Electric drive axle with lubrication system
Methods and systems for an electric drive axle of a vehicle are provided. An electric drive axle system includes, in one example a gear train configured to rotationally attach to an electric motor-generator, the gear train includes an output shaft having a clutch arranged thereon and configured to selectively rotationally couple a gear to the output shaft. The gear train further includes a lubrication channel extending between an output shaft and an axle shaft and including an outlet extending through the output shaft and opening into the clutch.
1. An electric drive axle system, comprising:
a gear train configured to rotationally attach to an electric motor-generator, the gear train comprising:
a first shaft having a first clutch arranged thereon and configured to selectively rotationally couple a first gear to the first shaft;
where the first shaft is parallel to and spaced away from a second shaft, and where the second shaft is directly coupled to a rotor shaft of the electric motor-generator and positioned coaxial to the rotor shaft;
where the first gear is configured to receive torque from the electric motor-generator;
where the first shaft is rotationally coupled to a gear assembly, the gear assembly is rotationally coupled to a differential, and the differential is rotationally coupled to an axle shaft that is arranged co-axial with the first shaft and designed to couple to a drive wheel, and where a rotational axis of the differential is parallel to and spaced away from a rotational axis of the electric motor-generator; and
a lubrication channel extending between the first shaft and the axle shaft and including a first outlet extending through the first shaft and opening into the first clutch;
where the lubrication channel extends axially along the axle shaft and is axially offset from a lateral side of the electric motor-generator;
where the first shaft is an output shaft and the lubrication channel includes a second outlet extending through the output shaft adjacent to a second clutch; and
where the second clutch is a one-way clutch.
2. The electric drive axle system of claim 1 , where the lubrication channel circumferentially surrounds an outer surface of an axle and where the first shaft is an output shaft and the second shaft is an input shaft.
3. The electric drive axle system of claim 1 , where the first gear includes a tapered inner surface configured to outflow a lubricant from the first clutch and where the first gear is coupled to a section of a clutch drum radially outward from a plurality of friction plates.
4. The electric drive axle system of claim 3 , where the lubrication channel extends through a disk carrier in the first clutch, and where the disk carrier is directly coupled to the first shaft.
5. The electric drive axle system of claim 4 , where the disk carrier is positioned axially between two bearings that are directly coupled to the first shaft.
6. The electric drive axle system of claim 1 , where the second outlet extending through the output shaft adjacent to the second clutch is adjacent to a roller bearing coupled to a second gear on the output shaft.
7. The electric drive axle system of claim 1 , where the electric drive axle system is a beam axle system that is structurally continuous and laterally spans a pair of drive wheels.
8. The electric drive axle system of claim 7 , where the gear assembly is a planetary gear assembly is directly coupled to the differential without any intervening components positioned therebetween.
9. An electric drive axle system, comprising:
a gear train including an input shaft that is directly rotationally attached to a rotor shaft of an electric motor-generator, the gear train comprising:
an output shaft having a wet friction clutch arranged thereon and configured to selectively rotationally couple a gear to the output shaft;
where the output shaft is parallel to and spaced away from a rotational axis of the electric motor-generator;
where the gear is coupled to an intermediate shaft that is parallel to the output shaft and the rotational axis of the electric motor-generator;
where the gear is configured to receive torque from the electric motor-generator;
where the output shaft is rotationally coupled to a planetary gear assembly, the planetary gear assembly is directly rotationally coupled to a differential, and the differential is coupled to a beam axle arranged co-axial with the output shaft; and
a lubrication conduit extending between the output shaft and an axle shaft of the beam axle and including a first outlet opening into a plurality of friction plates in the wet friction clutch;
where a portion of the lubrication conduit extends axially along the axle shaft and the output shaft at location between a drive wheel and the differential and axially offset from a lateral side of the electric motor-generator;
where the beam axle is structurally continuous and laterally spans a pair of drive wheels that includes the drive wheel; and
where the gear is coupled to a section of a clutch drum radially outward from the plurality of friction plates and where the gear includes a tapered inner surface configured to outflow a lubricant from the wet friction clutch.
10. The electric drive axle system of claim 9 , where the first outlet of the lubrication conduit extends radially through a friction disk carrier positioned radially inward from the plurality of friction plates in the wet friction clutch.
11. The electric drive axle system of claim 9 , where the lubrication conduit includes a second outlet extending through the output shaft adjacent to a one-way clutch.
12. The electric drive axle system of claim 9 , where the planetary gear assembly is directly coupled to the differential without any intervening components positioned therebetween.
13. The electric drive axle system of claim 12 , where the differential is a locking differential configured to rotationally lock and unlock axle shaft sections.