A differential gearbox including a disk on the input side, a first drive part that is non-rotatably connected to a first driven axle, and a second drive part that is non-rotatably connected to a second driven axle. A planetary gear arrangement is provided between the first drive part and the second drive part for transmitting torque from the disk on the input side to the first drive part and the second drive part. The first drive part is a first drive disk and includes a concavity radially outwardly of the first driven axle. The second drive part is a second drive disk extending radially outwardly of the second driven axle. The concavity is directed away from the second drive disk. The planetary gear arrangement is disposed in a space that is formed by the concavity of the first drive disk and the opposing region of the second drive disk.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a transmission arrangement, particularly a differential transmission.

2. Description of the Related Art

DE 10 2007 033 700 A1 discloses a continuously variable conical pulley transmission that includes an input-side and an output-side conical pulley set. Every conical pulley set features a fixed disk and a movable disk that is arranged, respectively, on an input-side and an output-side shaft, and are connectable over a continuously variable means for torque transmission.

DE 196 31 243 C2 discloses a transmission unit for a motor vehicle, among others, in which the fixed disk of a continuously variable transmission (CVT) is in connection with a differential via a driving axle and a planetary transmission that in the drive train is followed by a drive axle, and hence the drive wheel connected with it. A problem with such transmission arrangements is that they require a relatively large assembly space and are relatively heavy.

An object of the present invention is to provide a transmission arrangement to connect a differential to a disk set of a continuously variable transmission, whereby the transmission arrangement should be comparatively compact, weight convenient, and economically producible.

The object is achieved by a transmission arrangement with the features hereinafter described.

SUMMARY OF THE INVENTION

The essential advantage of the transmission arrangement in accordance with the present invention exists in that the planet gears of an axle differential are displaced radially outwards, so that they can lie axially near the fixed disk of a continuously variable transmission. In this manner, an extremely compact, radially space-saving transmission arrangement is provided, and the thickness of the planet gears can be reduced. In this manner, the entire transmission arrangement is relatively economical and producible in an assembly-space-neutral manner, and is comparatively light in weight because the axle differential is essentially producible of simple sheet metal parts.

The differential in the transmission arrangement in accordance with the present invention can be mounted advantageously, as a pre-assembled compact component, directly on a disk set of a continuously variable transmission.

Because the driven axles of the differential of the transmission arrangement in accordance with the present invention feature the form of hollow shafts connected directly with the wheels of a motor vehicle, or directly with the individual axle differentials of an all-wheel-drive vehicle that are supported coaxially to each other, further saving of assembly space would prove advantageously attainable.

The present transmission arrangement is particularly advantageously suitable for use with a continuously variable transmission in a front-transverse arrangement or for assembly-space-critical installations.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance withFIG. 1, the present transmission arrangement includes essentially a fixed disk2, of a disk set of a continuously variable transmission1(CVT) on a first driven axle20relating for example to a front axle of a vehicle, disposed rotatably through a bearing22, whereby the movable disk of the disk set is not shown. The first driven axle20is arranged coaxially to a second driven axle21in the manner clarified in detail later, for example, where it relates to the other front axle of the vehicle.

The fixed disk2arranged rotatably on the first driven axle20through the bearing22features a formed, driving axle part3that is rotatably supported and fixed with the help of a bearing17, which preferably relates to a ball bearing in the housing15of the present transmission arrangement.

The driving axle part3of the fixed disk2is in connection non-rotatably, via a tooth system4, with a disk part5, which preferably is provided as a sheet metal part. Thereby, a part4′ of the tooth system4is arranged on the interior circumference of the driving axle part3, while the other part4″ of the tooth system4is arranged on the outside circumference of an attachment region26of disk part5extending preferably axially to the side of the fixed disk2. The disk part5extends essentially radially outwards, whereby it extends preferably with a first concavity27extending away from the fixed disk2, starting from the axial attachment region26, around the bearing17, and around the bearing region45of the housing15holding bearing17. Radially outside the bearing region45the disk part5includes a second concavity28that extends toward the fixed disk2, preferably in an area29, axially in the direction toward the fixed disk2, in order to extend with an area30radially outwards. On the radially outside, free end region of the disk part5, an axially extending carrier part6is arranged for the-planet gears11and12of the differential. The carrier part6is welded preferably with the disk part5as indicated by the weld seam7.

On the first driven axle20, a first drive disk18is arranged, which is connected non-rotatably with the driven axle20via a tooth system25. Thereby, a part25′ of the tooth system25is preferably arranged inside an attachment region31of the first drive disk18, extending axially to the side of the fixed disk2, while the other part25of the tooth system25is arranged outside on an axial region32of the first driven axle20.

On the second driven axle21, a second drive disk16is arranged, which is connected non-rotatably with the second driven axle21via a tooth system37. Thereby, a part37′ of the tooth system37is arranged inside on an attachment region55of the second drive disk16, preferably to the side of the fixed disk2and extending axially, while the other part37″ of the tooth system37is arranged outside on an axial region38of the second driven axle21.

The first drive disk18is adapted to the form of the disk part5, i.e., it features a second concavity33that extends around the first concavity27of the disk part5on the side facing away from the fixed disk2, a region51extending axially rearward in the direction toward the disk part5, and subsequently a third concavity34arranged in the region of the concavity28of the driven disk34, which engages into the second concavity28of the disk part5. The free end region35of the first drive disk18lying radially outside is turned through 90° relative to the radially extending region of third concavity34so that it extends radially inside and parallel to the carrier part6. Through this arrangement of the disk part5and the first drive disk18the result is that the disk part5and the first drive disk18lie closely next to one another in the axial direction, and in the radial direction they can be nested in each other. Altogether, they therefore require an extremely small assembly space in the axial direction.

Preferably, both the first drive disk18and the second drive disk16are in the form of sheet metal parts.

On a web part39, extending radially inwardly at the middle of the axially-extending carrier part6between the ends of the end regions35and36facing one another, an axial shaft19is provided for carrying the planet gears11and12. Thus, more precisely, on the shaft19as shown inFIG. 3, with the help of a first bearing41, the first planet gear12is supported rotatably on the side facing the fixed disk2, and is in connection with the free end region35of the first drive part18via a tooth system14. A part14′ of the tooth system14is formed by the teeth of the planet gear12while the other part14″ of the tooth system14is arranged inside on the free end region35of the first drive disk18. In a corresponding manner, the second planet gear11is supported rotatably on the shaft19on the side facing the second drive disk16, as shown inFIG. 3, with the help of a second bearing43. Planet gear11is in connection with the end region36of the second drive part16via a tooth system13. A part13′ of the tooth system13is formed by the teeth of the planet gear11while the other part13″ of the tooth system13is arranged inside on the end region36of the second drive disk16.

The first planet gear12is supported on a bearing9held on the first drive disk18on its side facing the first driven disk18which preferably involves a needle bearing. In a corresponding manner, the second planet gear11is supported on its side facing the second drive disk16on a bearing10held on the second drive disk16, which preferably likewise involves a needle bearing.

The drive disks16,18are fixed in the axial direction on the driven axle parts20and21, in that its attachment areas37and/or31are supported on shoulder areas53and/or54, which are arranged on the driven axle parts20,21.

In the following, the function of the transmission arrangement described above in detail is clarified.

In a straight-line motion, the planet gears11,12do not rotate relatively to one another because the driven axles20and21rotate at the same speed. The two driven axles21and20are driven uniformly from the fixed disk2over the driving axle part3, the tooth system4, the disk part5, the axially-extending carrier part6, the tooth systems13and14, as well as the drive disks16and18. Thereby, the stationary planet gears11,12are carried along and they transmit drive torque via the meshing teeth of the tooth systems13and14.

When driving along a curve, the driven axles20and21rotate at different rotational speeds, whereby the drive disks16and18likewise rotate at different rotational speeds. The planetary gears11,12therefore rotate on the shaft19at different rotational speeds in order to compensate for that difference in rotational speeds of the drive disks.

The coaxial connection of the driven axles20,21occurs preferably through a hollow shaft construction, either directly to the driven wheels, or to the individual axle differentials for all-wheel drive vehicles. In accordance withFIG. 1, a second driven axle21includes an axial extension46that engages in an axial bore47of first driven axle20, whereby a bearing42is arranged between the surfaces of the axial extension46and the axial bore47that face one another. As shown inFIG. 2, both the first driven axle20and the second driven axle21include an axial bore49and50, respectively, whereby in the end regions of the bores49,50that face one another, a rotational insert52for providing oil engages the axles in a bridging and centering manner.

At the side of the disk part5facing the fixed disk2, attachment elements44can be provided, which are distributed around the circumference of the disk part5and form a sensor wheel, or serve for a parking pawl linkage.