EP0063038A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Internal combustion engine and cam drive mechanism therefor
Assignee: Ford-Werke GmbH
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Filing: 1982-04-08
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Granted: —
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Expires: 2002-04-08
Abstract
Abstract An internal combustion engine has n cylinders, a piston in each cylinder connected to a crankshaft each piston being in phase or out of phase with the others by A° or a multiple thereof (A = 720/n), cams for actuating inlet and exhaust valves to each cylinder and a cam drive mechanism which rotates the cams in phased relationship with the crankshaft to open the valves in sequence for a desired angle of rotation of the crankshaft. The cam drive mechanism includes means for combining the rotational movement of the cams with a phased oscillatory movement of variable amplitude about the axis of rotation at a frequency of f times the crankshaft frequency so that the period over which the valves are opened and/or their timings is variable, f having the following values:- and f = n/2 when n = 3 or more The selection of the frequency of the oscillations allows all the cams to be mounted on the same camshaft.
Inventors
- 👤 Thomas Tsoi-Hei Ma
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 10:11
CPC Classifications
F; F01; F01L; F01L1/00; F01L1/34; F01L1/344; F01L1/348; F01L1/02; F01L1/024; F01L1/352; F01L1/356; F02; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
209 words
A cam drive mechanism for driving a camshaft of a 4-stroke internal combustion engine, the engine having one or more sets of n cylinders where n is a positive integer, a piston connected to a crankshaft reciprocable in the or each cylinder and being either in phase or out of phase with any other piston in the set to which it belongs by a phase angle A°, or an integral multiple thereof, and a camshaft carrying a plurality of rotatable cams for actuating inlet and/or exhaustvalves to the or each cylinder in the set, the cam drive mechanism comprising means for rotating the camshaft with a rotational movement which is a combination of a circular motion about its axis of rotation which has a predetermined phase relationship with the circular movement of the crankshaft and an oscillatory motion about its axis of rotation which also has a predetermined phase relationship with the crankshaft, and means for varying the amplitude of the oscillatory motion whereby the timing of the valve may be varied characterised in that speed of the circular movement is half the speed of the crankshaft and in that the oscillations have a frequency of f times the frequency of rotation of the crankshaft, wherein:- r or more
Claim 2
Dependent Claim
209 words
A cam drive mechanism for driving a camshaft of a 4-stroke internal combustion engine, the engine having one or more sets of n cylinders where n is a positive integer, a piston connected to a crankshaft reciprocable in the or each cylinder and being either in phase or out of phase with any other piston in the set to which it belongs by a phase angle A°, or an integral multiple thereof, and a camshaft carrying a plurality of rotatable cams for actuating inlet and/or exhaustvalves to the or each cylinder in the set, the cam drive mechanism comprising means for rotating the camshaft with a rotational movement which is a combination of a circular motion about its axis of rotation which has a predetermined phase relationship with the circular movement of the crankshaft and an oscillatory motion about its axis of rotation which also has a predetermined phase relationship with the crankshaft, and means for varying the amplitude of the oscillatory motion whereby the timing of the valve may be varied characterised in that speed of the circular movement is half the speed of the crankshaft and in that the oscillations have a frequency of f times the frequency of rotation of the crankshaft, wherein:- r or more
Claim 3
Dependent Claim
59 words
A mechanism according to claim 1 comprising a rotatable drive member drivable by the crankshaft, and a connection for transmitting rotational movement of the drive member to the camshaft and which permits relative angular movement of the camshaft and the drive member, and means for causing oscillations in the relative angular orientation of the drive member and the camshaft.
Claim 4
Dependent Claim
59 words
A mechanism according to claim 2 including an epicyclic gear train having a sun gear, a planet gear and a ring gear, one gear being drivable by the crankshaft, another gear being adapted for connection to the camshaft and means for oscillating the third gear to vary the relative angular orientation between the sun gear and the planet gear.
Claim 5
Dependent Claim
34 words
A mechanism according to claim 3 wherein the oscillating means comprises a link connected at one end to the third gear and at the other end to a rotary member drivable by the crankshaft.
Claim 6
Dependent Claim
44 words
A mechanism according to claim 4 wherein the rotary member comprises a crank wheel and the means for controlling the amplitude of the oscillatory movement comprises a pivot slidable along the link and means for adjusting the position of the pivot along the link.
Claim 7
Dependent Claim
47 words
A mechanism according to claim 2 wherein the connection between the drive member and the camshaft comprises an axially reciprocable helically splined element and means for axially, reciprocating the said element to effect the variation in the relative angular orientation of the camshaft and the drive member.
Claim 8
Dependent Claim
19 words
A mechanism according to claim 6 wherein the means for axially reciprocating the splined element comprises a cam mechanism.
Claim 9
Dependent Claim
66 words
A mechanism according to claim 7 wherein the cam mechanism comprises a ball bearing race one track of which is formed by a radial face of the splined element, the other track of which is formed by a fixed radial face, one of the tracks comprising circumferential undualtions, ball bearings positioned between the two races, and means for biasing the splined element towards the radial face.
Claim 10
Dependent Claim
46 words
A mechanism according to claim 8 wherein the axial depth of the undulations varies in the radial direction, and the means for varying the amplitude of the oscillation comprises means for varying the radial position of the ball bearings in relation-to the said one radial face.
Claim 11
Dependent Claim
74 words
A mechanism according to claim 1 wherein the cam drive mechanism comprises a first drive wheel adapted to be driven by the crankshaft, a second drive wheel adapted to drive the camshaft, and drive belt or chain interconnecting the two drive wheels and means for cyclically varying the relative lengths of the runs of drive belt or chain between the two drive wheels to effect the combination of the rotary movement with the oscillations.
Claim 12
Dependent Claim
63 words
A mechanism according to claim 10 wherein the means for cyclically varying the relative lengths of the runs of the drive belt or chain comprising two idler wheels over each of which a respective one of the runs of the drive belt or chain passes, the idler wheels being mounted for movement in synchronism to displace the drive belt in opposite radial directions.
Claim 13
Dependent Claim
34 words
A mechanism according to claim 11 wherein the idler wheels are mounted on a linkage reciprocable by a rotatable drive member driven by the crankshaft and connected to the linkage by an eccentric drive.
Claim 14
Dependent Claim
62 words
comprises 13. A mechanism according to claim 1 wherein the drive means/ a rotatable drive member adapted to be connected between the crankshaft and the camshaft by means of an eccentric coupling which superimposes oscillations on rotational movement produced by the crankshaft, and the means for varying the amplitude of the oscillations comprises means for varying the eccentricity of the eccentric coupling.
Claim 15
Dependent Claim
87 words
A mechanism according to claim 13 wherein the rotatable member is adapted to be driven from the crankshaft at f times the speed thereof and the eccentric coupling comprises a rotatable intermediate member driven by the drive member, the intermediate member and the drive member being mounted for relative movement into a position to which the axis of rotation of the intermediate member and the drive member are eccentric to each other, and the intermediate member is drivingly connected to the camshaft, through a speed change gear.
Claim 16
Dependent Claim
19 words
A mechanism according to claim 14 wherein the intermediate member is mounted for movement relative to the drive member.
Claim 17
Dependent Claim
47 words
A mechanism according to claim 15 wherein the drive member is connected to the intermediate member by a pin which is mounted in one member eccentrically with respect to the axis of rotation of that member and which engages in a radial slot in the other member.
Claim 18
Dependent Claim
52 words
A mechanism according to claim 16 wherein the intermediate member is connected to a rotatable member of the reduction gear by a pin which is mounted in one of the members eccentrically with respect to the axis of rotation of that member, and which engages a radial slot in the other member.
Claim 19
Dependent Claim
17 words
1 8. A mechanism according to claim 16 or claim 17 wherein the intermediate member is slotted.
Claim 20
Dependent Claim
41 words
A cam drive mechanism for an internal combustion engine substantially as hereinbefore described with reference to any one of Figures 1 to 5, or Figures 6 to 10, or Figures 11 to 13 or Figure 14 or Figures 15 or 16.
Claim 21
Dependent Claim
41 words
A cam drive mechanism for an internal combustion engine substantially as hereinbefore described with reference to any one of Figures 1 to 5, or Figures 6 to 10, or Figures 11 to 13 or Figure 14 or Figures 15 or 16.
Claim 22
Dependent Claim
110 words
An internal combustion engine comprising one or more sets of n cylinders (where n is an integer); a piston connected to a crankshaft reciprocable in the or each cylinder and being either in phase or out of phase by A°, or an integral multiple thereof, with any other pistons in the set to which it belongs;rotatable cams for actuating inlet and/or exhaust valves to the or each cylinder characterised in that, for the or each set of cylinders, the cams are mounted on a respective common camshaft and in that the or each camshaft is -driven by a cam drive mechanism according to any one of claims 1 to 19.
Claim 23
Dependent Claim
13 words
An engine according to claim 20 comprising a single set of four cylinders.
References Cited (Backward Citations)
No citation records indexed.
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