U.S. patent application number 13/201526 was filed with the patent office on 2011-12-22 for stator and torque converter.
This patent application is currently assigned to EXEDY CORPORATION. Invention is credited to Nobuyoshi Shiomura, Tomohiro Tasaka.
Application Number | 20110311367 13/201526 |
Document ID | / |
Family ID | 45328841 |
Filed Date | 2011-12-22 |
United States Patent
Application |
20110311367 |
Kind Code |
A1 |
Shiomura; Nobuyoshi ; et
al. |
December 22, 2011 |
STATOR AND TORQUE CONVERTER
Abstract
It is an object of the present invention to inhibit generation
of a vortex in the position where operating oil separates from a
stator and to increase a capacity coefficient by allowing the
operating oil to efficiently flow from a turbine to an impeller. A
torque converter stator of the present invention is configured to
regulate the flow of operating oil returning from a turbine to an
impeller within a torque converter. The torque converter stator
includes an annular stator shell, a plurality of stator blades and
an annular stator core. The stator blades are radially extended
from the stator shell. The stator blades respectively include a
corrugated operating-oil outlet-side edge. The stator core is
disposed on the outer peripheries of the stator blades.
Inventors: |
Shiomura; Nobuyoshi;
(Knoxville, TN) ; Tasaka; Tomohiro; ( Hyogo,
JP) |
Assignee: |
EXEDY CORPORATION
Neyagawa-shi, Osaka
JP
|
Family ID: |
45328841 |
Appl. No.: |
13/201526 |
Filed: |
February 4, 2010 |
PCT Filed: |
February 4, 2010 |
PCT NO: |
PCT/JP2010/059740 |
371 Date: |
August 15, 2011 |
Current U.S.
Class: |
416/223R |
Current CPC
Class: |
F16H 41/26 20130101 |
Class at
Publication: |
416/223.R |
International
Class: |
F01D 5/14 20060101
F01D005/14 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2009 |
JP |
2009-033618 |
Claims
1. A torque converter stator configured to regulate flow of an
operating oil returning from a turbine to an impeller within a
torque converter, the torque converter stator comprising: an
annular shell; first and second blades configured around the
annular shell and radially extending from the annular shell, the
first blade extending in a first direction, the first blade
including a first operating-oil outlet-side edge, the second blade
including a second operating-oil outlet-side edge, the first and
second blades being corrugated; and a first annular core disposed
on an outer periphery of the first blade and an outer periphery of
the second blade.
2. The torque converter stator recited in claim 1, wherein the
first blade including a first concave being recessed in a second
direction which is perpendicular to the first direction.
3. The torque converter stator recited in claim 1, wherein the
first blade including a first convex bulging in a third direction
opposite to the second direction.
4. The torque converter stator recited in claim 1, wherein a ratio
of a height h to a width H is in a range of 3 to 20%, where the
height h is between a tip of the first convex and a bottom of the
first concave, and the width H is a length in a longitudinal
direction of the first blade.
5. A torque converter configured to transmit torque from an engine
to a transmission via a fluid, the torque converter comprising: an
impeller configured to receive the torque inputted from the engine;
a turbine configured opposite to the impeller, the turbine
configured to output the torque to the transmission; and a stator
disposed between an inner radial part of the impeller and an inner
radial part of the turbine, the stator including: an annular shell,
first and second blades radially configured around the annular
shell and extending from the annular shell, the first blade
extending in a first direction, the first blade including a first
operating-oil outlet-side edge, the second blade including a second
operating-oil outlet-side edge, the first and second blades being
corrugated, and a first annular core disposed on an outer periphery
of the first blade and an outer periphery of the second blade.
6. The torque converter recited in claim 5, wherein the first blade
includes a first concave being recessed in a second direction which
is perpendicular to the first direction.
7. The torque converter recited in claim 5, wherein the first blade
including a first convex bulging in a third direction opposite to
the second direction.
8. The torque converter recited in claim 5, wherein a ratio of
height h and a width H is in a range of 3 to 20%, where the height
h is between a tip of the first convex and a bottom of the first
concave, and the width H is a length in a longitudinal direction of
the first blade.
Description
CROSS-REFERENCE TO THE RELATED APPLICATIONS
[0001] This U.S. National stage application claims priority under
35 U.S.C. .sctn.119(a) to Japanese Patent Application No.
2009-033618 filed in Japan on Feb. 17, 2009. The entire disclosure
of Japanese Patent Application No. 2009-033618 is hereby
incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a stator, particularly to a
stator for regulating flow of operating oil returning from a
turbine to an impeller within a torque converter. Further, the
present invention relates to a torque convertor, particularly to a
torque convertor for transmitting torque from an engine to a
transmission via fluid.
BACKGROUND ART
[0003] The torque convertors generally include a front cover, an
impeller, a turbine, and a stator. Torque is transmitted from the
engine to the front cover. The torque transmitted to the front
cover is subsequently transmitted to the impeller. When power is
transmitted to the impeller, the impeller is rotated and operating
oil is moved to the turbine. The turbine is rotated by the
operating oil moved thereto. Torque is herein transmitted from the
turbine to a transmission-side shaft and the transmission-side
shaft is accordingly rotated. The operating oil residing in the
turbine is then returned to the impeller through the stator.
[0004] The stator is herein a mechanism configured to regulate flow
of the operating oil returning to the impeller from the turbine.
The stator is disposed between the inner radial part of the
impeller and that of the turbine. The stator mainly includes an
annular stator shell, a plurality of stator blades disposed on the
outer peripheral surface of the stator shell, and an annular stator
core fixed to the tips of the plural stator blades. The stator
shell is supported by a stationary shaft through a one-way clutch
(Patent Literature 1).
[0005] Japan Laid-open Patent Application Publication No.
JP-A-2001-355701 (Patent Literature 1) is an example of the related
art.
SUMMARY
Technical Problems
[0006] Here, focusing on the fluid flow in the vicinity of the
stator within the well-known torque converters as described in
Patent Literature 1, the operating oil separates from the blades of
the stator at the fluid outlet of the blades and its periphery. A
vortex is herein generated in the downstream (i.e., the impeller
side) of the blades. When the vortex is thus generated, the
transmission loss is increased in the torque transmission capacity
by the operating oil. The capacity coefficient of the torque
converter is thereby reduced, and the torque transmission
efficiency is deteriorated.
[0007] It is an object of the present invention to inhibit
generation of a vortex in the position where the operating oil
separates from the stator and to increase the capacity coefficient
by allowing the operating oil to efficiently flow from the turbine
to the impeller.
Solution to Problems
[0008] A torque converter stator according to a first aspect of the
present invention is configured to regulate the flow of an
operating oil returning from a turbine to an impeller within a
torque converter. The torque converter stator includes an annular
shell, a plurality of blades, and an annular core. The blades
radially extend from the annular shell. Each of the blades includes
a corrugated operating-oil outlet-side edge. The core is disposed
on the outer peripheries of the blades.
[0009] According to the torque converter stator of the first aspect
of the present invention, the outlet-side edge of each blade has a
corrugated shape. Therefore, the flow rate of the operating oil
will be irregular on the outlet-side of each blade. Therefore, not
a large vortex but a number of relatively small vortices are herein
generated unlike the well-known stator. In addition, the plural
vortices act to cancel out each other. Therefore, it is possible to
inhibit efficiency reduction due to generation of vortices.
[0010] A torque converter stator according to a second aspect of
the present invention relates to the torque converter stator
according to the first aspect of the present invention. In the
torque converter stator, each of the blades includes a plurality of
concaves on the operating-oil outlet-side edge. Each of the
concaves is recessed in a blade transverse direction with respect
to an imaginary straight line connecting a shell-side end and a
core-side end in the respective blades. According to the torque
converter stator of the second aspect of the present invention, it
is possible to achieve the same advantageous effect as that
achieved by the torque converter stator of the first aspect of the
present invention.
[0011] A torque converter stator according to a third aspect of the
present invention relates to the torque converter stator according
to the first aspect of the present invention. In the torque
converter stator, each of the blades includes a plurality of
convexes on the operating-oil outlet-side edge. The convexes
protrudes in a blade transverse direction with respect to an
imaginary straight line connecting a shell-side end and a core-side
end in the respective blades. According to the torque converter
stator of the third aspect of the present invention, it is possible
to achieve the same advantageous effect as that achieved by the
torque converter stator of the first aspect of the present
invention.
[0012] A torque converter stator according to a fourth aspect of
the present invention relates to the torque converter stator
according to one of the first to third aspects of the present
invention. In the torque converter stator, the corrugated shape of
the respective blades is formed by setting a ratio of an entire
concave/convex height h with respect to an entire radial width H to
be in a range of 3 to 20%.
[0013] A torque converter according to a fifth aspect of the
present invention is configured to transmit torque from an engine
to a transmission via a fluid. The torque converter includes an
impeller, a turbine, and a stator. The impeller is configured to
receive the torque inputted from the engine. The turbine is
opposite to the impeller while being allowed to output torque to
the transmission. The stator is related to the stator according to
one of the first to fourth aspects of the present invention. The
stator is disposed between an inner radial part of the impeller and
an inner radial part of the turbine.
Advantageous Effects of the Invention
[0014] According to the aforementioned present invention,
generation of an enormous vortex can be inhibited in the position
where the operating oil separates from the stator, and the capacity
coefficient can be thereby increased.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic vertical cross-sectional view of a
torque converter as an exemplary embodiment of the present
invention.
[0016] FIG. 2 is a partial front view of a stator.
[0017] FIG. 3 is a partial external perspective view of the
stator.
[0018] FIG. 4 is a chart showing a characteristic comparison
between a torque converter using stator blades of the exemplary
embodiment of the present invention and a well-known torque
converter.
[0019] FIG. 5 is a diagram illustrating a stator blade of another
exemplary embodiment of the present invention.
DESCRIPTION OF THE EMBODIMENTS
[0020] [Basic Structure of Torque Converter]
[0021] FIG. 1 is a schematic vertical cross-sectional view of a
torque converter 1 adopting an exemplary embodiment of the present
invention. The torque converter 1 is a device configured to
transmit torque from a crankshaft (not illustrated in the figure)
of an engine to an input shaft (not illustrated in the figure) of a
transmission. The engine (not illustrated in the figure) is
disposed on the left side in FIG. 1 whereas the transmission (not
illustrated in the figure) is disposed on the right side of FIG. 1.
A line O-O depicted in FIG. 1 is the rotation axis of the torque
converter 1.
[0022] The torque converter 1 includes a torus 5 formed by three
types of blade wheels (i.e., an impeller 2, a turbine 3, and a
stator 4), and a lock-up device 6.
[0023] A front cover 10 is a disc member disposed closer to the tip
of the engine crankshaft. A center boss 11 is welded to the inner
radial part of the front cover 10. A plurality of nuts 12 is fixed
to the outer radial part of the engine-side surface of the front
cover 10, while being circumferentially disposed at equal
intervals.
[0024] The front cover 10 includes an outer peripheral tubular
portion 13 on the outer periphery thereof. The outer peripheral
tubular portion 13 axially extends towards the transmission. The
outer peripheral edge of an impeller shell 15 of the impeller 2 is
welded to the tip of the outer peripheral tubular portion 13.
Consequently, the front cover 10 and the impeller 2 form a fluid
chamber that operating oil (fluid) is filled in the interior
thereof.
[0025] The impeller 2 mainly includes the impeller shell 15, a
plurality of impeller blades 16, and an impeller hub 17. The
impeller blades 16 are fixed to the inside of the impeller shell
15. The impeller hub 17 is fixed to the inner radial part of the
impeller shell 15. An annular impeller core 18 is fixed to the
inner edges of the plural impeller blades 16. Each impeller blade
16, which is formed in a circular-sector shape, has a
crescent-shaped center part. Therefore, the cross-sectional shape
of the impeller core 18 is matched with the shape of the center
part of each impeller blade 16.
[0026] The turbine 3 is axially opposite to the impeller 2 within
the fluid chamber. The turbine 3 includes a turbine shell 20, a
plurality of turbine blades 21, a turbine core 22, and a turbine
hub 23. The turbine shell 20 is an annular member that the inner
radial part thereof is welded to turbine hub 23. The turbine blades
21 are fixed to the inside of the turbine shell 21. The plural
turbine blades 21 are circumferentially aligned. The turbine core
22 is disposed on the tips (inner edges) of the turbine blades 21.
The turbine hub 23 is attached onto a transmission-side shaft while
being prevented from rotating relative to the transmission-side
shaft. The turbine hub 23 includes a tubular portion 23a, and a
disc flange 23b. The tubular portion 23a is disposed on the outer
peripheral side of the transmission-side shaft. The flange 23b
radially protrudes outwards from a substantially axial center part
of the tubular portion 23a.
[0027] The stator 4 is a mechanism configured to regulate flow of
the operating oil returning from the turbine 3 to the impeller 2.
The stator 4 is a member integrally formed by casting of resin,
aluminum alloy or the like. The stator 4 is disposed between the
inner radial part of the impeller 2 and that of the turbine 3. The
stator 4 mainly includes an annular stator shell 25, a plurality of
stator blades 26 and an annular stator core 27. The plural stator
blades 26 are disposed on the outer peripheral surface of the
stator shell 25. The stator core 27 is fixed to the tips of the
plural stator blades 26. The stator shell 25 is supported by a
stationary shaft (not illustrated in the figure) through a one-way
clutch 30. Further, a retainer 31 is disposed on the axial engine
side of the one-way clutch 30. The retainer 31 holds the one-way
clutch 30 while being disposed between the one-way clutch 30 and
the flange 23b of the turbine hub 23. Further, the retainer 31
includes a plurality of radially extended grooves on a surface
thereof that makes contact with the flange 23b. The operating oil
is thereby allowed to flow from the inner peripheral side to the
outer peripheral side.
[0028] A thrust bearing 32 is disposed between the impeller hub 17
and the stator shell 25. Further, a sealing member 33 is disposed
between the inner race of the one-way clutch 30 and the outer
periphery of the tubular portion 23a of the turbine hub 23.
[0029] [Stator Blades]
[0030] Next, the stator blades 26 will be explained in detail with
reference to FIGS. 2 to 4. As illustrated in a partial enlarged
view of FIG. 2, each stator blade 26 is a plate member with a
predetermined width connecting the stator shell 25 and the stator
core 27. Each stator blade 26 includes an inlet-side edge and an
outlet-side edge. The inlet-side edge is formed for linearly
connecting a shell-side end S1 and a core-side end C1. On the other
hand, the outlet-side edge is not formed for connecting a
shell-side end S2 and a core-side end C2 by an imaginary straight
line M. The outlet-side edge includes three concaves 26a recessed
transversely inwards (towards the inlet) with respect to the
imaginary straight line M. Each concave 26a is recessed in a
circular-arc shape. In other words, each stator blade 26 includes
two convexes 26b on the outlet-side edge. Each convex 26b is
tapered along the flow direction of the operating oil. Thus, the
outlet-side edge includes concaves/convexes in the blade transverse
direction and is thereby formed in a corrugated shape.
[0031] The concaves 26a and the convexes 26b are not herein formed
due to manufacturing errors but formed purposefully. In FIG. 2, the
length h of each concave 26a (i.e., the height of each convex 26b)
is herein preferably set to be in a range of 3 to 20% of the length
H of an imaginary straight line connecting the shell-side end S2
and the core-side end C2 (i.e., the entire radial width).
[0032] [Lock-up Device]
[0033] Next, the lock-up device 6 will be explained. The lock-up
device 6 mainly includes a piston 40 and a damper mechanism 41.
[0034] The piston 40 is a disc member disposed between the front
cover 10 and the turbine 3. An inner peripheral tubular portion 42
is formed in the inner periphery of the piston 40 while being
axially extending towards the transmission. The inner peripheral
tubular portion 42 is supported on the outer peripheral surface of
the turbine hub 23 while being rotatable relative to the turbine
hub 23 and axially movable. It should be noted that the axial
transmission-side end of the inner peripheral tubular portion 42 is
abutted to the flange 23b of the turbine hub 23 and the inner
peripheral tubular portion 42 is restricted from axially moving
towards the transmission up to a predetermined position. A sealing
ring 43 is disposed on the outer peripheral surface of the turbine
hub 23. The sealing ring 43 seals axial adjacent spaces in the
inner periphery of the piston 40.
[0035] The outer radial part of the piston 40 functions as a clutch
coupling portion. In other words, an annular friction facing 45 is
fixed to the engine-side surface of the outer radial part of the
piston 40. The friction facing 45 is opposite to an annular flat
friction surface formed on the inner surface of the outer radial
part of the front cover 10.
[0036] The damper mechanism 41 includes a retaining plate 46, a
driven plate 47, and a plurality of torsion springs 48. The
retaining plate 46 is fixed to the turbine 3 side surface of the
outer radial part of the piston 40 by a plurality of rivets 49. The
retaining plate 46 includes cut-and-bent portions for accommodating
and supporting the torsion springs 48. The plural torsion springs
48 are circumferentially extended coil springs. The torsion springs
48 are accommodated in the retaining plate 46 while the both
circumferential ends thereof are supported. The driven plate 47 is
an annular plate fixed to the outer radial part of the turbine
shell 20 of the turbine 3. The driven plate 47 extends towards the
front cover 10. The driven plate 47 includes protruded claws 47a to
be engaged with the both circumferential ends of the respective
torsion springs 48.
[0037] [Actions]
[0038] Torque is transmitted from the crankshaft of the engine (not
illustrated in the figures) to the front cover 10 and the impeller
2. The operating oil is driven by the impeller blades 16 of the
impeller 2 and thereby rotates the turbine 3. Rotation of the
turbine 3 is outputted to the input shaft of the transmission (not
illustrated in the figures) through the turbine hub 23. In flowing
from the turbine 3 to the impeller 2, the operating oil flows to
the impeller 2 through a path defined by the stator shell 25 and
the stator core 27 of the stator 4.
[0039] When the operating oil passes through the stator 4, the
stator blades 26 restrict the flow of the operating oil. The
operating oil separates from the stator blades 26 at the
outlet-side edges of the stator blades 26. The outlet-side edge of
each stator blade 26 herein includes a plurality of
concaves/convexes, and is thereby formed in a corrugated shape.
Accordingly, the flow rate of the operating oil is irregular in a
flow direction from the outlet-side edge to the impeller 2. In
other words, the flow rate of the operating oil varies in
accordance with the concaves/convexes forming the corrugated shape.
Therefore, relatively small vortices are irregularly generated
while a large vortex, which is generated in the well-known stator
blades, is not easily generated. As a result, thus generated
vortices cancel out each other.
[0040] With the corrugated outlet-side edges of the stator blades
26, it is thus possible to inhibit generation of a vortex and
inhibit reduction in a capacity coefficient. FIG. 4 shows a
characteristic comparison between the torque converter using the
well-known stator blades and the torque converter using the stator
blades 26 of the present exemplary embodiment. In FIG. 4,
characteristics of the present exemplary embodiment are depicted
with a solid line, whereas characteristics of the well-known torque
converter are depicted with a broken line. More specifically, the
following characteristics are set for the present exemplary
embodiment and the well-known torque converter. As to the present
exemplary embodiment, a capacity coefficient is set as a
characteristic Cc1; a torque ratio is set as a characteristic T1;
and a torque transmission efficiency is set as a characteristic
.eta.1. As to the well-known torque converter, a capacity
coefficient is set as a characteristic Cc2; a torque ratio is set
as a characteristic T2; and a torque transmission coefficient is
set as a characteristic .eta.2.
[0041] As is obvious from FIG. 4, the torque converter using the
stator blades 26 of the present exemplary embodiment can increase
the capacity coefficient while keeping the efficiency roughly at
the same level as that of the well-known torque converter.
[0042] When the operating oil residing in the space between the
front cover 10 and the piston 40 is herein drained from the inner
peripheral side, the piston 40 is moved towards the front cover 10
by a hydraulic difference and the friction facing 45 is pressed
onto the friction surface of the front cover 10. Consequently,
torque is directly transmitted from the front cover 10 to the
turbine hub 23 through the lock-up device 6.
Other Exemplary Embodiments
[0043] The present invention is not limited to the aforementioned
exemplary embodiment. A variety of changes or modifications can be
herein made without departing from the scope of the present
invention.
[0044] FIG. 5 illustrates one of stator blades of another exemplary
embodiment. Each stator blade 26' herein includes a plurality of
convexes 26b' on the outlet-side edge thereof. Each convex 26b'
protrudes transversely outwards with respect to an imaginary line M
connecting a shell-side end S2 and a core-side end C2 in each
stator blade 26'. Each convex 26b' is tapered along the flow
direction of the operating oil. Further, concaves 26a' are formed
for alternately aligning with the convexes 26b'. Accordingly, the
outlet-side edge of each stator blade 26' has an entirely
corrugated shape.
INDUSTRIAL APPLICABILITY
[0045] According to the aforementioned present invention,
generation of an enormous vortex can be inhibited in the position
where the operating oil separates from the stator, and a capacity
coefficient can be thereby increased.
General Interpretation of Terms
[0046] In understanding the scope of the present invention, the
term "comprising" and its derivatives, as used herein, are intended
to be open ended terms that specify the presence of the stated
features, elements, components, groups, integers, and/or steps, but
do not exclude the presence of other unstated features, elements,
components, groups, integers and/or steps. The foregoing also
applies to words having similar meanings such as the terms,
"including", "having" and their derivatives. Also, the terms
"part," "section," "portion," "member" or "element" when used in
the singular can have the dual meaning of a single part or a
plurality of parts. Finally, terms of degree such as
"substantially", "about" and "approximately" as used herein mean a
reasonable amount of deviation of the modified term such that the
end result is not significantly changed. For example, these terms
can be construed as including a deviation of at least .+-.5% of the
modified term if this deviation would not negate the meaning of the
word it modifies.
[0047] While only selected embodiments have been chosen to
illustrate the present invention, it will be apparent to those
skilled in the art from this disclosure that various changes and
modifications can be made herein without departing from the scope
of the invention as defined in the appended claims. Furthermore,
the foregoing descriptions of the embodiments according to the
present invention are provided for illustration only, and not for
the purpose of limiting the invention as defined by the appended
claims and their equivalents.
* * * * *