Abstract:
A bearing chocking assembly for mill rolls includes an axially immovable segmented inner ring engageable with a formation such as a shoulder in an annular groove formed on a mill roll neck, and an axially movable outer ring engageable with a bearing retainer for axially positioning the bearing retainer to &#34;chock&#34; or axially position bearings which journal the roll neck. Cooperating wedge-shaped cam surfaces on the inner and outer rings effect axial movement of the outer ring when the outer ring is rotated relative to the inner ring. The inner ring is keyed to the roll neck to prevent relative rotation therebetween. The outer ring is bolted to the inner ring once it has been positioned to properly chock the roll bearings.

Description:
This is a division, of application Ser. No. 393,507, filed Aug. 31, 1973 now Pat. No. 3,912,345. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a novel and improved assembly for axially positioning or &#34;chocking&#34; mill roll bearings and the like where such bearings must frequently be chocked, adjusted and unchocked to permit roll replacement and to assure maximum roll operating life. 
     2. Prior Art 
     Rolling mills include an array of parallel extending rolls which exert compressive rolling forces on metal feed stock, typically forming it into thinner elongated strip or plate configurations. The mill rolls have reduced diameter end regions called roll necks which are journaled for rotation by roller bearings supported in a mill stand. Adjustable bearing chocking devices hold the roller bearings in place and provide a means for axially adjusting bearing play. 
     The mill rolls, particularly the primary work rolls, must frequently be removed and reground. In some present day cold rolling mills, the work rolls have a useful life of only about 4 to 8 hours. In order to minimize mill down-time during roll replacement, it is desirable to provide a bearing chocking device which is easily installed, removed, and adjusted to effect proper chocking of the roller bearings. It is also desirable to provide a bearing chocking device which, for purposes of safety, minimizes the possibility of its becoming disengaged or loosening its pre-adjusted chocking position during operation. 
     Most known bearing chocking devices for mill rolls have included three annular components: a locking collar assembly which mounts in an annular groove on a roll neck, and a pair of rings threaded together to provide an annular assembly of adjustable length. The assembly of threaded rings is positioned between the locking collar and the bearing to be chocked, whereafter the rings are rotated to extend the length of the assembly until the bearing is properly chocked. 
     Known locking collar assemblies are either relatively complex, requiring substantial amounts of time to install and remove, or are relatively insecure and present safety concerns. One recently proposed locking collar provides two semi-annular members hinged together by a single hinge pin at one end and releasably coupled by a single threaded fastener at the other end. If either the hinge pin or the threaded fastener should fail, the collar drops off the mill neck. 
     Known threaded ring assemblies are expensive-to-machine structures that are not easily installed, removed and adjusted. Recent proposals to improve the configuration of these assemblies have called for additional modification of other surrounding structures such as the bearing retaining rings. Some proposals even require modification of the roll neck configuration. These modifications are expensive to effect and result in specially configured parts that cannot be used with standard bearing chocking devices. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the foregoing and other drawbacks of the prior art and provides a novel and improved bearing chocking system for mill rolls which requires no modification of most existing mill roll necks or other associated parts, which eliminates the need for separate locking collars and threaded ring assemblies together with their expense and safety concerns, and which provides a vastly safer easily installed, adjusted, and removed bearing chock. 
     In accordance with the present invention, a novel bearing chocking assembly includes a segmented inner ring which is received in a standard annular groove in a conventional roll neck. An outer ring is provided which can be slipped over the inner ring segments and into engagement with a conventional bearing retainer. Wedge-shaped cam surfaces on the inner ring segments and the outer ring coact to axially move the outer ring as it is rotated relative to the inner ring, thereby axially adjusting the position of the bearing retainer and effecting chocking of the bearings. The inner ring is keyed to the roll neck to prevent relative rotation therebetween. The outer ring is bolted to the inner ring once the outer ring has been positioned to properly chock the roll bearings. 
     In one embodiment, the segmented inner ring includes two substantially identical semi-annular ring segments. Adjacent end regions of the segments are provided with locating holes to temporarily receive the pins of a locating tool. The locating tool is designed to hold the ring segments together in engagement with the roll neck groove while the outer ring is being installed or removed. 
     In another embodiment, the inner ring includes a pair of semi-annular segments which are hinged together. The hinged connection between the segments permits the segments to be installed over the roll neck and to extend into the groove, and also helps to retain the segments in position during installation and removal of the outer ring. 
     In both embodiments, the inner ring segments are keyed to the roll neck to prevent relative rotation therebetween when the outer ring is rotated relative to the inner ring. Threaded fasteners extending through aligned apertures in the inner and outer rings secure the inner and outer rings together once the outer ring has been positioned to properly chock the roll bearings. 
     A significant feature of the bearing chocking device of the present invention is its extremely simple construction. It uses no auxiliary locking ring which can fail and fall of the roll neck. It requires no extensive mating threaded connections to provide axial adjustability. 
     Another feature is the ease with which the improved bearing chocking device can be installed and removed. Once the threaded fasteners which connect the inner and outer rings together have been removed, disassembly involves nothing more than rotating the outer ring to a position where it is free to pass over the inner ring, whereafter the outer ring is removed and the inner ring segments are lifted off the roll neck. Reassembly reverses these steps. A specially configured wrench engageable with spaced notches around the periphery of the outer ring makes it easy to rotate the outer ring for proper bearing chocking. 
     Still another feature of the present invention is its inherent failure-free design which assures safe, reliable operation. The outer ring surrounds the inner ring segments preventing their moving out of the shaft groove. The outer ring cannot rotate relative to the inner ring segments so long as even one of the several threaded fasteners which secure these rings together remains in tact. 
     In following from the foregoing discussion, it will be apparent that a principal object of this invention is to provide a novel and improved bearing chocking device. 
     Other objects and a fuller understanding of the invention may be had by referring to the following description and claims taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view showing a mill roll end region supported in the mill stand of a steel rolling mill; 
     FIG. 2 is an enlarged sectional view similar to FIG. 1, showing another portion of the mill roll of FIG. 1 together with a novel bearing chocking assembly; 
     FIG. 3 is a front elevational view of the bearing chocking assembly during installation immediately after the outer ring of the bearing chocking assembly has passed over the inner ring thereof; 
     FIG. 4 is a sectional view of the inner and outer rings assembled in a bearing chocking position prior to their being secured together by threaded fasteners; 
     FIG. 5 is a front elevational view of the inner locking ring of the bearing chocking assembly; 
     FIG. 6 is a top plan view as seen from the plane indicated by the line 6--6 in FIG. 5; 
     FIG. 7 is an enlarged side elevational view of a portion of the inner ring as seen from the plane indicated by the line 7--7 in FIG. 5; 
     FIG. 8 is a front elevational view of the outer ring of the bearing chocking assembly; 
     FIG. 9 is a cross-sectional view as seen from the plane indicated by the line 9--9 in FIG. 8; 
     FIG. 10 and 11 are top plan and side elevational views, respectively of a locating tool used to temporarily retain the inner ring segments in place during installation of the outer ring; 
     FIGS. 12 and 13 are top plan and side elevational views of a retaining key; 
     FIG. 14 is a side elevational view of a special wrench for rotating the outer ring relative to the inner ring; 
     FIG. 15 is an enlarged side elevational view of a portion of the bearing chocking assembly illustrating the wire-tired threaded fasteners which secure the inner and outer ringe together; 
     FIG. 16 is a cross-sectional assembly view of another steel mill working roll together with a second bearing chocking assembly embodiment; 
     FIG. 17 is a front elevational view of the second bearing chocking assembly; 
     FIG. 18 is an enlarged front elevational view of the inner ring of the second bearing chocking assembly; 
     FIG. 19 is a top plan view as seen from the plane indicated by the line 19--19 in FIG. 18; 
     FIG. 20 is an enlarged view of the portion of the inner ring of FIG. 18; 
     FIG. 21 is a side elevational view of the structure shown in FIG. 22, as seen from the plane indicated by the line 21--21 in FIG. 18; 
     FIG. 22 is a front elevational view of the outer ring of the second bearing chocking assembly; and, 
     FIG. 23 is a cross-sectional view as seen from the plane indicated by the line 23--23 in FIG. 22. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a mill roll of the type used in hot strip steel rolling mills is illustrated generally at 10. The roll 10 is of conventional configuration including a generally cylindrical central rolling surface 11 with identical reduced diameter necks formed on opposite end regions, one of which is shown at 12. Each of the roll necks is journaled for rotation by a pair of roller bearings 13, 14 supported in a conventional mill stand assembly, indicated generally by the numeral 15. 
     The bearings 13, 14 are positioned side-by-side and cooperate to support the mill roll 10. The bearings 13, 14 have inner races 13a, 14a and outer races 13b, 14b with rollers 13c, 14c interposed therebetween. A bore 16 terminated by a shoulder 17 is formed in the mill stand 15 and receives the outer races 13b, 14b. A clamping ring 18 secured by threaded fasteners 19 to the mill stand 15 engages the outer race 14b and clamps the bearings 13, 14 in side-by-side engagement with the outer race 13b contacting the shoulder 17. 
     A cylindrical supporting surface 20 is provided on the roll neck 12 between an annular shoulder 21 and an annular groove 22. The inner races 13a, 14a are located on the supporting surface 20 with the inner race 13a contacting the shoulder 21. A bearing retaining ring 23 is positioned on the supporting sruface 20 between the inner race 14a and the groove 22. An oil seal 24 is interposed between the bearing retaining ring 23 and the clamping ring 18 to prevent the escape and contamination of bearing lubricant. 
     In accordance with the present invention, an improved bearing chocking assembly, indicated generally by the numeral 30, is provided for axially positioning the bearing retaining ring 23 to adjust the chocking of the bearings 13, 14. The chocking assembly 30 includes an inner ring assembly 31 positioned in the annular groove 22, and an outer ring 32 which bears against the retaining ring 23. As will be explained in greater detail, the inner and outer rings 31, 32 carry cooperating wedge-shaped cam formations which effect axial movement of the outer ring 32 relative to the inner ring 31 when the outer ring is rotated relative to the inner ring. Bearing chocking is adjusted by turning the outer ring 32 until the bearings are clamped tightly between the shoulder 21 and the retaining ring 23, whereafter the outer ring 32 is loosened to give the bearings 13, 14 proper freedom of movement. 
     Keyways are formed on opposite sides of the roll necks 12, as illustrated at 12a, 12b in FIG. 2. As will be explained in greater detail, a specially configured locating tool 50 is positioned in the keyway 12a during installation of the bearing chocking assembly 30 to hold segments of the inner ring assembly 31 in place. A specially configured retaining key 51 is positioned in the keyway 12b and extends into a notch in the inner ring assembly 31 and the roll 10. A mating keyway 23a formed in the retaining ring 23 receives portions of the key 51 to establish a driving connection between the retaining ring 23 and the roll 10. 
     Referring to FIGS. 10 and 11, the locating tool 50 includes a bar-shaped handle 50a of generally rectangular cross-section. A gripping aperture 50b is formed through one end region of the handle 50a. The opposite end region is apertured to rigidly mount two spaced parallel extending locating pins 50c, 50d. 
     Referring to FIGS. 12 and 13, the retaining key 51 comprises a bar of generally rectangular cross section. One end region of the key 51 is rounded at 51a. The outer end region is notched at 51b to define a projection 51c of reduced rectangular cross section. 
     The construction of the inner ring assembly 31 is illustrated in FIGS. 5 and 6. Two identical semi-annular segments 40, 41 are provided with radially outwardly extending flanges 42, 43. The flanges 42, 43 are of wedge-shaped configuration, as best seen in FIG. 6. Cam surfaces 42a, 43a are formed on the back sides of the flanges 42, 43. Apertures 44, 45 are formed through the flanges 42, 43. 
     Referring to FIG. 2 in conjunction with FIGS. 5-7, end regions of the inner ring segments 40, 41 are adapted to receive the locating tool 50 and the retaining key 51. The end regions of the segments 40, 41 are drilled to provide locating holes 46, 47 adapted to receive the locating pins 50c, 50d. As is best seen in FIGS. 6 and 7, the locating holes 46, 47 are of T-shape, defining a port 46a, 47a of entry into which the locating pins 50c, 50d can be inserted and two relief ports 46b, 47b to prevent accumulation of foreign matter in the chamber defined by port 46a, 47a. The end regions of the segments 40, 41 are also notched at 48, 49 to receive the retaining key end projection 51c. 
     The construction of the outer ring 32 is illustrated in FIGS. 8 and 9. Two radially inwardly extending flanges 62, 63 of wedge-shaped configuration define cam surfaces 62a, 63a on their front sides. Threaded apertures 64, 65 are formed through the flanges 62, 63. Notches 66 formed at 45° spacings around the periphery of the outer ring 32 are adapted to receive a special wrench 55, as shown in FIG. 3, to tighten and loosen the chocking of the bearings 13, 14. 
     Referring to FIG. 14, the wrench 55 includes a bar-shaped handle 55a of generally rectangular cross section drilled at one end to provide a gripping aperture 55b. The opposite end region has an enlarged neck 55c adapted to be received in the notches 66. Opposed projections 55d, 55e are provided to grip portions of the outer ring adjacent the notches 66, as shown in FIG. 3. 
     Installation of the bearing chocking assembly 30 on the roll neck 12 is quite simple. The inner ring segments 40, 41 are positioned in place in the annular groove 22 with the notches 48, 49 receiving the retaining key end projections 51c. The locating tools 50 are then positioned in the keyways 12a with the locating pins 50c, 50d extending into the locating holes 46, 47, as shown in FIG. 2. The locating tools 50 serve to retain the inner ring segments 40, 41 in place until the outer ring 32 is brought into position. The outer ring is slipped over the inner ring segments with the inwardly extending flanges 62, 63 positioned between the outwardly extending flanges 42, 43, as shown in FIG. 3. 
     Once the outer ring flanges 62, 63 have passed inwardly of the inner ring flanges 42, 43 the wrench 55 is positioned in one of the notches 66 and the outer ring is rotated to bring the cam surfaces 42a, 62a and 43a, 63a into engagement as shown in FIG. 2. Rotation of the outer ring is continued until the bearing retainer ring 23 firmly clamps the bearings 13, 14 against the shoulder 21. The outer ring is then backed-off a predetermined distance, typically about 15°, to provide a proper freedom of movement for the bearings 13, 14. The inner and outer ring apertures 44, 64 and 45, 64 are then aligned, as shown in FIG. 4, to receive threaded fasteners 75 as shown in FIG. 1. Once the fasteners 75 have been tightened in place, they are wired as shown in FIG. 15 to prevent their subsequent loosening. The locating tool 50 and the wrench 55 are then removed from the inner and outer rings 31, 32 and stored for subsequent use. 
     Removal of the bearing chocking assembly 30 is accomplished simply by reversing the described installation steps. 
     The foregoing description is directed to mill rolls of the type commonly used in steel hot strip rolling mills. The bearing chocking assembly of the present invention is, by no means, limited to use on hot strip mills, as will now be illustrated in conjunction with a plate rolling mill installation utilizing a slightly modified embodiment of the bearing chocking assembly. 
     Referring to FIG. 16, a mill roll of the type used in steel plate rolling mills is illustrated generally at 110. The roll 110 has a reduced diameter neck 112 supported by bearings (not shown) in a mill stand 115. The neck 112 is provided with a keyway 112b, and has an annular groove 122. A bearing retaining ring 123 is positioned on the roll neck 112 and has a keyway 123a overlying the roll neck. A retaining key 151 positioned in the keyways 112b, 123b establishes a driving connection between the roll 110 and the retaining ring 123. The retaining key 151 has a reduced cross section end projection 151c extending across the annular groove 122. 
     A bearing chocking assembly 130 is provided including an inner ring assembly 131 positioned in the annular groove 122, and an outer ring 132 engaging the retaining ring 123. The chocking assembly embodiment 130 differs from the above-described chocking assembly 30 in three respects: (1) the segments of the inner ring assembly 131 are hinged together to obviate the need for a locating tool during installation; (2) the locking bolts used to prevent relative rotation between the inner and outer rings extend completely through the outer ring and are threaded into apertures in the retaining ring 123 rather than into apertures in the outer ring; and (3) only one retaining key is employed to key the inner ring to the roll neck. 
     The construction of the inner ring assembly 131 is shown in FIGS. 18-21. A pair of semi-arcuate segments 140, 141 are provided with radially outwardly extending flanges 142, 143. The flanges 142, 143 are of wedge-shaped configuration, as best seen in FIG. 19. Cam surfaces 142a, 143a are formed on the back sides of the flanges 142, 143. Apertures 144, 145 are formed through the flanges 142, 143. 
     A hinge assembly 190 is provided to pivotally connect adjacent end regions of the rings 140, 141. As best seen in FIGS. 20, 21 the hinged end regions of the segments 140, 141 are notched at 192, 193 respectively to receive a hinge bar 194. A pair of roll pins 195 driven into aligned through apertures in the ring segment 141 and the hinge bar 194 rigidly couple the hinge bar 194 to the ring segment 141. A single roll pin 196 positioned in aligned apertures in the ring segment 140 and the hinge bar 194 pivotally connect the hinge bar 194 to the ring segment 140. By this arrangement, the ring segments 140, 141 can pivot relative to each other for installation over the end of the mill roll 110 and into the annular groove 122. The opposite ends of the inner ring segments 140, 141 terminate in spaced relationship with each other to define a gap 148 of such width as will receive the retaining key end projection 151c when the inner ring assembly 13 is positioned in the annular groove 122. 
     The construction of the outer ring 132 is illustrated in FIGS. 22, 23. Two radially inwardly extending flanges 162, 163 of wedge-shaped configuration define cam surfaces 162a, 163a on their front sides. Apertures 164, 165 are formed through the flanges 162, 163. Notches 166 formed at spaced intervals around the periphery of the outer ring 132 are adapted to receive the ring rotating wrench 55. 
     Installation of the bearing chocking assembly 130 on the roll neck 112 is identical to that described in conjunction with the bearing chocking embodiment 30, with two minor exceptions. First, in positioning the inner ring segments, the ring gap 148 is aligned in mating relationship with the retaining key end projection 151c and no locating tool is needed to keep the inner ring segments in position. Secondly, the ring locking fasteners 175 extend through aligned apertures 144, 165 in the inner and outer rings 131, 132 and into threaded apertures 199 formed in the retaining ring 123. By this arrangement, the threaded fasteners assist the key 151 in establishing a driving connection between the roll neck 112 and the bearing chocking assembly 130. 
     Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.