GB2327482A - Composite camshaft with internal variable cam timing mechanism - Google Patents

Composite camshaft with internal variable cam timing mechanism Download PDF

Info

Publication number
GB2327482A
GB2327482A GB9811986A GB9811986A GB2327482A GB 2327482 A GB2327482 A GB 2327482A GB 9811986 A GB9811986 A GB 9811986A GB 9811986 A GB9811986 A GB 9811986A GB 2327482 A GB2327482 A GB 2327482A
Authority
GB
United Kingdom
Prior art keywords
drive collar
tube
piston
assembly
piston 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.)
Withdrawn
Application number
GB9811986A
Other versions
GB9811986D0 (en
Inventor
Jr Louis V Orsini
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.)
Timken US LLC
Original Assignee
Torrington Co
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 Torrington Co filed Critical Torrington Co
Publication of GB9811986D0 publication Critical patent/GB9811986D0/en
Publication of GB2327482A publication Critical patent/GB2327482A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H53/00—Cams ; Non-rotary cams; or cam-followers, e.g. rollers for gearing mechanisms
    • F16H53/02—Single-track cams for single-revolution cycles; Camshafts with such cams
    • F16H53/04—Adjustable cams
    • 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
    • F01L1/34—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
    • F01L1/34403—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 helically teethed sleeve or gear moving axially between crankshaft and camshaft
    • 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
    • F01L2001/0471—Assembled camshafts
    • F01L2001/0473—Composite camshafts, e.g. with cams or cam sleeve being able to move relative to the inner camshaft or a cam adjusting rod

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Valve Device For Special Equipments (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Gears, Cams (AREA)

Abstract

A composite camshaft having variable cam timing includes a sprocket (5) and shaft (10) assembly, a tube (20) and cam element (25) assembly, a mechanism (40), axially movable relative to the tube and shaft, for causing the tube and cam element assembly to rotate relative to the sprocket and shaft assembly to vary cam timing, and provision for axially displacing the axially movable mechanism. The axially movable mechanism (40) is axially displaced by a pressurised fluid admitted to the interior 10 of the tube through a port (22) on one side of the mechanism, and the mechanism is biassed to its non-displaced position preferably by a spring (30) on an opposite side of the mechanism.

Description

2327482 COMPOSITE CAMSHAFT WITH INTERNALLY VARIABLE CAM TIMING This
invention combustion engine relates generally to internal camshafts and more particularly to composite camshafts with internally variable cam timing.
Internal combustion engines require different valve timing at high and low speeds in order to operate at optimum efficiency. Traditionally, valve timing was set at some balancing point and spark timing was advanced at higher engine speeds to achieve greater high speed efficiency. However, as greater engine efficiency was pursued, variable valve timing was developed to maximise combustion efficiency at all engine speeds. This was accomplished by varying the camshaft rotational timing to adjust the lobe phasing to operate the valves accordingly. Commonly, such variation has been achieved by attachment of phase control devices to an exterior end of the camshaft.
However, such units are intricate and bulky in design, and they significantly impact the overall product cost and space requirements. Moreover, since these phase bulky and heavy control units are cantilevered on the end of the c amshaft, they are susceptible to rotational run out. Such run out detracts from the precision of the cam timing control and degrades the efficiency of the combustion in the engine.
According to one aspect of the present invention, there is provided a composite camshaft having variable cam timing, comprising a sprocket and shaft assembly, a tube and cam element assembly, means, axially movable relative to said tube and said shaft, for causing said tube and cam element assembly to rotate relative to said sprocket and shaft assembly to vary cam timing, and means for axially displacing said axially movable means.
For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example to the accompanying drawings, in which:- Fig. 1 is a schematic longitudinal cross-sectional view illustrating an embodiment of a camshaft; is Fig. 2 is a schematic perspective view of a portion of the shaft which engages with a drive collar/piston assembly; Fig. 3 is a perspective view of the drive collar/piston assembly; and Fig. 4 is a cut-away perspective view of a tube and cam element assembly.
A camshaft 100 is formed by a hollow tube and cam element assembly, which has cam lobes,25 disposed along a tube 20; a sprocket and shaft assembly, comprising a sprocket 5 mounted on a shaft 10; and a drive collar/piston assembly 40, comprising a drive collar 48 and a piston 49.
The shaft 10 has two bushings 17, which support it in the tube 20, two thrust washers 18, which axially restrain the bushings 17, and a bolt 7 or other appropriate fastener which is fixed to the end of the shaft 10 to hold the assembly together. An axial shaft keyway holds a key 13 which slidably engages another keyway 43 on the inner surface of the drive collar/piston assembly 40 to prevent relative rotation between the drive collar 48 and the shaf t 10 while permitting axial motion of the drive collar/piston assembly 40 on the shaft 10. A slide stop ring 21 limits the axial travel of the drive collar/piston assembly 40 in one direction, while a compression spring 30, or some other 1 is mechanical or f luid powered device limits travel in the opposite direction and provides force to return the drive collar/piston assembly 40 to its non-displaced position. The drive collar/piston assembly 40 is axially displaced by admission of pressurised fluid to the interior cylindrical bore of the tube 20 through a fluid feed port 22. The fluid acts against the end of the piston 49 to drive the drive collar/piston assembly 40 axially leftwards as viewed in Fig. 1. Seal rings 45 and 15 are provided between the piston 49 and the tube 20 and the shaft 10, respectively, to contain the pressurised fluid within the cylindrical bore of the tube 20 against the end of the piston. A shaft seal 11 is. also provided at the other end of the tube 20 within the bushing 17.
The tube 20 has helical grooves 27 on the inner surface portion surrounding the drive collar/piston assembly 40. Helical splines on the outer surface of the drive collar 48 engage with the helical grooves 27 of the tube 20 to cause rotation of the tube 20 relative to the drive collar 48 during axial displacement of the drive collar/piston assembly 40. This is the means by which cam timing is varied. At any engine speed, the axial position of the drive collar/piston assembly is adjusted to achieve optimum cam/valve timing, usually by a computer controlled combustion regulation valve which adjusts the fluid pressure to the port 22 to adjust the axial position of the drive collar/piston assembly. This can also be accomplished directly by the engine oil pressure which responds to engine speed or by any of the several other mechanisms.
4 - The displacement of the drive collar/piston assembly 40 in either direction can be accomplished by fluid power or by mechanical or electromechanical means to control cam/valve timing continuously during operation of the engine. The present camshaft significantly decreases the intricacy of variable cam timing in camshafts while providing a compact assembly.
1

Claims (12)

1. A composite camshaft having variable cam timing, comprising a sprocket and shaft assembly, a tube and cam element assembly, means, axially movable relative to said tube and said shaft, for causing said tube and cam element assembly to rotate relative to said sprocket and shaft assembly to vary cam timing, and means for axially displacing said axially movable means.
2. A camshaft according to claim 1, wherein the means f or causing said tube and cam element assembly to rotate relative to said sprocket and shaft assembly comprises an axially slidable drive collar/piston assembly radially interposed between said shaft and said tube, said drive collar/piston assembly and said tube having interengaging means for causing relative rotation between said drive collar/piston and said tube in response to axial displacement of said drive collar/piston, and said drive collar/piston assembly and said shaft having means for preventing relative rotation between said drive collar/piston assembly and said shaft during axial movement of said drive collar/piston assembly, and there being means for axially displacing said drive collar/piston assembly to vary cam timing.
3. A camshaft according to claim 2, wherein the means for axially displacing said drive collar/piston assembly to vary cam timing comprises a port for admitting pressurised fluid to pressurise an inner portion of said tube to axially displace said drive collar/piston assembly.
A camshaft according to claim 3, further comprising means for returning said drive collar/piston assembly to a non-displaced position when said inner portion of said tube is de-pressurised.
5. A camshaft according to claim 4, wherein the means for returning said drive collar/piston assembly to a non-displaced position comprises a compression spring mounted within said tube against said drive collar/piston axially opposite to said port for admitting pressurised fluid.
6. A camshaft according to claim 2, 3, 4 or 5, wherein the inter-engaging means for causingrelative rotation between said drive collar/piston and said tube in response to axial displacement of said drive collar/piston comprises helical grooves on one of said drive collar/pist on and said tube and at least one follower projection on the other of said drive collar/piston and said tube.
7. A camshaft according to claim 2, 3, 4, 5, or 6, wherein the means for preventing relative rotation between said drive collar/piston assembly and said shaf t during axial movement of said drive collar/piston assembly comprises an axial key/keyway mechanism between said drive collar/piston assembly and said shaft.
8. A composite camshaft having variable cam timing, comprising a sprocket and shaf t assembly, including an axial key member on said shaft, a tube and cam element assembly, including helical splines disposed on an inner wall surface of said tube, an axially slidable drive collar/piston assembly radially interposed between said shaft and said tube, said drive collar having means on an outer surface for engaging said helical splines on said inner wall surface of said tube, to cause relative rotation between said drive collar/piston and said tube in response to axial displacement of said drive collar/piston, and inside means for engaging said axial key member, to prevent relative rotation between said drive collar and sa.id shaft, during 1 axial movement of said drive collar/piston assembly, and there being means for axially displacing said drive collar/piston assembly to vary cam timing.
9. A camshaft according to claim 8, wherein the means for axially displacing said drive collar/piston assembly to vary can timing comprises a port for admitting pressurised fluid to pressurise an inner portion of said tube adjacent one axial face of said drive collar/piston assembly.
10. A camshaft according to claim 8 or 9, further comprising means for returning said drive collar/piston to a non-displaced position.
11. A camshaft according to claim 10, wherein the means for returning said drive collar/piston to a nondisplaced position comprises a compression spring mounted within said tube against said drive collar/piston axially opposite to said port for admitting pressurised fluid.
12. A composite camshaft, substantially as hereinbefore described with reference to the accompanying drawings.
GB9811986A 1997-06-09 1998-06-05 Composite camshaft with internal variable cam timing mechanism Withdrawn GB2327482A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US87138697A 1997-06-09 1997-06-09

Publications (2)

Publication Number Publication Date
GB9811986D0 GB9811986D0 (en) 1998-07-29
GB2327482A true GB2327482A (en) 1999-01-27

Family

ID=25357333

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9811986A Withdrawn GB2327482A (en) 1997-06-09 1998-06-05 Composite camshaft with internal variable cam timing mechanism

Country Status (3)

Country Link
JP (1) JPH1163166A (en)
DE (1) DE19825814A1 (en)
GB (1) GB2327482A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2424256A (en) * 2005-03-16 2006-09-20 Mechadyne Ltd SCP assembly with spring mounted on camshaft rather than within phaser housing
US8146551B2 (en) 2007-06-19 2012-04-03 Borgwarner Inc. Concentric cam with phaser
US8186319B2 (en) 2007-07-02 2012-05-29 Borgwarner Inc. Concentric cam with check valves in the spool for a phaser
US8584634B2 (en) 2008-09-19 2013-11-19 Borgwarner Inc. Phaser built into a camshaft or concentric camshafts
CN108167042A (en) * 2018-01-31 2018-06-15 东风商用车有限公司 Variable timing system of engine

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7140335B2 (en) * 2004-09-17 2006-11-28 Kaymor, Llc Dynamic valve timing adjustment mechanism for internal combustion engines
DE102009039733A1 (en) * 2009-09-02 2011-03-10 Thyssenkrupp Presta Teccenter Ag Valve drive for gas exchange valves of an internal combustion engine with axially displaceable cam units
DE102009054054A1 (en) * 2009-11-20 2011-05-26 Schaeffler Technologies Gmbh & Co. Kg Mounting arrangement and method for mounting a pressure accumulator for internal combustion engines
DE102015221868A1 (en) 2015-11-06 2017-05-11 Mahle International Gmbh camshaft

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4787345A (en) * 1986-05-14 1988-11-29 Bayerische Motoren Werke A.G. Arrangement for the relative angular position change of two shafts drivingly connected with each other, especially between a crankshaft supported in an engine housing of an internal combustion engine and a cam shaft
WO1991007574A1 (en) * 1989-11-11 1991-05-30 Audi Ag Drive arrangement for a camshaft fitted in the cylinder head of an internal combustion engine
EP0582846A1 (en) * 1992-08-13 1994-02-16 Bayerische Motoren Werke Aktiengesellschaft Internal combustion piston engine with gas exchange valves per cylinder

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4787345A (en) * 1986-05-14 1988-11-29 Bayerische Motoren Werke A.G. Arrangement for the relative angular position change of two shafts drivingly connected with each other, especially between a crankshaft supported in an engine housing of an internal combustion engine and a cam shaft
WO1991007574A1 (en) * 1989-11-11 1991-05-30 Audi Ag Drive arrangement for a camshaft fitted in the cylinder head of an internal combustion engine
EP0582846A1 (en) * 1992-08-13 1994-02-16 Bayerische Motoren Werke Aktiengesellschaft Internal combustion piston engine with gas exchange valves per cylinder

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2424256A (en) * 2005-03-16 2006-09-20 Mechadyne Ltd SCP assembly with spring mounted on camshaft rather than within phaser housing
US8146551B2 (en) 2007-06-19 2012-04-03 Borgwarner Inc. Concentric cam with phaser
US8186319B2 (en) 2007-07-02 2012-05-29 Borgwarner Inc. Concentric cam with check valves in the spool for a phaser
US8584634B2 (en) 2008-09-19 2013-11-19 Borgwarner Inc. Phaser built into a camshaft or concentric camshafts
CN108167042A (en) * 2018-01-31 2018-06-15 东风商用车有限公司 Variable timing system of engine

Also Published As

Publication number Publication date
JPH1163166A (en) 1999-03-05
GB9811986D0 (en) 1998-07-29
DE19825814A1 (en) 1998-12-10

Similar Documents

Publication Publication Date Title
KR100280649B1 (en) Devices for continuously and automatically adjusting the angle between two shafts in driving relationship
US5247914A (en) Intake- and/or exhaust-valve timing control system for internal combustion engines
EP1403488B1 (en) Compression ratio variable device of internal combustion engine
US4895113A (en) Device for relative angular adjustment between two drivingly connected shafts
US5566651A (en) Device for continuous angular adjustment between two shafts in driving relationship
US7182053B2 (en) Camshaft adjuster for an internal combustion engine
US4862843A (en) Valve timing control device for use in internal combustion engine
JP3933129B2 (en) Flywheel equipment
US5542383A (en) Dual output camshaft phase controller
US6481401B1 (en) Device for independent hydraulic actuation of the phase and axial position of a camshaft
JP3325567B2 (en) Adjustment device for adjusting the angular position of rotation between camshaft and drive member
WO2006034176A2 (en) Dynamic valve timing adjustment mechanism for internal combustion engines
EP0818609B1 (en) Valve timing control devices
JP2005002992A (en) Phase shifter
KR0152373B1 (en) Camshaft phase changing device
US5117785A (en) Valve timing control device for internal combustion engine
US5355849A (en) Automatic variator valve overlap or timing and valve section
GB2327482A (en) Composite camshaft with internal variable cam timing mechanism
CA2025059C (en) Camshaft phasing drive with wedge actuators
US5893345A (en) Valve control apparatus for an internal combustion engine
US5150671A (en) Intake- and/or exhaust-valve timing control system for internal combustion engines
JP2760637B2 (en) Valve timing control device for internal combustion engine
US20210172346A1 (en) Valve opening and closing timing control device
JPH0726921A (en) Valve timing control device for engine
JPH07139318A (en) Valve-timing adjusting device

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)