U.S. patent application number 10/408918 was filed with the patent office on 2004-10-14 for dual track variable orifice mount.
This patent application is currently assigned to DELPHI TECHNOLOGIES INC.. Invention is credited to Bodie, Mark O., Long, Mark W., Tewani, Sanjiv G..
Application Number | 20040201149 10/408918 |
Document ID | / |
Family ID | 33029727 |
Filed Date | 2004-10-14 |
United States Patent
Application |
20040201149 |
Kind Code |
A1 |
Bodie, Mark O. ; et
al. |
October 14, 2004 |
DUAL TRACK VARIABLE ORIFICE MOUNT
Abstract
A powertrain mount comprises an orifice plate including two
tracks, a control track and an isolation track. The control track
is spirally formed within the orifice plate, which has an exit and
entrance on either side of the plate. The control track provides
damping to control damping from engine bounce; whereas, the
isolation track controllably provides dynamic rate dip. The
isolation track is formed between an alignment plate and rotatable
track member, each having an exit and entrance, respectively. The
rotatable track member and the alignment plate are sealingly
engaged and affixed to a decoupler and an annular area disposed
about the orifice plate of the powertrain mount. The exit of the
alignment plate is adjacent the decoupler. The rotatable track
member forms a cavity with the molded body of the powertrain mount,
with the entrance exposed to fluid within the cavity for
controlling and minimizing vibrations within the powertrain. The
isolation track has a track length that may be varied by rotation
of the track member and its entrance. Various magnitudes of
disturbance frequencies may be managed and controlled by either the
fixed control track and/or the variable isolation track within the
powertrain mount.
Inventors: |
Bodie, Mark O.; (Dayton,
OH) ; Long, Mark W.; (Bellbrook, OH) ; Tewani,
Sanjiv G.; (Lebanon, OH) |
Correspondence
Address: |
SCOTT A. MCBAIN
DELPHI TECHNOLOGIES, INC.
Legal Staff, Mail Code: 480-410-202
P.O. BOX 5052
Troy
MI
48007
US
|
Assignee: |
DELPHI TECHNOLOGIES INC.
|
Family ID: |
33029727 |
Appl. No.: |
10/408918 |
Filed: |
April 8, 2003 |
Current U.S.
Class: |
267/140.11 ;
267/219 |
Current CPC
Class: |
F16F 13/262 20130101;
F16F 13/107 20130101 |
Class at
Publication: |
267/140.11 ;
267/219 |
International
Class: |
F16F 005/00; F16M
005/00; F16M 007/00; F16F 009/00; F16M 009/00; F16M 011/00; F16F
013/00; F16F 015/00; F16F 007/00; F16F 011/00; B60G 015/00; B60G
013/00 |
Claims
1. A powertrain mount comprising: an orifice plate including a
fixed spiral track and an annular track formed therein, the fixed
spiral track disposed about the orifice plate including an entrance
on a first side of the orifice plate and exit on a second side of
the plate, and the annular track including an annular surface
disposed about the orifice plate; a decoupler positioned adjacent
the annular surface of the annular track; an alignment plate
positioned adjacent the decoupler and the first side of the orifice
plate, the alignment plate including an exit adjacent the
decoupler; and a rotatable member including an entrance formed
therein, the rotatable member rotatably coupled to the alignment
plate defining a variable track between the rotatable member and
the alignment plate, wherein a variable track length is determined
by rotation of the rotatable member.
2. The powertrain mount of claim 1 further comprising a motor
engaged with the rotatable member and adapted to rotate the
rotatable member for changing the length of the variable track, the
motor sealed from the variable track by the alignment plate.
3. The powertrain mount of claim 2 further comprising a containment
plate attached to the orifice plate, the containment plate
retaining the rotatable member against the orifice plate.
4. The powertrain mount of claim 3 further comprising: a motor
assembly operably attached to the rotatable member, the motor
assembly including the motor and an encoder; and a controller
operably coupled to the encoder; wherein the encoder measures an
angular position of the rotatable member and communicates with the
controller, and the controller determines vibration frequencies and
rotates the motor to rotate the rotatable member allowing fluid
flow through the rotatable member entrance, the variable track, and
the alignment plate opening.
5. The powertrain mount of claim 4 wherein the motor rotates the
rotatable member entrance changing the length of the variable track
and engages the decoupler via the alignment plate opening.
6. The powertrain mount of claim 4 wherein the alignment plate
includes a wall adjacent the alignment plate exit, extending from
an upper surface of the alignment plate into the variable
track.
7. The powertrain mount of claim 4 wherein the rotatable member
includes a wall adjacent the rotatable member entrance, extending
from a lower side of the rotatable member into the variable
track.
8. A powertrain mount comprising: an orifice plate including a
fixed spiral track and an annular track formed therein, the fixed
spiral track disposed about the orifice plate including an entrance
on a first side of the orifice plate and exit on a second side of
the plate, and the annular track including an annular surface
disposed about the orifice plate; a decoupler positioned adjacent
the annular surface of the annular track; an alignment plate
positioned adjacent the decoupler and the first side of the orifice
plate, the alignment plate including an exit adjacent the
decoupler; means for forming a variable track; and means for
changing a variable track length and controlling fluid flow through
the variable track length based on pre-determined vibration
frequencies within the powertrain mount.
9. A powertrain mount comprising: a base plate connected to a
molded member defining a cavity; an orifice plate connected to one
of the base plate or the molded member wherein the orifice plate
spans the cavity defining a primary chamber and a secondary
chamber, the orifice plate including a fixed track and an annular
track formed therein, the fixed track spiralingly disposed about
the orifice plate having an entrance on a first side of the orifice
plate and exit on a second side of the orifice plate, and the
annular track having an annular surface disposed about the orifice
plate; a decoupler disposed about the annular surface of the
annular track; an alignment plate sealingly formed about the
decoupler and the first side of the orifice plate, the alignment
plate including an exit adjacent the decoupler; a rotatable member
rotatably coupled to the alignment plate and adjacent to the first
side of the orifice plate, defining a variable track between the
rotatable member and the alignment plate, the rotatable member
including an entrance formed therein; a containment plate attached
to the orifice plate retaining the rotatable member against the
orifice plate; and a motor engaged with the rotatable member and
adapted to rotate the rotatable member.
10. The powertrain mount of claim 9 further comprising: an encoder
operably attached to the motor for measuring and communicating an
angular position of the rotatable member; and a controller operably
coupled to the encoder; wherein the controller determines vibration
disturbance frequencies and communicates with the encoder to
activate the motor to rotate the rotatable member to allow fluid
flow into the rotatable member entrance, the variable track, and
the orifice plate opening exit.
11. The powertrain mount of claim 10 wherein the alignment plate
includes a wall adjacent the alignment plate exit extending into
the variable track.
12. The powertrain mount of claim 10 wherein the rotatable member
includes a wall adjacent the rotatable member entrance extending
into the variable track.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to powertrain mounts for motor
vehicles, and more particularly to a powertrain mount having a
controllable compliant member.
BACKGROUND OF THE INVENTION
[0002] It is desirable to provide motor vehicles with improved
operating smoothness by damping and/or isolating powertrain
vibrations of the vehicle. A variety of mount assemblies are
presently available to inhibit such engine and transmission
vibrations. Hydraulic mount assemblies of this type typically
include a reinforced, hollow rubber body that is closed by a
resilient diaphragm so as to form a cavity. This cavity is
separated into two chambers by a plate. A first or primary chamber
is formed between the orifice plate and the body, and a secondary
chamber is formed between the plate and the diaphragm.
[0003] The chambers may be in fluid communication through a
relatively large central passage in the plate, and a decoupler may
be positioned in the central passage of the plate disposed about
the passage to reciprocate in response to the vibrations. The
decoupler movement alone accommodates small volume changes in the
two chambers. When, for example, the decoupler moves in a direction
toward the diaphragm, the volume of the portion of the decoupler
cavity in the primary chamber increases and the volume of the
portion in the secondary chamber correspondingly decreases, and
vice-versa. In this way, for certain small vibratory amplitudes and
generally higher frequencies, fluid flow between the chambers is
substantially avoided and undesirable hydraulic damping is
eliminated. In effect, the decoupler is a passive tuning
device.
[0004] As an alternative or in addition to the relatively large
central passage, an orifice track is normally provided. The orifice
track has a relatively small, restricted flow passage extending
around the perimeter of the orifice plate. Each end of the track
has an opening, with one opening communicating with the primary
chamber and the other with the secondary chamber. The orifice track
provides the hydraulic mount assembly with another passive tuning
component, and when combined with the decoupler, provides at least
three distinct dynamic operating modes. The particular operating
mode is primarily determined by the flow of fluid between the two
chambers.
[0005] More specifically, small amplitude vibrating input, such as
from relatively smooth engine idling or the like, produces no
damping due to the action of the decoupler, as explained above. In
contrast, large amplitude vibrating inputs, such as large
suspension inputs, produce high velocity fluid flow through the
orifice track, and an accordingly high level of damping force and
desirable control and smoothing action. A third or intermediate
operational mode of the mount occurs during medium amplitude inputs
experienced in normal driving and resulting in lower velocity fluid
flow through the orifice track. In response to the decoupler
switching from movement in one direction to another in each of the
modes, a limited amount of fluid can bypass the orifice track by
moving around the edges of the decoupler, smoothing the
transition.
[0006] Prior decoupled powertrain mount designs therefore employ a
decoupler that is dependent of vibration amplitudes/frequencies
during compressions of the mount during fluid flow through the
orifice plate. In some vehicle states, such as high-speed shake, it
is advantageous to provide damping for small amplitude vibrations.
During high-speed shake conditions, small imbalances in the
vehicle's wheels excite the powertrain, which result in vibrations
inside the cabin of the vehicle. By controlling the powertrain,
providing damping, the vibrations inside the cabin of the vehicle
are reduced.
[0007] For small mount displacements the dynamic stiffness of the
mount is approximately the same as the static stiffness of the
mount. Ideally, for isolation functions of a powertrain mount, the
dynamic rate at the disturbance frequency should be as low as
possible. Therefore, it is also desirable to lower the dynamic rate
of the mount below a static rate of the mount at engine disturbance
frequencies.
[0008] Prior powertrain designs also incorporate the use of a
single orifice track to control both isolation and damping
functions. Such designs require the powertrain mount to change
between functions when some engine and environment conditions
require both functions simultaneously. For example, a single-track
orifice plate must change from bounce control (at around 10 Hz) to
isolation (which starts at approximately 20 Hz).
[0009] It is desirable, therefore, to provide a powertrain mount
that overcomes these and other disadvantages.
SUMMARY OF THE INVENTION
[0010] The present invention is a powertrain mount comprising an
orifice plate including two tracks, a control track and an
isolation track. The control track includes a fixed spirally formed
track within the orifice plate, which has an exit and entrance on
either side of the plate. The isolation track is formed between an
alignment plate and rotatable track member, each having an exit and
entrance respectively. The rotatable member and the alignment plate
are sealingly engaged and affixed to a decoupler and an annular
area disposed about the orifice plate of the powertrain mount. The
exit of the alignment plate is adjacent the decoupler. The
rotatable member with the orifice plate forms a cavity with a
molded body of the powertrain mount, with the entrance of the
rotatable member exposed to fluid within the cavity for controlling
and minimizing vibrations within the powertrain. The isolation
track has a track length that may be varied by rotation of the
track member and its entrance. Various magnitudes of disturbance
frequencies may be managed and controlled by either the fixed
control track and/or the variable isolation track within the
powertrain mount.
[0011] Accordingly one aspect of the invention includes rotation of
the rotatable member and its entrance changes the length of the
variable track. A motor operably connected and adapted to the
rotatable member to rotate the rotatable member based on vibration
frequencies. Rotation of the rotatable member changes the length of
the variable track and allows fluid flow through the entrance of
the rotatable member, along the isolation track, and to the
decoupler via the exit of the alignment plate.
[0012] Another aspect of the present invention is to provide a
powertrain mount of the type described above that improves
isolation and damping of the mount at particular vibration
disturbance frequencies. Still another aspect of the present
invention is to provide a powertrain mount of the type described
above in which specific ranges of amplitude frequencies of the
powertrain are isolated or damped by selectively rotating the
rotatable member to engage the decoupler member within the
isolation track, while the control track passively controls other
discreet vibrations.
[0013] The foregoing and other features and advantages of the
invention will become further apparent from the following detailed
description of the presently preferred embodiments, read in
conjunction with the accompanying drawings. The detailed
description and drawings are merely illustrative of the invention
rather than limiting, the scope of the invention being defined by
the appended claims and equivalents thereof.
BRIEF DESCRIPTION OF THE DRAWING
[0014] FIG. 1 is an exploded perspective view of a powertrain mount
according to the present invention for a motor vehicle;
[0015] FIG. 2 is a top perspective view of an orifice plate
including a control track and an isolation track in accordance with
the present invention;
[0016] FIG. 3 is a side perspective view cut at section B-B of an
orifice plate including a control track and an isolation track in
accordance with the present invention; and
[0017] FIG. 3a is another side perspective view cut at section A-A
of an orifice plate including a control track and an isolation
track in accordance with the present invention
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0018] FIG. 1 shows an improved hydraulic mount assembly 10
according to the present invention. The mount assembly 10 is
particularly adapted for mounting an internal combustion engine
and/or transmission to a frame in a motor vehicle. The mount
assembly 10 includes a metal base plate 12 and a molded body 14.
The molded body 14 has an elastomeric portion molded around a metal
substrate, and includes a plurality of studs 16 projecting
outwardly to attach the molded body to the engine or transmission.
The base plate 12 is similarly equipped with a plurality of
outwardly projecting studs 17 to attach the base plate to the
frame.
[0019] The base plate 12 and the molded body 14 are configured and
joined to form a hollow cavity for receiving a damping liquid such
as a glycol fluid. An elastomeric diaphragm 18 of natural or
synthetic rubber is attached around its perimeter to the base plate
12 and/or to the body 14, and extends across the cavity. The
diaphragm 18 may include an annular rim section having a radially
inwardly facing internal groove formed between upper and lower
shoulders such as is described in U.S. Pat. No. 5,263,693, the
disclosure of which is hereby incorporated by reference. The
shoulders are normally flexible so as to sealingly receive the
periphery of a die-cast metal or plastic orifice plate 20.
[0020] The orifice plate 20 spans the cavity to define a primary
chamber and a secondary chamber, as is well known. The orifice
plate 20 includes a fixed spiraling track 30, best seen in FIG. 2,
and an isolation track 40 that is generally within the same plane
as the control track. Control track 30 has entrance 32 and exit 34
on either side of orifice plate 20. Track 30 may include varying
degrees of traversing slope from entrance 32 to exit 34 (e.g.
gradual or aggressive). Isolation track 40 has an entrance 42 and
an exit 44. In one embodiment, wall extension 46 blocks fluid from
directly flowing from variable track entrance 42 to the exit 44,
promoting flow along the isolation track 40.
[0021] Referring now to FIG. 3, control track entrance 32 is shown
on first side 22 of orifice plate 20, with the control track exit
34 on a second side 24 of fixed track 30. Isolation track 40 is
formed by a rotatable member 60 sealingly engaged and adjacent to a
alignment plate 50 which are both held against the orifice plate
20. Alignment plate 50 is disposed about annular surface 26 and the
first side 22 of orifice plate 20, and adjacent to decoupler 70.
Similarly, decoupler 70 is disposed about the annular surface 26 of
the orifice plate 20. The alignment plate includes an exit 44, as
seen in FIGS. 2 and 3, which exposes decoupler 70 to fluid within
the powertrain mount 10. Alignment plate exit 44 therefore engages
decoupler 70 by exposing fluid to the decoupler 70 at the end of
isolation track 40. Rotatable member 60 includes entrance 42 for
fluid flow from the chamber formed from the molded body 14 and the
orifice plate 20 (best shown in FIGS. 1 and 2). In another
embodiment of the invention, wall 46 extends from lower surface of
rotatable member 60 into the variable track, preventing direct
fluid flow from entrance 42 to exit 44. In yet another embodiment,
wall 46 extends from the alignment plate 50 similarly blocking
direct fluid flow from entrance 42 to exit 44, and forcing flow
along the length of the variable track 40, best seen in FIG. 3a.
Wall 46 extends from either the bottom side of the rotatable member
60 or the from the alignment plate 50 to force fluid flow through
the entrance 42 of the rotatable member 60, along the variable
isolation track, and through the exit 44 to the exposed decoupler
70, blocking fluid from directly flowing from the entrance 42 to
the exit 44.
[0022] Referring back to FIG. 1, rotatable member 60 is held
against orifice plate and in close proximity to alignment plate 50
by a containment plate 80. An inside diameter 82 of the containment
plate 80 is sized to be closely received over legs 62 of the track
member, while an outside diameter 84 of the containment plate 80 is
affixed to the orifice plate 20. Thus, isolation track 40 may be
generally structured by rotatable member entrance 42 with track
formed by alignment plate 50 and rotatable member 60 and exit 44
exposing the decoupler 70.
[0023] In operation of one embodiment of the present invention,
rotation of the rotatable member 60 changes the length of the
isolation track 40. Rotation may be performed with a motor assembly
90, which includes motor 92 and encoder 94. The motor assembly 90
is operably connected to the rotatable member 60 and is sealed off
from the two tracks 30 and 40. The motor assembly 90 is operably
connected to a controller (not shown), and is sealed from operation
of the isolation track. The encoder 94 or similar device measures
an angular position of the rotatable member 60 and communicates
with the controller. The controller determines vibration
frequencies and rotates the motor to rotate the rotatable member 60
changing the length of the variable track 40 and allowing fluid
flow through the entrance of the rotatable member 42, along the
isolation track, and to the decoupler 70 via the exit 44 of the
alignment plate 50. A dynamic rate dip occurs as a function of
resonate frequency of the fluid in the track, which generally is a
function of track length and area (i.e., freq .about.Length/Area).
The controller may receive one or more signals from a powertrain
control module (not shown), such as r.p.m., to activate and rotate
the motor and the track member entrance 42 to change the length of
the isolation track 40, tracking engine disturbance frequencies and
adjusts accordingly. Thus, the isolation track 40 operates to
manage and control dynamic rate dip of engine operation, such as
operational moments of force and other vibrations, to reduce the
dynamic rate dip and reduce the stiffness of the mount 10 to
further improve powertrain isolation.
[0024] Control track 30 performs as a passive track as it is fixed
in length, continually operating to manage and control engine
bounce or other various forms of road and environment input. Within
the present invention, both the isolation track 40 and the control
track 30 may be used simultaneously for wider range engine
vibration disturbance frequencies. For example, in one embodiment
of the invention, isolation track resonance starts at engine
disturbance frequencies of 20 Hz or higher in the dual track
orifice mount, allowing for higher ending resonance frequency. For
large displacements across the mount, the decoupler 70 within the
isolation track 40 is maximized (i.e., bottoms out), and forces
fluid to flow into the control track 30, which provides damping to
control the engine. Within the present invention, two orifice
tracks are provided; the control track 30 to provide damping and a
controllable isolation track 40 to provide a dynamic rate dip. As
such, the present invention, includes, but is not limited to, the
benefits of increasing the frequency range of the dynamic rate dip,
and providing a dynamic rate dip in driving as well as idle
conditions.
[0025] While the embodiments of the invention disclosed herein are
presently considered to be preferred, various changes and
modifications can be made without departing from the spirit and
scope of the invention. The scope of the invention is indicated in
the appended claims, and all changes that come within the meaning
and range of equivalents are embraced therein.
* * * * *