System, method and apparatus for tolerance ring control of slip interface sliding forces

Abstract

A tolerance ring comprising a metallic band for spring features and a complementary low friction material for frictional considerations is disclosed. The tolerance ring is designed to operate within a precisely controlled torque or axial force band to provide a defined amount of resistance and sliding force control between components that move relative to each other. Isolated portions of the tolerance ring form regions of contact with adjacent ones of the components. Other surfaces of the tolerance ring comprise portions with spring features that have geometry suitable for their spring rate, rather than conforming to mating surfaces of the adjacent components.

1 . An assembly, comprising:
 an outer component;   an inner component located in the outer component and movable relative thereto;   a tolerance ring mounted between the inner and outer components, the tolerance ring providing:
 a radial stiffness that is greater than about 20,000 N/mm; 
 an axial sliding force in a range of about 10 to 600 N; and 
 a diameter of at least 10 mm. 
   
     
     
         2 . An assembly according to  claim 1 , wherein the tolerance ring comprises an annular band formed from a metallic material and a low friction material joined to the annular band. 
     
     
         3 . An assembly according to  claim 1 , wherein the tolerance ring has a plurality of projections extending in a radial direction, the projections being compressed between the inner and outer components such that the tolerance ring operates in a flattened portion of a compression/retention force characteristic whereby the projections initially exhibit elastic behavior and are plastically deformed. 
     
     
         4 . An assembly according to  claim 2 , wherein the annular band is formed from spring steel and the low friction material has a coefficient of friction in a range of 0.04 to 0.25, and is laminated to at least one side of the annular band, the annular band has a radial thickness of about 0.1 to 0.7 mm, and the low friction material has a radial thickness in a range of about 0.05 to 0.50 mm. 
     
     
         5 . (canceled) 
     
     
         6 . An assembly according to  claim 3 , wherein the projections also extend in an axial direction as axially-elongated ridges and the tolerance ring also has circumferentially-extending rims at axial ends of the projections. 
     
     
         7 . An assembly according to  claim 6 , wherein the flat sections and circumferentially-extending rims are contiguously formed in a planar configuration, and the axially-elongated ridges have rounded peaks and axial ends of each ridge terminates in a tapered shoulder at the circumferentially-extending rims. 
     
     
         8 . An assembly according to  claim 6 , wherein the projections are circumferentially spaced apart from each other by flat sections. 
     
     
         9 . An assembly according to  claim 6 , wherein the projections circumferentially abut one another. 
     
     
         10 . An assembly, comprising:
 an outer component;   an inner component located in the outer component and movable relative thereto;   a tolerance ring mounted between the inner and outer components, the tolerance ring providing:
 a radial stiffness that is greater than about 20,000 N/mm; and 
 parameters selected from the group consisting of:
 (i) a slip torque in a range of 1 to 25 Nm, and a diameter of less than about 40 mm; 
 (ii) a slip torque in a range of 1 to 100 Nm, and a diameter of more than 40 mm; and 
 (iii) an axial sliding force in a range of 10 to 600 N, and a diameter of more than 10 mm. 
 
   
     
     
         11 . An assembly according to  claim 10 , wherein the tolerance ring comprises an annular band formed from a metallic material and a low friction material joined to the annular band. 
     
     
         12 . An assembly according to  claim 10 , wherein the tolerance ring has a plurality of projections extending in a radial direction, the projections being compressed between the inner and outer components such that the tolerance ring operates in a flattened portion of a compression/retention force characteristic whereby the projections initially exhibit elastic behavior and are plastically deformed, and the tolerance ring provides an overload protection force of less than 100 Nm. 
     
     
         13 . An assembly according to  claim 10 , wherein the tolerance ring is greater than 65 mm in diameter. 
     
     
         14 . An assembly according to  claim 11 , wherein the annular band is formed from spring steel and the low friction material has a coefficient of friction in a range of 0.04 to 0.25, and is laminated to one side of the annular band, the annular band has a radial thickness of about 0.1 to 0.7 mm, and the low friction material has a radial thickness in a range of about 0.05 to 0.50 mm. 
     
     
         15 . (canceled) 
     
     
         16 . An assembly according to  claim 12 , wherein the projections extend in an axial direction as axially-elongated ridges and are circumferentially spaced apart from each other by flat sections, the tolerance ring also having circumferentially-extending rims at axial ends of the projections. 
     
     
         17 . (canceled) 
     
     
         18 . A tolerance ring assembly, comprising:
 an outer component having a bore with an axis therein;   an inner component mounted in the bore of the outer component, such that the inner component mates with the outer component and is movable relative thereto; and   a tolerance ring located in the bore between the inner and outer components, the tolerance ring comprising an annular band formed from a metallic material and a low friction material joined to the annular band, the tolerance ring also having a plurality of projections extending relative to the axis, the projections being compressed between the inner and outer components such that the tolerance ring operates in a flattened portion of a compression/retention force characteristic whereby the projections initially exhibit elastic behavior and are plastically deformed, and the tolerance ring provides an overload protection force of less than 100 Nm.   
     
     
         19 . A tolerance ring assembly according to  claim 18 , wherein the tolerance ring is greater than 65 mm in diameter. 
     
     
         20 . A tolerance ring assembly according to  claim 18 , wherein the overload protection force is less than 25 Nm, and the tolerance ring is less than 40 mm in diameter. 
     
     
         21 . A tolerance ring assembly according to  claim 18 , wherein the annular band is formed from spring steel and the low friction material has a coefficient of friction in a range of 0.04 to 0.25, and is laminated to one side of the annular band, the annular band has a radial thickness of about 0.1 to 0.7 mm, and the low friction material has a radial thickness in a range of about 0.05 to 0.50 mm. 
     
     
         22 . (canceled) 
     
     
         23 . A tolerance ring assembly according to  claim 18 , wherein a low resistance to axial sliding in a range of about 10 and 600 N is provided, and the tolerance ring has a diameter of at least 10 mm. 
     
     
         24 . A tolerance ring assembly according to  claim 18 , wherein the overload protection force comprises a torque overload protection force of between 1 to 25 Nm, and the tolerance ring has a diameter of less than 40 mm. 
     
     
         25 . A tolerance ring assembly according to  claim 18 , wherein the projections extend in an axial direction as axially-elongated ridges and are circumferentially spaced apart from each other by flat sections, the tolerance ring also having circumferentially-extending rims at axial ends of the projections, the flat sections and circumferentially-extending rims are contiguously formed in a planar configuration. 
     
     
         26 . (canceled) 
     
     
         27 . A tolerance ring assembly according to  claim 25 , wherein the axially-elongated ridges have rounded peaks and axial ends of each ridge terminates in a tapered shoulder at the circumferentially-extending rims. 
     
     
         28 . A tolerance ring assembly according to  claim 18 , further comprising a corrosion resistant layer on the annular band, the corrosion resistant layer has a thickness of about 1 to 50 microns, the corrosion resistant layer comprises an epoxy resin layer. 
     
     
         29 . (canceled) 
     
     
         30 . (canceled) 
     
     
         31 . A tolerance ring assembly according to  claim 28 , wherein the corrosion resistant layer further comprises an adhesion promoter layer underlying the epoxy resin layer. 
     
     
         32 . (canceled) 
     
     
         33 . (canceled) 
     
     
         34 . A tolerance ring assembly according to  claim 28 , wherein the epoxy resin layer comprises a hardening agent. 
     
     
         35 . (canceled)