Patent Publication Number: US-9835211-B2

Title: Brake assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 13/231,168 filed on Sep. 13, 2011, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This invention relates to a brake assembly adapted to mount to an axle housing on a vehicle. More particularly, this invention relates to such a brake including mounting sleeves to facilitate mounting the brake to the mounting flange on the axle housing of a vehicle. 
     BACKGROUND ART 
     A variety of braking systems are known and commercially available, and are used on all types of vehicles. For example, caliper brakes utilize opposed brake pads to apply a stopping force to the planar surfaces of a rotating disc. Similarly, drum brakes rely upon brake shoes to apply a stopping force to the interior of a rotating drum. Multi-disc brakes utilize a plurality of alternating stationary and rotating discs that, when compressed together, apply a braking force on a rotating hub or axle. In each case, the brakes must be mounted to the vehicle adjacent to one or several rotating wheels. Small openings near the wheels and the presence of other vehicle components can make mounting the brake in the desired position difficult, and can sometimes restrict the size or type of the brake that may be used on a specific vehicle. Available locations for mounting the brake must also be taken into consideration. 
     In some vehicles the brakes are adapted to be mounted to the axle housing via a mounting flange extending from a distal end of the housing. A rotating hub is typically located outside the axle housing, and the brake must be adapted to apply a stopping force to the rotating hub or a drum that is rotationally secured to the hub. One such axle is the Model 18 axle manufactured by Dana Holding Corporation of Maumee, Ohio. Such a conventional brake and axle assembly is shown in  FIG. 1 , and includes an axle A and a rotating hub H positioned on the end of axle A. A drum D is rotationally secured to hub H, and therefore rotates with axle A. A brake B is secured around hub H and includes brake shoes S that, when actuated, apply a braking force to the interior of rotating drum D. An axle housing X is positioned around axle A and includes a flange F at an end thereof adjacent hub H. A plurality of holes extend through flange F and are adapted to receive a plurality of bolts to secure brake B to axle housing X. Brake B includes a stationary plate P having holes that align with the holes through flange F and that acts to secure the brake to the axle housing. 
     Due to the size of flange F, the mounting bolts extending therethrough must include a head having a flat portion Z on an outer radial surface so that the bolt may be fully inserted through the hole in the flange without engaging the axle housing X. Because the bolt cannot rotate within the hole, a nut must be positioned on the interior of brake B to secure the brake to the axle housing. The use of unique bolts to secure brake B to axle housing X increases costs, and also may make finding replacements difficult in some instances. In addition, the inclusion of a nut on the interior of brake B makes mounting or removal of brake B more difficult, and effectively limits the types of brakes that may be used. A wet brake, including lubricating and cooling oil in the interior of the brake, would present significant problems if such a mounting assembly were included. Access to the interior of the brake to allow for mounting or removal of the brake would require that all brake fluid first be drained from the brake. 
     Conventional brake assemblies, as shown in  FIG. 1 , also suffer from the disadvantage of not having an effective seal to prevent water and dirt intrusion into the internal braking area. Such a braking assembly includes only one gasket G that is compressed between the stationary plate P and a rotating journal J of the hub H. The gasket G fails to prevent water intrusion into the spline of the wheel hub H. The water that enters the spline of the wheel hub may then travel to the axle bearings in the axle housing. Water intrusion decreases both bearing and brake life. 
     Thus, there is a need for an improved brake assembly that solves one or more of the deficiencies of the prior art. 
     DISCLOSURE OF THE INVENTION 
     It is thus an object of one aspect of the present invention to provide a brake having an improved mounting assembly. 
     It is an object of another aspect of the present invention to provide a brake, as above, having mounting sleeves secured to one side of an axle flange. 
     It is an object of an additional aspect of the present invention to provide a brake, as above, which includes threaded holes extending into a portion of the brake housing. 
     It is an object of yet another aspect of the present invention to provide a brake, as above, which is provided with an improved sealing assembly to prevent water infiltration into the interior of the braking cavity. 
     These and other objects of the present invention, as well as the advantages thereof over existing prior art forms, which will become apparent from the description to follow, are accomplished by the improvements hereinafter described and claimed. 
     In general, a brake assembly according to the concepts of the present invention is adapted to be mounted to a flange of an axle housing, the flange including a plurality of holes therethrough. The brake includes a stationary plate having a plurality of threaded holes. The brake also includes a mounting sleeve positioned adjacent to the axle housing flange on a side opposite the stationary plate, and a plurality of holes through the mounting sleeve. A plurality of bolts having a threaded portion and a head are received in the holes in the mounting sleeve, the holes through the axle housing flange, and the threaded holes in the stationary plate to secure the brake to the axle housing. 
     In accordance with another aspect of the present invention, a wheel hub assembly includes an axle, an axle housing having a flange, and a brake assembly secured to the axle housing flange. The brake assembly includes a stationary plate having a plurality of threaded holes. A mounting sleeve is positioned adjacent to the axle housing flange on a side opposite the stationary plate, and a plurality of holes are provided through the mounting sleeve. A plurality of bolts having a threaded portion and a head are received in the holes in the mounting sleeve, the holes through the axle housing flange, and the threaded channels to secure the brake to the axle housing. 
     In accordance with another aspect of the present invention, a brake assembly is adapted to be mounted to a flange of an axle housing. The brake assembly includes a brake housing having a stationary plate and a plurality of threaded holes extending partially through the stationary plate. A generally annular mounting sleeve is adapted to be positioned around the axle housing on a side of the flange opposite the stationary plate, the mounting sleeve including more than one piece. A plurality of holes are provided through the mounting sleeve and are aligned with the threaded holes in the stationary plate. A plurality of bolts having a threaded end are received in the holes in the mounting sleeve and the threaded holes in the stationary plate to secure the brake housing to the axle housing. 
     A preferred exemplary brake according to the concepts of the present invention is shown by way of example in the accompanying drawings without attempting to show all the various forms and modifications in which the invention might be embodied, the invention being measured by the appended claims and not by the details of the specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of a prior art brake and mounting assembly. 
         FIG. 2  is a sectional view of the brake assembly and a portion of an axle according to the concepts of the present invention. 
         FIG. 3  is an enlarged sectional view of a portion of the brake assembly as indicated in  FIG. 2 . 
         FIG. 4  is a front elevational view of the brake assembly of  FIG. 2  showing the stationary plate and the mounting sleeves. 
         FIG. 5  is a rear elevational view of the brake assembly of  FIG. 2  showing the rotating hub and the end cap. 
         FIG. 6  is an enlarged sectional view of a portion of the brake assembly as indicated in  FIG. 2 . 
         FIG. 7  is a sectional view of the parking brake actuating mechanism taken substantially along line  6 - 6  of  FIG. 4 . 
     
    
    
     PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION 
     A brake made in accordance with the present invention is indicated generally by the numeral  10 . Brake  10  is mounted to an axle housing  12  that surrounds and substantially encloses an axle  14 . A hub  16  and a brake  10  are rotationally secured on each end of the vehicle axle  14 , although only a single hub and brake is shown in the drawings. It will be appreciated by those skilled in the art that the axle, hub and brake assemblies at opposing ends of the vehicle axle  14  are identical except for the orientation of the components. Axle  14  includes a splined section  15  on an exterior surface, and hub  16  includes a splined section  17  on an interior surface, the splines  15  of the axle and the splines  17  of the hub engaging one another to rotationally couple the two components together. An end of hub  16  includes a plurality of lug bolts  18  adapted to receive a vehicle wheel thereon, as is well known in the art. 
     Brake  10  includes a stationary plate  20  that is secured to axle housing  12  and is positioned around hub  16 . Stationary plate  20  is generally circular in shape and includes a central bore therethrough. A bearing  22  is provided between stationary plate  20  and hub  16  to allow the hub to rotate independent of the stationary plate. Stationary plate  20  may include a variety of recesses and/or projections extending in an axial direction to accommodate other brake components. A lip  24  extends generally orthogonally from the outer radial edge of stationary plate  20  in a direction opposite axle housing  12 . 
     A bowl-shaped cover plate  26  is positioned around hub  16  and engages stationary plate  20  to define a portion of a fluid-tight inner chamber  28 . The stationary plate  20  and the cover plate  26  together form a brake housing that encloses other brake components. Cover plate  26  includes an inner axially extending neck  30  adjacent hub  16 , a generally planar radial body  32  and an axially extending arm  34  positioned at on outer radial edge of body  32 . Cover plate  26  is sized so that arm  34  is positioned interiorly of lip  24  of stationary plate  20 . A sealing member  36  is provided between arm  34  and lip  24  to create a fluid-tight seal therebetween. A bearing  38  is provided between hub  16  and neck  30  of cover plate  26  to allow rotation of the hub independent of the cover plate. In addition to sealing member  36 , sealing members  40  and  42  are provided between cover plate  26  and hub  16 , and between stationary plate  20  and hub  16 , respectively. Sealing members  36 ,  40  and  42 , along with stationary plate  20 , cover plate  26  and hub  16 , define the fluid-tight inner chamber  28 . 
     A conventional disc stack  48  is provided within inner chamber  28 . As such, disc stack  48  includes a plurality of alternating stationary discs  51   a  and rotating discs  51   b  ( FIG. 2 ). The rotating discs include internal splines and are rotationally secured around hub  16 , which includes external splines. The stationary discs are also positioned around hub  16  but are not rotationally engaged therewith. Instead, the stationary discs are prevented from rotational movement by an anchor. For example, each stationary disc may include an ear  49 , and a bolt or other projection  50  may be received through each ear  49  and may be secured to stationary plate  20  and/or cover plate  26  to prevent rotation of the stationary discs  51   a . Both the rotating discs  51   b  and stationary discs  51   a  are free to move axially along hub  16 . The rotating discs  51   b  include a high friction surface thereon so that a braking force is created when the disc stack  48  is compressed and the stationary discs  51   a  contact the high friction surface of the rotating discs  51   b , as is known to those skilled in the art. 
     Any actuating mechanism known to those skilled in the art may be employed to actuate brake  10  and compress disc stack  48 . The embodiment depicted in the drawings includes a ball ramp actuating mechanism. The ball ramp actuator includes a rotatable actuator  52  that is positioned within inner chamber  28  adjacent to disc stack  48 . As is known in the art, rotatable actuator  52  and stationary plate  20  each include a plurality of depressions of decreasing depth, and balls positioned between opposing depressions. A hydraulic cylinder assembly  53  engages rotatable actuator  52  causing it to rotate about an axis Y, thereby causing the balls positioned within the depressions to move along the depressions toward the shallower ends. This rotation causes rotatable actuator  52  to move axially away from stationary plate  20 , thereby inducing compression of disc stack  48 . A needle bearing  54  may be positioned between rotatable actuator  52  and disc stack  48  to prevent the transfer of rotational movement between the disc stack  48  and the rotatable actuator  52 . Such a ball ramp actuating mechanism is disclosed in more detail in U.S. Pat. No. 7,735,612, which is incorporated herein by reference for the purpose of teaching the operation of a ball ramp actuating mechanism. 
     Stationary plate  20  is secured to axle housing  12  by a plurality of mounting bolts  56 . A plurality of threaded channels  62  are provided in stationary plate  20  and are adapted to receive a portion of mounting bolts  56  therein. Axle housing  12  includes a mounting flange  58  extending radially outward therefrom, and mounting flange  58  includes a plurality of holes  60  therethrough adapted to receive mounting bolts  56 . The number of threaded channels  62  provided in stationary plate  20  is equal to the number of mounting bolts  56  and holes  60  provided, and threaded channels  62  are adapted to align with holes  60 . In certain embodiments, mounting flange  58  may include four holes  60 , each hole  60  receiving a mounting bolt  56  therein. However, it will be appreciated by those skilled in the art that more or less mounting bolts may be used. 
     A mounting sleeve  64  is positioned on one side of mounting flange  58  opposite brake  10 . Mounting sleeve  64  includes a plurality of mounting holes  66  adapted to receive mounting bolts  56  therethrough. The number of mounting holes  66  through mounting sleeve  64  is equal to the number of holes  60 , threaded channels  62  and mounting bolts  56  provided. Mounting bolts  56  include a threaded portion  68  and a head  70  positioned on opposing ends. Mounting bolts  56  extend through mounting sleeve  64 , mounting flange  58  and into threaded channels  62 . 
     The threaded portion  68  of mounting bolts  56  allows the bolt to be tightened, at head  70 , to secure brake  10  to axle housing  12 . While mounting sleeve  64  may be provided in a variety of forms, it is contemplated that the mounting sleeve may be provided in two portions: a first portion  72  and a second portion  74  ( FIG. 4 ). Providing mounting sleeve  64  in two portions facilitates easy installation around axle housing  12 , as will be appreciated by those skilled in the art. 
     The inclusion of mounting sleeve  64  allows the head  70  of mounting bolts  56  to be displaced from mounting flange  58 . This displacement alleviates the need to provide a flat portion on the outer radial surface of head  70 , as is required in conventional braking systems adapted to be secured to an axle housing flange as shown in  FIG. 1 . The inclusion of threaded channels  62  in stationary plate  20  alleviates the need for nuts positioned internally of stationary plate  20 , as shown in  FIG. 1  and as included in prior art designs. This distinction is significant in that it allows for use of a wet brake including lubricating and cooling fluid within an inner chamber without causing difficulties during installation and removal of the brake  10  from the axle housing  12 . 
     The brake  10 , axle  14  and hub  16  assembly may further include an end cap  80  that is received within an opening in hub  16 . End cap  80  includes a planar face  82 , a generally cylindrical body  84  and a flange  86  extending outwardly from the body  84 . Body  84  is received in an opening  88  in hub  16 . Flange  86  engages an annular lip  90  surrounding opening  88  to align and position the end cap  80  within the opening. End cap  80  may be secured within opening  88  by the vehicle wheel positioned on the lug bolts  18  of hub  16 . Flange  86  has a diameter that is larger than the standard diameter of the central opening through a wheel, thereby preventing it from passing therethrough. Alternatively, mechanical fasteners (not shown) may be used to secure end cap  80  within opening  88  of hub  16 . An annular O-ring  92  is provided within an annular channel  94  on a exterior surface of body  84 . O-ring  92  creates a seal between body  84  and an interior surface of opening  88 . Thus, water is prevented from entering the spline of hub  16  and traveling to the interior components of the brake. 
     The interior of body  84  of end cap  80  may include a casted pocket  96  that encompasses a nut  98  received on a threaded end  99  of the axle  14 . The casted pocket  96  includes a flat surface that aligns with one of the flat surfaces on the outer radial surface of the nut  98 . Thus, nut  98  is prevented from rotating relative to end cap  80  and axle  14 . 
     As shown in  FIG. 7 , brake  10  may also include a parking brake actuating mechanism  110  that is adapted to actuate the brake and apply a braking force to hub  16 . It should be appreciated that parking brake actuating mechanism  110  is a second actuating mechanism that is provided along with the hydraulic cylinder assembly  53 . Actuating mechanism  110  includes a shaft  112  positioned in a bore  114 , which passes through both stationary plate  20  and cover plate  26 . A lever  116  is secured to an end of shaft  112  protruding from bore  114  adjacent to cover plate  26 . Lever  116  is secured to the vehicle&#39;s parking brake actuation assembly. 
     Lever  116  includes a tapered hole  118  that fits over a matching tapered journal  120  on the end of shaft  112 . A lever assembly nut  122  is received on the end of shaft  112  on the outside of lever  116  and, when tightened, acts to secure lever  116  on shaft  112 . Tapered hole  118  and tapered journal  120  provide infinite lever location and adjustment for the parking brake feature. Lever  116  may be rotated to a specific orientation on shaft  112  and, when lever assembly nut  122  is tightened on shaft  112 , lever  116  is fixed in place by the interaction of tapered hole  118  and tapered journal  120 . A slot  124  is provided in the end of shaft  112  between lever  116  and lever assembly nut  122 . Slot  124  provides a mechanism by which shaft  112  may be held stationary while adjustment is made to lever  116  and lever assembly nut  122 . Slot  124  is concealed by an O-ring plug  126  and is positioned within the shaft  112 . 
     A lobe  128  is pre-assembled to shaft  112  opposite lever  116 . Lobe  128  engages an arm  130  on rotatable actuator  52 . As will be appreciated by those skilled in the art, rotation of lever  116  by the vehicles parking brake actuating mechanism causes rotation of shaft  112  and lobe  128 . Rotation of lobe  128  causes rotation of arm  130 , thereby rotating rotatable actuator  52  to actuate brake  10  and generate a braking force on hub  16 . 
     It is thus evident that a brake constructed as described herein accomplishes the objects of the present invention and otherwise substantially improves the art.