US2647494A - Internal-combustion engine casing construction - Google Patents

Description

Aug. 4, 1953 I M. WARE 2,647,494

INTERNAL-COMBUSTION ENGINE CASING CONSTRUCTION Filed'April 19. 1949 3 Sheets-Sheet 1 7 CIIIIIIIIIII,

' INVENTOR. BY Mflw m fmzzdza ATTORNEYS Aug. 4,' 1953 M. WARE INTERNAL-COMBUSTION ENGINE CASING CONSTRUCTION Filed April 19. 1949 3 Sheets-Sheet 2 INVENTOR.

ATTORNEYS M. WARE INTERNAL-COMBUSTION ENGINE CASING CONSTRUCTION Filed April 19. 1949 Aug. 4, 1953 5 Sheets-Sheet 3 INVENTOR.

ATTO RN EYS Elle Patented Aug. 4, 1953 INTERNAL-COMBUSTION ENGINE CASING CONSTRUCTION Marsden Ware, Huntington Woods, Mich., as signor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application April 19, 1949, Serial No. 88,246

1 Claim.

This invention relates to internal combustion: engines and particularly to an improved crankcase construction for an internal combustion en gine of the high speed type.

Numerous attempts have heretofore been m de to develop an engine crankcase which at one time is sufficiently rigid to resist distortion resultin from the application thereto of forces from the associated crank shaft and of such light weight that the engine may be utilized in aircraft or in any other vehicle or place where it is important to maintain the ratio of weight to horsepower as low as possible. It has been suggested that such a crankcase may With advantage be fabricated of non-ferrous metals, that the walls and webs be relatively thin, and that elements of high tensile strength be utilized in association with the transverse webs for the purpose of placing the metal of the webs under initial compression and for ensuring that those webs, and the crankcase gen-' erally, are not subjected to excessive strains resulting from the transmission thereto, from the crank shaft, of impressed forces which vary widely in direction, magnitude and point of application as the supported crank shaft revolves athigh speed.

The present invention contemplates an internal combustion engine crankcase which embodies, in association with the transverse webs of the cas ing, tension members of the general type heretofore proposed, such members, however, being so disposed in relationship to the webs with which they are associated that each such web has great strength for its weight, and theengine casing as a whole has the greatest possible rigidity for a I.

given weight and given engine power.

- While the invention may be employed with advantage in the crankcase constructions of engines of widely varying types, it is perhaps of greatest utility when incorporated in an engine casing in mounted upon and housed largely within such extension. The engine casing webs extend trans.

versely of the axis of the casing and the lower portion of such web, to which a crank shaft bear-"- ing isimmediately secured, is especially subject to strain due to crank shaft forces imposed thereon;

I It is of first importance, therefore, that this portion of each web be designed and constructed in such manner that it may successfully resist all imposed forces without at the same time being so -heavy in section that the weight of the engine casing as a whole becomes excessive.

The present invention contemplates the application of tensioning members to those portions of the casing webs located within the crankcase body in such manner that substantially all portions of this web are placed under initial compression and are supported adequately at all times. The reinforcing elements or tension rods pass through the web in various directions and'preferably two tension members extend transversely of the web, one above and one below the crank shaft bearing and two are disposed vertically, one to either side of the crank shaft bearing. In every instance, however, the reinforcing element is located Within an elongated cylindrical aperture of continuous nature formed in the web with which the element is associated, the web being enlarged or thickened where necessary to provide a section adapted to be pierced by such an aperture.

The tension rods are so formed that each makes contact at several points along its length with the wall of the cylindrical aperture through which it extends, in order to prevent any vibration of the rod relatively to the web, and the tensioning elements extend completely through the web. No tension rod has threaded relationship with the web with which it is associated but each is provided with a head at one end and a nut at the other, or with nuts at both ends, to engage the lvention selected for disclosure by way of exa pl Figure 1 is a transverse section through the engine crankcase, the section being taken intermediate two cylinders;

Figure 2 is a similar section, taken on the axis of one of the cylinders;

Figure 3 is a longitudinal section through a portion of the engine casing, showing the crank shaft and several cylinders in elevation, the connecting rods being broken away;

. Figure 4 is a top plan view of a portion of the crankcase with attached cylinders;

. Figure 5 is a section on line 5-5 of Figure 1;

Figure Sis a section on line B6 of F gure 2;

' to laterally deflect.

Figure 7 is a section on line 'l-J of Figure and Figure 8 is a section on line 8-8 of Figure 6.

The body of the engine casing is generally indicated at B, the upward extension thereof at E and the oil retaining pan, suitably attached to the body B, is indicated at P. The side walls 10 and H of the casing body are upwardly and inwardly curved from elevations just above the lower terminal flanges 12 and I3, to which the pan P is attached, and the lower edges of the flat inclined outer walls Hi and I5 and likewise the lower edges of the parallel vertical inner walls I6 and ll, of the crankcase extension E, are integral with the upper margins of the side walls, as shown in Figures 2 and 3. The converging walls l4 and I6 merge at their upper ends to form an elongated solid section I 8 and likewise the upper margins of the converging walls 55 and IT merge to form an elongated solid section 19.

The side walls It and H of the crankcase body B are connected by bridging webs W and each of these webs has an upward extension or prolongation W which bridges and connects the side walls l5 and ll of the crankcase extension E, one such bridging web being shown, mainly in elevation but partially broken away, in Figure 1 of the drawings, and several being shown in section in Figures 3, 6 and 7. The body B of the crankcase is of steel or lighter non-ferrous metal and is formed by a casting operation so that the side walls and transverse webs are integral parts of a rigid structure. The lower or major portion of each such web constitutes a support for the upper half of a crankcase bearing sleeve, indicated at 25, the lower half of sleeve 25 resting upon and being supported by the bearing block 26 which is generally rectangular and fits closely within a downwardly opening rectangular recess formed in the lower portion of the associated web.

The tensioning rods employed in association with each web are, in the form of the invention illustrated, four in number, two being disposed vertically and two horizontally, the vertically recesses which receive the vertical tension rods 28 and 29 are disposed equi-distantly from the axis of the crank shaft bearing 25 and upon opposite sides thereof.

As most clearly shown in Figures 6 and 7 the axes of these tensioning members are located in a vertical plane which bisects the associated symmetrically formed web. The tension members 30, of which there are two associated with each web, and the two adjacent tension members 3!, are disposed in horizontally extending parallel cylindrical apertures formed in horizontally extending thickened portions of the web which may be most clearly seen in Figure 3 of the drawings, the tension rods of each pair being disposed upon opposite sides of the vertically extending tension rods 28 and 29, as may be most clearly perceived in Figures 5 and 7.

It will thus be seen that the crank shaft bearing block 26 is pierced by four cylindrical ten- The elongated cylindrical sion rod receiving apertures, two to receive horizontal tension rods 3| and two to receive vertical tension rods 28 and 29, and it is thus firmly supported, becoming, in effect, an integral portion of the web after the assembly has been completed. Tension rods 28 and 29 are provided at their upper ends with integral heads 28a and 23a and at their lower ends with lock washers 28b and 29b and nuts 28c and 290. The tension rods 3| are provided with integral heads 3la, lock washers Sit and tightening nuts 3lc, rods 30 being of similar type. Each rod receiving aperture extends from one edge of the web with which it is associated entirely through the web to the opposite edge so that, when tension is applied to the tension rod positioned within that aperture by turning the tensioning nut provided, the metal of the web intermediate the head and tensioning nut of each rod is placed under compression.

By reason of the fact that the tensioning rods are disposed in the manner described, with a plurality of rods extending transversely of each web, and a plurality extending vertically therethrough, practically all portions of each web are placed under compression and those portions of the web in the immediate vicinity of the crank shaftbearing 25 are, in particular, placed under compression. As a result, and further by reason of the fact that each web is reduced in thickness where the force of compression applied thereto are of reduced amplitude, an extremely rigid support for the crank shaft bearing is provided the weight of which, however, is the lightest possible for a crankcase having the required strength and rigidity.

Each of the engine cylinders is indicated generally at A and is provided with a peripheral flange A which rests upon the horizontal head H of the upwardly extending portion E of the casing, the flanges A being secured to the casing by bolts 35 which enter recesses formed in the ribs i8 and IQ of the casing and bolts 38 which have threaded engagement with the threaded walls of bolt receiving apertures formed in the web extensions W. Projecting upwardly from the upper surface of each cylinder end Wall are a plurality of bosses 38 each having an upwardly facing annular shoulder adjacent its upper end. A circular plate 39 is provided with a series of apertures which receive the reduced upper ends of these bosses, the plate resting upon the shou ders of the respective bosses and being welded to each by a circular weld. There is thus provided at the end of the cylinder a water space and this space is in open communication with a water space of annular cross section defined by the outer surface of the cylinder wall and the cylindrical jacket 48 welded to the periphery of plate 39 and to an upwardly projecting circular flange integral with the main cylinder flange A.

The lower end of each cylinder is housed within the crankcase extension E and a second water space is defined by the cylinder wall surfaces, the inner faces of walls 5 and H, the flanges A and the water sealing means including a plurality of sealing rings M, 42 and 43 encircling the lower end of each cylinder. Intermediate sealing rings 42 and 43 of each cylinder is a leakage collection groove 44 within which gathers any water which may happen to leak downwardly past seals 4| and 42, any leakage entering groove 44 escaping through drainage duct :35. The upper and lower water spaces communicate with each other through passages 46 formed in the cylinder flanges A.

If desired the several tension rods 28, 29, 30 and 3| may be of uniform section from end to end but are preferably formed as shown in the drawings, the major portion of each rod being, in section, smaller in diameter than the cylindrical aperture through which it extends and being provided with enlargements which maintain it in coaxial relationship with the aperture within which it is housed. These several rod enlargements are indicated at 28d, 29d, 30d and 31d, respectively. By so constructing the tension rods ease of assembly of the rods and webs is promoted.

The crankcase and cylinder construction described and illustrated is simple in design but of great eificiency in actual operation. The metal of that portion of each web which lies within the crankcase proper is under initial compression, as explained, substantially in its entirety due to the conjoint action of the angularly disposed sets of tension rods and the webs are light in section even though subjected to substantial, rapidly repeated, forces constantly varying in direction, imposed thereon by the crank shaft. The cylinders are most securely attached and the simple cooling means formed by assembling the several parts in the manner described is thoroughly effective.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

In an engine, an elongated crankcase comprising a body portion and an upward extension terminating in a flat cylinder flange receiving surface, said body portion and extension having transversely spaced side walls respectively, the side walls of the extension being upward continuations of the side walls of the body, a plurality of parallel webs disposed transversely of the crankcase and rigidly connecting the side walls of both body and extension, each web having a recess in its lower edge to receive a hear.- ing block and having two parallel vertically disposed passages extending therethrough from said recess to said cylinder flange receiving surface, each web having also a plurality of horizontally disposed passages therein, two such passages extending through each side wall and adjacent portion of each web to the bearing block recess formed in that web, and each such horizontal passage on one side of said recess being aligned with one on the other side of the recess, and said pairs of aligned passages being parallel to and on opposite sides of, a plane which includes the axes of the vertically extending passages of the same web, a bearing block in each such recess, each block having two horizontal passages therethrough which register, respectively, with the aforementioned aligned horizontal passages in the web, and two vertical passages which are aligned with and form continuations of the vertical passages inthe web, and tension rods disposed within the aligned passages of bearing blocks andwebs and main taining the blocks and webs in compression.

MARSDEN W ARE.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Mar. 3, 1927

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