Abstract: Method of manufacturing a radially corrugated expander-spacer for a piston oil ring assembly, having inner and outer crowns alternately and successively laid, which can prevent its both terminal ends from nesting together during assembling of the piston oil ring assembly. The inner crowns each includes an inner peripheral piece and an opening having a circumferential width larger than that of the inner peripheral piece, and the outer crowns each includes an outer peripheral piece and an opening having a circumferential width larger than that of the outer peripheral piece. The manufacturing method comprises the steps of filling thermosetting synthetic resin having bonding force with respect to metals into the openings of inner crowns at both terminal ends of the expander-spacer, and thereafter, setting the thus filled thermosetting synthetic resin so that the resin is fixedly secured to the openings of the inner crowns at both terminal ends of the expander-spacer.

Abstract: A coating material for use in oil-free type sliding members comprising a powder mixture prepared by mixing a finely powdered resin mixture composed of 70 to 90 weight % of finely powdered tetrafluoroethylenehexafluoropropylene copolymer resin and 10 to 30 weight % of finely powdered polyimide resin with 5 to 15 weight %, based on the total weight, of one or more of ZrO.sub.2, SiC, Si.sub.3 N.sub.4, Al.sub.2 O.sub.3, carbon C and tetrafluoroethylene resin of 0.2 to 1.0 micron meter in particle size is applied, as a suspension, onto sliding members, and baked to form a coating thereon.

Abstract: A hollow rotor for movable vane pumps and the like having a pair of right and left cup-shaped bodies each being separately shaped from steel or aluminum alloy in the form similar to either of axially bisected parts of a complete rotor. The right and left cup-shaped bodies have the respective open side faces abutted and joined to each other by butt resistance welding to be incorporated into the complete hollow rotor.

Abstract: A composite camshaft having a plurality of ferrous fitting members, such as cam lobes and journals, firmly bonded to a steel shaft by sintering in the presence of a liquid phase. The fitting members are fabricated as a green compact from metal powders and pre-sintered to axially shrink the compact by one-half a preselected allowance of shrinkage. Thereafter the pre-sintered fitting members are fitted on the shaft and sintered to axially shrink the compact by the remaining allowance of shrinkage and metallurgically join the shaft.

Abstract: A rotary compressor is provided with a rotary sleeve mounted in a center housing for rotation with a plurality of vanes movable in a rotor which is eccentrically disposed in the rotary sleeve. An air-bearing room is defined between the outer periphery of the rotary sleeve and the inner periphery of the center housing and supplied with air through an inlet internally connected to the discharge chamber or compression working space under the maximum pressure. A multiplicity of air-accumulating grooves are formed in either or both in the outer periphery of the rotary sleeve and the inner periphery of the center housing.The air-accumulating groove is composed of a suction portion gradually inclined from the peripheral direction and a compression portion sharply inclined from or perpendicular to the peripheral direction.

Abstract: An apparatus provided in a rotary compressor comprising an air-bearing room (40) defined between the inner periphery of the center housing (22) and the outer periphery of the rotary sleeve (30) to have an air-bearing effect for floatingly supporting the rotary sleeve rotating with a plurality of vanes. The air-bearing room (40) is supplied with discharge-pressure air from the discharge chamber (43) or the maximum-pressure air from the compression side working space (43). Guide grooves (74) are partly or fully formed in either or both of the inner periphery of the center housing and the outer periphery of the rotary sleeve. Air enters the air-bearing room and flows along the guide grooves to axially equalize the bearing effect.

Abstract: A rotary compressor provided with a center housing and side housings, a rotary sleeve mounted for rotation in the housings and a plurality of vanes radially, slidably fitted in a rotor which is eccentrically disposed in the rotary sleeve. The rotary sleeve has its opposite side surfaces formed with a plurality of air-guide grooves. As the rotary sleeve rotates, the air-guide grooves guide air to flow from the compression working space in the rotary sleeve to the air-bearing room between the outer periphery of the rotary sleeve and the inner periphery of the center housing and from the air-bearing room to the suction working space in the rotary sleeve so that an air film is formed in each of the both side clearances between the both side surfaces of the rotary sleeve and the inner surfaces of both side housings.

Abstract: A wear-resistant member and method for producing the same which member may form a movable member in an internal combustion engine which is subjected to high pressure such as a rocker arm, tappet, cam, valve or valve seat. The member is formed as a combination of a ferrous sintered body and a ferrous base body having a common surface. The sintered body is formed from a compressed powder body disposed in contact with the ferrous base body. The powder body, in a preferred embodiment, consists of 0.5 to 7.0% by weight carbon, 0.1 to 5.0% phosphorus, the balance being iron, and having a porosity of 12 to 20% by volume at least 40% of which is pores having a pore size of not more than 300 .mu.. The combined powder body and ferrous base body are heated to a temperature higher than the liquid-phase temperature of the powder body but lower than the melting point of the ferrous body to sinter the powder body.

Abstract: A steel piston ring comprises a base material of stainless steel, a nitrided layer covering at least the edge of the ring adapted to slide along a cylinder wall of an internal combustion engine, and an oxide film over the nitrided layer on the edge of the ring. Suitable oxide films include phosphate oxide and triion tetroxide.

Abstract: A journal assembled to a rotary shaft has its outer portion made of solid phase sintered alloy having 10% to 30% by volume of sintering pores inpregnated with lubricating oil and its inner portion is made of a liquid phase sintered alloy being sinterable at the same temperature as the solid phase sintered alloy. The outer portion is wear-resistant and well lubricable due to the oil impregnated therein. The inner portion is tightly secured to both the outer portion and the rotary shaft because the liquid phase sintered alloy is metallurgically diffusion-bonded to both the solid phase sintered alloy and the rotary shaft.

Abstract: A piston ring for control of the oil on a cylinder wall that is comprised of thin upper and lower ring members disposed to contact the cylinder wall and an intermediate corrugated expander-spacer. The upper ring member has a headed rivet with the upper head disposed to engage a groove in the piston while the lower head engages an opening defined by the corrugation of the expander-spacer. In such a manner the upper ring member and the expander-spacer are prevented from rotating with respect to the piston.

Abstract: A rotor for a rotary compressor having a metal central portion integral with two opposite end portions that are fiber-reinforced metal matrix composites having a matrix metal common to the central portion. Such rotors may be made by pressing inorganic fibers to form the end portions of the rotor, arranging the end portions in an opposing relationship in a mold to form the central portion between the end portions. Molten metal is placed into the mold such that it infiltrates the porous end portions while forming the central portion. Solidification of the metal forms fiber-reinforced metal-matrix composite end portions integral with the central portion.

Abstract: A piston ring provided with a nitriding layer at entire surfaces of the piston ring body to form a compound layer and a diffusion layer, so that a compound layer is formed over the diffusion layer. From an outer peripheral surface of the piston ring body, the compound layer or both compound layer and diffusion layers is removed, and the plating or spraying layer is formed on the exposed diffusion layer or the exposed surface of the piston ring body.

Abstract: A rotary compressor with a center housing and a rotary sleeve mounted in the center housing for rotation with a plurality of vanes radially slidably fitted in a rotor which is eccentrically disposed in the rotary sleeve, and an air-bearing room defined between the outer periphery of the rotary sleeve and the inner periphery of the center housing to floatingly support the rotary sleeve, characterized in that a part of compressed air in the rotary compressor is injected into the air-bearing room through the throttles provided in the compression side wall of the center housing to prevent the rotary sleeve from scuffing the inner periphery of the center housing.

Abstract: A piston ring with a nitriding layer on entire surfaces thereof except an outer peripheral surface, and a plating or a spraying layer on the outer peripheral surface of the piston ring.

Abstract: A composite camshaft having a plurality of fitting members, such as cam lobes and journals, fabricated from metal powders having a composition of an Fe-C-Cu system which contains 17-35% by weight of Cu and joined to a steel shaft by a binding effect of Cu, which melts out of the fitting member and full penetrate a clearance between the fitting member and the steel shaft to join them as one body.

Abstract: A method of forming a rotor for a vane-type rotary pump. The rotor is generally cylindrical with a plurality of vane slots. A tubular member having generally flat sections separated one from the other by corner portions is formed into the rotor by forming the flat sections into slots by deforming the tubular member. The slots are thereafter formed into the vane slots with a die and the corner portions are formed into the outer peripheral surface of the rotor, also using a die.

Abstract: A rotary compressor housing is outwardly formed with reinforcing grids in the form of square, diaper or honeycomb. The reinforcing grids allow the intermediate wall portions between the bolted wall portions to thermally expand as much as the bolted wall portions, resulting in that the inner periphery of the center housing always keep its circularity when the inner temperature rises due to an unavoidable compression of air.

Abstract: A vane-type rotary pump constructed such that a rotor, into and out of which a vane can freely move, is rotatably installed in the central housing. The rotor is rotatably supported through a bearing by side housings flanking the central housing on both sides, the side housings being composed of shaft housing parts to hold the bearing and of side plate parts on the rotor side. The shaft housing parts are fabricated of either an iron base material or a composite material of whisker fibers. The side plate parts are fabricated of either a light metal or a light alloy and the shaft housing parts and side plate parts are joined together integrally. The rotary pump of such a structure is characterized by reduced weight and improved durability.

Abstract: A wear resistant ferro-based sintered alloy comprising a base structure comprising a mixture of 20 to 50% by area ratio of pearlite, 15 to 40% by area ratio of bainite and 15 to 40% by area ratio of martensite, and 3 to 20% by area ratio of ferromolybdenum particles dispersed uniformly in the base structure is disclosed.