Abstract:
A steerable vehicle knuckle has an inboard portion defining upper and lower arms, with a kingpin between them, and has an outboard portion defining a spindle that cooperates with a fluid driven motor. The arms define a cavity where an axle end portion is pivotally received. Fluid supply ports, which supply fluid to energize the motor, are located on an upper surface of the knuckle&#39;s inboard portion. Fluid drain lines extend within the knuckle from the motor to the cavity and are utilized to drain fluid from the motor. The supply ports and drain lines are each connected to separate hoses formed in a small arc that follows closely the circular curvature of the kingpin. This arrangement of port, lines, and hoses is less expensive to produce, easier to package, more robust, allows for faster steering reaction, and is easier to assemble than conventional arrangements.

Description:
RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/036,670 filed Mar. 14, 2008, the entirety of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a vehicle knuckle that is adapted to cooperate with a fluid driven motor. More particularly, the present invention relates to a steerable vehicle knuckle with an inventive fluid supply, return and drain lines and other fluid paths for communicating fluid to and from a fluid driven motor. 
     BACKGROUND OF THE INVENTION 
     Those skilled in the art know that some vehicles, such as trucks, farm vehicles, and heavy duty construction vehicles, have wheels that are driven by hydraulic drive motors located at the wheels. Typically, each wheel end has a knuckle that utilizes a plurality of large hydraulic fittings that function as supply, return and drain ports. The ports are typically located all about the knuckle. Hoses, which are connected to these fittings at these locations, are required to traverse a large arc when the axle is steered. Such an arrangement of fittings and hoses, however, is difficult to package within the vehicle and uses large amounts of hose material. 
     A few examples of methods of providing fluid to a hydraulically driven wheel include devices described in the following patents. U.S. Pat. No. 4,171,732 discloses a fluid supply port on an upper surface of an inboard portion of a knuckle. The fluid return port, however, is located on a lower surface of the inboard portion. This design causes significant problems in packaging the hoses attached to these ports. Additionally, the fluid return hose, being located below the spindle, is highly susceptible to damage from items on the ground and from the ground itself. 
     U.S. Pat. No. 3,612,204 teaches a rigid fluid supply and return lines fixedly attached to an upper portion of a boss. The motor may pivot about the boss to provide steering to a wheel. As can be appreciated by FIG. 7 of this patent, the fixed fluid lines take up a tremendous amount of space at the wheel end. 
     U.S. Pat. No. 4,111,618 discloses supply and return lines all entering the spindle substantially parallel with the spindle centerline. The supply lines are located above/below the drain line, the drain line is at the centerline. All fluid lines are arranged about the centerline of the spindle and enter the spindle at this point as well. 
     As can be appreciated from the above discussion, some designs require a large amount of hose material and require that the fluid hoses traverse a large arc when the axle steers, which is difficult to package. Thus, a vehicle having hydraulic hoses connected to a wheel end having a hydraulic motor disposed thereon, may benefit from an arrangement of hydraulic hoses that does not require a large amount of hose material and does not require a wide arc for the hoses to traverse when the wheel end is steered in various directions. Such an arrangement would be less expensive to produce, easier to package, more robust, allow for faster steering reaction, and would be more easily connectable at the time of assembly of the vehicle. 
     SUMMARY OF THE INVENTION 
     A vehicle knuckle is disclosed that has an inboard portion that defines an upper arm and a lower arm. The knuckle also has an outboard portion that defines a spindle. The outboard portion is adapted to cooperate with a fluid driven motor. The arms define a cavity where an end portion of an axle is pivotally received. A connecting wall of the cavity connects an upper wall and a lower wall, also of the cavity, together. Fluid supply ports are located on an upper surface of the upper arm of the inboard portion adjacent the upper wall of the cavity for communicating fluid to the motor. Fluid drain lines are oriented substantially parallel one another near a centerline of the knuckle for draining fluid from the motor. The drain lines extend from the outboard portion to ports located in the connecting wall of the cavity. 
     Further advantages of the present invention will be apparent from the following description and appended claims, reference being made to the accompanying drawings forming a part of a specification, wherein like reference characters designate corresponding parts of several views. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a three dimensional cut away view of a vehicle hydraulic assist wheel end in accordance with the present invention; 
         FIG. 2  is a partial cross-sectional view of an alternate embodiment of a vehicle hydraulic assist wheel end in accordance with the present invention; and 
         FIG. 3  is a partial cross-sectional view of a second alternate embodiment of a vehicle hydraulic assist wheel end in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It is to be understood that the present invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions, directions, or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless the claims expressly state otherwise. 
     Illustrated in  FIG. 1  is a hydraulic assist wheel end  10  that comprises a motor  11 , a wheel drum  12 , and a steerable knuckle  13 . A hub  36  is rotatably mounted radially outboard to the knuckle  13 . The hub  36  is drivingly connected to the motor  11  so that when the motor  11  is energized, it causes the hub  36  to rotate. The motor  11  may be such as those produced by Poclain Hydraulics Industrie of France. 
     The hub  36  has a bolt flange  38  with a plurality of bolt apertures  40 . The wheel drum  12  is located radially outward from the hub  36 . The drum  12  has a bolt flange  42  that abuts the bolt flange  38  of the hub  36 . The drum bolt flange  42  has a plurality of apertures  44  that align with the apertures in the hub bolt flange apertures  46 . Bolts  14  are located through the hub bolt flange apertures  46  and the drum bolt flange apertures  44  to fixedly connect the hub  36  and the wheel drum  12 . 
     The hub  36  and the drum  12  rotate about the centerline C of the knuckle  13  by way of bearings  17 A,  17 B which are located between the knuckle  13  and the hub  36 . 
     The knuckle  13  has an inboard portion  18  that defines an upper arm  19  and a lower arm  20 . A kingpin  15 , which is located between the upper arm  19  and the lower arm  20  pivotably connects an end portion of an axle  16  of a vehicle (not shown) to the knuckle inboard portion  18 , permits the vehicle to be steered about a centerline D of the kingpin  15 . The knuckle  13  also has an outboard portion  21  that defines a spindle  22 . The outboard portion  21  is adapted to cooperate with the fluid driven motor  11 . Preferably, the motor  11  has a circular recess  48  for receiving the outboard portion  21  of the cylindrical spindle  22 . 
     The arms  19 ,  20  define a cavity  23  where the end portion of the axle  16  is pivotally received. A knuckle connecting wall  24  connects a knuckle upper wall  25  and a knuckle lower wall  26  together. 
     A first fluid pressure supply port  27  and a second fluid pressure supply port  28  are located on an upper surface  29  of the upper arm  19  of the knuckle inboard portion  18  radially outward from the upper wall  25  of the knuckle  13  for communicating fluid to the motor  11 . Fluid flowing through the first pressure supply port  27 , via pressure supply line A (hidden), rotates the motor  11  in a first direction, thus causing the wheel drum  12  to move, for example, in a forward direction. 
     Alternatively, fluid may be communicated to the motor  11  through pressure supply line B via second pressure supply port  28 . In this case, the motor  11  would rotate in a second direction, opposite the first direction, thus causing the wheel assembly to move, for example, in a rearward direction. 
     Two fluid return drain lines  30 ,  31  are oriented substantially parallel one another near the centerline C of the knuckle  13  for draining fluid from the motor  11 . The lines  30 ,  31  extend from the outboard portion  21  to ports  32 ,  33  located in the connecting wall  24  of the knuckle  13 . Line  30  is shown draining hydraulic fluid from the motor  11  and a portion of the knuckle  13 , while line  31  is shown draining hydraulic fluid from another portion of the knuckle  13 . Although not shown in the particular cut away of  FIG. 1 , line  31  is also in direct fluid communication with the motor  11  itself. The lines  30 ,  31  may be connected to a sump system (not shown). 
     A first internal drain port  34  is preferably located between the inner bearing  17 A and the outer bearing  17 B. The internal drain port  34  is substantially oriented perpendicularly to the return drain line  31 . The internal drain port  34  can be utilized to drain fluid to the return drain line  31 . 
     A second internal drain port  35  is located outboard of the outer bearing  17 B. The internal drain port  35  is substantially oriented perpendicularly to the return drain line  30 . The internal drain port  35  can be utilized to drain fluid to the return drain line  30 . 
     As a result of locating the fluid pressure supply ports  27 ,  28  on the upper surface  29  of the upper arm  19 , close to the periphery of the kingpin  15  about the kingpin steer axis centerline D, the supply ports  27 ,  28  would be connected to supply hoses that are shown as hidden lines in  FIG. 1 . Here, the supply hoses are formed in a small travel arc that follows closely the circular curvature of the kingpin  15 . 
     Also, as a result of disposing the drain lines  30 ,  31  parallel to the centerline C of the knuckle  13 , the drain ports  32 ,  33  would be connected to drain hoses that are shown as hidden lines in  FIG. 1 . Here, the drain hoses are formed in a small travel arc that follows closely the circular curvature of the kingpin  15 . 
     Thus, the supply and drain hoses would effectively allow the hydraulic assist wheel end  10  to pivot about the kingpin steer axis centerline D when the vehicle is being steered. 
     By reducing the travel arc for these hoses, the space (area) taken up by the hoses is greatly reduced. It can be appreciated that since the hoses do not travel through a large arc when the spindle is turned, that less hose material can be used. Thus, less drain hose material is required to accomplish the same function as the prior art designs. Additionally, by locating both of the supply hoses together on an upper surface  29  of the upper arm  19  of the knuckle  13 , the hoses are prevented from coming in contact with the ground or obstacles on, propelled from, or protruding from the ground that may damage the hoses. Also, the pressure supply ports  27 ,  28  are at least prevented from being damaged in the same ways. 
       FIG. 2  illustrates an alternate embodiment vehicle hydraulic assist wheel end  10 ′ with the motor  11 , the wheel drum  12 , the knuckle  13 , the hub  36 , and the inner bearing  17 A and the outer bearing  17 B. 
     The fluid pressure supply port  27  or  28  is also shown connected to its corresponding supply line A/B and located on the upper surface  29 . 
     Also shown is a first spacer  52  disposed between and abutting an outer race  60  of the inner bearing  17 A and also an outer race  62  of the outer bearing  17 B. The spacer  52  has an inner landing  54  and an outer landing  56  with an angled landing portion  58  therebetween. 
     An outboard portion  70  of the outer landing  56  is also in contact with an inwardly extending portion  72  of the hub  36 . The outer race  62  of the outer bearing  17 B is seated within the inwardly extending portion  72  of the hub  36 . 
     An inboard portion of  74  of the inner landing  54  is also in contact with an inwardly extending portion  76  of the hub  36 . The outer race  60  of the inner bearing  17 A is seated within the inwardly extending portion  74  of the hub  36 . 
     The inner landing  54  has a greater outer diameter than an outer diameter of the outer landing  56 . Thus, the function of the angled landing portion  58  is to connect the landings  54 ,  56 . 
     The spacer also comprises an inwardly disposed surface  68  that extends radially inward from the land  56 . The inside diameter surface  68  extends radially inwardly in close proximity clearance to the spindle  22  outside diameter. 
     Spacers  52  of various sizes may be used, which at least permits the use of the same spindle  12  and motor  11  while adapting to wheel assemblies of varying sizes. The vehicle hydraulic assist wheel end  10  of  FIG. 1  has no spacer disposed between and abutting the races  60 ,  62 . Preferably, the spacer  52  is unitary and one piece. 
       FIG. 3  illustrates a second alternate embodiment vehicle hydraulic assist wheel end  10 ″ with the motor  11 , the wheel drum  12 , the knuckle  13 , the hub  36 , and the inner bearing  17 A and the outer bearing  17 B. 
     The fluid pressure supply port  27  or  28  is also shown connected to its corresponding supply line A/B and still located on the upper surface  29 . 
     A second spacer  64  is located radially outward from the outboard portion  21  of the knuckle  13 . The spacer  64  preferably has a flat outboard surface  78  in direct contact with an inner race  80  of the outboard bearing  17 B. A flat inboard surface  82  is in direct contact with an inner race  84  of the inboard bearing  17 A. A flat radially outermost surface  86  is in close proximity clearance  66  with an inwardly extending hub portion  88 . In all embodiments, the bearings  17 A,  17 B rotatingly support the hub  36  about the knuckle  13 . The second spacer  64  may be of a one piece, unitary construction. 
     Spacers  64  of various sizes may be used, which at least permits the use of the same spindle  12  and motor  11  while adapting to wheel assemblies of varying sizes. Preferably, the spacer  64  is of a unitary, one piece construction. 
     It is to be understood that the patent drawings are not intended to define precise proportions of the elements of the invention but that the patent drawings are intended to be utilized in conjunction with the rest of the specification. Unless expressly specified to the contrary, it should also be understood that the illustrated differences between various elements of the invention, which may be in fractions of a unit of measurement, are not intended to be utilized to precisely measure those differences between the various elements. 
     In accordance with the provisions of the patent statutes, the principles and modes of operation of this invention have been described and illustrated in its preferred embodiments. However, it must be understood that the invention may be practiced otherwise than specifically explained and illustrated without departing from its spirit or scope.