U.S. patent application number 14/941344 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 Woo Jin CHANG, Wonmin CHO, Seong Wook HWANG, Seongwook JI, Jae Chang KOOK, Hyun Sik KWON.
Application Number | 20170074360 14/941344 |
Document ID | / |
Family ID | 58163454 |
Filed Date | 2017-03-16 |
United States Patent
Application |
20170074360 |
Kind Code |
A1 |
CHO; Wonmin ; 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 receiving torque of an engine,
an output shaft outputting changed torque of the engine, a first
planetary gear set including first, second, and third rotation
elements, a second planetary gear set including fourth, fifth, and
sixth rotation elements, and a third planetary gear set including
seventh, eighth, and ninth rotation elements.
Inventors: |
CHO; Wonmin; (Hwaseong-si,
KR) ; HWANG; Seong Wook; (Gunpo-si, KR) ;
CHANG; Woo Jin; (Suwon-si, KR) ; KWON; Hyun Sik;
(Seoul, KR) ; KOOK; Jae Chang; (Hwaseong-si,
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: |
58163454 |
Appl. No.: |
14/941344 |
Filed: |
November 13, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16H 2200/2046 20130101;
F16H 3/66 20130101; F16H 2200/2097 20130101; F16H 2200/006
20130101; F16H 2200/201 20130101; F16H 2003/445 20130101 |
International
Class: |
F16H 3/66 20060101
F16H003/66 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2015 |
KR |
10-2015-0129860 |
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 of the engine; a first
planetary gear set including first, second, and third rotation
elements; a second planetary gear set including fourth, fifth, and
sixth rotation elements; and a third planetary gear set including
seventh, eighth, and ninth rotation elements, wherein: the first
rotation element is directly connected to the seventh rotation
element, the second rotation element is directly connected to the
ninth rotation element, the fourth rotation element is directly
connected to a transmission housing, the eighth rotation element is
directly connected to the output shaft, the input shaft is
selectively connected respectively to the first rotation element
and the fifth rotation element, the second rotation element is
selectively connected to the sixth rotation element, the third
rotation element is selectively connected to the fifth rotation
element and the sixth rotation element, respectively, and the ninth
rotation element is selectively connected to the transmission
housing.
2. The planetary gear train of claim 1, wherein the first, second,
and third rotation elements of the first planetary gear set are a
first sun gear, a first planet carrier, and a first ring gear, the
fourth, fifth, and sixth rotation elements are a second sun gear, a
second planet carrier, and a second ring gear, and the seventh,
eighth, and ninth rotation elements are a third sun gear, a third
planet carrier, and a third ring gear.
3. The planetary gear train of claim 2, wherein each of the first,
second, and third planetary gear sets comprises a single pinion
planetary gear set.
4. The planetary gear train of claim 1, further comprising: a first
clutch selectively connecting the input shaft to the first rotation
element; a second clutch selectively connecting the input shaft to
the fifth rotation element; a third clutch selectively connecting
the second rotation element to the sixth rotation element; a fourth
clutch selectively connecting the third rotation element to the
fifth rotation element; a fifth clutch selectively connecting the
third rotation element to the sixth rotation element; and a first
brake selectively connecting the ninth rotation element to the
transmission housing.
5. The planetary gear train of claim 4, wherein the first and
fourth clutches and the first brake are operated at a first forward
speed stage, the first, fourth, and fifth clutches are operated at
a second forward speed stage, the first, third, and fourth clutches
are operated at a third forward speed stage, the first, second, and
fourth clutches are operated at a fourth forward speed stage, the
first, second, and fifth clutches are operated at a fifth forward
speed stage, the first, second, and third clutches are operated at
a sixth forward speed stage, the second, third, and fifth clutches
are operated at a seventh forward speed stage, the second, third,
and fourth clutches are operated at an eighth forward speed stage,
and the second and fourth clutches and the first brake are operated
at a reverse speed stage.
6. 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 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 first rotation shaft connecting the
first rotation element to the seventh rotation element and
selectively connected to the input shaft; a second rotation shaft
connecting the second rotation element to the ninth rotation
element and selectively connected to a transmission housing; a
third rotation shaft connected to the third rotation element; a
fourth rotation shaft connected to the fourth rotation element and
directly connected to the transmission housing; a fifth rotation
shaft connected to the fifth rotation element and selectively
connected to the input shaft and the third rotation shaft,
respectively; a sixth rotation shaft connected to the sixth
rotation element and selectively connected to the second rotation
shaft and the third rotation shaft, respectively; and a seventh
rotation shaft connected to the eighth rotation element and
directly connected to the output shaft.
7. The planetary gear train of claim 6, wherein the first planetary
gear set comprises a single pinion planetary gear set and includes
a first sun gear as the first rotation element, a first planet
carrier as the second rotation element, and a first ring gear as
the third rotation element, the second planetary gear set comprises
a single pinion planetary gear set and includes a second sun gear
as the fourth rotation element, a second planet carrier as the
fifth rotation element, and a second ring gear as the sixth
rotation element, and the third planetary gear set comprises a
single pinion planetary gear set and includes a third sun gear as
the seventh rotation element, a third planet carrier as the eighth
rotation element, and a third ring gear as the ninth rotation
element.
8. The planetary gear train of claim 6, further comprising: a first
clutch selectively connecting the input shaft to the first rotation
shaft; a second clutch selectively connecting the input shaft to
the fifth rotation shaft; a third clutch selectively connecting the
second rotation shaft to the sixth rotation shaft; a fourth clutch
selectively connecting the third rotation shaft to the fifth
rotation shaft; a fifth clutch selectively connecting the third
rotation shaft to the sixth rotation shaft; and a first brake
selectively connecting the second rotation shaft to the
transmission housing.
9. The planetary gear train of claim 8, wherein the first and
fourth clutches and the first brake are operated at a first forward
speed stage, the first, fourth, and fifth clutches are operated at
a second forward speed stage, the first, third, and fourth clutches
are operated at a third forward speed stage, the first, second, and
fourth clutches are operated at a fourth forward speed stage, the
first, second, and fifth clutches are operated at a fifth forward
speed stage, the first, second, and third clutches are operated at
a sixth forward speed stage, the second, third, and fifth clutches
are operated at a seventh forward speed stage, the second, third,
and fourth clutches are operated at an eighth forward speed stage,
and the second and fourth clutches and the first brake are operated
at a reverse speed stage.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to Korean Patent
Application No. 10-2015-0129860, filed 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 an automatic transmission
for a vehicle. More particularly, the present invention relates to
a planetary gear train of an automatic transmission for a vehicle
that improves fuel economy by achieving eight forward speed stages
using a minimum number of constituent elements and improves silent
driving by using operation point at a low RPM region.
[0004] Description of Related Art
[0005] In recent years, a rise in oil price caused unlimited
competition for enhancing fuel efficiency.
[0006] As a result, research is being conducted on engines in terms
of reducing weight and improving fuel efficiency by down-sizing,
and research is also being conducted for simultaneously securing
operability and fuel efficiency competitiveness by implementing an
automatic transmission with multiple speed stages.
[0007] However, in the automatic transmission, as the number of
speed stages increase, the number of internal components increase,
and as a result, the automatic transmission may be difficult to
mount, the manufacturing cost and weight may be increased, and
power transmission efficiency may be deteriorated.
[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
transmissions tend 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] 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
[0011] Various aspects of the present invention are directed to
providing a planetary gear train of an automatic transmission for a
vehicle having advantages of improving fuel economy by achieving
eight forward speed stages and one reverse speed stage and of
improving silent driving of the vehicle by using operation point
positioned at a low RPM region.
[0012] According to various aspects of the present invention, a
planetary gear train of an automatic transmission for a vehicle may
include an input shaft receiving torque of an engine, an output
shaft outputting changed torque of the engine, a first planetary
gear set including first, second, and third rotation elements, a
second planetary gear set including fourth, fifth, and sixth
rotation elements, and a third planetary gear set including
seventh, eighth, and ninth rotation elements, in which the first
rotation element may be directly connected to the seventh rotation
element, the second rotation element may be directly connected to
the ninth rotation element, the fourth rotation element may be
directly connected to a transmission housing, the eighth rotation
element may be directly connected to the output shaft, the input
shaft may be selectively connected respectively to the first
rotation element and the fifth rotation element, the second
rotation element may be selectively connected to the sixth rotation
element, the third rotation element may be selectively connected to
the fifth rotation element and the sixth rotation element,
respectively, and the ninth rotation element may be selectively
connected to the transmission housing.
[0013] The first, second, and third rotation elements of the first
planetary gear set may be a first sun gear, a first planet carrier,
and a first ring gear, the fourth, fifth, and sixth rotation
elements may be a second sun gear, a second planet carrier, and a
second ring gear, and the seventh, eighth, and ninth rotation
elements may be a third sun gear, a third planet carrier, and a
third ring gear.
[0014] Each of the first, second, and third planetary gear sets may
be a single pinion planetary gear set.
[0015] The planetary gear train may further include a first clutch
selectively connecting the input shaft to the first rotation
element, a second clutch selectively connecting the input shaft to
the fifth rotation element, a third clutch selectively connecting
the second rotation element to the sixth rotation element, a fourth
clutch selectively connecting the third rotation element to the
fifth rotation element, a fifth clutch selectively connecting the
third rotation element to the sixth rotation element, and a first
brake selectively connecting the ninth rotation element to the
transmission housing.
[0016] According to various aspects of the present invention, a
planetary gear train of an automatic transmission for a vehicle 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 first rotation shaft connecting the
first rotation element to the seventh rotation element and
selectively connected to the input shaft, a second rotation shaft
connecting the second rotation element to the ninth rotation
element and selectively connected to a transmission housing, a
third rotation shaft connected to the third rotation element, a
fourth rotation shaft connected to the fourth rotation element and
directly connected to the transmission housing, a fifth rotation
shaft connected to the fifth rotation element and selectively
connected to the input shaft and the third rotation shaft,
respectively, a sixth rotation shaft connected to the sixth
rotation element and selectively connected to the second rotation
shaft and the third rotation shaft, respectively, and a seventh
rotation shaft connected to the eighth rotation element and
directly connected to the output shaft.
[0017] The first planetary gear set may be a single pinion
planetary gear set and include a first sun gear as the first
rotation element, a first planet carrier as the second rotation
element, and a first ring gear as the third rotation element, the
second planetary gear set may be a single pinion planetary gear set
and include a second sun gear as the fourth rotation element, a
second planet carrier as the fifth rotation element, and a second
ring gear as the sixth rotation element, and the third planetary
gear set may be a single pinion planetary gear set and include a
third sun gear as the seventh rotation element, a third planet
carrier as the eighth rotation element, and a third ring gear as
the ninth rotation element.
[0018] The planetary gear train may further include a first clutch
selectively connecting the input shaft to the first rotation shaft,
a second clutch selectively connecting the input shaft to the fifth
rotation shaft, a third clutch selectively connecting the second
rotation shaft to the sixth rotation shaft, a fourth clutch
selectively connecting the third rotation shaft to the fifth
rotation shaft, a fifth clutch selectively connecting the third
rotation shaft to the sixth rotation shaft, and a first brake
selectively connecting the second rotation shaft to the
transmission housing.
[0019] The first and fourth clutches and the first brake may be
operated at a first forward speed stage, the first, fourth, and
fifth clutches may be operated at a second forward speed stage, the
first, third, and fourth clutches may be operated at a third
forward speed stage, the first, second, and fourth clutches may be
operated at a fourth forward speed stage, the first, second, and
fifth clutches may be operated at a fifth forward speed stage, the
first, second, and third clutches may be operated at a sixth
forward speed stage, the second, third, and fifth clutches may be
operated at a seventh forward speed stage, the second, third, and
fourth clutches may be operated at an eighth forward speed stage,
and the second and fourth clutches and the first brake may be
operated at a reverse speed stage.
[0020] Various embodiments of the present invention may achieve
eight forward speed stages and one reverse speed stage by combining
three planetary gear sets with six control elements.
[0021] In addition, since eight forward speed stages are achieved
by using three planetary gear sets, an internal structure of the
automatic transmission may be simplified and durability may be
improved.
[0022] Since fuel economy is improved due to achievement of
multiple speed stages and operation point at low RPM regions is
used, silent driving of the vehicle may be improved.
[0023] Further, effects obtained or predicted by the various
embodiments of the present invention will be directly or
suggestively described in the detailed description section. That
is, various effects predicted according to the various embodiments
of the present invention will be described in further detail in the
detailed description section.
[0024] It is understood that the term "vehicle" or "vehicular" or
other similar terms as used herein is inclusive of motor vehicles
in general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats and ships, aircraft, and
the like, and includes hybrid vehicles, electric vehicles, plug-in
hybrid electric vehicles, hydrogen-powered vehicles and other
alternative fuel vehicles (e.g., fuel derived from resources other
than petroleum). As referred to herein, a hybrid vehicle is a
vehicle that has two or more sources of power, for example, both
gasoline-powered and electric-powered vehicles.
[0025] 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
[0026] FIG. 1 is a schematic diagram of an exemplary planetary gear
train according to the present invention.
[0027] FIG. 2 is an operation chart of control elements at each
speed stage in the exemplary planetary gear train according to the
present invention.
[0028] 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.
DETAILED DESCRIPTION
[0029] 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.
[0030] FIG. 1 is a schematic diagram of a planetary gear train
according to various embodiments of the present invention.
[0031] Referring to FIG. 1, a planetary gear train according to
various embodiments of the present invention includes first,
second, and third planetary gear sets PG1, PG2, and PG3 disposed on
the same axis, an input shaft IS, an output shaft OS, seven
rotation shafts TM1 to TM7 connected to at least one of rotation
elements of the first, second, and third planetary gear sets PG1,
PG2, and PG3, six control elements C1 to C5, and B1, and a
transmission housing H.
[0032] As a result, torque input from the input shaft IS is changed
by cooperation of the first, second, and third planetary gear sets
PG1, PG2, and PG3, and the changed torque is output through the
output shaft OS.
[0033] The simple planetary gear sets are disposed in a sequence of
the first, second, and third planetary gear sets PG1, PG2, and PG3
from an engine side.
[0034] 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.
[0035] 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.
[0036] The first planetary gear set PG1 is a single pinion
planetary gear set and includes a first sun gear S1, a first planet
carrier PC1 rotatably supporting a first pinion P1 that is
externally meshed with the first sun gear S1, and a first ring gear
R1 that is internally meshed with the first pinion P1 respectively
as first, second, and third rotation elements N1, N2, and N3.
[0037] The second planetary gear set PG2 is a single pinion
planetary gear set and includes a second sun gear S2, a second
planet carrier PC2 rotatably supporting a second pinion P2 that is
externally meshed with the second sun gear S2, and a second ring
gear R2 that is internally meshed with the second pinion P2
respectively as fourth, fifth, and sixth rotation elements N4, N5,
and N6.
[0038] The third planetary gear set PG3 is a single pinion
planetary gear set and includes a third sun gear S3, a third planet
carrier PC3 rotatably supporting a third pinion P3 that is
externally meshed with the third sun gear S3, and a third ring gear
R3 that is internally meshed with the third pinion P3 respectively
as seventh, eighth, and ninth rotation elements N7, N8, and N9.
[0039] The first rotation element N1 is directly connected to the
seventh rotation element N7 and the second rotation element N2 is
directly connected to the ninth rotation element N9 such that the
first, second, and third planetary gear sets PG1, PG2, and PG3 are
operated with seven rotation shafts TM1 to TM7.
[0040] The seven rotation shafts TM1 to TM7 will be described in
further detail.
[0041] The first rotation shaft TM1 connects the first sun gear S1
to the third sun gear S3 and is selectively connected to the input
shaft IS.
[0042] The second rotation shaft TM2 connects the first planet
carrier PC1 to the third ring gear R3 and is selectively connected
to the transmission housing H.
[0043] The third rotation shaft TM3 is connected to the first ring
gear R1.
[0044] The fourth rotation shaft TM4 is connected to the second sun
gear S2 and is directly connected to the transmission housing H so
as to be continuously operated as a fixed element
[0045] The fifth rotation shaft TM5 is connected to the second
planet carrier PC2 and is selectively connected respectively to the
input shaft IS and the third rotation shaft TM3.
[0046] The sixth rotation shaft TM6 is connected to the second ring
gear R2 and is selectively connected respectively to the second
rotation shaft TM2 and the third rotation shaft TM3.
[0047] The seventh rotation shaft TM7 is connected to the third
planet carrier PC3 and is directly connected to the output shaft OS
so as to be continuously operated as an output element.
[0048] In addition, five clutches C1, C2, C3, C4, and C5 being
control elements are disposed at connection portions between any
two rotation shafts among the rotation shafts TM1 to TM7 or between
the input shaft IS and any one rotation shaft among the rotation
shafts TM1 to TM7.
[0049] In addition, one brake B1 being control elements is disposed
at a connection portion between any one rotation shaft among the
rotation shaft TM1 to TM7 and the transmission housing H.
[0050] The six control elements C1 to C5 and B1 will be described
in further detail.
[0051] The first clutch C1 is disposed between the input shaft IS
and the first rotation shaft TM1 and selectively causes the input
shaft IS and the first rotation shaft TM1 to integrally rotate with
each other.
[0052] The second clutch C2 is disposed between the input shaft IS
and the fifth rotation shaft TM5 and selectively causes the input
shaft IS and the fifth rotation shaft TM5 to integrally rotate with
each other.
[0053] The third clutch C3 is disposed between the second rotation
shaft TM2 and the sixth rotation shaft TM6 and selectively causes
the second rotation shaft TM2 and the sixth rotation shaft TM6 to
integrally rotate with each other.
[0054] The fourth clutch C4 is disposed between the third rotation
shaft TM3 and the fifth rotation shaft TM5 and selectively causes
the third rotation shaft TM3 and the fifth rotation shaft TM5 to
integrally rotate with each other.
[0055] The fifth clutch C5 is disposed between the third rotation
shaft TM3 and the sixth rotation shaft TM6 and selectively causes
the third rotation shaft TM3 and the sixth rotation shaft TM6 to
integrally rotate with each other.
[0056] The first brake B1 is disposed between the second rotation
shaft TM2 and the transmission housing H and causes the second
rotation shaft TM2 to be operated as a selective fixed element.
[0057] The control elements including the first, second, third,
fourth, and fifth clutches C1, C2, C3, C4, and C5 and the first
brake B1 may be multi-plates friction elements of wet type that are
operated by hydraulic pressure.
[0058] FIG. 2 is an operation chart of control elements at each
speed stage in the planetary gear train according to various
embodiments of the present invention.
[0059] As shown in FIG. 2, three control elements are operated at
each speed stage in the planetary gear train according to various
embodiments of the present invention.
[0060] The first and fourth clutches C1 and C4 and the first brake
B1 are operated at a first forward speed stage D1. The input shaft
IS is connected to the first rotation shaft TM1 by operation of the
first clutch C1 and the third rotation shaft TM3 is connected to
the fifth rotation shaft TM3 by operation of the fourth clutch C4.
In a state that the torque of the input shaft IS is input to the
first rotation shaft TM1, the fourth rotation shaft TM4 is operated
as the fixed element and the second rotation shaft TM2 is operated
as the fixed element by operation of the first brake B1. Therefore,
the torque of the input shaft IS is shifted into the first forward
speed stage, and the first forward speed stage is output to the
output shaft OS through the seventh rotation shaft TM7.
[0061] The first, fourth, and fifth clutches C1, C4, and C5 are
operated at a second forward speed stage D2. The input shaft IS is
connected to the first rotation shaft TM1 by operation of the first
clutch C1, the third rotation shaft TM3 is connected to the fifth
rotation shaft TM3 by operation of the fourth clutch C4, and the
third rotation shaft TM3 is connected to the sixth rotation shaft
TM6 by operation of the fifth clutch C5. In a state that the torque
of the input shaft IS is input to the first rotation shaft TM1, the
fourth rotation shaft TM4 is operated as the fixed element.
Therefore, the torque of the input shaft IS is shifted into the
second forward speed stage, and the second forward speed stage is
output to the output shaft OS through the seventh rotation shaft
TM7.
[0062] The first, third, and fourth clutches C1, C3, and C4 are
operated at a third forward speed stage D3. The input shaft IS is
connected to the first rotation shaft TM1 by operation of the first
clutch C1, the second rotation shaft TM2 is connected to the sixth
rotation shaft TM6 by operation of the third clutch C3, and the
third rotation shaft TM3 is connected to the fifth rotation shaft
TM3 by operation of the fourth clutch C4. In a state that the
torque of the input shaft IS is input to the first rotation shaft
TM1, the fourth rotation shaft TM4 is operated as the fixed
element. Therefore, the torque of the input shaft IS is shifted
into the third forward speed stage, and the third forward speed
stage is output to the output shaft OS through the seventh rotation
shaft TM7.
[0063] The first, second, and fourth clutches C1, C2, and C4 are
operated at a fourth forward speed stage D4. The input shaft IS is
connected to the first rotation shaft TM1 by operation of the first
clutch C1, the input shaft IS is connected to the fifth rotation
shaft TM5 by operation of the second clutch C2, and the third
rotation shaft TM3 is connected to the fifth rotation shaft TM3 by
operation of the fourth clutch C4. In a state that the torque of
the input shaft IS is input to the first rotation shaft TM1 and the
fifth rotation shaft TM5, the fourth rotation shaft TM4 is operated
as the fixed element. Therefore, the torque of the input shaft IS
is shifted into the fourth forward speed stage, and the fourth
forward speed stage is output to the output shaft OS through the
seventh rotation shaft TM7.
[0064] The first, second, and fifth clutches C1, C2, and C5 are
operated at a fifth forward speed stage D5. The input shaft IS is
connected to the first rotation shaft TM1 by operation of the first
clutch C1, the input shaft IS is connected to the fifth rotation
shaft TM5 by operation of the second clutch C2, and the third
rotation shaft TM3 is connected to the sixth rotation shaft TM6 by
operation of the fifth clutch C5. In a state that the torque of the
input shaft IS is input to the first rotation shaft TM1 and the
fifth rotation shaft TM5, the fourth rotation shaft TM4 is operated
as the fixed element. Therefore, the torque of the input shaft IS
is shifted into the fifth forward speed stage, and the fifth
forward speed stage is output to the output shaft OS through the
seventh rotation shaft TM7.
[0065] The first, second, and third clutches C1, C2, and C3 are
operated at a sixth forward speed stage D6. The input shaft IS is
connected to the first rotation shaft TM1 by operation of the first
clutch C1, the input shaft IS is connected to the fifth rotation
shaft TM5 by operation of the second clutch C2, and the second
rotation shaft TM2 is connected to the sixth rotation shaft TM6 by
operation of the third clutch C3. In a state that the torque of the
input shaft IS is input to the first rotation shaft TM1 and the
fifth rotation shaft TM5, the fourth rotation shaft TM4 is operated
as the fixed element. Therefore, the torque of the input shaft IS
is shifted into the sixth forward speed stage, and the sixth
forward speed stage is output to the output shaft OS through the
seventh rotation shaft TM7.
[0066] The second, third, and fifth clutches C2, C3, and C5 are
operated at a seventh forward speed stage D7. The input shaft IS is
connected to the fifth rotation shaft TM5 by operation of the
second clutch C2, the second rotation shaft TM2 is connected to the
sixth rotation shaft TM6 by operation of the third clutch C3, and
the third rotation shaft TM3 is connected to the sixth rotation
shaft TM6 by operation of the fifth clutch C5. In a state that the
torque of the input shaft IS is input to the fifth rotation shaft
TM5, the fourth rotation shaft TM4 is operated as the fixed
element. Therefore, the torque of the input shaft IS is shifted
into the seventh forward speed stage, and the seventh forward speed
stage is output to the output shaft OS through the seventh rotation
shaft TM7.
[0067] The second, third, and fourth clutches C2, C3, and C4 are
operated at an eighth forward speed stage D8. The input shaft IS is
connected to the fifth rotation shaft TM5 by operation of the
second clutch C2, the second rotation shaft TM2 is connected to the
sixth rotation shaft TM6 by operation of the third clutch C3, and
the third rotation shaft TM3 is connected to the fifth rotation
shaft TM5 by operation of the fourth clutch C4. In a state that the
torque of the input shaft IS is input to the fifth rotation shaft
TM5, the fourth rotation shaft TM4 is operated as the fixed
element. Therefore, the torque of the input shaft IS is shifted
into the eighth forward speed stage, and the eighth forward speed
stage is output to the output shaft OS through the seventh rotation
shaft TM7.
[0068] The second and fourth clutches C2 and C4 and the first brake
B1 are operated at a reverse speed stage REV. The input shaft IS is
connected to the fifth rotation shaft TM5 by operation of the
second clutch C2 and the third rotation shaft TM3 is connected to
the fifth rotation shaft TM3 by operation of the fourth clutch C4.
In a state that the torque of the input shaft IS is input to the
first rotation shaft TM1, the fourth rotation shaft TM4 is operated
as the fixed element and the second rotation shaft TM2 is operated
as the fixed element by operation of the first brake B1. Therefore,
the torque of the input shaft IS is shifted into the reverse speed
stage, and the reverse speed stage is output to the output shaft OS
through the seventh rotation shaft TM7.
[0069] The planetary gear train according to various embodiments of
the present invention may achieve eight forward speed stages and
one reverse speed stage by control of three planetary gear sets
PG1, PG2, and PG3, five clutches C1, C2, C3, C4, and C5, and one
brake B1.
[0070] Since eight forward speed stages are achieved by using three
planetary gear sets PG1, PG2, and PG3, an internal structure of the
automatic transmission may be simplified and durability may be
improved.
[0071] Since fuel economy is improved due to achievement of
multiple speed stages and operation point at low RPM regions is
used, silent driving of the vehicle may be improved.
[0072] 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.
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