Drive system for tandem axles

#Tandem axles are often used in working machines such as graders and forest tractors. On each side of the mid-section of an axle, a tandem housing carrying the driving wheels is connected. A differential and rear-mounted service brakes are often situated in the mid-section of the axle. The wheels on the front axle, such as in graders, are often driven by hydrostatic engines.

#DE 41 20 801 C2 discloses a drive system for tandem axles where one axle mid-section always supports the tandem housing and has one differential and service brakes. On the tandem housings, wheel hubs are held which accommodate the driving wheels. The differential, which is located in the mid-section of the axle, is driven via a universal shaft. The transportation and installation of said whole tandem axle, which consists of the axle mid-section and the two tandem housings, is very costly and when said tandem axle is used in different vehicles each time at least the axle mid-section has to be changed.

#The problem on which this invention is based is to provide a drive system for tandem axles which stands out by a compact mounting and a simple assembly in the vehicle.

#Other features are to be understood from the description of the figures which show:

#FIG. 1 is a spatial representation of the arrangement of the drive system; and

#FIG. 2 is a diagrammatic arrangement of the differential of the service brake and planetary gears.

#FIG. 1:

#A prime mover 1 drives a reduction gear 2. In the reduction gear 2 is a front drive, not shown, which makes it possible to dispose the output of the gear above the height of the tandem housing 3. The reduction gear 2 has a housing part 4, on its output, which is either connected with the main housing of the reduction gear 2 or made integrally with it. At least one differential and service brakes are situated in the housing part 4. The output of the housing part 4 is connected with the drive train in the tandem housings 3 via universal shafts 5. The tandem housings 3 are supported directly by a chassis of the vehicle (not shown). A compact drive system for tandem axles is thus provided in which the reduction gear 2 is disposed between the tandem housings 3 and in which the prime mover 1 can be situated above the tandem housing 3 and thus a compact drive results in the longitudinal direction and in the transverse direction.

#FIG. 2: