Patent Application
20070295158
The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which:
It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions, directions or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless the claims expressly state otherwise.
Referring now to
The drive axle assembly housing 10 has an upper portion 16, a lower portion 18 and a substantially hollow interior portion 20 (refer to
Preferably, the drive axle assembly housing 10 has an aperture 24 in the upper portion 16. While
Regardless of where it is located, the aperture 24 extends to the interior portion 20, as seen in
Turning now to
The horizontal portion 36 extends to a cap 48, or head, of breather 30. In the depicted embodiment of the invention, the cap 48, the substantially horizontal portion 36 and the substantially vertical portion 38 are integrally formed and one piece. The cap 48 preferably has a substantially planar upper surface 50. The planar upper surface 50 can be engaged with a hand or a tool to push the breather 30 into the aperture 24.
Preferably, the elbow 32 is constructed of a plastic or a reinforced resin. Either of these materials, or their equivalents, is preferred for the elbow 32 since at least the horizontal portion 36 and cap 48 will be located substantially outside of the drive axle assembly housing 10, thus exposing them to the driving environment under the drive axle assembly housing 10. Additionally, the elbow 32 needs to withstand the process for inserting the breather 30 into the aperture 24. It is also preferred that the material for the elbow 32 is resistant to both heat and cold since the drive axle assembly housing 10 can be exposed to temperatures ranging from −40° F. to 350° F.
As best seen in
A first baffle 54 is located at a transition area 56 between the horizontal portion 36 and the vertical portion 38 within the first passageway 52. Preferably, the first baffle 54 is integrally formed with the elbow 32. It is also preferred that the first baffle 54 extend into the first passageway 52 as a substantially continuous extension of a lower wall 58 of the horizontal portion 36.
The body portion 34 of the breather 30 is best seen in
The second passageway 62 preferably has a second baffle 72 and a third baffle 74 that both extend substantially perpendicularly to an inner wall 76 of the second passageway 62. The second baffle 72 and the third baffle 74 are vertically offset from one another and they extend into the second passageway 62 substantially opposing one another.
As best seen in
A bottom portion 82 of the body portion 34 is defined by a plurality of legs 84 where at least two of the legs 84 are unequal in length. The unequal length of the legs 84 can be seen in
Looking now at
The intermediate seals 90, which are preferably located within a reduced diameter portion 98 of the body portion 34, and which preferably number three, frictionally engage with the wall 28 that defines the aperture 24. Preferably, the outer diameter 100 of the intermediate seals 90 is slightly larger than the inner diameter 102 of the aperture 24 to assist the body portion 34 in frictionally engaging with the wall 28 that defines the aperture 24.
The lower seal 92 seals against an inner surface 104 of the interior portion 20 of the drive axle assembly housing 10. The lower seal 92 has an outwardly extending flange 106 that prevents the breather 30 from being unintentionally removed from the aperture 24.
The upper seal 88, the intermediate seals 90 and the lower seal 92 all prevent, or reduce, lubricant 22 from leaving the interior portion 20 or from exterior fluids from entering into the interior portion 20. The seals 88, 90, 92 are preferably arranged on the outside surface 96 of the body portion 34 from top to bottom in the following order: upper seal 88, intermediate seals 90, lower seal 92.
It can be appreciated based on the above-description that the breather 30 can be simply pushed into an aperture 24 in a drive axle assembly housing 10 without requiring the breather 30 to be threadably engaged with the aperture 24. It can also be appreciated that the breather 30, and its associated breather hose 44, can be inserted in the aperture 24 with the horizontal portion 36 pointed in any direction since the breather 30 is not dependent upon threads to secure it to the assembly housing 10.
Continuing now with a description of the body portion 34, it can be best seen in
Preferably, the body portion 34 is constructed of a rubber-like material. As the body portion 34, and in particular the above-described seals 88, 90, 92, will be in contact with the wall 28 that defines the aperture 24, the rubber-like material will assist in reducing vibration of the breather 30. The rubber-like material will also help the body portion 34 to resist movement within the aperture 24. It is preferred that the material for the body portion 34 is resistant to both heat and cold since the drive axle assembly housing 10 can be exposed to temperatures ranging from −40° F. to 350° F.
As best seen in
It can be appreciated that during high speeds and/or vibration, lubricant 22 may be splashed such that it moves up into the body portion 34 and occasionally moves past the third baffle 74. This does not occur frequently since the third baffle, which is substantially planar, deflects the lubricant 22 downwardly into the interior portion 20. The vertically offset and alternately opposing second baffle 72 creates another stop that reduces or prevents lubricant 22 from moving beyond it. It is a discovery of the present invention that lubricant 22 that moves past the third baffle 74 splashes, or tumbles, in the second lubricant tumble chamber 112 and it substantially does not move past the second baffle 72. It can be appreciated that the second baffle 72, which is substantially planar, deflects the lubricant 22 downwardly toward the third baffle 74, thus creating a tumbling effect. The lubricant is free to drain out of the bottom of the chamber 112.
Any lubricant 22 that does move past the second lubricant tumble chamber 112 is caught by the first lubricant tumble chamber 110. It can be appreciated that the first baffle 54, which is substantially planar, deflects the lubricant downwardly toward the second baffle 72, thus creating a tumbling effect. The lubricant is free to drain out of the bottom of the chamber 110. Lubricant 22 in the first lubricant tumble chamber 110 merely splashes, or tumbles, around and it substantially does not flow out of the first lubricant tumble chamber 110 past the first baffle 54.
The design of the baffles 54, 72, 74, also functions to burst any bubbles that may form in the lubricant 22. Bubbles can form whenever the vehicle is moving, but are most likely to form when the vehicle is operating at high speeds and/or in bumpy conditions. Whenever a bubble reaches a baffle 54, 72, or 74, it typically bursts upon impact.
It can be appreciated that despite the fact that lubricant 22 is prevented from escaping from the axle assembly housing 10 through the breather 30, air is free to communicate to and from the axle assembly housing 10. Specifically, air is substantially free at all times to communicate around the first baffle 54, through the first lubricant tumble chamber 110, around the second baffle 72, through the second tumble chamber 112, around the third baffle 74, and past the legs 84 of the body portion 34 to the interior portion 20 of the axle assembly housing 10 and vice versa.
It can also be appreciated based on the above-described path air must follow to communicate into and out of the interior portion 20, that the lubricant 22 cannot do the same. Specifically, the lubricant 22 first must be splashed not just onto, but actually into, the second passageway 62. If the lubricant 22 is splashed into the second passageway 62, the length of the second passageway 62 from the legs 84 to the third baffle 74 may be too long for the lubricant 22 to traverse.
If the lubricant 22 does traverse the second passageway 62 to the third baffle 74, the planar nature of the baffle 74 will re-direct the lubricant 22 back toward the interior portion 20. Should lubricant avoid the third baffle 74, it cannot travel vertically through the second passageway 62 very far before coming in contact with the second baffle 72, as can be appreciated based on
The lubricant 22 would then have to travel upwardly so as to move past the second baffle 72. If the lubricant 22 continued to travel upwardly, so as to enter the first passageway 52, it would encounter the first baffle 54. The first baffle 54 would likely re-direct the lubricant 22 downwardly back to the interior portion 20. Since the first baffle 54 extends substantially orthogonally with respect to the body portion 34, for the lubricant 22 to move past the first baffle 54 it would have to make yet another turn of approximately 90 degrees.
Continuing to look at
The body portion 34 is preferably located in the assembly housing 10 before the elbow 32 is located in the body portion 34. The body portion 34, being comprised of a flexible, rubber-like material, can be pushed into the aperture 24. This is despite the fact that the lower seal 92 has a larger outer diameter 114 (
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiments. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
