Power transmission device for electric vehicle

Abstract

To provide a power transmission device for an electric vehicle facilitating package mounting of the vehicle by a speed reduction structure by a plurality of planetary gear sets.SOLUTION: According to an aspect of the present invention, there is provided a power train system of an electric vehicle including a first planetary gear set having a first sun gear, a first planetary gear, and a first carrier, a second planetary gear set having a second planetary gear and a first ring gear, and a third planetary gear set having a second sun gear, a third planetary gear, a second carrier, and a second ring gear.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power transmission device for an electric vehicle. [Background technology]

[0002] Conventionally, power transmission devices for electric vehicles transmit power through a meshing structure between external gears attached to multiple power transmission shafts, which takes up a lot of space in the vehicle, making package design difficult. In addition, the motor input shaft, the power transmission shaft with external gears, and the accelerator shaft are arranged in a row at a predetermined interval, which creates various restrictions when installing them in the vehicle.

[0003] Furthermore, the power transmission device of a conventional electric vehicle is composed of one gear, and vehicle speed can be controlled only by the motor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Republic of Korea Patent Publication No. 10-2007-0076773 (Published on July 25, 2007) Summary of the Invention [Problem to be solved by the invention]

[0005] In order to solve the above-mentioned problems, the present invention aims to provide a power transmission device for an electric vehicle that is easy to package and install in a vehicle by using a speed reduction structure with multiple planetary gear sets. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a first planetary gear set comprising a first sun gear rotatably mounted on one accelerator shaft, first planetary gears externally meshed with the first sun gear, and a first carrier supporting the first planetary gears; a second planetary gear set comprising a second planetary gear mounted on one side of the first planetary gears and supported by the first carrier together with the first planetary gears, and a first ring gear surrounding the second planetary gears and externally meshed with the second planetary gears; and a second planetary gear set rotatably mounted on the one accelerator shaft so as to face the first carrier. a third planetary gear set including a sun gear, a third planetary gear externally meshed with the second sun gear, a second carrier supporting the third planetary gear, and a second ring gear externally meshed with the third planetary gear so as to surround the third planetary gear; wherein a sleeve is provided between the first carrier and the second carrier, and the sleeve moves in a single-stage meshing direction to connect the power of the first carrier and the second sun gear, or moves in a two-stage meshing direction to connect the power of the first carrier and the second carrier.

[0007] The sleeve can be controlled to move axially to perform one-stage or two-stage meshing.

[0008] The sleeve may be constantly splined to a first hub provided on one side of the first carrier, and the first hub may face a second hub provided on one side of the second carrier.

[0009] The sleeve may include a first spline provided on an outer diameter portion and a second spline provided on an inner diameter portion, and when the sleeve is in a single-stage meshing operation, the first spline may mesh with a third spline provided on the inner diameter portion of the first hub, and the second spline may mesh with a fourth spline formed on one side of the second sun gear.

[0010] In addition, during two-stage engagement of the sleeve, the first spline may be engaged with the third spline, and the second spline may be engaged with a fifth spline provided on an outer diameter portion of the second hub.

[0011] Also, the second carrier may be connected to a differential device.

[0012] The differential device may include a case connected to the other side of the second carrier; a pinion gear connected to the case by a connecting shaft inside the case and rotatable around the connecting shaft; a one-side side gear meshed with one side of the pinion gear and connected to the one-side accelerator shaft; and a other-side side gear meshed with the other side of the pinion gear and connected to the other-side accelerator shaft.

[0013] Also, the one-side accelerator shaft may be connected to one-side driving wheel, and the other-side accelerator shaft may be connected to the other-side driving wheel.

[0014] Also, the first sun gear may be connected to an input shaft of a motor.

[0015] The input shaft may be a hollow shaft rotatably mounted on an outer diameter portion of the one accelerator shaft so as to transmit the power of the motor to the first sun gear.

[0016] In addition, the first ring gear and the second ring gear may be fixed to an axle housing.

[0017] The present invention facilitates packaging in a vehicle by using a reduction structure with multiple planetary gear sets. Furthermore, the present invention has two speed stages and is capable of low-speed vehicle speed control and high-speed vehicle speed control. Furthermore, since the present invention is configured with a plurality of planetary gear sets, it occupies less space when mounted on a vehicle. Furthermore, the present invention allows for speed change control by operating the sleeve. Furthermore, the present invention can reduce the number of parts compared to existing power transmission devices for electric vehicles, thereby reducing costs, weight, and simplifying the assembly process. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view of a power transmission device for an electric vehicle according to a preferred embodiment of the present invention; [Figure 2] 1 is a side cross-sectional view of a power transmission device for an electric vehicle according to a preferred embodiment of the present invention. [Figure 3] 1 is a diagram illustrating operation at one stage according to a preferred embodiment of the present invention. [Figure 4] 1 is a diagram illustrating a two-stage operation according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, when assigning reference numerals to components in each drawing, it should be noted that the same numerals are used to designate the same components even if they appear in different drawings. Furthermore, when describing the present invention, if it is determined that a detailed description of related well-known structures or functions may obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described, but the technical concept of the present invention is not limited thereto and may be modified and embodied in various ways by those skilled in the art.

[0020] FIG. 1 is a perspective view of a power transmission device for an electric vehicle according to a preferred embodiment of the present invention, and FIG. 2 is a side cross-sectional view of the power transmission device for an electric vehicle according to a preferred embodiment of the present invention.

[0021] 1 and 2, the planetary gear set PS1 may include a first planetary gear set PS2, a second planetary gear set PS2, and a third planetary gear set PS3 to which power from the motor MG is transmitted. The first planetary gear set PS1, the second planetary gear set PS2, and the third planetary gear set PS3 may be mounted inside an axle housing (not shown).

[0022] The first planetary gear set PS1 may include a first sun gear S1, a first planetary gear P1, and a first carrier C1. Power transmitted to the first sun gear S1 may be transmitted to the first planetary gear P1.

[0023] The first sun gear S1 may be rotatably mounted on the outer diameter portion of one axle shaft 31. A plurality of first planetary gears P1 may be arranged along the outer diameter portion of the first sun gear S1. The first planetary gears P1 may be interlocked with the first sun gear S1 so as to be circumferentially ...

[0024] The first carrier C1 may support a first planetary gear P1. The first planetary gear P1 may be coupled to the first carrier C1 by a pin P. The first planetary gear P1 may rotate around the pin P.

[0025] The second planetary gear set PS2 may include a second planetary gear P2 and a first ring gear R1. Power transmitted to the second planetary gear P2 by the first planetary gear P1 may be transmitted to the first carrier C1.

[0026] The first planetary gear P1 and the second planetary gear P2 may be integrally formed. The second planetary gear P2 may rotate integrally with the first planetary gear P1. The second planetary gear P2 may be formed on one side of the first planetary gear P1. The second planetary gear P2 may be smaller in size than the first planetary gear P1. The second planetary gear P2 may be supported by the first carrier C1 together with the first planetary gear P1.

[0027] The pin P can be coupled to the first carrier C1 by passing through the center of the first planetary gear P1 and the second planetary gear P2 which are integrally formed.

[0028] The first ring gear R1 may be configured to surround the second planetary gear P2. The first ring gear R1 may be fixed F to an axle housing (not shown). The first ring gear R1 may be meshed with the second planetary gear P2 so as to circumscribe the second planetary gear P2.

[0029] The third planetary gear set PS3 may include a second sun gear S2, a third planetary gear P3, a second carrier C2, and a second ring gear R2. The power of the first carrier C1 may be transmitted to the second sun gear S2 or the second carrier C2.

[0030] The power transmitted from the first carrier C1 to the second sun gear S2 can be transmitted to the case 21 of the differential device 20 via the third planetary gear P3 and the second carrier C2.

[0031] The power transmitted from the first carrier C1 to the second carrier C2 can be transmitted to the case 21 of the differential device 20.

[0032] The second sun gear S2 may be configured to face the first carrier C1 and may be rotatably mounted on an outer diameter portion of one axle shaft 31.

[0033] A plurality of third planetary gears P3 may be arranged along the outer diameter portion of the second sun gear S2. The third planetary gears P3 may be meshed with the second sun gear S2 so as to circumscribe the second sun gear S2.

[0034] The second carrier C2 may support the third planetary gear P3. The third planetary gear P3 may be connected to the second carrier C2 by a pin P. The third planetary gear P3 may rotate around the pin P. The pin P may be coupled to the second carrier C2 so as to pass through the center of the third planetary gear P3.

[0035] The second ring gear R2 may be configured to surround the third planetary gear P3. The second ring gear R2 may be fixed F to an axle housing (not shown). The second ring gear R2 may be meshed with the third planetary gear P3 so as to circumscribe the outside of the third planetary gear P3.

[0036] A sleeve 10 may be provided between the first carrier C1 and the second carrier C2. The sleeve 10 may be splined to a first hub C1h provided on one side of the first carrier C1. The sleeve 10 may connect the power of the first carrier C1 and the second sun gear S2 while moving in the first-stage meshing direction. The sleeve 10 may connect the power of the first carrier C1 and the second carrier C2 while moving in the second-stage meshing direction.

[0037] The sleeve 10 can be moved axially by a control to perform a single-stage meshing operation or a two-stage meshing operation. For example, the control can be an actuator.

[0038] The sleeve 10 may be permanently splined to a first hub C1h of the first carrier C1. The first hub C1h may be configured to face a second hub C2h provided on one side of the second carrier C2.

[0039] The sleeve 10 may include a first spline 11 and a second spline 12. The first spline 11 may be provided on an outer diameter portion of the sleeve 10. The second spline 12 may be provided on an inner diameter portion of the sleeve 10.

[0040] During the first-stage engagement of the sleeve 10, the first spline 11 meshes with the third spline C1s provided on the inner diameter portion of the first hub C1h, and the second spline 12 meshes with the fourth spline S2s formed on one side of the second sun gear S2, thereby transmitting the power of the first carrier C1 to the second sun gear S2.

[0041] During the two-stage engagement of the sleeve 10, the first spline 11 can be engaged with the third spline C1s of the first hub C1h, and the second spline 12 can be engaged with the fifth spline C2s provided on the outer diameter portion of the second hub C2h, thereby transmitting the power of the first carrier C1 to the second carrier C2.

[0042] The other side of the second carrier C2 may be connected to the case 21 of the differential gear 20 by a connecting member BL such as a bolt. The connecting member BL may penetrate the case 21 of the differential gear 20 and be connected to the other side of the second carrier C2.

[0043] The power transmitted to the second carrier C2 can be transmitted to the case 21 of the differential device 20.

[0044] The differential device 20 may include a case 21, a pinion gear 22, one side gear 23, and the other side gear 24. The pinion gear 22, the one side gear 23, and the other side gear 24 may be mounted inside the case 21.

[0045] The power transmitted to the case 21 can be transmitted in both directions to the one side gear 23 and the other side gear 24 by the pinion gear 22 .

[0046] The pinion gear 22 may be connected to the case 21 by a connecting shaft 25. The connecting shaft 25 may be coupled to the outside of the case 21 so as to pass through the center of the pinion gear 22. The pinion gear 22 may rotate around the connecting shaft 25 inside the case 21.

[0047] The one-side side gear 23 may be meshed with one side of the pinion gear 22. The one-side side gear 23 may be connected to the one-side axle shaft 31. The one-side axle shaft 31 may be connected to the one-side driving wheel 41. The power transmitted to the one-side side gear 23 may be transmitted to the one-side driving wheel 41 via the one-side axle shaft 31.

[0048] The other side gear 24 may be meshed with the other side of the pinion gear 22. The other side gear 24 may be connected to the other side axle shaft 32. The other side axle shaft 32 may be connected to the other side driving wheel 42. The power transmitted to the other side side gear 24 may be transmitted to the other side driving wheel 42 via the other side axle shaft 32.

[0049] The first sun gear S1 may be connected to an input shaft IS of a motor MG, and power of the motor MG may be transmitted to the first sun gear S1 via the input shaft IS.

[0050] The input shaft IS may be a hollow shaft. The input shaft IS may be rotatably mounted on the outer diameter portion of one accelerator shaft 31.

[0051] The first sun gear S1, the first carrier C1, the second sun gear S2, the second carrier C2, and the case 21 can be supported by a bearing BA.

[0052] FIG. 3 is a diagram showing the operation of one stage according to a preferred embodiment of the present invention.

[0053] As shown in FIG. 3, the motor MG may be connected to an inverter INV.

[0054] The operation of the present invention at the first stage will now be described.

[0055] As shown in Figures 2 and 3, in the first stage, as the sleeve 10 moves in the first stage meshing direction, the first spline 11 of the sleeve 10 meshes with the third spline C1s of the first hub C1h, and the second spline 12 of the sleeve 10 meshes with the fourth spline S2s of the second sun gear S2.

[0056] The first spline 11 of the sleeve 10 is meshed with the third spline C1s of the first hub C1h, and the second spline 12 of the sleeve 10 is meshed with the fourth spline S2s of the second sun gear S2, thereby connecting the power of the first carrier C1 and the second sun gear S2.

[0057] With the power of the first carrier C1 and the power of the second sun gear S2 connected, the power of the motor MG can be transmitted to the first sun gear S1 via the input shaft IS.

[0058] The power transmitted to the first sun gear S1 can be transmitted to the first carrier C1 via the first planetary gear P1 and the first planetary gear P1.

[0059] Since the first carrier C1 and the second sun gear S2 are in a power-coupled state, power transmitted to the first carrier C1 can be transmitted to the second carrier C2 via the second sun gear S2 and the third planetary gear P3. This power transmission process can achieve speed reduction.

[0060] Since one side of the second carrier C2 is connected to the case 21 of the differential 20, the power transmitted to the second carrier C2 can be transmitted to the case 21 of the differential 20.

[0061] The power transmitted to the case 21 can be transmitted in both directions to one side gear 23 and the other side gear 24 via the pinion gear 22 .

[0062] The power transmitted to the one-side side gear 23 can be transmitted to the one-side driving wheel 41 via the one-side axle shaft 31, and the power transmitted to the other-side side gear 24 can be transmitted to the other-side driving wheel 42 via the other-side axle shaft 32.

[0063] The operation of the present invention in two stages will now be described.

[0064] FIG. 4 is a diagram illustrating the two-stage operation according to a preferred embodiment of the present invention.

[0065] As shown in Figures 2 and 4, as the sleeve 10 moves in the two-stage meshing direction, the first spline 11 of the sleeve 10 can mesh with the third spline C1s of the first hub C1h, and the second spline 12 of the sleeve 10 can mesh with the fifth spline C2s of the second carrier C2.

[0066] The first spline 11 of the sleeve 10 is meshed with the third spline C1s of the first hub C1h, and the second spline 12 of the sleeve 10 is meshed with the fifth spline C2s of the second carrier C2, thereby connecting the power of the first carrier C1 and the second carrier C2.

[0067] With the power of the first carrier C1 and the power of the second carrier C2 connected, the power of the motor MG can be transmitted to the first sun gear S1 via the input shaft IS.

[0068] The power transmitted to the first sun gear S1 can be transmitted to the first carrier C1 via the first planetary gear P1 and the first planetary gear P1.

[0069] Since the first carrier C1 and the second carrier C2 are in a power-coupled state, the power transmitted to the first carrier C1 can be transmitted to the second carrier C2, and deceleration can be achieved through this power transmission process.

[0070] Since the other side of the second carrier C2 is connected to the case 21 of the differential 20, the power transmitted to the second carrier C2 can be transmitted to the case 21 of the differential 20.

[0071] The power transmitted to the case 21 can be transmitted in both directions to one side gear 23 and the other side gear 24 via the pinion gear 22 .

[0072] The power transmitted to the one-side side gear 23 can be transmitted to the one-side driving wheel 41 via the one-side axle shaft 31, and the power transmitted to the other-side side gear 24 can be transmitted to the other-side driving wheel 42 via the other-side axle shaft 32.

[0073] As described above, the present invention is easily installed in a vehicle package due to its speed reduction structure using multiple planetary gear sets. Furthermore, the present invention has two speed stages, allowing for low-speed vehicle speed control and high-speed vehicle speed control. Furthermore, the present invention is configured with multiple planetary gear sets, so it occupies less space when installed in a vehicle. Furthermore, the present invention can control speed changes through the operation of a sleeve. Furthermore, the present invention has fewer parts than existing electric vehicle power transmission devices, resulting in lower costs, lighter weight, and a simplified assembly process.

[0074] The above description merely exemplifies the technical concept of the present invention, and those skilled in the art will recognize that various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments and accompanying drawings disclosed in the present invention are intended to illustrate, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments and accompanying drawings. The scope of protection of the present invention should be interpreted by the claims, and all technical concepts within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0075] PS1: First planetary gear set S1: First sun gear P1: First planetary gear C1: First carrier C1h: First Hub C1s...3rd spline PS2: Second planetary gear set P2: Second planetary gear R1: First ring gear PS3 3rd Planetary Gear Set S2: Second sun gear S2s: Fourth spline P3: Third planetary gear C2: Second Carrier C2h: Secondary Hub C2s 5th spline R2: Second ring gear MG···Motor IS Input shaft INV ···Inverter BA Bearing BL...connecting member P... Pin F...Fixed 10 Sleeve 11 First spline 12...2nd spline 20 Differential device 21 Case 22 Pinion gear 23 One side gear 24 Other side gear 25...Connection shaft 31 One side accelerator shaft 32 Other side accelerator shaft 41 One side drive wheel 42 Other drive wheel

Claims

1. a first planetary gear set including a first sun gear rotatably mounted on one axle shaft, a first planetary gear externally meshed with the first sun gear, and a first carrier supporting the first planetary gear; a second planetary gear set configured on one side of the first planetary gear and supported by the first carrier together with the first planetary gear, and a first ring gear externally meshed with the second planetary gear so as to surround the second planetary gear; and a third planetary gear set including a second sun gear rotatably mounted on the one axle shaft so as to face the first carrier, a third planetary gear externally meshed with the second sun gear, a second carrier supporting the third planetary gear, and a second ring gear externally meshed with the third planetary gear so as to surround the third planetary gear; Including, A sleeve is provided between the first carrier and the second carrier, and the sleeve connects the power of the first carrier and the second sun gear while moving in a first-stage meshing direction, or connects the power of the first carrier and the second carrier while moving in a second-stage meshing direction. A power transmission device for an electric vehicle, characterized in that:

2. The sleeve is It moves axially by control and performs one-stage or two-stage meshing operation.

2. The power transmission device for an electric vehicle according to claim 1.

3. The sleeve is constantly splined to a first hub provided on one side of the first carrier, and the first hub faces a second hub provided on one side of the second carrier.

2. The power transmission device for an electric vehicle according to claim 1.

4. The sleeve is a first spline provided on the outer diameter portion; and a second spline provided on the inner diameter portion; Including, When the sleeve is in a first-stage engagement, the first spline is engaged with a third spline provided on an inner diameter portion of the first hub, and the second spline is engaged with a fourth spline formed on one side of the second sun gear.

4. The power transmission device for an electric vehicle according to claim 3.

5. When the sleeve is in a two-stage engagement, the first spline is engaged with the third spline, and the second spline is engaged with a fifth spline provided on the outer diameter portion of the second hub.

5. The power transmission device for an electric vehicle according to claim 4.

6. The second carrier is Connected to the differential 2. The power transmission device for an electric vehicle according to claim 1.

7. The differential device comprises: a case connected to the other side of the second carrier; a pinion gear connected to the case by a connecting shaft inside the case and rotatable around the connecting shaft; a side gear that is meshed with one side of the pinion gear and is connected to the accelerator shaft; and an other side gear that is meshed with the other side of the pinion gear and is connected to the other accelerator shaft; Contains 7. The power transmission device for an electric vehicle according to claim 6.

8. The one-side accelerator shaft is connected to one-side driving wheel, and the other-side accelerator shaft is connected to the other-side driving wheel.

8. The power transmission device for an electric vehicle according to claim 7.

9. The first sun gear is connected to an input shaft of a motor.

2. The power transmission device for an electric vehicle according to claim 1.

10. The input shaft A hollow shaft rotatably mounted on the outer diameter portion of the one accelerator shaft so as to transmit the power of the motor to the first sun gear.

10. The power transmission device for an electric vehicle according to claim 9.

11. The first ring gear and the second ring gear are Fixed to the accelerator housing 2. The power transmission device for an electric vehicle according to claim 1.

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