US 6,905,436 B2Granted

Two-speed transfer case with adaptive clutch control

AssigneeMagna Drivetrain of America, Inc.

InventorsJoseph G. Mueller, Gareth Thomas

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Abstract

A transfer case having an input shaft driven by a powertrain, a first output shaft adapted for connection to a first driveline, a second output shaft adapted for connection to a second driveline, an interaxle differential operably disposed between the input shaft and the first and second output shafts, and a torque transfer mechanism. The torque transfer mechanism includes a friction clutch assembly operably disposed between the first output shaft and the second output shaft, and a clutch actuator assembly for generating and applying a clutch engagement force to the friction clutch assembly. The clutch actuator assembly includes an electric motor, a geared reduction unit, and a clutch apply operator. A control system including vehicle sensors and a controller are provided to control actuation of the electric motor.

Claims32

Dependent claims

A power transfer assembly for use in a motor vehicle to transfer drive torque from a powertrain to first and second drivelines, comprising:

an input shaft adapted to be driven by the powertrain;
a first output shaft adapted for connection to the first driveline;
a second output shaft adapted for connection to the second driveline;
a reduction unit having an input member driven by said input shaft and an output member driving said first output shaft;
a range clutch operable in a first range position to couple said input member to said first output shaft for establishing a high-range drive connection therebetween, said range clutch is operable in a second range position to couple said output member to said first output shaft for establishing a low-range drive connection therebetween, and said range clutch is operable in a third position to release said first output shaft from engagement with said input member and said output member;
a range shift mechanism for moving said range clutch between its range positions in response to rotation of a driveshaft;
a torque transfer mechanism for transferring drive torque from said first output shaft to said second output shaft, said torque transfer mechanism including a friction clutch operably disposed between said first and second output shafts and a clutch actuator assembly for applying a clutch engagement force on said friction clutch, said clutch actuator assembly including an electric motor driving said driveshaft, a gearset driven by said driveshaft, and a clutch apply operator having a first member driven by said gearset, a second member axially moveable between first and second mode positions for controlling the magnitude of said clutch engagement force exerted on said friction clutch, and a third member for converting rotary movement of said first member into axial movement of said second member, said third member including means for coordinating movement of said second member between its mode positions with movement of said range clutch between its range positions in response to rotation of said driveshaft;
and
a control system for controlling actuation of said electric motor.

6 more elements

A transfer case for use in a four-wheel drive vehicle having a powertrain and first and second drivelines, comprising:

an input shaft driven by the powertrain;
a first output shaft connected to the first driveline;
a second output shaft connected to the second driveline;
a reduction unit having an input member driven by said input shaft and an output member drivingly connected to said first output shaft;
an axially moveable range sleeve operable in a neutral range position to disconnect said first output shaft from driven connection with said input shaft, in a high-range position to connect said first output shaft for common rotation with said input shaft, and in a low-range position to connect said first output shaft for rotation with said output member of said reduction unit;
a friction clutch operably disposed between said first output shaft and said second output shaft;
an electric motor for selectively driving a driveshaft;
a range shift mechanism for moving said range sleeve between its three distinct range positions in response to rotation of said driveshaft;
a clutch actuator assembly including a rotary drive member with rollers, and a non-rotary cam member having a tapered ramp surface in engagement with said rollers, said cam member being axially moveable relative to said friction clutch between a retracted position whereat said friction clutch is released and an extended position whereat said friction clutch is engaged in response to rotation of said drive member;
a movement coordinating mechanism including a drive gear fixed to said driveshaft and a rotary sector member having a gear segment meshed with said drive gear, said sector member having an arcuate slot and said drive member includes a follower pin extending into said slot, said slot permitting bidirectional rotation of said driveshaft for moving said range sleeve between its three distinct range positions while said sector member rotates relative to said drive member to maintain said cam member in its retracted position;
a mode selector for permitting selection of different drive modes and generating a mode signal indicative of the drive mode selected;
a sensor for sensing an operational characteristic of the vehicle and generating a sensor signal;
and
a controller receiving said mode signal and said sensor signals and controlling actuation of said electric motor in response thereto.

11 more elements

A power transfer assembly for use in a full-time four-wheel drive vehicle having a powertrain and first and second drivelines, comprising:

an input shaft driven by the powertrain;
a first output shaft driving the first driveline;
a second output shaft driving the second driveline;
a reduction unit having an input member driven by said input shaft and an output member;
an interaxle differential having an input driven by said output member of said reduction unit and first and second outputs respectively connected to said first and second output shafts;
a range clutch operable in a first range position to establish a high-range drive connection between said input shaft and said input of said interaxle differential, said range clutch is operable in a second range position to establish a low-range drive connection between said input shaft and said input of said interaxle differential, and said range clutch is operable in a third position to release said input of said interaxle differential from drive connection with said input shaft;
a range shift mechanism for moving said range clutch between its range positions in response to rotation of a driveshaft;
a torque transfer mechanism for transferring drive torque from said first output shaft to said second output shaft, said torque transfer mechanism including a friction clutch operably disposed between said first and second output shafts and a clutch actuator assembly for applying a clutch engagement force to said friction clutch, said clutch actuator assembly including an electric motor driving said driveshaft, a gearset driven by said driveshaft, and a clutch apply operator having a first member driven by said gearset, a second member axially moveable between a first and second mode position for controlling the magnitude of said clutch engagement force exerted on said friction clutch, and a third member for converting rotary movement of said first member into axial movement of said second member, said third member including means for coordinating movement of said second member between its mode positions with movement of said range clutch between its range positions in response to rotation of said driveshaft;
and
a control system for controlling actuation of said electric motor.

7 more elements

A transfer case for use in a four-wheel drive vehicle having a powertrain and first and second drivelines, comprising:

an input shaft driven by the powertrain;
a first output shaft driving the first driveline;
a second output shaft driving the second driveline;
a reduction unit having an input member driven by said input shaft and an output member;
a differential having an input driven by said output member of said reduction unit, a first output driving said first output shaft, and a second output driving said second output shaft;
an axially moveable range sleeve operable in a neutral range position to disconnect said differential input from driven connection with said input shaft, in a high-range position to establish a first speed ratio driven connection between said differential input and said input shaft, and in a low-range position to establish a second speed ratio drive connection between said differential input and said input shaft;
a friction clutch operably disposed between said first output shaft and said second output shaft;
an electric motor for selectively driving a driveshaft;
a range shift mechanism for moving said range sleeve between its range positions in response to rotation of said driveshaft;
a clutch actuator assembly including a rotary drive member having rollers, and a non-rotary cam member having a tapered ramp surface in engagement with said rollers, said cam member being axially moveable relative to said friction clutch between a retracted position whereat said friction clutch is released and an extended position whereat said friction clutch is engaged in response to rotation of said drive member;
a movement coordinating mechanism including a drive gear fixed to said driveshaft and a rotary sector member having a gear segment meshed with said drive gear, said sector member having a slot and said drive member includes a follower pin extending into said slot, said slot permitting bi-directional rotation of said driveshaft for moving said range sleeve between its range positions while said sector member rotates relative to said drive member and maintains said cam member in its retracted position;
a mode selector for permitting selection of different four-wheel drive modes and generating a mode signal indicative of the drive mode selected;
a sensor for sensing an operational characteristic of the vehicle and generating sensor signal;
and
a controller receiving said mode signal and said sensor signal and controlling actuation of said electric motor in response thereto.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/696,944Filed 30 Oct 2003
Published: US 2005/0096172 A15 May 2005
Granted: 14 Jun 2005
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

B60K 17/3467
The transfer gear being a differential gear: combined with a change speed gearing, e.g. range gear
B60K 23/0808
For changing number of driven wheels , for switching from driving one axle to driving two or more axles: for varying torque distribution between…
F16D 23/12
Details of mechanically-actuated clutches not specific for one distinct type: mechanical clutch-actuating mechanisms arranged outside the clutch…
F16D 23/14
Mechanical clutch-actuating mechanisms arranged outside the clutch as such: clutch-actuating sleeves or bearings; Actuating members directly…