Patent Application
20230056307
The present invention relates generally to portal wheel ends for lifting the wheels of an off road vehicle, such as an all-terrain vehicle (ATV) or a utility task vehicle (UTV), and more particularly to gear-reducing portal gear boxes.
Portal gear lifts are used by ATV and UTV enthusiasts to raise an off-road vehicle higher above the ground so that larger tires can be run on the vehicle. In addition, since larger diameter tires cover a greater distance with each rotation, portal gear lifts typically include gear reduction so that a single rotation of the vehicle power axle results in a slightly lesser rotation of the output axle. Further, the extra length provided by the output axle may allow the assembly to widen the wheelbase of the vehicle.
Portal gear lifts typically include sealed housings (boxes) that contain a fluid lubricant effective to lubricate the gears as the gears spin within the housing. Vigorous use may cause the gears and their lubricant to heat, and that heating may reduce the effectiveness of the lubricant and cause pressure to build up within the housing. Additionally, excess heat may damage seals, causing them to fail and allowing oil, etc., to leak from the box.
A need therefore exists for materials and methods for reducing portal gear box heating, and for avoiding, reducing, and/or relieving resulting pressure. The present invention addresses that need.
In one aspect of the invention there is provided a portal gear box assembly for an all-terrain vehicle or a utility task vehicle. The assembly may comprise a sealed portal gear box housing having an interior housing space defined by a rear wall, a front wall, and a side wall. The rear wall may include a vehicle axle opening for receiving the end of the stock vehicle axle, and the front wall may include an output shaft opening for receiving the end of an output shaft that powers the vehicle wheel. A set of gears is housed in the housing, and the gears are effective for linking the axle received in the vehicle axle opening to the output shaft received in the output shaft opening. Thus, the output shaft is operably connectable via the linking mechanism to the axle, and provides the appropriate gear reduction for the vehicle as configured.
To reduce pressure build-up in the gear box housing, the assembly further includes an expandable space in fluid communication with the interior housing space. The expandable space is adapted to allow pressurized fluid contained in the interior housing space to flow into the expandable space, thus expanding the volume of the expandable space and reducing the pressure within the interior housing space. In some embodiments the expandable space comprises a bellows whose volume can be changed by expansion or contraction of a fluid contained therein.
The expandable space may be mounted externally to the portal gear box housing. Most preferably, the expandable space is connected to the portal gear box housing by a conduit effective for allowing fluid to pass between the portal gear box housing and the expandable space.
A fluid is contained within the portal gear box housing and within the expandable space. In some preferred embodiments that fluid comprises air.
The expandable space and its connecting conduit may be adapted to allow air pressure within the portal gear box housing to be relieved by expansion of the interior volume of the expandable space. Accordingly, the expandable space and its connecting conduit are effective for allowing air to flow from within the portal gear box housing to the expandable space when an increased air pressure within the portal gear box is encountered, thus mitigating against a build-up of air pressure within the portal gear box housing.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to certain embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the described device, and such further applications of the principles of the invention as illustrated therein, being contemplated as would normally occur to one skilled in the art to which the invention relates.
As indicated above, one aspect of the present invention relates to a vehicle such as an all-terrain vehicle or a utility task vehicle, and more particularly to a gear lift assembly for such vehicles. The assembly may comprise a sealed portal gear box housing having an interior housing space defined by a rear wall, a front wall, and a side wall. The rear wall may include a vehicle axle opening adapted to receive the end of an axle of an all-terrain vehicle or a utility task vehicle, and the front wall may include an output shaft opening adapted to receive the end of an output shaft that is effective to power a vehicle wheel. A set of gears is housed in the housing, and the gears are effective for linking the axle received in the vehicle axle opening to the output shaft received in the output shaft opening. Thus, the output shaft is operably connectable via the linking mechanism to the axle, and provides the appropriate gear reduction for the vehicle.
The assembly further includes an expandable space in fluid communication with the interior housing space. The expandable space is adapted to allow pressurized fluid contained in the interior housing space to flow into the expandable space, thus expanding the volume of the expandable space and reducing the pressure within the interior housing space. In some embodiments the expandable space comprises a bellows whose volume can be changed by expansion or contraction of a fluid contained therein.
The expandable space may be mounted externally to the portal gear box housing. Most preferably, the expandable space is connected to the portal gear box housing by a conduit effective for allowing fluid to pass between the portal gear box housing and the expandable space.
A fluid is contained within the portal gear box housing and within the expandable space. In some preferred embodiments that fluid comprises air.
The expandable space and its connecting conduit may be adapted to allow air pressure within the portal gear box housing to be relieved by expansion of the interior volume of the expandable space. Accordingly, the expandable space and its connecting conduit are effective for allowing air to flow from within the portal gear box housing to the expandable space when an increased air pressure within the portal gear box is encountered, thus mitigating against a build-up of air pressure within the portal gear box housing.
Referring now to the drawings,
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While the invention has been illustrated and described in detail in the foregoing description and drawings, the same are to be considered as illustrative and not restrictive in character, it being understood that only certain preferred embodiments have been shown and described, and that all changes and modifications that come within the spirit of the invention are desired to be protected.
Additionally, it is to be appreciated that the present invention may comprise or consist essentially of any or all of the described ingredients in their disclosed amounts, and that any or all of the ingredients, amounts, features, elements, and/or embodiments disclosed herein may be combined with any or all of the other ingredients, amounts, features, elements, and/or embodiments disclosed herein to provide an invention that comprises or consists essentially of such ingredients, amounts, features, elements, and/or embodiments.
The grammatical device “and/or” (such as in “A and/or B”) is used in this disclosure to mean A alone, or B alone, or both A and B. Additionally, the term “substantially perpendicular” means within 5° of perpendicular, and the term “substantially forward” (or rearward) of perpendicular means at least 10° forward (or rearward) of perpendicular.
