Liquid cooled fan clutch

Patent metadata

Field	Value
Publication number	US-10030717-B2
Application number	US-201514753391-A
Country	US
Kind code	B2
Filing date	Jun 29, 2015
Priority date	Jun 29, 2015
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

A liquid cooled viscous fan clutch transfers torque from a driving plate driven by an engine crankshaft to a driven plate connected to a cooling fan. Heat generated in a working fluid is transferred to a second fluid, such as engine coolant or transmission fluid, flowing through a cooling jacket. The cooling jacket is located in a stationary housing which may be fixed to the engine. The working fluid circulates through a working zone, a passageway in the stationary housing, and a passageway in the driving plate. Rotation of the driving plate provides the motive force to circulate the fluid, independent of the rotation speed of the driven plate. A controllable valve may be closed to block circulation, trapping working fluid in a reservoir, to disengage the clutch.

First claim

What is claimed is:

1. A viscous fan clutch comprising:
input and output shafts;
a drive plate fixed to the input shaft and having a first plurality of cylindrical ridges, the drive plate and input shaft defining a first fluid passageway from a first inlet port to a first outlet port located radially inside an innermost ridge of the first plurality of ridges;
a driven plate fixed to the output shaft and having a second plurality of cylindrical ridges interspersed with the first plurality of ridges such that viscous shear acting on a working fluid between the first and second pluralities of ridges exerts torque on the driven plate; and
a stationary housing defining a second fluid passageway from a second inlet port located radially outside the first outlet port to a second outlet port adjacent to the first inlet port such that rotation of the drive plate and driven plate relative to the housing propels the working fluid through the first passageway, between the first and second pluralities of ridges, and through the second passageway.

2. The viscous fan clutch of claim 1 wherein the stationary housing further defines a coolant jacket proximate to the second passageway to provide heat transfer from the working fluid to coolant in the coolant jacket.

3. The viscous clutch of claim 1 wherein the first passageway includes a fluid reservoir.

4. The viscous clutch of claim 3 further comprising a valve configured to selectively block the first passageway such that fluid is retained in the reservoir.

5. The viscous fan clutch of claim 4 further comprising an electro-magnetic actuator fixed to the stationary housing and configured to bias the valve in a first axial direction.

6. The viscous fan clutch of claim 5 further comprising a return spring configured to bias the valve in a second axial direction opposite the first axial direction.

7. The viscous fan clutch of claim 6 wherein the electro-magnetic actuator acts to open the valve to engage the clutch and the return spring acts to close the valve to disengage the clutch.

8. A clutch comprising:
a housing defining a passageway;
a driven plate supported within the housing for rotation relative to the housing;
a driving plate supported within the housing for rotation relative to the housing in proximity to the driven plate to define a working zone, the driving plate configured to circulate a working fluid through the working zone and the passageway; and
a valve configured to selectively block flow of the working fluid;
wherein the passageway runs from an inlet port radially outside the working zone, through the housing, across a gap between the housing and the driven plate, through the driven plate, to an outlet port radially inside the working zone.

9. The clutch of claim 8 wherein the housing further defines a coolant jacket such that heat is transferred from the working fluid to a coolant flowing through the coolant jacket.

10. The clutch of claim 8 wherein the passageway includes a fluid reservoir.

11. The clutch of claim 10 wherein the fluid reservoir is located within the drive plate.

12. The clutch of claim 10 wherein the valve is configured to selectively block the passageway such that fluid is retained in the reservoir.

13. The clutch of claim 12 further comprising an electro-magnetic actuator fixed to the housing and configured to bias the valve in a first direction.

14. The clutch of claim 13 further comprising a return spring configured to bias the valve in a second direction opposite the first direction.

15. The clutch of claim 14 wherein the electro-magnetic actuator acts to open the valve to engage the clutch and the return spring acts to close the valve to disengage the clutch.

16. A powertrain comprising:
an engine having a crankshaft and an accessory drive shaft driven by the crankshaft;
a cooling fan;
a viscous clutch configured to selectively transfer torque from the accessory drive shaft to the cooling fan, the viscous clutch having a housing fixed to the engine and defining a cooling jacket;
a transmission driven by the crankshaft; and
plumbing configured to route transmission fluid from the transmission through the viscous clutch.

17. The powertrain of claim 16 wherein the viscous clutch further comprises:
a driven plate driveably connected to the cooling fan and supported for rotation within the housing; and
a driving plate driveably connected to the crankshaft and supported for rotation within the housing in proximity to the driven plate to define a working zone, the driving plate configured to circulate a working fluid through the working zone and through a heat exchange interface with the transmission fluid.

18. The powertrain of claim 17 further comprising a valve configured to selectively block flow of the working fluid to disengage the clutch.

Assignees

• Ford Global Tech Llc

Inventors

• Mehravaran Meisam
• Bowlby Gregory

Classifications

• F16D2300/0214

  Oil or fluid cooling · CPC title

• F01P7/081

  using clutches, e.g. electro-magnetic or induction clutches · CPC title

• F16D35/024 Primary

  the valve being actuated electrically, e.g. by an electromagnet (F16D35/026 takes precedence) · CPC title

• F16D35/027

  actuated by emptying and filling with viscous fluid from outside the coupling during operation · CPC title

• F16D35/028 Primary

  actuated electrically, e.g. by an electromagnet (valves actuated electrically F16D35/024) · CPC title