Engine unit with lubricant cooling

• US 4,393,922 A
• Filed: 01/22/1981
• Issued: 07/19/1983
• Est. Priority Date: 01/22/1980
• Status: Expired due to Fees

• Current Assignee: Damiler-Benz AG Germany
• Original Assignee: Daimler-Benz AG (Mercedes-Benz Group AG)
• Inventors: Wulf, Helmut, Bahrle, Friedrich
• Primary Examiner(s): Yeung, James C.
• Assistant Examiner(s): FOCARINO, MARGARET ANN
• Application Number:
  US06/227,372
• Time in Patent Office: 908 Days
• Field of Search: 165/41, 165/51, 165/104.26, 74/606 A, 74/607, 184/104 A, 184/104 B, 123/41.33, 92/153
• US Class Current: 165/41
• CPC Class Codes: F01M 2011/0025 with heat exchangers
• CPC Class Codes: F02F 7/006 Camshaft or pushrod housings
• CPC Class Codes: F16H 57/0415 Air cooling or ventilation; Heat exchangers; Thermal insulations
• CPC Class Codes: F16H 57/0483 Axle or inter-axle differentials
• CPC Class Codes: F28D 15/0233 the conduits having a particular shape, e.g. non-circular cross-section, annular F28D15/0241, F28D15/0266 take precedence
• CPC Class Codes: F28D 15/0275 Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores
• CPC Class Codes: F28F 2215/06 Hollow fins; fins with internal circuits
• CPC Class Codes: Y10T 74/2189 Cooling

Abstract

An engine unit adapted to be lubricated by a liquid lubricant with a lubricant reservoir as well as a lubricant cooling. The cooling takes place by way of at least one heat pipe, with the heat pipe having a heat absorbing portion adapted to be exposed to the lubricant and a heat transmitting portion adapted to be exposed to surrounding air. The engine unit may be an internal combustion engine, a gear system such as a change-speed transmission or differential transmission of a vehicle drive axle.

Claims

1. A differential gear of a vehicle driving axle lubricated by means of a liquid lubricant, having a lubricant collecting pipe as well as having a lubricant cooling system, comprising a heat pipe, with its heat-receiving part, that is circular in its cross section, projecting directly into the lubricant collecting space in an area of an especially high reflux current or turbulence of the lubricant in the collecting space;

the heat-emitting part of the heat pipe, in the operational installation position of the differential gear, is geodetically higher than its heat-receiving part; and

the heat-emitting part of the heat pipe is formed in a plate-shaped manner, of two sheet-metal plates that are welded to one another so that they are hermetically tight, with the heat-emitting part being exposed to ambient air and being aligned in the driving direction of the vehicle, where the surface in the heat-emitting part of the heat pipe that can be used for the formation of the condensate is larger than the surface in the heat-receiving part that can be used for the evaporation.

2. The apparatus according to claim 3, wherein the heat absorbing portion of the at least one heat pipe means is disposed in an oil pan means, and a capillary means is disposed interiorly of the at least one heat pipe means in the oil pan means for enabling a return transport of a heat transfer medium of the heat pipe means.

3. The apparatus according to claim 1, wherein a heat transfer medium is accommodated in the at least one heat pipe means under a pressure such that the heat transfer medium is vaporized only at least at one of an operating temperature or above an operating temperature of the lubricant.

4. The apparatus according to claim 1, wherein the at least one heat pipe contains a heat transfer medium under pressure such that the heat transfer medium is vaporized and the heat transfer medium is accommodated in the at least one heat pipe means under a pressure such that the heat transfer medium is vaporized only at least at one of an operating temperature or above an operating temperature of the lubricant.