Cooling fin arrangement

• US 6,736,195 B2
• Filed: 06/15/2001
• Issued: 05/18/2004
• Est. Priority Date: 06/15/2000
• Status: Active Grant

• Current Assignee: BorgWarner Incorporated
• Original Assignee: BorgWarner Incorporated
• Inventors: Busch, Matthias, Tilly, Christian M., Tauschel, Thomas
• Primary Examiner(s): FLANIGAN, ALLEN J
• Application Number:
  US09/882,775
• Publication Number:
  US 20010052410A1
• Time in Patent Office: 1,068 Days
• Field of Search: 165/109.1, 165/185, 165/86
• US Class Current: 165/109.1
• CPC Class Codes: F01P 1/02 Arrangements for cooling cylinders or cylinder heads, e.g. ducting cooling-air from its pressure source to cylinders or along cylinders
• CPC Class Codes: F01P 7/042 using fluid couplings couplings or clutches of this type per se F16D35/00
• CPC Class Codes: F28F 13/12 by creating turbulence, e.g. by stirring, by increasing the force of circulation F28F13/08 takes precedence
• CPC Class Codes: F28F 3/02 Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations F28F3/08 takes precedence

Abstract

A containment (5) for a heat producing device has cooling fins (15) to dissipate the produced heat. In this type of cooling fin arrangement the cooling fins comprise, traditionally, smooth outer surfaces (17) so that in a boundary layer (18) the flow pattern of the cooling fluid along the cooling fins is laminar.

The present invention provides means (20) to break this laminar flow pattern in the boundary layer and herewith improves the heat transfer from the cooling fins to the cooling liquid.

This invention can advantageously be applied to viscous fan clutch covers.

Claims

1. An automotive clutch provided with a cooling fin arrangement, the clutch comprising a surface exposed to a cooling fluid, the surface in heat conductive relation with a viscous fluid between at least two clutch elements, a plurality of cooling fins defining fluid channels for the flow of the cooling fluid between the fins effective to transfer heat from the viscous fluid to the cooling fluid, and

protuberances on the surfaces of the cooling fins extending a distance into the cooling fluid flow effective to induce non-laminar flow therein, the protuberances having at least one edge oriented substantially perpendicular to the flow of the cooling fluid whereby a surface of said protuberances which is exposed to said fluid flow is arranged in angular relationship to said fluid flow, the non-laminar flow effective to increase the transfer of heat from the viscous fluid relative to the transfer of heat from the viscous fluid by a laminar flow through the channels.

2. The arrangement of claim 1, wherein said protuberances are formed integrally with the cooling fins.

3. The arrangement of claim 1, wherein said protuberances are formed by wires fastened to the surfaces of the cooling finds, the wires extending substantially perpendicular to the fluid flow.

4. The arrangement of claim 1, wherein the relative height of elevation of said protuberances from a general surface of said cooling fin is selected to assure that the fluid flow pattern of the cooling fluid through said cooling fins is turbulent.

5. The arrangement of claim 2, wherein said protuberances comprise individual balls oriented substantially perpendicular to the surface of the cooling fins and angled to the fluid flow.

6. A clutch cover comprising a containment of heat conductive material wherein an outer surface of said containment comprises cooling fins which extend over said outer surface and which represent a plurality of webs connected at one of their edges with said outer surface of said containment, said cooling fins extending essentially perpendicular therefrom, said cooling fins each having two faces, said web-like cooling fins comprising on at least one of their faces turbulence-creating formations effective to obtain a turbulent flow of a cooling fluid along surfaces forming channels created by adjacent webs, the formations having at least one edge oriented substantially perpendicular to the flow of the cooling fluid whereby a surface of said formations which is exposed to said fluid flow is arranaed in angular relationship to said fluid flow.

7. The containment of claim 6, which is a cover of a viscous fan clutch of a vehicle.

8. The containment of claim 7, wherein the cooling fluid is ambient air which impinges during movement of the vehicle axially on the cover of the fan clutch, whereafter it is directed radially outwards between cooling fins arranged radially outwardly from a central point.

9. A cover and viscous fan clutch assembly for dissipating heat from the cover to a cooling fluid flowing thereover, the assembly comprising:

a cover;

a viscous fan clutch;

a plurality of radially extending cooling means for cooling the cover having means for flowing the cooling fluid therebetween;

means for disrupting the cooling fluid flow in the flow means between cooling means effective to obtain a non-laminar flow of fluid, said means having at least one edge oriented substantially perpendicular to the flow of the cooling fluid whereby a surface of said means which is exposed to said fluid flow is arranged in angular relationship to said fluid flow.

10. A method for dissipating heat from a cover of a viscous fan clutch with a cooling fluid flow, the method comprising:

arranging a plurality of radially extending cooling fins on an outer surface of the cover to define a plurality of fluid channels therebetween through which the cooling fluid flows;

disrupting the cooling fluid flow in the fluid channels with a plurality of turbulence-creating formations disposed on the cooling fins and effective to induce non-laminar flow, the formations having at least one edge oriented substantially perpendicular to the flow of the cooling fluid whereby a surface of said formations which is exposed to said fluid flow is arranged in angular relationship to said fluid flow.

11. A method for dissipating heat according to claim 10, wherein the plurality of turbulence-creating formations comprise protrusions formed the surfaces of the cooling fins for creating the non-laminar flow of fluid.

12. A method for dissipating heat according to claim 11, wherein the protrusions comprise profiled bars extending generally perpendicular to the fluid flow.

13. A method for dissipating heat according to claim 10, wherein the viscous fan clutch comprises two clutch plates having a fluid therebetween and the disrupting of the fluid flow is effective to decrease the temperature of the fluid between the clutch plates.