Manufacture of bearings
OwnerFriedrich Heckinventor
Life of this patent
Estimating the term…
Abstract
A lined bearing is made by tinning at least the radially inner surface of a bearing ring, providing an atmosphere of water vapour adjacent the tinned surface to which a flux is also supplied, and centrifugally casting on the lining material. Tinning can be achieved by applying a slurry of tin powder in a flux solution, e.g. an aqueous zinc chloride solution, followed by heating at least to a tinning temperature. Further flux solution can be sprayed onto the hot tinned surface in the centrifugal casting machine to form the desired atmosphere and to disperse the flux as fine particles. Quenching by spraying on cold water preferably commences immediately after casting of the white metal or other lining material begins.
Claims23
In a method of making a lined bearing which comprises applying a layer of metallic bonding material selected from tin and tin alloys to the radially inner surface of a bearing ring and centrifugally casting on a layer of a lining material, the improvement which comprises supplying the bonding material in the form of a powder as a slurry with water and a flux at the radially inner surface of the bearing ring, heating the ring to at least a tinning temperature, being a temperature sufficient to cause conversion of water to steam, applying a flux/water mixture to the thus applied layer of bonding material on the radially inner surface of the hot bearing ring and, without intermediate cooling, centrifugally casting on the layer of lining material.
A method of making a lined bearing which comprises the steps of
- applying a layer of a metallic bonding material to at least the radially inner surface of a bearing ring,
- heating the thus-treated bearing ring to a temperature at least as high as the melting point of the bonding material, said temperature being sufficient to cause vaporization of water to steam,
- thereafter projecting water and flux, the flux being in the form of a solution, onto the hot radially inner surface of the bearing ring, thereby to cause sudden formation of steam, to cause a fine distribution of the flux, and to establish reducing conditions over the applied layer of bonding material, so that any metal oxides formed during application of said bonding material are reduced, and
- then centrifugally casting a layer of lining material over said layer of bonding material, said centrifugal casting step being carried out in the presence of the flux and while said reducing conditions are maintained.
In a method of making a lined bearing which comprises applying a layer of bonding material to at least the radially inner surface of a bearing ring and centrifugally casting a layer of lining material over said layer of bonding material, the improvement which comprises providing at the radially inner surface of the bearing ring a slurry comprising a bonding material selected from tin and tin alloys in the form of a powder, water and a flux, and heating the ring at least to the melting point of the bonding material while rotating the bearing ring about a substantially horizontal axis whereby the bonding material is essentially uniformly distributed over the radially inner surface of the ring.
A method of making a lined bearing which comprises the steps of applying to at least the radially inner surface of a bearing ring a slurry of powdered metallic bonding material, water and a flux, heating the thus treated ring and the bonding material thereon at least to the melting point of the bonding material so as to form a layer of bonding material on the radially inner surface of the bearing ring, establishing a steam-containing reducing atmosphere over the applied layer of bonding material which atmosphere reduces any metal oxides formed during application of said bonding material, and centrifugally casting a layer of lining material over said layer of bonding material, said centrifugal casting step being carried out in the presence of a flux and while said atmosphere is being maintained.
Dependencies are inferred from the claim text.