Automotive oil cooler

• US 4,004,634 A
• Filed: 05/06/1975
• Issued: 01/25/1977
• Est. Priority Date: 05/06/1975
• Status: Expired due to Term

• Current Assignee: Wolverine Tube Incorporated
• Original Assignee: Universal Oil Products Company (Honeywell International Inc.)
• Inventors: Habdas, Edward P.
• Primary Examiner(s): Davis, Jr., Albert W.
• Assistant Examiner(s): Richter, Sheldon
• Application Number:
  US05/574,989
• Time in Patent Office: 630 Days
• Field of Search: 165/140, 165/141, 165/154, 165/155, 165/156, 184/104 B
• US Class Current: 165/155
• CPC Class Codes: F28D 7/106 consisting of two coaxial conduits or modules of two coaxial conduits
• CPC Class Codes: F28F 1/36 the means being helically wound fins or wire spirals
• CPC Class Codes: F28F 9/0234 having a second heat exchanger disposed there within, e.g. oil cooler

Abstract

Submerged oil cooler for automotive vehicles requires only two principal parts but can provide more heat transfer at a lower pressure drop than conventional oil coolers which utilize three principal parts. In a preferred embodiment, an outer tube having a plurality of longitudinal flutes which are periodically transversely indented is press fit over an inner tube having a helically finned outer surface. The tubes are sealed at their ends so as to define an extended annular flow channel for oil between the tubes, while permitting engine coolant in which the cooler is submerged to flow through the inner tube. A modified arrangement substitutes corrugated tube for the finned inner tube with a resulting cost saving in material but with a small increase in pressure drop and a small loss in heat transfer efficiency.

Claims

1. In a submerged oil cooler for automotive vehicles comprising a hollow inner length of tubing through which engine coolant may flow and an outer length of tubing sealed at its ends to the inner tubing and having an inner surface which cooperates with the outer surface of the inner length of tubing to define a generally annular flow passage for oil which may pass through inlet and outlet fittings at opposed ends of the cooler, the improvement wherein said inner length of tubing includes a helically convoluted outer surface and said outer length of tubing includes a plurality of generally axially extending flutes which engage said helically convoluted outer surface, the crests of said flutes being periodically transversely indented along the axial length thereof to a depth less than the depth of the flutes.

2. A submerged oil cooler in accordance with claim 1 wherein the inner length of tubing has helically convoluted, integral fins extending from its outer surface.

3. A submerged oil cooler in accordance with claim 1 wherein the inner length of tubing has helically convoluted corrugations on its outer surface.

4. A submerged oil cooler in accordance with claim 1 wherein said plurality of generally axially extending flutes are helically corrugated to form transverse indentations in said flutes.

5. A submerged oil cooler in accordance with claim 1 wherein said outer length of tubing contains between about 12 and 24 flutes.

6. A submerged oil cooler in accordance with claim 1 wherein said outer tubing has about 16 flutes which are about 0.070 in. deep, the crests of said flutes being indented about 0.036 in. deep at an axial pitch of about 0.2 in., and wherein said inner length of tubing includes about 26 integral, helically convoluted fins per inch on its outer surface.

7. A submerged oil cooler in accordance with claim 1 wherein said flutes have a depth of from about 0.040-0.100 inches and are indented to a depth of about 0.030-0.090 inches.

8. A submerged oil cooler in accordance with claim 7 wherein said indentations are axially spaced at a pitch of about 0.2-0.8 inches.

9. A submerged oil cooler in accordance with claim 8 wherein said inner length of tubing includes from about 11-26 integral fins per inch of length.

10. A submerged oil cooler in accordance with claim 8 wherein said inner length of tubing is generally smooth except for a helical corrugation in its wall having a depth of about 0.030-0.065 inches and a pitch of about 0.25-0.75 inches.