The drive device serves, for example, to supply a drive torque for carrying out a driving operation of the motor vehicle. The drive device is therefore preferably a component of the motor vehicle. The drive device provides the at least one drive assembly, which, for example, is designed as an internal combustion engine or as an electric motor. Obviously, the drive device can also have a plurality of drive assemblies, which, in this case, are preferably of differing type. Thus, a first drive assembly can be designed as an internal combustion engine and a second drive assembly as an electric motor.
The drive assembly is operatively connected or can be operatively connected via the gearbox to at least one drivable axle of the motor vehicle. Preferably, a clutch is present in the operative connection between the drive assembly and the at least one axle, in particular a starting clutch. The starting clutch is provided, for example, between the drive assembly and the input shaft of the gearbox. This means that, by means of the clutch, the operative connection between the drive assembly and the gearbox or the input shaft thereof can be alternatively engaged or disengaged.
By contrast, the at least one drivable axle of the motor vehicle is preferably operatively connected rigidly and/or permanently to the gearbox, in particular to an output shaft of the gearbox. This means that the output shaft is always rotating when drive operation of the motor vehicle is carried out, that is, for a speed of the motor vehicle that is different from zero.
With the aid of the gearbox, preferably a plurality of driving gears can be engaged in the form of mutually differing gear ratios between the input shaft and the output shaft of the gearbox. The driving gears comprise, for example, a plurality of forward gears as well as at least one, in particular exactly one, reverse gear. The different driving gears or gear ratios are realized with the aid of the gear set of the gearbox. The gear set has insofar, for example, one pair of gears for each driving gear, in particular one pair of toothed gears.
On account of the friction existing in the gearbox or in the gear set, in particular during drive operation of the motor vehicle, heat is produced. This heat needs to be dissipated in order to keep the temperature of the gearbox or of the gear set within allowable limits. In addition, a lubrication of the gear set is necessary. For this reason, lubricant is supplied to the gear set. This means that at least one gear, in particular a toothed gear wheel, of the gear set is supplied with the lubricant, preferably directly. More preferably, a plurality of, and in particular all gear wheels, of the gear set are supplied with the lubricant, in particular directly.
For example, the gear set can be lubricated or cooled by means of immersion lubrication. In the process, in simple terms, sufficient lubricant is poured into the gearbox until, for all pairs of gears, at least one gear wheel is immersed in the lubricant in each instance, preferably by several millimeters. However, this leads to a part of the gear wheels being immersed markedly deeper in the lubricant than is the case for other gear wheels. This leads to relatively high losses due to splashing.
Additionally or alternatively, the lubricant is supplied to at least one of the gear wheels directly. A direct supply of lubricant is to be understood in this case to mean, for example, that the lubricant issues downstream of the primary lubricant pump from an outlet point, in particular a nozzle, and, in doing so, is directed directly at the respective gear wheel. This is referred to as injection lubrication. With the aid of the injection lubrication, it is possible in theory to completely prevent any splashing.
Conveyance of the lubricant is provided with the aid of the primary lubricant pump. For example, this represents the sole conveying means for lubricant that is associated with the gearbox, in particular the gear set thereof. Lubricant is insofar conveyed to the gear set solely by means of the primary lubricant pump.
USPTO Backgrounds
USPTO Backgrounds