Multi-speed electric drive axle using multi-layshaft transmission
An electric drive axle with an electric motor having a motor shaft that is rotatable about an axis, a differential, and a transmission. The transmission transmits rotary power between the motor shaft and the differential. The multi-speed reduction has an input shaft and at least three on-axis gears. The input shaft is rotatably coupled to the motor shaft. Each of the at least three on-axis gears is co-axial with the input shaft and is rotatable relative to the input shaft in at least one of a first speed ratio and a second speed ratio. The input shaft is axially movable along the axis between a first position, in which a first one of the at least three on-axis gears is rotationally coupled to the input shaft, and a second position in which a second one of the at least three on-axis gears is rotationally coupled to the input shaft.
1 . An electric drive axle comprising:
a housing assembly having first and second housing members that cooperate to define a transmission cavity therebetween;
a transmission received in the transmission cavity, the transmission having a gear that is supported by a bearing, the bearing being received in a bearing mount; and
a park-lock mechanism that includes:
a park-lock gear coupled for rotation with an element of the transmission;
a pivot pin received in the second housing member and being rotatable relative to the second housing member about a pivot axis;
a park pawl coupled to the pivot pin for common rotation the pivot axis between an engaged position, in which the park pawl is engaged to the park-lock gear, and a disengaged position in which the park pawl is disengaged from the park-lock gear;
a spring biasing the park pawl out of engagement with the park-lock gear; and
a park-lock plunger assembly having an input member, a plunger, and a compliance spring, the input member being disposed along an actuation axis, the plunger being slidably disposed on the input member and movable along the actuation axis between a first position and a second position, the actuation axis being parallel to the pivot axis, wherein movement of the plunger from the first position toward the second position causes corresponding motion of the park pawl toward the engaged position, and wherein placement of the plunger in the second position permits the spring to move the park pawl into the disengaged position, the compliance spring is disposed coaxially on the input member and biasing a head of the input member apart from the plunger;
wherein the park-lock mechanism further includes a park-lock actuator coupled to the second housing member and being selectively operable for translating the input member along the actuation axis; and
wherein the park-lock actuator includes a lever that is pivotable about a lever axis that is perpendicular to the actuation axis, the lever being coupled to the input member such that pivoting movement of the lever causes corresponding translation of the input member; and
wherein the park-lock actuator further includes a park-lock motor having a motor output member that is rotatable about a motor axis, which is different from and parallel to the lever axis, and the motor output member is coupled to the lever such that rotation of the motor output member about the motor axis causes corresponding rotation of the lever about the lever axis; and an intermediate lever is rotatable integrally with the park-lock motor.
2 . The electric drive axle of claim 1 , wherein the park-lock actuator further includes a lock mechanism having a latch that is engagable to the lever to inhibit pivoting motion of the lever about the lever axis.
3 . The electric drive axle of claim 2 , wherein the park-lock mechanism further comprises a guide structure that is mounted to the second housing member, the guide structure being configured to guide the plunger for movement between the first and second positions.
4 . The electric drive axle of claim 3 , wherein the lock mechanism is mounted to the guide structure.
5 . The electric drive axle of claim 1 , wherein the park-lock actuator further includes a manual input lever that is coupled to the lever for rotation therewith about the lever axis.