Power split transmission, method of operating a power split transmission and motor vehicle with a power split transmission

A method for operating a power split transmission comprising a drive shaft, a first mechanical branch, a planetary gear arrangement with at least two sun gears, a first ring gear and a planetary web on which double planetary gears are arranged, which mesh with the sun gears and with the first ring gear, at least one of the sun gears being coupled to the drive shaft, a continuously variable second branch which can be connected at least partially to the first mechanical branch via the planetary gear arrangement and comprises at least two adjustable hydraulic units which can be energetically coupled to one another and can be operated in each case in both directions as a motor or pump, and an output shaft which can be coupled to the drive shaft via the first mechanical branch and the second branch, wherein the planetary gear arrangement includes a planetary reversing gear by which the direction of rotation of the first mechanical branch can be reversed, wherein the planetary reversing gear has an axially adjustable shift sleeve, wherein in a first axial position, the shift sleeve transmits the direction of rotation of the planetary web directly to a reversing planet which, in the first mechanical branch, is non-positively connected to a summing shaft by way of three gear wheels including a first gear wheel associated with a coupling shaft of the first mechanical branch and a second adjacent gear wheel, and wherein in a second axial position, the shift sleeve is directly or indirectly blocked against rotation relative to a gear housing of the power split transmission, such that the direction of rotation of the planetary web is reversed and acts with a reversed direction of rotation on the summing shaft, wherein the power of the first mechanical branch and the second branch are combined via the summing shaft, wherein the method comprises:

• in a forward driving range, displacing the shift sleeve into the first axial position which is not fixed in terms of rotation relative to the transmission housing,
• wherein a first hydraulic unit of the two hydraulic units is coupled to the first ring gear via a first gear wheel and a second gear wheel on an outer rim of the first ring gear,
• wherein a second hydraulic unit of the two hydraulic units is coupled to a summing shaft via a first clutch, a third gear wheel and a fourth gear wheel,
• wherein the first hydraulic unit is pivoted from a pivoting position with a pivoting angle of 0° in a first pivoting direction into a positive angular range and is operated as a pump, and
• wherein the second hydraulic unit is operated as a motor.

A method for operating a power split transmission comprising a drive shaft, a first mechanical branch, a planetary gear arrangement with at least two sun gears, a first ring gear and a planetary web on which double planetary gears are arranged, which mesh with the sun gears and with the first ring gear, at least one of the sun gears being coupled to the drive shaft, a continuously variable second branch which can be connected at least partially to the first mechanical branch via the planetary gear arrangement and comprises at least two adjustable hydraulic units which can be energetically coupled to one another and can be operated in each case in both directions as a motor or pump, and an output shaft which can be coupled to the drive shaft via the first mechanical branch and the second branch, wherein the planetary gear arrangement includes a planetary reversing gear by which the direction of rotation of the first mechanical branch can be reversed, wherein the planetary reversing gear has an axially adjustable shift sleeve, wherein in a first axial position, the shift sleeve transmits the direction of rotation of the planetary web directly to a reversing planet which, in the first mechanical branch, is non-positively connected to a summing shaft by way of three gear wheels including a first gear wheel associated with a coupling shaft of the first mechanical branch and a second adjacent gear wheel, and wherein in a second axial position, the shift sleeve is directly or indirectly blocked against rotation relative to a gear housing of the power split transmission, such that the direction of rotation of the planetary web is reversed and acts with a reversed direction of rotation on the summing shaft, wherein the power of the first mechanical branch and the second branch are combined via the summing shaft, wherein the method comprises:

• in a reverse travel range, moving the shift sleeve into the second axial position in which the shift sleeve is fixed against rotation relative to the transmission housing,
• wherein a first hydraulic unit of the two hydraulic units is operated as a pump and a second hydraulic unit of the two hydraulic units is operated as a motor, and
• wherein the first hydraulic unit is pivoted from a pivoting position of 0° into a second pivoting direction into a negative angular range.