Abstract:
A liquid cooled brake system for motor vehicles. A mounting bracket having a plurality of mounting members is adapted to be fixedly mounted to an axle spindle assembly. The mounting bracket is adapted to support at least a first stator, a rotor, and at least one caliper assembly. The stator includes a cavity for carrying the cooling liquid that may include a plurality of flow obstacles to reduce the cooling liquid flow velocity so as to enhance the cooling capacity of the system. The stator may also incorporate a plurality of heat sink structures arranged about the stator.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a vehicle brake apparatus and, in particular, is comprised of a fluid cooled, circular brake pad arrangement that allows for the increased dissipation of heat for heavy duty braking applications. 
     2. Description of the Related Art 
     A typical automotive disk brake includes a circular rotating member called a rotor that is attached to a wheel hub assembly. The rotor and wheel hub are mounted on an axle shaft or spindle of the vehicle via bearings so as to rotate about the axle shaft or spindle. The rotor typically consists of a large diameter flat plate which forms a disk body. The typical disk brake assembly also includes a caliper that has a bracket defining an opening that fits over the outer edge of the rotor. Brake pads are positioned on the inner walls of the opening in the caliper such that a brake pad is positioned adjacent either side of the rotor. The caliper is typically hydraulically, pneumatically or electrically operated such that the pads are urged towards each other to engage with the rotor to slow the speed of rotation of the rotor. 
     The frictional forces exerted by each pad against each flat metal surface of the rotor will ultimately bring the rotor with attached wheel to a stop, thereby stopping the vehicle. The frictional effect of the pad surface engaging the rotor metal surface creates heat energy that can be dissipated out of the disk brake assembly through a plurality of metal cooling fins that are typically integral to the rotor. The majority of the heat generated by the braking action is dissipated, if at all, through the rotors with very little dissipation of this heat occurring via the brake pad or the caliper because the coefficient of thermal conductivity of the pad is considerably smaller than that of the metal rotor. 
     The vehicle&#39;s pads and rotors typically have a finite life expectancy. Repeated, hard brakings in stop and go traffic will not allow the brake system to dissipate all the generated heat which causes premature wear on the pads as well as on the rotors. High temperature heating of the rotors contributes to a scoring and glazing of the rotor and pad surface which can reduce the braking effectiveness of the vehicle. Moreover, this heat can cause the rotor to warp over time. 
     The premature wear pattern and performance limitation of the conventional disk brake system dictate a need for a braking concept that can accommodate more rigorous braking situations. To address these needs, alternative disk brake configurations have been developed. 
     For Example U.S. Pat. No. 4,508,299 to Cigognini discloses a braking system that includes a rotating rotor with a braking head assembly that has a plurality of cooling passages provided therein. The braking head assembly frictionally engages with the rotating rotor so as to slow the rotating rotor to thereby brake the vehicle. The existence of cooling passages in the braking head assembly increases the cooling capacity of the Cigognini brake assembly and thereby reduces wear on the rotor. 
     While the Cigognini reference discloses a brake assembly that has improved cooling capacity, the Cigognini brake assembly is difficult to mount and provides only limited cooling capacity. In particular, the movable brake head in the Cigognini assembly is mounted adjacent the rotor via one or more rods that are apparently attached to the frame of the vehicle and extend toward the rotor so as to retain the brake head in proximity to the rotor. This mounting structure requires the installer to mount the rods to the frame of the vehicle which is not always possible with some vehicle configurations. Moreover, due to the relative length of the rods, the braking assembly is more prone to damage and is expensive to manufacture. Further, due to the relative complex mounting assembly for the brake heads, this mounting arrangement makes it difficult for the brake heads to be positioned about more than a limited amount of the circumference of the rotor which results in less braking capability as there is limited surface area of the brake head in contact with the rotor. 
     Even more significantly, the Cigognini design does not permit the brake assembly to be used in conjunction with brake assemblies that are mounted adjacent movable spindles. In particular, the movable brake head in the Cigognini design moves as a result of actuation of the fixed length rods. Since these rods are permanently attached to the frame of the vehicle, this system cannot be used with brakes on swiveling spindles as the rods do not accommodate any movement of the brake head relative to the rods. Hence, the Cigognini design could not be used on standard automobile front brake systems as the front brakes are attached to swiveling spindles which allow the vehicle to be steered. 
     It will be appreciated that the majority of braking power that is applied to automobiles and trucks is applied to the front brakes. Consequently, the front brakes are the brakes that are most likely to suffer from excessive heating. The Cigognini design is thus not well suited for use with automobiles, trucks and the like as it cannot be used to cool front brake assemblies that provide the majority of braking for these types of vehicles. 
     Further, while Cigognini discloses a cooling chamber in the brake head, the fluid in the brake head can flow unimpeded through the brake head. The cooling fluid may therefore be isolated to limited areas of the brake head due to forces on the vehicle during braking. This can lead to isolated areas of the brake head being cooled at different rates than other areas which can, over time, result in damage to the brake head or the rotor. Moreover, the cooling fluid may have to be circulated through the passageway at a faster rate which thereby decreases the efficiency of the heat transfer to the cooling fluid. This can result in limiting the cooling of the brake assembly causing the problems discussed above. 
     From the foregoing, it will be appreciated that there is a continuing need for brake systems that can provide better brake performance and improve the longevity of the brake components. To this end, there is a continuing need for brake systems with better cooling capability that are less expensive and easier to mount to existing vehicles. More particularly, there is a need for a system for cooling brake components that can be adapted for use with brake assemblies that are movable with respect to the frame of the vehicle, such as the brake assemblies on the front wheels of road vehicles. 
     SUMMARY OF THE INVENTION 
     The aforementioned needs are satisfied by the brake assembly of the present invention which, in a first aspect, is comprised of a brake assembly having a mounting bracket that is adapted to be positioned about the axle or spindle of a vehicle wherein the mounting bracket has a plurality of arms that extend radially outward from the axle or spindle of the vehicle, a rotor assembly that is rotatably attached to the axle or spindle of the vehicle, and at least one stator that is attached to the mounting arms of the mounting bracket so as to be slidable in a direction that is parallel to the axis of the vehicle axle or spindle such that the at least one stator can engage with the rotor to thereby slow the angular rotation of the rotor wherein the at least one stator is liquid cooled to remove heat generated by the frictional engagement between the rotor and the at least one stator. The assembly further comprises a caliper that defines a cavity that fits around at least a portion of the outer perimeter of the at least one stator and the rotor such that activation of the caliper will result in lateral movement of the stator along the direction of the axis of the axle such that the at least one stator can engage the rotor. 
     Hence, in this aspect, the brake assembly allows for the use of liquid cooled stators which are better able to remove ambient heat away from the rotor to improve brake performance. Moreover, since the stators are slidably mounted to the mounting arms of the mounting bracket such that the stators can move slidably along pins or guides in a direction that is parallel to the axis of the axle or spindle, installation of the brake assembly is simplified. 
     In one particular embodiment, two stators are slidably mounted to pins that are positioned on the mounting arms of the mounting bracket such that the rotor can be interposed between two stators. In one implementation, the rotor comprises two circular friction disks attached to the rotor at the stator interface. A caliper assembly can then be positioned about the outer perimeter of the stators such that the stators can be urged inward so as to contact the rotors. In one embodiment, a plurality of mounting arms extend radially outward from the center of the mounting bracket such that a plurality of sliding posts can be positioned about the outer perimeter of the rotor to thereby permit uniform slidable connection points for each of the stators. In this embodiment, a plurality of calipers can thus be used to urge the stators towards the rotor to thereby halt the rotational motion of the rotor. 
     As the stators are liquid cooled, the stators can remove a greater amount of heat energy occurring as a result of the stators frictionally engaging with friction material positioned on the rotor. In one aspect, each of the stators has channels formed therein that have flow inhibiting structures positioned so as to extend in a direction generally perpendicular to the flow of the cooling fluid to thereby slow the rate of the cooling fluid to allow for greater transfer of heat to the cooling fluid. In another aspect, the cooling fluid is pumped to a cooling reservoir and the stators are also equipped with cooling fins to thereby increase the cooling of the stators to improve the removal of heat from the brake assembly. 
     It will be appreciated that the brake assembly is better able to remove heat than non-cooled brake assemblies of the prior art and are easier to mount than existing cooled brake assemblies of the prior art. Moreover, since the assembly is mountable via a bracket to the spindle of the vehicle, the brake assembly can be mounted on swivelable front wheels of vehicles thereby permitting cooling of the front brakes of vehicles which typically account for the majority of braking power applied to the vehicle and are more in need of increased cooling capacity. These and other objects and advantages of the present invention will become more fully apparent from the following description taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a vehicle illustrating a wheel attached to a vehicle; 
     FIG. 2 is an exploded perspective view of one embodiment of a brake system of the present invention; 
     FIG. 3 is a perspective view of the brake system of FIG. 2 in an assembled configuration; 
     FIG. 4 is a perspective view of the brake system mounting bracket attached to a vehicle front spindle; 
     FIG. 5A is a cross sectional view of a single stator of the brake system of FIG. 2 illustrating the fluid channel cavity with the respective fluid flow direction; 
     FIG. 5B is a side or perspective view of the stator of FIG. 5A illustrating cooling fins extending in a radial outward pattern on the outward surface of a stator; 
     FIG. 5C is a side or perspective view of the stator of FIG. 5A illustrating cooling fins extending circumferentially around the outer surface of the stator; and 
     FIG. 6 is a schematic view of the brake assembly of FIG. 2 illustrating a rotor positioned between a first stator, a second stator and the series fluid cooling circuit comprising a fluid pump and fluid cooling reservoir. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made to the drawings wherein like numerals refer to like parts throughout. FIG. 1 illustrates the wheel assembly of a vehicle  100 . The vehicle has a typical tire and wheel assembly, wherein the vehicle tire  102  is mounted to a wheel  104  and the wheel  104  is attached to a wheel hub assembly. A plurality of wheel lugs  106  are used to secure the vehicle tire  102  with the attached wheel  104  to the wheel hub assembly in a well-known manner. As is understood in the art, a brake assembly is generally attached to the wheel hub assembly such that activation of the brake assembly results in the frictional forces being applied to slow the rate of rotation of the wheel hub assembly and the wheel  104  with the tire  102 . 
     In this embodiment, a fluid cooled brake assembly  150  (FIG. 2) is attached to the wheel hub assembly and can therefore be used to slow the rotation of the wheel  104 . It will be appreciated from the following description that the cooled brake assembly  150  can be adapted for use in conjunction with any wheels of a vehicle, including front, rear or intermediate wheels, and can further be adapted for use with driving and non-driving wheels of the vehicle without departing from the spirit of the present invention. 
     Referring now to FIGS. 2 and 3, the exploded view of the components of one embodiment of a fluid-cooled brake system  150  is illustrated. In particular, the brake system  150  includes a circular first stator  112  and a circular second stator  114 . The first stator  112  has a first opening  113  that is approximately ⅔ the diameter of the first stator  112 . The second stator  114  also has a circular, second opening  115  which is ⅔ the diameter of the second stator  114 . The first stator  112  and the second stator  114  are approximately 0.625 inch in thickness and are both slidably mounted to a mounting bracket  152  in a manner that will be described in greater detail below. 
     Located between the first stator  112  and the second stator  114  is a circular shaped metal rotor  116  with a thickness of approximately 0.625 inch. The rotor  116  and the stators  112 ,  114  are preferably centered about a first axis of rotation  120 . As will be described in greater detail below, the rotor  116  rotates about the first axis of rotation  120  between the first stator  112  and the second stator  114  and has friction material  119  positioned on the front and rear faces of the rotor  116  in the manner shown in FIG.  2 . 
     A mounting bracket  152  is mounted to the vehicle axle or spindle assembly, wherein an axle spindle  214  with a threaded end  216  extends through a first opening  158  of the mounting bracket  152 . The mounting bracket  152  is attached to a mounting plate  300  that is typically part of the original equipment of the vehicle. The mounting plate  300  has an opening  302  through which the axle spindle  214  extends therethrough. The plate also has a plurality of openings  304  that are spaced about the plate to permit attachment of the mounting bracket  152  allowing the brake calipers to be secured to the vehicle. The mounting bracket  152  is adapted to make use of the openings  304  to be secured about the axle or spindle of the vehicle. Because the mounting bracket  152  is mounted directly to the mounting plate  300 , if the spindle is movable, the bracket  152  will move with the spindle. Hence, the mounting bracket  152  can be mounted on the steering wheels of a vehicle. 
     The mounting bracket  152  includes the bracket members  154 ,  156  and  160  that extend radially outward from the center of the bracket  152 . Each bracket member  154 ,  156 , and  160  extends outward in a plane parallel to the second stator  114  and the first stator  112  with a length approximately equal to the radius of the first stator  112  and the second stator  114 . 
     A plurality of metal dowel pins or slides  154   a,    154   b  through  160   a,    160   b,  each approximately 2.25 inches in length and 0.25 inch in diameter, are fastened to the mounting bracket members  154  through  160  respectively. In particular, the dowel pins  154   a,    154   b  through  160   a,    160   b  are positioned at the outer edge of each of the bracket members  154 ,  156 , and  160 , respectively, and extend perpendicularly outward from the plane of the mounting bracket  152  so as to extend in the direction of the axis  120 . The pins or slides define a mounting location for the stators  112 ,  114  as will be described in greater detail hereinbelow. 
     As is also illustrated in FIGS. 2 and 3, the second stator  114  includes mounting flanges  200  through  212  located at the outer perimeter that are adapted to engage with the dowels  154   a,    154   b,    156   a,    156   b  and  160   a,    160   b  so that the second stator  114  can be slidably mounted on the mounting bracket  152 . In particular, the second stator  114  is attached to the bracket  152 , so that the rear surface  198  of the second stator  114  is adjacent the mounting bracket  152 . The dowel pin  154   a  of the first bracket member  154  inserts through the second stator mounting flange hole  200   a.  The dowel pin  154   b  of the first bracket member  154  inserts through a second stator mounting flange hole  202   a.  The dowel pin  156   a  inserts through a second stator mounting flange hole  204   b  and the dowel pin  156   b  inserts through a second stator mounting flange hole  206   a.  The dowel pin  160   a  inserts through a second stator mounting flange hole  210   a,  and the dowel pin  160   b  inserts through a second stator mounting flange hole  212   b.  In this way, the second stator  114  can be easily mounted to the mounting bracket  152 . 
     As is also illustrated in FIG. 2, the rotor  116  includes a rear rotor surface  174  and a front rotor surface  172  that engages with the stators  112 ,  114  respectively so as to provide braking of the vehicle in a manner that will be described in greater detail below. Both the front and rear rotor surface  172 ,  174  are preferably covered with a friction material such as is commonly used in the art. The rotor  116  is generally disk shaped and has dimensions that are approximately equal to the dimensions of the stators  112 ,  114 . As is also illustrated in FIGS. 2 and 3, the rotor  116  includes an extending assembly  170  that is adapted to permit attachment of the wheel onto the rotor  116  via a plurality of lugs or bolts  106 . The rotor  116  is attached to the spindle  214  via a well-known bearing assembly  222  in a manner that will be described in greater detail hereinbelow. 
     As is also shown in FIGS. 2 and 3, the first stator  112  is generally circular in shape with a circular opening  113  positioned in the center. The first stator  112  also includes a plurality of mounting flanges  182 ,  184 ,  186 ,  190 ,  192  and  194  that each have two openings formed therein where one of the openings receives the slides  154   a,    154   b  through  160   a,    160   b  and the other opening receives the bolts  308  that secure the calipers  162 ,  164 ,  166  to the assembly in a manner that will be described in greater detail below. The openings  182   a,    184   a,    186   b,    190   a    192   a  and  194   b  are adapted to receive the dowels  154   a,    154   b,    156   a,    156   b,  and  160   a,    160   b,  respectively, of the mounting bracket  152  so that the stator  112  can also be slidably mounted to the bracket  152  with the rotor  116  interposed between the first stator  112  and the second stator  114  in the manner shown in FIG.  3 . The opening  113  in the first stator  112  is preferably sized so that the wheel extender  170  of the rotor  116  extends through the opening  113  of the first stator  112  to permit the wheel  104  to be attached thereto. 
     The assembly  150  also includes a known wheel bearing  220  that is coupled to the axle spindle  214 . In particular, a hub assembly  222  of the bearing assembly  220  is screwed onto the threaded end  216  of the axle spindle  214  to rotatably capture the rotor  116  to the axle spindle  214  in a well-known manner. The wheel hub extender  170  is attached to the rotor  116  and defines a location to which the wheel  104  can be mounted to the rotor  116 . As the rotor  116  is rotatably mounted to the axle spindle  214 , the wheel  104  is thus rotatably mounted to the vehicle thereby permitting rolling motion of the vehicle over the ground. It will be appreciated that while the rotor assembly  116  includes a wheel hub extender, the improved brake assembly of the present invention can be used in conjunction with rotor assemblies that do not have such wheel hub extenders without departing from the spirit of the present invention. 
     In this particular embodiment, a first caliper  164 , a second caliper  166 , and a third caliper  162  are secured to an outer edge surface of the first stator  112 , the rotor  116 , and the second stator  114  so as to be spaced about the outer perimeter of the stators  112 ,  114  and rotor  116 . The calipers  162 ,  164  and  166  are similar to existing calipers in the art and each has an inner cavity  162   a,    164   a  and  166   a.  A hydraulically, pneumatically or electrically activated clamping mechanism is located within the cavities  162   a,    164   a  and  166   a  such that application of the brakes results in a decrease in the width of the cavities  162   a,    164   a  and  166   a.  As is illustrated in FIG. 3, each of the calipers  162 ,  164  and  166  are positioned about the first stator  112 , the second stator  114  and the rotor  116  such that an outer edge of each of the first stator  112 , the rotor  116  and the second stator  114  are positioned within the cavities  162   a,    164   a  and  166   a  of the calipers  162 ,  164  and  166  respectively. Hence the clamping mechanism within each of the calipers  162 ,  164  and  166  result in the stators  112 ,  114  being urged against the surfaces of the rotor  116  in a manner that will be described in greater detail below. 
     In particular, the dowel pins  154  through  160  on the bracket mounting member  152  are adapted to maintain the first stator  112  and the second stator  114  in alignment with the spinning rotor  116  while permitting the stators  112 ,  114  to slide along the dowels in the direction of the axis  120  in response to clamping by the calipers  162 ,  164 ,  166 . The first stator  112  and the second stator  114  thus exert an inward force, perpendicular to the plane of the rotor  116  and in the same plane as the first axis of rotation  120 , wherein these equal, but opposing, inward forces act to squeeze the rotor  116  thereby slowing the angular motion of the rotor  116  and the resultant linear motion of the vehicle. 
     FIG. 3 illustrates a perspective view of the brake system  150  components of FIG. 2 in an assembled state. The first caliper  164  and the second caliper  166  are shown in a final assembled position positioned about the combination of the first stator  112 , the rotor  116 , and the second stator  114 , wherein the first caliper  164 , the second caliper  166  and the third caliper  162  are used to apply a concurrent inward force on the first stator  112  and the second stator  114  so as to move the stators  112 ,  114  inward toward each other along the dowels so as to exert a frictional force against the rotor  116 . These combined and opposing forces against the rotor  116  act to slow or stop the angular motion of the rotor  116  which is attached to the wheel rim  104  and consequently stopping the forward or reverse movement of the vehicle  100 . 
     A perspective view of the brake system  150  mounting bracket  152  is illustrated in FIG.  4 . The axle spindle  214  can be seen extending outward perpendicular to the first member  154 , the second member  156 , and the third member  160  of the mounting bracket  152 . The mounting bracket  152  is mounted on the spindle assembly  214  such that the spindle extends through a central opening  158  in the mounting bracket  152 . As discussed, above, the bolts  308  extend through the openings  182   b,    184   b,    186   a,    190   b,    192   b,    194   a  in the first stator  112  and through the openings  200   b,    202   b,    204   a,    206   b,    210   b,  and  212   a  in the second stator  114  and into the apertures  307  on the calipers  162 ,  164 ,  166  respectively. The bolts  308  have a threaded portion  309  that engage with the stator  112  and a non-threaded portion  311  that provides a surface upon which sliding of the stator  114  can occur. In this way, the calipers  162 ,  164  and  166  can be mounted to the assembly such that the brake assembly can be actuated regardless of the orientation of the brake assembly during turning of the vehicle. 
     The spindle or axle of the vehicle defines a mounting point for the assembly such that if the mounting point is a spindle that is swivelable with respect to the vehicle, e.g., it is the spindle of a movable steering wheel of the vehicle, and the plate  300  is attached to the spindle in this manner, the assembly will move with the spindle. In particular, because the mounting bracket  152  mounts so as to be centered about the spindle  214 , the mounting brackets can define the connection points for the stators  112 ,  114  that are centered about an axis  120  defined by the spindle  214 . Hence, the mounting bracket  152  provides an easy system for mounting the brake assembly  150  to a vehicle and allows the assembly to be used on movable wheels of the vehicle, such as front wheels used to steer the vehicle. Moreover, since the calipers  162 ,  164  and  166  are clamp calipers that are positioned about the outer perimeter of the stators  112 ,  114  the installation of the brake system  150  is greatly facilitated. 
     FIG. 5A is a cross-sectional view representing the interior configuration of either of the stators  112 ,  114 . As illustrated, a continuous inner cavity  230 ,  230   a-c  occupies a substantial volume of the stators  112 ,  114  and is capable of carrying heat transfer fluid therethrough to cool the brake assembly  150 . The continuous inner cavity  230 ,  230   a-c  of the stators  112 ,  114  is interrupted by a plurality of fluid flow obstacles  232 ,  232   a-d  wherein the fluid flow obstacles  232 ,  232   a-d  are purposely formed when the first stator plate  112  is machined or cast. In particular, the continuous inner cavity  230 ,  230   a-c  extends generally circumferentially around the stators  112 ,  114 . As will be described in greater detail below, cooling fluid is introduced at an input port  136  and travels around the cavity  230 ,  230   a-c  in the direction of the arrows towards an output port  140 . A plurality of flow obstacles  232 ,  232   a-d  are positioned about the circumferential flow cavity  230 ,  230   a-c  so as to extend generally perpendicularly into the direction of flow of the cooling fluid between the input port  136  and the output port  140 . Hence, the flow obstacles  232 ,  232   a-d  slow down and control the rate of flow of the fluid between the input port  136  and the output port  140 . 
     A reduction in cooling fluid flow provides the fluid additional time to allow the transfer of heat from the surrounding area of the inner stator surface of the stators  112 ,  114  to the fluid, thereby improving the efficiency in heat transfer. As shown in FIG. 6, this additional heat energy is continually and sequentially carried out from the first stator plate  112  through a fluid line  130  to the second stator  114 , through the second stator  114 , through a return fluid line  132  to a fluid reservoir-cooler  124 . A pump  122  is used to circulate the fluid through the fluid reservoir/cooler  124  and the stators  112 ,  114 . It will be appreciated that the fluid reservoir/cooler  124  may actually be comprised of the engine radiator and radiator coolant is circulated through the brake assembly from the radiator. It will be appreciated that the transferred heat is dissipated and cooled in the fluid reservoir-cooler  124  providing a more efficient and productive fluid-cooled braking system  150 . While the schematic of FIG. 6 illustrates that the cooling fluid from one stator is provided to a second stator in a serial fashion, the cooling fluid can also be independently provided from the cooling reservoir directly to the different stators without departing from the spirit of the present invention. 
     Another embodiment of the stators  112 ,  114  is illustrated in FIG.  5 B. As illustrated, a plurality of cooling fins  240 ,  240   a-g  extend in a radial outward pattern on the front stator surface  176  of the first stator  112 . Each cooling fin  240 ,  240   a-g  is a rectangular bar of metal equally spaced from each other, whereas one end of the cooling fin  240 ,  240   a-g  extends from the edge of the opening  113  of the stators  112  radially outward to the edge of the outer surface  176  of the stator  112 . The plurality of cooling fins  240 ,  240   a-g  act as a large heat sink, wherein convection cooling allows the heat generated in the braking components to be transferred to the surface area of the cooling fins  240 ,  240   a-g  and dissipated to the circulating air past the wheel assembly during forward movement of the vehicle. 
     FIG. 5C illustrates another embodiment of the stators  112 ,  114 . As is illustrated, a plurality of cooling fins  241  extending in a circumferential pattern is formed on the front stator surface  176  of the first stator  112 . Each cooling fin  241  is a generally rectangular bar of metal that creates a heat sink that further facilitates cooling of the brake assembly  100 . It will be appreciated that any of a number of different configurations of cooling fins can be used on the stators to increase the cooling capacity of the brake assembly  100  without departing from the spirit of the present invention. 
     In one embodiment, the coolant system of FIG. 6 is adapted to be able recirculate coolant fluid through the brake assembly  150  during periods when the brakes are not being used. This allows for the cooling fins to cool the coolant fluid thereby increasing the overall cooling capacity of the vehicle. It will be appreciated that if the fluid reservoir is the vehicle radiator, and the vehicle is travelling uphill, being able to circulate the coolant through the stators  112 ,  114  that have cooling fins attached thereto in the manners shown in FIG. 5B and 5C improves the ability of the vehicle to cool the coolant and avoids overheating of the vehicle radiator. 
     Hence, the brake assembly  150  provides an assembly that includes stators  112 ,  114  that are liquid cooled and are thus capable of removing increased amounts of heat produced as a result of the stators  112 ,  114  engaging with the rotating rotor  116 . Moreover, the use of a mounting bracket  152  that is positioned about the axis of the axle allows for the stators to be slidable along pins that extend in the direction of the axis. Since the stators are slidable along the pins, clamp calipers can then be mounted about the stators and rotors to enable the stators to be urged into contact with the rotor to slow the rotor. Hence, the present configuration of the brake assembly  150  permits easier mounting of the brake assembly than cooled brake assemblies of the prior art and also allows the assembly to be used in conjunction with movable wheels of vehicles. 
     Moreover, the configuration of the liquid passages also greatly improves the efficiency of the cooling of the brake assembly thereby permitting the application of greater braking forces. The mounting arrangement permits the mounting of calipers about essentially the entire perimeter of the stators and rotors due to the use of the mounting bracket which allows for much greater braking forces to be applied. 
     It will be appreciated that since the stators are cooled, lighter weight stators can be used for braking purposes in the vehicle. This results in an overall reduction in the weight of the vehicle and also allows for the use of light weight standardized stators for different vehicles. 
     Although the foregoing description of the preferred embodiment of the present invention has shown, described and pointed out the fundamental novel features of the invention, it will be understood that various omissions, substitutions, and changes on the form of the detail of the apparatus as illustrated as well as the uses thereof, may be made by those skilled in the art without departing from the spirit of the present invention. Consequently, the scope of the present invention should not be limited to the foregoing discussions, but should be defined by the appended claims.