Active transfer case with splash recovery clutch lubrication system

Patent metadata

Field	Value
Publication number	US-9568091-B2
Application number	US-201514718798-A
Country	US
Kind code	B2
Filing date	May 21, 2015
Priority date	May 21, 2015
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

An active transfer case is disclosed having a multi-plate friction clutch installed on the front output shaft. A splash recovery clutch 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 clutch 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 a flow channel communicating with said oil feed passage and a tubular segment surrounding said second shaft and defining an annular chamber communicating with said flow channel, and a flow control device operable to controllably regulate flow of said lubricant from said annular chamber into 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 a first inlet port configured to catch lubricant splashed upon rotation of said clutch drum and a second inlet port configured 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 3 wherein movement of said second cam ring causes movement of said flow control device so as to meter the amount of lubricant flowing from said annular chamber into said clutch feed chamber.

5. The transfer case of claim 4 wherein said splash recovery lubrication system further includes a flow restrictor ring disposed within said annular chamber and having at least one flow aperture, and wherein movement of said flow control device in response to movement of said second cam ring regulates flow of lubricant through said flow aperture.

6. The transfer case of claim 5 wherein said clutch flow control device includes a shroud segment and a radial flange segment, wherein said shroud segment surrounds said tubular segment of said oil conduit, wherein said radial flange segment overlies an end portion of said tubular segment of said oil conduit and encloses said annular chamber, and wherein radial movement of said clutch flow control device causes window apertures formed in said radial flange segment to align with said flow aperture so as to permit lubricant to flow from said annular chamber into said clutch feed chamber.

7. The transfer case of claim 6 wherein said splash recovery clutch lubrication system further includes a clutch feed cover having a funnel section surrounding said shroud segment of said clutch flow control device 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 flow control device so as to define said clutch feed chamber therebetween.

8. The transfer case of claim 7 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.

9. The transfer case of claim 8 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.

10. The transfer case of claim 1 further comprising a two-speed range mechanism disposed between an input shaft driven by the powertrain and said first shaft and which is operable to establish first and second speed ratio driving connections therebetween.

11. 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.

12. 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.

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-op

Assignees

• Magna Powertrain America Inc

Inventors

• Drill Daniel M
• Reth Borin

Classifications

• F16D13/74

  Features relating to lubrication · CPC title

• F16D13/76

  specially adapted to incorporate with other transmission parts, i.e. at least one of the clutch parts also having another function, e.g. being the disc of a pulley · CPC title

• F16D13/52

  Clutches with multiple lamellae {; Clutches in which three or more axially moveable members are fixed alternately to the shafts to be coupled and are pressed from one side towards an axially-located member (F16D13/385 takes precedence)} · CPC title

• F16H57/0483

  Axle or inter-axle differentials · CPC title

• F16H57/0473

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