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US 7,694,598 B2Granted
Two-speed transfer case with adaptive torque transfer clutch
AssigneeMAGNA Powertrain AG & Co KG
InventorsAugust Kriebernegg, Klaus Lippitsch
Life of this patent
Estimating the term…
Abstract
A transfer case includes a two-speed range unit, a friction clutch, a power-operated actuation mechanism and a control system. The actuation mechanism includes an electric motor, a geartrain driven by the motor for controlling rotation of an actuator shaft, a range actuator assembly and a mode actuator assembly. The range actuator assembly functions to move a shift collar associated with the range unit in response to rotation of the actuator shaft. The mode actuator assembly includes a mode cam and a ballramp unit. The mode cam is rotatively driven by the actuator shaft for controlling the clutch engagement force exerted on the friction clutch by the ballramp unit.
Claims17
A transfer case comprising:
- an input shaft;
- first and second output shafts;
- a range unit driven at a reduced speed relative to said input shaft;
- a range clutch operable in a first range position to establish a drive connection between said input shaft and said first output shaft and further operable in a second range position to establish a drive connection between said range unit and said first output shaft;
- a mode clutch operable in a first mode position to disengage said second output shaft from driven engagement with said first output shaft and further operable in a second mode position to establish a drive connection between said first output shaft and said second output shaft;
- a geartrain having an input gear driving an output gear;
- an electric motor driving said input gear;
- an actuator shaft driven by said output gear;
- a range actuator driven by said actuator shaft for moving said range clutch between its first and second range positions;
- a mode actuator driven by said actuator shaft for moving said mode clutch between its first and second mode positions, said mode actuator including a mode cam driven by said actuator shaft and a ball ramp unit having a first cam member, a second cam member disposed for rotation and axial movement relative to said first cam member, and rollers disposed in cam grooves formed between said first and second cam members, said first cam member having a first lever segment disposed on one side of said actuator shaft and said second cam member having a second lever segment disposed on an opposite side of said actuator shaft which includes a mode follower engaging a cam surface on said mode cam, said cam surface is configured to cause movement of said second cam member relative to said first cam member between a retracted position and an extended position in response to rotation of said mode cam with said actuator shaft for moving said mode clutch between its first and second mode positions;
- and
- a control system for actuating said motor to control the magnitude and direction of rotation of said actuator shaft so as to coordinate movement of said range clutch and said mode clutch.
9 more elements
A transfer case comprising:
- an input shaft;
- first and second output shafts;
- a range unit driven by said input shaft and having an output component driven at a reduced speed relative to said input shaft;
- a dog clutch operable in a first range position to couple said input shaft to said first output shaft for establishing a high-range drive connection, said dog clutch is further operable in a second range position to couple said output component of said range unit to said first output shaft for establishing a low-range drive connection;
- a mode clutch including a clutch pack operably disposed between said first and second output shafts and a pressure plate moveable between a first mode position whereat a minimum clutch engagement force is exerted on said clutch pack and a second mode position whereat a maximum clutch engagement force is exerted on said clutch pack;
- and
- an actuation mechanism including a geartrain having an input gear and an output gear, a motor driving said input gear, an actuator shaft driven by said output gear, a range actuator driven by said actuator shaft for moving said dog clutch between its first and second range positions, and a mode actuator driven by said actuator shaft for moving said pressure plate between its first and second mode positions, said mode actuator including a mode cam driven by said actuator shaft and a ball ramp unit having a first cam member, a second cam member disposed for rotation and axial movement relative to said first cam member, and rollers disposed in cam grooves formed between said first and second cam members, said first cam member having a first lever segment disposed on one side of said actuator shaft and said second cam member having a second lever segment disposed on an opposite side of said actuator shaft which includes a mode follower engaging a cam surface on said mode cam, said cam surface is configured to cause movement of said second cam member relative to said first cam member between a retracted position and an extended position in response to rotation of said mode cam with said actuator shaft for moving said pressure plate between its first and second mode positions, and wherein said actuator shaft being rotatable through three distinct ranges of rotary travel for causing said range actuator and said mode actuator to coordinate movement of said dog clutch and said pressure plate.
4 more elements
A transfer case, comprising:
- first and second shafts;
- a mode clutch operable in a first mode to disengage said second shaft from driven engagement with said first shaft and in a second mode to establish a drive connection between said first and second shafts;
- an actuator shaft;
- an electric motor operable for rotating said actuator shaft;
- and
- a mode actuator driven by said actuator shaft for shifting said mode clutch between its first and second modes, said mode actuator including a mode cam driven by said actuator shaft and a cam mechanism disposed between said mode cam and an axially moveable clutch component of said mode clutch, said cam mechanism including a first cam member having a first lever segment disposed on one side of said actuator shaft and a second cam member having a second lever segment disposed on an opposite side of said actuator shaft and supporting a follower engaging a cam surface on said mode cam, said cam surface is configured to cause relative rotation between said first and second cam members in response to rotation of said actuator shaft for moving said clutch component between first and second mode positions for shifting said mode clutch between its first and second modes.
3 more elements
Dependencies are inferred from the claim text.