Abstract: A rolling element bearing having inner and outer rings and a plurality of rolling elements where one, two or at least one but not all of the rolling elements of the plurality of rolling elements is harder than the other of the plurality of rolling elements and harder than the rings.

Abstract: The use of bismuth-compounds in an extreme pressure grease lubricant composition for rolling bearing applications can extend the useful service life of rolling bearings. The bismuth can be used as an additive, preferably an EP additive, or as a soap or non-soap thickener. The invention further relates to a method for preparing an extreme pressure lubricant composition in which a bismuth containing soap or thickener is mixed with an oil and optionally one or more EP- or other additives.

Abstract: A rolling element bearing comprises an outer ring and an inner ring which enclose a bearing space containing rolling elements which are in rolling contact with the raceways of both rings. At least the contact surface layer of one of the rings and/or rolling elements consists of a zirconium material. At least one of the rings has a composite layered structure comprising an outer layer of steel facing away from the bearing space and an inner layer of a zirconium material.

Abstract: A bearing comprises two opposing ring and a single row of rolling balls accommodated in the raceways of each of the rings. At least one of the rings carries an ultrasonic scanning device for scanning specific areas of the other ring upon relative rotation of the rings. The ultrasonic scanning device is opposite the other ring next to the raceway of said ring, and is directed such that ultrasonic waves produced thereby impinge upon the raceway of the other ring sidewardly.

Abstract: A rolling element bearing includes an outer ring and an inner ring which enclose a bearing space containing rolling elements. The rings are made of steel. At least one of the rolling elements comprises, at least partially as a zirconium material which is harder and stiffer than the material of the other rolling elements which are comprised of steel. Walls of indentations which are formed in the rings by solid contamination particles between the rings and one of the rolling elements having about the same hardness as the rings, are compressed as soon as the zirconium material rolling element with a substantially higher hardness than the rings overrolls the walls. Thereby, the smooth characteristic of the raceways is restored. Only small holes are left in the rings, which do not have a negative influence on the running properties of the bearing. In these small holes, minute quantities of lubricating oil are collected, which help the lubrication of the rolling elements in case of oil starvation.

Abstract: The invention relates to an electrode for electrochemical machining. An electrode comprising a plurality of electrode segments separated by insulating material. As desired, different voltages are applied to each of the electrode segments giving control over the amount of material locally removed from the metal piece. The invention also relates to a method of electrochemical machining.

Abstract: The invention relates to electrochemical machining of metal pieces, and, in particular, rings of bearings, in a controlled way. To achieve this process, parameters, such as current, are actively controlled. This allows the raceway to be completed sooner and with a smoother, more circular surface. In addition the active control makes the formation of more complex forms possible and is suitable for the cheap manufacture of trilobed raceways.

Abstract: The present invention relates to a polymer thickener for lubricant grease compositions, wherein the thickener comprises a mixture of (1) a high molecular weight (co- or homo-)polymer of propylene with a weight average molecular weight .gtoreq.200,000 and (2) a low molecular weight (co- or homo-)polymer of propylene with a weight average molecular weight .ltoreq.100,000. The invention further relates to a lubricating grease composition comprising a lubricating oil and the above polymeric thickener, as well as a method for preparing said grease composition. Also, the invention relates to the use of such a polymer thickener in the preparation of lubricating grease compositions with improved oil bleeding characteristics at low temperature and improved noise characteristics and/or improved mechanical stability.

Abstract: A greased lubricated rolling element bearing including an inner ring, an outer ring, a plurality of rolling elements disposed between said rings, and a cage for holding the rolling elements at a predetermined mutual spacing, has a lubricating grease composition present on the surfaces of said rings, said rolling elements and said cage. The cage is coated on at least the parts of its surface that are in sliding contact with said rolling elements, said inner ring or said outer ring, with a solid lubricant containing coating for lowering the running temperature of at least the cage. The solid lubricant containing coating preferably comprises a disulfide and/or diselenide of a Group V or VI transition metal, more preferably MoS.sub.2 and/or WS.sub.2 in combination with an organic resin such as PTFE.

Abstract: A polymer thickened lubricating grease composition with improved resistance to high operating temperatures (constant and/or peak), containing 1) a lubricating base oil, 2) a polymeric thickener, containing a) a high melting point component comprising at least one polymer with a melting point (ASTM D-2117) of more than 200.degree. C., especially more than 225.degree. C., and b) a low molecular weight component comprising a (co- or homo-) polymer of propylene with a weight average molecular weight <100,000, and 3) optional further lubricating grease additives. The polymer thickener of the grease preferably further contains c) a high molecular weight component comprising a (co- or homo-) polymer of propylene with a weight average molecular weight >200,000. The grease preferably has a dropping point of >150.degree. C., more preferably 180.degree.-220.degree. C., and is suitable for use in high operating temperature applications.

Abstract: The invention relates to a method of manufacturing a roller bearing comprising a cage made from a thermoplastic polymer-containing material. By cross-linking the polymeric material its properties, such as form retention and compatibility with lubricants, are improved. A roller bearing provided with a cage made from suitably cross-linked thermoplastic polymer-containing material can be used even at temperatures above the melting point of the polymer. According to the invention a roller bearing is manufactured by forming a cage from thermoplastic polymer-containing material, providing it with rotating bodies and only then cross-linking the material. This avoids damage to an otherwise already rigid cage during the insertion of the rotating bodies.

Abstract: A taper roller bearing comprises an inner ring and an outer ring having tapered raceways, a bearing space in which tapered rollers are arranged, as well as a cage for mutually spacing the rollers. A grease retainer is connected to the outer ring. The grease retainer is situated next to the inner ring part having the smallest raceway diameter. The retainer comprises a ring-shaped channel in the inner space of which grease can be accommodated. The channel has apertures for communicating the channel inner space with the bearing space.

Abstract: An electrically conducting polymer thickened grease composition containing1) a lubricating base oil,2) a polymer thickener,3) an electrically conducting component,4) optional further additives, is provided.The polymeric thickener is a mixture of (1) a (co- or homo-)polymer of propylene with a weight average molecular weight >200,000 and (2) a (co- or homo-)polymer of propylene with a weight average molecular weight <100,000. The electrically conducting component is preferably a metal containing additives, an anti-static agents or an electrically conducting solid. The grease composition can conduct electricity through the parts of a roller bearing, not only under static conditions, but also during use. This makes the greases especially suited for use in roller bearings with rotating electrical contacts. The grease can further reduce or prevent the build-up of static electricity and spark formation in roller bearings.

Abstract: A cage for a rolling element bearing, comprising elastically deformable prongs, each pair of prongs defining a cage pocket in which a rolling element can be accommodated by snapping-in. The thickness dimension of each prong, perpendicular with respect to its surface facing the corresponding cage pocket, is gradually diminishing, in the direction towards the free end of the prong. Preferably, the thickness dimension of each prong is diminishing, in general, according to a parabolic function. Thereby, the highest possible retaining force for the rolling elements is obtained, and yet the strains in the prongs upon assembly of the rolling elements are as low as possible.

Abstract: A hub unit comprises a wheel bearing and a driving axle stub which is situated in a correspondingly shaped, concentric opening in the rotatable ring of the wheel bearing, and in the direction of rotation interacts by unround shapes with the ring which driving axle stub has an axle end projecting from the opening in the ring. The axle end interacts with the inner periphery of a cup spring whose outer periphery is supported under pre-tension on the ring. The cup spring is accommodated in a peripheral groove provided in the axle end.

Abstract: A method for analysing regularly recurring mechanical vibrations comprises the steps of plotting an amplitude/time spectrum associated with the vibrations, dividing the amplitude/time spectrum into time intervals shorter than the shortest time lapse between two consecutive excitations, subjecting those parts of the amplitude/time spectrum defined by each time interval to a Fourier transformation in order to obtain an amplitude/vibration-frequency interval spectrum associated with each time interval, and subjecting those amplitudes in each amplitude/vibration frequency interval spectrum associated with certain vibration frequencies to a Fourier transformation in order to obtain an excitation-frequency spectrum associated with the respective vibration frequency.

Abstract: Bearing assembly for a vehicle hub comprising two coaxial rolling bearings having inner races and outer races, the outer races being accommodated in a common outer bush, which outer bush is provided with a flange and hub for fixing a vehicle component thereto, the inner races being accommodated on a common central element, the rolling bearings being supported on the central element and the outer bush under initial load in the axial direction.

Abstract: A rolling bearing comprises an inner race and an outer race which together enclose a bearing space in which rolling elements are accommodated, which bearing space is sealed off by means of seals fixed on the outer race. In order to prevent oil leakage, provision is made for the fastening between each seal and the outer race to be liquid-tight. The outer race can comprise at least one groove in which a seal is accommodated, while an elastic shut-off element can be provided, which shut-off element is accommodated in the groove.

Abstract: The invention relates to a method of manufacturing a seal for a roller bearing, for instance a ball bearing. The seal according to the invention is formed from a thermoplastic polymer-containing material which is subsequently cross-linked under the influence of radiation, for example .beta.-radiation. This allows the use of seals manufactured according to the invention at near or even above the melting point of the non-cross-linked thermoplastic polymer being employed. Due to the invention a large number of cheap polymeric materials have become suitable for the manufacture of seals, and due to the cross-linking the swelling caused by lubricants can be reduced considerably.

Abstract: A bearing unit for a vehicle wheel, comprising a three-point or four-point bearing with an inner race and an outer race, each having a bearing groove containing a series of rolling bearings, which inner race is provided with elements for fixing the bearing to the vehicle suspension. A flange pointing radially outwards relative to the outer race is also provided, which outward-pointing flange interacts with and/or is connected to a flange pointing radially inwards relative to the outward-pointing flange.