An example bushing of a hydraulic hammer tool includes a bulk region and an inner region. The inner region has a relatively greater hardness than the bulk region. The inner region may also be compressively stressed, while the bulk region may have tensile stress. The stress and/or hardness profile of the bushing may enhance its resistance to wear and galling defects when a hammer of the hydraulic hammer tool is held in alignment by the bushing. The bulk region of the bushing may be relatively soft, resulting in the bushing having a relatively high level of toughness. The bushing may be formed using medium to high carbon steel by rough forming the bushing, hardening the bushing, tempering the bushing, induction hardening the inner region of the bushing, and then quenching the inner region.

A constant velocity universal joint includes an inner ring and an outer ring. A cage is disposed between an outer spherical surface of the inner ring and an inner spherical surface of the outer ring, and has windows in which respective balls are received. The cage has ball contact surface areas with which the balls come into contact, and includes soft portions that are lower in hardness than the ball contact surface areas. The soft portions are formed by local heat treatment at portions of the windows that are kept out of contact with the balls or surface portions around the windows.

A bearing component such as a bearing ring includes a metallic base body and at least one alloy steel coating on the base body, the coating being applied to the base body by deposition welding. The base body is preferably non-alloy steel or cast iron, and the alloy includes at least one carbide-forming transition metal such as niobium, tantalum, zirconium, titanium, hafnium, tungsten, molybdenum, vanadium, or manganese. The coating can form a raceway of the bearing component or a structural element such as a flange. Also a method of forming such a bearing component is provided.

An example bushing of a hydraulic hammer tool includes an outer region and an inner region. The inner region has a relatively greater hardness than the outer region. The inner region may also be compressively stressed, while the outer region may have tensile stress. The stress and/or hardness profile of the bushing may enhance its resistance to wear and galling defects when a hammer of the hydraulic hammer tool is held in alignment by the bushing. The outer region of the bushing may be relatively soft, resulting in the bushing having a relatively high level of toughness. The bushing may be formed using medium to high carbon steel by rough forming the bushing, hardening the bushing, tempering the bushing, and induction softening the outer region of the bushing.

A bearing includes a ring unit including an outer ring and an inner ring. The inner ring is surrounded by the outer ring and shares a common axis. The outer ring includes at least one first recess, and the inner ring includes at least one second recess. Each of the at least one first recess and the at least one second recess is filled with a first durable material elements by way of welding. At least one roller unit including multiple rollers which rolls between the inner and outer rings. The rollers contact the multiple first durable material elements. The hardness of the multiple first durable material elements and the hardness of the rollers are higher than that of the ring unit so as to increase the life of use of the bearing and reduce manufacturing cost.

The invention relates to a method for producing a rolling bearing ring featuring an improved robustness against the formation of white etching cracks (WEC), wherein the rolling bearing component, which is made of a hypo-eutectoid heat-treated steel containing C in an amount of 0.4-0.55% and Cr in an amount of 0.5-2.0% in order to form a hardened boundary layer, is inductively heated, then quenched and subsequently tempered.

There is provided a carburized bearing that is excellent in rolling contact fatigue life with a change in structure under a hydrogen-generating environment. In the carburized bearing, a chemical composition of a core portion consists of, in mass %, C: 0.25 to 0.45%, Si: 0.10 to 0.50 %, Mn: 0.40 to 0.70 %, P: 0.015% or less, S: 0.005% or less, Cr: 0.80 to 1.50%, Mo: 0.17 to 0.30%, V: 0.24 to 0.40%. Al: 0.005 to 0.100%, N: 0.0300% or less, O: 0.0015% or less, and the balance being Fe and impurities, and satisfies Formula (1) to Formula (4) described in the present specification. A proportion of a total area of CaO—CaS—MgO—Al.sub.2O.sub.3 composite oxides with respect to a total area of oxides in the carburized leaping is 30.0% or more, and a number density of oxides having an equivalent circle diameter of 20.0 μm or more is 15.0 pieces/mm.sup.2or less.

A bearing unit having a stationary radially outer ring provided with a raceway, a radially inner ring rotatable about a central rotation axis (X) of the bearing unit and provided with a raceway, a row of rolling elements interposed between the radially outer ring and the radially inner ring, at least one sealing device mounted by means of interference on the radially outer ring and in sliding contact with the radially inner ring, wherein both the radially outer ring and the radially inner ring are made of low carbon steel with a minimum percentage by weight of carbon equal to 0.42%, and a central portion of the radially outer ring situated along the raceway and a central portion of the radially inner ring situated along the raceway are heat treated by means of induction hardening.

A bearing component formed from a steel alloy having from 0.7 to 0.9 wt. % carbon, from 0.05 to 0.16 wt. % silicon, from 0.7 to 0.9 wt. % manganese, from 1.4 to 2.0 wt. % chromium, from 0.7 to 1.0 wt. % molybdenum, from 0.03 to 0.15 wt. % vanadium, from 0 to 0.25 wt. % nickel, from 0 to 0.3 wt. % copper, from 0 to 0.2 wt. % cobalt, from 0 to 0.1 wt. % aluminum, from 0 to 0.1 wt. % niobium, from 0 to 0.2 wt. % tantalum, from 0 to 0.025 wt. % phosphorous, from 0 to 0.015 wt. % sulphur, from 0 to 0.075 wt. % tin, from 0 to 0.075 wt. % antimony, from 0 to 0.04 wt. % arsenic, from 0 to 0.002 wt. % lead, up to 350 ppm nitrogen, up to 20 ppm oxygen, up to 50 ppm calcium, up to 30 ppm boron, up to 50 ppm titanium, the balance iron, together with any unavoidable impurities.

A method of manufacturing a slide of a variable oil pump for a vehicle includes preparing a molded body for a slide of a variable oil pump using prealloy powder including, in percent (%) by weight of the entire composition, 0.45 to 0.55% of carbon (C), 2.8 to 3.2% of chromium (Cr), 0.45 to 0.55% of molybdenum (Mo), 0.35 to 0.5% of manganese (Mn), 0.1 to 0.25% of sulfur (S), and the remainder of iron (Fe) and inevitable impurities. A sintered body is prepared by sintering the molded body. The sintered body is slowly cooled such that a temperature of the sintered body reaches a first temperature range and rapidly cooled when the first temperature range is reached.