroxybenzophenone structure of the formula ka-1:
(wherein Y is a hydrogen atom or a hydroxyl group, each of k and m indicates the number of bond sites, k is an integer of from 0 to 3, and m is an integer of from 0 to 3, provided that 1≦(k+m)≦4 ), n corresponds to (k+m) and is an integer of from 1 to 4, each of Φ², Φ³, Φ⁴ and Φ⁵ is a 2-hydroxybenzophenone structure of the formula ka-1 wherein (k+m) is 1, each of X¹, X², X³, X⁴ and X⁵ is a single bond or an oxygen atom, Q¹ is a single bond or a bivalent linking group having a carbon atom directly bonded to X¹, each of Q² and Q³ is a single bond or a bivalent linking group, R f ¹ is a monovalent polyfluorohydrocarbon group having from 2 to 22 carbon atoms, in which some of the carbon atoms may be substituted by ether oxygen atoms, R f ² is a bivalent polyfluorohydrocarbon group having from 2 to 22 carbon atoms, in which some of the carbon atoms may be substituted by ether oxygen atoms, and Q f is a bivalent linking group having at least one Q⁴-R f ¹ (wherein Q⁴ is a bivalent linking group, and R f ¹ is as defined above).
Abstract:
Les moteur diésel actuels dotés d'ensembles de pistons sont limités à des pressions de chambre de combustion d'approximativement 12 410 kPa (1 800 psi) alors que l'on cherche à augmenter ces pressions jusqu'à 15 170 kPa (2200 psi). Afin d'atteindre ces niveaux, l'ensemble de piston de l'invention comprend un élément de piston en acier comportant une partie cylindrique supérieure définissant une surface supérieure, une paroi tubulaire dépendante ainsi qu'un évidement de refroidissement annulaire comportant une ou plusieurs surfaces usinées de révolution autour d'un axe central. L'évidement de refroidissement est situé en-dessous de la surface supérieure et est juxtaposé à la cannelure annulaire supérieure afin d'éliminer la chaleur de celle-ci lors de l'utilisation. L'élément de piston est de préférence forgé puis usiné à des dimensions commandées avec précision. De plus l'ensemble de piston est de préférence du type articulé et comprend une jupe de piston en aluminium forgé reliée à l'élément de piston par une maneton commun.
Abstract:
The present invention relates to providing a pair of steel inserts cast-in on the inside of the piston skirt of a light metal piston for internal combustion engines. An object of the invention is to avoid using the conventional setting devices for steel inserts. According to the invention, inserts conforming to the internal shape of the piston skirt (1e) have a pair of bands (2), being joined by a connecting portion with a pair of bent portions (2b, 4a), being bent inwardly at free ends of said bands (2).
Abstract:
Pistons are described comprising a crown portion (11) which also includes a piston ring belt and gudgeon-pin bosses (18) and which crown portion comprises a ferrous alloy and a separate articulated skirt portion (12) which also includes gudgeon-pin bores (28,31,44,55) the crown portion and the skirt portion having a common gudgeon-pin wherein at least part of the skirt portion surfaces which co-operate with an associated cylinder or cylinder liner comprise a material selected from the group comprising aluminium alloys, plastics material and coated steel or cast iron. Examples are given of pistons having die-cast aluminium alloy skirts and skirts fabricated from sheet or strip metal.
Abstract:
Bei einem ölgekühlten, aus einem Kolbenunterteil und einem Kolbenoberteil zusammengesetzten Tauchkolben ist durch spezielle konstruktive Maßnahmen im Bereich der Abstützung der beiden Kolbenteile, deren Materialpaarung und der Kühlölführung sichergestellt, daß mit dem Tauchkolben hohe Zünddrücke sicher ohne nennenswerte Deformation der Kolbenteile beherrschbar sind. Durch Maßnahmen an der Unterkante des Kolbenunterteils ist außerdem sichergestellt, daß in den der Druckseite und Gegendruckseite des Tauchkolbens liegenden Umfangsbereichen immer ein genügend dicker Schmierölfilm an der Zylinderwand gegeben ist, während in den restlichen Umfangsbereichen der Schmierölfilm auf ein Minimum reduziert wird. Durch eine derartige Schmierölregulierung läßt sich der Ölverbrauch erheblich reduzieren.