Information
-
Patent Grant
-
6591802
-
Patent Number
6,591,802
-
Date Filed
Wednesday, April 10, 200222 years ago
-
Date Issued
Tuesday, July 15, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Denion; Thomas
- Chang; Ching
Agents
-
CPC
-
US Classifications
Field of Search
US
- 123 9015
- 123 9016
- 123 9017
- 123 9027
- 123 9031
- 123 9039
- 123 9043
- 123 9044
- 123 9045
- 074 559
- 074 567
- 074 569
-
International Classifications
-
-
Disclaimer
Terminal disclaimer
Abstract
A variable valve actuating mechanism includes an output cam configured for being pivotally disposed upon an input shaft. A first link arm is pivotally coupled at a first end thereof to the output cam. A rocker arm is pivotally coupled at a first end thereof to a second end of the link arm. A first frame member is configured for being pivotally disposed upon the input shaft. Lash adjusting means pivotally couple together a first end of the first frame member and a second end of the rocker arm. The lash adjusting means adjusts the position of the rocker arm relative to the input shaft.
Description
TECHNICAL FIELD
The present invention relates to a variable valve actuating mechanism. More particularly, the present invention relates to a variable valve actuating mechanism having a rotary hydraulic lash adjuster.
BACKGROUND OF THE INVENTION
Modern internal combustion engines may incorporate advanced throttle control systems, such as, for example, intake valve throttle control systems, to improve fuel economy and performance. Generally, intake valve throttle control systems control the flow of gas and air into and out of the engine cylinders by varying the timing, duration and/or lift (i.e., the valve lift profile) of the cylinder valves in response to engine operating parameters, such as engine load, speed, and driver input. Intake valve throttle control systems vary the valve lift profile through the use of variously-configured mechanical and/or electromechanical devices, collectively referred to herein as variable valve actuation (VVA) mechanisms. Several examples of particular embodiments of VVA mechanisms are detailed in commonly assigned U.S. Pat. Nos. 5,937,809 and 6,019,076, the disclosures of which are incorporated herein by reference.
Generally, a conventional VVA mechanism includes a rocker arm that carries an input cam follower, such as a roller. The input cam follower engages an opening or input cam lobe of a rotating input shaft, such as the engine camshaft, and transfers rotation of the input cam lobe to oscillation of the rocker arm toward and away from the input shaft in a generally radial direction. The oscillation of the rocker arm is transferred via a link arm to pivotal oscillation of an output cam relative to the input shaft. The pivotal oscillation of the output cam is transferred to actuation of an associated valve by an output cam follower, such as, for example, a roller finger follower. The rocker arm also carries a closing cam follower, such as, for example, a slider pad, that engages a closing cam lobe of the rotary input shaft. The closing cam follower transfers rotation of the closing cam lobe to the rocker arm, thereby ensuring that the output cam is pivoted back or returned to its starting or base angular orientation.
A desired valve lift profile is obtained by pivoting a control shaft into a predetermined angular orientation relative to a centerline thereof. A frame member is pivotally coupled at one end thereof to the control shaft and at the other end thereof to the rocker arm. The pivotal movement of the control shaft is transferred, via the frame, rocker arm and link arm, to pivotal movement of the output cam relative to a central axis of the input shaft. Thus, pivoting the control shaft places the output cam into the base or starting angular orientation. The base or starting angular orientation of the output cam, in turn, determines the portion of the lift profile thereof that will engage the output cam follower during pivotal oscillation of the output cam. The lift profile of the output cam that engages the cam follower determines the valve lift profile.
Conventional VVA mechanisms may also include a lash adjustment means. The lash adjustment means is adjusted during assembly of the VVA mechanism and/or engine to compensate for manufacturing tolerances and/or component dimensional variation, thereby removing lash from the mechanism. This adjustment step or process in the assembly of the mechanism or engine is time consuming and labor intensive. Further adjustment of the lash adjustment means is typically required periodically thereafter, such as, for example, to compensate for wear and tear of mechanism components. Such further adjustment requires a vehicle owner to return the vehicle to a service provider for periodic maintenance.
Therefore, what is needed in the art is a VVA mechanism having a lash adjustment means that reduces and/or eliminates the need for manual adjustment of lash during assembly and/or installation of the VVA mechanism.
Furthermore, what is needed in the art is a VVA mechanism having a lash adjustment means that substantially reduces the need for periodic adjustment/maintenance to reduce/remove the lash from the VVA mechanism.
Still further, what is needed in the art is VVA mechanism having a lash adjustment means that automatically reduces/removes lash from the VVA mechanism.
Moreover, what is needed in the art is a VVA mechanism having an automatic lash adjustment means that substantially reduces and/or eliminates the need for periodic maintenance and/or manual adjustment in order to reduce/remove lash.
SUMMARY OF THE INVENTION
The present invention provides a variable valve actuating mechanism having automatic lash adjustment.
The present invention comprises, in one form thereof, an output cam configured for being pivotally disposed upon an input shaft. A first link arm is pivotally coupled at a first end thereof to the output cam. A rocker arm is pivotally coupled at a first end thereof to a second end of the link arm. A first frame member is configured for being pivotally disposed upon the input shaft. Lash adjusting means pivotally couple together the first end of the first frame member and the second end of the rocker arm. The lash adjusting means adjusts the position of the rocker arm relative to the input shaft.
An advantage of the present invention is that the need for manual adjustment of lash during assembly of a VVA mechanism is substantially reduced.
Another advantage of the present invention is that the need for periodic adjustment/maintenance to reduce/remove lash in the VVA mechanism is substantially reduced.
A further advantage of the present invention is that lash is automatically reduced/removed from the VVA mechanism.
A still further advantage of the present invention is that the need for periodic maintenance and/or manual adjustment of the VVA mechanism in order to reduce/remove lash therefrom is substantially reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become apparent and be more completely understood by reference to the following description of one embodiment of the invention when read in conjunction with the accompanying drawings, wherein:
FIG. 1
is a perspective, front view of one embodiment of a variable valve actuating (VVA) mechanism having a rotary hydraulic lash adjuster of the present invention;
FIG. 2
is a perspective, rear view of the VVA of
FIG. 1
;
FIG. 3
is a front, cross-sectional view of one embodiment of the rotary hydraulic lash adjuster of
FIG. 1
;
FIG. 4
is a partial, axially-sectioned view of the VVA mechanism of
FIG. 1
; and
FIG. 5
is a partial, axially-sectioned view of the VVA mechanism of FIG.
1
.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and particularly to
FIGS. 1 and 2
, there is shown one embodiment of a variable valve actuating (VVA) mechanism having a rotary hydraulic lash adjuster (RHLA) of the present invention.
VVA mechanism
10
, as is known in the art, is operably associated with rotary input shaft or camshaft
12
(hereinafter referred to as camshaft
12
) of engine
14
. Camshaft
12
has a central axis A, and includes an input cam lobe
12
a
and a closing cam lobe
12
b
. Cam lobes
12
a
and
12
b
rotate as substantially one body with camshaft
12
. Valves
16
a
and
16
b
are associated with a cylinder (not shown) of engine
14
and with respective cam followers
18
a
and
18
b.
VVA mechanism
10
includes frame members
20
a
and
20
b
, link arms
22
a
and
22
b
, rocker arm assembly
24
, output cams
26
a
and
26
b
, and rotary hydraulic lash adjuster (RHLA)
30
. Generally, VVA mechanism
10
transfers rotation of input cam lobe
12
a
to pivotal oscillation of output cams
26
a
and
26
b
to thereby actuate valves
16
a
and
16
b
according to a desired valve lift profile.
Frame members
20
a
and
20
b
are pivotally disposed on camshaft
12
on respective sides of input and closing cam lobes
12
a
and
12
b
, respectively. Frame members
20
a
and
20
b
, as will be more particularly described hereinafter, are pivotally coupled to rocker arm assembly
24
. Frame members
20
a
and
20
b
are also pivotally coupled to control shaft
32
by respective coupling means
34
a
and
34
b
, such as, for example, shaft clamps.
Link arms
22
a
and
22
b
are elongate arm members that are pivotally coupled at a first end thereof to opposite sides of rocker arm assembly
24
and at a second end thereof to a respective output cam
26
a
and
26
b.
Rocker arm assembly
24
is pivotally coupled, as will be more particularly described hereinafter, at a first end thereof to frame members
20
a
,
20
b
. Rocker arm assembly
24
is pivotally coupled, such as, for example, by pins, at a second end thereof to link arms
22
a
and
22
b
. Rocker arm assembly
24
, as is known in the art, carries an input cam follower (not shown) and a closing cam follower (not shown), such as, for example, rollers or slider pads (not shown), that engage a corresponding one of input and closing cams
12
a
and
12
b.
Output cams
26
a
and
26
b
are pivotally disposed upon camshaft
12
. More particularly, output cam
26
a
is pivotally disposed upon camshaft
12
on a first side of input and closing cam lobes
12
a
,
12
b
and output cam
26
b
is disposed on a second side of input and closing cam lobes
12
a
,
12
b
. Output cam
26
a
is pivotally coupled to link arm
22
a
and output cam
26
b
is pivotally coupled to link arm
22
b.
In use, VVA mechanism
10
actuates and varies the valve lift of valves
16
a
,
16
b
, in a generally similar manner to that of a conventional VVA mechanism. Generally, VVA mechanism
10
converts rotation of camshaft
12
to a fixed range of pivotal oscillation of output cams
26
a
and
26
b
relative to central axis A. More particularly, as described above, input cam lobe
12
a
engages the corresponding cam follower (not shown) carried by rocker arm
24
. Rotation of input cam lobe
12
a
thus displaces rocker arm
24
in a generally radial direction away from central axis A. The displacement of rocker arm
24
is transferred via link arms
22
a
and
22
b
to pivotal movement of output cams
26
a
and
26
b
in a counterclockwise direction relative to central axis A of camshaft
12
.
Closing cam
12
b
is a predetermined amount out of phase relative to input cam lobe
12
a
. Closing cam
12
b
engages the corresponding cam follower carried by rocker arm
24
to return output cams
26
a
and
26
b
to a base or starting angular orientation relative to central axis A of camshaft
12
. More particularly, as input cam lobe
12
a
rotates from the lift or nose portion of its profile toward a lower lift or base circle portion, the lift portion of closing cam lobe
12
b
engages the corresponding cam follower carried by rocker arm
24
. Closing cam lobe
12
b
displaces, or pulls, rocker arm
24
in a generally radial direction toward central axis A of camshaft
12
, thereby pivoting (via link arms
22
a
and
22
b
) output cams
26
a
and
26
b
back to their base or starting angular orientation.
A desired valve lift profile for associated valves
16
a
,
16
b
is obtained by placing control shaft
32
in a predetermined angular orientation relative to central axis S (
FIGS. 1 and 2
) thereof. The pivoting of control shaft
32
is transferred via frame members
20
a
,
20
b
, rocker arm
24
, and link arms
22
a
and
22
b
to pivoting of output cams
26
a
and
26
b
relative to central axis A of camshaft
12
. Thus, the desired portion of the lift profiles of output cams
26
a
and
26
b
are disposed within the pivotal oscillatory range thereof relative to cam followers
18
a
,
18
b
. As output cams
26
a
,
26
b
are pivotally oscillated, the desired portions of the lift profiles thereof engage cam followers
18
a
,
18
b
to thereby actuate valves
16
a
and
16
b
according to the desired lift profile.
Although VVA
10
mechanism actuates and varies the lift profile of valves
16
a
and
16
b
in a manner generally similar to a conventional VVA mechanism, the automatic reduction and/or removal of lash distinguishes VVA mechanism
10
relative to a conventional VVA mechanism. As will be described more particularly hereinafter, RHLA
30
automatically reduces and/or removes the lash within VVA mechanism
10
.
RHLA
30
, as best shown in
FIGS. 3-5
, includes cylinder
42
, fixed vane
44
, movable vane
46
, biasing means
48
, valve assembly
50
and eccentric shaft or pin
52
. Generally, eccentric pin
52
pivotally couples frame members
20
a
and
20
b
to rocker arm
24
, and enables the position of rocker arm
24
to be adjusted in a generally radial direction toward and away from camshaft
12
to thereby adjust and/or reduce lash in VVA mechanism
10
.
Cylinder
42
is a cylindrical body having central axis C, and contains a hydraulic fluid (not shown) such as, for example, oil. Cylinder
42
includes sidewall
62
, fluid port
64
, top
66
(
FIG. 4
) and bottom
68
(FIG.
4
). Each of top
66
and bottom
68
are attached in a fluid and fluid tight manner to sidewall
62
at respective and opposite ends (not referenced) thereof. Fluid port
64
is defined by bottom
68
. Cylinder
42
further includes high-pressure chamber
70
and low-pressure chamber
72
. High-pressure chamber
70
is defined by a corresponding portion of sidewall
62
, fixed vane
44
and movable vane
46
. Low-pressure chamber
72
is defined by a corresponding portion of sidewall
62
, fixed vane
44
and movable vane
46
. Cylinder
42
is affixed, such as, for example, by bolts or other fasteners, to frame member
20
b.
Fixed vane
44
is disposed within cylinder
42
, and includes outer and inner ends (not referenced). The outer end is fixed to and/or integral with sidewall
62
of cylinder
42
. Inner seal
76
is disposed on the inner end of fixed vane
44
and engages eccentric pin
52
in a fluid tight manner. Fixed vane
44
extends axially through cylinder
42
and is in sealing engagement with each of top
66
and bottom
68
of cylinder
42
.
Movable vane
46
includes an inner end and an outer end (neither of which is referenced). The inner end of movable vane
46
is in sealing engagement and/or integral with eccentric pin
52
. Thus, eccentric pin
52
and movable vane
46
pivot or rotate as substantially one body. Outer seal
78
is disposed on the outer end of movable vane
46
and engages the inner surface (not referenced) of sidewall
62
in a fluid tight manner. Movable vane
46
extends axially through cylinder
42
and is in sealing engagement with each of the top
66
and bottom
68
of cylinder
42
. Movable vane
46
defines fluid passageway
80
therethrough, which fluidly connects high and low pressure chambers
70
and
72
, respectively.
Biasing means
48
, such as, for example, a torsion and/or coil spring, engages or is affixed at one end (not referenced) thereof to movable vane
46
and at the other end (not referenced) thereof to fixed vane
44
or to eccentric pin
52
. Biasing means
48
applies a clockwise-directed torque upon movable vane
46
to thereby rotate eccentric pin
52
in a clockwise direction and remove lash from VVA mechanism
10
, as will be more particularly described hereinafter.
Valve assembly
50
is a conventional check ball type valve that controls the flow of working fluid within cylinder
42
between high and low pressure chambers
70
and
72
, respectively. Valve assembly
50
is disposed on movable vane
46
and in association with fluid passageway
80
defined thereby.such that valve assembly
50
controls the flow of fluid through passageway
80
between high and low pressure chambers
70
and
72
, respectively.
Eccentric pin
52
, as best shown in
FIGS. 4 and 5
, is an elongate pin member having first and second portions
52
a
(
FIG. 4
) and
52
b
(FIG.
5
), respectively, having a common centerline P
1
, and an eccentric portion
52
c
having a centerline P
2
. Centerline P
1
and P
2
are substantially parallel relative to and spaced apart from each other. Centerlines P
1
and P
2
are spaced apart from each other from approximately 0.025 millimeters (mm) to approximately 5.00 mm.
A first segment (not referenced) of first portion
52
a
of eccentric pin
52
disposed within cylinder
42
such that centerline P
1
thereof is substantially coaxial with central axis C of cylinder
42
. First portion
52
a
extends axially through bottom
68
of cylinder
42
such that a second segment (not referenced) of first portion
52
a
is pivotally disposed within frame-to-rocker pin bore
82
formed in frame member
20
b
. The interface of bottom
68
and first portion
52
a
of eccentric pin
52
is sealed by seal
84
in a fluid tight manner to prevent fluid from escaping from within cylinder
42
.
Second portion
52
b
of eccentric pin
52
extends axially from eccentric portion
52
c
at an end thereof that is opposite to first portion
52
a
. Second portion
52
b
is disposed at least partially within frame-to-rocker pin bore
86
formed in frame member
20
a.
Eccentric portion
52
c
(not referenced) of eccentric pin
52
extends axially from first portion
52
a
to second portion
52
b
. Eccentric portion
52
c
is disposed at least partially within and extends through rocker-to-frame pin bore
88
formed in rocker arm
24
.
In use, VVA
10
mechanism actuates and varies the lift profile of valves
16
a
and
16
b
in a generally similar manner to a conventional VVA mechanism. However, VVA mechanism
10
includes RHLA
30
, which automatically reduces and/or removes lash from. VVA mechanism
10
and which distinguishes VVA mechanism
10
from a conventional VVA mechanism. Generally, RHLA
30
removes lash from VVA mechanism
10
by rotating eccentric pin
52
which, in turn, adjusts the radial position of rocker arm
24
relative to central axis A of camshaft
12
.
More particularly, and as stated above, biasing means
48
applies a force in the clockwise direction directly upon eccentric pin
52
or indirectly upon eccentric pin
52
via movable vane
46
. With the input and closing cam followers (not referenced) carried by rocker arm
24
in engagement with the base circle portions of input cam
12
a
and closing cam
12
b
, respectively, VVA mechanism
10
is in a condition of low applied force or torque. Under this condition of low applied force, the predetermined force applied directly or indirectly to eccentric pin
52
by biasing means
48
is greater than the fluid pressure within low-pressure chamber
72
. Thus, movable vane
46
is caused to pivot in the clockwise direction, thereby unseating the ball of valve assembly
50
and enabling oil to flow from low-pressure chamber
72
into high-pressure chamber
70
.
The clockwise pivoting of moving vane
46
is transferred to clockwise pivoting of eccentric pin
52
, which is affixed to and/or integral with moving vane
46
. Thus, as eccentric pin
52
pivots in a clockwise direction, centerline P
2
of eccentric section
52
c
pivots relative to centerline P
1
of first and second sections
52
a
,
52
b
. The clockwise pivoting of eccentric pin
52
adjusts the position of rocker arm
24
in a generally radial direction toward camshaft
12
until the input and closing cam followers carried by rocker arm
24
engage input cam
12
a
and closing cam
12
b
, respectively, thereby removing lash from VVA mechanism
10
. Eccentric pin
52
pivots until the cam followers engage their corresponding cams, at which point further clockwise pivoting thereof is precluded by the engagement of the followers with the respective cams.
As the input cam
12
a
and closing cam
12
b
rotate out of an orientation wherein the base circle portions thereof are in engagement with a corresponding cam follower, and into an orientation wherein a lift portion of the profiles thereof engage a corresponding cam, force levels within VVA mechanism
10
increase relative to the force levels present in the base circle situation described above. The increased force levels within VVA mechanism
10
tends to pivot eccentric pin
52
in a counterclockwise direction, which would require that fluid flow from high-pressure chamber
70
into low-pressure chamber
72
. However, valve assembly
50
substantially precludes fluid from flowing through passageway
80
and into low-pressure chamber
72
. Thus, movable vane
46
and eccentric pin
52
are substantially precluded from pivotal movement, and the lash within VVA mechanism
10
remains substantially unchanged.
It should be particularly noted when the force levels within VVA mechanism
10
increase relative to the force levels present in the base circle situation, RHLA
30
is designed to permit a certain amount of fluid to gradually escape from high-pressure chamber
70
and into low-pressure chamber
72
. That is, RHLA
30
is designed with a controlled leakage, provided by, for example, an orifice or dimensional clearances, between high-pressure chamber
70
and low-pressure chamber
72
. Accordingly, under such an increased or high-force condition, movable vane
46
and eccentric pin
52
are pivoted slightly in a counterclockwise direction thereby slightly increasing the amount of lash within VVA mechanism
10
. This slight increase in the lash is necessary to compensate for thermal expansion and/or growth of components within VVA mechanism
10
.
It should further be particularly noted that, as shown in
FIG. 4
, RHLA
30
is fluidly coupled to a source of hydraulic fluid, such as, for example, oil. More particularly, fluid port or inlet
64
of cylinder
42
is, when in use, in fluid communication with a source of pressurized hydraulic fluid, such as, for example, oil supply
94
.
Moreover, it should be particularly noted that, as shown in the drawings, optional bearings (not referenced) are disposed between eccentric pin
52
and each of frame member
20
b
(i.e., in frame-to-rocker pin bore
82
formed in frame member
20
b
) and frame member
20
a
(i.e., within frame-to-rocker pin bore
86
formed in frame member
20
a
).
In the embodiment shown, biasing means
48
is disposed within cylinder
42
. However, as shown in
FIG. 5
, the present invention can be alternately configured with biasing means
48
′ affixed to frame member
20
a
and to second portion
52
b
of eccentric pin
52
to thereby bias movable vane
46
in a clockwise direction. Furthermore, the present invention can be alternately configured with the biasing means placed virtually any place that is convenient for a particular application.
In the embodiment shown, VVA mechanism
10
is configured with RHLA
30
having one movable vane and one fixed vane. However, it is to be understood that the present invention can be alternately configured with a RHLA having multiple vanes to increase stiffness and/or reduce the size of the RHLA.
In the embodiment shown, RHLA
30
is configured with a separate cylinder
42
that is affixed to frame member
20
b
of VVA mechanism
10
. However, it is to be understood that the present invention can be alternately configured, such as, for example, with a cylinder that is integral with and/or defined within one of the frame members of the VVA mechanism.
In the embodiment shown, RHLA
30
includes a conventional check ball type valve to control the flow of fluid between the two chambers. However, it is to be understood that the present invention can be alternately configured with other types of valves, such as, for example, a flapper valve or other suitable type of fluid control valve.
In the embodiment shown, VVA mechanism
10
is shown as having a particular and specific desmodronic configuration. However, it is to be understood that the present invention can be alternately configured, such as, for example, with variously configured desmodronic variable valve actuation mechanisms.
While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the present invention using the general principles disclosed herein. Further, this application is intended to cover such departures from the present disclosure as come within the known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
Claims
- 1. A variable valve actuating mechanism, comprising:an output cam configured for being pivotally disposed upon an input shaft; a first link arm pivotally coupled at a first end thereof to said output cam; a rocker arm pivotally coupled at a first end thereof to a second end of said link arm; a first frame member configured for being pivotally disposed upon the input shaft; and lash adjusting means pivotally coupling together a first end of said first frame member and a second end of said rocker arm, said lash adjusting means configured for adjusting a position of said rocker arm relative to the input shaft.
- 2. A variable valve actuating mechanism, comprising:an output cam configured for being pivotally disposed upon an input shaft; a first link arm pivotally coupled at a first end thereof to said output cam; a rocker arm pivotally coupled at a first end thereof to a second end of said link arm; a first frame member configured for being pivotally disposed upon the input shaft; and lash adjusting means configured for adjusting a position of said rocker arm relative to the input shaft, said lash adjusting means including: a cylinder having a cylinder central axis, a sidewall, a top and a bottom, said sidewall interconnected with said top and bottom in a fluid tight manner, said cylinder configured for containing a fluid; and an elongate eccentric pin pivotally coupling together said first frame member and said rocker arm, said eccentric pin pivoted relative to said cylinder central axis by fluid pressure within said cylinder to thereby adjust the position of said rocker arm relative to said input shaft.
- 3. The variable valve actuating mechanism of claim 2, wherein:said eccentric pin further comprises: a first portion having a first centerline, said first centerline being substantially coaxial with said central axis of said cylinder, said first portion having an internal and external segment, said internal segment being disposed within said cylinder, said external segment being disposed external to said cylinder, said first end of said first frame member being pivotally associated with said external segment; a second portion adjoining said external segment of said first portion, said second portion disposed external to said cylinder and having a second centerline, said second centerline being spaced apart from and substantially parallel relative to said first centerline, said rocker arm being pivotally associated with said second portion; and said cylinder further comprises: a movable vane in sealing engagement with said top and said bottom of said cylinder, said movable vane having an inner end and an outer end, said inner end being one of affixed to and integral with said internal segment of said first portion of said eccentric pin, said outer end sealingly engaging said sidewall; and a fixed vane disposed in sealing engagement with each of said sidewall, said top, said bottom and said internal segment of said eccentric pin.
- 4. The variable valve actuating mechanism of claim 3, wherein said first and said second centerlines are separated by from approximately 0.025 millimeters (mm) to approximately 5.0 mm.
- 5. The variable valve actuating mechanism of claim 3, wherein said second end of said rocker arm defines a rocker arm bore therethrough, said first end of said first frame member defines a first frame bore therethrough, said external segment of said first portion of said eccentric pin being pivotally disposed at least partially within said first frame bore, said second portion of said eccentric pin being pivotally disposed at least partially within said rocker arm bore.
- 6. The variable valve actuating mechanism of claim 5, further comprising:a second frame member having a first end, said first end defining a second frame bore therethrough, said second frame member being pivotally disposed upon the input shaft; and wherein said eccentric pin includes a third portion substantially concentric relative to said first centerline, said third portion adjoining said second portion at an end thereof opposite said first portion, said third portion being pivotally disposed at least partially within said second frame bore.
- 7. The variable valve actuating mechanism of claim 3, wherein said lash adjusting means further comprises:a first chamber conjunctively defined by said fixed vane, said movable vane and said sidewall, said first chamber configured for containing a fluid; and a second chamber conjunctively defined by said fixed vane, said movable vane and said sidewall, said second chamber configured for containing a fluid; a fluid port in fluid communication with said first chamber; a fluid passageway fluidly connecting said first and second chambers; and valve means disposed in said second chamber and controlling the flow of fluid through said fluid passageway.
- 8. The variable valve actuating mechanism of claim 3, further comprising a biasing means rotationally biasing in one of a direct or indirect manner said eccentric pin and said movable vane in a direction such that said first chamber increases in volume.
- 9. The variable valve actuating mechanism of claim 8, wherein said biasing means comprises a torsion spring disposed within said cylinder, said torsion spring engaging each of said fixed vane and one of said movable vane and said eccentric pin.
- 10. The variable valve actuating mechanism of claim 8, wherein said biasing means comprises a torsion spring disposed external to said cylinder and engaging said eccentric pin.
- 11. The variable valve actuating mechanism of claim 2, wherein said cylinder is one of affixed to and connected to said first frame member.
- 12. The variable valve actuating mechanism of claim 2, wherein said cylinder is integral and monolithic with said first frame member.
- 13. An internal combustion engine, comprising:an input shaft; and a variable valve actuating mechanism, including: an output cam pivotally disposed upon said input shaft; a first link arm pivotally coupled at a first end thereof to said output cam; a rocker arm pivotally coupled at a first end thereof to a second end of said link arm; a first frame member pivotally disposed upon said input shaft; and lash adjusting means pivotally coupling together a first end of said first frame member and a second end of said rocker arm, said lash adjusting means adjusting a position of said rocker arm relative to said input shaft.
- 14. An internal combustion engine, comprising:an input shaft; and a variable valve actuating mechanism, including: an output cam pivotally disposed upon said input shaft; a first link arm pivotally coupled at a first end thereof to said output cam; a rocker arm pivotally coupled at a first end thereof to a second end of said link arm; a first frame member pivotally disposed upon said input shaft; and lash adjusting means for adjusting a position of said rocker arm relative to said input shaft, said lash adjusting means including a cylinder and an elongate eccentric pin, said cylinder having a cylinder central axis, a sidewall, a top and a bottom, said sidewall interconnected with said top and bottom in a fluid tight manner, said cylinder configured for containing a fluid, said elongate eccentric pin pivotally coupling together said first frame member and said rocker arm, said eccentric pin pivoted relative to said cylinder central axis by fluid pressure within said cylinder to thereby adjust the position of said rocker arm relative to said input shaft.
- 15. The internal combustion engine of claim 14, wherein:said eccentric pin further comprises: a first portion having a first centerline, said first centerline being substantially coaxial with said central axis of said cylinder, said first portion having an internal and external segment, said internal segment being disposed within said cylinder, said external segment being disposed external to said cylinder, said first end of said first frame member being pivotally associated with said external segment; a second portion adjoining said external segment of said first portion, said second portion disposed external to said cylinder and having a second centerline, said second centerline being spaced apart from and substantially parallel relative to said first centerline; and said cylinder further comprises: a movable vane in sealing engagement with said top and said bottom of said cylinder, said movable vane having an inner end and an outer end, said inner end being one of affixed to and integral with said internal segment of said first portion of said eccentric pin, said outer end sealingly engaging said sidewall; and a fixed vane disposed in sealing engagement with each of said sidewall, said top, said bottom and said internal segment of eccentric pin.
- 16. The internal combustion engine of claim 15, wherein said first and said second centerlines are separated by from approximately 0.025 millimeters (mm) to approximately 5.0 mm.
- 17. The internal combustion engine of claim 15, wherein said second end of said rocker arm defines a rocker arm bore therethrough, said first end of said first frame member defines a first frame bore therethrough, said external segment of said first portion of said eccentric pin being pivotally disposed at least partially within said first frame bore, said second portion of said eccentric pin being pivotally disposed at least partially within said rocker arm bore.
- 18. The internal combustion engine of claim 17, further comprising:a second frame member having a first end, said first end defining a second frame bore therethrough, said second frame member being pivotally disposed upon said input shaft; and wherein said eccentric pin includes a third portion substantially concentric relative to said first centerline, said third portion adjoining said second portion at an end thereof opposite said first portion, said third portion being pivotally disposed at least partially within said second frame bore.
US Referenced Citations (12)