There are provided a copper alloy for a bearing and a bearing in which a Mn—Si compound is prevented from being broken and becoming a foreign matter. The copper alloy for a bearing and the bearing according to the present invention contain 25 wt % or more and 48 wt % or less of Zn, 1 wt % or more and 7 wt % or less of Mn, 0.5 wt % or more and 3 wt % or less of Si and 1 wt % or more and 10 wt % or less of Bi, the balance consisting of inevitable impurities and Cu, and are characterized in that the average width value among Mn—Si primary crystal particles dispersed in a sliding surface on which a counter shaft slides is 3 μm or more.

There are provided a copper alloy for a bearing and a bearing, which can prevent seizure in Mn-Si primary crystals. The copper alloy for a bearing and the bearing according to the present invention contain 25 wt % or more and 48 wt % or less of Zn, 1 wt % or more and 7 wt % or less of Mn, 0.5 wt % or more and 3 wt % or less of Si, and 1 wt % or more and 10 wt % or less of Bi, the balance consisting of inevitable impurities and Cu, and are characterized in that, in a sliding surface on which a counter material slides, the proportion of triangles having an area of 5000 μm.sup.2 or more and including no Bi particle with a circle equivalent diameter of 10 μm or more, among triangles having the closest three Mn-Si primary crystals as apices, is 20 % or less.

Tapered bearings are provided for use on each end of each link arm on an agricultural seed row planter mounted on a toolbar. The bearing is a low friction material and greaseless. The tapered design of the bearings allows the bearings to be adjusted as wear occurs, by tightening the link arm mounting nut which extends through the tapered bearing. The tapered bearing has an increased life and reduced maintenance, as compared to prior art roller bearings.

The present invention highlights a lemon shaped guide that may be used in a rotating machine to suppress excessive rubbing. Rubbing, between a rotor and a guide, is critical in industries; since, it may even lead to severe damages. The lemon shaped guide is based solely on the mechanical design, that is more economical and quickly implementable than the other traditional techniques, such as circular guide, or more advanced sophisticated devices, for example, magnetic bearings. The lemon shaped guide is designed from two circles—having the same radius, and centers on the same line with some distances—which are the most significant designing parameters. Once equipped with a rotating machine, the lemon shaped guide may perform better at minimizing rubbing, between rotor and stator operating at higher speed, than the traditional circular shaped guide.

A powder metallurgically produced, wear-resistant, and highly thermally conductive copper-based sintered alloy as matrix is disclosed. The sintered alloy includes a powder mixture of a copper-base powder, of a hard phase with a total share of 8 to 40% by weight, of a solid lubricant with a total share of 0.4 to 3.8% by weight, of a pressing additive with a total share of 0.3 to 1.5% by weight, and production-related impurities. The powder mixture includes at least 55% by weight of the copper-base powder.

A special brass alloy containing 62.5 to 65% by weight Cu, 2.0 to 2.4% by weight Mn, 0.7 to 0.9% by weight Ni, 1.9 to 2.3% by weight Al, 0.35 to 0.65% by weight Si, 0.3 to 0.6% by weight Fe, 0.18 to 0.4% by weight Sn and Cr, either alone or in combination, ≤0.1% by weight Pb, the remainder consisting of Zn and inevitable impurities.

A wrought alloy for a bearing material for use as valve guide or in turbochargers of internal-combustion engines operated with ethanol-containing fuels The composition of the wrought alloy is as follows in wt%: Zn: 25.0 - 34.0%; Fe: 0.8 - 1.2%; Sn: 0.8 - 1.2%; Al: 1.3 -1.7%; Si: 0.2 - 0.45%; and Pb: up to 0.1%, with the balance being copper and unavoidable impurities The sum total of all elements not belonging to the group of the elements copper, zinc, iron, tin, aluminum and silicon is at most 0.3 wt%. The alloy has a microstructure including precipitates in the form of silicides with a fraction of 0.5 to 2.0 vol%.

A copper alloy having a high corrosion resistance for a wide range of different lubricants, in particular different base oils and a variation of lubricant additives. The property of a low corrosion tendency for different tribological systems is also combined with good mechanical properties, and a high strength in particular. The alloy has a low wear and coefficient of friction. The lubricant-compatible copper alloy is suitable for producing components that come in contact with lubricant and are exposed to friction stresses, such as gear components, for example synchronizer rings. A method for manufacturing such components and a gear having at least one such component is also disclosed.

A sliding member includes a back-metal layer and a sliding layer made of a copper alloy. The back-metal layer is made of a hypoeutectoid steel including 0.07 to 0.35 mass % of carbon, and has a structure including a ferrite phase and pearlite. The back-metal layer includes a pore existing region including a plurality of closed pores that are not open to a bonding surface when viewing a cross-section perpendicular to a sliding surface. The closed pores have an average size of 5 to 15 μm. The pore existing region extends from the bonding surface toward an inner portion of the back-metal layer, and has a thickness of 10 to 60 μm. A ratio V2/V1 of a total volume V2 of the closed pores to a volume V1 of the pore existing region is 0.05 to 0.1.

The invention relates to a sliding element consisting of a copper-zinc alloy containing the following components (in % by weight): 60.0 to 64.0% Cu, 0.2 to 0.5% Si, 0.6 to 1.2% Fe, optionally also up to a maximum 1.5% Sn, optionally also up to a maximum 0.25% Pb, optionally also up to a maximum 0.08% P, the remainder being Zn and unavoidable impurities. The copper-zinc alloy has a grain structure consisting of an α- and β-phase with a volume content of the α-Phase of at least 90%, and iron silicides are embedded in the grain structure.