FIELD OF THE INVENTION

Differential gear drives are used frequently in motor vehicles, in order to compensate for different rates of rotation of driven wheels. In the case of lockable differentials, two kinds are generally differentiated between. One is a lockable differential, which is put into the locked state by an external activation apparatus, in which, by the activation of the said external activation apparatus, the differential action of the differential can be partially or fully withheld. The other is the self-acting, locking differential. In the case of the self acting differential, the locking action is based on interior friction, which opposes the differential motion. Usually, for both kinds of the differential, lamellar clutches are employed for the suspension of the differential activity.

BACKGROUND OF THE INVENTION

DE 195 47 980 A1 discloses a differential gear drive, which develops, by means of the varied speed of rotation of the driven wheels, a braking torque. This said torque partially suspends the differential action of the differential drive. In this case, the differential cage comprises two parts, which are connected by means of bolts. A bevel gear, which is driven by a drive pinion, is connected to the differential cage by an additional bolt fastening.

DE 38 39 787 C2 makes known a differential drive, in which case the differential effect of the said drive can be suspended by means of an external activation of an activation apparatus. The differential cage of the differential drive consists of two parts, wherein one part of the differential cage is driven. The fastening of the drive gear is not shown.

The purpose of the present invention is to create a differential drive, wherein the drive pinion and the driven bevel gear, which is connected to the differential cage, as well as a principal component of the differential cage and the therein employed differential bevel gears, can serve as,an external lockable differential drive as well as a self-acting lockable differential drive.

SUMMARY OF THE INVENTION

In accordance with the invention, the driven bevel gear, which is connected with the differential cage, is so designed, that it possesses two, oppositely disposed contact faces. Of these two, the first contact face serves as seat for the clutch lamina which serve for the locking of the differential motion by externally activated locking means. The second contact face, which lies opposite the first contact face, serves as a seat for a clutch in a self-locking differential drive. The differential cage possesses on the one hand, an opening, through which the installation of the differential gears is made and which also possesses a space in which the clutches, in the case of a self-locking differential drive can be installed and on the other hand, possesses a first contact face for the bearing of the differential cage in the axle housing. The drive side differential bevel gears, which are to be found in the differential cage, possess fastening points for the securing of the inner laminae of the clutches for locking the differential drive. The driven bevel gear is so fastened as to turn in common with the differential cage and partially closes the opening of the differential cage, whereby, the second contact face, which serves as a seat for the clutch of the self-locking differential drive, can extend itself into the said differential cage. The driven bevel gear, which, as said, is rotatably affixed to the differential cage, is located between the differential cage and a cover, which cover is affixed by fastening elements with both the driven bevel gear and the differential cage, and possesses moreover a second location for the setting of the differential drive in bearings in the axle housing. While the driven bevel gear is placed between the cover and the differential cage, it becomes possible, in accord with the individual circumstances, to permit the clutches to seat upon the said contact faces of the bevel gear. Different covers are used, if the lockable differential drive is to function as a self-locking drive or be activated by an external activation apparatus. By means of this arrangement, it is possible, in the case of a self-locking differential drive and also in the case of an externally activated locking differential drive, to make the principal components of the differential cage, the differential bevel gears in the differential cage, and the driven bevel gear, without any changes. If a split axle housing is employed, which, can, possibly, encapsulate the differential drive, then, additionally, this part, which extends over the differential drive, can also, for both kinds of differential drives, be made and shaped the same. By this means, it is possible to create an assembly method, in which both kinds of differential drives, with many identical components can be manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 a locking differential drive, which can be locked by external activation of an activation apparatus, and

FIG. 2 a locking differential drive, which, reduces the differential effect in a self-acting manner by means of variation in the speed of rotation of the driven wheels.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1:

A drive pinion 1 drives a crown wheel 2, which is affixed to rotate with the differential cage 3. The crown wheel 32 is placed between a differential cage 3 and a cover 4. By means of an external, pressure connected, activation means 5, upon application of pressure thereon, an axial force is exerted on the clutch 6, which said clutch seats itself against a first contact face 7 of the crown wheel 2. The crown wheel 2 possesses a second contact face 8, with which the crown wheel 2 lies against the differential cage 3. The differential cage 3 possesses, one opening 9, through which the differential bevel gears 10 may be inserted.

The output side differential bevel gears 11 possess, respectively, a structural member 12, which serves for the reception of the lamina of the clutch 6. The differential cage 3 is, first, carried in bearings by a bearing set 13 and, second, by a bearing set 14, both being located in the axle housing 15. The cover 4, the crown wheel 2, and the differential cage 3 are so fastened by securing means as to turn with each other.

FIG. 2:

A drive pinion 1 drives a crown wheel 2, which is connected to a differential cage 3. The crown wheel 2 possesses two contact faces, a first contact face 7 and a second contact face 8, whereby the second contact face 8 serves as a seat for the clutch 17 and also as a seat for the crown wheel 2 on the differential cage 3. The differential gears 11, which can be mounted with the differential bevel gears 10 through an opening 9 in the differential cage 3, possess a structural element 12, on which the clutch 17 is placed. The differential cage 3 possesses, first, a bearing 13, and is, second, turnably secured by a fastening means 16 to a cover 4 and the crown wheel 2, whereby the cover 4 possesses a bearing set 14. By means of the bearing sets 13 and 14, the differential drive is carried on bearings in the axle housing 15. Inasmuch as the crown wheel 2, in its radial extent, is less than the radial extent of the opening 9 of the differential cage 3, it is possible to make use of the crown wheel 2 as a contact face for the clutch 17. By means of the difference of the differential bevel gears 11, a friction in the clutches 17 is produced, which minimizes the differential effect of the differential drive.

Reference Numbers and Items

1 Drive pinion

2 Crown wheel, also known as ring gear

3 Differential cage,

4 Cover

5 Activation apparatus

6 Clutch

7 First contact face

8 Second contact face

9 Opening in differential cage

10 Differential bevel gear

11 Differential bevel gear

12 Structural element

13 Bearing

14 Bearing

15 Axle housing

16 Fastening means

17 Clutch