Power transmission device for hybrid electric vehicles

Abstract

The present invention relates to a power transmission device of a hybrid electric vehicle, which includes: an input shaft configured to receive engine torque; a motor shaft configured to receive torque of a motor / generator; a first planetary gear set having a first rotating element, a second rotating element and a third rotating element, and mounted on the input shaft; a second planetary gear set having a fourth rotating element, a fifth rotating element and a sixth rotating element, and mounted on the input shaft; a first shaft fixedly connected to the first rotating element and selectively connected to each of the input shaft and the motor shaft; a second shaft fixedly connected to the second rotating element and the fifth rotating element, and selectively connected to the input shaft, the motor shaft and a transmission housing, respectively; a third shaft fixedly connected to the third rotating element and the fourth rotating element, and selectively connected to the transmission housing; a fourth shaft and a plurality of engaging elements.

Description

Technical Field

[0001] The present invention relates to a power transmission device of a hybrid electric vehicle. Background Art

[0002] Environmentally friendly technology of vehicles is a core technology that controls the survival of the future vehicle industry, and advanced vehicle manufacturers have focused their efforts on developing environmentally friendly vehicles to meet regulatory requirements for the environment and fuel efficiency.

[0003] Therefore, vehicle manufacturers have developed electric vehicles (EVs), hybrid electric vehicles (HEVs), fuel cell electric vehicles (FCEVs), and the like as future vehicle technologies.

[0004] Since future vehicles have various technical limitations such as weight and cost, vehicle manufacturers have focused on hybrid electric vehicles as an alternative to practical issues in order to comply with regulations on emission gases and improve fuel efficiency performance, and vehicle manufacturers have entered into a fierce competition to commercialize hybrid electric vehicles.

[0005] A hybrid electric vehicle is a vehicle that uses two or more power sources. Two or more power sources can be combined in various ways, and a gasoline engine or diesel engine using traditional fossil fuels is mixed with an electric motor / generator driven by electric energy and used as a power source.

[0006] In hybrid electric vehicles, depending on the combination of the engine and the electric motor, it is possible to achieve: an EV mode in which the hybrid electric vehicle is driven only by the electric motor; an HEV mode in which both the engine and the electric motor are used; and an ENG mode in which only the engine is used. Furthermore, hybrid electric vehicles can significantly improve fuel efficiency through an idle stop function (which stops the engine when the vehicle is stopped) and through regenerative braking, in which the electric motor / generator is driven as a generator to generate electricity using the kinetic energy of the vehicle under braking. The generated electricity is then stored in a battery and reused when the vehicle is driven.

[0007] The transmission of a hybrid electric vehicle performs shifting operations based on the torque of the engine and the motor / generator. This transmission can achieve multiple speeds, such as six speeds, in various modes by additionally using an engine clutch to variably connect the engine and a conventional multi-speed (e.g., six-speed) automatic transmission.

[0008] Such a hybrid electric vehicle transmission, similar to a conventional six-speed automatic transmission, may generally include three planetary gear sets, six operating elements, and at least one one-way clutch (OWC), as well as an additional engine clutch. With such a solution, the hybrid electric vehicle transmission may be understood as not being optimized for a hybrid electric vehicle, and the hybrid electric vehicle transmission may be improved to provide higher efficiency, better performance, better fuel consumption, and / or lower production costs.

[0009] The information contained in this Background section of the present invention is only for enhancement of understanding of the general background of the invention and is not to be considered as an acknowledgement or any form of indication that this information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0010] Various aspects of the present invention are directed to providing a power transmission device for a hybrid electric vehicle, which has the following advantages: while simplifying the transmission structure, various shifting modes are provided, such as an engine mode with multiple speeds and a parallel hybrid mode with an electronically-controlled continuously variable shifting mode (eCVT mode), and an electric vehicle mode (EV mode), thereby reducing production costs and achieving fuel consumption characteristics and power performance higher than those of an equivalent transmission.

[0011] A power transmission device of an exemplary hybrid electric vehicle includes: an input shaft configured to receive engine torque; a motor shaft configured to receive torque from a motor / generator; a first planetary gear set having a first rotating element, a second rotating element, and a third rotating element, and mounted on the input shaft; a second planetary gear set having a fourth rotating element, a fifth rotating element, and a sixth rotating element, and mounted on the input shaft; a first shaft fixedly connected to the first rotating element and selectively connected to each of the input shaft and the motor shaft; a second shaft fixedly connected to the second rotating element and the fifth rotating element, and selectively connected to the input shaft, the motor shaft, and a transmission housing, respectively; a third shaft fixedly connected to the third rotating element and the fourth rotating element, and selectively connected to the transmission housing; a fourth shaft fixedly connected to the sixth rotating element and the output gear; and a plurality of engaging elements, including at least one clutch and at least one brake.

[0012] The first planetary gear set is formed as a single pinion planetary gear set, having a first sun gear as a first rotation element, a first planet carrier as a second rotation element, and a first ring gear as a third rotation element. The second planetary gear set is formed as a single pinion planetary gear set, having a second sun gear as a fourth rotation element, a second planet carrier as a fifth rotation element, and a second ring gear as a sixth rotation element.

[0013] The plurality of engaging elements may include: a first clutch mounted between the first shaft and the input shaft; a second clutch mounted between the second shaft and the input shaft; a first brake mounted between the second shaft and the transmission housing; a second brake mounted between the third shaft and the transmission housing; a first claw clutch mounted between the first shaft and the motor shaft; and a second claw clutch mounted between the second shaft and the motor shaft.

[0014] The first claw clutch includes: a clutch drum connected to the motor shaft, having an inner periphery rotatably supported by the transmission case, and having a first drum gear and a second drum gear formed on the inner and outer sides of the clutch drum, respectively; a first shaft gear formed on the first shaft; a first clutch piston mounted on the inside of the clutch drum, formed with a first guide gear engaged with the first drum gear, formed with a first clutch gear engaged with the first shaft gear to transmit the torque of the motor shaft to the first shaft, forming a hydraulic chamber with the clutch drum, and supported by an elastic member; and a first reaction piston mounted on the inside of the clutch drum, supported by a first retaining ring, and forming a hydraulic chamber with the first clutch piston.

[0015] The second dog clutch shares a clutch drum with the first dog clutch, and the second dog clutch includes: a second shaft gear formed on the second shaft; a second clutch piston mounted on the outside of the clutch drum, formed with a second guide gear engaged with the second drum gear, formed with a second clutch gear engaged with the second shaft gear to transmit the torque of the motor shaft to the second shaft, forming a hydraulic chamber with the clutch drum, and supported by an elastic member; and a second reaction piston mounted on the outside of the clutch drum, supported by a second retaining ring, and forming a hydraulic chamber with the second clutch piston.

[0016] The plurality of engaging elements may include: a first clutch installed between the first shaft and the input shaft; a second clutch installed between the second shaft and the input shaft; a third clutch installed between the first shaft and the motor shaft; a fourth clutch installed between the second shaft and the motor shaft; a first brake installed between the second shaft and the transmission housing; and a second brake installed between the third shaft and the transmission housing.

[0017] Another exemplary hybrid electric vehicle power transmission device includes: an input shaft configured to receive engine torque; a motor shaft configured to receive torque from a motor / generator; a compound planetary gear set formed as a combination of a first planetary gear set and a second planetary gear set, the first planetary gear set and the second planetary gear set sharing a common planetary carrier and a common ring gear, and having a first rotating element, a second rotating element, a third rotating element and a fourth rotating element; a first shaft fixedly connected to the first rotating element and selectively connected to each of the input shaft and the motor shaft; a second shaft connected to the second rotating element and selectively connected to the input shaft, the motor shaft and the transmission housing, respectively; a third shaft connected to the third rotating element and selectively connected to the transmission housing; a fourth shaft fixedly connected to the fourth rotating element and the output gear; and a plurality of engaging elements, including at least one clutch and at least one brake.

[0018] The compound planetary gear set is formed in a Ravilhoux type, in which the first planetary gear set is formed as a double pinion planetary gear set and the second planetary gear set is formed as a single pinion planetary gear set.

[0019] The plurality of engaging elements may include: a first clutch mounted between the first shaft and the input shaft; a second clutch mounted between the second shaft and the input shaft; a first brake mounted between the second shaft and the transmission housing; a second brake mounted between the third shaft and the transmission housing; and a claw clutch unit including: a first claw clutch mounted between the first shaft and the motor shaft; and a second claw clutch mounted between the second shaft and the motor shaft.

[0020] The plurality of engaging elements may include: a first clutch installed between the first shaft and the input shaft; a second clutch installed between the second shaft and the input shaft; a third clutch installed between the first shaft and the motor shaft; a fourth clutch installed between the second shaft and the motor shaft; a first brake installed between the second shaft and the transmission housing; and a second brake installed between the third shaft and the transmission housing.

[0021] According to the power transmission device of the hybrid electric vehicle according to the exemplary embodiment of the present invention, various shifting modes can be realized while simplifying the transmission structure by using only two planetary gear sets, such as a parallel hybrid mode with an engine mode having four gears and two electronically controlled continuously variable transmission shifting modes (eCVT modes), and an electric vehicle mode (EV mode) with four gears, thereby reducing production costs and achieving fuel consumption characteristics and power performance higher than those of an equivalent transmission.

[0022] In addition, the number of planetary gear sets employed can be reduced compared to a conventional six-speed transmission, and therefore the overall length can be reduced, thereby improving installability into a vehicle.

[0023] In addition, by adopting the dog clutch unit DC, an eCVT mode with a gear ratio suitable for low gear can be achieved, and when traveling in city mode, fuel consumption can be improved by using the eCVT mode.

[0024] In addition, the effects that can be obtained or expected from the exemplary embodiments of the present invention are directly or implicitly described in the following detailed description. That is, various effects expected from the exemplary embodiments of the present invention will be described in the following detailed description.

[0025] The method and apparatus of the present invention have other features and advantages which will be apparent from the accompanying drawings and accompanying drawings incorporated herein. Figure 1 These will become apparent from or be described in more detail in the following description which serves to illustrate some principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of a power transmission device of a hybrid electric vehicle according to various exemplary embodiments of the present invention;

[0027] Figure 2 is a schematic diagram of a two-way system (TWS) of a power transmission device applied to a hybrid electric vehicle according to various exemplary embodiments;

[0028] Figure 3 is a first operation chart of a power transmission device of a hybrid electric vehicle according to various exemplary embodiments;

[0029] Figure 4 is a second operation chart of the power transmission device of the hybrid electric vehicle according to various exemplary embodiments;

[0030] Figure 5 is a schematic diagram of a power transmission device of a hybrid electric vehicle according to various exemplary embodiments of the present invention;

[0031] Figure 6 is a schematic diagram of a power transmission device of a hybrid electric vehicle according to various exemplary embodiments of the present invention;

[0032] Figure 7 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 should be understood that the accompanying drawings are not necessarily drawn to scale, but rather present a somewhat simplified representation of various features illustrating the basic principles of the invention. The specific design features of the present invention contained herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the specific design application and use environment.

[0034] In the drawings, reference numbers refer to the same or equivalent parts 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, examples of which are shown in the accompanying drawings and described below. Although the present invention will be described in conjunction with exemplary embodiments of the present invention, it should be understood that this description is not intended to limit the present invention to those exemplary embodiments. On the other hand, the present invention is intended to cover not only the exemplary embodiments of the present invention, but also various alternatives, variations, equivalents and other embodiments that may be included within the spirit and scope of the present invention as defined by the appended claims.

[0036] Hereinafter, the exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings showing exemplary embodiments of the present invention. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways 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 refer to like elements throughout the specification.

[0038] In the following description, since the names of components are the same as each other and the order thereof is not particularly limited, the names of components are distinguished as first, second, etc. to distinguish the names.

[0039] Figure 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] Reference Figure 1 The power transmission device of the hybrid electric vehicle according to various exemplary embodiments receives torque from the power sources of the engine ENG and the motor / generator MG, and includes an input shaft IS, a motor shaft MS, and a planetary gear set portion PG, which is used to convert the torque of the engine ENG and the motor / generator MG received from the input shaft IS and the motor shaft MS into four fixed speed gears, and output the converted torque through the output gear OG.

[0041] The input shaft IS forms a central shaft of the transmission and always receives torque from the engine ENG.

[0042] The motor shaft MS is connected to the rotor hub of the motor / generator MG and always receives torque of the motor / generator MG.

[0043] The engine ENG is a main power source and may be implemented by one of various types such as a gasoline engine or a diesel engine.

[0044] The motor / generator MG is fixedly connected to the planetary gear set portion PG, and serves as an auxiliary power source.

[0045] The motor / generator MG can function as both a motor and a generator, and includes a stator ST fixed to the transmission case H and a rotor RT installed inside the stator ST and rotating relative to the stator ST.

[0046] The planetary gear set portion PG is formed by a combination of a first planetary gear set PG1 and a second planetary gear set PG2 , each of which is a single pinion planetary gear set.

[0047] The first planetary gear set PG1 includes a first sun gear S1 as a first rotation element N1 , a first planet carrier PC1 as a second rotation element N2 , and a first ring gear R1 as a third rotation element N3 , and first, second, and third shafts TM1 , TM2 , and TM3 are connected thereto.

[0048] The second planetary gear set PG2 includes a second sun gear S2 as a fourth rotation element N4 , a second planet carrier PC2 as a fifth rotation element N5 , and a second ring gear R2 as a sixth rotation element N6 , and second, third, and fourth shafts TM2 , TM3 , and TM4 are connected thereto.

[0049] That is, the planetary gear set portion PG is formed as a combination of a first planetary gear set PG1 and a second planetary gear set PG2 in which the first planet carrier PC1 and the second planet carrier PC2 are fixedly connected, and the first ring gear R1 and the second sun gear S2 are fixedly connected.

[0050] The first to sixth rotation elements N1 to N6 are fixedly connected to corresponding ones of the shafts TM1 to TM4 , and the first and second planetary gear sets PG1 and PG2 are operated by a plurality of engaging elements including at least one clutch and at least one brake.

[0051] The four axes TM1 to TM4 will be described in detail hereinafter.

[0052] The first shaft TM1 is fixedly connected to the first rotation element N1 (first sun gear S1 ), and is selectively connected to the input shaft IS and the motor shaft MS, thereby selectively serving as an input element.

[0053] The second shaft TM2 fixedly connects the second rotation element N2 (first planet carrier PC1) and the fifth rotation element N5 (second planet carrier PC2). The second shaft TM2 is selectively connected to the input shaft IS and the motor shaft MS, selectively serving as an input element, and selectively connected to the transmission case, selectively serving as a fixed element.

[0054] The third shaft TM3 fixedly connects the third rotation element N3 (the first ring gear R1 ) and the fourth rotation element N4 (the second sun gear S2 ), and is selectively connected to the transmission housing H, thereby selectively serving as a fixed element.

[0055] The fourth shaft TM4 is fixedly connected to the sixth rotation element N6 (the second ring gear R2 ), and is fixedly connected to the output gear OG, thereby always serving as an output element.

[0056] In an exemplary embodiment of the present invention, when two or more components are described as being “fixedly connected,” wherein each component may be any one of a shaft, an input shaft, an output shaft, a rotating component, and a transmission case, it means that the fixedly connected components always rotate at the same speed.

[0057] When two or more components are described as being "selectively connected" by a joining element, it means that when the joining element is not engaged, the selectively connected components rotate separately, and when the joining element is engaged, the selectively connected components rotate at the same speed.

[0058] It will be appreciated that where a member is “selectively connected” to the transmission housing via an engagement element, the member may be stationary when the engagement element is engaged.

[0059] A first clutch C1 and a second clutch C2 as engaging elements, and a dog clutch unit DC including a first dog clutch D1 and a second dog clutch D2 are installed between respective ones of the four shafts TM1 to TM4 and the input shaft to form selective connections.

[0060] A first brake B1 and a second brake B2 as engaging elements are installed between the transmission housing H and corresponding shafts among the four shafts TM1 to TM4 to form a selective connection.

[0061] Six engaging elements are installed as follows: two clutches C1 and C2 , two dog clutches D1 and D2 , and two brakes B1 and B2 .

[0062] The first clutch C1 is installed between the first shaft TM1 and the input shaft IS, and selectively connects the first shaft TM1 and the input shaft IS, thereby controlling power transmission between the first shaft TM1 and the input shaft IS.

[0063] The second clutch C2 is installed between the second shaft TM2 and the input shaft IS and selectively connects the second shaft TM2 and the input shaft IS, thereby controlling power transmission between the second shaft TM2 and the input shaft IS.

[0064] The first dog clutch D1 is installed between the first shaft TM1 and the motor shaft MS, and selectively connects the first shaft TM1 and the motor shaft MS, thereby controlling power transmission between the first shaft TM1 and the motor shaft MS.

[0065] The second dog clutch D2 is installed between the second shaft TM2 and the motor shaft MS, and selectively connects the second shaft TM2 and the motor shaft MS, thereby controlling power transmission between the second shaft TM2 and the motor shaft MS.

[0066] The first brake B1 is installed between the second shaft TM2 and the transmission housing H, and selectively connects the second shaft TM2 to the transmission housing H.

[0067] The second brake B2 is installed 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 and second clutches C1 and C2 and the first and second brakes B1 and B2 as engaging elements may be implemented as multi-plate hydraulic friction devices engaged by hydraulic friction, however, since various other configurations of electronic control may be used, it is understood that they are not limited thereto.

[0069] Figure 2 is a schematic diagram of a two-way system (TWS) of a power transmission apparatus applied to a hybrid electric vehicle according to various exemplary embodiments.

[0070] Reference Figure 2 , the dog clutch unit DC includes a two-way system (TWS) having a first dog clutch D1 and a second dog clutch D2.

[0071] That is, the dog clutch unit DC includes a clutch drum CD, a first shaft gear G1, a second shaft gear G2, first and second clutch pistons PS1, PS2, and first and second reaction pistons RP1, RP2 as first and second dog clutches D1, D2.

[0072] The first dog clutch D1 and the second dog clutch D2 share a clutch drum CD. The clutch drum CD is connected to the motor shaft MS, and the inner periphery of the clutch drum CD is rotatably supported by the transmission case H. A first drum gear DG1 and a second drum gear DG2 are formed on the radially inner and outer sides of the clutch drum CD, respectively.

[0073] In the first dog clutch D1 , a first shaft gear G1 is formed on an end portion of the first shaft TM1 , and in the second dog clutch D2 , a second shaft gear G2 is formed on an end portion of the second shaft TM2 .

[0074] The first clutch piston PS1 of the first dog clutch D1 is mounted inside the clutch drum CD and engages with the first drum gear DG1. A first guide gear GG1 is formed on the first clutch piston PS1 to guide its axial movement. A first clutch gear CG1 is formed on the first clutch piston PS1 to engage with the first shaft gear G1, transmitting torque from the motor shaft MS to the first shaft TM1.

[0075] The first clutch piston PS1 and the clutch drum CD form a hydraulic chamber, which is supplied with hydraulic pressure from a hydraulic line L in the transmission case H and the clutch drum CD.

[0076] The first clutch piston PS1 is supported by a return spring.

[0077] The second clutch piston PS2 of the second dog clutch D2 is mounted on the exterior of the clutch drum CD and engages with the second drum gear DG2. A second guide gear GG2 is formed on the second clutch piston PS2 to guide its axial movement. A second clutch gear CG2 is formed on the second clutch piston PS2 to engage with the second shaft gear G2, transmitting torque from the motor shaft MS to the second shaft TM2.

[0078] The second clutch piston PS2 and the clutch drum CD form a hydraulic chamber, which is supplied with hydraulic pressure from a hydraulic line L in the transmission housing H and the clutch drum CD. The second clutch piston PS2 is supported by a return spring.

[0079] The first reaction piston RP1 of the first dog clutch D1 is mounted inside the clutch drum CD and axially supported by the first snap ring SR1. The first reaction piston RP1 and the first clutch piston PS1 form a hydraulic chamber, which is supplied with hydraulic pressure from a hydraulic line L in the transmission case H and the clutch drum CD.

[0080] The second reaction piston RP2 of the second dog clutch D2 is mounted inside the clutch drum CD and is axially supported by the second snap ring SR2.

[0081] The second reaction piston RP2 and the second clutch piston PS2 form a hydraulic chamber, which is supplied with hydraulic pressure from a hydraulic line L in the transmission case H and the clutch drum CD.

[0082] Figure 3 is a first operational chart of a power transmitting apparatus of a hybrid electric vehicle according to various exemplary embodiments.

[0083] Reference Figure 3 According to various exemplary embodiments, the power transmission device of the hybrid electric vehicle realizes an engine mode (hybrid mode) and an EV mode each having four fixed gears, and also realizes an eCVT1 mode and an eCVT2 mode each performing electronically controlled continuously variable transmission.

[0084] In engine mode (hybrid mode), engine ENG is running. In a transient state, the torque of engine ENG is input to planetary gear set portion PG by operating at least one of the first clutch C1 and the second clutch C2, and the first brake B1 and the second brake B2 are controlled to achieve four fixed gears.

[0085] According to selective operations of the first and second dog clutches D1 and D2 of the dog clutch unit DC, torque of the motor / generator MG is input as assist torque to the planetary gear set portion PG, thereby achieving a hybrid mode.

[0086] In eCVT1 Mode, engine ENG operates at a fixed speed, and the first clutch C1 is engaged to transmit the torque of engine ENG to the first rotation element N1. Simultaneously, the second dog clutch D2 is engaged to transmit the torque of the motor / generator MG to the second rotation element N2, and the speed of the motor / generator MG is varied to change the gear ratio of the transmission, thereby achieving a gear ratio for a low gear (gear ratio greater than 1.0).

[0087] In eCVT2 Mode, engine ENG operates at a fixed speed, and the second clutch C2 is engaged to transmit the torque of engine ENG to the second rotation element N2. Simultaneously, the first dog clutch D1 is engaged to transmit the torque of the motor / generator MG to the first rotation element N1, and the speed of the motor / generator MG is varied to change the gear ratio of the transmission, thereby achieving a gear ratio for a high gear (gear ratio of 1.0 to 2.5).

[0088] In EV mode, the first and second clutches C1 and C2 are released to disconnect the planetary gear set PG from the engine ENG, while the first dog clutch D1 is engaged to transmit the torque of the motor / generator MG to the first rotation element N1. Similar to the engine mode, the first and second brakes B1 and B2 are controlled to achieve three EV mode low-speed fixed gear positions. Additionally, the second dog clutch D2 is engaged to transmit the torque of the motor / generator MG to the second rotation element N2, and the second brake B2 is controlled to achieve one EV mode high-speed fixed gear position.

[0089] Here, the engine mode (hybrid mode), the eCVT1 mode, and the eCVT2 mode can be combined to achieve at least six-speed shift modes.

[0090] Furthermore, the third engine mode forward speed and the fourth engine mode forward speed, which have a 1:1 ratio and an overdrive range, respectively, can be used as the fifth forward speed and the sixth forward speed, respectively. The second engine mode forward speed can be used as the third forward speed. The first engine mode forward speed can be used as the first forward speed. The eCVT1 mode, which has a gear ratio suitable for a low gear, can be used as the second forward speed between the first and third forward speeds. The eCVT2 mode, which has a gear ratio suitable for a high gear, can be used as the fourth forward speed between the third and fifth forward speeds.

[0091] Hereinafter, operations of the power transmitting apparatus of the hybrid electric vehicle according to various exemplary embodiments are described in detail with reference to respective modes.

[0092] [Engine Mode First Forward Speed ​​(Hybrid Mode First Forward Speed)]

[0093] In the engine mode first forward speed, the engine ENG is operated, and the first clutch C1 and the first brake B1 are operated simultaneously.

[0094] Therefore, the second shaft TM2 of the planetary gear set portion PG functions as a fixed element by operation of the first brake B1. In a transient state, the torque of the engine ENG is input to the first rotation element N1 through the first shaft TM1 by operation of the first clutch C1.

[0095] Therefore, the speed-reduced output is transmitted to the sixth rotation element N6 of the planetary gear set portion PG, and torque of the engine mode first forward speed is output through the output gear OG connected to the sixth rotation element N6 via the fourth shaft TM4.

[0096] Here, when the first dog clutch D1 is engaged while the motor / generator MG is driven, the torque of the motor / generator MG is added to the first shaft TM1 , thereby achieving a hybrid mode first forward speed.

[0097] [Engine Mode Second Forward Speed ​​(Hybrid Mode Second Forward Speed)]

[0098] In the engine mode second forward speed, the engine ENG is operated, and the first clutch C1 and the first brake B2 are operated simultaneously.

[0099] Therefore, the third shaft TM3 of the planetary gear set portion PG functions as a fixed element by operation of the second brake B2 . In a transient state, the torque of the engine ENG is input to the first rotation element N1 through the first shaft TM1 by operation of the first clutch C1 .

[0100] Therefore, the speed-reduced output is transmitted to the sixth rotation element N6 of the compound planetary gear set CPG, and torque of an engine mode second forward speed is output through the output gear OG connected to the sixth rotation element N6 through the fourth shaft TM4.

[0101] Here, when the first dog clutch D1 is engaged while the motor / generator MG is driven, the torque of the motor / generator MG is added to the first shaft TM1 , thereby achieving a hybrid mode second forward speed.

[0102] [Engine Mode Third Forward Speed ​​(Hybrid Mode Third Forward Speed)]

[0103] In the engine mode third forward speed, the engine ENG is operated, and the first clutch C1 and the second clutch C2 are simultaneously operated.

[0104] Therefore, in the planetary gear set portion PG, the torque of the engine ENG is simultaneously input to the first shaft TM1 and the second and fifth rotation elements N2 and N5 by operations of the first and second clutches C1 and C2 .

[0105] Therefore, the input torque is directly output (at a ratio of 1:1) through the output gear OG connected to the sixth rotation element N6 via the fourth shaft TM4 , so that the torque of the engine mode third forward speed is output.

[0106] Here, when the first dog clutch D1 or the second dog clutch D2 is engaged while driving the motor / generator MG, torque of the motor / generator MG is input to the first shaft TM1 or the second shaft TM2 , thereby achieving a hybrid mode third forward speed.

[0107] [Engine Mode Fourth Forward Speed ​​(Hybrid Mode Fourth Forward Speed)]

[0108] In the engine mode fourth forward speed, the engine ENG is operated, and the second clutch C2 and the second brake B2 are operated simultaneously.

[0109] Therefore, the third shaft TM3 of the planetary gear set portion PG functions as a fixed element by operation of the second brake B2. In a transient state, the torque of the engine ENG is input to the second rotation element N2 and the fifth rotation element N5 through the second shaft TM2 by operation of the second clutch C2.

[0110] Therefore, the speed-increased output is transmitted to the sixth rotation element N6 of the planetary gear set unit PG, and torque of the engine mode fourth forward speed as the overspeed range is output through the output gear OG connected to the sixth rotation element N6 via the fourth shaft TM4.

[0111] Here, when the second dog clutch D2 is engaged while the motor / generator MG is driven, the torque of the motor / generator MG is added to the second shaft TM2 , thereby achieving the hybrid mode fourth forward speed.

[0112] In this engine mode, when the vehicle is stopped with engine ENG running, the first clutch C1 and the first dog clutch D1 may be operated to transmit torque of engine ENG to the motor / generator MG to generate electricity to charge the battery.

[0113] [eCVT1 mode]

[0114] In the eCVT1 mode, the engine ENG is operated at a fixed speed, and the first clutch C1 and the second dog clutch D2 are operated.

[0115] Therefore, in the planetary gear set unit PG, the torque of the engine ENG is transmitted to the first rotation element N1 through the first shaft TM1 by the operation of the first clutch C1, and at the same time, the torque of the motor / generator MG is transmitted to the second rotation element N2 and the fifth rotation element N5 through the second shaft TM2 by the operation of the second dog clutch D2.

[0116] In this state, by changing the rotation speed of the motor / generator MG, the eCVT1 mode having a gear ratio suitable for a low gear can be achieved.

[0117] [eCVT2 mode]

[0118] In the eCVT2 mode, the engine ENG is operated at a fixed speed, and the second clutch C2 and the first dog clutch D1 are operated.

[0119] Therefore, in the planetary gear set unit PG, the torque of the engine ENG is transmitted to the second rotation element N2 and the fifth rotation element N5 through the second shaft TM2 by the operation of the second clutch C2, and at the same time, the torque of the motor / generator MG is transmitted to the first rotation element N1 through the first shaft TM1 by the operation of the first dog clutch D1.

[0120] In this state, by changing the rotation speed of the motor / generator MG, the eCVT2 mode having a gear ratio suitable for a high gear can be achieved.

[0121] [EV mode first speed]

[0122] At the EV mode first speed, the first clutch C1 and the second clutch C2 are released to disconnect the engine ENG. In a transient state, the first brake B1 and the first dog clutch D1 are simultaneously operated, and the motor / generator MG is operated.

[0123] Therefore, the second shaft TM2 of the planetary gear set portion PG functions as a fixed element by operation of the first brake B1. In a transient state, the torque of the motor / generator MG is input to the first rotation element N1 through the first shaft TM1 by operation of the first dog clutch D1.

[0124] Therefore, the speed-reduced output is transmitted to the sixth rotation element N6 of the compound planetary gear set CPG, and torque of the EV mode first speed is output through the output gear OG connected to the sixth rotation element N6 through the fourth shaft TM4.

[0125] [EV mode second speed]

[0126] At the EV mode second speed, the first clutch C1 and the second clutch C2 are released to disconnect the engine ENG. In a transient state, the second brake B2 and the first dog clutch D1 are simultaneously operated, and the motor / generator MG is operated.

[0127] Therefore, the third shaft TM3 of the planetary gear set portion PG functions as a fixed element by operation of the second brake B2 . In a transient state, the torque of the motor / generator MG is input to the first rotation element N1 through the first shaft TM1 by operation of the first dog clutch D1 .

[0128] Therefore, the speed-reduced output is transmitted to the sixth rotation element N6 of the compound planetary gear set CPG, and torque of the EV mode second speed is output through the output gear OG connected to the sixth rotation element N6 through the fourth shaft TM4.

[0129] [EV mode third speed]

[0130] At the EV mode third speed, the first clutch C1 and the second clutch C2 are released to disconnect the engine ENG. In a transient state, the first dog clutch D1 and the second dog clutch D2 are simultaneously operated, and the motor / generator MG is operated.

[0131] Therefore, in the planetary gear set portion PG, the torque of the motor / generator MG is simultaneously input to the first shaft TM1 and the second and fifth rotation elements N2 and N5 by the operations of the first and second dog clutches D1 and D2. Therefore, the first and second planetary gear sets PG1 and PG2 rotate integrally.

[0132] Therefore, the input torque is directly output (at a ratio of 1:1) through the output gear OG connected to the sixth rotation element N6 through the fourth shaft TM4 , so that the torque of the EV mode third speed is output.

[0133] [EV mode 4th speed]

[0134] At the EV mode fourth speed, the first clutch C1 and the second clutch C2 are released to disconnect the engine ENG. In a transient state, the second brake B2 and the second dog clutch D2 are simultaneously operated, and the motor / generator MG is operated.

[0135] Therefore, by the operation of the second brake B2, the third shaft TM3 of the planetary gear set unit PG serves as a fixed element. In a transient state, by the operation of the second dog clutch D2, the torque of the motor / generator MG is input to the second rotation element N2 and the fifth rotation element N5 through the second shaft TM2.

[0136] Therefore, the speed-increased output is transmitted to the sixth rotation element N6 of the planetary gear set portion PG, and torque of the EV mode fourth forward speed is output through the output gear OG connected to the sixth rotation element N6 via the fourth shaft TM4.

[0137] Figure 4 is a second operational chart of the power transmitting apparatus of the hybrid electric vehicle according to various exemplary embodiments.

[0138] Reference Figure 4 , according to the power transmission apparatus of the hybrid electric vehicle of each exemplary embodiment, the shift pattern may be implemented according to the second operation map.

[0139] According to the second operation map, the eCVT1 mode and the eCVT2 mode are used to achieve a low-speed gear, ie, a speed ratio having a ratio higher than 1:1.

[0140] In addition, the gear 1:1 is combined with Figure 3The first operation diagram depicts the engine mode third forward speed (hybrid mode third forward speed) and has a high gear OD lower than a 1:1 gear ratio in combination with the Figure 3 The engine mode fourth forward speed (hybrid mode fourth forward speed) described in the first operation chart is the same.

[0141] In addition, you can Figure 3 The EV mode is achieved in the same manner as in the first operation diagram.

[0142] It is understandable that it can be combined with Figure 3 The same method as described in the first operation diagram is implemented according to Figure 4 The shifting pattern of the second operation chart is not described in detail.

[0143] Figure 5 is a schematic diagram of a power transmission apparatus of a hybrid electric vehicle according to various exemplary embodiments of the present invention.

[0144] Reference Figure 5 The power transmission device of the hybrid electric vehicle according to this exemplary embodiment is different from that of each exemplary embodiment in that the dog clutch unit DC as a two-way system (TWS) is replaced with two clutches C3 and C4.

[0145] That is, the first dog clutch D1 of the dog clutch unit DC is replaced with the third clutch C3 , and the second dog clutch D2 is replaced with the fourth clutch C4 .

[0146] Therefore, the power transmission device of the hybrid electric vehicle according to this exemplary embodiment is different from that of each exemplary embodiment only in that the third clutch C3 and the fourth clutch C4 are used instead of the first and second dog clutches D1 and D2 , and other features remain unchanged.

[0147] In addition, in the first and second operation charts, except that the third clutch C3 and the fourth clutch C4 are operated instead of the first and second dog clutches D1 and D2, the shifting mode can be achieved in the same manner as in the various exemplary embodiments of the present invention, so the shifting operation will not be described in detail.

[0148] Figure 6 is a schematic diagram of a power transmission apparatus of a hybrid electric vehicle according to various exemplary embodiments of the present invention.

[0149] Reference Figure 6The power transmission device of the hybrid electric vehicle according to this exemplary embodiment is different from that of the various exemplary embodiments in that the compound planetary gear set CPG is formed in a Ravingneaux type, combining the first planetary gear set PG1 of the double pinion planetary gear set and the second planetary gear set PG2 of the single pinion planetary gear set, sharing the first planet carrier and the ring gear, rather than forming a planetary gear set portion PG as a combination of the first planetary gear set PG1 and the second planetary gear set PG2, which are each a single pinion planetary gear set.

[0150] That is, the compound planetary gear set CPG is composed of a combination of a first planetary gear set PG1 and a second planetary gear set PG2 having a common planet carrier PC12 and a common ring gear R12, thereby forming a first rotation element N1, a second rotation element N2, a third rotation element N3 and a fourth rotation element N4, and a first shaft TM1, a second shaft TM2, a third shaft TM3 and a fourth shaft TM4 are connected thereto.

[0151] Therefore, the first shaft TM1 is fixedly connected to the first rotation element N1 (first sun gear S1 ), and is selectively connected to the input shaft IS and the motor shaft MS, thereby selectively serving as an input element.

[0152] The second shaft TM2 is fixedly connected to the second rotation element ( N2 ; common planet carrier PC12 ), selectively connected to the input shaft IS and the motor shaft MS to selectively function as an input element, and selectively connected to the transmission case to selectively function as a fixed element.

[0153] The third shaft TM3 is fixedly connected to the third rotation element ( N3 ; second sun gear S2 ), and is selectively connected to the transmission housing H, thereby selectively serving as a fixed element.

[0154] The fourth shaft TM4 is fixedly connected to the fourth rotation element N4 (common ring gear R12 ), and is fixedly connected to the output gear OG, thereby always serving as an output element.

[0155] In addition, the power transmission device of the hybrid electric vehicle according to the various exemplary embodiments is the same as that of the various exemplary embodiments of the present invention in arrangement of the four shafts TM1 to TM4 and the engaging elements, and thus will not be described in detail.

[0156] In addition, the shifting mode may be implemented in the same manner as in the first and second operation charts of various exemplary embodiments of the present invention, and thus the shifting operation will not be described in detail.

[0157] Figure 7is a schematic diagram of a power transmission apparatus of a hybrid electric vehicle according to various exemplary embodiments of the present invention.

[0158] Reference Figure 7 The power transmission apparatus of the hybrid electric vehicle according to each exemplary embodiment is different from the other exemplary embodiments in that the dog clutch unit DC as a two-way system (TWS) is replaced with two clutches C3 and C4.

[0159] That is, the first dog clutch D1 of the dog clutch unit DC is replaced with the third clutch C3 , and the second dog clutch D2 is replaced with the fourth clutch C4 .

[0160] Therefore, the power transmission apparatus of the hybrid electric vehicle according to various exemplary embodiments is different from other exemplary embodiments only in that the third clutch C3 and the fourth clutch C4 are used instead of the first and second dog clutches D1 and D2 , and other features remain unchanged.

[0161] In addition, in the first and second operation charts, except that the third clutch C3 and the fourth clutch C4 are operated instead of the first and second dog clutches D1 and D2, the shifting mode can be achieved in the same manner as in the various exemplary embodiments of the present invention, so the shifting operation will not be described in detail.

[0162] As described above, the power transmission device of the hybrid electric vehicle according to the exemplary embodiment employs only two planetary gear sets PG1 and PG2, thereby simplifying the transmission structure. Furthermore, an engine mode, each having six speeds, and a parallel hybrid mode, having two electronically controlled continuously variable transmission modes (eCVT modes), can be combined to achieve various shifting modes with more than four speeds, thereby reducing production costs and achieving higher fuel consumption characteristics and power performance than equivalent transmissions.

[0163] In addition, compared with a conventional six-speed transmission, the number of planetary gear sets employed can be reduced, and therefore, the overall length can be reduced, thereby improving mountability.

[0164] In addition, by adopting the dog clutch unit DC as a two-way system (TWS), an eCVT mode with a gear ratio suitable for low gear can be achieved, and when driving in city mode, fuel consumption can be improved by using the eCVT mode.

[0165] For ease of interpretation and accurate definition in the appended claims, the terms "upper," "lower," "inner," "outer," "upward," "downward," "front," "rear," "back," "inside," "outerside," "inward," "outward," "inner," "external," "inner," "outer," "forward," and "rearward" are used to describe features of the exemplary embodiments with reference to the positions of features shown in the figures. It should also be understood that the term "connect" or its derivatives refers to both direct and indirect connections.

[0166] The descriptions of specific exemplary embodiments of the present invention have been presented above for the purpose of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise embodiments disclosed, and it is apparent that several modifications and variations can be made in light of the above teachings. The exemplary embodiments selected and described are intended to explain certain principles of the present invention and their practical applications so that others skilled in the art can make and utilize various exemplary embodiments of the present invention, as well as alternatives and variations thereof. The scope of the present invention is intended to be defined by the appended claims and their equivalents.

Claims

1. A power transmission device for a hybrid electric vehicle, the power transmission device comprising: an input shaft configured to receive engine torque; a motor shaft configured to receive torque from the motor / generator; a first planetary gear set having a first rotating element, a second rotating element, and a third rotating 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 rotating element and selectively and independently connected to each of the input shaft and the motor shaft such that the first shaft is disconnected from one of the input shaft and the motor shaft while being connected to the other, or the first shaft is connected to both the input shaft and the motor shaft; a second shaft fixedly connecting the second rotating element and the fifth rotating element and selectively connected to the input shaft, the motor shaft, and a transmission case, respectively; a third shaft fixedly connecting the third rotating element and the fourth rotating element and selectively connected to the transmission housing; a fourth shaft fixedly connecting the sixth rotating element and the output gear; as well as A plurality of engagement elements includes at least one clutch and at least one brake.

2. The power transmission device according to 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, and 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 device according to claim 1, wherein: At least one clutch of the plurality of engagement elements comprises: a first clutch mounted between the first shaft and the input shaft; and a second clutch mounted between the second shaft and the input shaft; At least one brake of the plurality of engagement elements comprises: a first brake mounted between the second shaft and the transmission housing; and a second brake mounted between the third shaft and the transmission housing; and the plurality of engagement elements further comprising: a first dog clutch mounted between the first shaft and the motor shaft; and A second claw clutch is installed between the second shaft and the motor shaft.

4. The power transmission device according to claim 3, wherein: The first claw clutch comprises: a clutch drum connected to the motor shaft, having an inner periphery rotatably supported by the transmission case, and having a first drum gear and a second drum gear formed on an inner side and an outer side of the clutch drum, respectively; a first shaft gear formed on the first shaft; a first clutch piston installed inside the clutch drum, formed with a first guide gear engaged with the first drum gear, formed with a first clutch gear engaged with the first shaft gear to transmit the torque of the motor shaft to the first shaft, forming a first hydraulic chamber with the clutch drum, and supported by an elastic member; and A first reaction piston is installed inside the clutch drum, supported by a first snap ring, and forms a second hydraulic chamber with the first clutch piston.

5. The power transmission device according to claim 4, wherein: The second dog clutch shares a clutch drum with the first dog clutch, and The second claw clutch comprises: a second shaft gear formed on the second shaft; a second clutch piston mounted on the outside of the clutch drum, formed with a second guide gear engaged with a second drum gear, formed with a second clutch gear engaged with the second shaft gear to transmit the torque of the motor shaft to the second shaft, forming a first hydraulic chamber with the clutch drum, and supported by an elastic member; and A second reaction piston is installed on the outside of the clutch drum, supported by a second snap ring, and forms a second hydraulic chamber with the second clutch piston.

6. The power transmission device according to claim 1, wherein: At least one clutch of the plurality of engagement elements comprises: a first clutch mounted between the first shaft and the input shaft; a second clutch mounted between the second shaft and the input shaft; a third clutch installed between the first shaft and the motor shaft; and a fourth clutch installed between the second shaft and the motor shaft, wherein at least one brake among the plurality of engagement elements comprises: a first brake mounted between the second shaft and the transmission housing; and The second brake is installed between the third shaft and the transmission housing.

7. A power transmission device for a hybrid electric vehicle, the power transmission device comprising: an input shaft configured to receive engine torque; a motor shaft configured to receive torque from the motor / generator; a compound planetary gear set formed as a combination of a first planetary gear set and a second planetary gear set, the first planetary gear set and the second planetary gear set sharing a common planet carrier and a common ring gear, and having a first rotation element, a second rotation element, a third rotation element, and a fourth rotation element; a first shaft fixedly connected to the first rotating element and selectively and independently connected to each of the input shaft and the motor shaft such that the first shaft is disconnected from one of the input shaft and the motor shaft while being connected to the other, or the first shaft is connected to both the input shaft and the motor shaft; a second shaft connected to the second rotating element and selectively connected to the input shaft, the motor shaft, and a transmission case, respectively; a third shaft connected to the third rotating element and selectively connected to the transmission case; a fourth shaft fixedly connecting the fourth rotating element and the output gear; as well as A plurality of engagement elements includes at least one clutch and at least one brake.

8. The power transmission device according to claim 7, wherein: The compound planetary gear set is formed in a Ravilhoux type, the first planetary gear set is formed as a double pinion planetary gear set, and the second planetary gear set is formed as a single pinion planetary gear set.

9. The power transmission device according to claim 7, wherein: The compound planetary gear set includes a first sun gear as the first rotation element, a common planet carrier as the second rotation element, a second sun gear as the third rotation element, and a common ring gear as the fourth rotation element.

10. The power transmission device according to claim 7, wherein: At least one clutch of the plurality of engagement elements comprises: a first clutch mounted between the first shaft and the input shaft; and a second clutch mounted between the second shaft and the input shaft; At least one brake of the plurality of engagement elements comprises: a first brake mounted between the second shaft and the transmission housing; and a second brake mounted between the third shaft and the transmission housing; and the plurality of engagement elements include: The dog clutch unit includes a first dog clutch installed between the first shaft and the motor shaft; and a second dog clutch installed between the second shaft and the motor shaft.

11. The power transmission device according to claim 10, wherein: The first claw clutch comprises: a clutch drum connected to the motor shaft, having an inner periphery rotatably supported by the transmission case, and having a first drum gear and a second drum gear formed on an inner side and an outer side of the clutch drum, respectively; a first shaft gear formed on the first shaft; a first clutch piston installed inside the clutch drum, formed with a first guide gear engaged with the first drum gear, formed with a first clutch gear engaged with the first shaft gear to transmit the torque of the motor shaft to the first shaft, forming a first hydraulic chamber with the clutch drum, and supported by an elastic member; and A first reaction piston is installed inside the clutch drum, supported by a first snap ring, and forms a second hydraulic chamber with the first clutch piston.

12. The power transmission device according to claim 11, wherein: The second dog clutch shares a clutch drum with the first dog clutch, and The second claw clutch comprises: a second shaft gear formed on the second shaft; a second clutch piston mounted on the outside of the clutch drum, formed with a second guide gear engaged with the second drum gear, formed with a second clutch gear engaged with the second shaft gear to transmit the torque of the motor shaft to the second shaft, forming a first hydraulic chamber with the clutch drum, and supported by an elastic member; and A second reaction piston is installed on the outside of the clutch drum, supported by a second snap ring, and forms a second hydraulic chamber with the second clutch piston.

13. The power transmission device according to claim 7, wherein: At least one clutch of the plurality of engagement elements comprises: a first clutch mounted between the first shaft and the input shaft; a second clutch mounted between the second shaft and the input shaft; a third clutch installed between the first shaft and the motor shaft; and a fourth clutch installed between the second shaft and the motor shaft; and at least one brake among the plurality of engagement elements includes: a first brake mounted between the second shaft and the transmission housing; and The second brake is installed between the third shaft and the transmission housing.

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