U.S. patent application number 14/482804 was filed with the patent office on 2015-03-12 for torque converter impeller including impeller shell having thinned section.
The applicant listed for this patent is Schaeffler Technologies GmbH & Co. KG. Invention is credited to David Burky, JR., Michael Resh.
Application Number | 20150071789 14/482804 |
Document ID | / |
Family ID | 52478790 |
Filed Date | 2015-03-12 |
United States Patent
Application |
20150071789 |
Kind Code |
A1 |
Resh; Michael ; et
al. |
March 12, 2015 |
TORQUE CONVERTER IMPELLER INCLUDING IMPELLER SHELL HAVING THINNED
SECTION
Abstract
An impeller for a torque converter is provided. The impeller
includes an impeller shell including an inner circumference, an
outer circumference and a radial extension extending radially
outward from the inner circumference. The radial extension includes
an axially extending groove formed therein. The impeller also
includes an impeller hub welded to the impeller shell by a weld.
The weld is radially inside of the axially extending groove. The
axially extending groove is 5 to 10 millimeters from the weld. A
method of forming an impeller for a torque converter is also
provided.
Inventors: |
Resh; Michael; (Massillon,
OH) ; Burky, JR.; David; (Massillon, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Schaeffler Technologies GmbH & Co. KG |
Herzogenaurach |
|
DE |
|
|
Family ID: |
52478790 |
Appl. No.: |
14/482804 |
Filed: |
September 10, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61876843 |
Sep 12, 2013 |
|
|
|
Current U.S.
Class: |
416/234 ;
29/889.5 |
Current CPC
Class: |
Y10T 29/4933 20150115;
F16H 45/02 20130101; F16H 2045/0205 20130101; F04D 29/18 20130101;
F16H 2045/0226 20130101; F16H 2045/0278 20130101 |
Class at
Publication: |
416/234 ;
29/889.5 |
International
Class: |
F04D 29/18 20060101
F04D029/18 |
Claims
1. An impeller for a torque converter comprising: an impeller shell
including an inner circumference, an outer circumference and a
radial extension extending radially outward from the inner
circumference, the radial extension including an axially extending
groove formed therein; and an impeller hub welded to the impeller
shell by a weld, the weld being radially inside of the axially
extending groove, the axially extending groove being 5 to 10
millimeters from the weld.
2. The impeller as recited in claim 1 wherein the radial extension
includes a flat inner radial portion, the weld being formed on the
flat inner radial portion, the radial extension protruding slightly
axially inward to form an intermediate portion radially outside of
the flat inner radial portion, the axially extending groove being
formed in the intermediate portion.
3. The impeller as recited in claim 1 wherein the axially extending
groove has a curved surface, the curved surface having a radius of
curvature of at least 5 millimeters.
4. The impeller as recited in claim 1 wherein the axially extending
groove is formed as a ring shaped groove extending
circumferentially around the inner circumference.
5. The impeller as recited in claim 1 wherein the axially extending
groove is formed in a back surface of the impeller shell, the
impeller shell including a machined portion on a front surface of
the radial extension opposite the axially extending groove.
6. The impeller as recited in claim 5 wherein the radial extension
includes a flat inner radial portion, the weld being formed on the
flat inner radial portion, the radial extension protruding slightly
axially inward to form an intermediate portion radially outside of
the flat inner radial portion, the axially extending groove and the
machined portion being formed in the intermediate portion.
7. The impeller as recited in claim 5 wherein the machined portion
is thinner than a remainder of the radial extension.
8. The impeller as recited in claim 6 wherein the machined portion
is formed as a ring shaped flat surface.
9. The impeller as recited in claim I further comprising impeller
blades, the impeller shell including a rounded portion radially
outside of the radial extension, the rounded portion supported the
impeller blades.
10. The impeller as recited in claim 9 wherein the impeller shell
includes an axial extension radially outside of the rounded portion
for connected to a torque converter front cover, the axial
extension defining the outer circumference.
11. A torque converter comprising the impeller as recited in claim
1.
12. A method of forming an impeller for a torque converter
comprising: providing an impeller shell including an inner
circumference, an outer circumference and a radial extension
extending radially outward from the inner circumference; forming an
axially extending groove in the radial extension; and welding an
impeller hub to the impeller shell so as to form a weld on a back
surface of the radial extension, the weld being radially inside of
the axially extending groove, the axially extending groove being 5
to 10 millimeters from the weld.
13. The method as recited in claim 12 wherein the radial extension
includes a flat inner radial portion, the weld being formed on the
flat inner radial portion, the radial extension protruding slightly
axially inward to form an intermediate portion radially outside of
the flat inner radial portion, the axially extending groove being
formed in the intermediate portion.
14. The method as recited in claim 12 wherein the forming the
axially extending groove includes machining the axially extending
groove into the radial extension.
15. The method as recited in claim 12 wherein the forming the
axially extending groove includes stamping the axially extending
groove into the radial extension.
16. The method as recited in claim 12 wherein the axially extending
groove is formed in a back surface of the impeller shell, the
method further including machining a front surface of the radial
extension opposite the axially extending groove.
17. The method as recited in claim 16 wherein the radial extension
includes a flat inner radial portion, the weld being formed on the
flat inner radial portion, the radial extension protruding slightly
axially inward to form an intermediate portion radially outside of
the flat inner radial portion, the axially extending groove being
formed in a back surface of the intermediate portion, the machining
including machining a front surface of the intermediate
portion.
18. The method as recited in claim 16 wherein after the forming the
axially extending groove and machining the front surface, the
radial extension has a thickness of at least 1.7 millimeters at the
axially extending groove.
19. The method as recited in claim 12 wherein the axially extending
groove has a curved surface, the curved surface having a radius of
curvature of at least 5 millimeters.
20. The method as recited in claim 12 wherein the axially extending
groove is formed as a ring shaped groove extending
circumferentially around the inner circumference.
Description
[0001] This claims the benefit to U.S. Provisional Patent
Application No. 61/876,843, filed on Sep. 12, 2013, which is hereby
incorporated by reference herein.
[0002] The present disclosure relates generally to torque
converters and more specifically to impellers of torque
converters.
BACKGROUND OF INVENTION
[0003] U.S. Pub. 2012/0151907 discloses method of connecting an
impeller hub and impeller shell.
BRIEF SUMMARY OF THE INVENTION
[0004] An impeller for a torque converter is provided. The impeller
includes an impeller shell including an inner circumference, an
outer circumference and a radial extension extending radially
outward from the inner circumference. The radial extension includes
an axially extending groove formed therein. The impeller also
includes an impeller hub welded to the impeller shell by a weld.
The weld is radially inside of the axially extending groove. The
axially extending groove is 5 to 10 millimeters from the weld.
[0005] A method of forming an impeller for a torque converter is
provided. The method includes providing an impeller shell including
an inner circumference, an outer circumference and a radial
extension extending radially outward from the inner circumference;
forming an axially extending groove in the radial extension; and
welding an impeller hub to the impeller shell so as to form a weld
on a back surface of the radial extension. The weld is radially
inside of the axially extending groove and the axially extending
groove is 5 to 10 millimeters from the weld.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The present invention is described below by reference to the
following drawings, in which:
[0007] FIG. 1 shows a schematic cross-sectional side view of a
torque converter including an impeller in accordance with an
embodiment of the present invention;
[0008] FIG. 2a shows a cross-sectional side view of an impeller
shell of the impeller;
[0009] FIG. 2b shows an enlarged view of a radial extension of the
impeller shell as shown in the cross-sectional side view shown in
FIG. 2a;
[0010] FIG. 2c shows a perspective view of a back surface of the
impeller;
[0011] FIG. 3a shows a cross-sectional side view of the impeller
after a front surface of impeller shell has been thinned; and
[0012] FIG. 3b shows an enlarged view of the radial extension of
the impeller shell as shown in the cross-sectional side view shown
in FIG. 3a.
DETAILED DESCRIPTION
[0013] One embodiment of the present invention includes an impeller
shell having a particular radius formed therein that is then
machined to create a flexible thinned section. Testing has shown
that adding flexibility to the impeller shell may improve
durability of the impeller hub weld. The impeller shell is thinned
by machining the back side of the radius to form a bearing
surface.
[0014] FIG. 1 shows a schematic cross-sectional side view of a
torque converter 10 including an impeller 12 in accordance with an
embodiment of the present invention. Torque converter 10 includes a
cover 14 including a front cover 16 and a rear cover 18, which is
formed by an impeller shell 20 of impeller 12. Cover 14 houses a
lockup clutch 22 and a damper 24, which are both schematically
shown, and a turbine 26 opposite of impeller 12. Lockup clutch 22
engages with and disengages from front cover 16 and damper 24
couples turbine 26 to lockup clutch 22 such that turbine 26 is
circumferentially driven with front cover 16 when lockup clutch 22
is engaged with front cover 16. Impeller 20 further includes an
impeller hub 27 fixed to impeller shell 20 and impeller blades 36
supported by a rounded portion 34 of impeller shell 20.
[0015] FIG. 2a shows a cross-sectional side view of impeller shell
20. Impeller shell 20 includes an inner circumference 28, an outer
circumference 30 and a radial extension 32 extending radially from
inner circumference 28. Impeller shell 20 includes a rounded
portion 34 radially outside of radial extension 32. Rounded portion
34 is configured for supporting impeller blades 36 (FIGS. 1 and 3a)
and includes a plurality of slots 38 formed therein for receiving
blade tabs of impeller blades 36. Impeller shell 20 includes an
axial extension 40 radially outside of rounded portion 34 for
connecting to front cover 16 (FIG. 1). An outer radial surface of
axial extension 40 defines outer circumference 30.
[0016] FIG. 2b shows an enlarged view of radial extension 32 as
shown in the cross-sectional side view shown in FIG. 2a. Radial
extension 32 has an axially extending groove 42 formed in a back
surface 43 of impeller shell 20 for adding flexibility to impeller
shell 20. Axially extending groove 42 also extends
circumferentially. In this preferred embodiment, axially extending
groove 42 is formed during the stamping of impeller shell 20. In
other embodiments, axially extending groove 42 may be machined or
stamping into impeller shell 20 after impeller shell 20 has been
formed by stamping. Radial extension 32 is substantially plate
shaped and includes a flat inner radial portion 44 for connecting
to an impeller hub 46 (FIG. 3a). An inner radial surface of flat
inner radial portion 44 defines inner circumference 28. Radially
outward from flat inner radial portion 44, radial extension 32
protrudes slightly axially inward to form an intermediate portion
46. Intermediate portion 46 is substantially flat, except for
axially extending groove 42 and an axial protrusion 48 on a front
surface 50 of impeller shell 20 formed by material displaced during
the stamping of axially extending groove 42. Axially extending
groove 42 has a curved surface, which in this preferred embodiment
has a radius of curvature R of at least 5 millimeters. Axially
extending groove 42 has a depth D of approximately 0.8
millimeters.
[0017] FIG. 2c shows a perspective view of the back surface 43 of
impeller 12. As shown in FIG. 2c, axially extending groove 42 is
ring shaped and extends continuously circumferentially around back
surface 43.
[0018] FIG. 3a shows a cross-sectional side view of impeller 12
after front surface 50 of impeller shell 20 has been thinned and
FIG. 3b shows an enlarged view of radial extension 32 as shown in
the cross-sectional side view shown in FIG. 3a. Specifically, front
surface 50 has been machined at intermediate portion 46 to remove
material from impeller shell 20 opposite of axially extending
groove 42. As shown in FIG. 3b, after machining, intermediate
portion 46 still protrudes slightly with respect to flat inner
radial portion 44. In this preferred embodiment, the thickness X of
impeller 20 at axially extending groove 42 is at least 1.7
millimeters after the thinning of front surface 50 of radial
extension 32. After the machining, axial protrusion 48 has been
removed and a machined portion 52 that is ring shaped and has a
flat surface is formed. The machining adds further flexibility to
impeller shell 20. As shown in FIG. 3a, rounded portion 34 supports
a plurality of impeller blades 36.
[0019] Impeller hub 27 is welded to impeller shell 20 by a weld 54
extending circumferentially around impeller hub 27 at a front end
56 thereof. Front end 56 rests against back surface 43 of impeller
shell 20. To add desired flexibility to impeller shell 20, axially
extending groove 42 is spaced from weld 54 by a radial distance Y
that is between 5 to 10 millimeters. Testing has shown that this
adding of flexibility to the impeller shell 20 improves durability
of impeller hub weld 54.
[0020] 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.
* * * * *