Planetary gear transmission systems or components – Differential planetary gearing – Differential or nondifferential planetary combined with...
Patent
1991-04-22
1993-01-05
Braun, Leslie A.
Planetary gear transmission systems or components
Differential planetary gearing
Differential or nondifferential planetary combined with...
475231, F16H 138, F16H 144
Patent
active
051765896
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention concerns a differential gear having a differential gear housing driveable for rotation, the shafts of differential planet wheels being arranged in said housing for rotation therewith, the planet wheels being freely rotatable per se and having side wheels meshing therewith, said side wheels being freely rotatably journalled relative to the differential gear housing and being in rotational connection with a respective shaft rotatable relative to the differential gear housing.
BACKGROUND OF THE INVENTION
Such a differential gear is commonly used in motor vehicles to distribute the drive power from the drive engine to two driving wheels. The differential gear housing carries a crown wheel meshing with a differential drive pinion which in turn is driven by the motor. The side wheels are directly connected to a respective output shaft carrying a driving wheel. Known differential gears have the serious drawback that they function as intended only when the driving wheels are in full frictional engagement with the ground. As soon as a driving wheel looses its full engagement, the driving capacity of the other driving wheel is correspondingly decreased so as to entirely cease when the first driving wheel has lost all frictional contact with the ground. This peculiarity of conventional differential gears involves great risks in skid situations, particularly in connection with the so called secondary skid. A secondary skid occurs after a primary skid when both driving wheels, according to the above, have lost their driving capacity. During the primary skid the driving wheel leading in the direction of skidding has at least some engagement in the direction of traction, while the other driving wheel is more or less raised from the ground. The differential gear then transfers substantially all drive power to the easiest driveable driving wheel, i.e., the raised one, in which is built up a large mass energy.
When the primary skid ceases, this driving wheel regains its contact with the ground, whereupon the stored energy is instantaneously transferred to the ground, resulting in a violent thrown in the opposite direction. Unlike the primary skid, which is built up relatively slowly, the secondary skid occurs considerably faster and often has serious consequences.
It is apparent from the above presentation that there is a need to be able to control the power distribution to the output shafts of a differential gear. A known extremity in this respect is the differential lock that blocks the distributing function of the differential gear such that the output shafts are rigidly interconnected. The advantages and disadvantages of such lock herewith are well known. Further, so called anti-spin systems are known which lower the drive power until wheel spin ceases, but which cannot direct the drive power to a selective driving wheel.
SUMMARY OF THE INVENTION
The object of the present invention, thus, is to provide a differential gear which makes it possible to completely freely distribute input power between the two output shafts of the gear, i.e., to choose everything from a pure differential lock function to a function where the shafts rotate oppositely.
The differential gear of the present invention, thus, is basically a conventional differential gear which is completed with at least one planetary gear. More precisely, it is a differential gear, at least one output wheel (side wheel) of which carries the planet wheel holders of a planetary gear, the sun wheel of which is freely rotatably journalled relative to the shaft of the side wheel, and the ring wheel of which is rigidly connected to the differential gear housing.
In a first, preferred embodiment of the invention, the differential gear can be so arranged that the sun wheel is connected to a control shaft in the shape of a hollow shaft which is journalled on the shaft of the side wheel, which, in this case, is one output shaft of the gear. Control of the gear is accomplished in that the control shaft and therewith the sun
REFERENCES:
patent: 2884808 (1959-05-01), Mueller
patent: 3446092 (1969-05-01), Moan
patent: 3722300 (1973-03-01), Crooks
patent: 3722301 (1973-03-01), Crooks
patent: 3915033 (1975-10-01), Polak
patent: 4207780 (1980-06-01), Saxton
Braun Leslie A.
Macris Harold F.
LandOfFree
Differential gear does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Differential gear, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Differential gear will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2388307