US2150535A - Engine structure - Google Patents

Description

March 14, 1939.

48 E \llllllll i ENGINE STRUCTURE 3'Sh eets-Sheet 1 Filed June 6, 1935 Zmventor attorneys March 14, 1939. R. WJNTZER ENGINE STRUCTURE Filed June 6, 1955 s Sheets-Sheet 2 q m n w t. a

March 14, 1939. R. WINTZER- 2,150,535

ENGINE STRUCTURE Filed June 6, 1935 :5 Sheets-Sheet :s

ZSnnehtor (Ittomqs Patented Mar. 14, 1939 UNITED STATES ENGINE STRUCTURE Rudolf Wintzer, Milwaukee, Wis., assignor to Nordberg Manufacturing Company, Milwaukee,

'Wis., a corporation of Wisconsin Application June 6, 1935, Serial No. 25,350

3 Claims.

This invention pertains to engine structures, and relates more particularly to a simple means ,of constructing a light frame for a reciprocating engine, which will support the engine cylinders and shaft in proper relationship.

One of the objects of the invention resides in the provision of means for rigidly tying the crank shaft supporting members to the frame in which the cylinder is mounted and supported, the means for tying the parts together comprising tension members preferably of high grade steel which coact with surrounding compression elements or members. 7

Another object of the invention resides in constructing a rigid cylinder yoke or supporting member which forms the water jacket in part around the cylinder.

A still further object resides in dividing the cylinder transversely of its axis so that the pistons with their rings may be readily inspected without removing the pistons from the lower portion of the cylinder when the yoke above mentioned is removed from the engine, frame-with the upper portion of the cylinder.

A still further object is to attach and mount the upper portion of the cylinder with reference to the yoke so that said yoke and cylinder portion may be readily detached from the engine frame, to expose the rings in the manner just specified, or for any other purpose.

A still further object is to provide means in connection with the tension bolts whereby they are positively stretched to a predetermined degree, thereafter permitting the nuts on the bolts or rods to be set up or tightened by hand.

With these and other objects in View, reference may be had to the annexed drawings, wherein:

Figure 1 is a vertical sectional view on the line I-- I of Fig. 2, with certain parts broken away, illustrating the engine structure of my invention;

Fig. 2, a vertical sectional view taken through the engine at right angles to that of Fig. 1, and looking toward the left, showing one of the cylinders with the piston therein, the section being taken on the line IIII of Fig. 1;

Fig. 3, a perspective view of the engine frame, the pistons and cylinders being omitted, and certain portions of the structure being shown in a detached relationship prior to their final and permanent assembly and connection with the other elements of the frame; 7

Fig. 4, a perspective view of a pair of yokes employed in conjunction with the upper portion of the cylinder;

Fig. 5, a top plan view thereof; I

Fig. 6, a detailed vertical sectional view of one of the rods or columns and its associated elements, with a slightly modified form of means cooperating with the rod for holding it in position when the yoke is removed; and

Fig. 7, a vertical sectional view of an engine employing the frame structure hereinafter set forth in detail and disclosing scavenging and exhaust ports.

In order to build a light weight, high speed i reciprocating engine, it is essential to maintain proper rigidity of the structure and to reduce the weight of the essential parts thereof, as far as possible. It is also quite necessary to reduce the number of parts which enter into the .enginelfi frame, as far as possible.

Many attempts have been made to produce an engine having these qualifications at a reasonable cost, but yet so far as I am aware, this has not been effected. In order to bring about such 20 a satisfactory structure, all the tension and compression which is usually carried by the frame must be reduced to members which take up their respective stresses in a direct line with such strains. The anchorage at either end of such 25 tension members has so far proven unsatisfactory, and while it is a comparatively simple matter to take up the stresses on the lower or crank shaft end of the tension members, the upper ends have usually been attached to a part of the frame 30 to which a cylinder head was independently bolted. The use of separate flanges between the cylinder head and the frame, and the cylinder head and the liner, as well as separate bolts to hold these elements together, produces a heavy 35 structure and brings about unequal stresses.

The present invention-is directed to a frame structure which is supported on its own base and in which the frame is composed of light but adequately strong tension and compression members, the compression members themselves. being rigidly cross-connected both transversely and longitudinally. The compression members also have a shoulder or bearing at their upper end, 1 against which the cylinder supporting entablature abuts, the cylinders being suspended from this entablature. l

The invention is applicable to single, or multicylinder engines, and it is in connection with the latter that it is illustrated. 5

With the foregoing andv other objects and advantages in view, reference is had to the annexed drawings, wherein the reference numeral ll designates the mainbearings, there being three of these as shownin Fig. 3, the framebeing 2 designed for a two-cylinder engine. These bearings, of course, form the support for a crank shaft (not shown) which, in turn, is held against the upper main portion of the bearing shell ll or suitable brasses mounted therein, there being a bearing cap or block 12 located beneath each of said members H, said blocks being positioned between spaced lugs l3 and I4, there being a pair of said lugs for each block. These lugs extend downwardly from a portion of the base frame element designated generally by l5, the outer element whereof extends lengthwise of the frame and is welded at its inner edge or edges as at I6 to the saddle-like member H which overlies the upper portion of the member II and carries the depending lugs l3 and M. This arrangement produces a rigid yet light base for the engine.

Each of the members i1 is formed with an upstanding hollow boss or socketed member 58, upon the upper end of each of which there is mounted a hollow column or.compression member l9, said members l8 and I9 being welded to each other where they contact. Each of the columns or compression elements I9 is provided at its upper end with a collar or bearing element 2!, which, however, is not welded thereto until other of the frame elements have been positioned; or, conversely, the frame elements about to be described, may be assembled and secured to each other, and the columns or compression members IS, with the members 2! permanently secured thereto, dropped down through openings formed in certain of the frame members and then welded to the lugs iii of the base element 11.

Each pair of columns is cross-connected by a web or plate 22, which is also connected by welding to the member ll. Radiating ribs 23 extend upwardly from the member l'l upon each side of the web 22, and are welded thereto. The vertically disposed ribs 23 are also welded at their upper ends to a cross plate or shelf 24, while the other ribs are welded at their upper portions to the columns iii. A web 25 is interpositioned .between each of the adjacent pairs of columns, being welded at its edges to said columns and strengthened as by cross ribs 25 and 21 and the horizontal ribs 28. The web 25 may be provided with an opening as 29 (Fig. 3) to lighten the structure.

Plate 2 is provided with openings, one for each cylinder, which openings are defined by collars or rings 3! which are welded to the plates or shelves 24, radiating ribs 32 extending from said collar or ring to each of the adjacent columns, said ribs being welded thereto, to the shelf or plate 24'and to the ring, thus securely tying all the parts together and rendering the structure stiff and rigid while still being light.

Located above'the transversely extending webs 25 and in parallelism to the plate 24 is a second plate or shelf 33, said plate'being produced with openings through which the compression members or columns H! are initially passed prior to being welded thereto and, likewise, with relatively large openings for the reception of a yoke designed to cooperate with the upper portion of the cylinder, as hereinafter described.

As will be seen upon reference more particularly to Figs. 1 and 3, the shelves or ' elements 24 and 33 extend outwardly beyond the columns, and to those edges of the shelves which lie in parallelism to the crank shaft, there is welded a plate-like element 34, the plate at its lower portion flaring outwardly andbeing welded to the adjacent portion of the member l5. Said member'34 has secured thereto a plurality of pads or feet 35 having part openings extending therethrough which align with openings formed in the bed plate l5 through which bolts may be passed to secure the engine in place.

Upon the opposite side of the shelves 24 and 33 there is also secured by welding a plate 36, likewise having its lower portion flared outwardly and welded at its lower edge to the element [5. It also carries pads or feet 35 having openings therein which align with openings in the bed plate to secure the engine in position.

Upon reference to Fig. 1, it will be noted that the right hand side of the shelf 33 extends outwardly to an extent greater than that on the left, and there is welded to the outer portion thereof a plate-like element 31 which extends downwardly in a vertical direction with its lower end turned inwardly toward the shelf 24 where it is welded to the side plate or wall 36. This forms a boxlike structure which may be utilized as a scavenging header.

Such header is shown in Fig. '7 and is denoted generally by 371 in which there are present check valves of ordinary form denoted by 31 These valves are essential because the heights of the scavenging ports and the exhaust ports, denoted, respectively, by 31 and 31 are identical, and it is clear that when the piston uncovers both sets of ports simultaneously, a pressure greater than that existing in the scavenging header obtains within the. cylinder and for that reason would pollute the scavenging air unless the valves were utilized. No claim to any such arrangement is made in this case, however, as the same is old. The frame structure is of the same form as that shown'in the other figures.

Plate 33 has one or moreannular openings formed therein according to the number of cylinders present in the engine. Mounted in each of these openings and extending downwardly below the shelf 33' is an elongated sleeve-like element 38 (see more particularly Fig. 2), said element being welded to the shelf 33 to maintain it in rigid relation with reference thereto.

The engine cylinder is formed of two parts, 39 and M, the lower end whereof is made of such external diameter as to make a close and relatively tight fit with the ring-shaped member 3i into which, it extends (see Fig. 2). Mounting of the lower portion of the cylinder within the ringshaped member permits the cylinder to expand downwardly, and prevents distortion of the parts.

Throughout the major portion of the upper of the member 39 and formed exteriorly thereof is a chamber 42, the outer wall of which throughout the length of the member 38 is of such diameter as to make a close fit with'the interior of said member 38. The member 38 at its upper end is provided with a packing recess into which extends a gland 43, the gland being held in position by set screws or bolts Mi mounted in lugs extending outwardly from the body of a yoke or head piece denotedv generally by 45, and hereinafter more fully described. Said yoke is designed to hold the upper end of the cylinder, and the cylinder sections are held together in close gastight relation by through bolts 43 (see Fig. 2), a gasket as 4'! being placed between the machineturned abutting edges of the sections of the cylinder.

The line of juncture, designated by 40, between the cylinder sections may be upon a plane at right angles to the cylinder axis, or, as shown in 2, such line may be sinuous o-rtake the formof a sine wave. This latter formation will-be of par- .ends.

ticular advantage to avoid the development of a ridge which would be produced by wear and which would cause the piston rings'to engage a projecting edge completely around the inside face of the liner in a horizontal plane.

Itmay be pointed out that by the time the piston has moved downwardly inthe cylinder to a point below the juncture line between the upper and lower sections, the pressure obtaining within the cylinder will have been materially reduced, and, consequently, fear of leakage between the piston sections need not be considered. This is particularly true where the joint is carefully made and a gasket is embodied in the structure.

The cylinder section 4! is held in position within the yoke by machine bolts 48 which extend through the yoke and into the upper portion of the cylinder.

The exterior of'the head section M of the cylinder is formed with a helical rib 49 extending about the same, producing a tortuous channel in communication with the chamber 32 for the cooling liquid or medium. An opening 52 is shown as extending through the upper end of the cylinder section 5! and the yoke 55, into which the fuel valve may extend. The yoke pieces are alike in form and are designed to practically abut each other, having semicircular seats 53jformed in the proximate edges through which the tension rods or bolts pass. The proximate edges of said yokes are provided with oppositely disposed seats 45 (Fig. 4), designed to receive a key 56* which serves to lock the yoke'pieces against vertical movement relatively toeach other, and, in effect, to form an unit of the yokes, equalizing strains and stresses throughout the structure. Thus,

when the combustion pressure in one cylinder is at its maximum, that in the adjacent cylinder may be at its minimum, and this inequalityin pressures would, therefore, be taken up completely around the circular portion of the upper face of the yoke.

The members I9 are placed under compression, the members l2 held to their position, and the yokes 45 forced downwardly against the bearing members 2! by the utilization of tension rods 54. Said rods are threaded at their upper and lower At their lower ends they carry nuts 55 which force washers 56 against the lower portion of the member l2. At their upper ends, they pass freely through the bearing members 2!, through the seats 53, rocking Washers being placed thereon above said seats and bearing upon the yoke structure with a nut 5'! overlying the uppermost washer elements, which elements are denoted generally by 58. As will be seen upon reference more particularly to Fig. 6, the lower member or element has a concave upper face while the washer immediately above the same is provided with a convex face complemental in contour to that of the lower member. This permits the parts to rock and find a true fair bearing without placing undue strain upon the rods. A collar 59 is Welded to the rod and rests upon the bearing member 2 i. This assembly of the parts permits the removal of the nuts 5?, the washers, the yoke and the upper portion 4! of the cylinder, without displacement of the rods, inasmuch as the collars 59 would then bear upon the members 2| and prevent descent of the rods.

The various elements are so machined that the bearing elements or abutments 2| are of the same height throughout the engine and form a base upon which the yoke or cylinder supporting head 45 comes to rest, thus insuring an even bearing for the parts throughout.

In light weight engines, it is usual to make the piston of the trunk type, requiring no cross head which makes it necessary that the cylinder take all the side thrust. In case the cylinder is built in a single piece instead of two pieces, as herein shown, it is necessary to provide means tohold the piston central when the cylinder is dropped over the piston. It is also necessary to provide means to permit the rings to enter the cylinder without damaging them, which will require an opening in the enclosure wall as 34 and/ or 36, for piston ring clamping means.

The structure as herein shown and described, permits the removal of the upper part of the cylinder without the difficulty of keeping the piston central, and also provides a means for ready examination of the piston rings by turning the cranks so that the piston at its upper dead center will rise high enough to expose all of the rings above the joint between the upper and lower sections of the cylinder. The construction set forth, moreover, is such that the various rods or bolts 5 3 may be stressed with a definite load, to take up the pressure exerted upon the members I2, occasioned by the pressure exerted within the cylinder.

The preferred form is to provide the bolts as above described with collars or bearing elements as 59, so that the main bearing caps may be securely drawn to place and the crank shaft held in place thereby, while the upper part of the cylinder with its yoke may be removed for inspection. To properly tension these bolts, it has been found important that they be stressed with a definite load which may be brought about by placing an hydraulic jack over the nut, the ram portion of the jack being secured to the bolt or rod at the threads extending beyond the nuts 55 or 51. The general practice is to stress these bolts with a definite pressure and then tighten the nut by hand, thereafter releasing the hydraulic jack. There is never any danger under such conditions intwisting the bolt (i. e., setting up a twisting and tension stress), or to stress the bolts difierently each time a main bearing cap or yoke 45 is removed.

It is, however, diflicult to attach a jack of this form to the bolt below the nut 55 without the use of special equipment. In this instance, the jack is attached above as at '51, in which case, however, the bearing collar 59 cannot be used in connection with the bolt. The arrangement shown in. Fig. 6 may then be employed, wherein a collar as 6| is fixed to or formed upon the bolt adjacent its lower portion and a set screw 62 is thread-ed into the upstanding element l8 of the member ll upon the upper end of which the column is seated and secured. This arrangement when the set screw is turned inwardly beneath the collar permits the collar to come to rest thereon and will then enable the upper end of the bolt to be stretched upwardly away from the set screw.

Placing the rods under tension places the columns under compression, and inasmuch as the various elements of the frame are directly interrelated and welded together, the structure becomes rigid throughout and is not liable to distortion through any strains which may be imparted thereto.

The structure shown in the accompanying drawings and above set forth is designed primarily for use in connection with a single acting engine, whether it be a four or two cycle.

It is also adapted to double acting engines, as will be readily appreciated by those skilled in the art. 7

Various accessory parts have, however, been omitted, as they do not form any essential part of the present invention.

It is also apparent that by utilizing the yoke construction as shown and described, a material suited to the specific work may be employed. For instance, the yoke may be made from cast steel inasmuch as strength and rigidity is a necessary requisite, whereas a liner may be made of cast iron, as that is the best material so far found for liner construction. The usual difficulty in making cast steel parts gas-tight need not be given any particular consideration, as the yoke portion need only to hold tight against the lower water pressure employed for cooling purposes.

What is claimed is:

1. In an engine, the combination of a base; a lower bearing member for the shaft of the engine; a framework composed of a series of interconnected plates extending transversely of the structure; a series of columns extending upwardly from the base and interconnected with said platelik-e members, the columns terminating at a point above the uppermost plate of the frame; a yoke; a cylinder; means securing the upper end of the cylinder to said yoke; and a series of tension rods extending through said columns, through the lower bearing member and coacting with the yoke to hold the same in position upon the upper ends of the columns, said rods also serving to hold the lower bearing member in position and to place the columns under "compression.

2. In an engine, the combination of a base; a series of columns extending upwardly therefrom; a framework directly connected to said base and. to said columns, said framework comprising a series of interconnected horizontally and vertically disposed plates, the uppermost plate lying below the upper ends of the columns; a two-part cylinder mounted in openings formed in the framework; a yoke fixedly secured to the upper portion of the cylinder; means securing the cylinder sections together; and tension rods extending through the colunms and acting upon the yoke to hold the same in position upon the upper ends of the columns.

3. In an engine, the combination of a base; a series of hollow columns extending upwardly therefrom; a framework connected to said base and said columns, said framework comprising a series of horizontally disposed plates secured to said columns in spaced relation, the uppermost plate lying below the upper ends of said columns, and said plates having aligned openings, a-cylinder mounted in said openings, a head piece secured to the upper portion of the cylinder, said head piece resting upon the upper ends of the columns; tension, rods extending upwardly through each column and terminating above the head piece; and means for placing the rods under tension, said means overlying the head and serving to force the head pieces securely against the columns. 1 a

RUDOLF WINTZER.

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