GB2319008A

GB2319008A - Drive arrangement for all-wheel drive vehicles with at least three axles

Info

Publication number: GB2319008A
Application number: GB9723480A
Authority: GB
Inventors: Roland Dold
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1996-11-07
Filing date: 1997-11-06
Publication date: 1998-05-13
Anticipated expiration: 2017-11-06
Also published as: GB9723480D0; NL1007460C2; GB2319008B; ZA9710004B; FR2755408A1; NL1007460A1; FR2755408B1; DE19645898C1

Abstract

A drive arrangement for an all-wheel drive vehicle with at least three axles 2,3,4 has a transmission outputting to an interaxle transfer gear 23 which lies between the axle gears 6,7 which comprise differential gears with a ring gear 17 which meshes with a bevel gear 18 on the input shaft 9. An intermediate gear comprising a gear wheel 19 on the input shaft 9 and a gear wheel 20 which is situated to the side of and vertically offset with respect to the shaft 9 is connected to shaft 21, to allow the shaft 21 connected to the following axle 4 to run beneath the drive shafts 12,13 connected to the wheels 5.

Description

1 2319008 Drive arrangement for all-wheel drive vehicles with at least

three axles The invention relates to a drive arrangement for all-wheel drive vehicles with at least three axles which have axle gears.

Drive arrangements of the abovementioned type are known from corresponding studies in particular for military off-road vehicles, such as for example armoured cars or the like with three or four pairs of wheels. One of the main problems when designing vehicles of this kind is that they are intended to satisfy very diverse requirements, some of which are almost contradictory, and that nevertheless the financial outlay on such vehicles is to be kept low. With regard to the latter point, the possibilities for influencing this are limited in particular for the safety and weapons systems, so that the pressure to save money on the drive system is particularly great, which ultimately leads to the use, as far as possible, of units which are taken from large-scale series production, for example for commercial vehicles, or are at least derived from such production, despite the special requirements placed on these vehicles.

Accordingly, for the known drive arrangement put forward in the first paragraph an underbody is used in which an axle gear which is based on seriesproduction solutions is used for each of the three driveable axles of the vehicle, and in each case a two-wheel intermediate spur gear is associated with this axle gear, the arrangement being such that for all three axles the drive is effected jointly via a shaft train, to which in each case the input wheel of the intermediate spur gear is coaxially connected and to which the enginegearbox unit is connected via an interaxle differential which is arranged in the shaft train between the first and second axles. In principle, although this arrangement is advantageous and also expedient, it does make it difficult to achieve vehicles with a low silhouette while maintaining the necessary high ground clearance, particularly if these vehicles are to be used as armoured cars, weapon carriers, troop-carrying vehicles or else as armoured field ambulances while retaining essentially the same basic design of the drive arrangement.

This results inter alia from the fact that the shaft train connecting the axles runs in a laterally offset manner with respect to the longitudinal centre of the 2 vehicle over practically the entire length of the vehicle interior and, for the axle gears of all the axles, requires a vertical position which allows even the interaxle differential to be accommodated inside the floor pan, although the floor pan usually has its deepest point at the centre and runs upwards towards the sides.

In this respect, greater freedom is granted by drive arrangements in accordance with German Patent 3637523 (DE 3637523C1), since in this case the axle gears of the four-axle vehicle are driven in pairs via in each case one shaft train and the shaft trains lie on different sides of the centre of the vehicle. This is achieved by means of a configuration of the axle gears in which the latter can be employed rotated about 180 with respect to a vertical axis and, moreover, are in each case designed in such a manner that, with the drive shaft train for the respective gear lying on one side of the vehicle longitudinal centre, this gear leaves sufficient free space on the side facing the longitudinal centre, for the second shaft train to pass through.

The present invention seeks to provide a finther drive arrangement which is distinguished by particularly good conditions with regard to variable vehicle designs.

According to the present invention, there is provided a drive arrangement for all-wheel drive vehicles with at least three axles which have axle drives arranged in the longitudinal centre area of the vehicle, a transmission arranged adjacent the engine and outputting to an interaxle transfer gear, which lies between axle gears of two adjacent axles, and driving the axle gears, which comprise differential gears with wheel drive shafts which lead to the wheels, via in each case one bevel gear which meshes with the ring gear of the differential gear, an intermediate gear, which has a first gear wheel which is coaxial with the bevel gear and a second gear wheel which is situated to the side of and vertically offset with respect to the bevel gear, is mounted at least partially in front of the differential gears of the axles, wherein the interaxle transfer gear is connected in drive terms coaxially to the bevel gears of the axle gears of the two adjacent axles, and the drive for axles which follow the adjacent axles passes via the intermediate gear of the said following axles and via the intermediate gear of the respectively closer one of the adjacent axles, and the shaft axle connecting the second gear wheels thereof running beneath the drive shafts which run from the differential gears to the wheels.

The starting point for this is a drive arrangement with conventional axle 3 gears, in which the cage of the differential gear is connected to a ring gear, and this ring gear is driven via a bevel gear which is at an angle thereto. Although a solution of this Idnd is preferably used, since it is generally customary in series production, in principle it is also possible within the scope of the invention to use other differential gear designs, as long as they allow a suitable input into the axle. Arranging the axle gears in the longitudinal centre, with a corresponding position of the bevel gears, preferably in or close to the plane of the longitudinal centre, in conjunction with a corresponding arrangement of the interaxle transfer gear between two adjacent axles, enables the interaxle transfer gear to be accommodated in the central, particularly deep floor region, thus enabling the space to be used particularly well, in turn allowing the engine-gearbox unit to be accommodated in essentially the same region of the vehicle even with a low vehicle silhouette, this arrangement of the engine-gearbox unit being, for example, laterally offset sufficiently far for the driver of the vehicle still to be able to sit on the other side, despite the low silhouette.

Since the drive shaft train is interrupted and the axle(s) which follow(s) the two adjacent axles connected by the interaxle transfer gear islare driven via a separate shaft train, it is possible to position this shaft train almost independently of the spatial restrictions caused by an interaxle transfer gear, so that this shaft train, owing to its low spatial requirement, can run offset downwards and to the side of the shaft train which includes the interaxle transfer gear. It is preferably offset sufficiently far downwards for the laterally offset shaft train to run beneath the output shafts, which start from the differential gear, for the wheel drives.

Irrespective of the intermediate gears used, axle gears which are of fundamentally identical construction can be used for all axles, in which case, of the two adjacent axle gears, which are connected by the interaxle transfer gear, of the preferably front axles of the vehicle, the gear assigned to the very front, i.e. first, axle of the vehicle is rotated through 180' about a vertical axis with respect to the axle gear of the second axle, so that the side wheel of the intermediate gear can be used to drive a connecting shaft or the like for additional equipment, winches or similar devices. The arrangement and selection according to the invention of the axle gears thus allows a free output for the connection of any desired equipment on the front and the rear without additional expenditure.

4 The mutually adjacent axles which are connected by the interaxle transfer gear are preferably assigned an interaxle differential which is integrated in the interaxle transfer gear. Corresponding provisions can also be made for the axle or axles driven via the laterally offset shaft train, a corresponding interaxle differential, preferably in lockable form, preferably being assigned to that gear wheel of the intermediate gear which is coaxial with the bevel gear of the differential gear and via which the laterally offset shaft train is driven.

The basic construction according to the invention, outlined above, makes it possible to use axle gears which are of at least largely identical construction on all the axles. According to the invention, the direct and indirect input flanges which are usually present in such axle gears may be employed alternately in a particularly advantageous manner and thus permit the desired variability without additional expenditure and with favourable component logistics.

An additional alternative in this respect is opened up within the scope of the invention by the fact that a split design is selected for the axle(s) driven by the lateral shaft train. This is to be understood as meaning that the respective axle gear is arranged in a longitudinally offset manner, as it were out of the position between the wheels, preferably offset as far as possible towards the front, i.e. adjacent to the axle gear of the second axle, and that the longitudinal offset between the axle gear and the wheel output is bridged by side shaft trains which are offset far towards the sides of the vehicle. A so-called H drive train of this kind, which can also be realized for the wheels of two axles situated one behind the other, starting from an axially offset axle gear, by suitably lengthening the shaft trains situated at the sides, results in particularly great spatial advantages in the corresponding region of the vehicle.

The invention is explained in more detail below with reference to exemplary embodiments. In the drawing:

Figure 1 shows a diagrammatic plan view of the drive train of an allwheel drive, three-axle vehicle, neither the engine-gearbox unit provided for the drive nor the further structure of the vehicle being illustrated, Figure 2 shows a diagrammatic illustration of an engine-gearbox unit in side view, such as that which can be used in conjunction with a drive train in accordance with Figure 1, Figure 3 shows an illustration, corresponding to Figure 1, of a drive train of an all-wheel drive, four-axle vehicle, Figure 4 shows an illustration, corresponding to Figure 1, with an additional interaxle differential in the drive train, Figure 5 shows an illustration, corresponding to Figure 3, with an additional interaxle differential in the drive train, Figure 6 shows a more simplified sectional illustration through the second axle in accordance with Figure 1, sectioned on line VINI, Figure 7 shows a diagrammatic illustration of an interaxle transfer gear, as can be used as an input between the first and the second axle in the illustration in accordance with Figure 1, Figure 8 shows a further, diagrammatic outline illustration of the drive train of a three-axle, all- wheel drive vehicle, for which, as in the previous illustrations, neither the engine-gearbox unit nor the structure and the other components of the vehicle are shown, Figure 9 shows a drive train whose fundamental structure corresponds to Figure 8, illustrated in accordance with Figure 8, for an all-wheel drive, fouraxle vehicle, and Figures 10 to 15 show diagrammatic outline illustrations of three-axle, all-wheel drive, armoured military vehicles based on drive trains which are constructed in accordance with the invention, the engine-gearbox unit, and also some useable spaces of the vehicle, being outlined, all this in combination with various configurations of an armoured body.

In the illustration in accordance with Figure 1, which essentially only shows the diagram of a drive train for all-wheel drive, off-road vehicles, the three driven axles of the threeaxle vehicle, which is denoted overall by 1 and is not illustrated in further detail, are denoted by 2-4, each of the axles 2-4 being provided with two wheels 5 and, centrally between their wheels 5, having an axle gear 6, 7 and 8, in plan view approximately on the longitudinal centre axis of the vehicle. The axle gears 6, 7 and 8 are of essentially identical design, the axle gears 7 and 8 being arranged identically while the axle gear 6 is installed in a position in which is has been rotated through 180 about a vertical axis with respect to the axle 6 gears 7 and 8.

The identically designed axle gears 6-8 each have an input shaft 9 and are designed as differential gears which allow different rotational speeds for the lateral output shafts 10 and 11 which lead to the wheels lying on both sides of the axle gears 6-8. As indicated further, the output shafts 10 and 11 are connected in an articulated manner to wheel shafts 12 and 13, which in turn are connected in an articulated manner to the wheel-side shaft journals 14 and 15 of the independently attached wheels; the guides for the wheels are not illustrated in more detail here and may be of known design.

The output shafts 10 and 11 are connected in a conventional manner to the corresponding differential pinions of the differential gear, which is not described in more detail here, is of conventional design and the cage 16 of which is connected to a ring gear 17 coaxially and in a rotationally fixed manner, which ring gear for its part meshes with a bevel gear 18 arranged on the input shaft 9.

Mounted before the bevel gear 18, on the input side of the respective axle gear 6, 7, 8, is an intermediate gear which, as illustrated for the axle 3, comprises a gear wheel 19 arranged on the input shaft 9 and a gear wheel 20 which meshes with the gear wheel 19 and is connected in a rotationally fixed manner to the shaft 21, which is mounted in the gear parallel to the input shaft 9, but offset laterally and vertically.

While in the exemplary embodiment the axle gear 6 associated with the front axle, based on the direction of travel F, in this case the axle 2, is not lockable, the axle gears 7 and 8 of the axles 3 and 4, whilst otherwise being of identical design, are lockable, as illustrated symbolically at 22. These switchable locks 22, depending on the switching state, can be used to connect the wheels 5 of the respective axle to one another in a rotationally fixed manner. However, it also falls within the scope of the invention for the axle 2 to be of lockable design.

The two front (based on the direction of travel F), mutually adjacent axles 2 and 3 are, with regard to their input shafts 9, connected coaxially to one another in drive terms, the input being effected via a differential transfer gear 23, which is preferably designed as a lockable transfer gear, for example in accordance with the illustration shown in Figure 7. The input shafts 9 of the axle gears 6 and 7 of 7 the two adjacent, front axles 2 and 3 are in this case connected via intermediate shafts 24 and 25 to the output shafts 26 and 27 of the interaxle transfer gear 23, the corresponding flange couplings being illustrated here only symbolically, as are the directions of rotation of the respective shaft trains, by means of corresponding arrows.

The coaxial drive for the two axle gears 6 and 7 of the two axles 2 and 3, in conjunction with the design of the axles, which is essentially symmetrical with respect to the longitudinal centre plane, and the coiTesponding position of the interaxle transfer gear 23, results in a solution in which the engine-gearbox unit in accordance with Figure 2, which is denoted overall by 28, can be combined with the drive train in a space-saving and procedurally favourable manner. Ile engine-gearbox unit 28 comprises an engine 29 and the gearbox unit 30. They are longitudinally offset with respect to one another, and the gearbox unit 30 comprises, in addition to a manual or automatic gearbox 30a, which is not illustrated in detail, a series of power take-offs 30b, which are likewise not illustrated in detail and are driven by the interposition of an additional gearbox 30c and, in the exemplary embodiment, are formed by pumps, in particular hydraulic pumps. The structure outlined above and explained schematically, of the engine-gearbox unit 28 also has the face and reversing pinions which can be seen in the drawing, with the corresponding shaft couplings, which are selected in such a manner that there is a certain possibility for varying the arrangement of engine 29 with respect to gearbox units 28, thus enabling the engine-gearbox unit 28, with respect to Figure 1, to be positioned essentially on the right- hand side of the vehicle, between the axles 2 and 3, so that the left- hand corresponding area of the vehicle remains free for other purposes, in particular for the driver's seat. The position of the engine 29 with respect to the gearbox unit 30 is such that a bridging shaft 30d spans the gearbox 30a and the input to the gearbox 30a is effected on the side facing away from the engine 29, the input between the gearbox 30a and the additional gearbox 30c which follows the gearbox 30a on the side facing away from the engine 29 is effected via an intermediate gear 30e. This arrangement means that the interaxle transfer gear 23, with regard to the longitudinal extent of the vehicle, is accommodated between engine 29 and gearbox 30a, which is advantageous with regard to the spatial conditions and the weight distribution. However, the open grouping indicated if 8 necessary also allows other arrangements without making any major changes.

A design of the drive train in accordance with Figure 1 with the interaxle transfer gear 23 arranged in the longitudinal centre plane of the vehicle is particularly advantageous for body versions which have their deepest region for the floor area, in cross-section of the vehicle, in the longitudinal centre and have floor surfaces which run obliquely upwards on both sides from the longitudinal centre. This is because the gears 6 and 7 can then also be in a very low position in the vehicle, despite the interaxle transfer gear 23, without undesirably restricting the ground clearance of the vehicle.

The shaft train which produces the drive connection to the rear (based on the direction of travel), third axle essentially comprises the intermediate shaft 31, which connects the shaft 21 of the axle gear 7 of the axle 3 to the corresponding shaft 32 of the axle gear 8 of the axle 4. In contrast to the shaft 21, for this purpose the shaft 32 is led out of the gear casing on both sides, i.e. is provided with connections on both sides, but otherwise the axle gear 8 of the axle 4 corresponds to the axle gear 7 of the axle 3. There are thus no significant structural differences between the axle gears used, and the design of these gears is also conventional, so that standard products can be employed.

Owing to the small amount of space required by the shaft train comprising the intermediate shaft 31, this shaft train can be placed at a very low position, and in the exemplary embodiment is positioned with respect to the shafts 21 and 32 in such a manner that the latter are able to run beneath the output shafts 11 of the gears 7 and 8. This allows the space to be used optimally. This is illustrated in particular by Figure 6, which shows a diagrammatic cross-section of the axle 3, from which it can be seen that the use of the intermediate gear with the spur gear 19, which is coaxial with the bevel gear 18, and the gear wheel 20, which meshes with the said spur gear 19 and lies on the shaft 21, allows the desired vertical offset to be achieved in a simple manner. Naturally, it is possible, if required, to allow the shaft train with the intermediate shaft 31 also to run on the other longitudinal side of the vehicle, as an alternative to the exemplary embodiment illustrated. Figure 6 finthermore illustrates that wheel-hub gears 33 can advantageously be employed in conjunction with the invention, in order to achieve an overall drive-train structure which is as light as 9 possible and, as a result, further to improve the conditions for a space-saving design.

Figure 7 shows a diagrammatic depiction of the interaxle transfer gear 23, in order to explain how the latter functions, the interaxle transfer gear 23 here being illustrated as a planetary gear design with a differential function. As in Figure 2, the input is effected from the gearbox unit, which is denoted symbolically by 30, via an intermediate gear 34, which meshes with the planet-wheel carrier 35, which lies centrically with respect to the shaft of the sun gear 36, which is connected in drive terms to the internal-geared wheel 38 via the planet gears 37. The internal-geared wheel 38 and the sun gear 36 are connected to the output shafts 26 and 27 in accordance with Figure 1, the output from the shaft 26 leading, via the intermediate shaft 24, to the front axle, the axle 2, and the output from the shaft 27 leading, via the intermediate shaft 25, to the axle gear 7 of the second axle 3 of the vehicle. The locking fimction of the differential gear formed by the planetary gear is indicated symbolically and the shafts 26 and 27 are connected to one another in a rotationally fixed manner, if the planet- wheel carrier 25 is rotationally fixed with respect to the shaft 26.

The exemplary embodiment in accordance with Figure 3 shows the drive train of a four-axle, all-wheel drive vehicle, which is denoted overall by 101 and the basic structure of which, apart from the number of axles, corresponds to that in accordance with Figure 1. Corresponding reference numerals are therefore used for corresponding parts, but increased for differentiation purposes by the number 100 in each case.

The two front axles 102 and 103, in the direction of travel, are again driven by an interaxle transfer gear 123, and the input into the axles 102 and 103 is in each case coaxially central for the two axle gears 106 and 107 of these axles. Starting from the second axle 103, based on the direction of travel, the drive for the following axles 104a, 104b is again effected via a laterally offset shaft train, the corresponding intermediate shafts of which are denoted by 13 1 a and 13 lb. Via the intermediate shafts, the input to the axle gears 108a and 108b is effected via the respective intermediate gears, which are designed analogously to the intermediate gear formed by the gear wheels 119, 120 of the axle gear 107, and are correspondingly provided with the same reference numerals. In functional terms, and also with regard to the advantages which can be achieved, the embodiment in accordance with Figure 3 corresponds to that in accordance with Figure 1, so that in this respect reference is made to the corresponding description.

While the interaxle transfer gear 23 or 123, respectively, provides an interaxle differential function, in the embodiments in accordance with Figures 1 and 3, for the two front axles, there is no such function with regard to the ftu-ther axles of the vehicle, i.e. from the second vehicle axle to the third or to the third and fourth, respectively. For the second and third or for the second, third and fourth axles, respectively, in each case based on the direction of travel F, there are only provided locks 22 and 122, respectively, which act between the wheels associated with an axle.

Figures 4 and 5 now show exemplary embodiments in which differential gears are also provided in the drive connection, these differential gears branching off from the drive for the second axle and leading to the third axle or to the third and fourth axles, respectively, of the vehicle. Since the design in accordance with Figure 4 otherwise corresponds to the configuration in accordance with Figure 1 and the design in accordance with Figure 5 otherwise corresponds to the configuration in accordance with Figure 3, in the following description reference is only made to this modification, and otherwise the preceding parts of the description should be referred to. In order to simplify matters, corresponding reference numerals are again used, but this time, with regard to Figure 4 the reference numerals are 201 etc., and with regard to Figure 5 the reference numerals are 301 etc.

In the vehicle 201 in accordance with Figure 4, an interaxle differential gear 240, which is preferably integrated in the axle gear 207 and is arranged in front of the bevel gear 218, concentrically with its shaft 209, is provided in the transition from the interaxle transfer gear 223 between the axles 202 and 203 to the axle gear 207. The interaxle differential gear 240 comprises a cage 241, which is connected in a rotationally fixed manner to the intermediate shaft 225 in the transition from the interaxle transfer gear 223 to the axle gear 207. This cage 241 accommodates the differential pinions in a conventional manner of which the end-side differential pinion, adjacent to the bevel gear 218, is connected in a rotationally fixed manner to the gear wheel 219, which together with the gear wheel 220 forms the intermediate gear which conveys the drive for the further axles, in this case the axle 204. The opposite, end- 11 side wheel 243 of the differential gear is connected in a rotationally fixed manner to the shaft 209 of the bevel gear 218. If the interaxle differential gear 240 is locked, bevel gear 218 and gear wheel 219 are connected in a rotationally fixed manner, and thus the axles 203 and 204 are also rigidly coupled. If the interaxle differential gear 240 is open, it is possible for there to be a differential in the drive between the axles 203 and 204.

In functional terms, in the illustration in accordance with Figure 5, an interaxle differential gear 340, which is designed as a planetary differential gear and to this extent is of known design, corresponds to the interaxle differential gear 240. The two rear axles 304a and 304b are connected via this interaxle differential gear to the drive for the second axle 303, based on the direction of travel, so that an interaxle differential is now possible for these two rear axles 304a and 304b together with respect to the front axle 303, as described with reference to Figure 4. Since the design in accordance with Figure 5 otherwise corresponds to that in accordance with Figure 3, reference is made to the explanations given with regard to this figure.

Figure 8 and Figure 9 show exemplary embodiments of a modified drivetrain configuration, the designs in accordance with these exemplary embodiments differing only in that in the exemplary embodiment in accordance with Figure 8 only one axle is provided following the two front (in the direction of travel), adjacent axles, which are connected by an interaxle transfer gear, whereas the exemplary embodiment in accordance with Figure 9 provides two such axles. Moreover, in the embodiments in accordance with Figures 8 and 9, the drive train shown, with regard to the two front axles (in the direction of travel), in turn corresponds to that which was explained with reference to the preceding exemplary embodiments, for which reason the description of Figures 8 and 9, like the previous description, uses corresponding reference numerals, but commencing with reference numeral 401 with regard to the illustration in accordance with Figure 8 and commencing with reference numeral 501 with regard to the illustration in accordance with Figure 9.

The vehicle 401, the drive train of which is illustrated diagrammatically in the illustration in accordance with Figure 8, has, based on the direction of travel F, a first axle 402 and a second axle 403, which are connected via an interaxle transfer gear 423.

12 Unlike that which has been described hitherto, the third axle 404, based on the direction of travel F, is provided with a split design. This is understood to mean that the axle gear 408 is arranged offset in the longitudinal direction with respect to the axle plane defined by the wheel centres, and specifically it is situated in proximity to the axle 403 which lies in front of it, based on the direction of travel. While otherwise being configured in accordance with the previous design of axle gear, this axle gear 408 is provided with output shafts 410, 411, which end with bevel gears 450 and 45 1, respectively, which form part of an angle drive, the other bevel gears of which are at 90' to the bevel gears 450 and 451 and are denoted by 452 and 453. These bevel gears 452, 453,the axes of which lie in the longitudinal direction of the vehicle, form the start of a shaft train 454 and 455, respectively, which in each case extends in the longitudinal direction of the vehicle and via which the respective wheel 405 is driven, with the intervention of suitable diverter gears. As diverter gears, an angle drive 456 and 457, respectively, is again provided at the wheel-side end of the shaft train 453, i.e. adjacent to the wheel, which angle drive drives the respective wheel 405 via an intermediate gear with reversing wheel 458 and 459, respectively.

In the configuration in accordance with Figure 9, this basic concept of a split axle drive is now applied to two axles, one of these axles not having a separate axle gear, since in each case two wheels situated one behind the other can be driven via one side shaft train starting from a common axle gear 508, by extending the side shaft trains. In concrete terms, this means that axles 504a and 504b are provided, which are in each case formed by a pair of wheels 505 which lie in a transverse vehicle plane but are assigned a common axle gear, which is offset forwards, in the longitudinal direction of the vehicle, out of the transverse planes of these axles and, as shown for the axle gears 408 and 508, can be moved close to the axle 403 or 503, respectively, which lies in front of it, or can even be flange-coupled to the axle gear of this axle.

The length of the output shafts 410, 411 and 510, 511 of the axle gears 408 makes it possible in a siniple manner to perform the necessary adjustments in the transverse direction of the vehicle.

The use of angle drives 456, 458 and 457, 459, based on the illustration in accordance with Figure 8, provides the additional advantage of being able to align 13 the vertical position of the shaft trains 454 and 455 in accordance with the particular conditions, since the intermediate gears 458 and 459, like portal axles, can be used for vertical compensation depending on their position.

In conjunction with suitable independent wheel guides, such a drive-train design provides very extensive configuration options and, particularly with suitable floor designs of the body, permits a wide variety of possible uses for the body.

Examples of such body shapes are illustrated in Figures 10 to 15, the drive-train configurations indicated with regard to these figures also providing a good illustration of the fact that the mutually adjacent axles which are connected via the interaxle transfer gear and which are assigned the connection to the engine-gearbox unit via the interaxle transfer gear, may be provided both at the front and at the rear of the vehicle, which fact is not illustrated separately in the exemplary embodiments in accordance with Figures 1 to 5.

Based on a drive-train configuration in accordance with Figure 1, the vehicles 610 in accordance with Figure 10 and 620 in accordance with Figure 11 illustrate that the design according to the invention of the drive of the mutually adjacent axles, which are connected to the enginegearbox unit in accordance with Figure 2 via the interaxle transfer gear, allows various positions of the engine-gearbox unit in the transverse direction of the vehicle, including an arrangement above the interaxle transfer gear, thus in the central region of the vehicle, all this with different heights of the body of the vehicle; the illustration in accordance with Figure 11 provides a desired, particularly low silhouette, and the illustration in accordance with Figure 10 increases the loading capacity by raising the silhouette. A low silhouette in accordance with Figure 11 here corresponds to a height of 2.00 m, while a raised silhouette in accordance with Figure 10 corresponds to a height of 2.20 m.

If, as in the vehicle 630 in accordance with Figure 12, an enginegearbox unit is used in which, unlike that in accordance with Figure 2, the output to the interaxle transfer gear is moved to the front side, facing away from the engine, of the gearbox unit, this unit can be moved further to the rear, without changing the design of the drive train, and, as illustrated, the driver can thus sit in the front end of the vehicle, even centrally if appropriate. In conjunction with a relatively high seat position, together with a high silhouette of the vehicle, the driver is thus provided with 14 particularly favourable operating options, irrespective of whether the engine-gearbox unit is arranged centrally or laterally offset with regard to the transverse direction of the vehicle, as is also possible with the embodirnents described above. The configuration of the vehicle 640 in accordance with Figure 13, which illustrates this fact, essentially corresponds to the configuration in accordance with Figure 12, but in Figure 13 the wedge-like nose of the vehicle is of stepped design in the final region, which may be advantageous in particular for vehicles of this type which are used for transportation purposes. The high silhouette produced for the vehicle 640 additionally yields a large transport volume and, depending on the loading state, also provides a weight distribution which ensures good manoeuvrability, owing to the relatively central position of the engine, with respect to the vehicle as a whole.

The vehicles 650 and 660 in accordance with Figures 14 and 15 have the engine arranged at the rear, in conjunction with an arrangement of the adjacent axles which are connected by the interaxle differential gear as the rear axles of the vehicle. Ile drive train design remains the same as that of the drive U-aim in accordance with Figure 1, but the direction of travel is reversed. Such an arrangement is advantageous in particular if a particularly shallow design is desired towards the front, for example in order to be able to position a turret in a favourable location for use as a weapon carrier.

Particularly for those solutions which are illustrated in Figures 14 and 15, it seems appropriate to arrange the cooling system for the vehicle in the rear section, so that the front section of the vehicle is fully available for other purposes. The various arrangements of the enginegearbox unit in conjunction with a drive-train configuration in accordance with the invention demonstrate in a general manner possibilities for designing the vehicle with an extremely low silhouette, so that very different body shapes can be achieved while retaining the same basic structure of the drive train andlor of the engine-gearbox unit, which is an hnportant factor with regard to cost-effective production of a large number of variants.

The latter advantage applies in particular also in conjunction with drivetrain configurations in accordance with Figures 8 and 9, which seem particularly appropriate if it is desired to gain access to the vehicle from the rear with free, clear spaces which are as large as possible.

is

Claims

1. A drive arrangement for all-wheel drive vehicles with at least three axles which have axle drives arranged in the longitudinal centre area of the vehicle, a transmission arranged adjacent the engine and outputting to an interaxle transfer gear, which lies between axle gears of two adjacent axles, and driving the axle gears, which comprise differential gears with wheel drive shafts which lead to the wheels, via in each case one bevel gear which meshes with the ring gear of the differential gear, an intermediate gear, which has a first gear wheel which is coaxial with the bevel gear and a second gear wheel which is situated to the side of and vertically'offset with respect to the bevel gear, is mounted at least partially in front of the differential gears of the axles, wherein the interaxle transfer gear is connected in drive terms coaxially to the bevel gears of the axle gears of the two adjacent axles, and the drive for axles which follow the adjacent axles passes via the intermediate gear of the said following axles and via the intermediate gear of the respectively closer one of the adjacent axles, and the shaft axle connecting the second gear wheels thereof running beneath the drive shafts which run from the differential gears to the wheels.

2. A drive arrangement according to Claim 1, wherein the adjacent axles which are connected via the interaxle transfer gear are the front axles of the vehicle.

3. A drive arrangement according to Claim 1, wherein the adjacent axles which are connected via the interaxle transfer gear are the rear axles of the vehicle.

4. A drive arrangement according to Claim 1 or 2, wherein for the front axle of the vehicle the axle gear is arranged rotated through 180' about a vertical axis with respect to the further axles of the vehicle.

5. A drive arrangement according to any one of the preceding claims, wherein, based on a vehicle with at least three axles and front axles which are connected via the interaxle transfer gear, the second and following axle(s) are connected via an interaxle differential gear.

16

6. A drive arrangement according to Clahn 5, wherein the interaxle differential gear is a locking differential.

7. A drive arrangement according to Clahn 5 or 6, wherein the interaxle differential gear is mounted in front of the bevel gear of the axle gear of the second axle.

8. A drive arrangement according to any one of Claims 5 to 7, wherein the interaxle differential gear comprises a bevel-gear differential.

9. A drive arrangement according to any one of Claims 5 to 7, wherein the longitudinal differential gear comprises a planetary gear system.

10. A drive arrangement according to any one of the preceding claims, wherein the axle gear of at least one axle is provided with a differential lock.

11. A drive arrangement according to any one of the preceding claims, wherein, after missing my exit from their bath the second and subsequent axles of the vehicle are provided with interaxle differential locks.

12. A drive connection for all-wheel drive vehicles with at least three axles which have axles drives, a transmission arranged behind the engine and outputting to an interaxle transfer gear, which lies between axle gears of two adjacent axles, and driving the axle gears, which comprise differential gears via in each case one bevel gear which meshes with the ring gear of the axle gear, an intermediate gear, which has a first gear wheel which is coaxial with the bevel gear and a second gear wheel which is situated to the side of and vertically offset with respect to the bevel gear, is mounted at least partially in front of the differential gears of the axles, wherein the interaxle transfer gear is connected in drive terms to the bevel gears of the adjacent axle gears and the drive for the axle which follows the adjacent axles is effected via the intermediate gear of the said following axle and the intermediate gear of the respectively closer one of the adjacent axles, the axle which follows the adjacent axles being of split design, in 17 such a manner that the axle gear of this axle is offset out of the axle plane, in the longitudinal direction of the vehicle, towards the next axle in front of it and is connected in drive terms to the associated wheels via side shaft trains which run in the longitudinal direction of the vehicle.

13. A drive arrangement according to Claim 12, wherein the axle gear which is offset out of the axle plane is arranged close to the next axle in front of it, is arranged directly adjacent to the latter.

14. A drive arrangement according to Claim 12 or 13, wherein the axle gear which is offset out of the axle plane is connected via an angle drive to the shaft train running in the longitudinal direction of the vehicle.

15. A drive arrangement according to any one of Claims 12-14, wherein the shaft train comprises one or more cardan shafts.

16. A drive arrangement according to Claim 15, wherein the shaft train is connected via an angle drive to the wheel (405) to be driven.

17. A drive arrangement according to Claim 16, wherein an intermediate gear is arranged behind the angle gear (456, 457) arranged behind the shaft train.

18. A drive arrangement according to any one of Claims 12-17, wherein the axles of the shafts in the drive between the intermediate gear of the axle which immediately follows the adjacent axles and that one of the adjacent axles which is closer to this immediately following axle runs beneath the shafts which run from the axle gear of this axle to the wheels.

19. A drive arrangement according to any one of Claims 12 to 17, wherein the axle of the shaft in the drive between the intermediate gear of the axle which immediately follows the adjacent axles and that one of the adjacent axles which lies closer to this 18 immediately following axle, runs above the shafts which run from the axle gear of this axle to the wheels.

20. A drive arrangement according to any one of Claims 12-19, wherein a further axle is arranged behind the axle which follows the adjacent axles, and, in a split design with axle gear offset out of the axle plane, this axle gear is provided as a common axle drive for these two axles, and the wheels of the two axles, on each side of the vehicle, are in each case connected jointly in drive terms via a side shaft train which runs in the longitudinal direction of the vehicle.

21. A drive arrangement substantially as described herein with reference to, and as illustrated in, the accompanying drawings.