Active transfer case with splash recovery clutch lubrication system

Patent metadata

Field	Value
Publication number	US-10330189-B2
Application number	US-201715431910-A
Country	US
Kind code	B2
Filing date	Feb 14, 2017
Priority date	May 21, 2015
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

An active transfer case is disclosed having a multi-plate friction clutch installed on the front output shaft. A splash recovery lubrication system is provided to capture lubricant splashed from the sump in response to rotation of the friction clutch and transfer the captured lubricant to a central clutch feed chamber to cool and lubricate the components of the friction clutch.

First claim

The invention claimed is:

1. A transfer case for use in a four-wheel drive motor vehicle having a powertrain and first and second drivelines, the transfer case comprising:
a housing defining a sump area filled with a lubricant;
a first shaft rotatably supported by said housing and configured to transfer drive torque from the powertrain to the first driveline;
a second shaft rotatably supported by said housing in close proximity to said sump area and configured for connection to the second driveline;
a transfer mechanism having a first transfer component drivingly coupled to said first shaft and a second transfer component driven by said first transfer component, said second transfer component being rotatably mounted on said second shaft;
a multi-plate friction clutch assembly surrounding said second shaft and including a first clutch member drivingly coupled to said second transfer component, a second clutch member drivingly coupled to said second shaft, and a clutch pack of interleaved first and second clutch plates drivingly coupled to corresponding one of said first and second clutch members;
a power-operated clutch actuator operable for moving an apply member relative to said clutch pack so as to control the magnitude of a clutch engagement force exerted thereon and concurrently control the amount of drive torque transferred from said first shaft through said transfer mechanism and said friction clutch assembly to said second shaft; and
a splash recovery lubrication system for capturing lubricant splashed in response to rotation of at least one of said second transfer component and said first clutch member and feeding said captured lubricant to a clutch feed chamber that is in fluid communication with said clutch pack, said splash recovery clutch lubrication system including an oil catcher reservoir configured to capture splashed lubricant and retain said captured lubricant in an oil catcher cavity, an oil feed reservoir having an oil feed cavity communicating with said oil catcher cavity and an oil feed passage, an oil conduit having a web segment with first and second flow channels communicating with said oil feed passage and a tubular segment surrounding said second shaft and defining an annular clutch feed chamber, said first flow channel communicating with said clutch feed chamber for directing lubricant to said multi-plate function clutch assembly, and said second flow channel not communicating with said clutch feed chamber.

2. The transfer case of claim 1 wherein said transfer mechanism includes a first sprocket drivingly coupled to said first shaft, a second sprocket rotatably supported on said second shaft, and a power chain encircling said first and second sprockets for transferring drive torque from said first shaft to said second sprocket, wherein said first clutch member is a clutch drum fixed for rotation with said second sprocket and said second clutch member is a clutch hub fixed for rotation with said second shaft, and wherein said oil catcher reservoir includes at least one inlet port configured to catch lubricant splashed upon rotation of said clutch drum or to catch lubricant splashed upon rotation of said power chain and/or said second sprocket.

3. The transfer case of claim 1 wherein said power-operated clutch actuator includes a ballramp unit having a first cam ring and a second cam ring that is axially moveable relative to said first cam ring, wherein said web segment of said oil conduit is connected to said first cam ring, and wherein said tubular segment of said oil conduit is disposed between said second shaft and said second cam ring.

4. The transfer case of claim 1 wherein said tubular segment of said oil conduit includes an outer shroud and an inner cylindrical lip, wherein said inner cylindrical lip surrounds said second shaft, and wherein said shroud surrounds said inner cylindrical lip of said oil conduit.

5. The transfer case of claim 4 wherein said splash recovery lubrication system further includes a clutch feed cover having a funnel section surrounding said shroud of said oil conduit and a radial plate segment, and a clutch feed device drivingly coupled for rotation with said second shaft, wherein said clutch feed device includes a ring segment fixed to said plate segment of said clutch feed cover so as to define said clutch feed chamber therebetween.

6. The transfer case of claim 5 wherein said clutch feed device further includes a plurality of tubular conduits extending axially from said ring segment and retained in apertures formed in said second clutch plates, said conduits each having radial discharge ports for transmitting lubricant from said clutch feed chamber radially outwardly into said clutch pack.

7. The transfer case of claim 6 wherein said clutch feed device further includes drive lugs extending from said ring segment and which are coupled for common rotation with said second shaft.

8. The transfer case of claim 1 wherein said oil catcher reservoir and said oil feed reservoir are interconnected and fixed to said housing, and wherein lubricant in said oil catcher cavity is gravity fed to said oil feed cavity.

9. The transfer case of claim 1 wherein said oil catcher reservoir is disposed above said friction clutch assembly, wherein said oil feed reservoir is disposed above said clutch actuator, and wherein said clutch assembly is at least partially disposed for rotation within said sump of lubricant.

10. The transfer case of claim 4 wherein said outer shroud of said oil conduit includes lubricant discharge ports for directing lubricant within said clutch feed chamber to rotary components surrounding said tubular web segment.

11. The transfer case of claim 1 wherein said second shaft is rotatably supported in said housing by a first bearing assembly located forward of said multi-plate friction clutch assembly and a second bearing assembly located rearward of said power-operated clutch actuator, and wherein said second flow channel in said web segment of said oil conduit directs lubricant to said second bearing assembly.

12. The transfer case of claim 1 wherein said first flow channel directs lubricant in a first direction towards said clutch assembly, and wherein said second flow channel directs lubricant in a second direction opposite to said first direction.

13. A transfer case for use in a four-wheel drive motor vehicle having a powertrain and first and second drivelines, the transfer case comprising:
a housing defining a sump area filled with a lubricant;
a first shaft rotatably supported by said housing and configured to transfer drive torque from the powertrain to the first driveline;
a second shaft rotatably supported by said housing in close proximity to said sump area and configured for connection to the second driveline;
a transfer mechanism having a first transfer component drivingly coupled to said first shaft and a second transfer component driven by said first transfer component, said second transfer component being rotatably mounted on said second shaft;
a multi-plate friction clutch assembly surrounding said second shaft and including a first clutch member drivingly coupled to said second transfer component, a second clutch member drivingly coupled to said second shaft, and a clutch pack of interleaved first and second clutch plates drivingly coupled to corresponding one of said first and second clutch members;
a power-operated clutch actuator operable for moving an apply member relative to said clutch pack so as to control the magnitude of a clutch engagement force exerted thereon and concurrently control the amount of drive torque transferred from said first shaft through said transf

Assignees

• Magna Powertrain America Inc

Inventors

• Drill Daniel M
• Reth Borin
• Martinez Frausto Julio Cesar

Classifications

• F16H57/0409 Primary

  characterised by increasing efficiency, e.g. by reducing splash losses · CPC title

• F16H57/0457

  Splash lubrication · CPC title

• F16H57/05

  of chains · CPC title

• F16H57/0473

  Friction devices, e.g. clutches or brakes · CPC title

• B60K17/344

  having a transfer gear · CPC title