PTM Function

PTM Function

One torque distribution in each case is calculated and summed in parallel in the PTM control unit from different input information. This results in a requested, summed torque distribution which is checked once more in the control unit and reduced again depending on the driving situation and/or ambient conditions. The actual setpoint torque distribution is then calculated and a pulse-width-modulated signal generated from this. This signal is used to control the solenoid (5) in the PTM clutch.







When the solenoid (5) is energized, the active pick-up plate (8) is pulled towards the primary clutch (7), thereby generating a torque in the clutch. The support element (4) provides the support required. The pickup plate (8) is referred to as "active" because it simultaneously functions as a friction plate, which has the advantage that more torque can be transferred. The ball ramp (3) turns when a torque is generated in the primary clutch (7), thereby actuating the main clutch and producing a controlled frictional connection between the drive shaft (6) and output shaft (1).







The advantage of this arrangement of primary clutch (which is controlled) and main clutch (which transfers the torque) is that the primary clutch is operated with a small current and only a small force is necessary in order to operate a large clutch capable of transferring a large force. For this reason, the reaction time of this system is also very short. This system can be compared with a working relay which switches a high working current with a small control current.

Lubrication







An oil pump is driven by the gearing of the output shaft. This oil pump supplies the plate assemblies with lubricating oil. The oil is sucked in through the oil suction snorkel in the oil sump and are supplied from there to the hollow output shaft. The output shaft is provided with cross bores to permit targeted lubrication.

Temperature Sensor







A temperature sensor (arrow) is screwed into the housing and measures the oil sump temperature directly so that the oil temperature in the clutch housing can be transmitted to the PTM control unit. If the oil temperature reaches a critical level, various measures are implemented in different stages in order to prevent clutch overheating. Diagnostics The PTM control unit is diagnostics-capable and can be read out with the PIWIS Tester.