Internal-Gear Pump and Hydraulic Circuit for a Motor Vehicle Drivetrain

A hydraulic circuit comprising an internal-gear pump, the internal-gear pump having:

• a housing which has a first fluid port and a second fluid port;
• an inner rotor which is mounted in the housing so as to be rotatable about an inner rotor axis and which has an external toothing;
• an outer rotor which is rotatable in the housing about an outer rotor axis and which has an internal toothing which, to generate a pump action, engages with the external toothing of the inner rotor;
• and
• a ring element which is mounted movably in the housing and which is pivotable between a first position and a second position;
• wherein at least a third fluid port is formed on the housing, wherein the third fluid port is arranged relative to the ring element such that, in the first position of the ring element, the third fluid port is connected to the second fluid port, and in the second position, said third fluid port is separated from the second fluid port.

A hydraulic circuit which comprises an internal-gear pump, having:

• a housing which has a first fluid port and a second fluid port;
• an inner rotor which is mounted in the housing so as to be rotatable about an inner rotor axis and which has an external toothing;
• and
• an outer rotor which is rotatable in the housing about an outer rotor axis and which has an internal toothing which, to generate a pump action, engages with the external toothing of the inner rotor.