Abstract: An inspection method of a rolling element includes the steps of: projecting an X-ray from a light source to a rolling element, detecting the X-ray passing through the rolling element by a detector, calculating data of the detected X-ray to form an image, and detecting a defect in the rolling element based on the image. At the step of projecting an X-ray, the light source rotates relatively around the rolling element while the X-ray is projected to an entire region of the rolling element facing the light source. At the step of forming an image, data of the X-ray for one circuit around the rolling element is calculated to generate the image.

Abstract: An inspection method of a rolling element includes the steps of: projecting an X-ray from a light source to a rolling element, detecting the X-ray passing through the rolling element by a detector, calculating data of the detected X-ray to form an image, and detecting a defect in the rolling element based on the image. At the step of projecting an X-ray, the light source rotates relatively around the rolling element while the X-ray is projected to an entire region of the rolling element facing the light source. At the step of forming an image, data of the X-ray for one circuit around the rolling element is calculated to generate the image.

Abstract: It is an object of the present invention to provide a cage that can be used in a cryogenic-temperature environment or a vacuum without providing the cage with a complicated construction and without performing special treatment and a bearing using the cage. A cage made of resin has an annular main body having a plurality of pocket portions radially penetrating the main body; and a plurality of pocket members, provided on the annular main body, which hold rolling elements of a rolling bearing. The main body is a molding of a first resin composition consisting of a first resin and a solid lubricant mixed therewith; and at least a rolling element-retaining surface of each of the pocket members is made of a second resin composition containing fluorocarbon resin as a main component thereof. The molding of the first resin composition has a tensile strength of not less than 30 MPa and a heat-resistant temperature of not less than 200° C. The second resin composition is a fluorocarbon resin composition.

Abstract: It is an object of the present invention to provide a cage that can be used in a cryogenic-temperature environment or a vacuum without providing the cage with a complicated construction and without performing special treatment and a bearing using the cage. A cage made of resin has an annular main body having a plurality of pocket portions radially penetrating the main body; and a plurality of pocket members, provided on the annular main body, which hold rolling elements of a rolling bearing. The main body is a molding of a first resin composition consisting of a first resin and a solid lubricant mixed therewith; and at least a rolling element-retaining surface of each of the pocket members is made of a second resin composition containing fluorocarbon resin as a main component thereof. The molding of the first resin composition has a tensile strength of not less than 30 MPa and a heat-resistant temperature of not less than 200° C. The second resin composition is a fluorocarbon resin composition.

Abstract: A ball bearing for use in a high-temperature, high-speed, light-load environment is proposed which includes inner and outer rings formed of heat-resistant bearing steel M50. A nitrided layer which is formed of a diffusion layer only is formed on each of the surfaces of the inner and outer rings where the raceways are formed. A chromium nitride film is further formed on the nitrided layer. The layer and film serves to prevent surface-starting peeling and smearing, thus prolonging the life of the bearing.

Abstract: A method is disclosed for producing an optical fiber composite insulator, including the steps of: preliminarily heating the insulator body in its entirety at not less than 70.degree. C., then filling said organic insulating material into the through hole while said at least one optical fiber is being stretched straight, and then curing the organic insulating material by heating in a temperature range of not less than 75.degree. C. but not more than 90.degree. C. while at least one optical fiber is kept stretched straight.

Abstract: An optical fiber composite insulator includes an insulator body in which a through hole having a substantially radially circular cross section is provided, a plurality of optical fibers passed through the through hole, and an organic insulating material gas-tightly sealing the optical fibers in the through hole, wherein a diameter of the through hole is not more than 13 mm, the optical fibers are located inside a hypothetical circle drawn on any plane orthogonal to an axis of the through hole and having a center coaxial with that of the through hole, the hypothetical circle having a diameter equal to 95% of that of the through hole, and a distance between any optical fibers is set at not less than 0.1 mm.

Abstract: An excellent optical fiber built-in type composite insulator of reduced damage rate in the producing operation and the handling operation thereof, reduced loss of initial light signal transmission and in a desired temperature range, and reduced trouble rate after thermal shock test, is provided.

Abstract: An excellent optical fiber built-in type composite insulator including at least two insulator bodies each having a penetration bore, at least one optical fiber inserted in the penetration bores, and sealing structures for the penetration bores of the insulator bodies and for a joining layer of opposing end surfaces of adjacent insulator bodies, is provided, which effectively prevents leakage of inner silicone grease, bending and breakage of the optical fiber, leakage of electric current along the penetration bores, short circuited trouble, and destruction of the insulator bodies, improves joining strength of the opposing end surfaces of the insulator bodies, and maintains the joining strength for a long period, affords a change of numbers of the insulator bodies, and facilitates the production. A method of producing such composite insulator is also provided.

Abstract: An excellent optical fiber built-in type composite insulator is provided having a reliable and durable sealing portion in a central axis penetration hole of the insulator for sealing the optical fiber in a very quick, simple and economical way with reduced members, devices and production steps. The composite insulator includes a ceramic insulator having a penetration hole in its central axis portion, at least one optical fiber inserted in the penetration hole, and sealing portions made of inorganic glass arranged at both ends of the penetration hole for sealing the optical fiber therein, and comprises recessed portions of the ceramic insulator arranged around the ends of the penetration hole, and heat generating elements arranged in the recessed portions for heating and melting the inorganic glass to form the sealing portions at the both ends of the penetration hole. The present invention provides also a method of producing the composite insulator.

Abstract: An optical fiber composite insulator including a hollow insulator body having an axial through-hole and at least one optical fiber extended through the through-hole and hermetically sealed to the inner surface of the through-hole by a sealing material. A relationship between a condition of the inner surface of the through-hole and the sealing material, a relationship between the inner diameters of the through-hole and the outer diameter of the hollow insulator body or a coating material on the optical fiber are selected to provide high insulating property, mechanical strength and airtight property of the optical fiber composite insulator.

Abstract: An excellent optical fiber built-in type composite insulator including at least two insulator bodies each having a penetration bore, at least one optical fiber inserted in the penetration bores, and sealing structures for the penetration bores of the insulator bodies and for a joining layer of opposing end surfaces of adjacent insulator bodies, is provided, which effectively prevents leakage of inner silicone grease, bending and breakage of the optical fiber, leakage of electric current along the penetration bores, short circuited trouble, and destruction of the insulator bodies, improves joining strength of the opposing end surfaces of the insulator bodies, and maintains the joining strength for a long period, affords a change of numbers of the insulator bodies, and facilitates the production. A method of producing such composite insulator is also provided.

Abstract: An optical fiber composite insulator comprises a hollow insulator body having an axial through-hole and at least one optical fiber extended through the through-hole and hermetically sealed to the inner surface of the through-hole by a sealing material. A relationship between a condition of the inner surface of the through-hole and the sealing material, a relationship between the inner diameters of the through-hole and the outer diameter of the hollow insulator body or a coating material on the optical fiber are selected to provide high insulating property, mechanical strength and airtight property of the optical fiber composite insulator.

Abstract: An excellent lightning arrestor insulator is provided having a discharge gap portion and an arrestor ZnO element device both built in a body of the insulator, comprising projected discharge electrodes arranged in the inside of the insulator body, the discharge gap portion being formed of a heat resistant protrusion arranged in the inside of the insulator body and surrounding the discharge electrodes, and a pair of metal plates and/or electrically conductive ceramic plates sandwiching the protrusion from both sides thereof and electrically connected to the discharge electrodes, the pair of plates being joined and airtightly sealed to the protrusion via an inorganic glass. The arrestor ZnO element device has a highly reliable airtight fixing and sealing structure so that accidents in a power supply or distribution line at a normal working voltage can be substantially eliminated, and damages caused by hygromeration and lightnings can be noticeably decreased.

Abstract: A zinc oxide lightning-conducting element is disclosed which includes a metal oxide sintered body mainly composed of zinc oxide, and electrodes which consist of metal vapor-deposited films provided on opposite surfaces of the sintered body in a thickness of not less than 300 .ANG. and noble metal coat films coated onto the metal vapor-deposited films. At least one kind of a metal oxide is added and mixed into the zinc oxide.

Abstract: In a lightning arrestor insulator wherein a ZnO element having voltage non-linear resistant characteristics is embedded in an insulator body and integrally fixed with a glassy bonding material, the glassy bonding material has a thermal expansion coefficient smaller than either of those of the ZnO element and the insulator body. As the glassy bonding material, a low melting PbO-B.sub.2 O.sub.3 system glass having a composition to separate, during solidification, low expanding ceramic crystals is preferably employed.

Abstract: A lightning arrester insulator in which a voltage non-linear resistor having a major constituent of zinc oxide is integrally fixed in a longitudinal bore in the insulator with a layer of an inorganic adhesive agent which is interposed between an outer surface of the resistor and an inner wall surface of the insulator defining the longitudinal bore. A contact angle of the adhesive agent layer defined by each end face thereof and an associated end part of the inner wall surface is held within a range of 10 to 60 degrees. To establish the contact angle, at least one of the end face of the adhesive agent layer and the associated end part of the inner wall surface of the insulator is inclined with respect to the longitudinal centerline of the longitudinal bore. Each end surface of the voltage non-linear resistor is spaced from the corresponding end of the adhesive agent layer axially inwardly along the longitudinal centerline of the longitudinal bore.