Powertrain systems for electric vehicles

Abstract

A powertrain for an electric vehicle includes a planetary gear comprising a first rotating element, a second rotating element, and a third rotating element, wherein the first rotating element is connected to a first shaft, the second rotating element is connected to a second shaft, and the third rotating element is connected to a third shaft; a first electric motor selectively provides power to the first shaft at two or more gear ratios; and a second electric motor selectively provides power to the first shaft and the second shaft. The third shaft is fixedly mounted on a transmission housing, and any two of the first, second, and third shafts are mutually constrained.

Description

Technical Field

[0001] The present disclosure relates to a technology of a powertrain provided in an electric vehicle. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] Electric vehicles (EVs) are vehicles that use electric motors for propulsion. Since they produce no emissions, these vehicles can significantly contribute to reducing environmental pollution in metropolitan areas.

[0004] In order to popularize such electric vehicles, various technologies need to be improved. In particular, technologies that significantly increase the drivable range after a single charge are desired.

[0005] To increase the drivable range, the vehicle should be able to meet the maximum slope and maximum speed required by the vehicle, while improving fuel efficiency (i.e., drivable range per unit of electrical energy (km / kWh)) by reducing the size and capacity of the motor installed in the electric vehicle. In this regard, a transmission is arranged in the electric vehicle.

[0006] For the above reasons, the transmission arranged in the electric vehicle has high power transmission efficiency due to a relatively simple configuration while avoiding torque interruption or shift shock that interrupts the torque transmitted to the drive wheels during shifting.

[0007] The information disclosed in the background of this disclosure section is only for enhancement of understanding of the background of the disclosure and should not be regarded as an admission or any form of suggestion that this information forms the prior art already known to a person skilled in the art. Summary of the Invention

[0008] The present disclosure provides a power system for an electric vehicle, and the power system is capable of meeting the maximum gradient and maximum speed required by the vehicle, while reducing the capacity of the motor by providing multiple speed ratios, thereby improving the electrical efficiency of the vehicle by achieving high power transmission efficiency using a relatively simple structure and relatively small weight, and preventing torque interruption and speed change shock.

[0009] According to one aspect of the present disclosure, a power system for an electric vehicle may include: a planetary gear having three rotating elements (i.e., a first, second, and third rotating elements), wherein the first rotating element is connected to a first shaft and the second rotating element is connected to a second shaft; a first motor installed to selectively provide power to the first shaft at two or more gear ratios; and a second motor installed to selectively provide power to the first shaft and the second shaft.

[0010] The third rotation element of the planetary gear may be selectively connected to the transmission case, and two rotation elements among the three rotation elements of the planetary gear may be selectively connected to each other so that the entire planetary gear rotates integrally.

[0011] A first speed change assembly may be provided between the first motor and the first shaft to switch between a state in which power provided by the first motor is directly transmitted to the first shaft and a state in which the power provided by the first motor is shifted through a gear train before being transmitted to the first shaft.

[0012] In one embodiment, the rotating shaft of the first motor is coaxial with the first shaft. The first speed change assembly may include a gear engagement unit having a hub and a sleeve disposed on the rotating shaft of the first motor. A first gear may be rotatably disposed on the rotating shaft of the first motor, the first gear including a clutch gear configured to engage with the sleeve of the gear engagement unit. A second gear may be disposed on the first shaft such that rotation of the second gear is restricted, the second gear including a clutch gear configured to engage with the sleeve of the gear engagement unit.

[0013] The third gear externally meshed with the first gear and the fourth gear externally meshed with the second gear may be coaxially connected to each other.

[0014] A first speed transmission assembly may be disposed between the first motor and the first shaft such that power provided by the first motor is transmitted to the first shaft through one of two externally meshing gear trains having different gear ratios.

[0015] In some forms of the present disclosure, the first speed change assembly may include a gear meshing unit having a hub and a sleeve disposed on a rotating shaft of the first motor. The first gear and the second gear may be rotatably disposed on either side of the hub. A third gear externally meshed with the first gear and a fourth gear externally meshed with the second gear may be coaxially connected to each other. A fifth gear may be arranged on an axis between the third gear and the fourth gear such that rotation of the fifth gear is restricted. A sixth gear externally meshed with the fifth gear may be disposed on the first axis such that rotation of the sixth gear is restricted.

[0016] In some forms of the present disclosure, the seventh gear can be connected to the first shaft so that the rotation of the seventh gear is restricted. The eighth gear can be connected to the second shaft so that the rotation of the eighth gear is restricted. The ninth gear that is externally meshed with the seventh gear and the tenth gear that is externally meshed with the eighth gear can be arranged coaxially with each other. The second motor can be arranged to be connectable to the first shaft and the second shaft via a second speed change assembly arranged between the ninth gear and the tenth gear.

[0017] In some forms of the present disclosure, the second speed shift assembly may include a gear engaging unit having a hub and a sleeve disposed on the rotation shafts of the ninth gear and the tenth gear.

[0018] In another form, the second motor may be coaxially disposed on the first shaft. The second motor may be configured such that power provided by the second motor is transmitted to the first shaft or the second shaft via an eleventh gear and a twelfth gear, the eleventh gear being coaxially disposed on the first shaft, and the twelfth gear being externally meshed with the eleventh gear to be coaxial with the ninth gear and the tenth gear.

[0019] The power system may further include a third speed change assembly that fixes the third rotation element of the planetary gear to the transmission case or connects the third rotation element of the planetary gear to the second shaft through linear displacement in the axial direction of the first shaft.

[0020] According to another aspect of the present disclosure, a power system for an electric vehicle may include: a planetary gear having a first rotating element, a second rotating element, and a third rotating element, wherein the first rotating element is connected to a first shaft, the second rotating element is connected to a second shaft, and the third rotating element is connected to a third shaft; a first motor configured to selectively provide power to the first shaft at two or more gear ratios; and a second motor configured to selectively provide power to the first shaft and the second shaft. The third shaft may be fixedly disposed on a transmission housing, and any two of the first, second, and third shafts may be constrained to each other.

[0021] In addition, according to another aspect of the present disclosure, a power system for an electric vehicle is provided. The power system may include: a planetary gear including three rotating elements (i.e., a first rotating element, a second rotating element, and a third rotating element), wherein the first rotating element is connected to the first shaft, the second rotating element is connected to the second shaft, and the third rotating element is selectively connected to the transmission housing; a first motor configured to always provide power to the first shaft; and a second motor configured to selectively provide power to the first shaft and the second shaft. Any two of the three rotating elements of the planetary gear are selectively connected to rotate the entire planetary gear as a whole.

[0022] The first rotation element of the planetary gear may be a sun gear; the second rotation element of the planetary gear may be a planet carrier; and the third rotation element of the planetary gear may be a ring gear.

[0023] In some forms of the present disclosure, the seventh gear can be connected to the first shaft in a restricted state, the eighth gear can be connected to the second shaft in a restricted state, the ninth gear that is externally meshed with the seventh gear and the tenth gear that is externally meshed with the eighth gear can be mounted coaxially with each other, and the second motor can be mounted to be connectable to the first shaft and the second shaft via a second speed change assembly mounted between the ninth gear and the tenth gear.

[0024] In some forms of the present disclosure, the second speed shift assembly may include a gear engaging unit having a hub and a sleeve disposed on the rotation shafts of the ninth gear and the tenth gear.

[0025] In some forms of the present disclosure, the second motor can be coaxially mounted on the first shaft; and the power of the second motor can be transmitted to the first shaft or the second shaft through the eleventh gear and the twelfth gear, the eleventh gear is coaxially mounted on the first shaft, and the twelfth gear is externally engaged with the eleventh gear to be coaxial with the ninth gear and the tenth gear.

[0026] In some forms of the present disclosure, the power system may further include a third speed change assembly configured to fix the third rotating element of the planetary gear to the transmission housing or connect the third rotating element of the planetary gear to the second shaft by linear displacement in an axial direction along the first shaft.

[0027] According to another aspect of the present disclosure, a powertrain for an electric vehicle is provided. The powertrain may include: a planetary gear comprising three rotating elements, wherein a first rotating element is connected to a first shaft, a second rotating element is connected to a second shaft, and a third rotating element is connected to a third shaft; a first electric motor configured to constantly provide power to the first shaft; and a second electric motor configured to selectively provide power to the first and second shafts. The third shaft is fixedly connected to a transmission housing, and any two of the first, second, and third shafts are configured to constrain each other.

[0028] In addition, according to another aspect of the present disclosure, a power system for an electric vehicle is provided. The power system may include: a planetary gear comprising three rotating elements, wherein a first rotating element is connected to a first shaft, a second rotating element is connected to a second shaft, and a third rotating element is selectively connected to a transmission housing; a second electric motor configured to always provide power to the second shaft; and a first electric motor configured to selectively provide power to the first shaft and the second shaft. Any two of the three rotating elements of the planetary gear are selectively connected to rotate the entire planetary gear as a whole.

[0029] In some forms of the present disclosure, the first rotating element of the planetary gear may be a sun gear; the second rotating element of the planetary gear may be a planet carrier; and the third rotating element of the planetary gear may be a ring gear.

[0030] In some forms of the present disclosure, a first speed transmission assembly may be disposed between the second motor and the second shaft and configured to switch between a state in which the power of the second motor is directly transmitted to the second shaft and a state in which the power of the second motor is transmitted to the first shaft through speed change of a gear train.

[0031] In some forms of the present disclosure, the rotating shaft of the second motor is coaxial with the second shaft; the first speed transmission assembly may include a gear meshing unit, the hub and sleeve of the gear meshing unit are arranged on the rotating shaft of the second motor; the first gear is rotatably mounted on the rotating shaft of the second motor, and the first gear includes a clutch gear meshed with the sleeve of the gear meshing unit; the clutch gear configured to mesh with the sleeve of the gear meshing unit can be mounted on the second shaft when the rotation of the clutch gear is restricted; and the second gear can be mounted on the first shaft and is configured to receive power from the second motor when the rotation of the second gear is restricted.

[0032] In some forms of the present disclosure, a third gear externally meshed with the first gear and a fourth gear externally meshed with the second gear may be coaxially connected to each other.

[0033] In some forms of the present disclosure, the power system may further include a third speed change assembly configured to fix the third rotating element of the planetary gear to the transmission housing or connect the third rotating element of the planetary gear to the second shaft by linear displacement in an axial direction along the first shaft.

[0034] In some forms of the present disclosure, a first speed transmission assembly may be provided between the second motor and the first shaft to switch between a state in which the power of the second motor is directly transmitted to the first shaft and a state in which the power of the second motor is transmitted to the second shaft through speed change of a gear train.

[0035] In some forms of the present disclosure, the second motor can be arranged so that its rotating shaft is coaxial with the first shaft; the first speed transmission assembly may include a gear meshing unit, the hub and sleeve of the gear meshing unit are arranged on the rotating shaft of the second motor; the first gear can be rotatably mounted on the rotating shaft of the second motor, and the first gear includes a clutch gear that can mesh with the sleeve of the gear meshing unit; the clutch gear that can mesh with the sleeve of the gear meshing unit can be mounted on the first shaft when the rotation of the clutch gear is restricted; and the second gear can be mounted on the second shaft and is configured to receive power from the second motor when the rotation of the second gear is restricted.

[0036] In some forms of the present disclosure, a third gear externally meshed with the first gear and a fourth gear externally meshed with the second gear may be coaxially connected to each other.

[0037] In some forms of the present disclosure, the power system may further include a third speed change assembly configured to fix the third rotating element of the planetary gear to the transmission housing or connect the third rotating element of the planetary gear to the second shaft by linear displacement in an axial direction along the first shaft.

[0038] The present disclosure can reduce the capacity of a vehicle by providing multiple speed ratios while meeting the maximum climbing ability and maximum speed required by the vehicle, thereby improving the electrical efficiency of the vehicle by achieving high power transmission efficiency using a relatively simple structure and relatively small weight, and preventing torque interruption and speed shift shock.

[0039] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to facilitate understanding of the present disclosure, various forms of the present disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0041] Figure 1 is a diagram showing a first form of a power system for an electric vehicle according to the present disclosure;

[0042] Figure 2 is a diagram showing a second form of a power system for an electric vehicle according to the present disclosure;

[0043] Figure 3 is a table showing first to third forms of operating modes of a power system for an electric vehicle according to one form of the present disclosure;

[0044] Figure 4 is a diagram showing a third form of a power system for an electric vehicle according to one form of the present disclosure;

[0045] Figure 5 is a diagram showing a fourth form of a power system for an electric vehicle according to one form of the present disclosure;

[0046] Figure 6 is a diagram showing a fifth form of a power system for an electric vehicle according to one form of the present disclosure;

[0047] Figure 7 is a table showing fourth and fifth forms of operating modes of a power system for an electric vehicle according to one form of the present disclosure;

[0048] Figure 8 is a diagram showing a sixth form of a power system for an electric vehicle according to one form of the present disclosure; and

[0049] Figure 9 is a diagram showing a seventh form of a power system for an electric vehicle according to one form of the present disclosure.

[0050] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0051] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0052] Reference Figure 1 and Figure 2 , according to one form of the present disclosure, the first to third forms of a power system for an electric vehicle generally include: a planetary gear PG having three rotating elements (i.e., a first rotating element, a second rotating element, and a third rotating element), wherein the first rotating element is connected to the first shaft A1 and the second rotating element is connected to the second shaft A2; a first motor MG1, installed to selectively provide power to the first shaft A1 with two or more gear ratios; and a second motor MG2, installed to selectively provide power to the first shaft A1 and the second shaft A2.

[0053] The third rotation element of the planetary gear PG may be connected to the third shaft A3 and may be selectively connected to the transmission case CS.

[0054] In addition, two rotation elements arbitrarily selected from the three rotation elements of the planetary gear PG may be connected to each other so that the entire planetary gear PG may integrally rotate.

[0055] Here, when the first shaft A1 is regarded as an input shaft to which power can be transmitted from the first motor MG1 and the second motor MG2, and the second shaft A2 is regarded as an output shaft, power can be transmitted from the second motor MG2 to the output shaft and the shifted power can be output from the output shaft, the present disclosure can be configured so that the first motor MG1 provides power to the input shaft in an adjusted manner, and the power provided by the second motor MG2 to the input shaft or the output shaft can be readjusted using the planetary gear PG before being output to the output shaft.

[0056] For reference, the first axis A1, the second axis A2, and the third axis A3 are all concentrically arranged as the rotation axes of the rotation elements of the planetary gear PG. The first rotation element of the planetary gear PG can be referred to as a sun gear S, the second rotation element of the planetary gear PG can be referred to as a carrier C, and the third rotation element of the planetary gear PG can be referred to as a ring gear R.

[0057] For reference, the second shaft A2 in the drawings is denoted as OUT, and is shown as serving as an output shaft to which power is output.

[0058] Forms of the present disclosure generally include a third speed shift assembly S3 that fixes the third rotation element of the planetary gear PG to the transmission case CS or connects the third rotation element of the planetary gear PG to the second shaft A2 through linear displacement in the axial direction of the first shaft A1.

[0059] The third rotation element of the planetary gear PG is connected to the second rotation element via the second shaft A2 so that all rotation elements of the planetary gear PG can rotate integrally.

[0060] When the third shaft A3 is connected to the second shaft A2 as described above, and when the third shaft A3 is connected to the first shaft A1 or connects the first shaft A1 and the second shaft A2 , all rotation elements of the planetary gear PG may be configured to rotate integrally.

[0061] The third speed change assembly S3 may include, for example, a friction clutch, which can generate linear displacement by linear sliding along the axial direction when its rotation is restricted by the third shaft A3, thereby switching between a state in which the third rotating element of the planetary gear PG connected to the third shaft A3 is connected to the transmission housing CS and a state in which the third rotating element is connected to the second shaft A2.

[0062] exist Figure 1 In the first form shown, the first speed change assembly S1 is provided between the first motor MG1 and the first shaft A1 to switch between a state in which the power provided by the first motor MG1 is directly transmitted to the first shaft A1 and a state in which the power provided by the first motor MG1 is shifted through a gear train before being transmitted to the first shaft A1.

[0063] Specifically, the first motor MG1 is arranged so that its rotating shaft is coaxial with the first shaft A1, and the first speed change assembly S1 includes: a gear meshing unit, a hub and a sleeve of which are arranged on the rotating shaft of the first motor MG1; a first gear G1, which is rotatably arranged on the rotating shaft of the first motor MG1, and the first gear G1 includes a clutch gear that can mesh with the sleeve of the gear meshing unit; and a second gear G, which is arranged on the first rotating shaft A1 so that the rotation of the second gear G2 is restricted, and the second gear G includes a clutch gear that can mesh with the sleeve of the gear meshing unit.

[0064] Therefore, the first speed change assembly S1 substantially includes a gear meshing unit provided on the rotation shaft of the first motor MG1 , a clutch gear of the first gear G1 , a clutch gear of the second gear G2 , and the like.

[0065] In addition, the third gear G3 externally meshed with the first gear G1 and the fourth gear G4 externally meshed with the second gear G2 are coaxially connected to each other.

[0066] Therefore, when the sleeve of the first speed change assembly S1 meshes with the clutch gear of the first gear G1, the power provided by the first motor MG1 is transmitted to the first shaft A1 through the first gear G1, the third gear G3, the fourth gear G4, and the second gear G2 in sequence. When the sleeve of the first speed change assembly S1 meshes with the clutch gear of the second gear G2, the power provided by the first motor MG1 is directly transmitted to the first shaft A1. As a result, the power provided by the first motor MG1 can be transmitted to the first shaft A1 at various speed ratios.

[0067] in addition, Figure 2 The second form shown is different from the first form in that the first speed change assembly S1 is provided between the first motor MG1 and the first shaft A1 so that power provided by the first motor MG1 can be transmitted to the first shaft A1 through one of two externally meshing gears having different gear ratios.

[0068] Here, the first transmission assembly S1 includes a gear meshing unit whose hub and sleeve are arranged on the rotating shaft of the first motor MG1. The first gear G1 and the second gear G2 are rotatably arranged on either side of the hub. The third gear G3, which is externally meshed with the first gear G1, and the fourth gear G4, which is externally meshed with the second gear G2, are coaxially connected to each other. The fifth gear G5 is arranged on the shaft between the third gear G3 and the fourth gear G4, so that the rotation of the fifth gear G5 is restricted. The sixth gear G6, which is externally meshed with the fifth gear G5, is arranged on the first shaft A1, so that the rotation of the sixth gear G6 is restricted.

[0069] Therefore, when the sleeve of the first speed change assembly S1 meshes with the clutch gear of the first gear G1, power provided by the first motor MG1 is transmitted to the first shaft A1 via the first gear G1, the third gear G3, the fifth gear G5, and the sixth gear G6. When the sleeve of the first speed change assembly S1 meshes with the clutch gear of the second gear G2, power provided by the first motor MG1 is transmitted to the first shaft A1 via the second gear G2, the fourth gear G4, the fifth gear G5, and the sixth gear G6. As a result, power provided by the first motor MG1 can be transmitted to the first shaft A1 at different speed ratios.

[0070] For reference, another pair of externally meshing gears constructed in the same manner as the pair of externally meshing gears including the first gear G1 and the third gear G3 or the pair of externally meshing gears including the second gear G2 and the fourth gear G4 may be provided, and an additional transmission may be provided to connect the other pair of externally meshing gears to the first motor MG1. The power provided by the first motor MG1 can be transmitted at another speed ratio before being input to the first shaft A1 via the fifth gear G5 and the sixth gear G6.

[0071] The seventh gear G7 is connected to the first shaft A1, restricting its rotation. The eighth gear G8 is connected to the second shaft A2, restricting its rotation. The ninth gear G9, which externally meshes with the seventh gear G7, and the tenth gear G10, which externally meshes with the eighth gear G8, are coaxially arranged. The second motor MG2 is connected to the first shaft A1 and the second shaft A2 via the second transmission assembly S2, which is arranged between the ninth gear G9 and the tenth gear G10.

[0072] For reference, the seventh gear G7 to the tenth gear G10 and the second speed change assembly S2 are common components of the first and second forms. The second speed change assembly S2 includes a gear meshing unit whose hub and sleeve are arranged on the rotation shafts of the ninth gear G9 and the tenth gear G10.

[0073] Since the ninth gear G9 and the tenth gear G10 are respectively provided with clutch gears that mesh with the sleeve of the gear meshing unit, the second speed change assembly S2 essentially includes a gear meshing unit provided on the rotating shafts of the ninth gear G9 and the tenth gear G10, a clutch gear of the ninth gear G9, and a clutch gear of the tenth gear G10.

[0074] In addition, the second motor MG2 is coaxially arranged on the first shaft A1. The second motor G2 is configured so that power provided by the second motor G2 is transmitted to the first shaft A1 or the second shaft A2 via the eleventh gear G11 and the twelfth gear G12. The eleventh gear G11 is coaxially arranged on the first shaft A1, and the twelfth gear G12 is externally meshed with the eleventh gear G11 to be coaxial with the ninth gear G9 and the tenth gear G10.

[0075] Therefore, when the sleeve of the second speed-change assembly S2 meshes with the clutch gear of the ninth gear G9, the power provided by the second motor MG2 is transmitted to the first shaft A1 via the eleventh gear G11, the twelfth gear G12, the ninth gear G9, and the seventh gear G7. When the sleeve of the second speed-change assembly S2 meshes with the clutch gear of the tenth gear G10, the power provided by the second motor MG2 is transmitted to the second shaft A2 via the eleventh gear G11, the twelfth gear G12, the tenth gear G10, and the eighth gear G8.

[0076] Figure 3 : is a table showing first to third forms of operation modes of a power system for an electric vehicle according to the present disclosure, wherein a total of six gear stages are provided.

[0077] For reference, in the speed shift assembly, "a" indicates a configuration in which the sleeve of the first speed shift assembly S1 connects or disconnects the clutch gear of the first gear G1 to or from the power, "b" indicates a configuration in which the sleeve of the first speed shift assembly S1 connects or disconnects the clutch gear of the second gear G2 to or from the power, "c" indicates a configuration in which the sleeve of the second speed shift assembly S2 connects or disconnects the clutch gear of the ninth gear G9 to or from the power, "d" indicates a configuration in which the sleeve of the second speed shift assembly S2 connects or disconnects the clutch gear of the tenth gear G10 to or from the power, "e" indicates that the third speed shift assembly S3 is configured to connect the third rotating element of the planetary gear PG to or disconnect it from the transmission case CS, and "f" indicates that the third speed shift assembly S3 is configured to connect the third rotating element of the planetary gear PG to or disconnect it from the second shaft A2.

[0078] Reference Figure 1 In the form shown, the gear stages and shifting of the powertrain for an electric vehicle according to the present disclosure will be described. Figure 2 In the form shown, gear changes are performed essentially in the same manner.

[0079] The first gear stage is achieved by fixing the third rotation element of the planetary gear PG to the transmission case CS and meshing the sleeve of the first speed assembly S1 with the clutch gear of the first gear G1 and the sleeve of the second speed assembly S2 with the clutch gear of the ninth gear G9.

[0080] Here, the power provided by the first motor MG1 is transmitted to the first shaft A1 through the first gear G1, the third gear G3, the fourth gear G4 and the second gear G2. The power provided by the second motor MG2 is transmitted to the first shaft A1 through the eleventh gear G11, the twelfth gear G12, the ninth gear G9 and the seventh gear G7.

[0081] Therefore, the power provided by the first motor MG1 and the power provided by the second motor MG2 can both be transmitted to the first shaft A1. Depending on the driving condition of the vehicle, one of the two motors can be used to realize the driving of the first gear.

[0082] Since the ring gear R (i.e., the third rotating element of the planetary gear PG) is fixed to the transmission case CS through the third speed change assembly S3, the power transmitted to the first shaft A1 as described above is input from the first shaft A1 to the sun gear S (i.e., the first rotating element) and reduced by the planetary carrier C (i.e., the second rotating element) before being output to the second shaft A2.

[0083] The second shaft A2 is connected to one or more drive wheels via a separate differential device or the like, so that the vehicle can be propelled by the power transmitted as above.

[0084] The shift from the first gear stage to the second gear stage is performed by disengaging the sleeve of the first speed change assembly S1 from the clutch gear of the first gear G1 and meshing the sleeve of the first speed change assembly S1 with the clutch gear of the second gear G2 .

[0085] In this case, in a state where the torque of the first motor MG1 is reduced while allowing the second motor MG2 to continuously provide power, the sleeve of the first speed change assembly S1 is released from the neutral position and then engages with the clutch gear of the second gear G2, so that gear shifting can be performed smoothly without generating torque interruption or shift shock.

[0086] That is, even when the sleeve of the first speed change assembly S1 is disengaged and in neutral, the power provided by the second motor MG2 is continuously supplied to the first shaft A1, allowing torque to be continuously transmitted to one or more drive wheels, preventing torque interruption. During the disengagement and engagement of the sleeve of the first speed change assembly S1, the torque of the first motor MG1 is reduced or completely eliminated. As a result, the sleeve of the first speed change assembly S1 disengages and engages smoothly and gently, resulting in an excellent shifting feel.

[0087] In the second gear stage implemented in the above manner, the power provided by the first motor MG1 is directly transmitted to the first shaft A1 through the sleeve of the first speed shift assembly S1 and the second gear G2, and is reduced by the planetary gear PG before being output to the second shaft A2.

[0088] Shifting from the second gear stage to the third gear stage is performed by disengaging the sleeve of the second speed change assembly S2 from the clutch gear of the ninth gear G9 and engaging the sleeve of the second speed change assembly S2 with the clutch gear of the tenth gear G10.

[0089] Similarly, while allowing the first motor MG1 to continue to provide power to the first shaft A1 while reducing or releasing the torque of the second motor MG2, the sleeve of the second speed change assembly S2 is released from the clutch gear of the ninth gear G9 to be in a neutral position, and then engages with the clutch gear of the tenth gear G10, so that gear shifting can be performed smoothly without generating torque interruption or speed shift shock.

[0090] Therefore, while continuously providing the power provided by the first motor MG1 to the drive wheels, the sleeve of the second speed change assembly S2 is smoothly converted from a state in which the sleeve is engaged with the clutch gear of the ninth gear G9 to a state in which the sleeve is engaged with the clutch gear of the tenth gear G10, thereby completing the shift to the third gear stage.

[0091] In the third gear stage, power provided by the first motor MG1 is input to the sun gear S of the planetary gear PG through the first shaft A1, and power provided by the second motor MG2 is input to the carrier C of the planetary gear PG through the second shaft A2.

[0092] Reference Figure 3 The fourth through sixth gear stages are achieved with the third speed-change assembly S3 already connecting the third rotating element of the planetary gear PG to the second shaft A2. That is, in the first through third gear stages, the third speed-change assembly S3 secures the ring gear R (i.e., the third rotating element of the planetary gear PG) to the transmission case CS, reducing the power input to the first rotating element of the planetary gear PG before being output to the planet carrier C (i.e., the second rotating element) and the second shaft A2. In the fourth through sixth gear stages, the third speed-change assembly S3 connects the third rotating element of the planetary gear PG to the second rotating element via the second shaft A2, allowing the power input to the planetary gear PG to be output without reducing or increasing its speed.

[0093] To shift from third gear to fourth gear, the third rotating element of the planetary gear PG is fixed to the transmission case CS in third gear. Torque from the first motor MG1 is eliminated and the first speed assembly S1 is placed in a neutral position. The third rotating element of the planetary gear PG is connected to the second shaft A2 via the third speed assembly S3. The first speed assembly S1 is then controlled from the neutral position to engage the clutch gear of the first gear G1. In this way, power from the first motor MG1 is transmitted to the drive wheels, completing the shift. During the shift, power from the second motor MG2 is continuously supplied to the drive wheels via the second shaft A2, preventing torque interruption.

[0094] Next, a shift is performed from the fourth gear stage to the fifth gear stage. While the first motor MG1 continues to transmit power to the drive wheels, the torque of the second motor MG2 decreases, and the sleeve of the second speed change assembly S2 disengages from the clutch gear of the tenth gear G10 and then engages with the clutch gear of the ninth gear G9. Separately, a shift is performed from the fifth gear stage to the sixth gear stage. While the second motor MG2 continues to provide power to the drive wheels, the sleeve of the first speed change assembly S1 disengages from the clutch gear of the first gear G1 and then engages with the clutch gear of the second gear G2.

[0095] As described above, also in the shift from the fourth gear stage to the fifth gear stage and in the shift from the fifth gear stage to the sixth gear stage, the speed change can be performed in a state where one of the first motor MG1 and the second motor MG2 continuously transmits power to the drive wheels, thereby preventing torque interruption and obtaining a smooth speed change feeling.

[0096] Furthermore, because the powertrain for an electric vehicle according to the present disclosure is essentially configured to transmit power provided by the motor to the drive wheels using a related-art automated manual transmission (AMT), excellent power transmission efficiency is achieved. Specifically, in the sixth gear stage (i.e., the highest gear stage), power provided by the first motor MG1 is directly transmitted to the first shaft A1, and all rotating elements of the planetary gear PG are mutually constrained, causing the first shaft A1 to rotate integrally with the second shaft A2. As a result, the powertrain according to the present disclosure can output power provided by the first motor MG1 without shifting gears, thereby achieving significantly high power transmission efficiency and increasing or maximizing the fuel efficiency of the electric vehicle.

[0097] For reference, Figure 4 yes Figure 1 A modified form of the first form shown. Figure 4 In the illustrated form, the second motor MG2 and the gears connected to the second motor MG2 are moved to the right side of the planetary gear PG.

[0098] Furthermore, an output gear OG is provided on the carrier C of the planetary gear PG, and the ring gear RG of the differential DF directly meshes with the output gear OG.

[0099] In the first to third forms, the first speed change assembly S1 and the second speed change assembly S2 are provided together. Figure 5 The fourth form of Figure 6 The fifth form Figure 8 Sixth Form and Figure 9 The seventh form is a form in which only a speed change assembly identical to the first speed change assembly S1 or the second speed change assembly S2 is provided.

[0100] First, referring to the fourth and fifth forms, these two forms are commonly configured to include: a planetary gear PG having three rotating elements, a first rotating element of which is connected to the first shaft A1, a second rotating element of which is connected to the second shaft A2, and a third rotating element of which is selectively connected to the transmission case CS; a first motor MG1 is installed to always provide power to the first shaft A1; and a second motor MG2 is installed to selectively provide power to the first shaft A1 and the second shaft A2.

[0101] Any two rotation elements among the three rotation elements of the planetary gear PG may be selectively connected to each other so that the entire planetary gear PG may rotate integrally.

[0102] A first rotation element of the planetary gear PG is a sun gear S, a second rotation element of the planetary gear PG is a planet carrier C, and a third rotation element of the planetary gear PG is a ring gear R.

[0103] The seventh gear G7 is mounted in a restricted position on the first shaft A1, and the eighth gear G8 is mounted in a restricted position on the second shaft A2. A ninth gear G9, which externally meshes with the seventh gear G7, and a tenth gear G10, which externally meshes with the eighth gear G8, are mounted coaxially. The second motor MG2 is connected to the first shaft A1 and the second shaft A2 via a second speed change assembly S2, which is installed between the ninth gear G9 and the tenth gear G10.

[0104] The second speed shift assembly S2 includes a gear engaging unit in which a hub and a sleeve are provided on the rotation shafts of the ninth gear G9 and the tenth gear G10.

[0105] The second motor MG2 is coaxially mounted on the first shaft A1, and the power of the second motor MG2 is transmitted to the first shaft A1 or the second shaft A2 through the eleventh gear G11 and the twelfth gear G12. The eleventh gear G11 is coaxially mounted on the first shaft A1, and the twelfth gear G12 is externally engaged with the eleventh gear G11 and coaxially mounted on the ninth gear G9 and the tenth gear G10.

[0106] These forms are constructed to include a third speed change assembly S3 configured such that the third rotation element of the planetary gear PG is fixed to the transmission case CS or connected to the second shaft A2 by linear displacement along the axial direction of the first shaft A1.

[0107] That is to say, if Figure 7 As shown, the fourth and fifth forms are forms configured to use only the second speed change assembly S2 of the first to third forms, are almost similar to the first to third forms in other configurations and operations, and can achieve a total of four gear stages.

[0108] Figure 8 and Figure 9 The sixth and seventh aspects of the present disclosure are shown, respectively, and both include: a planetary gear comprising three rotating elements, wherein a first rotating element is connected to a first shaft, a second rotating element is connected to a second shaft, and a third rotating element is connected to a third shaft; a first electric motor is mounted to constantly provide power to the first shaft; a second electric motor is mounted to selectively provide power to the first shaft and the second shaft; the third shaft is fixedly mounted to a transmission case, and any two of the first, second, and third shafts are configured to constrain each other.

[0109] The first rotating element of the planetary gear is the sun gear, the second rotating element is the planet carrier, and the third rotating element is the ring gear.

[0110] exist Figure 8 In the sixth form, the first speed change assembly is provided between the second motor and the second shaft to switch between a state in which the power of the second motor is directly transmitted to the second shaft and a state in which the power of the second motor is shifted through the gear train and transmitted to the first shaft.

[0111] That is, the second motor is configured so that its rotating shaft is coaxial with the second shaft; the first speed change assembly includes a gear meshing unit, the hub and sleeve of the gear meshing unit are arranged on the rotating shaft of the second motor; the first gear is rotatably mounted on the rotating shaft of the second motor, the first gear including a clutch gear that can mesh with the sleeve of the gear meshing unit; the clutch gear that can mesh with the sleeve of the gear meshing unit is mounted on the second shaft in a state where the rotation of the clutch gear is restricted; and the second gear is mounted on the first shaft to receive power from the second motor in a state where the rotation of the second gear is restricted.

[0112] Furthermore, a third gear meshing with the outside of the first gear and a fourth gear meshing with the outside of the second gear are coaxially connected to each other.

[0113] Therefore, when the sleeve of the first speed change assembly S1 is moved to the left in the figure, the power of the second motor MG2 is transmitted to the first shaft A1 through the first gear G1, the third gear G3, the fourth gear G4, and the second gear G2 in sequence. When the sleeve of the first speed change assembly S1 is moved to the right in the figure, the power of the second motor MG2 can be transmitted to the second shaft A2 unchanged.

[0114] In some embodiments of the present invention, a third speed change assembly S3 is provided. The third speed change assembly S3 is configured so that the third rotation element of the planetary gear PG is fixed to the transmission case CS or connected to the second shaft A2 by linear displacement along the axial direction of the first shaft A1.

[0115] At the same time, Figure 9 In the seventh form, the first speed change assembly is provided between the second motor and the first shaft to switch between a state in which the power of the second motor is directly transmitted to the first shaft and a state in which the power of the second motor is shifted through the gear train and transmitted to the second shaft.

[0116] The second motor is configured so that its rotating shaft is coaxial with the first shaft; the first speed change assembly includes a gear meshing unit, a hub and a sleeve of which are arranged on the rotating shaft of the second motor; a first gear including a clutch gear that can mesh with the sleeve of the gear meshing unit is rotatably mounted on the rotating shaft of the second motor; the clutch gear that can mesh with the sleeve of the gear meshing unit is mounted on the first shaft in a state where the rotation of the clutch gear is restricted; and the second gear is mounted on the second shaft to receive power from the second motor in a state where the rotation of the second gear is restricted.

[0117] Furthermore, a third gear meshing with the outside of the first gear and a fourth gear meshing with the outside of the second gear are coaxially connected to each other.

[0118] Therefore, when the sleeve of the first speed change assembly S1 is moved to the left in the figure, the power of the second motor MG2 is directly transmitted to the first shaft A1. When the sleeve of the first speed change assembly S1 is moved to the right in the figure, the power of the second motor MG2 is transmitted to the second shaft A2 through the shifting of the first gear G1, the third gear G3, the fourth gear G4, and the second gear G2.

[0119] In some forms of the present disclosure, the third speed change assembly S3 is provided on the planetary gear PG. The third speed change assembly S3 is configured so that the third rotating element of the planetary gear PG is fixed to the transmission case CS or connected to the second shaft A2 by linear displacement along the axial direction of the first shaft A1.

[0120] Although exemplary forms of the present disclosure have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the disclosure.

Claims

1. A power system for an electric vehicle, the power system comprising: a planetary gear having a first rotating element, a second rotating element, and a third rotating element, wherein the first rotating element is connected to a first shaft and the second rotating element is connected to a second shaft; a first electric machine configured to selectively provide power to the first shaft in two or more gear ratios; and a second electric machine configured to selectively provide power to the first shaft and the second shaft, a seventh gear connected to the first shaft such that rotation of the seventh gear is restricted; an eighth gear connected to the second shaft such that rotation of the eighth gear is restricted; a ninth gear externally meshed with the seventh gear and a tenth gear externally meshed with the eighth gear being coaxially arranged with each other; and The second motor is arranged to be connectable to the first shaft and the second shaft via a second speed change assembly arranged between the ninth gear and the tenth gear.

2. The power system according to claim 1, wherein: The third rotating element of the planetary gear is selectively connected to a transmission case; and Two rotation elements among the first rotation element, the second rotation element, and the third rotation element of the planetary gear are selectively connected to each other and configured to integrally rotate the entire planetary gear.

3. The power system according to claim 2, further comprising a third speed change assembly configured to fix the third rotation element of the planetary gear to the transmission case or connect the third rotation element of the planetary gear to the second shaft through linear displacement in the axial direction of the first shaft.

4. The power system according to claim 1, wherein: A first speed change assembly is provided between the first motor and the first shaft to switch between a state in which power provided by the first motor is directly transmitted to the first shaft and a state in which the power provided by the first motor is shifted through a gear train before being transmitted to the first shaft.

5. The power system according to claim 4, wherein: The rotation shaft of the first motor is coaxial with the first shaft; The first transmission assembly includes a gear meshing unit, wherein a hub and a sleeve of the gear meshing unit are arranged on the rotating shaft of the first motor; A first gear is rotatably disposed on a rotation shaft of the first motor, the first gear including a clutch gear configured to mesh with the sleeve of the gear meshing unit; and A second gear is arranged on the first shaft such that rotation of the second gear is restricted, the second gear including a clutch gear configured to mesh with the sleeve of the gear meshing unit.

6. The power system according to claim 5, wherein: A third gear meshing with the outside of the first gear and a fourth gear meshing with the outside of the second gear are coaxially connected to each other.

7. The power system according to claim 1, wherein: A first speed transmission assembly is disposed between the first motor and the first shaft, such that power provided by the first motor is transmitted to the first shaft through one of two externally meshing gear trains having different gear ratios.

8. The power system according to claim 7, wherein: The first speed change assembly includes a gear meshing unit, wherein a hub and a sleeve of the gear meshing unit are arranged on the rotating shaft of the first motor; A first gear and a second gear are rotatably disposed on both sides of the hub; a third gear meshed with the outside of the first gear and a fourth gear meshed with the outside of the second gear connected to each other; a fifth gear being arranged on shafts of the third gear and the fourth gear so that rotation of the fifth gear is restricted; and A sixth gear that externally meshes with the fifth gear is disposed on the first shaft such that rotation of the sixth gear is restricted.

9. The power system according to claim 1, wherein: The second speed shift assembly includes a gear engaging unit, and a hub and a sleeve of the gear engaging unit are provided on the rotation shafts of the ninth gear and the tenth gear.

10. The power system according to claim 9, wherein: The second motor is coaxially arranged on the first shaft; and The power provided by the second motor is transmitted to the first shaft or the second shaft through the eleventh gear and the twelfth gear externally meshed with the eleventh gear. The eleventh gear is coaxially arranged on the first shaft, and the twelfth gear is coaxial with the ninth gear and the tenth gear.

11. A power system for an electric vehicle, the power system comprising: a planetary gear including three rotating elements, of which a sun gear is connected to a first shaft and a planet carrier is connected to a second shaft; a first electric machine configured to selectively provide power to the first shaft in two or more gear ratios; as well as a second electric machine configured to selectively provide power to the first shaft and the second shaft, a seventh gear connected to the first shaft such that rotation of the seventh gear is restricted; an eighth gear connected to the second shaft such that rotation of the eighth gear is restricted; a ninth gear externally meshed with the seventh gear and a tenth gear externally meshed with the eighth gear being coaxially arranged with each other; and The second motor is arranged to be connectable to the first shaft and the second shaft via a second speed change assembly arranged between the ninth gear and the tenth gear.

12. A power system for an electric vehicle, the power system comprising: a planetary gear including a first rotating element, a second rotating element, and a third rotating element, wherein the first rotating element is connected to the first shaft, the second rotating element is connected to the second shaft, and the third rotating element is selectively connected to a transmission case; a first motor configured to constantly provide power to the first shaft; and a second electric machine configured to selectively provide power to the first shaft and the second shaft, wherein two of the first rotating element, the second rotating element, and the third rotating element of the planetary gear are selectively connected to integrally rotate the entire planetary gear; a seventh gear connected to the first shaft in a restricted state; an eighth gear connected to the second shaft in a restricted state; A ninth gear meshing with the exterior of the seventh gear and a tenth gear meshing with the exterior of the eighth gear are coaxially mounted to each other; and The second motor is installed to be connectable to the first shaft and the second shaft via a second speed change assembly installed between the ninth gear and the tenth gear.

13. The power system of claim 12, wherein: The first rotating element of the planetary gear is a sun gear; The second rotating element of the planetary gear is a planet carrier; and The third rotation element of the planetary gear is a ring gear.

14. The power system according to claim 13, further comprising: A third speed change assembly is configured to fix the third rotation element of the planetary gear to the transmission case or connect the third rotation element of the planetary gear to the second shaft through linear displacement in the axial direction of the first shaft.

15. The power system according to claim 12, wherein: The second speed shift assembly includes a gear engaging unit, a hub and a sleeve of which are provided on the rotation shafts of the ninth gear and the tenth gear.

16. The power system of claim 15, wherein: The second motor is coaxially mounted on the first shaft; and The power of the second motor is transmitted to the first shaft or the second shaft through the eleventh gear and the twelfth gear, the eleventh gear is coaxially mounted on the first shaft, and the twelfth gear is externally meshed with the eleventh gear to be coaxial with the ninth gear and the tenth gear.

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