Abstract: A camshaft having a tubular steel shaft and a sintered cam piece joined to the shaft. The sintered cam piece has iron tetroxide film at its surface. The camshaft is produced by assembling a powder compact to the steel shaft to provide a camshaft assembly, sintering the assembly to provide an integral assembly, correcting bending to the assembly, annealing the assembly, grinding the cam piece and effecting vaporization treatment to the assembly at a temperature lower than the annealing temperature.

Abstract: A camshaft comprising a steel shaft and a plurality of cam pieces fitted on the shaft. The cam piece is made from a sintering alloy material and bonded to the shaft by sintering. The shaft has pin-receiving holes perpendicular to the axis of the shaft. The cam piece is formed on its side surface with a pin-receiving groove. A positioning pin has a lower portion tightly fitted in the hole of the shaft and an upper portion fitted in the groove to position the cam piece with respect to the shaft during sintering.

Abstract: An assembled cam shaft including a steel cam shaft member, a journal member made of sintered material and a cam lobe. The sintered material consisting essentially of 0.5 to 4.0% by weight of carbon, 0.1 to 0.8% by weight of phosphorus, 5 to 50% by weight of copper, 1% by weight or less of manganese, 2% by weight or less of silicon, and the balance being iron and impurities.

Abstract: A camshaft having a steel shaft and cam pieces made from a sintering iron-base alloy material and fixed to the shaft by sintering. Prior to sintering, the green or pre-sintered cam piece is fitted on the shaft and positioned by a steel positioning pin, which is inserted both into a pin-receiving hole in the shaft and into a pin-receiving groove on the side surface of the cam piece. The positioning pin contains carbon less than the steel shaft. This results in that the carbon diffusion initiates at a predetermined position where the pin and the cam piece are in contact with each other and that the cam piece always shrinks about the position.

Abstract: A sintered body is produced by a process comprising the steps of mixing one or more metal powder particles with an organic binder, injection-molding the mixture to form a green body of a predetermined shape, removing the binder from the green body to form a porous body substantially made of the metal powder, and heating the porous body to a sintering temperature and holding it at that temperature to produce a sintered body, in which process the binder is removed through the sequence of the following steps: preheating the green body in an inert gas atmosphere in a temperature range that creates open pores in it; placing the green body, in which open pores have started to form, in a hydrogen gas atmosphere optionally mixed with an inert gas; holding the green body in a temperature range where the metal powder is not carburized and where the open pores will be maintained, so that the greater part of the binder is removed to form a porous body that is substantially made of the metal powder alone; and further hold

Abstract: A method for producing a ferrous sintered alloy product available for a vane used in a rotary compressor. The method comprises the steps of preparing metal powder mixture primarily containing iron, compacting the powder mixture to obtain a powder compact, sintering the powder compact to obtain a sintered body, subjecting sub-zero treatment to the sintered body, and tempering the sintered body. The sintered alloy product is used as a vane slidably disposed in a vane groove of the rotary compressor whose cooling medium is maintainable without deterioration of its property.

Abstract: A method of making a camshaft of the type having a cam piece composed of outer and inner layers which comprises the steps of molding a green cam piece in a manner that the outer and inner layers are respectively made from powders of outer-layer and inner-layer forming materials, fitting the green cam piece on a steel shaft to produce a green camshaft assembly, and sintering said green camshaft assembly at a temperature in which the materials shrink and yield a liquid phase to produce a camshaft having a cam piece diffusion-bonded to the outer periphery of the shaft.The outer-layer forming material is prepared to have an axial shrinkage of 4 to 10% and shrink more than said inner-layer forming material prepared to have an axial shrinkage of 2.5 to 6%.

Abstract: A vane pump provided with a center housing, front and rear housings holding the center housing therebetween, a rotor eccentrically disposed in the center housing and rotatably supported by the front and rear housings, a single vane diametrically movably inserted in the rotor, and a guide for regulating the projection of the vane out of the rotor. The guide comprises an axle provided centrally on each side of the vane, a circular hole formed in the inner surface of each of the front and rear housings and having a center positioned just in the middle between both centers of the rotor and the center housing, and a rolling bearing interposed between the axle and the circular hole to guide the axle in a circular path having a diameter equal to the eccentricity of the rotor. The center housing has an inner surface with a cross-sectional profile that is firstly drawn by the tip of the vane when the rotor turns and then expanded by a preselected clearance.

Abstract: Disclosed is a roller for use in a rotary compressor, which roller comprising a sintered body consisting essentially of 0.5-2.0% by weight of C, 1.0-5.0% by weight of Cu, 1.2-3.0% by weight of Mo and a balance of Fe and unavoidable impurities. In the sintered alloy, hard particles of Fe-Mo alloy are dispersed in one of pearlitic and tempering martensitic matrix, and sintered pores of the sintered body is sealed with tri-iron tetroxide. Resultant sintered body has high wear resistance and scuffing resistance capable of being used as an inverter type compressor.

Abstract: A method and device for the examination of a joint between a hollow steel shaft and a piece joined to the steel hollow shaft of a composite camshaft using ultrasonic examination. In the ultrasonic examination, the composite camshaft is put into a liquid and a probe of an ultrasonic search unit is inserted inside of the hollow steel shaft. The ultraonic examination of the joint is performed from inside of the hollow steel shaft. According to the ultrasonic examination, any kind of joint of the composite camshaft is possible, because a distance from an inside surface of the hollow steel shaft to the joint is constant. In addition, since the probe does not contact the inside surface of the hollow steel shaft, the probe is not consumed due to abrasion.

Abstract: A rocker arm for use in an internal combustion engine. The rocker arm has a portion abutting an opponent mechanical component, and at least the portion is formed of a cast iron consisting of from 2.5 to 3.7 wt % of carbon; from 1.0 to 2.0 wt % of silicon; from 0.5 to 1.0 wt % of manganese; from 10 to 20 wt % of chromium; from 0.3 to 0.7 wt % of nickel; not more than 0.3 wt % of phosphorus; not more than 0.1 wt % of sulfur; and balance iron and impurities; Carbide mainly containing chromium is uniformly precipitated from at least one of pearlitic and martensitic matrix in the cast iron.

Abstract: Disclosed is a roller for use in a rotary compressor, which roller comprising a sintered body consisting essentially of 0.5-2.0% by weight of C, 1.0-5.0% by weight of Cu, 0.5-3.5% by weight of Cr, 0.1-1.0% by weight of Co, 0.1-1.0% by weight of W and a balance Fe and unavoidable impurities. Hard particles of Cr-Co-W alloy are dispersed in one of pearlitic and tempering martensitic matrix, and sintered pores of the sintered body are sealed with tri-iron tetroxide. Resultant sintered body has high wear resistance and scuffing resistance capable of being used as an inverter type compressor.

Abstract: A vane used in a rotary compressor, and rotary compressor including the vane are made from a ferrous sintered alloy. The method comprises the steps of preparing metal powder mixture primarily containing iron, compacting the powder mixture to obtain a powder compact, sintering the powder compact to obtain a sintered body, subjecting sub-zero treatment to the sintered body, and tempering the sintered body. The sintered alloy product is used as a vane slidably disposed in a vane groove of the rotary compressor whose cooling medium is maintainable without deterioration of its property.

Abstract: A method and device for the examination of a joint between a hollow steel shaft and a piece joined to the steel hollow shaft of a composite camshaft using ultrasonic examination. In the ultrasonic examination, the composite camshaft is put into a liquid and a probe of an ultrasonic search unit is inserted inside of the hollow steel shaft. The ultrasonic examination of the joint is performed from inside of the hollow steel shaft. According to the ultrasonic examination, any kind of joint of the composite camshaft is possible, because a distance from an inside surface of the hollow steel shaft to the joint is constant. In addition, since the probe does not contact the inside surface of the hollow steel shaft, the probe is not consumed due to abrasion.

Abstract: An abrasion resistant alloy sintered in a liquid phase, which contains, by weight, 1.5 to 4.0% C, 0.5 to 1.2% Si, 1.0% or less Mn, 2.0 to less than 20.0% Cr, 0.5 to 2.5% Mo, 0.2 to 0.8% P, and the balance of Fe. The alloy is suitable for fabricating sliding parts in internal combustion engines, such as valve mechanisms.

Abstract: A camshaft in which the outer peripheral surface of a shaft (13) is provided with an axial groove (14), and a fitting member (10) is connected to the shaft (13) by liquid-phase sintering under the state in which a projection (12) on the surface of a bore (11) in the fitting member (10) is fitted into the groove (14). The projection (12) in the bore (11) of the fitting member (10) is formed so that its cross-sectional configuration is smaller than that of the groove (14) in the shaft (13). Therefore there is no possibility that the fitting member (10) made of a green compact can be damaged during the fitting or sintering.

Abstract: A fabricated camshaft having individual lobes mounted on tubular collars that are in turn mounted on an internal tubular member that is expanded between the collars to form bearing journals for the camshaft.

Abstract: A spacer expander adapted for use in an oil ring assembly of an internal combustion engine comprising a split annular shaped spring body containing a plurality of lugs extending axially from the body to bear on a single rail or double side rails, the body having a sufficiently thick cross-section to exert a radial expansive force on the side rail and cause it to follow the inner surface of the engine cylinder even if the cylinder is distorted at high speed running. The lug is thinner in thickness at least at its root portion than the body and is elastically bendable without affecting the body. Upon inclination of the piston to the cylinder, the side rail is inwardly biased by the cylinder to push a part of the lugs. However, the lugs can elastically bend independently from the body and from the other part of the lugs with the result that the outer radial face of the side rail is always maintained in operative contact with the inner surface of the cylinder.

Abstract: A composite camshaft is formed by brazing a journal to a shaft. After a brazing material is fitted into an annular groove formed on the center of the inner peripheral surface of a shaft-receiving bore in the journal, the journal is fitted onto the shaft and the brazing material is heated until it melts. The molten brazing material consequently completely fills a clearance between the inner peripheral of the shaft-receiving bore in the journal and the outer peripheral surface of the shaft, ensuring that the journal and the shaft are firmly connected.

Abstract: A hollow cam shaft for use in an internal combustion engine is disclosed. The cam shaft includes a steel pipe, a journal portion and a cam portion. The journal portion is provided at a part of the outer peripheral surface of the steel pipe and having an outer diameter smaller than that of the steel pipe. A cam lobe is assembled on the other portion of the outer peripheral surface of the steel pipe. The journal portion is formed by cutting the part of the outer peripheral surface of the steel pipe by a uniform axial length and radial depth.