Electric drive system with power take-off (PTO) and electric drive operating method
Systems and methods for an electric drive. The electric drive system includes, in one example, a first electric machine rotationally coupled to a first sun gear in a first planetary gear set and a second electric machine rotationally coupled to a second sun gear in a second planetary gear set. The electric drive system further includes a first clutch configured to selectively rotationally couple the second sun gear to a first ring gear in the first planetary gear set, a second clutch configured to ground a second ring gear in the second planetary gear set, and a power take-off (PTO) clutch configured to selectively rotationally couple the first electric machine or the first planetary gear set to a PTO device.
1 . An electric drive system, comprising:
a first electric machine rotationally coupled to a first sun gear in a first planetary gear set;
a second electric machine rotationally coupled to a second sun gear in a second planetary gear set;
a first clutch configured to selectively rotationally couple the second sun gear to a first ring gear in the first planetary gear set;
a second clutch configured to selectively ground a second ring gear in the second planetary gear set; and
a power take-off (PTO) clutch configured to selectively rotationally couple the first electric machine;
wherein a first carrier in the first planetary gear set is rotationally coupled to a first output interface that is coupled to a first axle differential; and
wherein a second carrier in the second planetary gear set is coupled to a second output interface that is coupled to a second axle differential.
2 . The electric drive system of claim 1 , further comprising a controller including instructions that when executed cause the electric drive system to:
operate the electric drive system in a lower-speed mode via engaging the first clutch and the second clutch.
3 . The electric drive system of claim 2 , wherein the controller includes instructions that when executed cause the electric drive system to:
engage the PTO clutch in response to vehicle speed surpassing a threshold value.
4 . An electric drive system, comprising:
a first electric machine rotationally coupled to a first sun gear in a first planetary gear set;
a second electric machine rotationally coupled to a second sun gear in a second planetary gear set;
a first clutch configured to selectively rotationally couple the second sun gear to a first ring gear in the first planetary gear set;
a second clutch configured to selectively ground a second ring gear in the second planetary gear set;
a power take-off (PTO) clutch configured to selectively rotationally couple the first electric machine;
wherein a first carrier in the first planetary gear set is rotationally coupled to a first output interface and a second carrier in the second planetary gear set is coupled to a second output interface; and
a controller including instructions that when executed cause the electric drive system to:
operate the electric drive system in a mid-speed mode via engaging the second clutch and disengaging the first clutch.
5 . The electric drive system of claim 4 , wherein the controller includes instructions that when executed cause the electric drive system to:
engage the PTO clutch; and
operate the first electric machine in a regeneration mode.
6 . An electric drive system, comprising:
a first electric machine rotationally coupled to a first sun gear in a first planetary gear set;
a second electric machine rotationally coupled to a second sun gear in a second planetary gear set;
a first clutch configured to selectively rotationally couple the second sun gear to a first ring gear in the first planetary gear set;
a second clutch configured to selectively ground a second ring gear in the second planetary gear set;
a power take-off (PTO) clutch configured to selectively rotationally couple the first electric machine;
wherein a first carrier in the first planetary gear set is rotationally coupled to a first output interface and a second carrier in the second planetary gear set is coupled to a second output interface; and
a controller including instructions that when executed cause the electric drive system to:
operate the electric drive system in a higher-speed mode via engaging the second clutch and disengaging the first clutch.