Claims
- 1. A transfer case comprising:
an input shaft; a reduction unit driven by said input shaft and having an output member rotatably driven at a reduced speed relative to said input shaft; an output shaft; a range clutch moveable between a high-range position and a low-range position, said range clutch is operable in its high-range position to couple said output shaft for common rotation with said input shaft and is operable in its low-range position to couple said output shaft for common rotation with said output member of said reduction unit; a power-operated shift actuator for moving said range clutch between at least three shift intervals defined between its high-range and low-range positions, said shift actuator is operable to move said range clutch through said first shift interval at a first velocity, through said second interval at a second interval, and through said third interval at a third velocity; and a controller for controlling actuation of said shift actuator.
- 2. The transfer case of claim 1 wherein said first and third velocities are greater than said second velocity.
- 3. The transfer case of claim 1 wherein said first shift interval extends from said high-range position, wherein said third shift interval extends from said low-range position, and wherein said second shift interval is located between said first and third shift intervals.
- 4. The transfer case of claim 3 further comprising a synchronizer assembly operably disposed between said range clutch and output member of said reduction unit, said synchronizer assembly operable to synchronize the rotary speed of said output shaft relative to said output member in response to movement of said range clutch through said second shift interval in a direction toward said low-range position.
- 5. The transfer case of claim 4 further comprising a second synchronizer assembly operably disposed between said range clutch and said output shaft, said second synchronizer assembly operable to synchronize the rotary speed of said output shaft relative to said input shaft in response to movement of said range clutch through said second shift interval in a direction toward said high-range position.
- 6. The transfer case of claim 1 wherein the length of said first shift interval is greater than the length of said second and third shift intervals.
- 7. The transfer case of claim 1 wherein said range clutch is a range sleeve having clutch teeth engageable with clutch teeth on a first component driven by said input shaft when said range sleeve is in its high-range position, wherein said clutch teeth on said range sleeve engage clutch teeth on a second component driven by said output member when said range sleeve is in its low-range position, and wherein said shift actuator includes an electric motor having a rotary output member and a shift mechanism operable for axially translating said range sleeve in response to rotation of said rotary output member of said motor, said controller operable for sending electric control signals to said electric motor for controlling the amount and direction of rotation of said motor output member.
- 8. A transfer case comprising:
an input shaft; a reduction unit driven by said input shaft and having an output member rotatably driven at a reduced speed relative to said input shaft; first and second output shafts; an interaxle differential having an input member and a gearset for driving said first and second output shafts; a range clutch moveable between a high-range position and a low-range position, said range clutch is operable in its high-range position to couple said input member for common rotation with said input shaft and is operable in its low-range position to couple said input member for common rotation with said output member of said reduction unit; a power-operated shift actuator for moving said range clutch between at least three shift intervals defined between its high-range and low-range positions, said shift actuator is operable to move said range clutch through said first shift interval at a first velocity, through said second interval at a second interval, and through said third interval at a third velocity; and a controller for controlling actuation of said shift actuator.
- 9. The transfer case of claim 8 wherein said first and third velocities are greater than said second velocity.
- 10. The transfer case of claim 8 wherein said first shift interval extends from said high-range position, wherein said third shift interval extends from said low-range position, and wherein said second shift interval is located between said first and third shift intervals.
- 11. The transfer case of claim 8 wherein the length of said first shift interval is greater than the length of said second and third shift intervals.
- 12. The transfer case of claim 8 wherein said range clutch is a range sleeve having clutch teeth engageable with clutch teeth on a first component driven by said input shaft when said range sleeve is in its high-range position, wherein said clutch teeth on said range sleeve engage clutch teeth on a second component driven by said output member when said range sleeve is in its low-range position, and wherein said shift actuator includes an electric motor having a rotary drive member and a shift mechanism operable for axially translating said range sleeve in response to rotation of said rotary drive member of said motor, said controller operable for sending electric control signals to said electric motor for controlling the amount and direction of rotation of said motor drive member.
- 13. A synchronized range shift apparatus for a two-speed gear system comprising:
a first rotary member driven at a first speed; a second rotary member driven at a second speed; a third rotary member; a clutch sleeve axially moveable from a first position through a first shift interval, a second shift interval, and a third shift interval to a second position, said clutch sleeve operable in its first position to couple said first rotary member to said third rotary member and in its second position to couple said second rotary member to said third rotary member; a synchronizer assembly disposed between said second rotary member and said clutch sleeve and operable to engage and substantially synchronize rotation of said third rotary member with said second rotary member when said clutch sleeve is displaced through its second shift interval; and an actuator operable to axially displace said clutch sleeve at a first velocity through said first interval, at a second velocity through said second shift interval, and at a third velocity through said third shift interval, wherein said first and third velocities are greater than said second velocity.
- 14. The apparatus of claim 13 wherein said first shift interval extends between said first position and a position adjacent a first side of said synchronizing assembly.
- 15. The apparatus of claim 14 wherein said second shift interval extends between said position adjacent said first side of said synchronizing assembly and a position adjacent a second side of said synchronizing assembly.
- 16. The apparatus of claim 15 wherein said third shift interval extends between said position adjacent to said second side of said synchronizing assembly and said second position.
- 17. The apparatus of claim 13 wherein said actuator includes a controller and a motor operable to axially displace said clutch sleeve.
- 18. The apparatus of claim 13 wherein said actuator is further operable to decelerate said clutch sleeve to a fourth velocity upon reaching said second position within said third interval, said fourth velocity less than said third velocity.
- 19. The apparatus of claim 18 wherein said actuator is further operable to accelerate said clutch sleeve to said first velocity and decelerate said clutch sleeve to said second velocity within said first interval and to accelerate said clutch sleeve to said third velocity and decelerate said clutch sleeve to said fourth velocity within said third interval.
- 20. A transfer case comprising:
an input shaft; a reduction unit driven by said input shaft and having an output member rotatably driven at a reduced speed relative to said input shaft; an output shaft; a range clutch moveable between a high-range position and a low-range position, said range clutch is operable in its high-range position to couple said output shaft for common rotation with said input shaft and is operable in its low-range position to couple said output shaft for common rotation with said output member of said reduction unit; a shift mechanism for moving said range clutch between at least three shift intervals defined between its high-range and low-range positions, said shift mechanism is operable to move said range clutch through said first shift interval at a first velocity, through said second interval at a second interval, and through said third interval at a third velocity; said shift mechanism includes a range fork engaging said range clutch, an electric motor having a rotary drive member, and a conversion unit for converting rotary motion of said drive member into translational motion of said range fork; and a control system for controlling actuation of said electric motor.
- 21. The transfer case of claim 20 wherein said first and third velocities are greater than said second velocity.
- 22. The transfer case of claim 20 wherein said first shift interval extends from said high-range position, wherein said third shift interval extends from said low-range position, and wherein said second shift interval is located between said first and third shift intervals.
- 23. The transfer case of claim 20 wherein the length of said first shift interval is greater than the length of said second and third shift intervals.
- 24. The transfer case of claim 20 wherein said range clutch is a range sleeve having clutch teeth engageable with clutch teeth on a first component driven by said input shaft when said range sleeve is in its high-range position, wherein said clutch teeth on said range sleeve engage clutch teeth on a second component driven by said output member when said range sleeve is in its low-range position, and wherein said controller is operable for sending electric control signals to said electric motor for controlling the amount and direction of rotation of said motor drive member to cause corresponding axial movement of said range sleeve.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/104,437 filed on Mar. 22, 2002.
Continuations (1)
|
Number |
Date |
Country |
Parent |
10104437 |
Mar 2002 |
US |
Child |
10732502 |
Dec 2003 |
US |