Lubrication – Systems – Splash
Reexamination Certificate
1999-05-05
2001-06-12
Bucci, David A. (Department: 3682)
Lubrication
Systems
Splash
C384S472000
Reexamination Certificate
active
06244386
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a power transmission unit for motor vehicles, and more specifically to a lubrication apparatus for use in the power transmission unit which can provide good lubrication of bearings supporting an elongated rotary shaft within a casing of the power transmission unit even when the vehicle body is in an inclined state.
There is known as a related art a lubrication apparatus used in a final drive and differential unit for motor vehicles, of such a type that includes a casing elongated in a fore-and-aft direction of the motor vehicle and receiving lubricating fluid, a differential case arranged at a rear end of the casing, a differential gear unit rotatably disposed within the differential case, a drive gear mounted to the differential case, and a drive pinion shaft that is formed with a drive pinion meshing with the drive gear. The drive pinion shaft is elongated forward to be connected with a front-wheel side trans-axle via a propeller shaft. The drive pinion shaft is rotatably supported by a pair of axially spaced tapered roller bearings at a rear portion thereof near the differential case and by a ball bearing of a sealing type at a front portion thereof. The ball bearing of the sealing type is filled with grease. With this arrangement, when the motor vehicle is in a normal horizontal position, the roller bearings and the ball bearing are immersed in the lubricating fluid to be sufficiently lubricated. On the other hand, when the motor vehicle runs on a rapid ascent, the ball bearing lifts up from the level of the lubricating fluid whereby positive lubrication of the ball bearing is not achieved. This is the reason why the ball bearing of the sealing type is used at the front portion of the drive pinion shaft. Meanwhile, when the motor vehicle runs on a rapid descent, the roller bearings at the rear portion of the drive pinion shaft are still immersed in the lubricating fluid owing to a volumetric difference between a front end portion of the casing and a rear end portion thereof.
SUMMARY OF THE INVENTION
It will be noted that the related art requires three bearings by which the elongated drive pinion shaft is rotatably supported relative to the casing. This causes increase in weight and manufacturing cost of the motor vehicle. Further, it is required to use the expensive bearing of the sealing type described above, for providing lubrication of the bearing that lifts up from the level of the lubricating fluid within the casing in response to inclination of the vehicle body upon the motor vehicle running on a slope. The manufacturing cost thus will more increase due to the use of the expensive bearing of the sealing type.
It is an object of the present invention to provide a lubrication apparatus in a vehicular power transmission unit that is capable of providing good lubrication of a bearing supporting a shaft within a casing, even when the bearing lifts up from the level of lubricating fluid within the casing in response to inclination of the casing upon the motor vehicle running on a slope, and serving for reducing the manufacturing cost and the weight of the vehicle body.
According to one aspect of the present invention, there is provided a lubrication apparatus in a power transmission unit for a motor vehicle, comprising:
a shaft having an axis and being rotatable about the axis;
a casing receiving said shaft, said casing having opposed axial end portions spaced in a direction of the axis of said shaft;
a bearing supporting said shaft and disposed at one of the opposed axial end portions of said casing;
a lubricating fluid within said casing, said lubricating fluid having a level;
pickup means for picking up the lubricating fluid within said casing upon rotation of said shaft, said pickup means being disposed on said shaft and having a portion below the level of said lubricating fluid; and
guide means cooperating with said pickup means for supplying said bearing with the lubricating fluid, said guide means allowing the lubricating fluid picked up to flow by gravity to the one of the opposed axial end portions of said casing, said guide means being dispose on said casing.
According to a further aspect of the present invention, there is provided a lubrication apparatus in a power transmission unit for a motor vehicle, comprising:
a shaft having an axis and being rotatable about the axis;
a casing receiving said shaft, said casing having an axis and opposed axial end portions spaced in a direction of the axis of said shaft;
a bearing supporting said shaft, said bearing being disposed at one of the opposed axial end portions of said casing;
a lubricating fluid within said casing, said lubricating fluid having a level;
a pickup member picking up said lubricating fluid within said casing upon rotation of said shaft, said pickup member being disposed on said shaft and having a portion below the level of said lubricating fluid; and
a trough allowing said lubricating fluid picked up to flow by gravity to the one of the opposed axial end portions of said casing, said trough being disposed on said casing and extending between the opposed axial end portions of said casing.
According to a still further aspect of the present invention, there is provided a method of lubricating a bearing supporting a shaft within a power transmission casing of a motor vehicle, said shaft having an axis and being rotatable about the axis, said power transmission casing having opposed axial end portions spaced in the axial direction of the shaft and containing lubricating fluid, said bearing being disposed at one of the opposed axial end portions of the casing, the method comprising:
picking up the lubricating fluid within the casing upon rotation of the shaft; and
guiding the lubricating fluid picked up, by gravity, to the one of the opposed axial end portions of the casing.
REFERENCES:
patent: 1631217 (1927-06-01), Matthews
patent: 1771835 (1930-07-01), Bartlett
patent: 1787428 (1931-01-01), Fekete et al.
patent: 2191326 (1940-02-01), Smith et al.
patent: 2195877 (1940-04-01), Steedman
patent: 2583317 (1952-01-01), Belich
patent: 3383937 (1968-05-01), Toenne et al.
patent: 3763961 (1973-10-01), Casale
patent: 3857462 (1974-12-01), Kaufman et al.
patent: 4217794 (1980-08-01), Yasui et al.
patent: 4242923 (1981-01-01), Nishikawa et al.
patent: 4348914 (1982-09-01), Kawamoto
patent: 4612818 (1986-09-01), Hori et al.
patent: 4677871 (1987-07-01), Taniyama et al.
patent: 5232292 (1993-08-01), Kuan
patent: 5316106 (1994-05-01), Baedke et al.
patent: 5328275 (1994-07-01), Winn et al.
patent: 5499902 (1996-03-01), Rockwood
patent: 5513964 (1996-05-01), Rockwood
patent: 5591020 (1997-01-01), Rockwood
patent: 5647735 (1997-07-01), Rockwood
patent: 5699877 (1997-12-01), Dreier
patent: 6109393 (2000-08-01), Toyota et al.
patent: 825 359 (1951-11-01), None
patent: 19 79 972 (1968-02-01), None
patent: 2142 249 (1973-03-01), None
patent: 27 33 294 A1 (1978-02-01), None
patent: 41 15 381 A1 (1991-11-01), None
patent: 40 23 354 A1 (1992-01-01), None
patent: 0 167 388 (1986-01-01), None
German periodical, Maschinenmarkt, Wurzburg 86, 1980, pp. 1043 to 1046.
Patent Abstracts of Japan of Published Publication 2-62462(A) (Sobotani).
Patent Abstracts of Japan of Published Publication 3-288055(A) (Yamashita).
Kusukawa Hirotaka
Takasaki Toshiharu
Bucci David A.
Foley & Lardner
Kim Chong H.
Nissan Motor Co,. Ltd.
LandOfFree
Lubrication apparatus in power transmission unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lubrication apparatus in power transmission unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lubrication apparatus in power transmission unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2482830