US3621823A - Frictionless rocker arm fulcrum assembly - Google Patents

Frictionless rocker arm fulcrum assembly Download PDF

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Publication number
US3621823A
US3621823A US853349A US3621823DA US3621823A US 3621823 A US3621823 A US 3621823A US 853349 A US853349 A US 853349A US 3621823D A US3621823D A US 3621823DA US 3621823 A US3621823 A US 3621823A
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US
United States
Prior art keywords
rocker arm
fulcrum
valve train
bearing
assembly
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US853349A
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English (en)
Inventor
John Lombardi
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Ford Motor Co
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Ford Motor Co
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Filing date
Publication date
Application filed by Ford Motor Co filed Critical Ford Motor Co
Application granted granted Critical
Publication of US3621823A publication Critical patent/US3621823A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/18—Rocking arms or levers
    • F01L1/181—Centre pivot rocking arms
    • F01L1/182—Centre pivot rocking arms the rocking arm being pivoted about an individual fulcrum, i.e. not about a common shaft
    • F01L1/183—Centre pivot rocking arms the rocking arm being pivoted about an individual fulcrum, i.e. not about a common shaft of the boat type
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/20—Control lever and linkage systems
    • Y10T74/20576—Elements
    • Y10T74/20582—Levers

Definitions

  • a one-piece rocker arm with straight side walls and a semi-cylinder bottom bearing surface is mounted on a fulcrum having cylindrical stub shafts on which are mounted needle bearings and bearing housings; the rocker arm bearing surface has a no-lash engagement with the bottom portion of the bearing housing which rotates with the rocker arm as a unit during a loaded condition of the valve train but rotates relative to the rocker arm during the unloaded -valve train condition due to vibrations of the engine and inertia of the parts to provide even wear of the parts.
  • the fulcrum is provided with an integral sleeve shaft of rectangular or square cross-section which extends through the rocker arm bearing surface and into a slotted recess or groove in the engine cylinder head.
  • a bolt which passes axially through the sleeve shaft secures the fulcrum to the cylinder head.
  • This invention relates, in general, to a valve train for an internal combustion engine. More particularly, it relates to a rocker arm assembly for an over-head valve, push rod type actuated valve train providing minimum frictional resistance to relative rotation between the parts. It will be clear, however, that it is within the scope of the invention to utilize the assembly to be described in con nection with overhead cam shaft type actuated valve train rocker arm assemblies as well.
  • a standard or conventional valve train rocker arm assembly generally is designed to be lubricated adequately at the top valve train speeds it must endure. These top speeds, however, are considerably less than those attained by a so-called race engine valve train, in which the valve train r.p.m. is increased by as much as several thousand. In the latter case, if a conventional valve train rocker arm assembly were used, the lubrication system would be inadequate and considerable heat due to frictional resistance would be generated. Ultimately, parts failure would occur. For example, an unsatisfactorily lubricated valve train assembly produces increase friction and heat as a result of increased load on the bearing surface.
  • a race type engine valve train usually requires a specially constructed or non-production type rocker arm assembly that can withstand the high loads prevalent and also will reduce friction to a minimum so as to reduce the heat and reduce wear of the parts, thereby minimizing fatigue or failure.
  • the conventional engine valve train rocker arm assemblies that use pedestal mounted rocker arms generally have a spherical or part cylindrical fulcrum that provides an essentially large bearing area. This also provides a large area for frictional resistance and heat build-up if not adequately lubricated.
  • Race engines in order to avoid or minimize friction, generally utilize roller bearing assemblies mounted on stub shafts secured to a fulcrum and extending through side wall openings in the rocker arm.
  • the rocker arm in this case, generally has a considerably thicker side wall than that used in conventional street type engine valve trains since the needle bearing assembly generally is pressed into a hole in the side Wall of the rocker arm.
  • race engine type valve trains generally are far more expensive and complex than the conventional street type engine valve trains, and accordingly, would be unsatisfactory from a production standpoint for so-called street engines.
  • a further disadvantage of the pressed needle bearing assembly rocker arm type construction is that during sustained high speed driving, the wear tends to concentrate at the lower portion of the roller bearing assembly; i.e., uneven wear occurs, causing fatigue of one part of the needle bearing assembly while the other portions show essentially no wear whatsoever.
  • the invention provides a high-speed essentially frictionless rocker arm assembly that meets all of the requirements necessary to provide high speed sustained operation without fatigue or failure, and yet is considerably more economical to manufacture and less complex to assemble than the conventional high speed engine valve train.
  • This is because it combines a conventional one piece type rocker arm with a fulcrum assembly constructed according to the invention including a needle bearing assembly. That is, the invention utilizes a needle bearing fulcrum assembly that is easily insertable into a conventional production type rocker arm.
  • the conventional so-called street engine valve train rocker arm assembly can become a high speed race engine valve train rocker assembly simply by replacing the pedestal mounting spherical or part cylindrical fulcrum assembly with one to be described.
  • Another object of the invention is to convert a known type of one piece rocker arm, medium speed, valve train into a high speed valve train by replacing the rocker arm fulcrum with a needle bearing, cylindrical fulcrum type assembly.
  • a still further object of the invention is to provide a valve train rocker arm assembly in which relative rotation betwen the bearing portions is permitted due to engine vibration and inertia forces of the parts, thereby effecting more even wear of the parts and lon er life thereto.
  • FIG. 1 is a cross sectional view of a portion of an internal combustion engine valve train embodying the invention taken on a plane indicated by and viewed in the direction of the arrows 11 of FIG. 2;
  • FIG. 2 is a cross sectional view of the rocker arm assembly of FIG. 1 taken on a plane indicated by and viewed in the direction of the arrows 2-2 of FIG. 3;
  • FIG. 3 is a top view of a portion of a valve train embodying the invention.
  • FIGS. 4a and 4b are cross sectional views corresponding to FIGS. 1 and 2 and illustrating modifications of the invention.
  • FIG. 5 is a cross sectional view similar to FIG. 2
  • FIG. 1 illustrates a portion of the valve train for an internal combustion engine in which over-head valves are used.
  • each spring closed engine valve 10 indicated in phantom, is adapted to be actuated by pivotal movement of a rocker arm 12.
  • the latter is individually or pedestal mounted on a boss 14 projecting from a cylinder head (not shown) of the engine.
  • the opposite end portion of the rocker arm is adapted to be actuated by a push rod 16, also shown in phantom, reciprocated by a conventional tapper means (not shown).
  • Rocker arm 12 in this case is essentially of conventional form and shape. It comprises a stamped or alternately cast one-piece member 12 that has essentially a square U-shape in cross section, as seen in FIG. 2, with essentially straight upstanding side walls 18 joined by a flat bottom wall 20.
  • the side wall portions 18 are continuous from end to end so as to provide rigidity to the construction.
  • the unbroken side walls also laterally locate the rocker arm with respect to the fulcrum assembly and stationary supporting means.
  • Bottom wall 20 is arcuately formed along its longitutudinal length, as best seen in FIG. 1, to provide a valve stem seating and actuating portion 22 at one end and a concave push rod end receiving portion 24 at the opposite end.
  • a lubricating slot 26 cooperates with a lubricant containing bore (not shown) in the push rod for lubrication of the rocker arm mounting means and bearing surfaces in a known manner.
  • Bottom wall 20 also is formed with a concavity providing a semicylindrical internal bearing surface 28.
  • the latter surface has an essentially rectangular aperture 30 that extends arcuately over a major extent of the longitudinal length of cylindrical surface 28 to accommodate pivotal movement of the rocker arm 12 about the stationary supporting means to be described, in a known manner.
  • each rocker arm is adapted to be individually supported upon a cylinder head boss 14.
  • a bolt 32 screwed into the cylinder head as indicated in FIG. 2, receives over it a fulcrum body 34 having an aperture 36 corresponding approximately to the diameter of the bolt.
  • the fulcrum has a stub shaft 38 projecting laterally from each side, and in this case, extending axially essentially into abutting relationship with the side wall 18 of rocker arm 12.
  • the rocker arm thus is laterally or axially located thereby.
  • annular bearing housing 40 Surrounding each of the stub shafts 38 and journaled thereon is an annular bearing housing 40 that is spaced from the shaft and journaled thereon by a needle bearing assembly 42.
  • rocker arm is mounted to rotate with respect to the bearing housings at times and at other times to be non-rotatable therewith depending upon the frictional resistance between, so that during the latter time, both the arm and bearing housings rotate as a unit about the fulcrum. More specifically, when the engine in which the described valve train is installed is Operating so that the cam (not shown) on the cam shaft (also not shown) is forcing the push rod upwardly to load the rocker arm against the lower portion of the bearing housing, the frictional resistance to relative rotation between the bearing housing and rocker arm will be greater at this time than the frictional resistance between the fulcrum shafts and the needle bearing assembly.
  • both the rocker arm and bearing housing rotate as a unit about the fulcrum shafts 38 with a minimum of friction, minimizing heat build-up and parts wear.
  • the push rod will exert essentially no force against the rocker arm at this time.
  • FIGS. 4a and 4b illustrate a modification.
  • the fulcrum 34' has a central hole through which is received the bolt 32 of FIG. 1 to secure the fulcrum to the engine cylinder head.
  • the main body of fulcrum 34' has a depending portion 44 that extends through the rocker arm opening 30 and has a rectangular or square shank shape in cross section. The latter would extend into a slotted recess or groove (not shown) in the cylinder head boss 14 to prevent relative rotation between the fulcrum and cylinder head.
  • FIG. 1 the push rod 16 could be guided by means (not shown) to prevent lateral cocking or rotation of the rocker arm about the cylinder head boss 14.
  • FIGS. 4a and 4b show an alternate arrangement.
  • a still further alternative would be to extend a metal bracket between several, such as four, valves to laterally align the rocker arms. With the use of such a bracket, the depending extension 44 of the fulcrum means 34' could be cylindrical.
  • FIG. 5 illustrates a further modification.
  • each needle bearing assembly 42' includes a cage 54 that has a radially corrugated portion 56 serving as a spacer between the rocker arm side wall 18 and the end of the stub shaft 38'.
  • the spacer thus locates laterally the rocker arm in the same manner that the extended shafts 38 do in FIG. 1.
  • the operation of the FIGS. 4a and 4b and 5 constructions are essentially the same as that already described in connection with the embodiment shown in FIGS. 1 and 2.
  • the invention provides an internal combustion engine valve train rocker arm assembly that minimizes friction between the parts to permit high speed operation with minimum heat build-up due to frictional forces; and also effects an even wear of the parts by permitting relative rotation therebetween during different phases of operation of the valve train, in contrast to conventional constructions. It will also be seen that the invention provides an economically constructed high speed valve train rocker arm assembly, by utilizing a conventional one piece pedestal type rocker arm and replacing the low speed valve train rocker arm fulcrum means with a needle bearing assembly type fulcrum means constructed according to the invention.
  • An engine valve train rocker arm assembly comprising, a one piece hollow rooker arm having essentially a U-shape in cross section with essentially straight side walls and a bottom wall essentially at right angles thereto, the latter formed to provide a semi-cylindrical concave internal bearing surface thereon, an aperture in said surface adapted to receive loosely therethrough a fulcrum supporting means, a fulcrum means receivable within said arm between said side walls and having an aperture adapted to receive said supporting means therein to locate said fulcrum means, and means rotatably mounting said arm semi-clindrical surface on said fulcrum means, said latter means comprising annular housing means rotatably mounted on said fulcrum means within said arm between said side walls and relatively rotatably engageable with said arm at said arm internal bearing surface only so as to effect unitary movement of said arm and housing means at times relative to said fulcrum means and relative rotation between said housing and arm at other times, said unitary or relative rotation varying as

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
US853349A 1969-08-27 1969-08-27 Frictionless rocker arm fulcrum assembly Expired - Lifetime US3621823A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US85334969A 1969-08-27 1969-08-27

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US3621823A true US3621823A (en) 1971-11-23

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Application Number Title Priority Date Filing Date
US853349A Expired - Lifetime US3621823A (en) 1969-08-27 1969-08-27 Frictionless rocker arm fulcrum assembly

Country Status (4)

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US (1) US3621823A (enrdf_load_stackoverflow)
CA (1) CA930266A (enrdf_load_stackoverflow)
DE (1) DE2038381A1 (enrdf_load_stackoverflow)
GB (1) GB1290083A (enrdf_load_stackoverflow)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3870024A (en) * 1974-01-21 1975-03-11 Ralph H Ridgeway Rocker arm stud support device
US3880127A (en) * 1972-12-07 1975-04-29 Eaton Corp Hydraulic valve gear
US3986485A (en) * 1975-08-20 1976-10-19 Lawrence Peska Associates, Inc. Rocker arm shafts
DE3116855A1 (de) * 1980-05-23 1982-02-04 The Torrington Co., 06790 Torrington, Conn. Oszillierendes lager
US4393820A (en) * 1981-05-07 1983-07-19 General Motors Corporation Rolling contact rocker arm and pivot
EP0129961A1 (en) * 1983-05-23 1985-01-02 General Motors Corporation Reciprocating internal combustion engine with valve train means
US4697473A (en) * 1986-08-07 1987-10-06 The Henley Group, Inc. Rocker arm with cam-contacting roller
US4848180A (en) * 1988-09-06 1989-07-18 Henley Manufacturing Corporation Low-friction, boat-type rocker arm
US4858575A (en) * 1988-03-01 1989-08-22 David Fittro Rocker arm bearing assembly
US4878463A (en) * 1987-10-01 1989-11-07 The Torrington Company Needle bearing rocker arm assembly
US4944257A (en) * 1989-09-27 1990-07-31 Henley Manufacturing Holding Company, Inc. Cold-formed rocker arm with bearing flanges and splash plate
US5074261A (en) * 1991-01-14 1991-12-24 The Torrington Company Rocker arm assembly
USRE33870E (en) * 1988-03-01 1992-04-07 The Torrington Company Rocker arm bearing assembly
US5195475A (en) * 1992-05-29 1993-03-23 The Torrington Company Rocker arm assembly
US5297509A (en) * 1993-06-30 1994-03-29 The Torrington Company Rocker arm assembly
US5313916A (en) * 1993-07-30 1994-05-24 The Torrington Company Rocker arm assembly
US5329891A (en) * 1993-08-27 1994-07-19 The Torrington Company Rocker arm assembly
US5433178A (en) * 1994-07-25 1995-07-18 The Torrington Company Rocker arm assembly and method of assembly
US5437209A (en) * 1993-09-30 1995-08-01 The Torrington Company Rocker arm assembly
US5560265A (en) * 1994-07-08 1996-10-01 Miller; James Rocker arm mounting stud
US5730093A (en) * 1996-08-07 1998-03-24 Sandco Automotive Limited Roller rocker arm
US5887474A (en) * 1997-03-20 1999-03-30 E & E Manufacturing Company, Inc. Method for manufacturing a rocker arm
US6612199B2 (en) 2001-01-19 2003-09-02 E & E Manufacturing Company, Inc. Rocker arm assembly
US20040190808A1 (en) * 2003-03-26 2004-09-30 Kikuo Maeda Rolling bearings
US20160376935A1 (en) * 2015-06-26 2016-12-29 Deere & Company Valvetrain for an Engine

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58211515A (ja) * 1982-06-04 1983-12-09 Nissan Motor Co Ltd 弁「隙」間自動調整装置
JPS63183402U (enrdf_load_stackoverflow) * 1987-05-19 1988-11-25
DE102019124549A1 (de) * 2019-08-12 2021-02-18 Schaeffler Technologies AG & Co. KG Brücke für einen Ventiltrieb einer Heavy-Duty-Brennkraftmaschine

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3880127A (en) * 1972-12-07 1975-04-29 Eaton Corp Hydraulic valve gear
US3870024A (en) * 1974-01-21 1975-03-11 Ralph H Ridgeway Rocker arm stud support device
US3986485A (en) * 1975-08-20 1976-10-19 Lawrence Peska Associates, Inc. Rocker arm shafts
DE3116855A1 (de) * 1980-05-23 1982-02-04 The Torrington Co., 06790 Torrington, Conn. Oszillierendes lager
US4314732A (en) * 1980-05-23 1982-02-09 The Torrington Company Oscillating bearing
US4393820A (en) * 1981-05-07 1983-07-19 General Motors Corporation Rolling contact rocker arm and pivot
EP0129961A1 (en) * 1983-05-23 1985-01-02 General Motors Corporation Reciprocating internal combustion engine with valve train means
US4697473A (en) * 1986-08-07 1987-10-06 The Henley Group, Inc. Rocker arm with cam-contacting roller
US4878463A (en) * 1987-10-01 1989-11-07 The Torrington Company Needle bearing rocker arm assembly
US4858575A (en) * 1988-03-01 1989-08-22 David Fittro Rocker arm bearing assembly
USRE33870E (en) * 1988-03-01 1992-04-07 The Torrington Company Rocker arm bearing assembly
US4848180A (en) * 1988-09-06 1989-07-18 Henley Manufacturing Corporation Low-friction, boat-type rocker arm
US4944257A (en) * 1989-09-27 1990-07-31 Henley Manufacturing Holding Company, Inc. Cold-formed rocker arm with bearing flanges and splash plate
US5074261A (en) * 1991-01-14 1991-12-24 The Torrington Company Rocker arm assembly
US5195475A (en) * 1992-05-29 1993-03-23 The Torrington Company Rocker arm assembly
CN1034966C (zh) * 1993-06-30 1997-05-21 托林顿公司 摇臂组件
AU679540B2 (en) * 1993-06-30 1997-07-03 Torrington Company, The Rocker arm assembly
WO1995001499A1 (en) * 1993-06-30 1995-01-12 The Torrington Company Rocker arm assembly
US5297509A (en) * 1993-06-30 1994-03-29 The Torrington Company Rocker arm assembly
US5313916A (en) * 1993-07-30 1994-05-24 The Torrington Company Rocker arm assembly
WO1995006191A1 (en) * 1993-08-27 1995-03-02 The Torrington Company Rocker arm assembly
US5329891A (en) * 1993-08-27 1994-07-19 The Torrington Company Rocker arm assembly
US5437209A (en) * 1993-09-30 1995-08-01 The Torrington Company Rocker arm assembly
US5560265A (en) * 1994-07-08 1996-10-01 Miller; James Rocker arm mounting stud
US5433178A (en) * 1994-07-25 1995-07-18 The Torrington Company Rocker arm assembly and method of assembly
US5730093A (en) * 1996-08-07 1998-03-24 Sandco Automotive Limited Roller rocker arm
US5887474A (en) * 1997-03-20 1999-03-30 E & E Manufacturing Company, Inc. Method for manufacturing a rocker arm
US6612199B2 (en) 2001-01-19 2003-09-02 E & E Manufacturing Company, Inc. Rocker arm assembly
US20040190808A1 (en) * 2003-03-26 2004-09-30 Kikuo Maeda Rolling bearings
US20160376935A1 (en) * 2015-06-26 2016-12-29 Deere & Company Valvetrain for an Engine
US9638073B2 (en) * 2015-06-26 2017-05-02 Deere & Company Valvetrain for an engine

Also Published As

Publication number Publication date
GB1290083A (enrdf_load_stackoverflow) 1972-09-20
DE2038381A1 (de) 1971-03-04
CA930266A (en) 1973-07-17

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