Drive unit for a vehicle, and operating method therefor

A method of operating a drive device for a vehicle, having an internal combustion engine (VM) and a transmission, designed as a multistage manual transmission (SG) having first and second sub-transmissions (TG1, TG2);

• the first sub-transmission having a first transmission input shaft (GE1);
• the second sub-transmission having a second transmission input shaft (GE2);
• the first transmission input shaft (GE1) of the first sub-transmission (TG1) is assigned a first clutch (K1, K1′) by which the first transmission input shaft (GE1) is either drivingly connectable to the internal combustion engine (VM), or is assigned an electric machine (EM);
• the second transmission input shaft (GE2) of the second sub-transmission (TG2) is assigned a second clutch (K2) by which the second transmission input shaft (GE2) is drivingly connectable to the internal combustion engine (VM);
• and
• the method comprising the steps of:
• implementing at least one hydrodynamic start-up function by a start-up element (AR, AR′, AR″), the start-up element (AR, AR′, AR″) being assigned to the first transmission input shaft (GE1) and comprising at least one hydrodynamic transfer element (HK, HD, HB) comprising a first functional wheel (FR1, STa, STb) and a second functional wheel (FR2, RT) which together form a working chamber (FL, FLa, FLb) for receiving fluid in order to generate a hydrodynamic transfer torque;
• wherein the at least one hydrodynamic transfer element (HK) and a planetary gear set (PS) are coupled to one another so as to form one unit;
• implementing the start-op function by the start-up element (AR) which is embodied as a start-up retarder, the start-up retarder (AR) comprises the at least one hydrodynamic transfer element (HK) having a first rotatable functional wheel (FR1) and second rotatable functional wheel (FR2), the planetary gear set (PS) has a ring gear (HR), a sun gear (SR), and a planet carrier (PT), which rotationally supports a plurality of planetary gears (PR) that mesh with the sun gear (SR) and the ring gear (HR), and a shift element (B),
• building a hydrodynamic transfer torque with the start up retarder by filling the working chamber (FL) with fluid, one of the ring gear (HR) or the sun gear (SR)of the planetary gear set functions as a drive element of the planetary gear set (PS), which is driven by a drive motor (VM, EM), the other of the ring gear (HR) or the sun gear (SR) of the planetary gear set, that is connected in a rotationally fixed manner to the first functional wheel (FR1) and is fixable to a rotationally fixed component by a shift element (B), is fixed via engagement of the shift element (B) when a speed of rotation of the planetary gear set element crosses zero, and the planet carrier (PT), which is connected in a rotationally fixed manner to the second functional wheel (FR2), functions as an output element of the planetary gear set (PS) and drives the first transmission input shaft (GE1) of the first sub-transmission (TG1).

A drive device for a vehicle comprising:

• an internal combustion engine (VM);
• a multistage manual transmission (SG) having a first transmission input shaft (GE1), and a second transmission input shaft (GE2);
• a clutch module (EM/X/K, DK) drivingly coupling the first transmission input shaft (GE1) to the internal combustion engine (VM) via either a first clutch (K1, K1′) or a coupling shift element (X), and the clutch module (EM/X/K, DK) drivingly couples the second transmission input shaft (GE2) to the internal combustion engine (VM) via either a second clutch (K2) or a hybrid clutch (K);
• a start-up element (AR, AR′, AR″) being drivingly connected to the first transmission input shaft (GE1), the start-up element (AR, AR′, AR″) having a hydrodynamic transfer element (HK, HD, HB) and a planetary gear set (PS) coupled to one another so as to form a single unit;
• the hydrodynamic transfer element having a first functional wheel (FR1, STa, STb) and a second functional wheel (FR2, RT), the first and the second functional wheels together forming a working chamber (FL, FLa, FLb) which fills with fluid to generate a hydrodynamic transfer torque such that at least one start-up function, transferred only to the first sub-transmission (TG1), is implemented by the start-up element (AR, AR′, AR″);
• and
• the second transmission input shaft (GE2) is drivingly disconnected from the at least one hydrodynamic transfer element (HK) and drivingly directly connected to either the second clutch (K2) or the hybrid clutch (K) such that the hydrodynamic transfer torque generated by the at least one hydrodynamic transfer element (HK) is not transferred to the second sub-transmission (TG2);
• first and second countershafts (VW1, VW2), are disposed coaxially over one another and are drivingly connected to a respective one of the first and the second transmission input shafts (GE1, GE2) by one gear set (EK, G6) having two meshing gearwheels;
• both of the first and the second countershafts (VW1, VW2) are associated with at least three gear sets (G1, G2, G3, G4, G6 G5, G7, EK, RG);
• one of a ring gear (HR) or a sun gear (SR) of the planetary gear set is connected, in a rotationally fixed manner, to the first functional wheel (FR1) of hydrodynamic transfer element (HK) and is fixable, by a shift element (B, UK), to a stationary component (GH);
• another of the ring gear (HR) or the sun gear (SR) of the planetary gear set is connected, in a rotationally fixed manner, to one of a drive shaft (AN_EM) of an electric machine (EM), a drive shaft (K1_AN) of the first clutch (K1), or an input shaft (K2′_AN) of the second clutch (K2′);
• and
• the start-up, element (AR, AR′, AR″) is arranged on the first transmission input shaft (GE1) downstream of the clutch module and upstream of the first sub-transmission (TG1).