Abstract:
A hose reel bearing arrangement supports a rotatable swivel shaft on a stationary hose reel frame. The bearing arrangement comprises a stationary bearing race, a rotating bearing race and a bearing. The stationary bearing race is anchored to the stationary hose reel frame, and has a stationary arcuate land for bearing an axial load, a stationary cylindrical land for bearing a radial load, and a stationary frustoconical intervening portion. The rotating bearing race is anchored to the rotatable swivel shaft, and has a rotating arcuate land for bearing the axial load, a rotating cylindrical land for bearing the radial load, and a rotating frustoconical intervening portion. The bearing is bracketed axially by the stationary arcuate land and the rotating arcuate land, and radially by the stationary cylindrical land and the rotating cylindrical land.

Description:
BACKGROUND 
       [0001]    The present invention relates generally to inlet swivels for hose reels. More particularly, the present invention relates to bearing arrangements for swivels capable of transmitting high-pressure fluids while also minimizing pressure drop. 
         [0002]    Hose reels are commonly used in fluid handling industries, such as for the dispensing of pressurized air, lubricants, adhesives and the like. In these and other applications, bulk quantities of the pressurized fluid are distributed in much smaller volumes using a dispenser that is separated from a storage vessel via a hose. Lengthy hoses are used to facilitate wide ranging of the dispenser to many different distribution points. Hose reels are used to conveniently wind and un-wind the hose, thereby reducing the potential for damaging the hose or people tripping over the hose. 
         [0003]    Typical hose reels utilize a swivel that is positioned at the axis of rotation of the reel. An inlet end of the swivel receives fluid from the bulk container, and delivers the fluid to a stationary frame of the hose reel assembly. A rotating end of the swivel receives fluid from the inlet end, and allows the hose to rotate with a drum of the hose reel assembly. The swivel is subject to axial loading from pressurized fluid flowing through the swivel and radial loading from the weight of the drum and hose. In order to withstand or eliminate the axial loading, typical high-pressure swivel couplings utilize a “balanced seal” design. In a typical balanced seal design, a non-rotating post having transfer holes, or perforations, can be joined to a sleeve that rotates about the post, forming a fluid path from the inside of the post, through the perforations and into the sleeve. Such a swivel is described in U.S. Pat. No. 5,052,432. The transfer holes, however, introduce a constriction into the fluid passage that generates an undesirable pressure drop and that also result in stress concentrations that limit the pressure rating of the swivel. 
       SUMMARY 
       [0004]    A hose reel bearing arrangement supports a rotatable swivel shaft on a stationary hose reel frame. The bearing arrangement comprises a stationary bearing race, a rotating bearing race and a bearing. The stationary bearing race is anchored to the stationary hose reel frame, and has a stationary arcuate land for bearing an axial load, a stationary cylindrical land for bearing a radial load, and a stationary frustoconical intervening portion. The rotating bearing race is anchored to the rotatable swivel shaft, and has a rotating arcuate land for bearing the axial load, a rotating cylindrical land for bearing the radial load, and a rotating frustoconical intervening portion. The bearing is bracketed axially by the stationary arcuate land and the rotating arcuate land, and radially by the stationary cylindrical land and the rotating cylindrical land. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a perspective view of a hose reel having a high pressure swivel connecting a frame to a spool. 
           [0006]      FIG. 2  is a cross-sectional view of the hose reel of  FIG. 1  showing a high pressure swivel having an inlet housing and an outlet housing connected by a swivel shaft. 
           [0007]      FIG. 3  is a close-up cross-sectional view of the hose reel swivel of  FIG. 2  showing inner and outer bearing races surrounding the swivel shaft. 
           [0008]      FIG. 4  is a close-up cross-sectional view of a ball bearing positioned between the inner and outer bearing races of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]      FIG. 1  is a perspective view of hose reel  10  having high pressure swivel  12  connecting frame  14  to spool  16 . Frame  14  includes base  18  to which are connected sidewalls  20 A and  20 B. Spool  16  includes drum  22  and disks  24 A and  24 B. Swivel  12  includes a bearing structure that rotatably couples sidewall  20 A with disk  24 A. A similar bearing structure (bearing  26  of  FIG. 2 ) rotatably couples sidewall  20 B with disk  24 B. However, swivel  12  provides a fluid coupling between the exterior of frame  14  and the interior of spool  16  so that a hose can be wound around drum  22 . 
         [0010]    Frame  14  provides a mounting structure upon which spool  16  can be rotated. Thus, frame  14  remains stationary as hose reel  10  is operated. Spool  16  rotates on swivel  12  and bearing  26 , which extend through the axis of rotation of drum  22 , axis A. As spool  16  rotates, a hose can be wound or un-wound from drum  22 . A hose (or tubing, conduit or the like) may be wound around drum  22  through window  28 , which is lined by rollers  30 A- 30 D to prevent damage to the hose. Swivel  12  allows unrestricted flow of high pressure fluid through swivel  12  to minimize pressure drop. Swivel  12  also includes a bearing that provides sufficient axial strength to counter the load generated by high pressure fluid within swivel  12 , and radial strength to bear the weight of spool  16  and the hose. 
         [0011]      FIG. 2  is a cross-sectional view of hose reel  10  of  FIG. 1  showing high pressure swivel  12  having inlet housing  32  and outlet housing  34  connected by swivel shaft  36 . Swivel  12  also includes retainer  38  and hub  40 . Spool  16  and outlet housing  34  are configured to rotate about axis A, while inlet housing  32  and frame  14  remain stationary. 
         [0012]    Inlet housing  32  and retainer  38  are connected to each other via fasteners (not shown) such that sidewall  20 A is clamped in between. Thus, inlet housing  32 , retainer  38  and all of frame  14  remain stationary during operation of hose reel  10 . Inlet housing  32  may be positioned in different circumferential orientations about axis A with respect to frame  14  to accommodate different supply hose positions. 
         [0013]    Swivel shaft  36  is positioned along axis A and is configured to rotate with spool  16 . Swivel shaft  36  extends through an opening in disk  24 A and an opening in hub  40 . Disk  24 A is clamped in between swivel shaft  36  and hub  40 . As such, hub  40  and swivel shaft  36  rotatable about axis A with spool  16 . Swivel shaft  36  is inserted through retainer  38  and into inlet housing  32 . Outlet housing  34  is also connected to swivel shaft  36  within drum  22 . Outlet housing  34  extends through an opening in drum  22 . 
         [0014]    Inlet housing  32 , swivel shaft  36  and outlet housing  34  include interior flow passages through which fluid may flow, as is discussed with reference to  FIG. 3 . Thus, a supply hose can be connected to inlet housing  32  to provide high pressure fluid to outlet housing  34 , which can be connected to a distribution hose wound around drum  22  between disks  24 A and  24 B. Union fittings may be used to join hoses to inlet housing  32  and outlet housing  34 . Alternatively, a hose may be directly coupled to swivel shaft  36  without the use of outlet housing  34 . 
         [0015]    As will be discussed in greater detail with reference to  FIGS. 3 and 4 , retainer  38  includes ball bearings situated between a stationary race and a rotating race that permit swivel shaft  36  to rotate within retainer  38  and inlet housing  32 . Swivel shaft  36  includes a non-restricted fluid passage through swivel  12  that allows for coupling to inlet housing  32  and outlet housing  34  without producing a pressure drop. In order to accommodate swivel shaft  36  within swivel  12  and to allow the fluid passage within swivel shaft  36  to pass through retainer  38 , hub  40 , disk  24 A without producing a restriction, retainer  38  includes ball bearing races that counteract the axial and radial forces generated by operation of hose reel  10  and the high pressure fluid flowing between inlet housing  32  and outlet housing  34 . 
         [0016]      FIG. 3  is a close-up cross-sectional view of hose reel swivel  12  of  FIG. 2  showing inner and outer bearing races  42 A and  42 B surrounding swivel shaft  36 . Swivel shaft  36  includes shaft  44 , outlet socket  46 , flange  48  and fluid passage  50 . Inlet housing  32  includes flange  52 , socket  54  and fluid passage  56 . Outlet housing  34  includes flange  58  and fluid passage  60 . Ball bearings  62  are positioned between the stationary outer race  42 A and the rotating inner race  42 B. Although outer race  42 A is shown integrally formed from retainer  38 , outer race  42 A may be provided by a separate piece positioned within a pocket inside retainer  38 . 
         [0017]    As discussed above, inlet housing  32  is joined to retainer  38  to mount hose reel swivel  12  to sidewall  20 A. In particular, flange  52  is connected to outer race  42 A via fasteners (not shown). Thus, outer race  42 A and inlet housing  32  are held stationary via mounting to frame  14  via sidewall  20 A. Hub  40  is joined to swivel shaft  36  to mount outlet housing  34  to disk  24 A. In particular, hub  40  is connected to outlet socket  46  of swivel shaft  36  via fasteners (not shown) at locations  64 . Shaft  44  of swivel shaft  36  extends from outlet socket  46  to pass through bore  68 A in disk  24 A, bore  68 B in hub  40  and bore  68 C in retainer  38 , and into socket  54 . Thus, shaft  44  and inner race  42 B rotate along with disk  24 A of spool  16 . Ball bearings  62  roll between outer race  42 A and inner race  42 B. 
         [0018]    Outlet housing  34  is inserted into outlet socket  46  within swivel shaft  36  until flange  58  engages outlet socket  46 . Inner race  42 B is mounted on shaft  44  within channel  70  of outer race  42 A, and is retained by threaded connection and secured by split ring  75 . Inner race  42 B is thus rotatable with swivel shaft  36 , while outer race  42 A is held in place via sidewall  20 A. Connected as such, fluid passages  56 ,  50  and  60  are fluidly connected. Fluid passage  50  extends from flange  52 , through retainer  38  and hub  40  and into outlet socket  46  in a linear fashion, thereby eliminating any constrictions between fluid passages  56  and  60 . 
         [0019]    Swivel  12  is provided with a variety of different seals, including fluid seals  76 A and  76 B and bearing seals  78 A and  78 B. In the depicted embodiment, fluid seal  76 A comprises an inner plastic sealing member and an outer elastomeric o-ring. However, fluid seal  76 A may comprise other off-the-shelf seals, such as o-rings, lip seals and the like. In the depicted embodiment, fluid seal  76 B and bearing seals  78 A and  78 B comprise o-ring seals, but may be other types of seals. Bearing seals  78 A and  78 B protect ball bearings  62  and races  42 A and  42 B from environmental elements, and may also be used to retain lubricant, such as grease, within races  42 A and  42 B. Fluid seals  76 A and  76 B prevent fluid traveling through fluid passages  50 ,  56  and  60  from leaking out of swivel  12 . 
         [0020]    Due to the load generated by pressure and large cross-sectional flow areas through fluid passages  50 ,  56  and  60 , the axial loading within swivel  12  is greater than conventional hose reel swivels. Inner race  42 A and outer race  42 B are shaped to provide contact surfaces along ball bearings  62  that provide radial and axial support to swivel  12 . 
         [0021]      FIG. 4  is a close-up cross-sectional view of ball bearing  62  positioned between rotating, inner race  42 B and stationary, outer race  42 A of  FIG. 3 . Outer race  42 A includes axial land  80 A and radial land  82 A, while inner race  42 B includes axial land  80 B and radial land  82 B. Frusto-conical portion  84 A intervenes between axial land  80 A and radial land  82 A, while frusto-conical portion  84 B intervenes between axial land  80 B and radial land  82 B. 
         [0022]    Axial lands  80 A and  80 B each form arcuate lands that have generally radial extending surfaces that circumscribe axis A. Axial land  80 A and axial land  80 B have approximately the same radius such that they oppose each other. Axial load L A  is borne by axial lands  80 A and  80 B, which is ultimately transmitted to fasteners (not shown) that couple flange  52  of inlet housing  32  with retainer  38  (see  FIG. 3 ). Axial lands  80 A and  80 B have radii of curvature C that is slightly larger than the radius of ball bearing  62 , thereby resulting in linear contact between ball bearing  62  and lands  80 A and  80 B. 
         [0023]    Radial lands  82 A and  82 B each form cylindrical lands that circumscribe axis A. Radial land  82 A has a larger radius than radial land  82 B, and radial land  82 A radially overlaps radial land  82 B. Radial load L R  is borne by radial lands  82 A and  82 B, which is ultimately transmitted to retainer  38  via ball bearings  62 . Ball bearings  62  also permit shaft  44  of swivel shaft  36  to rotate within retainer  38  and socket  54  of inlet housing  32 . Radial lands  82 A and  82 B are generally planar, thereby resulting in point contact between ball bearing  62  and lands  82 A and  82 B. Step  86  on shaft  44  engages with inner race  42 B to prevent translation of swivel shaft  36  under force from axial load L A . 
         [0024]    Axial load L A  and radial load L R  are not transmitted at the edges of races  42 A and  42 B, as would occur in a conventional ball bearing arrangement. Axial lands  80 A and  80 B are positioned in central portions of races  42 A and  42 B, respectively, away from the edges of the races. Radial lands  82 A and  82 B are positioned at the edges of races  42 A and  42 B, respectively, but extend beyond the point of contact with radial load L R  to space the load away from the edge of the race. Radial land  82 A forms an extended or extruded portion of race  42 A that is tangent to radial load L R . Likewise, radial land  82 B forms an extended or extruded portion of race  42 B that is tangent to radial load L R . 
         [0025]    Lands  80 A and  82 A are separated by frusto-conical portion  84 A, which circumscribe a segment of ball bearing  62  of about fifty degrees or less. Likewise, lands  80 B and  82 B are separated by frusto-conical portion  84 B, which circumscribes a segment of ball bearing  62  of about fifty degrees or less. Portions  84 A and  84 B are curved such that ball bearing  62  will not ever engage portions  84 A and  84 B. Frusto-conical portions  84 A and  84 B, however, provide a gradual blending between axial lands  80 A and  80 B and radial lands  82 A and  82 B, respectively, to reduce stress concentrations in races  42 A and  42 B. 
         [0026]    One advantage of swivel  12  is that there are no restrictions in fluid passages  50 ,  56  and  60 , which is at least partially enabled by the load bearing capabilities of races  42 A and  42 B. The result of this is lower pressure drop through swivel  12 , which enables higher flow rates. Other advantages include higher pressure ratings and the ability to carry the pressure load, higher hose reel swivel life due to optimized bearing load transmission, and lower turning torques required for spool  16 , which lowers the spring and or motor power required to operate the reel. Swivel  12  provides bearing support for high axial loads induced by high pressures in fluid passage  50  and also radial loads from the weight of spool  16  and hose. The shape of races  42 A and  42 B minimizes Hertzian contact stress concentrations at the bearing race edges. The entire package of swivel  12  allows for a narrower reel footprint which is a desired customer feature. 
         [0027]    Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.