Composite metal powder for sintered bearing, and sintered oil-retaining bearing

Abstract

Composite metal powder for sintered bearings, prepared by coating surface layers of particles of iron powder with 10 wt.% to less than 30 wt.% of copper based on the iron powder so that the particle size of the coated iron powder is at most 80 meshes, the content of the powder of at most 350 meshes is at most 30%, and the specific surface area of the powder is 450-750 cm<SP>2< / SP> / g according to the subsieve sizer method. This metal powder can provide an oil-retaining bearing for motors, which is capable of providing a low gas-permeability without decreasing the oil content and which has a low and constant coefficient of friction, a high corrosion resistance, a high adaptability and a high durability, readily at a low cost.

Description

technical field

[0001] The present invention relates to a composite metal powder for sintered bearings and oil-containing sintered bearings. This kind of bearings can be used as bearings for motors, etc., which is not only simple but also inexpensive, and can obtain low air permeability even without reducing the oil content, and has little friction and maintains In a constant state, it is an oil-impregnated bearing with strong corrosion resistance, excellent running-in performance and high durability. Background technique

[0002] For the sintered body for bearings made of copper-coated iron powder, in No. 55-38019, it is proposed to use 30-60% copper-coated iron powder. Foil-like powder formed by layering the same metal or alloying metal.

[0003] Japanese Patent Publication No. 7-54126 proposes that in order to improve the properties of sintered oil-impregnated bearings, it is considered necessary to lower the air permeability and add copper-graphite composite powder. In...