BMW F97, Техническое учебное пособие

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F97/F98�Complete�Vehicle
4.�Powertrain
35
Index Explanation
6 Axial�needle�bearing
7 Axial�bearing�thrust�washer
8 Circlip�(ball�bearing�fixing)
9 Ball�bearing�between�inner�output�hub�and�differential�housing
10 Disc�spring�pressure�ring
11 Disc�spring
12 Differential�lid�(connected�to�differential�housing,�cannot�rotate)
13 Pressure�plate
14 Disc�set
15 Counter�pressure�plate
16 Output�bevel�gear
17 Output�bevel�gear
18 Differential�housing�(connected�to�outer�discs)
The�electric�motor�(1)�is�bolted�onto�the�housing�and�the�pressure�plate�fixed�to�the�2nd�half�of�the�ball
ramp�(5)�in�the�housing.�The�mobile�components�of�the�ball�ramp�(2,�3�and�4)�generate�the�necessary
axial�displacement�of�the�pressure�disc�(5).�These�components�are�not�subject�to�the�differential
transmission�rotation�and�are�disconnected�from�the�rotating�components�by�an�axial�needle�bearing
(6).
The�components�with�the�index�6�to�18�belong�to�the�differential�and�rotate�proportional�to�the�rear
axle�gear�speeds.
The�lock�is�effected�between�the�right�output�(16)�and�the�differential�housing�(18)�and�counteracts�a
difference�in�speed�between�the�output�bevel�gears�(16�and�17).�The�disc�spring�(11)�opens�the�lock
when�the�engine�is�not�supplied�with�current.
4.3.7.�System�information
The�M�DSC�control�unit�evaluates�the�dynamic�handling�characteristics�parameters�made�available
by�other�control�units�via�the�FlexRay�data�bus�and�determines�the�lock-up�torque�to�be�applied.�The
M�DSC�control�unit�can�also�request�separate�and�higher-level�locking�interventions�to�stabilize�the
vehicle�both�when�the�M�DSC�is�activated�and�deactivated.
The�position-controlled�direct�current�motor�is�activated�directly�by�the�power�electronics�of�the
M�GHAS�control�unit�with�vehicle�voltage�via�a�pulse-width-modulated�signal.�The�frequency�is
approximately�4�kHz�and�the�maximum�current�level�is�30�A.
To�determine�the�position�and�the�direction�of�rotation�of�the�electric�motor�it�is�equipped�with�2�hall
effect�sensors.