Hydraulic assist wheel end

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'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.

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.

DETAILED DESCRIPTION OF THE INVENTION

Illustrated inFIG. 1is a hydraulic assist wheel end10that comprises a motor11, a wheel drum12, and a steerable knuckle13. A hub36is rotatably mounted radially outboard to the knuckle13. The hub36is drivingly connected to the motor11so that when the motor11is energized, it causes the hub36to rotate. The motor11may be such as those produced by Poclain Hydraulics Industrie of France.

The hub36has a bolt flange38with a plurality of bolt apertures40. The wheel drum12is located radially outward from the hub36. The drum12has a bolt flange42that abuts the bolt flange38of the hub36. The drum bolt flange42has a plurality of apertures44that align with the apertures in the hub bolt flange apertures46. Bolts14are located through the hub bolt flange apertures46and the drum bolt flange apertures44to fixedly connect the hub36and the wheel drum12.

The hub36and the drum12rotate about the centerline C of the knuckle13by way of bearings17A,17B which are located between the knuckle13and the hub36.

The knuckle13has an inboard portion18that defines an upper arm19and a lower arm20. A kingpin15, which is located between the upper arm19and the lower arm20pivotably connects an end portion of an axle16of a vehicle (not shown) to the knuckle inboard portion18, permits the vehicle to be steered about a centerline D of the kingpin15. The knuckle13also has an outboard portion21that defines a spindle22. The outboard portion21is adapted to cooperate with the fluid driven motor11. Preferably, the motor11has a circular recess48for receiving the outboard portion21of the cylindrical spindle22.

The arms19,20define a cavity23where the end portion of the axle16is pivotally received. A knuckle connecting wall24connects a knuckle upper wall25and a knuckle lower wall26together.

A first fluid pressure supply port27and a second fluid pressure supply port28are located on an upper surface29of the upper arm19of the knuckle inboard portion18radially outward from the upper wall25of the knuckle13for communicating fluid to the motor11. Fluid flowing through the first pressure supply port27, via pressure supply line A (hidden), rotates the motor11in a first direction, thus causing the wheel drum12to move, for example, in a forward direction.

Alternatively, fluid may be communicated to the motor11through pressure supply line B via second pressure supply port28. In this case, the motor11would 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 lines30,31are oriented substantially parallel one another near the centerline C of the knuckle13for draining fluid from the motor11. The lines30,31extend from the outboard portion21to ports32,33located in the connecting wall24of the knuckle13. Line30is shown draining hydraulic fluid from the motor11and a portion of the knuckle13, while line31is shown draining hydraulic fluid from another portion of the knuckle13. Although not shown in the particular cut away ofFIG. 1, line31is also in direct fluid communication with the motor11itself. The lines30,31may be connected to a sump system (not shown).

A first internal drain port34is preferably located between the inner bearing17A and the outer bearing17B. The internal drain port34is substantially oriented perpendicularly to the return drain line31. The internal drain port34can be utilized to drain fluid to the return drain line31.

A second internal drain port35is located outboard of the outer bearing17B. The internal drain port35is substantially oriented perpendicularly to the return drain line30. The internal drain port35can be utilized to drain fluid to the return drain line30.

As a result of locating the fluid pressure supply ports27,28on the upper surface29of the upper arm19, close to the periphery of the kingpin15about the kingpin steer axis centerline D, the supply ports27,28would be connected to supply hoses that are shown as hidden lines inFIG. 1. Here, the supply hoses are formed in a small travel arc that follows closely the circular curvature of the kingpin15.

Also, as a result of disposing the drain lines30,31parallel to the centerline C of the knuckle13, the drain ports32,33would be connected to drain hoses that are shown as hidden lines inFIG. 1. Here, the drain hoses are formed in a small travel arc that follows closely the circular curvature of the kingpin15.

Thus, the supply and drain hoses would effectively allow the hydraulic assist wheel end10to 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 surface29of the upper arm19of the knuckle13, 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 ports27,28are at least prevented from being damaged in the same ways.

FIG. 2illustrates an alternate embodiment vehicle hydraulic assist wheel end10′ with the motor11, the wheel drum12, the knuckle13, the hub36, and the inner bearing17A and the outer bearing17B.

The fluid pressure supply port27or28is also shown connected to its corresponding supply line A/B and located on the upper surface29.

Also shown is a first spacer52disposed between and abutting an outer race60of the inner bearing17A and also an outer race62of the outer bearing17B. The spacer52has an inner landing54and an outer landing56with an angled landing portion58therebetween.

An outboard portion70of the outer landing56is also in contact with an inwardly extending portion72of the hub36. The outer race62of the outer bearing17B is seated within the inwardly extending portion72of the hub36.

An inboard portion of74of the inner landing54is also in contact with an inwardly extending portion76of the hub36. The outer race60of the inner bearing17A is seated within the inwardly extending portion74of the hub36.

The inner landing54has a greater outer diameter than an outer diameter of the outer landing56. Thus, the function of the angled landing portion58is to connect the landings54,56.

The spacer also comprises an inwardly disposed surface68that extends radially inward from the land56. The inside diameter surface68extends radially inwardly in close proximity clearance to the spindle22outside diameter.

Spacers52of various sizes may be used, which at least permits the use of the same spindle12and motor11while adapting to wheel assemblies of varying sizes. The vehicle hydraulic assist wheel end10ofFIG. 1has no spacer disposed between and abutting the races60,62. Preferably, the spacer52is unitary and one piece.

FIG. 3illustrates a second alternate embodiment vehicle hydraulic assist wheel end10″ with the motor11, the wheel drum12, the knuckle13, the hub36, and the inner bearing17A and the outer bearing17B.

The fluid pressure supply port27or28is also shown connected to its corresponding supply line A/B and still located on the upper surface29.

A second spacer64is located radially outward from the outboard portion21of the knuckle13. The spacer64preferably has a flat outboard surface78in direct contact with an inner race80of the outboard bearing17B. A flat inboard surface82is in direct contact with an inner race84of the inboard bearing17A. A flat radially outermost surface86is in close proximity clearance66with an inwardly extending hub portion88. In all embodiments, the bearings17A,17B rotatingly support the hub36about the knuckle13. The second spacer64may be of a one piece, unitary construction.

Spacers64of various sizes may be used, which at least permits the use of the same spindle12and motor11while adapting to wheel assemblies of varying sizes. Preferably, the spacer64is 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.