Patent ID: 7540820
Filing Date: 2009-06-02
Classification: B60K,F16H

Abstract:
1. A transfer case comprising: an input shaft; first and second output shafts; an interaxle differential having an input member, a first output member coupled to said first output shaft, a second output member coupled to said second output shaft, and a gearset interconnecting said input member to said first and second output members; 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 moveable between a first range position and a second range position, said dog clutch is operable in its first range position to releasably couple said input shaft to said input member of said differential for establishing a high-range drive connection therebetween, and said dog clutch is operable in its second range position to releasably couple said output component of said range unit to said input member of said differential for establishing a low-range drive connection therebetween, a friction clutch operably disposed between said any two members of said interaxle differential; a ballramp unit having a first plate, a second plate and rollers engaging a cam surface formed between said first and second plates, said first plate is adapted to move axially relative to said friction clutch in response to rotary movement of said second plate between a first mode position whereat a minimum clutch engagement force is exerted on said friction clutch and a second mode position for whereat a maximum clutch engagement force is exerted on said friction clutch; and a power-operated actuation mechanism for controlling coordinated movement of said dog clutch between its first and second range positions and said second plate between its first and second mode positions, said actuation mechanism including a motor, a driveshaft rotatively driven by said motor, a mode cam assembly operably connecting said second plate to said driveshaft, a range cam driven by said driveshaft and a shift fork having a first segment engaging said range cam and a second segment coupled to said dog clutch, said mode cam assembly including a mode cam driven by said driveshaft and a sector plate coupled to said second plate, said mode cam having first and second followers and said sector plate having a first cam surface engageable with said first follower and a second cam surface engageable with said second follower.