US2875739A - Camshaft drive for internal combustion engines - Google Patents

Description

March 3, 1959 w. CQMARCHAND 2,

CAMSHAFT DRIVE FOR INTERNAL COMBUSTION ENGINES Filed June 18, 1956 7 1 2 Sheets-Sheet 1 END WALL PLANE FIGA.

INVENTOR.

7 ATTOEYS March 3, 1959 w. c. MARCHAND 2,875,739

. CAMSHAFT DRIVE FOR INTERNAL COMBUSTION ENGINES Filed Jung 18, 1956 I 2 Sheebs-Sheec 2 M/fim (f Marabua 7 ATTOR EYS United States Patent CAMSHAFT DRIVE FOR INTERNAL COMBUSTION ENGINES William C. Marcl1and, Detroit, Mich., assignor, by mesue assignments, to Continental Motors Corporation, Muskegon, Mich, a corporation of Virginia Application June 18, 1956, Serial No. 592,191

4 Claims. (Cl. 123-55) This invention relates to camshaft drives for internal combustion engines generally of the V-type, and more particularly to an improved camshaft drive operated substantially inwardly of the end of the engine crankcase.

In the development of internal combustion engines, particularly larger engines for use in tanks, trucks, and similar heavy equipment, it is extremely desirable to construct the most compact power plant possible without sacrificing power and economy. The crankcase and gearcase housings and mechanisms comprise the major bulk of the engine, and generally in the V-type line the gear case housing, holding the accessory and carnshaft driving mechanisms, is to be found at one end of the crankcase, or if not completely so mounted, some of the mechanism such as the camshaft drive will be found extended beyond the end plane of the crankcase proper. This adds materially to the length, hence the bulk, of the engine, and requires more complex transmission drive mounting. With V-type engines, it has been found feasible to locate accessories and the accessory drive within the V and generally inwardly of the plane of the crankcase end wall. However, since the camshafts are mounted to overlie the cylinders, the driven end will extend to a point possibly beyond or outwardly of the end wall plane, and heretofore the camshaft driving means, whether connected to the crankshaft directly or through an. intermediate mechanism, has also been disposed outwardly of the crankcase end wall.

An object of the present invention is to permit construction of a more compact V-type internal combustion engine by providing a camshaft drive operatively connected to an accessory driving means inwardly of crankcase end wall plane.

Another object of the invention is to provide a compact V-type engine construction by operating the camshaft drive from an accessory driving means positioned within the V of the cylinder banks.

A further object of the invention is to improve V-type engine constructions by providing a crankcase of mini mum longitudinal dimensions having a crankshaft driven accessory and camshaft driving means located intermediate the cylinder banks and substantially inwardly of the crankcase end wall plane.

A still further object of the invention is to improve V-type engine construction by providing a minimum length crankcase with an accessory and camshaft driving means mounted exteriorly of the crankcase within the V formed by the banks of cylinders and inwardly of the crankcase end wall planes.

For a more complete understanding of the invention, reference may be had to the accompanying invention, reference may be had to the accompanying drawings il lustrating a preferred embodiment of the invention in which like characters refer to like parts throughout the several views and in which:

Fig. 1 is an elevational end view, partially cutaway, of a preferred type of internal combustion engine utilizing the invention,

6 Patented Mar. 3, 1959 2 I Fig. 2 is a fragmentary elevational side view of the engine, partly cut away to show an end of the crankshaft, Fig. 3 is a fragmentary top view of the engine partly in section, and

Fig. 4 is an enlarged section taken substantially on. the line 4-4 of Fig. 1.

An internal combustion engine 10 is illustrated, as having a crankcase structure 11 provided with a top ac.- cessory mounting surface 12, inclined cylinder mounting surfaces 13, and an end wall 14 lying in the. plane. 9 indicated in Figs. 3 and 4. The V-type engine configuration is preferably shown, although it is apparent that the invention may be provided in other engines such. as the horizontally opposed type.

A crankshaft 15 is supported in the crankcase and is provided with a driving means such as a large gear in closely adjacent the inside of the end wall 11. Various accessories such as fuel injection pumps 17 and cooling fan assemblies 18 are disposed in the engine V between cylinders 19. An accessory drive shaft assembly 20 is supported by bearings 21 in an accessory shaft housing 22 mounted on the upper surface 12 of the crankcase 11. a

The accessory drive shaft assembly 20 preferably comprises an, outer hollow shaft 20a and an inner shaft 20b, the outer shaft 28a carrying a driven gear 25 engaged with the crankshaft gear 16 and a driving bevel gear 26 inwardly of the driven gear 25. This shaft, although having nothing to do with the present invention, is adapted to provide both rigid and slightly flexible drive to the various accessories.

Camshaft driving shafts 27' are supported by bearings 28 in tubular housings 29,. extending substantially laterally from the accessory drive shaft assembly and be.- ing inclined outwardly of the engine with respect to the crankcase end wall plane.

The two banks of engine cylinders 19 are provided with valve operating mechanism housings 30', and camshafts 31, overlie the cylinders 19, extending through the housings 30 to operate the valves (not shown). The. camshafts, 31 are housed within tubes 32 and a driven. bevel gear 33 is secured by any means to the end of each camshaft.

A driven gear 35 and a driving gear 36 are secured to each camshaft driving shaft, and are respectively op erably engaged with the accessory drive shaft bevel gear 26 and the camshaft bevel gear 33.

The aforesaid accessories 17 and 18 are drivingly connected to the accessory drive shaft 20 by any suitable means, an example of which are engaged gears 35 and 36, gear 35 being secured to the shaft 20b and gear 36 being secured to a fan drive shaft 37.

It will be seen that by utilizing the inclined camshaft driving shafts 27 driven from the accessory drive shaft in the manner illustrated, it is possible to contain all the accessory and camshaft driving means substantially inwardly of the crankcase end wall plane, thus providing a very compact engine having a crankcase of minimum dimensions and having the mechanical components shown in readily accessible positions.

Although I have described but one preferred embodiment of the invention, it will be apparent to one skilled in the art to which the invention pertains that various changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A camshaft drive means for a generally V-type internal combustion engine having a crankcase provided with an end wall, a crankshaft supported by said crankcase and provided with a drive gear closely adjacent said as /arse end wall, said end wall lying in a plane normal to the crankshaft axis, two banks of engine cylinders secured to said crankcase and each bank provided with a camshaft disposed parallelwith said crankshaft axis, and an accessory drive shaft disposed intermediate said cylinder banks and provided with a driven gear closely adjacent said end wall plane and operably engaged with said crankshaft drive gear, said camshaft drive means comprising a driven gear carried by each of said camshafts and disposed substantially in a plane containing said crankshaft drive gear and accessory shaft driven gear and closely adjacent said end wall plane, a camshaft drive gear carried by said accessory drive shaft inwardly of said accessory drive shaft driven gear and offset from the plane containing said crankshaft drive gear, said accessory shaft driven gear andsaid camshaft driven gears, and driving means operably connecting said camshaft drive gear and said camshaft driven gears.

2. A camshaft drive means for a generally V-type internal combustion engine having a crankcase provided with an end wall, a crankshaft supported by said crankcase and provided with a drive gear closely adjacent said end wall, said end wall lying in a plane normal to the crankshaft axis, two banks of engine cylinders secured to said crankcase and each bank provided with a camshaft disposed parallel with said crankshaft axis, and an accessory drive shaft disposed intermediate said cylinder banks and provided with a driven gear closely adjacent said end wall plane and operably engaged with said crankshaft drive gear, said camshaft drive means comprising a driven gear carried by each of said camshafts and disposed substantially in a plane containing said crankshaft drive gear and accessory shaft driven gear and closely adjacent said end wall plane, a camshaftdrive gear carried by said accessory drive shaft inwardly of said accessory drive shaft driven gear and offset from the plane containing said crankshaft drive gear, said accessory shaft driven gear and said camshaft driven gears, and a drive shaft inclined outwardly toward said end wall and operably connecting each of said camshaft driven gears and said camshaft drive gear.

3. A camshaft drive means for a generally V-type internal combustion engine having a crankcase provided with an end wall, a crankshaft supported by said crankcase and provided with a drive gear closely adjacent said end wall, said end wall lying in a plane normal to the crankshaft axis, two banks of engine cylinders secured to said crankcase and each bank provided with a camshaft disposed parallel with said crankshaft axis, and an accessory drive shaft disposed intermediate said cylinder banks andprovided with a driven gear closely adjacent said end wall plane and operably engaged with said crank shaft drive gear, said camshaft drive means comprising a driven gear carried by each of said camshafts and disposed substantially in a plane containing said crankshaft drive gear and accessory shaft driven gear and closely adjacent said end wall plane, a camshaft drive gear carried by said accessory drive shaft inwardly of said accessory drive shaft driven gear and offset from the plane containing said crankshaft drive gear, said accessory shaft driven gear and said camshaft driven gears, a pair of diverging drive shafts each having a gear at the inner end thereof drivingly engaged with said camshaft drive gear and a gear at the outer end drivingly respectively engaged with each of said camshaft driven gears.

4. A camshaft drive means for a generally V-type internal combustion engine having a crankcase provided with an end wall, a crankshaft supported by said crankcase and provided with a drive gear closely adjacent said end wall, said end wall lying in a plane normal to the crankshaft axis, two banks of engine cylinders secured to said crankcase and each bank provided with a camshaft disposed parallel with said crankshaft axis, and an accessory drive shaft disposed intermediate said cylinder banks and provided with a driven gear closely adjacent said end wall plane and operably engaged with said crankshaft drive gear, said camshaft drive means comprising a driven gear carried by each of said camshafts and disposed substantially in a plane containing said crankshaft drive.

gear and accessory shaft driven gear and thereby adjacent said end wall plane, a camshaft drive gear carried by said accessory drive shaft inwardly of said accessory-drive shaft driven gear and offset from the plane containing said crankshaft drive gear, said accessory shaft driven gear and said camshaft driven gears, a pair of diverging drive shafts each having a gear at the inner end thereof drivingly engaged with said camshaft drive gear and a gear at the outer end drivingly respectively engaged with each of said camshaft driven gears, said drive shafts diverging outwardly in a V and inclined from the inner end outwardly toward said end wall plane.

References Cited in the file of this patent UNITED STATES PATENTS

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