This application claims priority from German patent application serial no. 10 2019 218 413.8 filed Nov. 28, 2019.

FIELD OF THE INVENTION

The invention relates to a drive arrangement of a vehicle and to a method for carrying out gearshifts.

BACKGROUND OF THE INVENTION

In the older application with file number 10 2019 202 994.9 a drive unit for an electronic vehicle with an electric machine and a three-step or two-step change-speed transmission is disclosed, in which a shifting device with three or two shifting elements for engaging three or two gears is provided. By omitting one shifting element the three-gear transmission can be used as a two-gear transmission. The transmission has two planetary gearsets coupled to one another, such that the first planetary gearset is driven by way of its sun shaft (the transmission input shaft) by the electric machine, while the ring gear of the first planetary gearset is held fixed. The first planetary gearset is coupled by way of its carrier shaft to the ring gear of the second planetary gearset. The carrier shaft of the second planetary gearset forms the transmission output shaft. The three, or two shifting elements are integrated in a sliding sleeve which can move axially on the sun shaft of the second planetary gearset, so that for the three-gear transmission there are a total of five positions, namely three shifting positions and two neutral positions. In the older application a drive axle with drive wheels is also disclosed, in which the drive unit serves as the drive input and drives an axle differential arranged between the drive wheels. The transmission output shaft of the drive unit is thus connected to the differential input, the differential cage. With this drive axle, which comprises only one electric drive machine, only one change-speed transmission and one axle differential, powershifts are not possible. Due to the shifting elements, which are in the form of claws, the shifts take place with traction force interruption.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a drive arrangement which has three gears, in order thereby to be able to meet various vehicle demands relating to torque and drive power. The invention comprises the characteristics specified in the independent claims. Advantageous design features emerge from the subordinate claims.

A drive arrangement for a vehicle with a change-speed transmission having a transmission input shaft and a transmission output shaft is proposed, the transmission being designed as a three-gear transmission for engaging a first gear, a second gear and a third gear, and comprising a first shifting element, a second shifting element and a third shifting element and two planetary gearsets coupled to one another. The first planetary gearset comprises a first sun shaft, a first ring gear shaft and a first carrier shaft, whereas the second planetary gearset comprises a second sun shaft, a second ring gear shaft and a second carrier shaft. The first carrier shaft is permanently connected to the second ring gear shaft. The first sun shaft forms the transmission input shaft. The second sun shaft is held fast on the housing. The second carrier shaft forms the transmission output shaft. To engage the first gear the first shifting element can be actuated. To engage the second gear the second shifting element can be actuated, and to engage the third gear the third shifting element can be actuated.

By means of the first shifting element the first ring gear shaft can be coupled to the housing. By means of the second shifting element the first ring gear shaft can be coupled to the second carrier shaft.

The first planetary gearset is or can be blocked by actuating the third shifting element, whereby the first ring gear shaft can be coupled to the first sun shaft or transmission input shaft, or whereby the first ring gear shaft can be coupled to the first carrier shaft.

The shifting elements can be in the form of disk clutches or unsynchronized claw clutches. Also, the first and second shifting elements can be in the form of claw clutches and the third shifting element only in the form of a disk clutch.

In this case the shifting elements can be single shifting elements, or two of the shifting elements can be combined in a double shifting element. A triple shifting element, in which the first, second and third shifting elements are actuated by a sliding sleeve, is also possible. Preferably, the sliding sleeve of the double shifting element or the triple shifting element is arranged and able to move on the first ring gear shaft.

A method is also proposed for carrying out shifts under load by means of the first, second and third shifting elements of the change-speed transmission, for an upshift under traction from the first gear to the second gear. In this case, in the first gear the first shifting element is closed and the second and third shifting elements are open. The third shifting element is closed with slip until the first shifting element becomes free from load and is opened. Thereafter the third shifting element is closed farther until the second shifting element is synchronized and can be closed. After that, the third shifting element can be opened again.

To upshift from the second to the third gear, the second shifting element being closed in the second gear whereas the first and third shifting elements are open, the third shifting element is closed with slip until the second shifting element becomes free from load and is opened. Thereafter, the third shifting element is closed completely.

When a double shifting element is used, the open position of the first shifting element and the open position of the second shifting element provide neutral positions of the double shifting element.

Actuation can take place by means of ball ramps actuated by electric motor.

