Drive system for a motor vehicle with a drive unit and electric machine, and method of operating the system

A drive system for a motor vehicle, comprising

• a combustion engine (1) as the drive system,
• a drive train (2) for torque transmission from the combustion engine (1) to drive wheels (3) by means of a drive shaft (10) driven by the combustion engine (1) and an output shaft (55),
• a lock-up clutch (60) between the drive shaft (10) and the output shaft (55),
• an electrical machine (4) in the drive train (2) having at least two electromagnetic active units--a rotor (9) an a stator (8),
• wherein the rotor (9) is connected with one of the two shafts--the output shaft (55) or the drive shaft (10)--in a rotationally fixed manner and the lock-up clutch (60) is arranged between the rotor (9) and the other of the two shafts (10 or 55, respectively), and
• wherein the stator (8) is either
• i) in a first coupling state in which it is coupled with the other of the two shafts (10 or 55, respectively) in a rotationally fixed manner, thereby rotating together with such shaft (10 or 55, respectively), or
• ii) in another coupling state in which it is disengaged from the other of the two shafts (10 or 55, respectively) and fixed against rotation,
• wherein the combustion engine (1) transfers its torque in the first coupling state and in case the lock-up clutch (60) is open to the drive wheels (3) via the electrical machine (4), with the latter then acting as an electromagnetic clutch, wherein, in the other coupling state, the combustion engine (1) transfers its torque via the then closed lock-up clutch (60) to the drive wheels (3), with the electrical machine (4) additionally applying torque to the then connected drive and output shafts (10, 55).

A procedure to operate a drive system for a motor vehicle, with a combustion engine (1) as the drive system, a drive train (2) for torque transmission from the combustion engine (1) to drive wheels (3), having a drive shaft (10) driven by the combustion engine (1) and an output shaft (55), with the following characteristics:

• a lock-up clutch (60) is arranged between the drive shaft (10) and the output shaft (55),
• in the drive train (2), an electrical machine (4) is arranged which has at least two electromagnetic active units--a rotor (9) and a stator (8), wherein the rotor (9) is connected with one of the two shafts--the output shaft (55) or the drive shaft (10)--in a rotationally fixed manner and the lock-up clutch (60) is positioned between the rotor (9) and the other of the two shafts (19.sup.1 or 55, respectively), and
• the stator (8) is operated either
• i) in a first coupling state in which it is coupled with the other of the two shafts (10 or 55 respectively) in a rotationally fixed manner, thereby rotating together with such shaft (10 or 55, respectively), or
• ii) in another coupling state in which it is uncoupled from the other of the two shafts (10 or 55, respectively) and fixed against rotation,
• wherein the combustion engine (1) transfers its torque in the first coupling state and in case the lock-up clutch (60) is open to the drive wheels (3) via the electrical machine (4), with the latter then acting as an electromagnetic clutch,
• wherein, in the other coupling state, the combustion engine (1) transfers its torque via the then closed lock-up clutch (60) to the drive wheels (3), with the electrical machine (4) additionally applying torque to the then connected drive and output shafts (10, 55).

A procedure for operating a drive system for a motor vehicle, comprising a combustion engine (1) as the drive system, a drive train (2) for torque transmission from the combustion engine (1) to drive wheels (3) with a drive shaft (10) driven by the combustion engine (1) and an output shaft (55), with the following characteristics:

• a lock-up clutch (60) is arranged between the drive shaft (10) and the output shaft (55),
• in the drive train (2), an electrical machine (4) is arranged which has at least two electromagnetic active units--a rotor (9) and a stator (8), wherein the rotor (9) is connected with one of the two shafts--the output shaft (55) or the drive shaft (10)--in a rotationally fixed manner and the lock-up clutch (60) is arranged between the rotor (9) and the other of the two shafts (10 or 55, respectively), and
• wherein the stator (8,8') is provided as a double unit whose
• i) first partial unit (8') is coupled in a rotationally fixed manner with the two shafts (10 or 55, respectively), and
• ii) whose other partial unit (8) is not coupled with the other of the two shafts (10 or 55, respectively) and rather fixed against rotation,
• wherein always one of the two partial units (8', 8) is electromagnetically activated and the other deactivated, and
• wherein in case the first partial unit (8') is active and the lock-up clutch (60) is open, the combustion engine (1) transfers its torque to the drive wheels (3) via the electrical machine (4), with the latter then acting as an electromagnetic clutch,
• wherein, in case the second partial unit (8') is active, the combustion engine (1) transfers its torque via the then closed lock-up clutch (60) to the drive wheels (3), with the electrical machine (4) additionally applying torque to the then connected drive and output shafts (10, 55).