Macrocomposite guideway and rail produced therefrom

Abstract

A method of producing a macrocomposite linear guideway, wherein the “traditional” or existing rail material (e.g., hardened steel) is maintained as the wear resistant, low friction material in a layer having a surface intended to be in physical contact with one or more bearings, and further wherein this layer is supported by a substrate comprising a stiff, lightweight material. The wear resistant layer is attached to the substrate by a coating process. A linear guideway is also provided having a rail made of a lightweight stiff material on which is a hard bearing layer formed by a coating process.

What is claimed is:  
     
         1 . A method of making a rail component for a linear guideway that has at least two rails and a bearing assembly sandwiched between said two rails, said method comprising: 
 (a) providing a substrate material formed in the shape of said rail and having a surface positioned to face said bearing assembly;    (b) permanently depositing a hard wear layer onto said surface through a coating process; and    (c) said substrate being made of a material having a density less than that of a material of which said hard wear layer is made.    
     
     
         2 . A method in accordance with  claim 1  wherein said coating process comprises an HVOF process.  
     
     
         3 . A method in accordance with  claim 1  wherein said coating process comprises an electroplating process.  
     
     
         4 . A method in accordance with  claim 1  wherein said coating process comprises a plasma spray process.  
     
     
         5 . A method in accordance with  claim 1  wherein said hard wear material of step (b) comprises steel.  
     
     
         5 . A method in accordance with  claim 1  wherein said substrate material comprises a composite material.  
     
     
         6 . A method in accordance with  claim 1  wherein said substrate material comprises beryllium.  
     
     
         7 . A method in accordance with  claim 1  wherein said substrate material comprises aluminum.  
     
     
         8 . A method in accordance with  claim 1  wherein said substrate consists essentially of beryllium and aluminum.  
     
     
         9 . A method in accordance with  claim 7  wherein said substrate material further comprises silicon carbide.  
     
     
         10 . A method in accordance with  claim 1  wherein said hard wear material of step (b) comprises tungsten carbide.  
     
     
         11 . A method in accordance with  claim 1  wherein step (b) comprises depositing said hard wear layer onto said surface until said layer has a thickness greater than 15 mils, and then grinding said layer.  
     
     
         12 . A method in accordance with  claim 1  wherein said substrate is made of a material having a specific stiffness at least 1.5 times greater than that of the material of which said hard wear layer is made.  
     
     
         13 . A method in accordance with  claim 5  wherein said composite material comprises at least one metal selected from the group consisting of aluminum, beryllium, magnesium and silicon.  
     
     
         14 . A method of making a linear guideway having a bearing race for containing bearings, comprising: 
 (a) providing first and second rails which are combinable to define a bearing race, each of said first and second rails comprising a substrate having a surface;    (b) permanently depositing a hard wear layer onto said surface of each of said rails by means of a coating process, said hard wear layer having a wear surface defining at least a portion of said bearing race; and    (c) said substrate being made of a material having a density less than that of a material of which said hard wear layer is made.    
     
     
         15 . The method of  claim 14  wherein said substrate material has a specific stiffness at least 50 percent greater than that of said material of said hard wear layer.  
     
     
         16 . The method of  claim 14  wherein said hard wear layer has a thickness greater than 10 mils, and said substrate material comprises at least one material selected from the group consisting of aluminum, beryllium, magnesium and silicon.  
     
     
         17 . A method of making a stage for use in combination with a linear guideway to provide linear motion of said stage, comprising: 
 (a) providing a chassis having at least one rail attached thereto, said rail comprising a substrate having a surface positioned to face and cooperate with a second rail to define a bearing race between said first and second rails when said first and second rails are combined to form the linear guideway;    (b) permanently depositing a hard wear layer onto said surface through a coating process; and    (c) said substrate being made of a material having a density less than that of a material of which said hard wear layer is made.    
     
     
         18 . A method in accordance with  claim 17  wherein said first rail is integrally formed as part of and of the same material as said chassis.  
     
     
         19 . The method of  claim 17  wherein said substrate material has a specific stiffness at least 50 percent greater than that of said material of said layer.  
     
     
         20 . The method of  claim 19  wherein said substrate material has a density no greater than about 60 percent of that of said material of said layer.  
     
     
         21 . A linear guideway, comprising: 
 first and second rails, each of said rails having a bearing surface, said first rail having a hard wear layer which includes said bearing surface, and said first rail having a substrate to which said hard wear layer is attached;    a bearing between said two rails for roller contact with said bearing surfaces;    said substrate being made of a material having a density less than that of a material of which said hard wear layer is made; and    said hard wear layer being formed by permanently depositing a hard wear layer onto said substrate through a coating process.    
     
     
         22 . The linear guideway of  claim 21  wherein said first rail is integrally formed as part of a stage, and said stage is made of the same material as said substrate.  
     
     
         23 . The linear guideway of  claim 21  wherein said substrate material has a specific stiffness at least 1.5 times greater than that of the material of which said hard wear layer is made.  
     
     
         24 . The linear guideway of  claim 21  wherein said hard wear layer has a thickness in the range of 10 to 20 mils, and said substrate material comprises at least one material selected from the group consisting of aluminum, beryllium, magnesium and silicon.  
     
     
         25 . A rail for use as in a linear guideway made in accordance with the method of  claim 1 .  
     
     
         26 . A rail in accordance with  claim 25  wherein said hard wear layer has a thickness greater than 15 mils.  
     
     
         27 . A rail in accordance with  claim 25  wherein said substrate is made of a material having a specific stiffness at least 1.5 times greater than that of the material of which said hard wear layer is made.  
     
     
         28 . A rail in accordance with  claim 25  wherein said composite material comprises at least one metal selected from the group consisting of aluminum, beryllium, magnesium and silicon.  
     
     
         29 . A rail in accordance with  claim 25  wherein said coating process comprises one of the following: HVOF, plasma spray, or electro-plating.