This invention relates to a brake especially adapted for use with all-terrain vehicles or over-the-road towed vehicles, such as boat trailers or the like. More specifically, this invention relates to such a brake wherein the components thereof are sealed from the environment.
Over-the-road trailers and all-terrain vehicles are normally provided with conventional single disc caliper brakes with, at times, being provided with drum brakes. As such, the components of these brakes are exposed to the atmosphere which readily results in the corrosion of many of their component parts. Such is particularly true in the case of boat trailers where the brakes are frequently exposed to water, even salt water. Such corrosion not only affects brake wear, efficiency, and consistency, but also will ultimately lead to the need to replace many critical, and expensive, brake components. Moreover, heat dissipation problems with these prior art brakes can affect brake performance and potentially lead to premature failure.
When a brake is sealed to the atmosphere, usually the components thereof are immersed in oil for cooling purposes. However, the oil must be sealed from the brake fluid used to operate the brakes of over-the-road trailers or all-terrain vehicles, which presents a problem of seal compatibility; that is, the seal material used for petroleum-based oil is incompatible with the brake fluid or vice-versa. The solution of the prior art to this problem is to provide two seals with an air gap between them which allows each fluid to interact only with the seal with which it is compatible. Such undesirably adds to the size and the cost of the brake.
In addition to the foregoing problems, the prior art brakes are difficult and time consuming to install and/or replace. With respect to trailers, first, a spindle must be welded onto the axle of the trailer and bearings must be pressed onto the spindle. Then a hub and disc, or hub and drum, assembly, with bearing races formed therein, must be attached to the spindle. Then a bracket must be mounted on the frame of the trailer and a caliper attached to the bracket adjacent to the disc. The wheel is then mounted to the hub. With respect to all-terrain vehicles, the caliper and wheel assembly must be mounted to the strut on the front of the vehicle. First, bearings must be installed into bores cut into the strut itself. Then, a shaft is installed into the bearings. The shaft is splined on the outside to accept the gear tooth configuration of a hub which mounts both the wheel and the rotor for the caliper. The caliper is mounted to a machined face of the strut by a separate bracket which allows the caliper to float on the disc.
In view of these problems, it is evident that the need exists for a modular brake which is easy to install and which will isolate all of the components of the brake from the deleterious effects of its environment.
It is thus an object of the present invention to provide a brake for a trailer or all-terrain vehicle which is modular in nature and which totally houses the brake components to seal them from the environment.
It is another object of the present invention to provide a brake, as above, which is easy to install.
It is a further object of the present invention to provide a brake, as above, in which the brake components are protected from corrosion.
It is an additional object of the present invention to provide a brake, as above, which provides consistent braking forces for the vehicle.
It is yet another object of the present invention to provide a brake, as above, which provides superior heat dissipation and otherwise prevents premature failure.
It is a still further object of the present invention to provide a brake, as above, in which the components thereof are immersed in oil and a single seal can be utilized between the activating brake fluid and the oil.
It is still a further object of the present invention to provide a brake, as above, in which the components will not disadvantageously wear, thereby providing a brake which will not normally need replacement or service.
These and other objects of the present invention, as well as the advantages thereof over existing prior art vehicle brakes, which will become apparent from the description to follow, are accomplished by the improvements hereinafter described and claimed.
In general, a brake for a wheel of a vehicle made in accordance with the present invention includes a housing, and an axle assembly adapted to be attached to the wheel of the vehicle for rotation therewith. A plurality of stationary discs are positioned in the housing. A plurality of rotatable discs are carried by the axle assembly and are positioned to be engaged by the stationary discs. At least one bracket is carried by the housing. Each stationary disc has at least one ear which is received in the bracket. A piston is moveable to cause the stationary discs to engage the rotatable discs to apply a braking torque to the wheel.
In accordance with another aspect of the present invention, the axle assembly includes drive surfaces which engage a shaft sleeve having a splined outer surface. The plurality of rotatable discs are carried by the splined outer surfaces.
In yet another aspect of the present invention, a first fluid is provided in the housing. The piston includes a ring and a rib and is moveable by a second fluid to cause the ring to engage a stationary disc to cause the stationary discs to engage the rotatable discs to apply a braking torque to the wheel. A seal is provided adjacent to the rib to prevent the first fluid from communicating with the second fluid.
In a further aspect of the present invention, the housing has open ends, and a plate is attached to one end of the housing and is adapted to be attached to the vehicle. A seal is provided between the plate and the housing. The axle assembly is received in the other end of the housing and a seal is provided between the housing and the axle assembly.
A preferred exemplary vehicle brake incorporating 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.