U.S. patent application number 15/140757 was filed with the patent office on 2017-11-02 for torque converter including spacer plate for coast engagement diaphragm spring.
The applicant listed for this patent is Schaeffler Technologies AG & Co. KG. Invention is credited to Sagar ADARI, David AVINS, Kyle NELSON.
Application Number | 20170314662 15/140757 |
Document ID | / |
Family ID | 60158185 |
Filed Date | 2017-11-02 |
United States Patent
Application |
20170314662 |
Kind Code |
A1 |
NELSON; Kyle ; et
al. |
November 2, 2017 |
TORQUE CONVERTER INCLUDING SPACER PLATE FOR COAST ENGAGEMENT
DIAPHRAGM SPRING
Abstract
A torque converter is provided. The torque converter includes a
damper assembly and a turbine assembly connected to the damper
assembly. The turbine assembly includes an axially movable turbine
piston, a spacer plate fixed to the turbine piston and a bias
spring. The spacer plate retains the bias spring on the turbine
piston with a preload force. A method of forming a torque converter
is also provided. The method includes providing a bias spring
contacting a front cover side surface of a turbine piston; and
fixing a spacer plate to the turbine piston such that the spacer
plate holds the bias spring against the front cover side surface of
the turbine piston.
Inventors: |
NELSON; Kyle; (Dover,
OH) ; AVINS; David; (Burbank, OH) ; ADARI;
Sagar; (Wooster, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Schaeffler Technologies AG & Co. KG |
Herzogenaurach |
|
DE |
|
|
Family ID: |
60158185 |
Appl. No.: |
15/140757 |
Filed: |
April 28, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16H 2045/0205 20130101;
F16H 2045/0263 20130101; F16H 2045/0247 20130101; F16H 41/28
20130101; F16H 45/02 20130101 |
International
Class: |
F16H 45/02 20060101
F16H045/02; F16H 41/28 20060101 F16H041/28 |
Claims
1. A torque converter comprising: a damper assembly; and a turbine
assembly connected to the damper assembly, the turbine assembly
comprising: an axially movable turbine piston; a spacer plate fixed
to the turbine piston; and a bias spring, the spacer plate
retaining the bias spring on the turbine piston with a preload
force.
2. The torque converter as recited in claim 1 wherein the damper
assembly includes a drive flange configured for connecting to a
transmission input shaft, the drive flange including surfaces
contacting the bias spring that are configured such that when the
damper assembly travels into a coast direction an axial force is
exerted on the turbine piston by the bias spring.
3. The torque converter as recited in claim 2 wherein the bias
spring includes outer tabs configured for contacting the surfaces
of the drive flange.
4. The torque converter as recited in claim 3 wherein the spacer
plate includes an outer base section fixed onto the turbine piston
and fingers protruding axially and radially from the base section,
the fingers extending through spaces formed between the outer
tabs.
5. The torque converter as recited in claim 4 wherein at least one
of the fingers includes a contact edge configured for contacting a
side surface of a respective one of the outer tabs to transmit
torque from the turbine piston to the bias spring through the
spacer plate to generate the axial force.
6. The torque converter as recited in claim 4 wherein the bias
spring is a diaphragm spring including a base ring, the outer tabs
being formed at an outer diameter of the base ring, the fingers
contacting a front cover side surface of the base ring to hold the
diaphragm spring against the turbine piston.
7. The torque converter as recited in claim 4 wherein the spacer
plate includes an inner base section contacting a turbine side
surface of the drive flange, the fingers extending from the outer
base section to the inner base section.
8. The torque converter as recited in claim 3 wherein at least one
of the surfaces of the drive flange and surfaces of the outer tabs
are axially tapered to form ramps.
9. The torque converter as recited in claim 1 further comprising an
impeller shell, the turbine piston including an outer radial
extension configured for frictionally engaging with and disengaging
from the impeller shell to form a lockup clutch.
10. The torque converter as recited in claim 1 wherein the turbine
piston includes an annular inner radial extension, the bias spring
including inner tabs contacting the annular inner radial
extension.
11. The torque converter as recited in claim 1 wherein the turbine
assembly includes a blade supporting portion and drive tabs fixed
to the blade supporting portion, the damper assembly including a
plurality of circumferentially spaced springs, the drive tabs
circumferentially engaging the springs to connect the turbine
assembly to the damper assembly.
12. A method of forming a torque converter comprising: providing a
bias spring contacting a front cover side surface of a turbine
piston; and fixing a spacer plate to the turbine piston such that
the spacer plate holds the bias spring against the front cover side
surface of the turbine piston.
13. The method as recited in claim 12 further comprising connecting
the turbine piston to a damper assembly including a drive flange
with surfaces of the drive flange contacting the bias spring such
that when the damper assembly travels into a coast direction
contact between the surfaces of the drive flange and the bias
spring result in an axial force being exerted on the turbine piston
by the bias spring.
14. The method as recited in claim 13 further comprising fixing
drive tabs to a blade supporting portion of the turbine piston, the
damper assembly including a plurality of circumferentially spaced
springs, the drive tabs circumferentially engaging the springs to
connect the turbine piston to the damper assembly.
15. The method as recited in claim 12 wherein the spacer plate
includes an outer base section fixed in contact with the turbine
piston and fingers protruding axially and radially from the base
section, the fingers extending through spaces formed between outer
tabs of the bias spring.
16. The method as recited in claim 15 wherein at least one of the
fingers includes a contact edge configured for contacting a side
surface of a respective one of the outer tabs to transmit torque
from the turbine piston to the bias spring through the spacer plate
to generate the axial force.
17. The method as recited in claim 15 wherein the bias spring is a
diaphragm spring including a base ring, the outer tabs being formed
at an outer diameter of the base ring, the fingers contacting a
front cover side surface of the base ring to hold the diaphragm
spring against the turbine piston.
Description
[0001] The present disclosure relates generally to torque
converters and more specifically to torque converters including a
turbine piston.
BACKGROUND
[0002] U.S. Pat. No. 9,080,616 discloses transmission subassembly
that includes a contained return spring. U.S. Publication No.
2014/0097055 discloses a torque converter with a turbine piston,
which is an axially movable turbine used as a piston of a lockup
clutch.
SUMMARY OF THE INVENTION
[0003] A torque converter is provided. The torque converter
includes a damper assembly and a turbine assembly connected to the
damper assembly. The turbine assembly includes an axially movable
turbine piston, a spacer plate fixed to the turbine piston and a
bias spring. The spacer plate retains the bias spring on the
turbine piston with a preload force.
[0004] A method of forming a torque converter is also provided. The
method includes providing a bias spring contacting a front cover
side surface of a turbine piston; and fixing a spacer plate to the
turbine piston such that the spacer plate holds the bias spring
against the front cover side surface of the turbine piston.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The present invention is described below by reference to the
following drawings, in which:
[0006] FIG. 1a shows cross-sectional side views of a torque
converter in accordance with an embodiment of the present
invention;
[0007] FIG. 1b shows a view along A-A of FIG. 1a;
[0008] FIG. 2 shows a cross-sectional side view of a radially inner
portion of turbine assembly of the torque converter shown in FIG.
1a;
[0009] FIG. 3 shows a side view of the entirety of the turbine
assembly shown in FIG. 2;
[0010] FIG. 4 shows a plan view of a front cover facing side of the
turbine assembly shown in FIGS. 2 and 3; and
[0011] FIG. 5 shows a perspective view of the front cover facing
side of the turbine assembly shown in FIGS. 3 to 5.
DETAILED DESCRIPTION
[0012] The disclosure provides a spacer plate to capture a
diaphragm spring, thus eliminating the need for an additional outer
diameter tab formed on the diaphragm spring to maintain preload and
transmit torque. The spacer plate includes function of two tabs in
one by transmitting torque directly through the ramp tab to the
spacer plate. The spring preload is held on the outer diameter of
the spring body. Torque is advantageously transferred locally at
the outer diameter tab and bending moment is practically
eliminated, thus extending fatigue life.
[0013] FIG. 1 shows cross-sectional side views of a torque
converter 10 in accordance with an embodiment of the present
invention. Torque converter 10 is rotatable about a center axis 11
and includes a front cover 12 for connecting to a crankshaft of an
internal combustion engine and a rear cover 14 forming a shell 16
of an impeller or pump 18. The terms axially, radially and
circumferentially as used herein are used with respect to center
axis 11. Torque converter 10 also includes a turbine assembly 19 in
accordance with an embodiment of the present invention. Turbine
assembly 19 includes a turbine 20 configured to define a piston
that is axially moveable toward and away from impeller 18 to engage
and disengage an impeller clutch of impeller 18 so as to form a
lockup clutch. Turbine piston 20 includes a turbine shell 22 and a
core ring 24 supporting a plurality of turbine blades 26
therebetween.
[0014] Turbine shell 22 includes a rounded blade supporting portion
28, which is shaped as an annular bowl, for contacting engine side
edges of turbine blades 26. Radially outside of blade supporting
portion 28, an outer radial extension 30, which forms the piston,
radially protrudes outwardly from an outer circumference of blade
supporting portion 28 to define an annular protrusion having a flat
annular radially extending impeller facing surface 30a and having
an outermost circumference that defines an outermost circumference
of turbine piston 20. Accordingly, the piston and turbine shell 22
are formed as a single piece. Radially inside of blade supporting
portion 28, turbine shell 22 includes an annular inner radial
extension 31 that, at an inner radial end thereof, joins an axially
extending inner circumferential section 33, whose inner
circumferential surface contacts an outer circumferential surface
of a hub 35.
[0015] Impeller 18 includes impeller blades 34, which are each
fixed at a transmission side thereof to impeller shell 16 and are
each fixed to an impeller core ring 37 at an engine side thereof by
tabs. Impeller shell 16 includes a rounded blade supporting portion
32, which is shaped as an annular bowl, for contacting transmission
side edges of impeller blades 34. Radially outside of blade
supporting portion 32, a radially extending wall 36, which forms an
impeller clutch, radially protrudes outwardly from an outer
circumference of rounded blade supporting portion 32 to define an
annular wall having a flat annular radially extending turbine
facing surface 36a. Accordingly, the impeller clutch and impeller
shell 16 are formed as a single piece. Radially inside of blade
supporting portion 32, impeller shell 16 includes an annular inner
radial extension 39 extending radially inward from blade supporting
portion 32. A radially inner end of extension 39 is connected to an
impeller hub 41.
[0016] A friction material 40 is bonded onto radially extending
impeller facing surface 30a of outer radial extension 30 for
engaging radially extending wall 36. In other embodiments, instead
of or in addition to being bonded to outer radial extension 30,
friction material 40 may be bonded to radially extending turbine
facing surface 36a of radially extending wall 36. Regardless of
whether friction material 40 is bonded to outer radial extension 30
or radially extending wall 36, friction material 40 is provided
axially between surfaces 30a, 36a.
[0017] Torque converter 10 also includes a stator 42 axially
between turbine 20 and impeller 18 to redirect fluid flowing from
the turbine blades 26 before the fluid reaches impeller 18 to
increase the efficiency of torque converter 10. Stator 42 includes
stator casting 44 including a plurality of blades 46 and a stator
body 48. Stator 42 also includes a one-way clutch 50 held within
stator body 48 by a centering plate 52. An axial thrust washer 54,
which is axially between stator 42 and impeller 18, is fixed to
stator 42 at an outer circumference of centering plate 52. One-way
clutch 50 includes an inner race 56, an outer race 58 and rollers
and springs 60 radially between inner race 56 and outer race 58.
Stator casting 44 is rotationally fixed to outer race 58, and
depending on the operating conditions of torque converter 10, inner
race 56 and outer race 58 are rotationally fixed to each other or
rotatable relative to each other.
[0018] A damper assembly 62 is positioned between front cover 12
and turbine 20 and is configured for transferring torque from
turbine 20 to a transmission input shaft. In this embodiment,
damper assembly 62 is connected to the turbine piston 20 for
rotation therewith by drive tabs 64 circumferentially engaging a
radially outer set of springs 66 of damper assembly 62. Drive tabs
64 as formed as part of a drive ring 68 of turbine assembly 19.
Drive ring 68 is fixed to a front cover facing surface of turbine
shell 22 at blade supporting portion 28. An annular base 70 of
drive ring 68 is fixed in contact with front cover facing surface
of turbine shell 22 by welding or brazing. Drive tabs 64 are
circumferentially spaced from each other and extend into spaces
formed circumferentially between springs 66 to contact
circumferential edges of springs 66. Springs 66 are retained by a
spring retainer 72 that wraps around a contour of the outer
diameter of springs 66 and is formed at a radially outer end of a
first or turbine side cover plate 74 of damper assembly 62. Damper
assembly 62 further includes a second or front cover side cover
plates 76.
[0019] Cover plates 74, 76 support a set of radially inner springs
78, which are radially inside of springs 66, axially therebetween.
Damper assembly 62 also includes a drive flange 80 positioned
axially between cover plate 74, 76 including a hub 82 at a radially
inner end thereof configured for nonrotatably connecting to a
transmission input shaft. Radially outside of springs 78, cover
plates 74, 76 are fixed together by a plurality of
circumferentially spaced rivets 84. Drive flange 80 includes
circumferentially extending slots for receiving springs 66 formed
therein and a centrifugal pendulum absorber 86 at a radially outer
end thereof. Radially inside of springs 66, drive flange 80 is
provided with a plurality of surfaces 88 formed as ramps that each
taper axially from a first edge 88a that is axially furthest from
turbine 20 to a second edge 88b that is axially closest to turbine
20. First edge 88a is the flange surface that runs all the way from
the inner diameter of flange 80 to the outer diameter of flange 80
and second edge 88b is the top of the flange ramps. A thrust washer
89 is provided at a front cover side of second cover plate 76 to
contact an inner surface of front cover 12 to prevent cover plate
76 from frictionally engaging front cover 12 during rotation
thereof about axis 11.
[0020] Turbine assembly 19 also includes a turbine-side bias spring
90, which in this embodiment is a diaphragm spring, provided
axially between flange 70 and inner radial extension 31 of turbine
20. At an inner diameter of a base ring 91 thereof, bias spring 90
includes a plurality of radially and axially extending tabs 92 for
contacting front cover side surface 31a of inner radial extension
31. At an outer diameter of base ring 91, bias spring 90 includes a
plurality of axially extending drive flange engaging tabs 94, each
provided with a ramp contacting surface 96 at a side thereof formed
as ramps that each taper from an axial free end 96a thereof for
contacting a respective one of ramps 88 of drive flange 70. The
arrangement of tabs 94 with respect to ramps 88 is shown by FIG.
1b, which illustrates a view of one of tabs 94 and one of ramps 88
along A-A of FIG. 1a. As shown in FIG. 1b, ramps 96 taper in a
manner that match the respective ramps 88 and travel up and onto
edges 88b. An axial clearance is provided first edge 88a and axial
free end 96a. Each ramp 88 contacts one of surfaces 96 such that
relative circumferential motion between drive flange 70 and bias
spring 90 causes contact between the ramps 88 and surfaces 96 to
generate a force on turbine piston 20. When damper assembly 62
travels into the coast direction, ramps 88 contact surfaces 96 to
produce an axial force that is transmitted by bias spring 90 to
turbine piston 20. In alternative embodiment, surfaces 96 may be
formed as ramps that taper in a manner that match the respective
ramps 88. In other embodiments, surfaces 96 may be formed as ramps
instead of surfaces 88.
[0021] Turbine assembly 19 further includes a spacer plate 98
capturing diaphragm spring 90. Spacer plate 98 is fixed to inner
radial extension 31 of turbine 20 by a plurality of
circumferentially spaced rivets 100. Spacer plate 98 includes an
outer annular base section 102 contacting front cover side surface
31a of inner radial extension 31 and receiving rivets 100. Outer
base section 102 forms an outer diameter of spacer 98. A plurality
of circumferentially spaced fingers 104 protrude axially away from
and radially inward from base section 102 and extend axially
through spaces circumferentially between diaphragm engaging tabs 94
to join an annular inner base section 106, which form an inner
diameter of spacer 98. Fingers 104, via a turbine side surface 104a
thereof, contact a front cover side surface 90a of diaphragm spring
90 to prevent diaphragm spring 90 from moving axially away from
turbine 20. A front cover side surface 106a of inner base section
106 contacts a turbine side surface 70a of drive flange 70.
[0022] A method of forming torque converter 10 may include
providing bias spring 90 in contact with front cover side surface
31a of inner radial extension 31 of turbine piston 20 and then
fixing spacer plate 98, via rivets 100, to turbine piston 20 such
that spacer plate 98 holds bias spring 90 against front cover side
surface 31a of inner radial extension 31 of turbine piston 20.
[0023] FIGS. 2 to 5 illustrate various views of turbine assembly
19. FIG. 2 shows a cross-sectional side view of a radially inner
portion of turbine assembly 19, providing an enlarged view of
diaphragm spring 90 and spacer plate 98. FIG. 3 shows a side view
of the entirety of turbine assembly 19. FIG. 4 shows a plan view of
a front cover facing side of turbine assembly 19. FIG. 5 shows a
perspective view of the front cover facing side of turbine assembly
19.
[0024] FIG. 2 illustrates spacer plate 98 being fixed to inner
radial extension 31 of turbine shell 22 by rivets 100. Fingers 104
extend from outer base section 98 in between tabs 94 to inner base
section 106 and contact a front cover side surface 91a of base ring
91 of diaphragm spring 90 via turbine side surfaces 104a of fingers
104 to maintain a preload force F1 and transmit coast torque from
piston turbine 20 to diaphragm spring 90. Inner tabs 92 contact
front cover side surface 31a of inner radial extension 31 and outer
tabs 94 are configured for contacting ramps 88 of drive flange 70
(FIGS. 1a, 1b) to generate a ramp load force F2. Tabs 92 extend
from the inner diameter of base ring 91 of diaphragm spring 90 and
tabs 94 extend from the outer diameter of base ring 91. FIG. 2
further illustrates turbine blades 26 and the attachment of turbine
blades 26 to core ring 24.
[0025] FIG. 3 illustrates the positioning of spacer plate 98 and
diaphragm spring 90 on turbine shell 22. Outer tabs 94 are shown
extending radially through spaces formed between fingers 104 and
outside past fingers 104. Drive ring 68 is shown fixed to a front
cover facing surface of turbine shell 22 at blade supporting
portion 28, with annular base 70 being is fixed in contact with the
front cover facing surface of turbine shell 22 and drive tabs 62
protruding radially outward and axially away from annular base 70.
FIG. 3 further illustrates friction material 40 formed as a ring on
outer radial extension 30 of turbine shell 22.
[0026] FIGS. 4 and 5 illustrate the shape of outer base section 102
of spacer plate 98. Outer base section include an outer ring 110
forming an outer circumferential surface of spacer plate 98 and
rivet receiving protrusions 112 extending radially inward from
outer ring 110 for receiving rivets 100. As viewed axially, as
shown in FIG. 4, inner surfaces of protrusions 112 are defined by
arc-shaped cutouts 114 formed in spacer plate 98. Arc-shaped
cutouts 114 also each define one edge 104b of two different fingers
104. Further cutouts 116, which are rectangular in shape with
curved corners as viewed axially, are provided between cutouts 114,
such that cutouts 114 alternate with cutouts 116 in the
circumferential direction. Cutouts 116 also each define one contact
edge 104c of one of fingers 104, such that every other finger 104
includes one contact edge 104c. In standard operation, a torque
transmitting side surface 94a of each of tabs 94 of bias spring 90
contacts and transmits torque through a respective one of contact
edges 104c. Accordingly, tabs 94 transmit torque from turbine 20
through spacer plate 98 via contact edges 104c to generate the
axial force via ramps 96 Cutouts 114, 116 are all formed radially
between outer base section 102 and inner base section 106. Each of
outer tabs 94 extends radially and axially through a respective one
of cutouts 114. Inner tabs 92 extend radially inside of the inner
diameter of inner base section 106. Rounded blade supporting
portion 28 is positioned radially outside of space plate 98 and
supports drive ring 68, which includes annular base 70 and a
plurality of circumferentially spaced drive tabs 64. Outer radial
extension 30 of turbine shell 22 extends radially outside past
drive ring 68.
[0027] In the preceding specification, the invention has been
described with reference to specific exemplary embodiments and
examples thereof. It will, however, be evident that various
modifications and changes may be made thereto without departing
from the broader spirit and scope of invention as set forth in the
claims that follow. The specification and drawings are accordingly
to be regarded in an illustrative manner rather than a restrictive
sense.
* * * * *