U.S. patent application number 16/842520 was filed with the patent office on 2021-06-17 for power transmission apparatus of hybrid electric vehicle.
This patent application is currently assigned to Hyundai Motor Company. The applicant listed for this patent is Hyundai Motor Company, Kia Motors Corporation. Invention is credited to Bong Hyun Cho, Byung Dae Choi, Gwang Soo Hwang, Jae Young Jeon, Jun Seong Kang, Hyung-Min Kim, Jin Yong Kim, Hyu Tae SHIM.
Application Number | 20210178887 16/842520 |
Document ID | / |
Family ID | 1000005623287 |
Filed Date | 2021-06-17 |
United States Patent
Application |
20210178887 |
Kind Code |
A1 |
SHIM; Hyu Tae ; et
al. |
June 17, 2021 |
POWER TRANSMISSION APPARATUS OF HYBRID ELECTRIC VEHICLE
Abstract
A power transmission apparatus for a hybrid electric vehicle may
include an input shaft receiving an engine torque, first and second
planetary gear sets respectively having first to third rotation
elements fourth to sixth rotation elements, a first shaft fixedly
connected to the first rotation element and the motor-generator and
selectively connectable to the input shaft, a second shaft fixedly
connected to the second and sixth rotation elements and selectively
connectable to the input shaft, a third shaft fixedly connected to
the third rotation element and selectively connectable to the
transmission housing, a fourth shaft fixedly connected to the
fourth rotation element and selectively connectable to the
transmission housing, a fifth shaft fixedly connecting the fifth
rotation element and an output gear and selectively connectable to
the third shaft, and a plurality of engagement elements including
at least one clutch and at least one brake.
Inventors: |
SHIM; Hyu Tae; (Hwaseong-Si,
KR) ; Cho; Bong Hyun; (Gunpo-Si, KR) ; Jeon;
Jae Young; (Osan-Si, KR) ; Choi; Byung Dae;
(Seoul, KR) ; Kim; Hyung-Min; (Suwon-Si, KR)
; Kim; Jin Yong; (Incheon, KR) ; Hwang; Gwang
Soo; (Hwaseong-Si, KR) ; Kang; Jun Seong;
(Gwacheon-Si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company
Kia Motors Corporation |
Seoul
Seoul |
|
KR
KR |
|
|
Assignee: |
Hyundai Motor Company
Seoul
KR
Kia Motors Corporation
Seoul
KR
|
Family ID: |
1000005623287 |
Appl. No.: |
16/842520 |
Filed: |
April 7, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16H 2200/0065 20130101;
F16H 3/724 20130101; B60K 6/442 20130101; F16H 2200/2007 20130101;
F16H 2200/2043 20130101; F16H 2200/2082 20130101; B60K 6/365
20130101; B60K 6/547 20130101 |
International
Class: |
B60K 6/365 20060101
B60K006/365; F16H 3/72 20060101 F16H003/72; B60K 6/547 20060101
B60K006/547 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 11, 2019 |
KR |
10-2019-0164615 |
Claims
1. A power transmission apparatus of a vehicle having power sources
of an engine and a motor-generator, the power transmission
apparatus comprising: an input shaft receiving a torque of the
engine; a first planetary gear set having a first rotation element,
a second rotation element, and a third rotation element and mounted
on the input shaft; a second planetary gear set having a fourth
rotation element, a fifth rotation element, and a sixth rotation
element and mounted on the input shaft; a first shaft fixedly
connected to the first rotation element and the motor-generator and
selectively connectable to the input shaft by a first engagement
element among a plurality of engagement elements; a second shaft
fixedly connected to the second rotation element and the sixth
rotation element and selectively connectable to the input shaft by
a second engagement element among the plurality of engagement
elements; a third shaft fixedly connected to the third rotation
element and selectively connectable to a transmission housing by a
third engagement element among the plurality of engagement
elements; a fourth shaft fixedly connected to the fourth rotation
element and selectively connectable to the transmission housing by
a fourth engagement element among the plurality of engagement
elements; and a fifth shaft fixedly connecting the fifth rotation
element and an output gear and selectively connectable to the third
shaft by a fifth engagement element among the plurality of
engagement elements, wherein the plurality of engagement elements
includes at least one clutch and at least one brake, as the first
to fifth engagement elements.
2. The power transmission apparatus of claim 1, wherein the first
planetary gear set is formed as a single pinion planetary gear set
having 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; wherein the second planetary
gear set is formed as a single pinion planetary gear set having 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.
3. The power transmission apparatus of claim 2, wherein the at
least one clutch of the plurality of engagement elements include: a
first clutch, as the first engagement element, mounted between the
first shaft and the input shaft; a second clutch, as the fifth
engagement element, mounted between the third shaft and the fifth
shaft; and a third clutch, as the second engagement element,
mounted between the second shaft and the input shaft, and wherein
the at least one brake of the plurality of engagement elements
include: a first brake, as the fourth engagement element, mounted
between the fourth shaft and the transmission housing; and a second
brake, as the third engagement element, mounted between the third
shaft and the transmission housing.
4. The power transmission apparatus of claim 3, wherein the first
brake is mounted between the second planetary gear set and the
motor-generator, wherein the second brake is mounted outside of the
first planetary gear set.
5. The power transmission apparatus of claim 4, further including a
one-way clutch mounted between the input shaft and an engine output
shaft.
6. The power transmission apparatus of claim 3, wherein the first
brake and the second brake are mounted between the second planetary
gear set and the motor-generator.
7. The power transmission apparatus of claim 6, further including a
one-way clutch mounted between the input shaft and an engine output
shaft.
8. The power transmission apparatus of claim 1, wherein the first
planetary gear set is formed as a double pinion planetary gear set
having a first sun gear as the first rotation element, a first ring
gear as the second rotation element, and a first planet carrier as
the third rotation element; wherein the second planetary gear set
is formed as a single pinion planetary gear set having 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.
9. The power transmission apparatus of claim 8, wherein the at
least one clutch of the plurality of engagement elements include: a
first clutch, as the first engagement element, mounted between the
first shaft and the input shaft; a second clutch, as the fifth
engagement element, mounted between the third shaft and the fifth
shaft; and a third clutch, as the second engagement element,
mounted between the second shaft and the input shaft; wherein the
at least one brake of the plurality of engagement elements include:
a first brake, as the fourth engagement element, mounted between
the fourth shaft and the transmission housing; and a second brake,
as the third engagement element, mounted between the third shaft
and the transmission housing.
10. The power transmission apparatus of claim 9, wherein the first
brake and the second brake are mounted between the second planetary
gear set and the motor-generator.
11. The power transmission apparatus of claim 10, further including
a one-way clutch mounted between the input shaft and an engine
output shaft.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to Korean Patent
Application No. 10-2019-0164615 filed on Dec. 11, 2019, the entire
contents of which is incorporated herein for all purposes by this
reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a power transmission
apparatus of a hybrid electric vehicle.
Description of Related Art
[0003] An environment-friendly technology of a vehicle is a core
technology which controls survival of a future vehicle industry,
and advanced vehicle makers have focused their energy on the
development of an environment-friendly vehicle to achieve
environmental and fuel efficiency regulations.
[0004] Therefore, vehicle makers have developed an electric vehicle
(EV), a hybrid electric vehicle (HEV), a fuel cell electric vehicle
(FCEV), and the like, as future vehicle technologies.
[0005] Since the future vehicle has various technological
restrictions such as a weight and cost, the vehicle makers have
paid attention to the hybrid electric vehicle as an alternative of
a realistic problem for meeting exhaust gas regulations and
improving fuel efficiency performance and have entered into keen
competition for commercializing the hybrid electric vehicle.
[0006] The hybrid electric vehicle is a vehicle using two or more
power sources. Two or more power sources may be combined by various
schemes and a gasoline engine or a diesel engine using the
conventional fossil fuel and a motor-generator driven by electrical
energy are mixed and used as the power sources.
[0007] In the hybrid electric vehicle, an EV mode in which the
hybrid electric vehicle is driven by only the motor, an HEV mode
using both the engine and the motor, and an ENG mode using only the
engine may be implemented according to the combination of the
engine and the motor. Furthermore, the hybrid electric vehicle can
provide a significant improvement of fuel efficiency through an
idle stop function of stopping the engine when the vehicle stops,
and also through a regenerative braking, where a motor-generator is
driven as a generator to generate electricity by a kinetic energy
of the vehicle under a braking situation, such generated
electricity is stored in a battery, and the stored electricity is
reused in driving the vehicle.
[0008] A transmission for hybrid electric vehicle performs shifting
operation based on torques of the engine and the motor-generator.
Such a transmission may realize multi-speed, e.g., six speeds, of
various modes by additionally employing an engine clutch to be
variably connected to the engine to a traditional multi-speed,
e.g., six-speed, automatic transmission.
[0009] Such a transmission for a hybrid electric vehicle may
typically include three planetary gear sets, six operational
elements, and at least one one-way clutch OWC, similarly to a
conventional six-speed automatic transmission, as well as the
additional engine clutch. By such a scheme, the transmission for a
hybrid electric vehicle may not be understood to be best optimized
for a hybrid electric vehicle, and may be improved to provide
better efficiency, better performance, and better fuel consumption,
or less production cost.
[0010] The information included in this Background of the Invention
section is only for enhancement of understanding of the general
background of the invention and may 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 power transmission apparatus of a hybrid electric
vehicle having advantages of, while simplifying the structure of a
transmission, realizing various shifting modes, such as an engine
mode and a parallel hybrid mode respectively having multiple
speeds, an electronically-controlled continuously variable shifting
mode (eCVT mode), and an electric vehicle mode (EV mode), reducing
a production cost, and realizing fuel consumption characteristic
and power performance above an equivalent transmission.
[0012] An exemplary power transmission apparatus is for a hybrid
electric vehicle having power sources of an engine and a
motor-generator, and includes, an input shaft receiving a torque of
the engine, a first planetary gear set having first, second, and
third rotation elements and mounted on the input shaft, a second
planetary gear set having fourth, fifth, and sixth rotation
elements and mounted on the input shaft, a first shaft fixedly
connected to the first rotation element and the motor-generator and
selectively connectable to the input shaft, a second shaft fixedly
connected to the second rotation element and the sixth rotation
element and selectively connectable to the input shaft, a third
shaft fixedly connected to the third rotation element and
selectively connectable to the transmission housing, a fourth shaft
fixedly connected to the fourth rotation element and selectively
connectable to the transmission housing, a fifth shaft fixedly
connecting the fifth rotation element and an output gear and
selectively connectable to the third shaft, and a plurality of
engagement elements including at least one clutch and at least one
brake.
[0013] The first planetary gear set may be formed as a single
pinion planetary gear set having 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 formed as a single pinion
planetary gear set having 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.
[0014] The plurality of engagement elements may include a first
clutch mounted between the first shaft and the input shaft, a
second clutch mounted between the third shaft and the fifth shaft,
a third clutch mounted between the second shaft and the input
shaft, a first brake mounted between the fourth shaft and the
transmission housing, and a second brake mounted between the third
shaft and the transmission housing.
[0015] The first brake may be mounted between the second planetary
gear set and the motor-generator. The second brake may be mounted
radially external to the first planetary gear set.
[0016] The first brake and the second brake may be mounted between
the second planetary gear set and the motor-generator.
[0017] The first planetary gear set may be formed as a double
pinion planetary gear set having a first sun gear as the first
rotation element, a first ring gear as the second rotation element,
and a first planet carrier as the third rotation element. The
second planetary gear set may be formed as a single pinion
planetary gear set having 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.
[0018] The plurality of engagement elements may include a first
clutch mounted between the first shaft and the input shaft, a
second clutch mounted between the third shaft and the fifth shaft,
a third clutch mounted between the second shaft and the input
shaft, a first brake mounted between the fourth shaft and the
transmission housing, and a second brake mounted between the third
shaft and the transmission housing.
[0019] Furthermore, a one-way clutch may be mounted between the
input shaft and the engine output shaft.
[0020] According to a power transmission apparatus of a hybrid
electric vehicle according to an exemplary embodiment of the
present invention, while simplifying the structure of a
transmission by employing only two planetary gear sets, various
shifting modes, such as an engine mode and a parallel hybrid mode
respectively having four shifting stages, an
electronically-controlled continuously variable shifting mode (eCVT
mode), and an electric vehicle mode (EV mode) having four shifting
stages, may be realized, reducing a production cost, and realizing
fuel consumption characteristic and power performance above an
equivalent transmission.
[0021] Furthermore, the number of employed planetary gear sets may
be decreased in comparison to a conventional six-speed
transmission, and therefore, an overall length may be decreased,
improving installability into a vehicle.
[0022] Furthermore, a one-way clutch is mounted between the input
shaft and the engine output shaft, and thereby, an engine drag may
be prevented in the EV mode and in regenerative braking.
[0023] Furthermore, effects which may 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.
[0024] 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
[0025] FIG. 1 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0026] FIG. 2 is an operation chart of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments.
[0027] FIG. 3 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0028] FIG. 4 is an operation chart of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments.
[0029] FIG. 5 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0030] FIG. 6 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0031] FIG. 7 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0032] FIG. 8 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0033] It may 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 present invention. The specific design features
of the present invention as included herein, including, for
example, specific dimensions, orientations, locations, and shapes
will be determined in part by the particularly intended application
and use environment.
[0034] In the figures, reference numbers refer to the same or
equivalent portions of the present invention throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0035] 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 present
invention(s) will be described in conjunction with exemplary
embodiments of the present invention, it will be understood that
the present description is not intended to limit the present
invention(s) to those exemplary embodiments. On the other hand, the
present invention(s) is/are intended to cover not only the
exemplary embodiments of the present invention, but also various
alternatives, modifications, equivalents and other embodiments,
which may be included within the spirit and scope of the present
invention as defined by the appended claims.
[0036] Exemplary embodiments of the present application will be
described more fully hereinafter with reference to the accompanying
drawings, in which exemplary embodiments of the present invention
are shown. As those skilled in the art would realize, the described
embodiments may be modified in various different ways, all without
departing from the spirit or scope of the present invention.
[0037] The drawings and description are to be regarded as
illustrative in nature and not restrictive, and like reference
numerals designate like elements throughout the specification.
[0038] 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.
[0039] FIG. 1 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0040] Referring to FIG. 1, a power transmission apparatus of a
hybrid electric vehicle according to various exemplary embodiments
receives torques from power sources of an engine ENG and a
motor-generator MG and includes an input shaft IS, first and second
planetary gear sets PG1 and PG2, five shafts TM1 to TM5
respectively connecting rotation elements of the first planetary
gear set and the second planetary gear set PG1 and PG2, and
engagement elements of three clutches C1 to C3 and two brakes B1
and B2.
[0041] As a result, the torques input from the engine ENG and the
motor-generator MG is shifted by a cooperative operation of the
first planetary gear set and the second planetary gear set PG1 and
PG2, and a shifted torque is output through an output gear OG.
[0042] The engine ENG is a primary power source, and may be
implemented as one of various types such as a gasoline engine or a
diesel engine.
[0043] The motor-generator MG is fixedly connected to the planetary
gear set portion PG and is used as an auxiliary power source.
[0044] The motor-generator MG may act as a motor and also as a
generator, and includes a stator ST and a rotor RT, where the
stator ST is fixed to a transmission housing H, and the rotor RT is
internally mounted within the stator ST and rotatable relative to
the stator ST.
[0045] The input shaft IS is an input member, and may receive the
torque of the engine ENG through an engine output shaft.
[0046] The output gear OG is an output element, and may deliver a
shifted torque to a driveshaft through a differential
apparatus.
[0047] The first planetary gear set PG1 is a single pinion
planetary gear set, and may include a first rotation element N1 of
a first sun gear S1, a second rotation element N2 of a first planet
carrier PC1 rotatably supporting a plurality of first pinion gears
P1 externally gear-meshed with the first sun gear S1, and a third
rotation element N3 of a first ring gear R1 internally gear-meshed
with the plurality of first pinion gears P1.
[0048] The second planetary gear set PG2 is a single pinion
planetary gear set, and includes a fourth rotation element N4 of a
second sun gear S2, a fifth rotation element N5 of a second planet
carrier PC2 rotatably supporting a plurality of second pinion gears
P2 externally gear-meshed with the second sun gear S2, and a sixth
rotation element N6 of a second ring gear R2 internally gear-meshed
with the plurality of second pinion gears P2.
[0049] That is, a power transmission apparatus of a hybrid electric
vehicle according to various exemplary embodiments is formed by a
combination of first and second planetary gear sets PG1 and PG2,
and includes five shafts TM1, TM2, TM3, TM4, and TM5.
[0050] The first to sixth rotation elements N1 to N6 are fixedly
connected to a corresponding one of the shafts TM1 to TM5, and the
first planetary gear set and the second planetary gear set PG1 and
PG2 are operated by a plurality of engagement elements including at
least one clutch and at least one brake.
[0051] The five shafts TM1 to TM5 are hereinafter described in
detail.
[0052] The first shaft TM1 is fixedly connected to the first
rotation element N1 (first sun gear S1) and the motor-generator MG,
and while acting as an input element of the motor-generator MG, is
selectively connectable to the input shaft IS, selectively acting
as an input element of the engine ENG
[0053] The second shaft TM2 fixedly connects the second rotation
element N2 (first planet carrier PC1) and the sixth rotation
element N6 (second ring gear R2), and is selectively connectable to
the input shaft IS, selectively acting as an input element.
[0054] The third shaft TM3 is fixedly connected to the third
rotation element N3 (first ring gear R1), and selectively
connectable to the transmission housing H, selectively acting as a
fixed element.
[0055] The fourth shaft TM4 is fixedly connected to the fourth
rotation element N4 (second sun gear S2), and selectively
connectable to the transmission housing H, selectively acting as a
fixed element.
[0056] The fifth shaft TM5 is fixedly connected to the fifth
rotation element N5 (second planet carrier PC2), selectively
connectable to the third shaft TM3, and fixedly connected to the
output gear OG, always acting as an output element.
[0057] In an exemplary embodiment of the present invention, when
two or more members are described to be "fixedly connected", where
each of the members may be any of a shaft, an input shaft, an
output shaft, a rotation member, and a transmission housing, it
means that the fixedly connected members always rotate at a same
speed.
[0058] When two or more members are described to be "selectively
connectable" by an engagement element, it means that the
selectively connectable members rotate separately when the
engagement element is not engaged, and rotates at a same speed when
the engagement element is engaged.
[0059] It may be understood that in the case that a member is
"selectively connectable" to a transmission housing by an
engagement element, the member may be stationary when the
engagement element is engaged.
[0060] Engagement elements of first, second, and third clutches C1,
C2, and C3 are mounted between a corresponding pair of the five
shafts TM1 to TM5 and the input shaft, to form selective
connections
[0061] Engagement elements of first and second brakes B1 and B2 are
mounted between the transmission housing H and a corresponding
shaft of the five shafts TM1 to TM5, to form selective
connections
[0062] The five engagement elements of the three clutches C1, C2,
and C3 and the two brakes B1 and B2 are mounted as follows.
[0063] The first clutch C1 is mounted between the first shaft TM1
and the input shaft IS, and selectively connects the first shaft
TM1 and the input shaft IS, controlling power delivery
therebetween.
[0064] The second clutch C2 is mounted between the third shaft TM3
and the fifth shaft TM5, and selectively connects the second shaft
TM2 and the fifth shaft TM5, controlling power delivery
therebetween.
[0065] The third clutch C3 is mounted between the second shaft TM2
and the input shaft IS, and selectively connects the first shaft
TM1 and the input shaft IS, controlling power delivery
therebetween.
[0066] The first brake B1 is mounted between the fourth shaft TM4
and the transmission housing H, and selectively connects the fourth
shaft TM4 to the transmission housing H.
[0067] The second brake B2 is mounted between the third shaft TM3
and the transmission housing H, and selectively connects the third
shaft TM3 to the transmission housing H.
[0068] The first brake B1 is mounted between the second planetary
gear set PG2 and the motor-generator MG, and the second brake B2 is
mounted radially external to the first planetary gear set PG1.
[0069] The engagement elements of the first, second, and third
clutches C1, C2, and C3 and the first brake and the second brake B1
and B2 may be realized as multi-plate hydraulic pressure friction
devices that are frictionally engaged by hydraulic pressure,
however, it may not be understood to be limited thereto, since
various other configuration that are electrically controllable may
be available.
[0070] FIG. 2 is an operation chart of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of FIG. 1.
[0071] Referring to FIG. 2, a power transmission apparatus of a
hybrid electric vehicle according to various exemplary embodiments
realizes an engine mode (hybrid mode) and an EV mode respectively
having four fixed shifting stages, and also realizes an eCVT mode
facilitating electronically-controlled continuously variable
shifting.
[0072] In the engine mode (hybrid mode), the engine ENG is
operated. In the instant state, the torque of the engine ENG is
input to the first planetary gear set PG1 by operation of at least
one of the first and third clutches C1 and C3, and the second
clutch C2 and the first brake and the second brake B1 and B2 are
controlled to realize four fixed shifting stages.
[0073] In the eCVT mode, the engine ENG is operated at a fixed
rotation speed, and the third clutch C3 is engaged to transmit the
torque of the engine ENG to the second shaft TM2. Simultaneously,
the motor-generator MG connected to the first shaft TM1 is operated
to deliver a motor torque to the first rotation element N1, and the
rotation speed of the motor-generator MG is varied to vary gear
ratio of the transmission to achieve gear ratios for a high gear
(gear ratio below 1.0).
[0074] In the EV mode, the first clutch C1 is released to
disconnect the first planetary gear set PG1 from the engine ENG and
simultaneously, the torque of the motor-generator MG is transmitted
to the first rotation element N1 through the first shaft TM1.
Similarly to the engine mode, the second and third clutches C2 and
C3 and the first brake and the second brake B1 and B2 are
controlled to realize four EV fixed shifting stages.
[0075] Here, the engine mode (hybrid mode) and the eCVT mode may be
combined to realize a shifting mode of at least five speeds.
[0076] That is, while maintaining the sift-stages of first forward
speed to fourth forward speed in the engine mode, an overdrive OD
may be realized by the eCVT mode performing
electronically-controlled continuously variable shifting to realize
a gear ratio appropriate for a high gear.
[0077] Hereinafter, an operation of a power transmission apparatus
of a hybrid electric vehicle according to various exemplary
embodiments is described in detail in connection with respective
modes.
[0078] [Engine Mode First Forward Speed (Hybrid Mode First Forward
Speed)]
[0079] In an engine mode first forward speed, the engine ENG is
operated, and the first clutch C1 and the first brake and the
second brake B1 and B2 are simultaneously operated.
[0080] Accordingly, the fourth shaft TM4 acts as a fixed element by
the operation of first brake B1, and the third shaft TM3 acts as a
fixed element by the operation of second brake B2. In the instant
state, by the operation of the first clutch C1, the torque of the
engine ENG is input to the first rotation element N1 through the
first shaft TM1.
[0081] As a result, a reduced speed output is delivered to the
fifth rotation element N5 of the first planetary gear set and the
second planetary gear set PG1 and PG2, and the torque of the engine
mode first forward speed is output through the output gear OG
connected to the fifth rotation element N5 through the fifth shaft
TM5.
[0082] Here, when the motor-generator MG is driven, the torque of
the motor-generator MG is added to the first shaft TM1, and
therefore, a hybrid mode first forward speed may be realized.
[0083] [Engine Mode Second Forward Speed (Hybrid Mode Second
Forward Speed)]
[0084] In an engine mode second forward speed, the engine ENG is
operated, and the first clutch and second clutch C1 and C2 and the
first brake B1 are simultaneously operated.
[0085] Accordingly, the fourth shaft TM4 acts as a fixed element by
the operation of first brake B1. In the instant state, the third
shaft TM3 and the fifth shaft TM5 are interconnected by the
operation of the second clutch C2, and by the operation of the
first clutch C1, the torque of the engine ENG is input to the first
rotation element N1 through the first shaft TM1.
[0086] As a result, a reduced speed output is delivered to the
fifth rotation element N5 of the first planetary gear set and the
second planetary gear set PG1 and PG2, and the torque of the engine
mode second forward speed is output through the output gear OG
connected to the fifth rotation element N5 through the fifth shaft
TM5.
[0087] Here, when the motor-generator MG is driven, the torque of
the motor-generator MG is added to the first shaft TM1, and
therefore, a hybrid mode second forward speed may be realized.
[0088] [Engine Mode Third Forward Speed (Hybrid Mode Third Forward
Speed)]
[0089] In an engine mode third forward speed, the engine ENG is
operated, and the first and the third clutch C1 and C3, first brake
B1 are simultaneously operated.
[0090] Accordingly, the fourth shaft TM4 acts as a fixed element by
the operation of first brake B1. In the instant state, by the
operation of the first and third clutches C1 and C3, the torque of
the engine ENG is input to the first rotation element N1 through
the first shaft TM1, and is input to the second and sixth rotation
elements N2 and N6 through the second shaft TM2.
[0091] As a result, a reduced speed output is delivered to the
fifth rotation element N5 of the first planetary gear set and the
second planetary gear set PG1 and PG2, and the torque of the engine
mode third forward speed is output through the output gear OG
connected to the fifth rotation element N5 through the fifth shaft
TM5.
[0092] Here, when the motor-generator MG is driven, the torque of
the motor-generator MG is added to the first shaft TM1, and
therefore, a hybrid mode third forward speed may be realized.
[0093] [Engine Mode Fourth Forward Speed (Hybrid Mode Fourth
Forward Speed)]
[0094] In an engine mode fourth forward speed, the engine ENG is
operated, and the first and the second and third clutches C1, C2,
and C3 are simultaneously operated.
[0095] Accordingly, the third shaft TM3 and the fifth shaft TM5 are
interconnected by the operation of the second clutch C2, and the
torque of the engine ENG is simultaneously input to the first shaft
TM1 and the second shaft TM2 by the operation of the first and
third clutches C1 and C3. Therefore, the first planetary gear set
and the second planetary gear set PG1 and PG2 integrally
rotates.
[0096] As a result, in the first planetary gear set and the second
planetary gear set PG1 and PG2, an input torque is directly output
(at a ratio of 1:1) through the output gear OG connected to the
fifth rotation element N5 through the fifth shaft TM5, outputting a
torque of engine mode fourth forward speed.
[0097] Here, when the motor-generator MG is driven, the torque of
the motor-generator MG is added to the first shaft TM1, and
therefore, a hybrid mode fourth forward speed may be realized.
[0098] In such an engine mode, while a vehicle is stopped with the
engine ENG running, the first clutch C1 may be operated to transmit
the torque of the engine ENG to the motor-generator MG to generate
electricity to recharge a battery.
[0099] [eCVT Mode]
[0100] In the eCVT mode, the engine ENG is operated at a fixed
rotation speed, and the second and third clutches C2 and C3 are
operated.
[0101] Accordingly, the third shaft TM3 and the fifth shaft TM5 are
interconnected by the operation of the second clutch C2, the third
clutch C3 is operated to transmit the torque of the engine ENG to
the second shaft TM2, and simultaneously, the torque of the
motor-generator MG connected to the first shaft TM1 is transmitted
to the first rotation element N1.
[0102] In such a state, an eCVT mode having gear ratios appropriate
for a high gear may be realized by varying the rotation speed of
the motor-generator MG.
[0103] [EV Mode First Speed]
[0104] In an EV mode first speed, the first clutch C1 is released
to disconnect the engine ENG In the instant state, the first brake
and the second brake B1 and B2 are simultaneous operated, and the
motor-generator MG is operated.
[0105] Accordingly, the fourth shaft TM4 and the third shaft TM3
act as fixed elements by the operation of the first brake and the
second brake B1 and B2. In the instant state, the torque of the
motor-generator MG is input to the first rotation element N1
through the first shaft TM1.
[0106] As a result, a reduced speed output is delivered to the
fifth rotation element N5 of the first planetary gear set and the
second planetary gear set PG1 and PG2, and the torque of the EV
mode first speed is output through the output gear OG connected to
the fifth rotation element N5 through the fifth shaft TM5.
[0107] [EV Mode Second Speed]
[0108] In an EV mode second speed, the first clutch C1 is released
to disconnect the engine ENG. In the instant state, the second
clutch C2 and the first brake B1 are simultaneous operated and the
motor-generator MG is operated.
[0109] Accordingly, the third shaft TM3 and the fifth shaft TM5 are
interconnected by the operation of the second clutch C2, and the
fourth shaft TM4 acts as a fixed element by the operation of first
brake B1. In the instant state, the torque of the motor-generator
MG is input to the first rotation element N1 through the first
shaft TM1.
[0110] As a result, a reduced speed output is delivered to the
fifth rotation element N5 of the first planetary gear set and the
second planetary gear set PG1 and PG2, and the torque of the EV
mode second speed is output through the output gear OG connected to
the fifth rotation element N5 through the fifth shaft TM5.
[0111] [EV Mode Third Speed]
[0112] In an EV mode third speed, the first clutch C1, the third
clutch C3, and the first brake B1 are simultaneous operated and the
motor-generator MG is operated.
[0113] Accordingly, the first shaft TM1 and the second shaft TM2
are interconnected by the operation of the first clutch C1 and the
third clutch C3, and the fourth shaft TM4 acts as a fixed element
by the operation of first brake B1. In the instant state, the
torque of the motor-generator MG is input to the first rotation
element N1 through the first shaft TM1 and to the second rotation
element N2 through the input shaft IS and the second shaft TM2.
[0114] As a result, the first planetary gear set PG1 integrally
rotates and a reduced speed is output at the fifth rotation element
N5 of the second planetary gear set PG2. Accordingly, the torque of
the EV mode third speed is output through the output gear OG
connected to the fifth rotation element N5 through the fifth shaft
TM5.
[0115] [EV Mode Fourth Speed]
[0116] In an EV mode fourth speed, the first, second, and third
clutches C1, C2, and C3 are simultaneous operated, and the
motor-generator MG is operated.
[0117] Accordingly, the first planetary gear set PG1 integrally
rotates by the operation of the first and third clutches C1 and C3,
and the second planetary gear set PG2 integrally rotates by the
operation of the second clutch C2, since the torque of the
motor-generator MG is simultaneously input to the fifth and sixth
rotation elements N5 and N6. Therefore, the first planetary gear
set and the second planetary gear set PG1 and PG2 integrally
rotates.
[0118] As a result, in the first planetary gear set and the second
planetary gear set PG1 and PG2, an input torque is directly output
(at a ratio of 1:1) through the output gear OG connected to the
fifth rotation element N5 through the fifth shaft TM5, outputting a
torque of EV mode fourth speed.
[0119] FIG. 3 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments. FIG. 4 is an operation chart of a power
transmission apparatus of a hybrid electric vehicle according to
various exemplary embodiments.
[0120] Referring to FIG. 3, a power transmission apparatus of a
hybrid electric vehicle according to various exemplary embodiments
in FIG. 3 differ from the various exemplary embodiments in FIG. 1
in that a one-way clutch OWC is applied between the input shaft IS
and the engine output shaft EOS.
[0121] Since the one-way clutch OWC is mounted between the input
shaft IS and the engine output shaft EOS, an engine drag may be
prevented in the EV mode and in regenerative braking.
[0122] As a result, a power transmission apparatus of a hybrid
electric vehicle according to various exemplary embodiments merely
differ from the various exemplary embodiments in the feature of
employing the one-way clutch, and other arrangement remains the
same, which is not further described in detail.
[0123] Furthermore, referring to FIG. 4, shifting modes may be
realized in the same way as in the various exemplary embodiments in
FIG. 1 except for only the operation of the one-way clutch OWC, and
therefore shifting operation is not further described in
detail.
[0124] FIG. 5 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0125] Referring to FIG. 5, a power transmission apparatus of a
hybrid electric vehicle according to various exemplary embodiments
differ from the various exemplary embodiments in FIG. 1 in the
locations of the first brake and the second brake B1 and B2.
[0126] That is, in the various exemplary embodiments of the present
invention in FIG. 1, the first brake B1 is located between the
second planetary gear set PG2 and the motor-generator MG and the
second brake B2 is located radially external to the first planetary
gear set PG1. However, in the various exemplary embodiments of the
present invention of FIG. 5, the first brake and the second brake
B1 and B2 are located between the second planetary gear set PG2 and
the motor-generator MG.
[0127] As a result, a power transmission apparatus of a hybrid
electric vehicle according to various exemplary embodiments of FIG.
5 merely differ from the various exemplary embodiments of FIG. 1 in
the locations of the first brake and the second brake B1 and B2,
and other arrangement remains the same, which is not further
described in detail.
[0128] Furthermore, shifting modes may be realized in the same way
as in the various exemplary embodiments of the present invention in
FIG. 1, and therefore shifting operation is not further described
in detail.
[0129] FIG. 6 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0130] Referring to FIG. 6, a power transmission apparatus of a
hybrid electric vehicle according to various exemplary embodiments
differ from the various exemplary embodiments in FIG. 5 in that a
one-way clutch OWC is applied between the input shaft IS and the
engine output shaft EOS.
[0131] Since the one-way clutch OWC is mounted between the input
shaft IS and the engine output shaft EOS, an engine drag may be
prevented in the EV mode and in regenerative braking.
[0132] As a result, a power transmission apparatus of a hybrid
electric vehicle according to various exemplary embodiments of FIG.
6 merely differ from the various exemplary embodiments in FIG. 5 in
the feature of employing the one-way clutch, and other arrangement
remains the same, which is not further described in detail.
[0133] Furthermore, shifting modes may be realized in the same way
as in the various exemplary embodiments of FIG. 3 except for only
the operation of the one-way clutch OWC, while others remain the
same, and therefore shifting operation is not further described in
detail.
[0134] FIG. 7 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0135] Referring to FIG. 7, a power transmission apparatus of a
hybrid electric vehicle according to various exemplary embodiments
differs from the various exemplary embodiments in FIG. 5 in an
arrangement of the first planetary gear set PG1.
[0136] That is, in the various exemplary embodiments of the present
invention in FIG. 5, the first planetary gear set PG1 is formed as
a single pinion planetary gear set. However, in the various
exemplary embodiments of the present invention in FIG. 7, the first
planetary gear set PG1 is formed as a double pinion planetary gear
set.
[0137] That is, the first planetary gear set PG1 of various
exemplary embodiments in FIG. 7 is a double pinion planetary gear
set, and includes a first rotation element N1 of a first sun gear
S1, a second rotation element N2 of a first ring gear R1 internally
gear-meshed with a plurality of first pinion gears P1 that are
externally gear-meshed with the first sun gear S1, and a third
rotation element N3 of a first planet carrier PC1 rotatably
supporting the plurality of first pinion gears P1.
[0138] As a result, a power transmission apparatus of a hybrid
electric vehicle according to various exemplary embodiments in FIG.
7 merely differ from the various exemplary embodiments in FIG. 5 in
employing a different type of the first planetary gear set PG1, and
other arrangement remains the same, which is not further described
in detail.
[0139] Furthermore, shifting modes may be realized in the same way
as in the various exemplary embodiments of the present invention in
FIG. 1, and therefore shifting operation is not further described
in detail.
[0140] FIG. 8 is a schematic diagram of a power transmission
apparatus of a hybrid electric vehicle according to various
exemplary embodiments of the present invention.
[0141] Referring to FIG. 8, a power transmission apparatus of a
hybrid electric vehicle according to various exemplary embodiments
differs from the various exemplary embodiments in FIG. 7 in that a
one-way clutch OWC is applied between the input shaft IS and the
engine output shaft EOS.
[0142] Since the one-way clutch OWC is mounted between the input
shaft IS and the engine output shaft EOS, an engine drag may be
prevented in the EV mode and in regenerative braking.
[0143] As a result, a power transmission apparatus of a hybrid
electric vehicle according to various exemplary embodiments in FIG.
8 merely differ from the various exemplary embodiments in FIG. 7 in
the feature of employing the one-way clutch, and other arrangement
remains the same, which is not further described in detail.
[0144] Furthermore, shifting modes may be realized in the same way
as in the various exemplary embodiments in FIG. 3 except for only
the operation of the one-way clutch OWC, and therefore shifting
operation is not further described in detail.
[0145] As described above, a power transmission apparatus of a
hybrid electric vehicle according to exemplary embodiments employs
only two planetary gear sets PG1 and PG2, simplifying the structure
of a transmission. Furthermore, an engine mode and a parallel
hybrid mode respectively having six speeds and an
electronically-controlled continuously variable shifting mode (eCVT
mode) may be combined to realize various shifting modes having more
than four speeds, reducing a production cost, and realizing fuel
consumption characteristic and power performance above an
equivalent transmission.
[0146] Furthermore, the number of employed planetary gear sets may
be decreased in comparison to a conventional six-speed
transmission, and therefore, an overall length may be decreased,
improving installability.
[0147] Furthermore, a one-way clutch OWC is applied between the
input shaft IS and the engine output shaft EOS, and thereby, an
engine drag may be prevented in the EV mode and in regenerative
braking.
[0148] For convenience in explanation and accurate definition in
the appended claims, the terms "upper", "lower", "inner", "outer",
"up", "down", "upwards", "downwards", "front", "rear", "back",
"inside", "outside", "inwardly", "outwardly", "internal",
"external", "inner", "outer", "forwards", and "backwards" are used
to describe features of the exemplary embodiments with reference to
the positions of such features as displayed in the figures. It will
be further understood that the term "connect" or its derivatives
refer both to direct and indirect connection.
[0149] 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 present 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 to explain certain principles of the
present invention and their practical application, to 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 present invention be defined by the Claims appended
hereto and their equivalents.
* * * * *