BMW F97 Technical Training Manual page 39

F97/F98￿Complete￿Vehicle
4.￿Powertrain
Index
6
7
8
9
10
11
12
13
14
15
16
17
18
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.
Explanation
Axial￿needle￿bearing
Axial￿bearing￿thrust￿washer
Circlip￿(ball￿bearing￿fixing)
Ball￿bearing￿between￿inner￿output￿hub￿and￿differential￿housing
Disc￿spring￿pressure￿ring
Disc￿spring
Differential￿lid￿(connected￿to￿differential￿housing,￿cannot￿rotate)
Pressure￿plate
Disc￿set
Counter￿pressure￿plate
Output￿bevel￿gear
Output￿bevel￿gear
Differential￿housing￿(connected￿to￿outer￿discs)
35