Powertrain assembly and integral truss oil pan therefor

• US 7,219,642 B1
• Filed: 02/10/2006
• Issued: 05/22/2007
• Est. Priority Date: 02/10/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Beikmann, Randall S., Kwiatkowski, Adam S., Curtis, Jeffrey D., Brown, Julie A.
• Primary Examiner(s): Cronin; Stephen K.
• Assistant Examiner(s): WILSON, AARON NOEL
• Application Number:
  US11/352,936
• Time in Patent Office: 466 Days
• Field of Search: 123/193.R, 123/195.C, 123/195.A
• US Class Current: 123/195.00C
• CPC Class Codes: F01M 11/0004 Oilsumps
• CPC Class Codes: F01M 2011/002 with means for improving the stiffness
• CPC Class Codes: F01M 2011/0054 Fastening to the cylinder block
• CPC Class Codes: F01M 2011/0058 Fastening to the transmission

Abstract

A cast oil pan is connected between en engine crankcase and a lower end portion of a transmission bellhousing. Oil pan side walls each incorporate an integrally cast truss extending between an end flange of the oil pan and adjacent portions of an upper flange to stiffen the connection of the engine crankcase with the transmission bellhousing. Each truss includes a horizontal rail, a plurality of bolt columns extending between the horizontal rail and the upper flange adjacent corresponding bolt openings. Diagonal ribs extend from the oil pan flange generally toward the peripheral end flange. Oil pan bolts at the truss locations pass through the horizontal rail and the oil pan upper flange adjacent the bolt columns so that bolt clamping forces are carried through the bolt columns. The heads of the bolts are positioned below the horizontal rail accessible by power tools for securing and removing the bolts.

Claims

1. A powertrain assembly for automotive use comprising:

an engine including a crankcase for supporting a power producing mechanism, the crankcase including a peripheral lower face for mounting an oil pan and a rear mounting face for mounting a transmission bellhousing for connection of the engine mechanism with power transmitting mechanism in a transmission;

a transmission having a bellhousing mounted on the rear mounting face; and

a cast oil pan including peripheral side, front and rear end walls and a bottom wall defining a cavity for retention of engine oil, the oil pan having a peripheral upper flange and a peripheral end flange, the upper flange mounted to the peripheral lower face of the crankcase by oil pan bolts extending through openings in the upper flange at longitudinally spaced locations along each flange, and a lower portion of the transmission bellhousing mounted against the peripheral end flange of the oil pan;

the oil pan side walls each incorporating an integrally cast truss extending between the end flange of the oil pan and the adjacent portions of the upper flange to stiffen the connection of the engine crankcase through the oil pan to the lower portion of the transmission bellhousing, each truss including a horizontal rail extending generally parallel to the oil pan upper flange and including bolt openings aligned with corresponding bolt openings in the upper flange, a plurality of bolt columns extending between the horizontal rail and the oil pan upper flange adjacent the corresponding bolt openings of at least selected locations, and a plurality of diagonal ribs extending from the oil pan flange generally toward the peripheral end flange;

wherein the oil pan bolts at the truss locations are extended to pass through the horizontal rail and the oil pan upper flange adjacent the bolt columns so that the bolt clamping forces are carried through the bolt columns to the pan upper flange and the heads of the bolts are positioned below the horizontal rail accessible by power tools for securing and removing the bolts.

2. An assembly as in claim 1 wherein some of the diagonal ribs extend directly from adjacent longitudinally spaced bolt openings in the oil pan upper flange to adjacent portions of the rear mounting flange.

3. An assembly as in claim 2 wherein others of the diagonal ribs extend directly from adjacent upper flange bolt openings to the openings of longitudinally spaced bolts in the horizontal rails for stiffening the sidewall structure and distributing bending loads on the rear mounting flange to further locations of the oil pan mounting flange.

4. An assembly as in claim 1 wherein the oil pan is formed as a die casting.

5. A cast oil pan including peripheral side, front and rear end walls and a bottom wall defining a cavity for retention of engine oil, the oil pan having a peripheral upper flange and a peripheral end flange, the upper flange including bolt openings at longitudinally spaced locations along each flange and the peripheral end flange adapted to connect with a lower portion of a transmission bellhousing;

the oil pan side walls each incorporating an integrally cast truss extending between the end flange of the oil pan and the adjacent portions of the upper flange to stiffen the connection of the upper flange with the end flange, each truss including a horizontal rail extending generally parallel to the oil pan upper flange and including bolt openings aligned with corresponding bolt openings in the upper flange, a plurality of bolt columns extending between the horizontal rail and the oil pan upper flange adjacent the corresponding bolt openings of at least selected locations, and a plurality of diagonal ribs extending from the oil pan flange generally toward the peripheral end flange;

wherein the oil pan bolt openings at longitudinally spaced truss locations are adapted to receive bolts extended to pass through the horizontal rail and the oil pan upper flange adjacent the bolt columns so that bolt clamping forces are carried through the bolt columns to the pan flange and heads of the bolts are positioned below the horizontal rail accessible by power tools for securing and removing the bolts.

6. An oil pan as in claim 5 wherein some of the diagonal ribs extend directly from adjacent longitudinally spaced bolt openings in the oil pan upper flange to adjacent portions of the rear mounting flange.

7. An oil pan as in claim 6 wherein others of the diagonal ribs extend directly from adjacent upper flange bolt openings to the openings of longitudinally spaced bolts in the horizontal rails for stiffening the sidewall structure and distributing bending loads on the rear mounting flange to further locations of the oil pan mounting flange.

8. An oil pan as in claim 5 formed as a die casting.

9. An oil pan as in claim 5 and including an oil sump at an end adjacent to the peripheral end flange, wherein the trusses are integral with portions of the side walls defining portions of the oil sump and extending outward to avoid substantially reducing the internal volume of the oil pan.

10. An oil pan as in claim 5 and including an oil sump at an end opposite from the peripheral end flange, wherein the trusses are integral with portions of the side walls defining shallower portions of the pan connecting with the oil sump and extending outward to avoid substantially reducing the internal volume of the oil pan.