US2818050A - Lubricating system - Google Patents

Description

Dec. 31, 1957 PAPENGUTH 2,818,050

LUBRICATING SYSTEM Filed June 2, 1954 INVENTOR* :91:95 TTOR5EY United States Patent 2,818,050 LUBRICATING SYSTEM" Loren R. Papenguth, Pontiac, Mich., assignor to General Motors-Corporation, Detroit, Mich., a corporation of Delaware Application June 2, 1954; Serial No. 433,990

12 Claims. (Cl. 123-90) reciprocating motion thereto through associated push rodsand valve rockers, the push rod serving also as aconduit for conducting oil from the lifter to the rocker for purposesof lubrication. In prior valve operating linkages of this type is has been customary to supply oil to the rocker from the engine lubricating pump by means separate from the lifter and push rod, and it is one of the objects of this invention to eliminate such separate rocker oil feeding means through the use of the lifter (or conventional tappet) and push rod as the means for delivering oil to the rocker.

While previous proposals have been made to deliver oil from a hydraulic valve lifter to a valve stem or push rod actuated thereby for purposes either of lubrication or cooling, it has been found that use of such means to effect lubrication of a valve operating rocker has heretofore resulted in either an over-supply of oilto the valves at high operating speeds with consequent loss through the valve guides to the engine cylinders, or inability to satisfactorily maintain minimum oil delivery requirements at which novel restricting means are incorporated to ensure maintaining desired oil delivery rates to the rocker throughout the range of intended operating speeds.

The means by which these and other objects of the invention are attained will be fully understood from the following description having reference to the drawing, wherein:

Figure l is a cross-sectional view of a portion of an in ternal combustion engine incorporating a lubricating system in accordance with my invention wherein engine oil' supplied under pressure to a hydraulic valve lifter is deh'vered through a hollow push rod to a cylinder head mounted valve rocker.

Figure 2 is an enlarged sectional view similar to Figure" 1 showing the parts of the hydraulic valve lifter and the adjacent portions of the engine'and push rod ingreater de'-' tail.

Figure 3 is a view similar to Figure 2 showing a modified form of the hydraulic valve lifter.

Referring now in detail to Figures 1 and 2 of the" drawing, the engine shown is of the V-type including a cylinder block and crankcase l in each'side'of which one'or more cylinders 2 are provided audclosed at their upper ends-by 2,818,050 Patented Dec. 31, 1957 a cylinder lie'ad 3. Suitably'journalled in the crankcase is'a camshaft 4' which operatively engages a tappet in the form of a" hydraulicvalve lifter 5 so as to cause it to reciprocate in a suitable bore 6 formed in the crankcase. An engine poppet valve 7, reciprocably mounted in the cylinder head andbiase'd to'its closed position by a valve return spring'S'inconveritional manner, is operatively con-' nected to the lifter 5'by a valve rocker 9 and a hollow push rod 10; The-particular valve rocker' 9 illustrated is in the form of agenerally channel shapedsheet metal stamping havingdownwardly presenting opposite end surfaces 11' and 12 in bearing engagement with the upper ends of the valve" and push rod respectively, and an intermediate upwardlyprese'nting bearing surface 13'journa1ling on a bearing" member 14 fixed to the cylinder head by a stud 15 and nut'16. Be'aringsurfaces'12 and 13 are spherically concavetosocke'tably receive the spherically shaped push roduppe'r en'd'and bearing member 14, respetcively, and the pushrodha's aslidin'g=fit in a guideway 17 therefor extending through the cylinder head. The push rod, being thus'laterally supported andsocketed at its upper end in the'rocker, serves to restrain rotation of the rocker about the axis of'the stud 15" to the extent necessary to maintain the'rocker'end'surface 11 in proper bearing engagement'with the 'stem ofthe valve 7.

Referring to Figure 2, the hydraulic lifter comprises a cup-shapedcylinder' member 20 having a nesting cupshapedpiston? or plunger member 21 telescopically slidablethereinand defining an oil pressure or cushion chamber 22 betweentheir respetcive closed ends. Within the pressure chamber 22'and biasing the plunger outwardly of the cylinder 20 is a'spring 23. The interior of the plunger 21 formsan' oil reservoir chamber 24 for supplying the pressure chamber 22 through acheck valve controlled one- Way passage means shown as a port 25 in the plunger end wall controlled by acheck valve in the form of a ball 26. Acage 'surroundingthe' ball and held in place against the bottom: of the plunger by a spring 23' serves to limit the distance to which the ball may move in opening the port 25; During each lift stroke of the cylinder by the cam 4 oil is trapped in the pressure chamber by the closing of thecheck valve ball against its seat and the plunger is forced to travel upward with the cylinder, carrying with it the push rod seat 27 and the push rod 10, which in turncauses the rocker to fulcrum on thebearing member 14 and-open the valve 7 against its spring 8. During each such cam liftingandvalve opening stroke a small amount of the oil trapped in the pressure chamber 22 escapes around the-plunger, which leakage is termed leak-down andis necessary in order to ensure that thevalve 7 may fully seat on the subsequent return stroke which occurs with continued rotation of the cam 4. Were it not for this leak-down during each lifting stroke, and any of the parts of the valve train lengthened due to increase in temperature, such greater length would hold the engine valve slightly off its seat on the cylinder head.

After the engine valve' returns to its seat on the cylinder head the lifter plunger spring 23 continues to maintain the lifter cylinder 20 in contact with the surface of the cam 4 while holding the plunger 21 in abutment with the push rod to take out all lash in the system. While the lifter cylinder is regaining its engagement with the base circle of the cam the plunger is therefore moved outwardly of the cylinder to compensate for allor substantially all ofits leak-down movement inwardly on the lift stroke. This, results in re-enlarging the cushion chamber 22 and oil flowing thereinto past the then opened check valve 26 from the" reservoir chamber 24. Although a major portion of the leak-down oil escaping around the plunger during the lift" stroke re-enters the reservoir chamber through th'e'pluriger' oil inlet opening or ports 28, in' order to ensure that the reservoir chamber is maintained full at all times one or more oil inlet openings or ports 29 are provided in the side wall of the lifter cylinder to communicate with the plunger ports 28, and these ports 29 in turn are continuously supplied with oil from the engine lubricating system via an external groove 30 on the lifter cylinder periphery registering with a recess 31 in the lifter guide bore which is connected with an engine oil gallery 32 by a passage 33.

Above the reservoir 24, the plunger side walls are counterbored from their open end to form an enlargement 34 in which is slidably fitted the push rod seat 27 which is flanged at its upper end to rest on the open end of the plunger and forms a wall 35 defining the upper limits of the reservoir 24. Centrally of this push rod seat 27 is provided a chamber outlet port 36 connecting at its lower end with the enlarged lower end of the counterbore 34 and a lower end opening 37 in the push rod 10. The reservoir chamber face 38 of this wall 35 forms a seat for a generally plate-like valve 39 which is adapted to abut therewith in restricting oil flow into the push rod through the outlet 36 for delivery to the rocker 9 during operation. The shoulder 40 defining the bottom of the counterbore 34 provides a stop for this valve 39 to limit its movement inwardly of the plunger away from its seating face In order that the valve 39 be prevented from totally closing the port 36 when abutting the face 33 the face 38 is provided with a cylindrical curvature and the opposing face 41 of the valve 39 is made substantially flat.

During operation, while the hydraulic lifter is reciprocating to open and close the engine valve 7 as aforesaid and the reservoir chamber 24 is maintained filled with engine oil under pressure from the gallery 32, the restricting plate-like valve 39 is normally urged by the reservoir oil pressure into abutment with the push rod seating member face 38, restricting oil delivery to the push rod lit and the rocker 9. Due to the inertia forces acting on the plate-like valve 39 during its reciprocation with the lifter, however, it tends to reciprocate within the counterbore 34 between the face 38 and the shoulder 40. By suitably selecting a valve 39 of proper mass weight and selecting a diameter for the outlet 36, however, the engine speed at which the plate-like valve will leave its seat on the face 38 can be predetermined for a given engine oil supply pressure. For example, with an oil pressure of p. s. i., a valve 39 of approximately .030 in. thickness, and a diameter of .060 for the outlet 36, the valve 39 will be found to remain in abutment with the face 38 up through a speed of approximately 1600 R. P. M. for a conventional internal combustion engine of a type presently in use. Also, with the surface 38 having a cylindrical curvature of /2 in. radius under the above conditions it has been found that oil will be supplied to the rocker arm 9 at a rate of .2 to 2 gallons per hour, and using SAE W oil at 80 F. temperature, oil flow to the rocker will be established in approximately 7% minutes after starting the engine. These figures are given merely as representative values, and may be in creased or decreased as desired by changing the outlet opening 36 diameter, valve 39 thickness, oil supply pressure, etc.

In the modified hydraulic valve lifter shown in Figure 3. the construction is substantially the same except that the push rod seat member 270 is provided with a recess 340 for the plate-like valve 390 and extends beyond the latter to carry a washer 400 which takes the place of the shoulder 40 in the Figure 2 construction. This washer may be secured in any suitable manner to the lower end of the push rod seat member 270 as by spinning over the lower end thereof as shown at 271. Also in this modification the plate-like valve 390 is formed barrelshaped, that is its upper and lower faces 391 and 392 have a cylindrical curvature, and the abutment or seat ing face 380 therefor on the member 270 is made sub- 4 stantially flat to prevent total closure of the outlet opening 36.

While only two constructional forms of my invention have been shown for purposes of illustration, it is appreciated that numerous minor changes in the construe tion and arrangement of the parts may be made without departing from the spirit and scope of the invention as defined in the following claims.

I claim:

1. In a lubricating system for an engine or the like including a reciprocatedly actuated tappet having an oil chamber with an inlet opening and an outlet opening, a member externally of the tappet having a bearing surface in fluid communication with said outlet opening, for conducting oil pressure to said inlet opening, a seat in said chamber at the chamber end of one of said openings, and an element movable into and out of abutment with said seat for controlling the oil flow to said bearing surface, said element and seat having their coabuttable surface portions extending only partially about the axis of said one opening whereby said one opening is only partially blocked when said element abuts said seat.

2. In a lubricating system for an engine or the like including a reciprocatedly actuated tappet having an oil chamber with an inlet and an outlet opening, means rcquiring oil delivery from said outlet opening for lubrication, means for conducting oil under pressure to said inlet opening during tappet reciprocation, a seat in said chamber at the chamber end of one of said openings, and an element movable into and out of abutment with said seat for controlling the oil delivery to said first named means, said element and seat having their co-abuttablc surface portions extending only partially about the axis of said one opening whereby said one opening is only partially blocked when said element abuts said seat.

3. In a lubricating sytem for an engine or the like including a reciprocatedly actuated tappet having an oil chamber therein and a seating member externally of and defining an outlet for flow of oil from said chamber, a tappet actuated member seated on said seating member and having an oil conducting passage in registry with said outlet, means for introducing oil under pressure into said chamber for flow through said outlet and passage, a seat in said chamber at the chamber end of said outlet, and an element movable into and out of abutment with said seat for controlling the rate of said oil flow, one of said element and seat having its abuttable surface curved relative to the abuttable surface of the other to preclude their abutting engagement extending fully about the axis of said outlet.

4. In a lubricating system for an engine or the like having a bearing surface, a reciprocatedly actuated tappet having an internal chamber supplied with engine oil under pressure and defined in part by a wall, said wall having an aperture communicating with said bearing sur face, and a plate movable within said chamber and nor mally urged against said wall by the engine oil pressure to restrict the outward flow of oil through said aperture, said plate and wall having their oppositely facing surfaces in only partially abuttable relation about the periphery of the entrance to said aperture so as to prevent the plate from completely closing the aperture at any time.

5. In a lubricating system for an engine or the like including a reciprocatedly actuated tappet having an internal chamber supplied with oil under pressure, mechanism having bearing surfaces lubricated with oil from said chamber including a rocker and a hollow push rod drivingly connecting said rocker to the tappet and constituting an oil conductor between said chamber and said bearing surfaces, a seat for said push rod on the tappet, said seat having an aperture extending into said chamber and communicating with the interior of said push rod, said chamber being defined about the entrance to said aperture by a face of substantial width, and a valve having a face adapted to abut said entrance defining face and movable into and out of abutment therewith, one of said faces being curved about a single axis transverse thereto and the other being substantially flat.

6. The invention defined in claim 5, wherein said curved face is on the valve.

7. The invention defined in claim 5, wherein a shoulder is provided in said chamber in spaced relation from said entrance defining face and limits movement of the valve away from said entrance defining face.

8. In a lubricating system for an engine or the like having a cylinder head, a valve actuating rocker mounted in the head, driving means for said rocker including a hydraulic valve lifter, said valve lifter comprising a cylinder member and a hollow piston member slidable there in having communicating oil inlet ports in their side walls, said cylinder member having one end closed and defining an oil cushion chamber between said end and the piston member, one-way check valve means providing for flow of oil into said cushion chamber from the interior of the piston, said piston having an oil outlet port connected for oil delivery to the rocker, means communicating with said cylinder for conducting oil under pressure to said cylinder port for delivery to the interior of the piston through said piston oil inlet port, and a valve within said piston and movable relative thereto into flow restricting relation with said outlet port in response to oil pressure within the cylinder and movable substantially out of flow restricting relation against said pressure in response to inertia forces acting on the valve at a predetermined engine speed.

9. In a lubricating system for a cylinder head mounted valve operating rocker, a hydraulic valve lifter having an oil pressure chamber and oil supply chamber therefor having an oil inlet and an oil outlet, means externally of said lifter for conducting oil under pressure to said inlet and from said outlet to said rocker, said lifter having a mechanical connection with said rocker including a wall surrounding the chamber end of said outlet, a generally plate-shaped valve adapted to abut said wall and movable out of abutment therewith to respectively increase and decrease the restriction to flow of oil to said outlet within the chamber, said wall and valve having their co-abutting surfaces only partially circumferentially coextensive with each other about the chamber end of said outlet whereby when said valve is in abutment with said wall the chamber end of said outlet is only partially closed.

10. In a lubricating system for a cylinder head mounted valve operating rocker, a cylinder head, a rocker mounted thereon having a bearing surface, a push rod having one end drivably connected to the rocker, said rocker and push rod having connecting oil passageways for conducting oil to said bearing surface, a hydraulic valve lifter drivably connected to the other end of said push rod, said lifter including slidably interfitted cupshaped cylinder and plunger members having their closed and open ends in corresponding relation and defining an oil cushion chamber in series thrust transmitting relation between their closed ends and a reservoir chamber for said cushion chamber, means for conducting make-up oil under pressure to said reservoir chamber from a source externally of said lifter, spring means urging the plunger member outwardly of the cylinder member, check valve means between said members providing for one-way flow of oil to said cushion chamber from said reservoir chamber, a push rod seating member resting on the plunger member open end and having a central aperture connecting said reservoir chamber to said push rod passageway, said push rod seat having a substantially flat surface defining said reservoir chamber about said aperture, a generally plate-like valve slidably guided by the laterally defining walls of said reservoir chamber for movement into and out of abutment with said push rod seating member flat surface to variably restrict oil flow out of said chamber through said aperture, and stop means between said plate-like valve and said check valve means to limit aperture restriction decreasing movements of said plate valve, said plate-like valve having its surface abuttable with said flat surface curved about a single axis transverse to said aperture to preclude a total closure of the reservoir chamber end of said aperture.

11. A hydraulic valve lifter constituting a lubricant conductor between a valve operator and a source of lubricant under pressure, comprising cooperating cylinder and plunger members defining an oil cushion chamber and an oil reservoir chamber therefor, passage means for conducting oil from the reservoir to the cushion chamber, a pressure oil supply inlet to the reservoir chamber and an oil delivery outlet leading from the reservoir chamber adapted to be connected to said valve operator, said reservoir chamber being defined inwardly adjacent said outlet by a valve seating surface, and a valve adapted to abut said seating surface and to move away thereform within said reservoir chamber, and stop means in operatively fixed relation to said plunger member between said passage means and said outlet to limit movement of said valve away from said aperture.

12. A hydraulic valve lifter comprising a cylinder adapted to be guided for reciprocatory movement, a hollow plunger slidably fitting said cylinder and cooperating therewith to define an oil cushion chamber in endwise thrust transmitting relation therebet-ween, passage means connecting said chamber with the interior of the plunger and other passage means for conducting oil under pressure from a point externally of the lifter to the interior of the plunger, said plunger having a wall provided with an outlet leading externally of the lifter, and a valve controlling the flow of oil through said outlet, said valve being movable toward and away from said wall in response to the oil pressure acting on said valve within the plunger and the inertia forces on said valve incident to its reciprocatory movement during reciprocation of the plunger and cylinder, and means carried by the plunger and restricting movement of the valve away from said wall, said valve and wall having cooperating abuttable surfaces, one of said surfaces having a substantial singleaxis curvature relative to the other to ensure against total closure of said outlet at its end interiorly of the plunger.

References Cited in the file of this patent UNITED STATES PATENTS 1,930,568 Short Oct. 17, 1933 2,645,215 Moser July 14, 1953 FOREIGN PATENTS 481,811 Great Britain Mar. 18, 1938 536,674 Great Britain May 22, 1941 830,433 Germany Feb. 4, 1952

Images