US2280753A

US2280753A - Housing and support for engine camshafts

Info

Publication number: US2280753A
Application number: US310511A
Authority: US
Inventors: Essl Max
Original assignee: Baldwin Locomotive Works
Current assignee: Baldwin Locomotive Works
Priority date: 1939-12-22
Filing date: 1939-12-22
Publication date: 1942-04-21
Anticipated expiration: 1959-04-21

Description

A rilz'l, 1942. S L 2,280,753

HOUSING AND SUPPORT FOR ENGINE CAMSHAFTS Filed Dec. 22,- 1939 2 Sheets-Sheet l I INVENTOR Max E351.

ATTORNEY April 21, 1942. M. ESSL 2,280,753

HOUSING AND SUPPORT FOR ENGINE CAMSHAFTS Filed Dec. 22, 1959 2 Sheets-Sheet 2 Patented Apr. 21, 1942 UNITED STATES PATENT OFFICE HOUSING AND SUPPORT FOR ENGINE CAllISHAFTS Application December 22, 1939, Serial No. 310,511

4 Claims.

This invention relates generally to internal combustion engines and more particularly to an improved arrangement for supporting and. housing a camshaft and the valve push rod guides operated by the camshaft.

While my invention relates broadly to internal combustion engines, it is especially applicable to Diesel engines of relatively large horsepower such as are used in locomotives, municipal lighting plants, pipe line pumping equipment, and other fields wherein engines run under large loads continuously for days or months at a time. Service of the foregoing kind requires an engine of extreme ruggedness and dependability combined with low initial investment as well as low cost of operation and maintenance.

Considerable expense and complications have heretofore been incident to prior constructions and arrangements used for supporting and housing the camshaft and the guides for the valve operating push rods. Hence one object of my invention is to provide an improved arrangement for supporting and housing the camshaft and push rod guides whereby the camshaft bearings can be easily, quickly and accurately secured in proper relation to the camshaft without sacrificing either ruggedness or the precision qualities necessary to apparatus of this kind.

A further object is to provide an improved arrangement that is relatively simple and economical in construction, operation and maintenance and in which the parts are highly accessible and may be readily assembled or removed and replaced with minimum effort and time.

Other objects and advantages will be more apparent to those skilled in the art from the following description of the accompanying drawings in which:

Fig. 1 is a fragmentary perspective view of an engine frame showing one element of my improved bracket for supporting the camshaft bearing and the push rod guides;

Fig. 2 is a plan viewtaken substantially on the line 2-2 of Fig. 4;

Fig. 3 is a vertical transverse section taken substantially on the line 33 of Fig. 4; and

Fig. 4 is a vertical longitudinal section taken substantially on the line 4-4 of Fig. 3 with certain parts shown in elevation for sake of clarity.

In the particular embodiment of the invention as shown herein for purposes of illustration, there is provided a suitable engine frame I which specifically is of the welded built-up plate type having usual openings 2 for cast cylinder liners (not shown) arranged in a straight line with 5,.

each other; A longitudinal crankshaft (not shown) is supported in usual crankshaft bearings. All the usual engine parts are omitted from Fig. l for the sake of clarity inasmuch as my invention is particularly directed to the improved camshaft housing, bearing and push rod guide arrangement. To this end there is formed on the frame side 3 a camshaft housing 4 preferably substantially square when viewed in crosssection. One of the essential cooperative features of this housing is the provision of a fiat horizontally extending upper supporting surface 5 which, by reason of its simplicity, may be readily machined not only throughout its entire length but also easily machined to a definite height above the camshaft axis thereby allowing my improved camshaft bearing and push rod guide brackets as hereafter described to be quickly and accurately placed in position with minimum attention and effort in aligning the bearings. Also by virtue of the relatively simple straight top 5 as well as the longitudinal straight bottom 6 and inner and outer sides I and 8, the housing can be made of plate metal suitably welded together at its corners or the same may be readily formed as a simple casting as shown herein.

The lower portion 9 of the engine frame flares downwardly as shown in Fig. 3 and hence the inner housing wall 8 is shaped in a complementary manner as shown. Preferably, this inher wall 8 is spaced slightly from the engine frame while the inner edges of the upper and lower walls are provided with suitable ribs or projections l0 extending continuously throughout the length of the brackets and secured to the engine frame by welded seams at the outer corners. While the housing in its completely as sembled relation to the engine frame constitutes a continuously integral member, it is preferably made in a plurality of sections welded together at transverse joints l2. The outer wall I is provided with openings I3 of substantial 1ongitudinal extent and covered with plates l3 thereby permitting removal of the camshaft laterally through these openings or, if desired, the camshaft may be removed axially from the housing through a suitable end opening I 4. To remove the camshaft laterally through the side openings, it may be necessary in some instances to have the camshaft separable at some convenient point intermediate its ends. A series of vertical openings l5 disposed in longitudinal alignment with each other are formed in the top wall 5, one opening being provided adjacent each cylinder.

One end of each of these openings is preferably slightly enlarged as at [6 to receive a single bearing projecting downwardly from each of the brackets to be described.

As shown in Fig. 4, there are a series of identical brackets l1, one for each cylinder and hence it will suffice to describe only one of these brackets. The bracket has a base flange I8 machined on its lower surface so as to rest upon the upper surface of the housing and is secured thereto by a series of bolts I9. Projecting upwardly from and offset to one end of the base I8 is a substantial upward projection 49 having a plurality of vertical guide bores 20, 2| and 22. These bores as shown in Fig. 4 also project downwardly below the top surface 5. The bores and 22 are preferably used to slidably guide cam follower cross-heads 23 having usual rollers at their lower ends for engaging the cam lobes of a camshaft 24. The center bore 2| has a similar crosshead 25 actuated-by the camshaft to operate a suitable usual Diesel engine fuel pump 26. This fuel'pump is secured to the projection I9 by cap bolts 26, Fig. 3, to form a self-contained unit with the bracket unit. The details of construction of the pump do not constitute a part of my present invention and hence further description is not deemed necessary. The two roller guides 23 actuate usual engine inlet and exhaust valves through push rods 2'! and 21', while stationary sleeves 28 enclosing the push rods are secured to the bracket by bolts 29.

Projecting downwardly from one end of the base It preferably adjacent the bore 29 is a single camshaft bearing 30 provided with a lower bearing cap 3! which is removably held in position by bolts 32 extending down through the projection l9 and threaded into the bearing cap. It will be noted that the bracket, or the camshaft as the case may be, overhangs the single bearing 30 by a distance substantially equal to the length of the bracket. In the specific disclosure hereof the foregoing extent of overhang is preferably entirely to one side of the bearing. Regardless of the nature of the overhang, it has the desirable result of allowing the successive bracket bearings to be in sufficient alignment with each other without requiring the entire length of the bracket to have absolute parallelism with the camshaft axis. In other words, the ends of the brackets remote from the bearings 30 may have a larger tolerance of lateral displacement than if camshaft bearings were provided at each end of each bracket because in this latter case each bearin would have to be inalignment with the camshaft whereas with a single bearing the usual bearing clearance permits some degree of lateral an ularity of the brackets while still permitting sufiicient operative alignment of the bearing and camshaft axes.

A maximum height of the oil level in the camshaft housing is conveniently and simply obtained by providing an overflow port 33 formed in a boss 34 which extends through a suitable opening in the frame wall 3 and is welded thereto at its inner side.

A very desirable result of my improved combination is that minimum time and effort are required to position accurately the bracket bearings in their operative relation to the camshaft 24. This is accomplished by the fact that the under surface of base flange l8 may be easily machined and thereafter each bracket may be placed in a suitable fixture for machining its bearing 30 while accurately maintaining its axis a uniform distance from the under surface of flanges I8. Hence these brackets, accurately machined in a simple manner so as to be uniform, can now be placed directly on the horizontal supporting surface 5 thereby insuring a uniform vertical positioning of the bearings so that it is then only necessary to secure the bearing caps 31 in position around either the camshaft 24 01' a suitable camshaft mandrel, whereupon bolts !9 are then secured in position.

The foregoing structure, mode of operation and results not only eliminate what has heretofore been an extremely costly and tedious operation of scraping the camshaft bearings in order to secure adequate alignment thereof but in addition my improved combination and the component elements are compact, single and economical in construction as well as presenting a clean appearance combined with a high degree of ruggedness. Also, the parts are readily accessible for inspection and repair and all parts are so related that they have a highly cooperative relation so as to insure maximum usefulness for each component element but without in any way sacrificing the precision qualities of such apparatu's.

It will of course be understood that various changes in details of construction and arrangement of parts may be made by those skilled in the art without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. The combination with an engine frame of the type having a multiplicity of cylinders in line with each other, of means providing a longitudinally extending horizontal supporting surface provided with a plurality of openings, a camshaft disposed to one side of said supporting surface, brackets removably supported on and secured to said horizontal supporting surface, and each bracket having as a self-contained part thereof a single camshaft bearing which extends through one of said openings.

2. The combination with an engine frame of the type having a multiplicity of cylinders in line with each other, of means providing a supporting surface on said engine, said surface having a plurality of openings therethrough, a camshaft disposed to one side of said surface, removable brackets mounted upon and secured to said supporting surface and having a plurality of push rod guide bores whose axes are substantially normal to the plane of said supporting surface, and each bracket having as a self-contained part thereof a single camshaft bearing which extends through one of said openings.

3. The combination with an engine frame of the type having a multiplicity of cylinders in line with each other, of a camshaft, means for supporting the same including a bracket and a frame surface operative by itself to support the bracket in vertically spaced relation to the camshaft axis, said frame surface having openings respectively for said brackets, each of said brackets having as a self-contained part thereof a single camshaft hearing which extends through said openings, and each of said brackets, also having a plurality of cam follower guide bores which extends away from said openings in a direction opposite to said bearings.

4. The combination with an engine frame of the type having a multiplicity of cylinders in line with each other, of means forming a substantially box shape camshaft housing extending continuously in a longitudinal direction along one side of said engine frame, said housing having a horizontal upper surface provided with a series of vertical openings therein placed in longitudinal alignment with each other, a plurality of brackets one for each of said vertical openings having a base mounted on said horizontal supporting surface so that the brackets respectively lie over said vertical openings, each of said brackets having as a self-contained part thereof a bearing projecting downwardly through said vertical openings for journalling a camshaft disposed within said housing, a plurality of bores formed in said bracket, and means for removably securing the base of said bracket to said supporting surface.

MAY ESSL.