U.S. patent application number 13/950859 was filed with the patent office on 2014-03-20 for launch torus torque converter.
This patent application is currently assigned to GM Global Technology Operations LLC. The applicant listed for this patent is GM Global Technology Operations LLC. Invention is credited to Jean M. Schweitzer, Shijian Zhou.
Application Number | 20140079570 13/950859 |
Document ID | / |
Family ID | 50274670 |
Filed Date | 2014-03-20 |
United States Patent
Application |
20140079570 |
Kind Code |
A1 |
Schweitzer; Jean M. ; et
al. |
March 20, 2014 |
LAUNCH TORUS TORQUE CONVERTER
Abstract
A torque converter having an impeller, a turbine, and a stator
disposed between the impeller and the turbine is provided. The
torque converter has an axially thin design, with a torus width to
torque converter diameter ratio of about 0.15 to 0.17, by way of
example. In some variations, the stator has twisted blades that
have lower shell blade angles than core blade angles with respect
to the center line of torque converter flow, at both the inlet and
outlet.
Inventors: |
Schweitzer; Jean M.;
(Waterford, MI) ; Zhou; Shijian; (Rochester Hills,
MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM Global Technology Operations LLC |
Detroit |
MI |
US |
|
|
Assignee: |
GM Global Technology Operations
LLC
Detroit
MI
|
Family ID: |
50274670 |
Appl. No.: |
13/950859 |
Filed: |
July 25, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61702033 |
Sep 17, 2012 |
|
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|
Current U.S.
Class: |
417/364 |
Current CPC
Class: |
F04D 13/02 20130101;
F16H 41/26 20130101 |
Class at
Publication: |
417/364 |
International
Class: |
F04D 13/02 20060101
F04D013/02 |
Claims
1. A torque converter for a motor vehicle, the torque converter
comprising: an impeller member configured to be driven
hydraulically by a prime mover of the motor vehicle; a turbine
member configured to receive fluid energy from the impeller member
and convert the fluid energy to mechanical energy, the turbine
member being disposed opposite the impeller member, the impeller
member and the turbine member cooperating to define a torus width
L.sub.t and a torque converter diameter D; and a stator member
disposed between the impeller member and the turbine member, the
stator member being configured to increase torque multiplication of
the torque converter, wherein the torque converter has a torus
width L.sub.t to torque converter diameter D ratio (L.sub.t/D) in
the range of about 0.15 to about 0.17.
2. The torque converter of claim 1, wherein the stator member has a
plurality of stator blades, the plurality of stator blades
comprising about 20 to about 42 stator blades.
3. The torque converter of claim 2, wherein the impeller member and
the turbine member cooperate to define a torus height d, the torque
converter having an aspect ratio (torus width L.sub.t divided by
torus height d, L.sub.t/d) in the range of about 0.73 to about
0.78.
4. The torque converter of claim 3, wherein the torque converter
has a torus passage height h to torque converter diameter D ratio
(h/D) of about 0.053 to about 0.057.
5. The torque converter of claim 4, wherein the stator member
defines a stator shell radius R.sub.s, the torque converter having
a torus position (2 times the stator shell radius R.sub.s divided
by the torque converter diameter D, 2*R.sub.s/D) in the range of
about 0.55 to about 0.61.
6. The torque converter of claim 5, wherein at least one of the
impeller member and the turbine member defines a torus area ratio
distribution that decreases along a torus length TL of one of the
impeller member and the turbine member by an amount in the range
about 75% to 90%.
7. The torque converter of claim 6, wherein each stator blade
extends at an inlet core stator blade angle .theta. from a center
line C of torque converter flow at a core side of the stator member
and at an inlet side of the stator member; wherein each stator
blade extends at an outlet core stator blade angle .gamma. from a
center line C of torque converter flow at the core side of the
stator member and at an outlet side of the stator member; wherein
each stator blade extends at an inlet shell stator blade angle
.alpha. from a center line C of torque converter flow at a shell
side of the stator member and at the inlet side of the stator
member; wherein each stator blade extends at an outlet shell stator
blade angle .beta. from a center line C of torque converter flow at
the shell side of the stator member and at the outlet side of the
stator member; wherein the inlet shell stator blade angle .alpha.
is less than the inlet core stator blade angle .theta.; and wherein
the outlet shell stator blade angle .beta. is less than the outlet
core stator blade angle .gamma..
8. The torque converter of claim 7, wherein the inlet core stator
blade angle .theta. minus the inlet shell stator blade angle
.alpha. is in the range of about 12.degree. to about 17.degree.;
and wherein the outlet core stator blade angle .gamma. minus the
outlet shell stator blade angle .beta. is in the range of about
9.degree. to about 22.degree..
9. The torque converter of claim 8, wherein each stator blade is
twisted and has a greater two-dimensional length at the shell side
of the stator member than at the core side of the stator
member.
10. The torque converter of claim 9, wherein each stator blade has
a shell length Ls.sub.s at the shell side of the stator member and
each stator blade has a core length Ls.sub.c at the core side of
the stator member, the ratio of the shell length Ls.sub.s to the
core length Ls.sub.c being in the range of about 1.2 to about
1.9.
11. The torque converter of claim 10, wherein the impeller member
has 37 pump blades.
12. The torque converter of claim 11, wherein the turbine member
has 35 turbine blades.
13. The torque converter of claim 1, wherein the torque converter
has a coupling speed ratio in the range of about 0.89 to about
0.90.
14. The torque converter of claim 13, wherein the torque converter
has a retention (K-factor at the coupling speed ratio divided by
K-factor at a stall speed ratio, K.sub.cp/K.sub.s) in the range of
about 1.01 to about 1.10.
15. The torque converter of claim 14, wherein the torus width
L.sub.t to torque converter diameter D ratio (L.sub.t/D) is about
0.16.
16. A torque converter for a motor vehicle, the torque converter
comprising: an impeller member configured to be driven
hydraulically by a prime mover of the motor vehicle; a turbine
member configured to receive fluid energy from the impeller member
and convert the fluid energy to mechanical energy, the turbine
member being disposed opposite the impeller member; and a stator
member disposed between the impeller member and the turbine member,
the stator member being configured to increase torque
multiplication of the torque converter, the stator member having a
plurality of stator blades, wherein each stator blade of the
plurality of stator blades extends at an inlet core stator blade
angle .theta. from a center line C of torque converter flow at a
core side of the stator member and at an inlet side of the stator
member; wherein each stator blade extends at an outlet core stator
blade angle .gamma. from a center line C of torque converter flow
at the core side of the stator member and at an outlet side of the
stator member; wherein each stator blade extends at an inlet shell
stator blade angle .alpha. from a center line C of torque converter
flow at a shell side of the stator member and at an inlet side of
the stator member; wherein each stator blade extends at an outlet
shell stator blade angle .beta. from a center line C of torque
converter flow at the shell side of the stator member and at the
outlet side of the stator member; wherein the inlet shell stator
blade angle .alpha. is less than the inlet core stator blade angle
.theta.; and wherein the outlet shell stator blade angle .beta. is
less than the outlet core stator blade angle .gamma..
17. The torque converter of claim 16, wherein the inlet core stator
blade angle .theta. minus the inlet shell stator blade angle
.alpha. is in the range of about 12-17.degree.; and wherein the
outlet core stator blade angle .gamma. minus the outlet shell
stator blade angle .beta. is in the range of about
9-22.degree..
18. The torque converter of claim 17, wherein each stator blade is
twisted and has a greater two-dimensional length at the shell side
of the stator member than at the core side of the stator.
19. The torque converter of claim 18, wherein each stator blade has
a shell length Ls.sub.s at the shell side of the stator member and
each stator blade has a core length Ls.sub.c at the core side of
the stator member, the ratio of the shell length Ls.sub.s to the
core length Ls.sub.c being in the range of about 1.2 to about
1.9.
20. The torque converter of claim 19, wherein the impeller member
has 37 pump blades, wherein the turbine member has 35 turbine
blades, and wherein the plurality of stator blades comprises about
20-42 stator blades.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/702,033 filed on Sep. 17, 2012. The disclosure
of the above application is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to hydrodynamic drive
mechanisms, and more particularly, to torque converter assemblies
including an impeller, a turbine, and a stator.
BACKGROUND
[0003] The statements in this section merely provide background
information related to the present disclosure and may or may not
constitute prior art.
[0004] Current automatic power transmissions generally include a
hydrodynamic input device such as a torque converter or fluid
coupler. The torque converter automatically disengages the rotating
engine output shaft from the transmission input shaft during
vehicle idle conditions to enable the vehicle to stop without
stalling the engine. The torque converter also functions as a
torque multiplier which increases engine torque delivered to the
transmission in the lower speed range until torque converter output
speed approximately matches the input (engine) speed.
[0005] The torque converter includes three bladed, fan-like wheels:
an engine-driven impeller, a fluid turbine, and a fluid stator. The
impeller driven by the engine accelerates fluid for passage to the
turbine. The turbine converts the fluid energy coming from the
impeller into mechanical energy, which is transmitted to the input
shaft of a transmission. The stator mechanism disposed between the
fluid inlet of the impeller and the fluid outlet of the turbine
redirects the fluid from the turbine to the impeller thereby
improving the flow efficiency and increasing the torque
multiplication of the hydrodynamic torque converter. The fluid
passes from the inner torus section of the impeller substantially
radially outward in a toric path and then through the path in the
turbine in a substantially toric path back to the stator.
[0006] A stator is made up of a plurality of stator blades, which
are connected at one end to a relatively small ring, the inner part
of the shell, and at the other end to a larger ring, the core.
Fluid flowing through the stator passes along the stator blades.
These blades force the fluid to change direction so fluid exiting
the stator enters the pump flowing in the same direction as the
pump is rotating, thereby conserving power.
[0007] One of the measures of torque converter performance is the
"K-factor." The K-factor is the ratio of the input speed of the
torque converter to the square root of the torque output of the
engine, as measured at any torque converter operating point. In
turn, the "operating point" of a torque converter is typically
defined by the ratio of the output speed to the input speed which
is also known as the speed ratio.
[0008] Torque converters occupy space in a powertrain assembly,
while space is at a premium. Transmissions with high gear content
leave less axial space for the torque converter. However, torque
converters having axially compact tori typically have been known to
carry an increased risk of cavitation, which increases the K-factor
and could present undesirable noise. All things being equal, it is
desirable to achieve a low K-factor across the entire speed ratio
range. Increased efficiency of energy transfer through a torque
converter is also a highly desirable goal. Accordingly, there is a
need for a torque converter that can fit into a small axial space,
but that can still meet the desired design goals for the K-Factor
and overall performance of the torque converter.
SUMMARY
[0009] The present disclosure provides a torque converter having an
axially compact torus and blades that provide an unexpectedly good
hydrodynamic performance, given the axial size of the torus. In
some embodiments, the torque converter has high K-factor extension
and coupling capacity to enable tight electronically controlled
capacity clutch (ECCC) slip speed control.
[0010] In one variation, a torque converter is provided that
includes an annular housing, a pump member, a turbine member, and a
stator member. The turbine member opposes the pump member. In one
variation, the torque converter has a torus width to torque
converter diameter ratio of about 0.15 to 0.17.
[0011] In some embodiments, the torque converter disclosed herein
has one or more of the following characteristics: an aspect ratio
(torus width divided by torus height) of about 0.73 to 0.78; a
passage height to torque converter diameter ratio of about 0.053 to
0.057; a torus position (2 times the stator shell radius divided by
the torque converter diameter) of about 0.55 to about 0.61; a torus
area ratio distribution of about 75% to 90% at partial length
fraction; a coupling speed ratio of about 0.89 to 0.90; a retention
(K.sub.cp/K.sub.s) of about 1.01 to 1.10; a stator torus having a
longer length at the shell than at the core; a ratio of the torus
length at the shell to the torus length at the core of about 1.2 to
1.9; twisted stator blades with lower blade angles at the shell
than at the core; stator blades having an inlet core angle minus
inlet shell angle of about 12 to 17 degrees; and stator blades
having an outlet core angle minus outlet shell angle of about 9 to
22 degrees.
[0012] In one variation, which may be combined with or separate
from the other variations described herein, a torque converter for
a motor vehicle is provided. The torque converter includes an
impeller member configured to be driven hydraulically by a prime
mover of the motor vehicle and a turbine member configured to
receive fluid energy from the impeller member and convert the fluid
energy to mechanical energy. The turbine member is disposed
opposite the impeller member. The impeller member and the turbine
member cooperate to define a torus width L.sub.t and a torque
converter diameter D. A stator member is disposed between the
impeller member and the turbine member. The stator member is
configured to increase torque multiplication of the torque
converter. The torque converter has a torus width L.sub.t to torque
converter diameter D ratio (L.sub.t/D) in the range of about 0.15
to about 0.17.
[0013] In another variation, which may be combined with or separate
from the other variations described herein, a torque converter for
a motor vehicle is provided. The torque converter includes an
impeller member configured to be driven hydraulically by a prime
mover of the motor vehicle and a turbine member configured to
receive fluid energy from the impeller member and convert the fluid
energy to mechanical energy. The turbine member is disposed
opposite the impeller member. A stator member is disposed between
the impeller member and the turbine member. The stator member is
configured to increase torque multiplication of the torque
converter. The stator member has a plurality of stator blades. Each
stator blade of the plurality of stator blades extends at an inlet
core stator blade angle .theta. from a center line C of torque
converter flow at a core side of the stator member and at an inlet
side of the stator member. Each stator blade extends at an outlet
core stator blade angle .gamma. from a center line C of torque
converter flow at the core side of the stator member and at an
outlet side of the stator member. Further, each stator blade
extends at an inlet shell stator blade angle .alpha. from a center
line C of torque converter flow at a shell side of the stator
member and at an inlet side of the stator member, and each stator
blade extends at an outlet shell stator blade angle .beta. from a
center line C of torque converter flow at the shell side of the
stator member and at the outlet side of the stator member. The
inlet shell stator blade angle .alpha. is less than the inlet core
stator blade angle .theta., and the outlet shell stator blade angle
.beta. is less than the outlet core stator blade angle .gamma..
[0014] Further features and aspects of the present invention will
become apparent by reference to the following description and
appended drawings wherein like reference numbers refer to the same
component, element or feature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The drawings described herein are for illustration purposes
only and are not intended to limit the scope of the present
disclosure in any way.
[0016] FIG. 1 is a schematic diagram of a torque converter
according to the principles of the present disclosure;
[0017] FIG. 2A is a graph of torus area ratio as a function of
torus length fraction of the torque converter of FIG. 1, in
accordance with the principles of the present disclosure;
[0018] FIG. 2B is a schematic cross-sectional view of a flow path
through the controlled area torus portion of the torque converter
of FIG. 1, according to the principles of the present
disclosure;
[0019] FIG. 3A is a plan view of a portion of a stator for use with
the torque converter of FIG. 1, in accordance with the principles
of the present disclosure;
[0020] FIG. 3B is a side view of the stator of FIG. 3A, according
to the principles of the present disclosure;
[0021] FIG. 3C is a schematic cross-sectional view of a blade of
the stator of FIGS. 3A-3B, taken along the line 3C-3C of FIG. 3A at
the core of the stator, in accordance with the principles of the
present disclosure;
[0022] FIG. 3D is a schematic cross-sectional view of a blade of
the stator of FIGS. 3A-3B, taken along the line 3D-3D of FIG. 3A at
the shell of the stator, according to the principles of the present
disclosure; and
[0023] FIG. 4 is a graph of torque ratio, K-factor, and efficiency
as a function of speed ratio of four variations of the torque
converter of FIG. 1, in accordance with the principles of the
present invention.
DESCRIPTION
[0024] Referring to the drawings, wherein like reference numbers
refer to like components, in FIG. 1 a schematic diagram view of a
torque converter 10 illustrated in accordance with an embodiment of
the present invention. The torque converter 10 is disposed in a
vehicle between a power source or prime mover 12 and a transmission
14. The prime mover 12 is, for example, an engine or motor and is
operable to provide torque to a rotatable engine output shaft 16.
It should be appreciated that other types of prime movers may be
used without departing from the scope of the present invention.
[0025] The transmission 14 generally includes at least one
rotatable transmission input shaft 18 that transfers torque to a
plurality of gear sets, a plurality of shafts, and a plurality of
torque transmitting mechanisms (not shown) to provide a plurality
of speed or gear ratios. It should be appreciated that the input
shaft 18 as illustrated may alternatively be considered an output
shaft of the torque converter 10 and may be a separate shaft
rotatably coupled to the transmission input shaft. The plurality of
shafts may include layshafts or countershafts, sleeve and center
shafts, reverse or idle shafts, or combinations thereof. It should
be appreciated that the specific arrangement and number of the gear
sets and the specific arrangement and number of the shafts within
the transmission 14 may vary without departing from the scope of
the present disclosure.
[0026] The torque converter 10 includes a pump or impeller 20 and a
turbine 22 disposed opposite the impeller 20. A stator 24 is
disposed between inner portions of the turbine 22 and impeller 20,
as schematically illustrated in FIG. 1. The impeller 20 is
generally annular in shape and includes a plurality of fins or
blades (not shown) oriented to transfer rotational energy from the
impeller 20 to a hydraulic fluid (not shown) disposed within an
annular housing (not shown) that surrounds that impeller 20,
turbine 22, and stator 24. The turbine 22 is generally annular in
shape and includes a plurality of fins or blades (not shown) that
oppose the impeller 20 and are oriented to transfer rotational
energy from the hydraulic fluid (not shown) to the turbine 22.
[0027] The stator 24 may be rotatably coupled through a one-way
clutch 26 to a stationary shaft 28. The stator 24 includes a
plurality of angled fins or blades (not shown in FIG. 1, see FIGS.
3A-3B) extending radially and circumferentially from a center of
the stator 24 to redirect hydraulic fluid that exits the turbine
22. The one-way clutch 26 allows rotation of the stator 24 in the
rotational direction of the impeller 20 and resists or prevents
rotation of the stator 24 in the rotational direction opposite the
rotational direction of the impeller 20. In the example provided,
the stationary shaft 28 is coupled to a stationary component in the
transmission.
[0028] The torque converter 10 has an axially compact torus design,
such that the ratio (L.sub.t/D) of torus width (L.sub.t) to torque
converter diameter D is about 0.15 to 0.17, and in some variations,
about 0.16 or 0.163. The following Table 1 provides additional
parameters that define an embodiment of the torque converter 10.
The variables used are graphically illustrated in FIG. 1. For
example, FIG. 1 schematically illustrates the torque converter
diameter D, the torus width L.sub.t, the passage height h, the
stator shell radius R.sub.s, the torus height d, the
two-dimensional length of the stator blade at the core Ls.sub.c
(described in further detail below) and the two-dimensional length
of the stator blade at the shell Ls.sub.s (described in further
detail below).
TABLE-US-00001 TABLE 1 Torque Converter 10 Design Ratios. Torus
Design Ratios Aspect Torus position Torus Area L.sub.t/D Ratio,
L.sub.t/d h/D 2 * R.sub.s/D Ratio Distribution 0.15 to 0.73 to
0.053 to 0.55 to 0.61 75% to 90% at partial 0.17 0.78 0.057 length
fraction
[0029] The values in Table 1 may be considered to be exact, in some
embodiments, or approximate, in other embodiments. Thus, the torque
converter 10 includes a torus width L.sub.t to torque converter
diameter D ration (L.sub.t/D) of about 0.15 to 0.17, an aspect
ratio (L.sub.t/d) of about 0.73 to 0.78, a passage height h to
torque converter diameter D ratio (h/D) of about 0.053 to 0.057, a
torus position (2*R.sub.s/D) of about 0.55 to 0.61, and a torus
area ratio distribution of about 75% to 90%.
[0030] In other variations, the shape and dimensions of the torque
converter 10, including the impeller 20, the turbine 22, and the
stator 24, may vary in length, width, and other dimensions based on
design considerations. For example, the torque converter 10 could
have a larger torque converter diameter D, while keeping the same
L.sub.t/D ratio of about 0.15 to 0.17, or at about 0.16 or
0.163.
[0031] The torque converter 10 may have a controlled torus flow
area ratio, as disclosed in U.S. Pat. No. 7,082,755, commonly
assigned to GM Global Technology Operations, Inc., and herein
incorporated by reference in its entirety. For example, referring
to FIGS. 2A-2B, the controlled torus area ratio is illustrated
graphically and schematically. One half of the torus 30 of the
torque converter 10 is illustrated. The inlet is indicated at
reference number 34 for the impeller 20 and 32 for the turbine 22.
As shown graphically in FIG. 2A, the gross torus flow area ratio
decreases from the turbine inlet 32 to a minimum point M between
about 0.6 and 0.8 torus length fraction, which is the distance
along the torus length TL. From the minimum point M, the gross
torus flow area ratio increases to the outlet 34 of the turbine 22.
Thus, the torus area ratio distribution decreases along the torus
length TL by an amount in the range of 75% to 90%, by way of
example, as indicated in Table 1. This change in gross flow area
ratio reduces or eliminates the energy losses which otherwise might
occur within the flow path. In this embodiment, both the turbine 22
and the impeller 20 have a torus structure wherein the inlet (which
is 32 for the turbine 22 and 34 for the impeller 20) of the passage
36 are larger in annular area than the middle annular area,
particular at the minimum point M.
[0032] Referring now to FIGS. 1, 3A-3D and Table 2, details of one
variation of the stator 24 are described. The stator 24 has a shell
38, a core 40, and a plurality of stator blades 42. The torque
converter 10 may have a higher number of blades than traditional
designs. For example, the impeller 20 may have 37 pump blades (not
illustrated), and the turbine 22 may have 35 turbine blades (not
illustrated). The stator 24 may have 20-42 stator blades 42,
depending on the desired K-factor. Each stator blade 42 has a first
end 44 affixed to the stator shell 38 and a second end 46 affixed
to the stator core 40.
[0033] Referring to FIG. 3C, a cross-sectional view of a stator
blade 42 taken along the line 3C-3C in FIG. 3A at the core 40 is
illustrated. The stator blade 42 extends at an angle .theta. from
the center line C of torque convertor flow at the core 40 at the
inlet side 48 of the stator 24. The stator blade 42 extends at an
angle .gamma. from the center line C of torque converter flow at
the core 40 at the outlet side 50 of the stator 24. Referring to
FIG. 3D, a cross-sectional view of one of the stator blades 42 of
FIG. 3C is taken along the line 3D-3D in FIG. 3A at the shell 38 of
the stator 24. The stator blade 42 extends at an angle .alpha. from
the center line C of torque converter flow at the shell 38 at the
inlet side 48 of the stator 24. The stator blade 42 extends at an
angle .beta. from the center line C of torque converter flow at the
shell 38 at the outlet side 50 of the stator 24. The blades 42 are
twisted such that they have lower shell blade angles .alpha.,
.beta. at the shell 38 than the core blade angles .theta., .gamma.
at the core 40, at both the inlet and outlet sides 48, 50 of the
stator 24. For example, the inlet core angle .theta. minus the
inlet shell angle .alpha. may be about 12-17 degrees; and for
example, the outlet core angle .gamma. minus the outlet shell angle
.beta. may be about 9-22 degrees.
[0034] The stator blades 42 may also have a longer two-dimensional
length at the shell than at the core. For example, the stator blade
length at the shell Ls.sub.s is greater than the stator blade
length at the core Ls.sub.c (see FIG. 1 for graphical
representation though because of the schematic nature of the stator
24 in FIG. 1, Ls.sub.s does not appear larger than Ls.sub.c). The
ratio of stator blade length at the shell Ls.sub.c to stator blade
length at the core Ls.sub.c may be about 1.2 to 1.9, by way of
example. The blade angle and stator length at the shell and core
parameters are also shown in Table 2.
TABLE-US-00002 TABLE 2 Launch Torus Torque Converter Stator Design
parameters. Description Parameter Range Longer two-dimensional
Ls.sub.s/Ls.sub.c 1.2 to 1.9 stator blade length at shell Ls.sub.s
than core Ls.sub.c Twisted blades 42 with Inlet core blade angle
.theta. 12 to 17 degrees lower shell blade angles minus inlet shell
blade .alpha. than core blade angles angle .alpha. .theta. at inlet
48 Twisted blades 42 with Outlet core blade angle .gamma. 9 to 22
degrees lower shell blade angles minus outlet shell blade .beta.
than core blade angles angle .beta. .gamma. at outlet 50
[0035] Referring now to FIG. 4 and Table 3, the torque converter
performance is illustrated with four different K-factor designs of
the torque converter 10A, 10B, 10C, 10D. The torque ratio as a
function of speed ratio is illustrated at set 52 of the torque
converter data 10A, 10B, 10C, 10D. The K-factor as a function of
speed ratio is illustrated at set 54 of the torque converter data
10A, 10B, 10C, 10D. The efficiency as a function of speed ratio is
illustrated at set 56 of the torque converter data 10A, 10B, 100,
10D. For torque converters 10A-10D, the torque converters 10A-10D
had a coupling speed ratio of about 0.89 to 0.90 and a retention
(K.sub.cp/K.sub.s) of about 1.01 to 1.10, where K.sub.cp is the
K-factor at the coupling speed ratio and K.sub.s is the K-factor at
the stall speed ratio. Table 3 also shows these parameters.
TABLE-US-00003 TABLE 3 Coupling Speed Ratio Capacity. Coupling
Speed Ratio Retention (K.sub.cp/K.sub.s) 0.89 to 0.90 1.01 to
1.10
[0036] The description of the invention is merely exemplary in
nature and variations that do not depart from the general essence
of the invention are intended to be within the scope of the
invention. Such variations are not to be regarded as a departure
from the spirit and scope of the invention.
* * * * *