U.S. patent application number 14/943466 was filed with the patent office on 2017-03-16 for planetary gear train of automatic transmission for vehicle.
This patent application is currently assigned to Hyundai Motor Company. The applicant listed for this patent is Hyundai Motor Company. Invention is credited to Wonmin CHO, Dong Hwan HWANG, Seong Wook HWANG, Seongwook JI, Jong Soo KIM, Hyun Sik KWON, Chang Wook LEE, KyeongHun LEE., JongSool PARK.
Application Number | 20170074363 14/943466 |
Document ID | / |
Family ID | 58236789 |
Filed Date | 2017-03-16 |
United States Patent
Application |
20170074363 |
Kind Code |
A1 |
PARK; JongSool ; et
al. |
March 16, 2017 |
PLANETARY GEAR TRAIN OF AUTOMATIC TRANSMISSION FOR VEHICLE
Abstract
A planetary gear train of an automatic transmission for a
vehicle may include an input shaft; an output shaft; a first to
fourth planetary gear sets; and six friction elements disposed
between at least one rotation element among the twelve rotation
elements and another rotation element or a transmission housing,
wherein the input shaft is continuously connected to the second
rotation element, the output shaft is continuously connected to the
eleventh rotation element, the first rotation element is
continuously connected to the fourth rotation element, the fifth
rotation element is continuously connected to the eighth rotation
element, the sixth rotation element is continuously connected to
the eleventh rotation element, the ninth rotation element is
continuously connected to the tenth rotation element, the second
rotation element is selectively connected to the third rotation
element, three friction elements among the six friction elements
are operated at each speed stage.
Inventors: |
PARK; JongSool;
(Hwaseong-si, KR) ; HWANG; Dong Hwan; (Seoul,
KR) ; HWANG; Seong Wook; (Gunpo-si, KR) ; KIM;
Jong Soo; (Seoul, KR) ; LEE; Chang Wook;
(Suwon-si, KR) ; CHO; Wonmin; (Hwaseong-si,
KR) ; KWON; Hyun Sik; (Seoul, KR) ; LEE.;
KyeongHun; (Seoul, KR) ; JI; Seongwook;
(Ansan-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company |
Seoul |
|
KR |
|
|
Assignee: |
Hyundai Motor Company
Seoul
KR
|
Family ID: |
58236789 |
Appl. No.: |
14/943466 |
Filed: |
November 17, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16H 2200/2012 20130101;
F16H 2200/2046 20130101; F16H 2200/0065 20130101; F16H 3/66
20130101 |
International
Class: |
F16H 3/66 20060101
F16H003/66 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2015 |
KR |
10-2015-0129863 |
Claims
1. A planetary gear train of an automatic transmission for a
vehicle, comprising: an input shaft receiving torque of an engine;
an output shaft outputting changed torque; a first planetary gear
set including a first rotation element, a second rotation element,
and a third rotation element; a second planetary gear set including
a fourth rotation element, a fifth rotation element, and a sixth
rotation element; a third planetary gear set including a seventh
rotation element, an eighth rotation element, and a ninth rotation
element; a fourth planetary gear set including a tenth rotation
element, an eleventh rotation element, and a twelfth rotation
element; and six friction elements disposed between at least one
rotation element among the twelve rotation elements and another
rotation element or a transmission housing, wherein the input shaft
is continuously connected to the second rotation element, the
output shaft is continuously connected to the eleventh rotation
element, the first rotation element is continuously connected to
the fourth rotation element, the fifth rotation element is
continuously connected to the eighth rotation element, the sixth
rotation element is continuously connected to the eleventh rotation
element, the ninth rotation element is continuously connected to
the tenth rotation element, the second rotation element is
selectively connected to the third rotation element, three friction
elements among the six friction elements are operated at each speed
stage.
2. The planetary gear train of claim 1, wherein the ninth rotation
element is selectively connected to the transmission housing, the
seventh rotation element is selectively connected to the
transmission housing, the third rotation element is selectively
connected to the twelfth rotation element, the third rotation
element is selectively connected to the fifth rotation element, the
first rotation element is selectively connected to the seventh
rotation element.
3. The planetary gear train of claim 1, wherein a sun gear, a
planet carrier, and a ring gear of the first planetary gear set are
set as the first rotation element, the second rotation element, and
the third rotation element, a sun gear, a planet carrier, and a
ring gear of the second planetary gear set are set as the fourth
rotation element, the fifth rotation element, and the sixth
rotation element, a sun gear, a planet carrier, and a ring gear of
the third planetary gear set are set as the seventh rotation
element, the eighth rotation element, and the ninth rotation
element, and a sun gear, a planet carrier, and a ring gear of the
fourth planetary gear set are set as the tenth, eleventh, and
twelfth rotation elements.
4. A planetary gear train of an automatic transmission for a
vehicle, comprising: an input shaft receiving torque of an engine;
an output shaft outputting changed torque; a first planetary gear
set including a first rotation element, a second rotation element,
and a third rotation element; a second planetary gear set including
a fourth rotation element, a fifth rotation element, and a sixth
rotation element; a third planetary gear set including a seventh
rotation element, an eighth rotation element, and a ninth rotation
element; a fourth planetary gear set including a tenth rotation
element, an eleventh rotation element, and a twelfth rotation
element; a first rotation shaft including the first rotation
element and the fourth rotation element; a second rotation shaft
including the second rotation element and directly connected to the
input shaft; a third rotation shaft including the third rotation
element and selectively connected to the second rotation shaft; a
fourth rotation shaft including the fifth rotation element and the
eighth rotation element and selectively connected to the third
rotation shaft; a fifth rotation shaft including the sixth rotation
element and the eleventh rotation element and directly connected to
the output shaft; a sixth rotation shaft including the seventh
rotation element and selectively connected to the first rotation
shaft and the transmission housing; a seventh rotation shaft
including the ninth rotation element and the tenth rotation element
and selectively connected to the transmission housing; and an
eighth rotation shaft including the twelfth rotation element and
selectively connected to the third rotation shaft.
5. The planetary gear train of claim 4, wherein the first planetary
gear set is a single pinion planetary gear set and includes a first
sun gear that is the first rotation element, a first planet carrier
that is the second rotation element, and a first ring gear that is
the third rotation element, the second planetary gear set is a
single pinion planetary gear set and includes a second sun gear
that is the fourth rotation element, a second planet carrier that
is the fifth rotation element, and a second ring gear that is the
sixth rotation element, the third planetary gear set is a single
pinion planetary gear set and includes a third sun gear that is the
seventh rotation element, a third planet carrier that is the eighth
rotation element, and a third ring gear that is the ninth rotation
element, and the fourth planetary gear set is a single pinion
planetary gear set and includes a fourth sun gear that is the tenth
rotation element, a fourth planet carrier that is the eleventh
rotation element, and a fourth ring gear that is the twelfth
rotation element.
6. The planetary gear train of claim 4, further comprising: a first
clutch disposed between the second rotation shaft and the third
rotation shaft; a second clutch disposed between the first rotation
shaft and the sixth rotation shaft; a third clutch disposed between
the third rotation shaft and the fourth rotation shaft; a fourth
clutch disposed between the third rotation shaft and the eighth
rotation shaft; a first brake disposed between the seventh rotation
shaft and the transmission housing; and a second brake disposed
between the sixth rotation shaft and the transmission housing.
7. The planetary gear train of claim 6, wherein a first forward
speed stage is achieved by operation of the first and second
clutches and the first brake, a second forward speed stage is
achieved by operation of the second and third clutches and the
first brake, a third forward speed stage is achieved by operation
of the third and fourth clutches and the first brake, a fourth
forward speed stage is achieved by operation of the first and
fourth clutches and the first brake, a fifth forward speed stage is
achieved by operation of the first, second, and fourth clutches, a
sixth forward speed stage is achieved by operation of the first and
fourth clutches and the second brake, a seventh forward speed stage
is achieved by operation of the third and fourth clutches and the
second brake, an eighth forward speed stage is achieved by
operation of the second and fourth clutches and the second brake, a
ninth forward speed stage is achieved by operation of the second
and third clutches and the second brake, a reverse speed stage is
achieved by operation of the first clutch and the first and second
brakes.
8. A planetary gear train of an automatic transmission for a
vehicle, comprising: an input shaft receiving torque of an engine;
an output shaft outputting changed torque; a first planetary gear
set including a first sun gear, a first planet carrier, and a first
ring gear; a second planetary gear set including a second sun gear,
a second planet carrier, and a second ring gear; a third planetary
gear set including a third sun gear, a third planet carrier, and a
third ring gear; a fourth planetary gear set including a fourth sun
gear, a fourth planet carrier, and a fourth ring gear; a first
rotation shaft including the first sun gear and the second sun
gear; a second rotation shaft including the first planet carrier
and directly connected to the input shaft; a third rotation shaft
including the first ring gear and selectively connected to the
second rotation shaft; a fourth rotation shaft including the second
planet carrier and the third planet carrier and selectively
connected to the third rotation shaft; a fifth rotation shaft
including the second ring gear and the third planet carrier and
directly connected to the output shaft; a sixth rotation shaft
including the third sun gear and selectively connected to the first
rotation shaft and a transmission housing; a seventh rotation shaft
including the third ring gear and the fourth sun gear and
selectively connected to the transmission housing; an eighth
rotation shaft including the fourth ring gear and selectively
connected to the third rotation shaft; and six friction elements
disposed between at least one rotation shaft among the eight
rotation shafts and another rotation shaft or the transmission
housing.
9. The planetary gear train of claim 8, wherein each of the first,
second, third, and fourth planetary gear sets is a single pinion
planetary gear set.
10. The planetary gear train of claim 8, wherein the six friction
elements include a first clutch disposed between the second
rotation shaft and the third rotation shaft; a second clutch
disposed between the first rotation shaft and the sixth rotation
shaft; a third clutch disposed between the third rotation shaft and
the fourth rotation shaft; a fourth clutch disposed between the
third rotation shaft and the eighth rotation shaft; a first brake
disposed between the seventh rotation shaft and the transmission
housing; and a second brake disposed between the sixth rotation
shaft and the transmission housing.
11. The planetary gear train of claim 10, wherein a first forward
speed stage is achieved by operation of the first and second
clutches and the first brake, a second forward speed stage is
achieved by operation of the second and third clutches and the
first brake, a third forward speed stage is achieved by operation
of the third and fourth clutches and the first brake, a fourth
forward speed stage is achieved by operation of the first and
fourth clutches and the first brake, a fifth forward speed stage is
achieved by operation of the first, second, and fourth clutches, a
sixth forward speed stage is achieved by operation of the first and
fourth clutches and the second brake, a seventh forward speed stage
is achieved by operation of the third and fourth clutches and the
second brake, an eighth forward speed stage is achieved by
operation of the second and fourth clutches and the second brake, a
ninth forward speed stage is achieved by operation of the second
and third clutches and the second brake, a reverse speed stage is
achieved by operation of the first clutch and the first and second
brakes.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to and the benefit
of Korean Patent Application No. 10-2015-0129863 filed on Sep. 14,
2015, the entire contents of which is incorporated herein for all
purposes by this reference.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention relates to a planetary gear train of
an automatic transmission for a vehicle. More particularly, the
present invention relates to a planetary gear train of an automatic
transmission for a vehicle which improves power delivery
performance and fuel efficiency as a consequence of achieving nine
forward or more speed stages using a minimum number of constituent
elements, enlarging a span of gear ratios, and linearly increasing
or decreasing step ratios between speed stages.
[0004] Description of Related Art
[0005] In recent years, a rise in oil price causes dashing into
unlimited competition for enhancing fuel efficiency.
[0006] As a result, a research into reduction of a weight and the
enhancement of the fuel efficiency through down sizing is conducted
in the case of an engine and a research for simultaneously securing
operability and fuel efficiency competitiveness through multiple
speed stages are conducted in the case of an automatic
transmission.
[0007] However, in the automatic transmission, as the number of
speed stages increases, the number of internal components increase,
and as a result, mountability, cost, weight, transmission
efficiency, and the like may still deteriorate.
[0008] Accordingly, development of a planetary gear train which may
bring about maximum efficiency with a small number of components
may be important in order to increase a fuel efficiency enhancement
effect through the multiple speed stages.
[0009] In this aspect, in recent years, 8-speed automatic
transmission tends to be implemented and the research and
development of a planetary gear train capable of implementing more
speed stages has also been actively conducted.
[0010] Since a span of gear ratios of the recent 8-speed automatic
transmission is merely 6.5 to 7.5, the 8-speed automatic
transmission has no great effect of improving fuel efficiency.
[0011] In addition, since step ratios between speed stages may not
be increased or decreased linearly in a case in which a span of
gear ratios of the 8-speed automatic transmission is greater than
or equal to 9.0, driving efficiency of an engine and drivability of
a vehicle may be deteriorated. Accordingly, there is a need for
development of a high efficient automatic transmission with 9 or
more forward speed stages.
[0012] The information disclosed in this Background of the
Invention section is only for enhancement of understanding of the
general background of the invention and should not be taken as an
acknowledgement or any form of suggestion that this information
forms the prior art already known to a person skilled in the
art.
BRIEF SUMMARY
[0013] Various aspects of the present invention are directed to
providing a planetary gear train of an automatic transmission for a
vehicle that improves power delivery performance and fuel
efficiency by achieving nine forward or more speed stages and one
reverse or more speed stage using a minimum number of constituent
elements, by enlarging a span of gear ratios, and by linearly
increasing or decreasing step ratios between speed stages.
[0014] An exemplary embodiment of the present invention provides a
planetary gear train of an automatic transmission for a vehicle
that may include an input shaft receiving torque of an engine; an
output shaft outputting changed torque; a first planetary gear set
including first, second, and third rotation elements; a second
planetary gear set including fourth, fifth, and sixth rotation
elements; a third planetary gear set including seventh, eighth, and
ninth rotation elements; a fourth planetary gear set including
tenth, eleventh, and twelfth rotation elements; and six friction
elements disposed between at least one rotation element among the
twelve rotation elements and another rotation element or a
transmission housing, wherein the input shaft is continuously
connected to the second rotation element, the output shaft is
continuously connected to the eleventh rotation element, the first
rotation element is continuously connected to the fourth rotation
element, the fifth rotation element is continuously connected to
the eighth rotation element, the sixth rotation element is
continuously connected to the eleventh rotation element, the ninth
rotation element is continuously connected to the tenth rotation
element, the second rotation element is selectively connected to
the third rotation element, three friction elements among the six
friction elements are operated at each speed stage.
[0015] The ninth rotation element may be selectively connected to
the transmission housing, the seventh rotation element may be
selectively connected to the transmission housing, the third
rotation element may be selectively connected to the twelfth
rotation element, the third rotation element may be selectively
connected to the fifth rotation element, the first rotation element
may be selectively connected to the seventh rotation element.
[0016] A sun gear, a planet carrier, and a ring gear of the first
planetary gear set may be set as the first, second, and third
rotation elements, a sun gear, a planet carrier, and a ring gear of
the second planetary gear set may be set as the fourth, fifth, and
sixth rotation elements, a sun gear, a planet carrier, and a ring
gear of the third planetary gear set may be set as the seventh,
eighth, and ninth rotation elements, and a sun gear, a planet
carrier, and a ring gear of the fourth planetary gear set may be
set as the tenth, eleventh, and twelfth rotation elements.
[0017] Another exemplary embodiment of the present invention
provides a planetary gear train of an automatic transmission for a
vehicle that may include an input shaft receiving torque of an
engine; an output shaft outputting changed torque; a first
planetary gear set including first, second, and third rotation
elements; a second planetary gear set including fourth, fifth, and
sixth rotation elements; a third planetary gear set including
seventh, eighth, and ninth rotation elements; a fourth planetary
gear set including tenth, eleventh, and twelfth rotation elements;
a first rotation shaft including the first rotation element and the
fourth rotation element; a second rotation shaft including the
second rotation element and directly connected to the input shaft;
a third rotation shaft including the third rotation element and
selectively connected to the second rotation shaft; a fourth
rotation shaft including the fifth rotation element and the eighth
rotation element and selectively connected to the third rotation
shaft; a fifth rotation shaft including the sixth rotation element
and the eleventh rotation element and directly connected to the
output shaft; a sixth rotation shaft including the seventh rotation
element and selectively connected to the first rotation shaft and
the transmission housing; a seventh rotation shaft including the
ninth rotation element and the tenth rotation element and
selectively connected to the transmission housing; and an eighth
rotation shaft including the twelfth rotation element and
selectively connected to the third rotation shaft.
[0018] The first planetary gear set may be a single pinion
planetary gear set and may include a first sun gear that is the
first rotation element, a first planet carrier that is the second
rotation element, and a first ring gear that is the third rotation
element, the second planetary gear set may be a single pinion
planetary gear set and may include a second sun gear that is the
fourth rotation element, a second planet carrier that is the fifth
rotation element, and a second ring gear that is the sixth rotation
element, the third planetary gear set may be a single pinion
planetary gear set and may include a third sun gear that is the
seventh rotation element, a third planet carrier that is the eighth
rotation element, and a third ring gear that is the ninth rotation
element, and the fourth planetary gear set may be a single pinion
planetary gear set and may include a fourth sun gear that is the
tenth rotation element, a fourth planet carrier that is the
eleventh rotation element, and a fourth ring gear that is the
twelfth rotation element.
[0019] The planetary gear train may further include a first clutch
disposed between the second rotation shaft and the third rotation
shaft; a second clutch disposed between the first rotation shaft
and the sixth rotation shaft; a third clutch disposed between the
third rotation shaft and the fourth rotation shaft; a fourth clutch
disposed between the third rotation shaft and the eighth rotation
shaft; a first brake disposed between the seventh rotation shaft
and the transmission housing; and a second brake disposed between
the sixth rotation shaft and the transmission housing.
[0020] A first forward speed stage may be achieved by operation of
the first and second clutches and the first brake, a second forward
speed stage may be achieved by operation of the second and third
clutches and the first brake, a third forward speed stage may be
achieved by operation of the third and fourth clutches and the
first brake, a fourth forward speed stage may be achieved by
operation of the first and fourth clutches and the first brake, a
fifth forward speed stage may be achieved by operation of the
first, second, and fourth clutches, a sixth forward speed stage may
be achieved by operation of the first and fourth clutches and the
second brake, a seventh forward speed stage may be achieved by
operation of the third and fourth clutches and the second brake, an
eighth forward speed stage may be achieved by operation of the
second and fourth clutches and the second brake, a ninth forward
speed stage may be achieved by operation of the second and third
clutches and the second brake, a reverse speed stage may be
achieved by operation of the first clutch and the first and second
brakes.
[0021] Yet another exemplary embodiment of the present invention
provides a planetary gear train of an automatic transmission for a
vehicle that may include an input shaft receiving torque of an
engine; an output shaft outputting changed torque; a first
planetary gear set including a first sun gear, a first planet
carrier, and a first ring gear; a second planetary gear set
including a second sun gear, a second planet carrier, and a second
ring gear; a third planetary gear set including a third sun gear, a
third planet carrier, and a third ring gear; a fourth planetary
gear set including a fourth sun gear, a fourth planet carrier, and
a fourth ring gear; a first rotation shaft including the first sun
gear and the second sun gear; a second rotation shaft including the
first planet carrier and directly connected to the input shaft; a
third rotation shaft including the first ring gear and selectively
connected to the second rotation shaft; a fourth rotation shaft
including the second planet carrier and the third planet carrier
and selectively connected to the third rotation shaft; a fifth
rotation shaft including the second ring gear and the third planet
carrier and directly connected to the output shaft; a sixth
rotation shaft including the third sun gear and selectively
connected to the first rotation shaft and a transmission housing; a
seventh rotation shaft including the third ring gear and the fourth
sun gear and selectively connected to the transmission housing; an
eighth rotation shaft including the fourth ring gear and
selectively connected to the third rotation shaft; and six friction
elements disposed between at least one rotation shaft among the
eight rotation shafts and another rotation shaft or the
transmission housing.
[0022] Each of the first, second, third, and fourth planetary gear
sets may be a single pinion planetary gear set.
[0023] The six friction elements may include a first clutch
disposed between the second rotation shaft and the third rotation
shaft; a second clutch disposed between the first rotation shaft
and the sixth rotation shaft; a third clutch disposed between the
third rotation shaft and the fourth rotation shaft; a fourth clutch
disposed between the third rotation shaft and the eighth rotation
shaft; a first brake disposed between the seventh rotation shaft
and the transmission housing; and a second brake disposed between
the sixth rotation shaft and the transmission housing.
[0024] A first forward speed stage may be achieved by operation of
the first and second clutches and the first brake, a second forward
speed stage may be achieved by operation of the second and third
clutches and the first brake, a third forward speed stage may be
achieved by operation of the third and fourth clutches and the
first brake, a fourth forward speed stage may be achieved by
operation of the first and fourth clutches and the first brake, a
fifth forward speed stage may be achieved by operation of the
first, second, and fourth clutches, a sixth forward speed stage may
be achieved by operation of the first and fourth clutches and the
second brake, a seventh forward speed stage may be achieved by
operation of the third and fourth clutches and the second brake, an
eighth forward speed stage may be achieved by operation of the
second and fourth clutches and the second brake, a ninth forward
speed stage may be achieved by operation of the second and third
clutches and the second brake, a reverse speed stage may be
achieved by operation of the first clutch and the first and second
brakes.
[0025] An exemplary embodiment of the present invention may achieve
nine forward speed stages and one reverse speed stage by combining
four planetary gear sets that are simple planetary gear sets with
six friction elements.
[0026] In addition, engine driving efficiency may be maximized by
achieving a span of gear ratios to be greater than or equal to
8.0.
[0027] In addition, drivability such as acceleration before and
after the shift and rhythm of engine speed may be improved by
linearly increasing or decreasing step ratios between speed
stages.
[0028] Further, effects that can be obtained or expected from
exemplary embodiments of the present invention are directly or
suggestively described in the following detailed description. That
is, various effects expected from exemplary embodiments of the
present invention will be described in the following detailed
description.
[0029] The methods and apparatuses of the present invention have
other features and advantages which will be apparent from or are
set forth in more detail in the accompanying drawings, which are
incorporated herein, and the following Detailed Description, which
together serve to explain certain principles of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a schematic diagram of a planetary gear train
according to an exemplary embodiment of the present invention.
[0031] FIG. 2 is an operation chart of friction elements at each
speed stage in the planetary gear train according to an exemplary
embodiment of the present invention.
[0032] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various features illustrative of the basic
principles of the invention. The specific design features of the
present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
[0033] In the figures, reference numbers refer to the same or
equivalent parts of the present invention throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0034] Reference will now be made in detail to various embodiments
of the present invention(s), examples of which are illustrated in
the accompanying drawings and described below. While the
invention(s) will be described in conjunction with exemplary
embodiments, it will be understood that the present description is
not intended to limit the invention(s) to those exemplary
embodiments. On the contrary, the invention(s) is/are intended to
cover not only the exemplary embodiments, but also various
alternatives, modifications, equivalents and other embodiments,
which may be included within the spirit and scope of the invention
as defined by the appended claims.
[0035] However, parts which are not related with the description
are omitted for clearly describing the exemplary embodiment of the
present invention and like reference numerals refer to like or
similar elements throughout the specification.
[0036] In the following description, dividing names of components
into first, second, and the like is to divide the names because the
names of the components are the same as each other and an order
thereof is not particularly limited.
[0037] FIG. 1 is a schematic diagram of a planetary gear train
according to an exemplary embodiment of the present invention.
[0038] Referring to FIG. 1, a planetary gear train according to an
exemplary embodiment of the present invention includes first,
second, third, fourth planetary gear sets PG1, PG2, PG3, and PG4
disposed on the same axis, an input shaft IS, an output shaft OS,
eight rotations shafts TM1 to TM8 including at least one rotation
elements of the first, second, third, and fourth planetary gear
sets PG1, PG2, PG3, and PG4, six friction elements C1 to C4 and B1
to B2, and a transmission housing H.
[0039] As a result, torque input from the input shaft IS is changed
by cooperation of the first, second, third, and fourth planetary
gear sets PG1, PG2, PG3, and PG4, and the changed torque is output
through the output shaft OS.
[0040] The planetary gear sets PG1, PG2, PG3, and PG4 are disposed
sequentially from an engine side.
[0041] The input shaft IS is an input member and power from a
crankshaft of an engine is torque-converted through a torque
converter to be input into the input shaft IS.
[0042] The output shaft OS is an output member, is disposed in
parallel with the input shaft IS, and transmits driving torque to a
driving wheel through a differential apparatus.
[0043] The first planetary gear set PG1 is a single pinion
planetary gear set and includes a first sun gear S1 of a first
rotation element N1, a first planet carrier PCI of a second
rotation element N2 rotatably supporting a first pinion P1
externally engaged the first sun gear S1, and a first ring gear R1
of a third rotation element N3 internally engaged with the first
pinion P1.
[0044] The second planetary gear set PG2 is a single pinion
planetary gear set and includes a second sun gear S2 of a fourth
rotation element N4, a second planet carrier PC2 of a fifth
rotation element N5 rotatably supporting a second pinion P2
externally engaged the second sun gear S2, and a second ring gear
of a sixth rotation element N6 internally engaged with the second
pinion P2.
[0045] The third planetary gear set PG3 is a single pinion
planetary gear set and includes a third sun gear S3 of a seventh
rotation element N7, a third planet carrier PC3 of an eighth
rotation element N8 rotatably supporting a third pinion P3
externally engaged with the third sun gear S3, and a third ring
gear R3 of a ninth rotation element N9 internally engaged with the
third pinion P3.
[0046] The fourth planetary gear set PG4 is a single pinion
planetary gear set and includes a fourth sun gear S4 of a tenth
rotation element N10, a fourth planet carrier PC4 of an eleventh
rotation element N11 rotatably supporting a fourth pinion P4
externally engaged with the fourth sungear S4, and a fourth ring
gear R4 of a twelfth rotation element N12 internally engaged with
the fourth pinion P4.
[0047] The first rotation element N1 is directly connected to the
fourth rotation element N4, the fifth rotation element N5 is
directly connected to the eighth rotation element N8, the sixth
rotation element N6 is directly connected to the eleventh rotation
element N11, the ninth rotation element N9 is directly connected to
the tenth rotation element N10, and the first, second, third, and
fourth planetary gear sets PG1, PG2, PG3, and PG4 are operated with
eight rotation shafts TM1 to TM8.
[0048] The eight rotation shafts TM1 to TM8 will be described in
further detail.
[0049] The first rotation shaft TM1 includes the first rotation
element N1, and the fourth rotation element N4.
[0050] The second rotation shaft TM2 includes the second rotation
element N2, and is directly connected to the input shaft IS so as
to be continuously operated as an input element.
[0051] The third rotation shaft TM3 includes the third rotation
element N3, and is selectively connected to the second rotation
shaft TM2.
[0052] The fourth rotation shaft TM4 includes the fifth rotation
element N5 and the eighth rotation element N8, and is selectively
connected to the third rotation shaft TM3.
[0053] The fifth rotation shaft TM5 includes the sixth rotation
element N6 and the eleventh rotation element N11, and is directly
connected to the output shaft OS so as to be continuously operated
as an output element.
[0054] The sixth rotation shaft TM6 includes the seventh rotation
element N7, is selectively connected to the first rotation shaft
TM1, and is selectively connected to the transmission housing
H.
[0055] The seventh rotation shaft TM7 includes the ninth rotation
element N9 and the tenth rotation element N10, and is selectively
connected to the transmission housing H.
[0056] The eighth rotation shaft TM8 includes the twelfth rotation
element N12, and is selectively connected to the third rotation
shaft TM3.
[0057] In addition, four clutches C1, C2, C3, and C4 which are
friction elements are disposed at connection portions between any
two rotation shafts.
[0058] In addition, two brakes B1 and B2 which are friction
elements are disposed at connection portions between any one
rotation shaft and the transmission housing H.
[0059] The six friction elements C1 to C4 and B1 to B2 will be
described in further detail.
[0060] The first clutch C1 is disposed between the second rotation
shaft TM2 and the third rotation shaft TM3 and selectively connects
the second rotation shaft TM2 and the third rotation shaft TM3.
[0061] The second clutch C2 is disposed between the first rotation
shaft TM1 and the sixth rotation shaft TM6 and selectively connects
the first rotation shaft TM1 and the sixth rotation shaft TM6.
[0062] The third clutch C3 is disposed between the third rotation
shaft TM3 and the fourth rotation shaft TM4 and selectively
connects the third rotation shaft TM3 and the fourth rotation shaft
TM4.
[0063] The fourth clutch C4 is disposed between the third rotation
shaft TM3 and the eighth rotation shaft TM8 and selectively
connects the third rotation shaft TM3 and the eighth rotation shaft
TM8.
[0064] The first brake B1 is disposed between the seventh rotation
shaft TM7 and the transmission housing H and causes the seventh
rotation shaft TM7 to be operated as a selective fixed element.
[0065] The second brake B2 is disposed between the sixth rotation
shaft TM6 and the transmission housing H and causes the sixth
rotation shaft TM6 to be operated as a selective fixed element.
[0066] The friction elements including the first, second, third,
and fourth clutches C1, C2, C3, and C4 and the first and second
brakes B1 and B2 may be multi-plates friction elements of wet type
that are operated by hydraulic pressure.
[0067] FIG. 2 is an operation chart of friction elements at each
speed stage in the planetary gear train according to an exemplary
embodiment of the present invention.
[0068] As shown in FIG. 2, three friction elements are operated at
each speed stage in the planetary gear train according to an
exemplary embodiment of the present invention. Shifting processes
in the exemplary embodiment of the present invention will be
described in further detail.
[0069] If the first and second clutch C1 and C2 and the first brake
B1 are operated at a first forward speed stage D1, the second
rotation shaft TM2 is connected to the third rotation shaft TM3,
the first rotation shaft TM1 is connected to the sixth rotation
shaft TM6, rotation speed of the input shaft IS is input to the
second rotation shaft TM2, and the seventh rotation shaft TM7 is
operated as the fixed element. Therefore, the first forward speed
stage is achieved.
[0070] If the second and third clutches C2 and C3 and the first
brake B1 are operated at a second forward speed stage D2, the first
rotation shaft TM1 is connected to the sixth rotation shaft TM6,
the third rotation shaft TM3 is connected to the fourth rotation
shaft TM4, rotation speed of the input shaft IS is input to the
second rotation shaft TM2, and the seventh rotation shaft TM7 is
operated as the fixed element. Therefore, the second forward speed
stage is achieved.
[0071] If the third and fourth clutches C3 and C4 and the first
brake B1 are operated at a third forward speed stage D3, the third
rotation shaft TM3 is connected to the fourth rotation shaft TM4,
the third rotation shaft TM3 is connected to the eighth rotation
shaft TM8, rotation speed of the input shaft IS is input to the
second rotation shaft TM2, and the seventh rotation shaft TM7 is
operated as the fixed element. Therefore, the third forward speed
stage is achieved.
[0072] If the first and fourth clutch C1 and C4 and the first brake
B1 are operated at a fourth forward speed stage D4, the second
rotation shaft TM2 is connected to the third rotation shaft TM3,
the third rotation shaft TM3 is connected to the eighth rotation
shaft TM8, rotation speed of the input shaft IS is input to the
second rotation shaft TM2, and the seventh rotation shaft TM7 is
operated as the fixed element. Therefore, the fourth forward speed
stage is achieved.
[0073] If the first, second and fourth clutches C1, C2 and C4 are
operated at a fifth forward speed stage D5, the second rotation
shaft TM2 is connected to the third rotation shaft TM3, the first
rotation shaft TM1 is connected to the sixth rotation shaft TM6,
and the third rotation shaft TM3 is connected to the eighth
rotation shaft TM8. Therefore, all the planetary gear sets become
direct-coupling states. At this state, if rotation speed of the
input shaft IS is input to the second rotation shaft TM2, the fifth
forward speed stage is achieved. At the fifth forward speed stage,
rotation speed that is the same as that of the input shaft IS is
output.
[0074] If the first and fourth clutches C1 and C4 and the second
brake B2 are operated at a sixth forward speed stage D6, the second
rotation shaft TM2 is connected to the third rotation shaft TM3,
the third rotation shaft TM3 is connected to the eighth rotation
shaft TM8, rotation speed of the input shaft IS is input to the
second rotation shaft TM2, and the sixth rotation shaft TM6 is
operated as the fixed element. Therefore, the sixth forward speed
stage is achieved.
[0075] If the third and fourth clutches C3 and C4 and the second
brake B2 are operated at a seventh forward speed stage D7, the
third rotation shaft TM3 is connected to the fourth rotation shaft
TM4, the third rotation shaft TM3 is connected to the eighth
rotation shaft TM8, rotation speed of the input shaft IS is input
to the second rotation shaft TM2, and the sixth rotation shaft TM6
is operated as the fixed element. Therefore, the seventh forward
speed stage is achieved.
[0076] If the second and fourth clutches C2 and C4 and the second
brake B2 are operated at an eighth forward speed stage D8, the
first rotation shaft TM1 is connected to the sixth rotation shaft
TM6, the third rotation shaft TM3 is connected to the eighth
rotation shaft TM8, rotation speed of the input shaft IS is input
to the second rotation shaft TM2, and the sixth rotation shaft TM6
is operated as the fixed element. Therefore, the eighth forward
speed stage is achieved.
[0077] If the second and third clutches C2 and C3 and the second
brake B2 are operated at a ninth forward speed stage D9, the first
rotation shaft TM1 is connected to the sixth rotation shaft TM6,
the third rotation shaft TM3 is connected to the fourth rotation
shaft TM4, rotation speed of the input shaft IS is input to the
second rotation shaft TM2, and the sixth rotation shaft TM6 is
operated as the fixed element. Therefore, the ninth forward speed
stage is achieved.
[0078] If the first clutch C1 and first and second brakes B1 and B2
are operated at a reverse speed stage REV, the second rotation
shaft TM2 is connected to the third rotation shaft TM3, rotation
speed of the input shaft IS is input to the second rotation shaft
TM2, and the seventh rotation shaft TM7 and the sixth rotation
shaft TM6 are operated as the fixed elements. Therefore, the
reverse speed stage is achieved.
[0079] The planetary gear train according to an exemplary
embodiment of the present invention may achieve nine forward speed
stages and one reverse speed stage by controlling four planetary
gear sets PG1, PG2, PG3, and PG4 with four clutches C1, C2, C3, and
C4 and tow brakes B1 and B2.
[0080] In addition, step ratios between speed stages are 1.2 or
more except for between the sixth and seventh forward speed stages,
between the seventh and eighth forward speed stages, and between
the eighth and ninth forward speed stages, and linearity of step
ratios between speed stages can be secured. Thus, drivability such
as acceleration before and after the shift and rhythm of engine
speed may be improved.
[0081] In addition, engine driving efficiency may be maximized by
achieving a span of gear ratios to be near to 9.0.
[0082] For convenience in explanation and accurate definition in
the appended claims, the terms "upper", "lower", "inner" and
"outer" are used to describe features of the exemplary embodiments
with reference to the positions of such features as displayed in
the figures.
[0083] The foregoing descriptions of specific exemplary embodiments
of the present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations are
possible in light of the above teachings. The exemplary embodiments
were chosen and described in order to explain certain principles of
the invention and their practical application, to thereby enable
others skilled in the art to make and utilize various exemplary
embodiments of the present invention, as well as various
alternatives and modifications thereof. It is intended that the
scope of the invention be defined by the Claims appended hereto and
their equivalents.
* * * * *