Automatic Transmission (AT), Function
Automatic transmission 722.6 is an electronically controlled 5speed transmission with a lockup clutch in the torque converter. The ratios for the gears are realized by three planetary gear sets. The 5th gear is designed with a step-up ratio as an overdrive. Shifting is initiated electronically. The gears are shifted by the corresponding combination of three hydraulically actuated multiplate brakes, three hydraulically actuated multi-disc clutches and two mechanical freewheels.
Automatic transmission 722.6 with electronic control offers the following advantages:
Reduced fuel consumption
Improved ease of shifting
More convenient position due to 5 gears
Extended working life and reliability
Lower maintenance costs
The torque converter housing and transmission housing are made of a metal alloy. They are screwed together and centered via the externally toothed disk carrier of the multi-plate brake B1. A coated intermediate panel seals the two components.
Both the oil pump and the externally toothed disk carrier of the multi -plate brake B1 are screwed to the torque converter housing. The mechanical part consists of the propeller shaft, output shaft, a sun gear shaft and three planetary gearsets which are coupled together.
In transmissions for powerful engines, the planetary gearsets have 4 planetary gears, while for less powerful engines the front and rear planetary gear system has three planetary gear wheels. The stator shaft is pressed into these planetary gear wheels and is secured against twisting by gearing.
The electrohydraulic control unit is screwed onto the transmission housing from underneath. An oil pan made of sheet steel is also connected.
The oil pressure of the torque converter lockup dutch and clutch K2 is supplied via bore holes in the propeller shaft. The oil pressure to dutch K3 is supplied via the output shaft. The lubricating oil is supplied and distributed by additional bore holes in both shafts. Oil is supplied to all bearing points of the gearsets as well as to the freewheels and shifting elements.
The parking lock gear and drive flange are connected to the output shaft by gearing.
Freewheels F1 and F2 optimize shifting. The front freewheel is held against the stator shaft extension on the transmission side and connects the sun gear of the front planetary gearset to the transmission housing in the locking direction. The rear freewheel connects the sun gear of the center planetary gearset to the sun gear of the rear planetary gearset in the locking direction.
The electrohydraulic control unit consists of the shift plate made of light alloy for hydraulic control and an electronic control unit. The electronic control module consists of a plastic shell which combines all the electric components. The shell is screwed to the shift plate. Conductor tracks which are integrated into the shell connect the electronic components to a plug connector. This 13 pin plug connector connects the vehicle-side cable harness to the ETS control unit (electronic transmission control) via a bayonet lock.
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