Backing assembly for use in z-mill type rolling mills

Abstract

A backing assembly for a Z-mill includes an elongated backing shaft having a number of longitudinally spaced bearing support surfaces configured to rotatably support cylindrical roller bearings thereon. The backing shaft is rotatably secured to a Z-mill housing by saddle assemblies which support the backing shaft in vertical movement along a generally eccentric path. A series of lubricant feed channels are formed along the interior of the shaft, and permit the flow of bearing lubricating fluid to each bearing support surface. The lubricant supply assembly is provided to supply an air/oil lubricating fluid mixture under pressure into the feed channels. The lubricant supply channel includes a supply manifold having internal valving to regulate the volume and timing of gas and oil flow therethrough, and a bearing plate having lubricant outlet ports. The bearing plate is resiliently biased into juxtaposed abutting contact with channel inlets formed in an end of the backing shaft, with the outlet ports and channel inlets having complementary shapes selected to maintain at least partial fluidic contact therebetween, as the end of the backing shaft moves eccentrically.

1 . A backing assembly for a Z-mill type rolling mill, the assembly comprising,
 a backing shaft being elongated in a longitudinal direction along a shaft axis and extending from a first shaft end to a second shaft end, the backing shaft defining a plurality of longitudinally spaced cylindrical bearing mounting surfaces, and further including a plurality of lubricant feed channels extending axially through said shaft, each of said feed channels providing fluid communication between an associated channel inlet open to said first shaft end and a respective lubricant outlet orifice disposed in an associated one of said bearing mounting surfaces,   a plurality of bearings, each of the bearings including a cylindrical bore having a radial diameter selected marginally greater than a radial diameter of the bearing mounting surfaces, each said bearing being mounted on a respective bearing mounting surface so as to be rotatable thereon relative to said backing shaft,   a saddle assembly for supporting said shaft in rotational movement with said first shaft end being movable along a generally eccentric path, the saddle assembly including at least one saddle bearing surface engaging said backing shaft at a location spaced from said bearing mounting surfaces,   a lubricant supply assembly for supplying a lubricant under pressure to each said channel inlet as said first shaft end moves along said eccentric path, said supply assembly including a fluid flow assembly and a bearing member, the bearing member having an end face configured for juxtaposed contact with at least part of said backing shaft first end, the bearing member being movable in a generally axial direction between a first position where said end face is moved into substantially juxtaposed contact with said at least part of said backing shaft first end, and a second position spaced rearwardly therefrom,   a biasing member for resiliently biasing the bearing member to the first position,   the fluid flow assembly providing fluid communication between at least one fluid supply and a lubricant outlet port disposed in said bearing surface, the outlet port being positioned for at least partial fluid communication with at least one feed channel inlet when the bearing member is moved to the first position.   
     
     
         2 . The backing assembly as claimed in  claim 1  wherein said outlet port comprises a plurality of arrays of feed openings disposed in said end face, said arrays being positioned to maintain fluid communication between at least one feed opening and each of the channel inlets as the first shaft end moves along the eccentric path. 
     
     
         3 . The backing assembly as claimed in  claim 1  wherein the outlet port is selected from the group consisting of an array of a plurality of feed holes and an elongate recess. 
     
     
         4 . The backing assembly as claimed in  claim 1  wherein said lubricant supply assembly includes a manifold housing having a valve assembly, and at least one injector tube in communication with each of said valve assembly and the outlet ports, the fluid flow assembly further comprising,
 a gas supply conduit providing fluid communication between a pressurized gas source and said valve assembly, and   an oil supply conduit providing fluid communication between an oil source and said valve assembly,   and wherein the valve assembly is operable for regulating the flow rate of said gas and said oil into each said injector tube.   
     
     
         5 . The backing assembly as claimed in  claim 4  wherein said outlet port includes a plurality of feed openings in said end face, the feed openings being in fluid communication with each of the injector tubes. 
     
     
         6 . The backing assembly as claimed in  claim 5  wherein said bearing member includes an injector chamber, the injector chamber being movable relative to the injector tube and being provided in fluid communication therewith, as the bearing member is moved between the first and second positions. 
     
     
         7 . The backing assembly as claimed in  claim 2  wherein at least one of the bearing member and the backing shaft first end includes,
 a rotary seal extending radially about the outlet port, when the bearing member is moved to the first position, the rotary seal engaging the other of the bearing member and the backing shaft first end to substantially prevent the flow of said lubricant therebetween.   
     
     
         8 . The backing assembly as claimed in  claim 1  wherein said lubricant comprises a mixture of air and oil droplets having an average droplet size of between about 0.01 and 0.05 mm, and said lubricant supply assembly operable to supply said lubricant to each of said lubricant feed channels at a pressure selected at between about 2 and 30 psi. 
     
     
         9 . The backing assembly as claimed in  claim 1  wherein each of said lubricant feed channels comprise a discrete fluid channel having a radial diameter selected at between about 0.25 and 0.75 cm,
 wherein the channel inlets of a first pair of said feed channels comprising generally arcuate recesses extending radially a first distance about the shaft axis; and   the channel inlets of a second other pair of said feed channels comprising generally arcuate recesses extending radially a second distance about the shaft axis.   
     
     
         10 . A backing assembly for a rolling mill comprising,
 a backing shaft being elongated in a longitudinal direction along a shaft axis, and extending from a first shaft end to a second shaft end,   the backing shaft defining a plurality of longitudinally spaced cylindrical bearing mounting surfaces, and further including a plurality of lubricant feed channels extending axially along an interior portion of said shaft, each of said lubricant feed channels providing fluid communication between an associated channel inlet open to said first shaft end and a channel outlet disposed in a respective one of said bearing mounting surfaces,   an associated cylindrical roller bearing rotatably mounted on each of said bearing mounting surface,   a saddle assembly rotatably supporting said first shaft end in movement along a generally eccentric path, the saddle assembly including at least one saddle bearing surface engaging said backing shaft intermediate an adjacent pair of said bearing mounting surfaces,   the first shaft end further including a seating surface extending annularly about said channel inlets,   a lubricant supply assembly for supplying a lubricant fluid under pressure to each said channel inlet,   said lubricant supply assembly including a bearing plate having a lubricant fluid outlet port and a fluid flow assembly, the fluid flow assembly providing fluid communication between at least one fluid supply and an outlet port formed in said bearing plate, the bearing plate being movable in a generally axial direction into juxtaposed contact with the first shaft end to provide at least partial fluid communication between the outlet port and the channel inlets,   an annular seal member disposed on said bearing plate and extending radially about said outlet port, the seal member being movable together with the bearing plate into sealing contact with said seating surface to substantially prevent the movement of lubricant fluid therebetween as said backing shaft is rotated.   
     
     
         11 . The backing assembly as claimed in  claim 10  wherein each associated cylindrical bearing includes a cylindrical through bore having a radial diameter marginally greater than a radial diameter of the bearing mounting surface, the channel outlet of each feed channel including a plurality of longitudinally spaced grooves extending radially about said shaft and which are open to the through bore of the associated bearing. 
     
     
         12 . The bearing assembly as claimed in  claim 10  including at least four of said lubricant feed channels,
 the channel inlets of a first pair of said feed channels comprising first opposed generally arcuate recesses extending radially and being spaced a first distance about the shaft axis; and   the channel inlets of a second other pair of said feed channels comprising second opposed generally arcuate recesses extending radially and being spaced a second distance about the shaft axis.   
     
     
         13 . The backing assembly as claimed in  claim 12  wherein each of the first and second arcuate recesses extend radially about the shaft axis along an arc selected at between about 90 and 175°. 
     
     
         14 . The backing assembly as claimed in  claim 12  wherein the outlet port comprises two opposing pairs of feed hole arrays, each feed hole array being provided in said bearing plate in a position selected to maintain fluid communication between each of said feed channel inlets and at least two feed holes, as the first shaft end moves along said eccentric path. 
     
     
         15 . The backing assembly as claimed in  claim 14  wherein said bearing plate is fixed against rotation relative to a rolling mill housing, and the lubricant fluid comprising a gas/oil mixture comprising between about 97 and 99% by volume gas and about 3 and 1% by volume oil droplets. 
     
     
         16 . The backing assembly as claimed in  claim 15  wherein the annular seating surface comprises a generally flat surface extending normal to said shaft axis, said annular seating surface having a radial width greater than the difference between the major axis and the minor axis of the elliptical path. 
     
     
         17 . The backing assembly as claimed in  claim 10  wherein the bearing plate is axially displaceable between a sealing position wherein said annular seal member engages and is provided in substantially fluid sealing contact with said seating surface, and a non-sealing position moved axially therefrom, the backing assembly further including a biasing member for resiliently biasing the bearing plate towards the sealing position. 
     
     
         18 . The backing assembly as claimed in  claim 17  wherein said lubricant fluid comprises a mixture of air and high viscosity oil droplets having an average droplet size of between about 0.005 and 0.1 mm, and said lubricant supply assembly is operable to supply said lubricant along each of said fluid feed channels at a pressure selected at between about 2 and 30 psi, at an oil flow rate of less than about 2 cm 3 /hour. 
     
     
         19 . The backing assembly as claimed in  claim 18  wherein each of said lubricant feed channels comprise a discrete fluid channel having a radial diameter selected at between about 0.4 and 0.75 cm. 
     
     
         20 . A Z-mill type rolling mill comprising,
 a housing,   a plurality of backing shafts mounted in said housing, each of said backing shafts being elongated along a longitudinal axis and extending from a first shaft end to a second shaft end, and defining at least two longitudinally spaced cylindrical bearing mounting surfaces, a plurality of lubricant feed channels extending axially along a portion of said shaft, said feed channels providing fluid communication between an associated inlet open to said first shaft end and a lubricant outlet disposed in a respective one of said bearing mounting surfaces, the first shaft end including a generally flat seating surface extending as an annular surface about said feed channel inlets generally normal to said shaft axis,   an associated cylindrical bearing rotatably mounted on each of said bearing mounting surface,   a plurality of saddle assemblies rotatably supporting said shaft in said housing with said first shaft end being movable along a generally eccentric path, each saddle assembly including at least one saddle bearing surface engaging said backing shaft,   a manifold fixed against rotation relative to said housing and for regulating the supply of a lubricant fluid under pressure to each said associated channel inlet,   a bearing member provided for juxtaposed contact with the first shaft end, the bearing member including a bearing plate having a plurality of outlet feed holes formed therein, the manifold being in fluid communication with a fluid supply and the outlet feed holes disposed in said bearing member,   the bearing member being movable in a generally axial direction between a sealing position wherein the bearing plate is moved into juxtaposed contact with at least part of said first shaft end to fluidically communicate the at least one of the feed holes with a selected feed channel inlet so as to permit the flow of said lubricant therein, and a second position moved a distance therefrom,   an annular seal member disposed on said bearing plate radially about said feed holes, the bearing plate being axially displaceable between a sealing position wherein said annular sealing member is in sealing contact with a biasing member, for resiliently biasing the bearing plate towards the sealing position, and   wherein the lubricant fluid comprises a mixture of air and high viscosity oil.   
     
     
         21 . The rolling mill as claimed in  claim 20  wherein the bearing plate is substantially fixed against rotation relative to said housing with the outlet feed holes provided as a plurality of arrays of at least three discrete feed holes,
 wherein each of the channel inlets of a first pair of said feed channels comprising opposed generally arcuate recesses extending radially and being spaced a first distance about the shaft axis; and   each of the channel inlets of a second other pair of said feed channels comprising second opposed generally arcuate recesses extending radially and being spaced a second distance about the shaft axis.