The invention concerns a hybrid drive assembly of a motor vehicle.
From DE 10 2008 000 953 A1 by the present applicant a parallel hybrid drive assembly for a vehicle is known, wherein a planetary gearset is connected between an electric machine and a main transmission. The three-part planetary gearset, which comprises a sun gear, a carrier or planetary carrier and a ring gear, serves mainly as a rotational direction reversal device for obtaining a reverse gear, since the main transmission does not have a reverse gear. In the planetary gearset, which is arranged on the transmission input side, the carrier or planetary carrier is fixed; the rotor of the electric machine is connected to the sun gear and the drive output ring gear is coupled to the transmission input shaft. Thus, the rotor drives the transmission input shaft by way of a fixed transmission ratio of the planetary gearset, so that a rotational direction reversal takes place.
The purpose of the present invention, in a hybrid drive assembly of the type mentioned to begin with, is to achieve a further improvement of the drive behavior, in particular an adaptation of the electric machine to the rotational speed of the transmission input shaft.
The objective of the invention is achieved by the characteristics and advantageous design features as discussed below.
According to the invention, it is provided that the carrier of the planetary gearset is coupled to the transmission input shaft and the ring gear is held fixed. Thus, a fixed transmission ratio of the planetary gearset acts between the electric machine and the transmission input shaft. When the electric machine is working in motor mode, the rotational speed of the rotor is converted to slow speed by the fixed transmission ratio; during overdrive operation, when the electric machine is working as a generator, the rotational speed of the transmission input shaft is increased to high speed by the fixed transmission ratio. The fixed transmission ratio does not produce a rotational direction reversal.
According to a preferred embodiment the rotor is arranged on a rotor carrier, which is supported in the housing by a fixed bearing. Thus, the rotor is fixed relative to the housing in the radial and axial directions.
In a further preferred embodiment, the carrier of the planetary gearset has a cylindrical neck which is connected to the transmission input shaft in a rotationally fixed and non-pivoting manner. Preferably, the neck is connected rotationally fixed to the transmission input shaft by spline teeth in the form of a fixed seating and secured against pivoting by a centering seat. Thus, the carrier is connected virtually solidly to the transmission input shaft.
In a further preferred embodiment, the carrier—by way of the transmission input shaft—is mounted statically fixed, this being by virtue of a first bearing in the form of a fixed bearing preferably arranged on the housing of the main transmission and by a second bearing in the form of a loose bearing, a so-termed pilot bearing, in the area of the internal combustion engine.
According to a further preferred embodiment, the carrier is connected to a bolt carrier which is preferably supported relative to the rotor carrier by a needle bearing. Thus, the rotor carrier is mounted in two ways, namely on the one hand by the fixed bearing and on the other hand by the needle bearing.
In a further preferred embodiment, the rotor carrier is connected to the sun gear by spline teeth, wherein the inner teeth of the rotor carrier and the outer teeth of the sun gear can move axially relative to one another. Thus, the rotor carrier can be installed by pushing it into place in the axial direction.
In a further preferred embodiment, the sun gear has a cylindrical neck at the end of which the spline teeth are arranged and the torque can be transmitted.
According to a further preferred embodiment, the neck of the sun gear extends radially into the hub of the rotor carrier. This has the advantage of being a space-saving design: the planetary gearset can be fitted in a “fitting-space-neutral” way, i.e. without taking up additional space inside the rotor.
In a further preferred embodiment, the sun gear is integrated with the rotor carrier, i.e. the sun gear forms a structural unit with the rotor carrier, preferably with the hub of the rotor carrier. By virtue of this variant the above-mentioned needle bearing between the bolt carrier and the rotor hub, as well as the neck of the sun gear with spline teeth, can be omitted.
In a further preferred embodiment, the gearwheels of the planetary gearset have helical teeth. This results in less noise and quieter running.
According to a further preferred embodiment the oil supply system of the planetary gearset and the electric machine is connected to the oil supply system of the main transmission. For that purpose an oil transfer port and longitudinal and transverse bores are provided in the transmission input shaft, by way of which the lubricating and cooling oil is fed in and drained away.
In a further preferred embodiment, oil is returned from the oil space of the hybrid housing to the oil space of the main transmission via an oil return pipe, which runs between the two transmission housings. This ensures the lubrication and cooling of the planetary gearset, the bearings and the electric machine.
In a further preferred embodiment the ring gear is connected to the hybrid housing by a ring gear carrier. Preferably, the ring gear carrier engages with outer teeth in the inner teeth of the ring gear.
According to a further preferred embodiment, the electric machine is designed as a permanently energized synchronous machine. For reasons to do with power density the permanently energized synchronous machine is designed for a relatively high rotational speed, which is adapted to the lower rotational speed of the transmission input shaft by virtue of the fixed transmission ratio of the planetary gearset. This gives the advantage that an electric machine with relatively low weight, compact fitting volume and relatively low cost can be used for the hybrid drive.
Example embodiments of the invention are illustrated in the drawing and will be described in more detail below, so that from the description and/or the drawing further features and/or advantages can emerge. The drawings show:
In the lower half of
1 Hybrid drive assembly
2 Main transmission
3 Hybrid module
4 Transmission input shaft
5 Electric machine
5
a Stator
5
b Rotor
6 Planetary gearset
7 Sun gear
8 Carrier (planetary carrier)
9 Ring gear
10 Clutch
11 Transmission output shaft
12 Oil pump
20 Hybrid housing
21 Rotor carrier
21
a Drum
21
b Hub
21
c Supporting disk
22 Fixed bearing
23 Hybrid module
24 Transmission input shaft
25 Electric machine
25
a Stator
25
b Rotor
26 Planetary gearset
27 Sun gear
27
a Neck
28 Carrier
28
a Neck
28
b Bolt carrier
29 Ring gear 29a Ring gear carrier
30 Planetary gearwheel
31 Planetary bolt
32 Fixed bearing
33 Needle bearing
34 Spline teeth
35 Pilot bearing (loose bearing)
36 Connection plate
37 Transmission housing
38 Oil transfer port
39 Transverse duct
40 Longitudinal duct
41 Transverse duct
42 Oil return
43 Rotor carrier
43
a Neck
44 Carrier
44
a Bolt carrier
45 Sun gear
R Reverse gear
Number | Date | Country | Kind |
---|---|---|---|
10 2013 211 225.4 | Jun 2013 | DE | national |
This application is a National Stage completion of PCT/EP2014/059600 filed May 12, 2014, which claims priority from German patent application serial no. 10 2013 211 225.4 filed Jun. 17, 2013.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2014/059600 | 5/12/2014 | WO | 00 |