US20040216710A1 - Internal combustion engine - Google Patents

Internal combustion engine Download PDF

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Publication number
US20040216710A1
US20040216710A1 US10/833,682 US83368204A US2004216710A1 US 20040216710 A1 US20040216710 A1 US 20040216710A1 US 83368204 A US83368204 A US 83368204A US 2004216710 A1 US2004216710 A1 US 2004216710A1
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United States
Prior art keywords
camshaft
engine
oil
cover
front cover
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.)
Abandoned
Application number
US10/833,682
Inventor
Richard Owen
Timothy Lancefield
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mechadyne PLC
Original Assignee
Mechadyne PLC
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mechadyne PLC filed Critical Mechadyne PLC
Assigned to MECHADYNE PLC reassignment MECHADYNE PLC ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LANCEFIELD, TIMOTHY MARK, OWEN, RICHARD ALWYN
Publication of US20040216710A1 publication Critical patent/US20040216710A1/en
Abandoned 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
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/047—Camshafts
    • 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
    • F01L1/02—Valve drive
    • 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
    • F01L1/02—Valve drive
    • F01L1/022—Chain drive
    • 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
    • F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
    • 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
    • F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
    • F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
    • F01L1/3442—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear using hydraulic chambers with variable volume to transmit the rotating force
    • 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
    • F01L1/46—Component parts, details, or accessories, not provided for in preceding subgroups

Definitions

  • the present invention relates to an internal combustion engine.
  • variable valve actuation mechanisms are known from the prior art each having its own advantages and disadvantages.
  • the majority of these mechanisms use oil pressure to control their operation via a control valve to which the oil is supplied by way of passages in the camshaft and/or the cylinder head.
  • a problem that is encountered with this approach is that the rate at which oil can be supplied to the control valve is restricted by the size of the passages.
  • a still further disadvantage is that the requirement for oil passages in the engine block, cylinder head and valve train can make it difficult to retro-fit a variable valve actuation mechanism into an existing engine.
  • U.S. Pat. No. 6,247,436 discloses an internal combustion engine having a crankshaft and a camshaft the ends of which project from a front end of the engine, a hydraulically operable variable valve actuation mechanism at the front end of the engine for driving the camshaft, an engine driven oil pump located at the front end of the engine and drive means located at the front end of the engine for transmitting torque from the crankshaft to the variable valve actuation mechanism.
  • a front cover overlying the variable valve actuation mechanism comprises oil supply passages that are directly connected to the variable valve actuation mechanism, to enable the resistance to oil flow of the hydraulic circuit connecting the engine drive oil pump to the variable valve actuation mechanism to be reduced.
  • U.S. patent application Ser. No. 2002/0029910 also shows a camshaft that is fitted with a vane-type phaser, i.e. a phase changing mechanism, to which oil is supplied through a cover fitted to the front of the engine.
  • a vane-type phaser i.e. a phase changing mechanism
  • a spigot projecting from the engine front cover fits inside part of the phaser or the camshaft to supply oil to the phaser.
  • Such a configuration necessarily increases the diameter of at least part of the phaser and in the case of the phaser described in U.S. patent application Ser. No. 2002/0029910, this spigots extends most of the way into the phaser and forces the diameter of the entire assembly to be increased.
  • the present invention provides an engine having a camshaft formed with an oil passage, a cover fitted to the front of the engine and overlying the front end of the camshaft, and an oil supply line formed in the engine front cover, wherein the camshaft is formed with an axially projecting extension that is rotatably and sealingly received in an opening formed in the front cover to enable the oil passage in the camshaft to communicate with the oil supply line in the engine cover.
  • the camshaft is extended forwards to project into the front cover instead of there being a spigot on the front cover that projects into the camshaft.
  • the desired fluid communication between the oil supply line of the front cover and the oil passage of the camshaft is achieved without the need to increase the diameter of any part of the camshaft or the phaser.
  • the accompanying drawing shows a camshaft 14 coupled to a drive pulley 16 through a vane-type phaser having vanes 18 and vane cavities 20 .
  • the pulley 16 has inwardly extending vanes 18 each of which extends into a respective arcuate recess defined by the camshaft 14 and divides the recess into two variable volume cavities 20 or working chambers. Torque is transmitted from the pulley 16 to the camshaft 16 through oil filling the cavities 20 . When no oil can flow into or out of the cavities, the pulley 16 and the camshaft 14 are hydraulically locked to one another.
  • FIG. 4 of the latter patent application shows a similar section to that shown in the accompanying drawing. For this reason, it is not deemed necessary to describe the camshaft 14 nor the vane-type phaser in greater detail within the present context. It is also not necessary to dwell on the construction and operation of a vane-type phaser because it is not fundamental to the present invention.
  • the invention is concerned with the manner of introducing oil into a rotating camshaft rather than with the function served by the oil after it has been so introduced.
  • the engine of the present invention is fitted with a front cover 22 having various oil supply lines 24 that communicate through a control valve (not shown) with main oil supply and return galleries that lead to the engine oil pump.
  • the supply lines 24 in turn communicate with various passages 26 that lead to different ones of the vane cavities 20 .
  • a suitable engine front cover is described fully in U.S. Pat. No. 6,247,436, which is imported herein by reference and for this reason it is not deemed necessary for it to be described in detail within the present context.
  • the camshaft 14 and the front cover 22 shown in the accompanying drawings differ from the prior art designs in that the camshaft 14 has an end that projects axially beyond the phaser and is received in an opening in the front cover 12 .
  • the end of the camshaft 14 can rotate within the front cover 22 and continuous communication between the passages 26 and the supply lines 24 is achieved through radial bores 32 in the camshaft and circumferentially extending grooves 34 in the wall of the cylindrical opening.
  • the shaft is further provided with seals 30 that seal against the lands defined between the grooves in the opening.
  • the invention permits a phaser to be contained within a pulley having the same size as a conventional camshaft drive pulley and no modification is required to the engine block to provide an adequate oil supply to the phaser other than to fit a front cover to the engine block, as has been proposed previously.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve Device For Special Equipments (AREA)
  • Lubrication Of Internal Combustion Engines (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)

Abstract

An engine is described having a camshaft 14 formed with an oil passage 26, a cover 22 fitted to the front of the engine and overlying the front end of the camshaft 14, and an oil supply line 24 formed in the engine front cover. The camshaft 14 is formed with an axially projecting extension that is rotatably and sealingly received in an opening formed in the front cover 22 to enable the oil passage 26 in the camshaft to communicate with the oil supply line 24 in the engine cover 22.

Description

  • The present invention relates to an internal combustion engine. [0001]
  • The optimum angles at which the inlet and exhaust valves of an internal combustion engine should open and close, both in relation to one another and in relation to the engine crankshaft, and optimum valve lift all vary with the engine speed and load conditions. In an engine with fixed camshafts, a compromise setting must be adopted in which the different performance parameters are traded off one against the other. [0002]
  • To achieve performance improvements over a range of engine speeds and loads, it has already been proposed to vary the cam phase, duration, lift or a combination of these parameters in relation to the crankshaft by the introduction of variable valve actuation mechanisms. [0003]
  • Several variable valve actuation mechanisms are known from the prior art each having its own advantages and disadvantages. The majority of these mechanisms use oil pressure to control their operation via a control valve to which the oil is supplied by way of passages in the camshaft and/or the cylinder head. A problem that is encountered with this approach is that the rate at which oil can be supplied to the control valve is restricted by the size of the passages. Furthermore, there will be a drop in oil pressure due to the cylinder head being far removed from the oil pump in the case of many engines. Consequently, the variable valve actuation mechanism can only respond slowly when a change to its current setting is required. [0004]
  • A still further disadvantage is that the requirement for oil passages in the engine block, cylinder head and valve train can make it difficult to retro-fit a variable valve actuation mechanism into an existing engine. [0005]
  • U.S. Pat. No. 6,247,436 discloses an internal combustion engine having a crankshaft and a camshaft the ends of which project from a front end of the engine, a hydraulically operable variable valve actuation mechanism at the front end of the engine for driving the camshaft, an engine driven oil pump located at the front end of the engine and drive means located at the front end of the engine for transmitting torque from the crankshaft to the variable valve actuation mechanism. A front cover overlying the variable valve actuation mechanism comprises oil supply passages that are directly connected to the variable valve actuation mechanism, to enable the resistance to oil flow of the hydraulic circuit connecting the engine drive oil pump to the variable valve actuation mechanism to be reduced. [0006]
  • U.S. patent application Ser. No. 2002/0029910 also shows a camshaft that is fitted with a vane-type phaser, i.e. a phase changing mechanism, to which oil is supplied through a cover fitted to the front of the engine. [0007]
  • In both these prior art proposals, a spigot projecting from the engine front cover fits inside part of the phaser or the camshaft to supply oil to the phaser. Such a configuration necessarily increases the diameter of at least part of the phaser and in the case of the phaser described in U.S. patent application Ser. No. 2002/0029910, this spigots extends most of the way into the phaser and forces the diameter of the entire assembly to be increased. [0008]
  • With a view to mitigating this problem, the present invention provides an engine having a camshaft formed with an oil passage, a cover fitted to the front of the engine and overlying the front end of the camshaft, and an oil supply line formed in the engine front cover, wherein the camshaft is formed with an axially projecting extension that is rotatably and sealingly received in an opening formed in the front cover to enable the oil passage in the camshaft to communicate with the oil supply line in the engine cover. [0009]
  • In the invention, the camshaft is extended forwards to project into the front cover instead of there being a spigot on the front cover that projects into the camshaft. In this way, the desired fluid communication between the oil supply line of the front cover and the oil passage of the camshaft is achieved without the need to increase the diameter of any part of the camshaft or the phaser. [0010]
  • The invention will now be described further, by way of example, with reference to the accompanying drawing, which is a partial section through a camshaft fitted with a vane-type phaser.[0011]
  • The accompanying drawing shows a [0012] camshaft 14 coupled to a drive pulley 16 through a vane-type phaser having vanes 18 and vane cavities 20. The pulley 16 has inwardly extending vanes 18 each of which extends into a respective arcuate recess defined by the camshaft 14 and divides the recess into two variable volume cavities 20 or working chambers. Torque is transmitted from the pulley 16 to the camshaft 16 through oil filling the cavities 20. When no oil can flow into or out of the cavities, the pulley 16 and the camshaft 14 are hydraulically locked to one another. To vary the angular position of the pulley 14 relative to the camshaft and thereby effect a change in the phase of the camshaft 14 relative to the engine crankshaft that drives the pulley 16, oil is admitted into the cavity on one side of a vane while at the same time allowing oil to escape from the cavity on the opposite side of the vane.
  • A camshaft having this type of phaser is more fully described in U.S. Pat. No. 2002/0059910, which is imported herein by reference. FIG. 4 of the latter patent application shows a similar section to that shown in the accompanying drawing. For this reason, it is not deemed necessary to describe the [0013] camshaft 14 nor the vane-type phaser in greater detail within the present context. It is also not necessary to dwell on the construction and operation of a vane-type phaser because it is not fundamental to the present invention. The invention is concerned with the manner of introducing oil into a rotating camshaft rather than with the function served by the oil after it has been so introduced.
  • The engine of the present invention is fitted with a [0014] front cover 22 having various oil supply lines 24 that communicate through a control valve (not shown) with main oil supply and return galleries that lead to the engine oil pump. The supply lines 24 in turn communicate with various passages 26 that lead to different ones of the vane cavities 20. A suitable engine front cover is described fully in U.S. Pat. No. 6,247,436, which is imported herein by reference and for this reason it is not deemed necessary for it to be described in detail within the present context.
  • The [0015] camshaft 14 and the front cover 22 shown in the accompanying drawings differ from the prior art designs in that the camshaft 14 has an end that projects axially beyond the phaser and is received in an opening in the front cover 12. The end of the camshaft 14 can rotate within the front cover 22 and continuous communication between the passages 26 and the supply lines 24 is achieved through radial bores 32 in the camshaft and circumferentially extending grooves 34 in the wall of the cylindrical opening. The shaft is further provided with seals 30 that seal against the lands defined between the grooves in the opening.
  • Because no part of the [0016] cover 22 extends into the camshaft, the diameter of the camshaft 14 and of the phaser need not be increased to allow a rotary hydraulic connection to be achieved between the camshaft and the engine front cover.
  • In this way, the invention permits a phaser to be contained within a pulley having the same size as a conventional camshaft drive pulley and no modification is required to the engine block to provide an adequate oil supply to the phaser other than to fit a front cover to the engine block, as has been proposed previously. [0017]

Claims (3)

1. An engine having a camshaft formed with an oil passage, a cover fitted to the front of the engine and overlying the front end of the camshaft, and an oil supply line formed in the engine front cover, wherein the camshaft is formed with an axially projecting extension that is rotatably and sealingly received in an opening formed in the front cover to enable the oil passage in the camshaft to communicate with the oil supply line in the engine cover.
2. An engine as claimed in claim 1, wherein the camshaft is fitted with a variable valve timing mechanism actuated by means of the oil in the oil passage.
3. An engine as claimed in claim 2, wherein the variable valve timing mechanism is a vane-type phaser.
US10/833,682 2003-04-29 2004-04-27 Internal combustion engine Abandoned US20040216710A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0309710.2 2003-04-29
GB0309710A GB2401150A (en) 2003-04-29 2003-04-29 I.c. engine camshaft oil supply arrangement

Publications (1)

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US20040216710A1 true US20040216710A1 (en) 2004-11-04

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EP (1) EP1473443A3 (en)
GB (1) GB2401150A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9068482B2 (en) 2011-01-14 2015-06-30 Mechadyne International Limited Spool valve

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GB2445570B (en) * 2007-01-09 2011-04-06 Mechadyne Plc Rotary hydraulic coupling
US8028666B2 (en) 2008-03-12 2011-10-04 GM Global Technology Operations LLC Concentric camshaft with bearing sleeve and method of debris removal
US7849829B2 (en) 2008-03-12 2010-12-14 Gm Global Technology Operations, Inc. Concentric camshaft with independent bearing surface for floating lobes
US7866293B2 (en) 2008-03-12 2011-01-11 GM Global Technology Operations LLC Concentric camshaft with improved torque resistance
US7966983B2 (en) 2008-04-10 2011-06-28 GM Global Technology Operations LLC Concentric camshaft with varying wall geometry and method of assembly
CN101368492B (en) * 2008-06-13 2010-07-07 奇瑞汽车股份有限公司 Camshaft of car engine
US8215274B2 (en) 2008-06-18 2012-07-10 GM Global Technology Operations LLC Hydraulic control system for engine cam phasing
CN102434238A (en) * 2011-11-23 2012-05-02 重庆长安汽车股份有限公司 Engine cam shaft matched with phaser
CN109869210B (en) * 2017-12-01 2021-02-12 北汽福田汽车股份有限公司 Camshaft end connecting device, camshaft, engine and vehicle

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US6269785B1 (en) * 1998-01-29 2001-08-07 Denso Corporation Variable valve timing mechanism

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US5924395A (en) * 1997-02-14 1999-07-20 Toyota Jidosha Kabushiki Kaisha System for regulating valve timing of internal combustion engine
US6269785B1 (en) * 1998-01-29 2001-08-07 Denso Corporation Variable valve timing mechanism

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9068482B2 (en) 2011-01-14 2015-06-30 Mechadyne International Limited Spool valve

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Publication number Publication date
EP1473443A2 (en) 2004-11-03
EP1473443A3 (en) 2008-01-30
GB2401150A (en) 2004-11-03

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AS Assignment

Owner name: MECHADYNE PLC, UNITED KINGDOM

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:OWEN, RICHARD ALWYN;LANCEFIELD, TIMOTHY MARK;REEL/FRAME:014668/0587

Effective date: 20040426

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION