Power transmission device for hybrid vehicle

Abstract

Provided is a power transmission device for a hybrid vehicle, including: a connecting shaft, a rim portion connected to a mass by a connecting plate and combined to an outer side of a first rotor shaft connected to a first rotor of a first motor; and a driving plate, located on a crank shaft side opposite the connecting shaft, for connecting the mass and the crank shaft.

Description

Technical Field

[0001] This invention relates to a power transmission device for hybrid electric vehicles. Background Technology

[0002] Generally, the electric motors used in the power transmission system of hybrid vehicles are driven for electric travel when the engine is not initially driven. When two electric motors (P1 motor and P2 motor) are arranged in the power transmission system of a hybrid vehicle, one motor can be driven to start the engine, and the other motor can be driven for electric travel.

[0003] Figure 1 This is a diagram illustrating an existing power transmission system used in hybrid electric vehicles. (Reference) Figure 1 An existing power transmission device 1 for a hybrid electric vehicle includes: an electric motor housing 10 disposed between an engine 2 and a transmission 3; a first electric motor 20 disposed inside the electric motor housing 10 and connected to the crankshaft 2b of the engine 2; a second electric motor 30 disposed axially adjacent to the first electric motor 20 inside the electric motor housing 10 and connected to the input shaft 3b of the transmission 3; a torque damper 40 disposed between the first electric motor 20 and the second electric motor 30, with one side connected to the first electric motor 20; and a clutch 50 disposed on the second electric motor 30, selectively connecting the second electric motor 30 to the torque damper 40. The electric motor housing 10 is disposed between the engine 20 and the transmission 3 and is connected to the engine housing 2a and the transmission housing 3a. The motor housing 10 includes: a first motor housing 11, which is coupled to a first motor 20; and a second motor housing 12, which is coupled to a second motor 30. One side of the second motor housing 11 is connected to the first motor housing 11, and the other side is connected to the transmission housing 3a. The first motor housing 11 includes: a first cover 111, which is coupled to the second motor housing 12 and the engine 2, forming a first space S1 that can house at least a portion of the first motor 20; a second space S2, which is formed inside the second motor housing 12; and a first stator support. A support portion 112 is formed in the inner end of the first cover portion 111 that contacts the first space portion S1, for fixing the stator of the first motor 20; a first inner wall portion 113 extends from the first stator support portion 112 toward the first space portion S1 and is arranged opposite to the engine 2; a first rotor support portion 114 extends axially in the first inner wall portion 113 for supporting the rotor of the first motor 20; and a first opening portion 115 is formed in the central part of the first inner wall portion 113 to connect the rotor of the first motor 20 and the crankshaft 2b of the engine 2.

[0004] However, in existing power transmission devices for hybrid vehicles, the rotor shaft 20a and connecting shaft 2c of the P1 electric motor are splined together. To facilitate assembly, the splines have backlash. Due to this backlash, there is a gap in the spline tooth surfaces of the connecting shaft, which generates noise when the engine transmits power. Furthermore, when the engine clutch retainer forms the assembly hole, the working oil supplied between the engine clutch retainer and the engine clutch piston flows out to the bearing through the assembly hole, thus failing to form the working hydraulic pressure required for the engine clutch to operate, resulting in the engine clutch failing to operate.

[0005] In response, this invention proposes a mechanism that smoothly executes the operation of the engine clutch by connecting the engine's connecting shaft without gaps and sealing the assembly hole provided on the engine clutch retainer with a sealing cover, thereby forming working hydraulic pressure between the engine clutch retainer and the engine clutch piston.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent document 1: Korean Patent No. 10-2238845 (published on April 12, 2021). Summary of the Invention

[0009] To address the aforementioned problems, the present invention provides a power transmission device for hybrid electric vehicles. The device connects the engine's connecting shaft without gaps and seals the assembly hole provided on the engine clutch retainer with a sealing cap, thereby forming working hydraulic pressure between the engine clutch retainer and the engine clutch piston, thus smoothly executing the operation of the engine clutch.

[0010] To achieve the aforementioned objective, the present invention provides a power transmission device for a hybrid electric vehicle, comprising: a connecting shaft, a frame portion connected to a mass block via a connecting plate and coupled to the outside of a first rotor shaft connected to a first rotor of a first electric motor; and a drive plate, facing the connecting shaft and located on the crankshaft side, for connecting the mass block and the crankshaft.

[0011] Furthermore, the connecting shaft spline engages with the outer diameter of the first rotor shaft, which protrudes toward the crankshaft.

[0012] Furthermore, when coupled to the connecting shaft, the first rotor shaft portion exposed to the crankshaft side has a first stepped portion and a second stepped portion.

[0013] Furthermore, the first stepped portion has an outer diameter smaller than the outer diameter of the first rotor shaft portion, wherein the first rotor shaft is screwed with a lock nut on its outer periphery and splined with the connecting shaft.

[0014] Furthermore, the second stepped portion has an outer diameter smaller than that of the first stepped portion, and extends from the first stepped portion toward the crankshaft and is inserted into the interior of the crankshaft.

[0015] Furthermore, a first inner wall portion is provided between the mass block, the connecting plate and the first motor, and a hub surrounding the first rotor shaft is integrally formed at the center of the first inner wall portion. An oil seal for watertightness is provided between the outer diameter of the connecting shaft and the inner diameter of the hub.

[0016] Furthermore, the power transmission device for a hybrid electric vehicle of the present invention further includes: an engine clutch retainer disposed on the second motor side opposite to the first motor and having an assembly hole; a bolt for assembly through the assembly hole; and a sealing cap for sealing the assembly hole.

[0017] Furthermore, the engine clutch retainer is located between the input shaft support and the engine clutch piston.

[0018] Furthermore, the bolts are assembled into a bearing that is mounted on the input shaft support through the assembly hole.

[0019] Furthermore, the engine clutch retainer has a receiving portion that engages with a sealing cover, and the receiving portion communicates with the assembly hole provided on the bearing side of the input shaft support.

[0020] Furthermore, the bearing mounted on the input shaft support has a frame portion, which is disposed on the outer periphery of the bearing mounted on the input shaft support and has a mating hole for engaging the bolt.

[0021] Furthermore, the engine clutch retainer is integrated with the second rotor of the second electric motor located on the opposite side of the first electric motor.

[0022] Furthermore, the bearing mounted on the input shaft support rotatably supports the engine clutch retainer.

[0023] Furthermore, the first electric motor and the second electric motor are installed inside the housings of the first electric motor and the second electric motor, with the first electric motor connected to the crankshaft of the engine and the second electric motor connected to the input shaft of the transmission.

[0024] Furthermore, a torque damper is disposed between the first motor and the second motor, with one side of the torque damper connected to the first motor.

[0025] Furthermore, an engine clutch is provided in the second electric motor, which selectively connects the second electric motor and the torque damper.

[0026] Furthermore, the first motor housing is attached to one side of the second motor housing, and the gearbox is attached to the other side of the second motor housing.

[0027] Furthermore, the first motor housing has a first inner wall portion, on which a first decomposer is installed, and the second motor housing has a second inner wall portion, on which a second decomposer is installed.

[0028] Invention Effects

[0029] This invention prevents rattling noise when the engine transmits power by connecting the connecting shaft without gaps.

[0030] Furthermore, by sealing the assembly hole formed on the engine clutch retainer with a sealing cap, the present invention creates working hydraulic pressure between the engine clutch retainer and the engine clutch piston, thereby enabling the smooth operation of the engine clutch. Attached Figure Description

[0031] Figure 1 This is a diagram showing an existing power transmission device for hybrid vehicles.

[0032] Figure 2 This is a diagram illustrating a power transmission device for a hybrid electric vehicle according to a preferred embodiment of the present invention.

[0033] Figure 3 yes Figure 2 Enlarged view of part A.

[0034] 201: First motor housing; 202: Second motor housing; 203: Gearbox input shaft; 204: Gearbox; 210: Connecting shaft; 210a: Insertion part; 220: Drive plate; 221: Boss; 230: Connecting plate; 240: Mass block; 250: First motor; 250a: First rotor; 250b: First stator; 250c: First rotor sleeve; 251: First rotor shaft; 251c: First stepped part; 251d: Second stepped part; 260: Crankshaft; 271: First inner wall part; 271a: Hub; 271b: First resolver; 282: Second inner wall part; 282b: Second resolver. 290: Torque damper; 302: Second motor; 302a: Second rotor; 302b: Second stator; 310: Engine clutch retainer; 311: Assembly hole; 312: Receiving part; 320: Bearing; 321: Frame part; 321a: Engagement hole; 330: Engine clutch piston; 340: Bolt; 350: Sealing cover; 370: Input shaft support; 380: Engine clutch; 381: Engine clutch hub; 382: Second rotor shaft; BU: Bushing; L2: Lock nut; O1: O-ring; O2: Oil seal; OP: Engine clutch working hydraulic pressure; P: Pitch circle; S: Spline Detailed Implementation

[0035] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. First, it should be noted that when labeling the constituent elements in the drawings, the same symbols are used for the same constituent elements even when they are displayed on different drawings. In describing the present invention, detailed descriptions of related well-known structures or functions are omitted if it is determined that a specific description would obscure the essence of the invention. Furthermore, preferred embodiments of the present invention will be described below; however, the technical spirit of the present invention is not limited thereto, and various modifications can be made by those skilled in the art.

[0036] Figure 2 This is a diagram illustrating a power transmission device for a hybrid electric vehicle according to a preferred embodiment of the present invention. Figure 3 yes Figure 2 Enlarged view of part A.

[0037] like Figure 2 As shown, the present invention includes: a connecting shaft 210 connected to the first rotor shaft 251 of a first electric motor 250, and a frame connected to a mass block 240; and a drive plate 220 for connecting the mass block 240 to the crankshaft 260 of an engine. The first electric motor 250 includes a first rotor 250a and a first stator 250b.

[0038] The connecting shaft 210 is connected to the outer diameter spline S of the first rotor shaft 251. The connecting shaft 210 can be welded to the first rotor sleeve 250c of the first rotor 250a to form an integral part of the first rotor 250a.

[0039] With the connecting shaft 210 engaged with the first rotor shaft 251, the locking nut L2 is engaged at the part of the first rotor shaft 251 exposed to the crankshaft 260 side to lock the connecting shaft 210.

[0040] During assembly, the locking nut L2 can be inserted into the insertion part 210a, which is located close to one side of the connecting shaft 210.

[0041] The connecting shaft 210 can be connected to the mass block 240 via the connecting plate 230. As an example, the connecting plate 230 can be welded to the connecting shaft 210 and the mass block 240.

[0042] The center part of the connecting plate 230 can be connected to the connecting shaft 210, and the edge part of the connecting plate 230 can be connected to the mass block 240.

[0043] Mass block 240 (MASS) is a weight body that, when connecting shaft 210 rotates together with first rotor shaft 251, provides additional support for rotational inertia through the weight of mass block 240 to reduce vibration caused by rotational operation.

[0044] The drive plate 220 is located on the crankshaft 260 side of the engine, spaced apart from the connecting shaft 210 by a predetermined interval. A boss 221 is provided at the center of the drive plate 220.

[0045] With the crankshaft 260 engaged at the center of the boss 221 on the drive plate 220, bolts are used to assemble the boss 221 and the crankshaft 260.

[0046] The frame portion of the drive plate 220 is connected to the mass block 240. The drive plate 220 and the mass block 240 can be securely connected by bolts at the pitch circle P of the drive plate 220.

[0047] A first inner wall portion 271 may be provided between the assembly of the mass block 240 and the connecting plate 230 and the first motor 250. The first inner wall portion 271 may be integrally formed with the housing 201 of the first motor.

[0048] A hub 271a can be integrally formed at the center of the first inner wall portion 271. The hub 271a of the first inner wall portion 271 can be assembled into a structure surrounding the first rotor shaft 251 and the connecting shaft 210.

[0049] With the connecting shaft 210 assembled to the first rotor shaft 251, an oil seal O2 can be installed between the outer diameter of the connecting shaft 210 and the inner diameter of the hub 271a. The oil seal O2 can maintain water tightness between the outer diameter of the connecting shaft 210 and the inner diameter of the hub 271a.

[0050] The first rotor shaft 251 can be rotatably supported by a bearing 320 installed inside the hub 271a.

[0051] A first stepped portion 251c and a second stepped portion 251d can be sequentially formed from the joint portion of the first rotor shaft 251 that is coupled with the connecting shaft 210 toward the crank shaft 260.

[0052] The first step 251c and the second step 251d are the parts that are not connected to the connecting shaft 210.

[0053] The first stepped portion 251c is formed to be smaller than the outer diameter of the outer diameter portion of the first rotor shaft 251 that is coupled with the connecting shaft 210.

[0054] The first stepped portion 251c is the part that engages with the locking nut L2, and its width is formed to match the transverse width of the locking nut L2. A screw portion is formed on the outer periphery of the first stepped portion 251c, thereby allowing the locking nut L2 to be screwed into the first stepped portion 251c.

[0055] The second stepped portion 251d is connected to the first stepped portion 251c and extends from the first stepped portion 251c toward the crankshaft 260. The second stepped portion 251d is formed with an outer diameter smaller than that of the first stepped portion 251c.

[0056] For example, when assembling the connecting plate 230 and the first rotor shaft 251, bolts are used for assembly, which requires at least two bolts. However, in this invention, the connecting plate 230 and the first rotor shaft 251 can be assembled by a connecting shaft 210 connected to the connecting plate 230. Therefore, the number of assembly parts can be reduced compared to the existing assembly method using bolts.

[0057] As an example, preferably, after the first rotor shaft 251 is engaged with the connecting shaft 210, and the first step portion 251c is engaged with the locking nut L2, caulking is performed to prevent the locking nut L2 from loosening.

[0058] Since the second stepped portion 251d of the first rotor shaft 251 is inserted into the interior of the crankshaft 260, the first rotor shaft 251 and the crankshaft 260 can be securely assembled during assembly. Because the first rotor shaft 251 and the crankshaft 260 are securely assembled, the rotational balance of the first rotor 250a of the first motor 250 can be improved.

[0059] Furthermore, since the second step portion 251d is inserted into the inside of the crankshaft 260, it can stably support the first rotor shaft 251, thereby maintaining concentricity stably and reducing noise and vibration.

[0060] The spline connection between the connecting shaft 210 and the first rotor shaft 251, which are tightly attached to the locking nut L2, can be kept watertight by the O-ring O1. The O-ring O1 is pressed by the locking nut L2, so that it can fit tightly against the spline connection between the connecting shaft 210 and the first rotor shaft 251.

[0061] The torque damper 290 can be connected to the first rotor 250a of the first electric motor 250. The torque damper 290 is installed between the engine (not shown) and the transmission (not shown) to reduce the torsional vibration that occurs periodically on the transmission input shaft 203 during power transmission.

[0062] like Figure 2 and Figure 3 As shown, the engine clutch retainer 310 is integrated with the second rotor 302a, thereby also performing the rotor sleeve function of the second rotor 302a.

[0063] The engine clutch retainer 310 forms an assembly hole 311 through which the bolt 340 passes. After the bolt 340 is assembled through the assembly hole 311, the assembly hole 311 is sealed with a sealing cap 350 to prevent oil leakage through the assembly hole 311. This prevents leakage of the working hydraulic pressure (OP) of the engine clutch 380.

[0064] As an example, the sealing cover 350 can be configured in various ways to perform a sealing function, such as a structure in which a seal made of rubber material is attached to a steel plate.

[0065] The engine clutch retainer 310 is located between the bearing 320 mounted on the input shaft support 370 and the engine clutch piston 330.

[0066] As an example, the engine clutch retainer 310 can be integrated with the second rotor 302a of the second electric motor 302. The mounting hole 311 of the engine clutch retainer 310 extends through the bearing 320 mounted on the input shaft support 370.

[0067] As an example, the bearing 320 mounted on the input shaft support 370 can be a double ball bearing.

[0068] The second electric motor 302 includes a second rotor 302a and a second stator 302b.

[0069] The assembly hole 311 is preferably formed as a sufficiently large hole so that the bolt 340 can pass through freely when the bolt 340 is assembled.

[0070] Bolt 340 is engaged with the frame portion 321 of bearing 320 mounted on input shaft support 370. Bearing 320 mounted on input shaft support 370 can be securely engaged to input shaft support 370 by bolt 340.

[0071] After the bolts 340 are assembled, the assembly hole 311 is sealed by the sealing cap 350. Because the assembly hole 311 is sealed by the sealing cap 350, oil leakage through the assembly hole 311 can be prevented, thereby preventing leakage of the working hydraulic pressure OP of the engine clutch 380.

[0072] Because a hydraulic OP is formed between the engine clutch retainer 310 and the engine clutch piston 330, the operation of the engine clutch 380 can be smoothly performed.

[0073] A receiving portion 312 is provided in the engine clutch retainer 310. The receiving portion 312 is located on the side of the engine clutch piston 330, and the assembly hole 311 is located on the side of the bearing 320 mounted on the input shaft support 370. The receiving portion 312 and the assembly hole 311 are concentrically connected. The receiving portion 312 is formed by a hole larger than the assembly hole 311.

[0074] A frame portion 321 is provided on the bearing 320 mounted on the input shaft support 370. (Frame portion)

[0075] 321 extends outward from the outer periphery of the bearing 320 mounted on the input shaft support 370. A connecting hole 321a is formed in the frame portion 321. As an example, the connecting hole 321a is preferably formed...

[0076] The shape is designed to match the head of bolt 340, so that the head of bolt 340 can be accommodated.

[0077] With the bolt 340 inserted into the mating hole 321a through the assembly hole 311, the screw is engaged with the input shaft support 370.

[0078] The assembly bolt 340 is assembled with the screw engagement parts of the assembly hole 311, the mating hole 321a and the input shaft support 370 in a straight line 0.

[0079] With the bearing 320, which is mounted on the input shaft support 370, fixed to the input shaft support 370 by bolts 340, it rotatably supports the engine clutch retainer 310.

[0080] The first electric motor 250 and the second electric motor 302 are mounted on the first electric motor housing 201 and the second...

[0081] Inside the motor housing 202. A first motor 250 is connected to the engine crankshaft 260. A second motor 302 is connected to the transmission input shaft 203. A torque damper 290 is arranged between the first motor 250 and the second motor 302. One side of the torque damper 290 can be connected to the first motor 250.

[0082] An engine clutch 380 is provided on the second electric motor 302. The engine clutch 380 can selectively connect the second electric motor 302 and the torque damper 290.

[0083] The first motor housing 201 is attached to one side of the second motor housing 202. The second motor...

[0084] The housing 202 can be combined with the gearbox 204 on the other side.

[0085] The first motor housing 201 has a first inner wall portion 271. A first separator 271b can be mounted on the first inner wall portion 271. The second motor housing 202 has a second inner wall portion 282. A second separator 282b can be mounted on the second inner wall portion 282 or on the input shaft support 370.

[0086] 5. A sleeve BU can be installed between the first rotor shaft 251 and the torque damper 290.

[0087] A sleeve BU can be installed between the transmission input shaft 203 and the engine clutch hub 381. A second rotor shaft 382 can be positioned at the center of the engine clutch retainer 310. The second rotor shaft 382 is rotatably supported by a bearing 320 mounted on the input shaft support 370.

[0088] The second rotor shaft 382 is coupled to the outside of the transmission input shaft 203. The second rotor shaft 382 and the transmission input shaft 203 can be splined together.

[0089] The above description is merely illustrative of the technical spirit of the present invention, and those skilled in the art can make various modifications, alterations, and substitutions without departing from the essential characteristics of the invention. Therefore, the embodiments and drawings disclosed in this invention are not intended to limit but rather to explain the technical spirit of the invention, and the scope of the technical spirit of the invention should not be limited by the above embodiments and drawings. The scope of protection of this invention should be interpreted by the appended claims, and all technical spirit within their equivalents should be included within the scope of this invention.

Claims

1. A power transmission device for a hybrid electric vehicle, wherein, include: The connecting shaft and the frame portion are connected to the mass block via a connecting plate and are attached to the outside of the first rotor shaft connected to the first rotor of the first motor; A drive plate, facing the connecting shaft and located on the crankshaft side, is used to connect the mass block and the crankshaft. An engine clutch retainer is disposed on the second motor side opposite to the first motor and has an assembly hole; Bolts are assembled through the assembly holes; and A sealing cap for sealing the assembly hole.

2. The power transmission device for a hybrid electric vehicle according to claim 1, wherein, The connecting shaft spline engages with the outer diameter of the first rotor shaft, which protrudes toward the crankshaft.

3. The power transmission device for a hybrid electric vehicle according to claim 2, wherein, When coupled to the connecting shaft, the first rotor shaft portion exposed to the crankshaft side has a first stepped portion and a second stepped portion.

4. The power transmission device for a hybrid electric vehicle according to claim 3, wherein, The first stepped portion has an outer diameter smaller than the outer diameter of the first rotor shaft portion, wherein the first rotor shaft is screwed with a lock nut on its outer periphery and splined with the connecting shaft.

5. The power transmission device for a hybrid electric vehicle according to claim 4, wherein, The second stepped portion has a smaller outer diameter than the first stepped portion and extends from the first stepped portion toward the crankshaft and is inserted into the interior of the crankshaft.

6. The power transmission device for a hybrid electric vehicle according to claim 1, wherein, A first inner wall portion is provided between the mass block, the connecting plate and the first motor. A hub surrounding the first rotor shaft is integrally formed at the center of the first inner wall portion. An oil seal for watertightness is provided between the outer diameter of the connecting shaft and the inner diameter of the hub.

7. The power transmission device for a hybrid electric vehicle according to claim 1, wherein, The engine clutch retainer is located between the input shaft support and the engine clutch piston.

8. The power transmission device for a hybrid electric vehicle according to claim 7, wherein, The bolts are assembled into a bearing that is mounted on the input shaft support through the assembly hole.

9. The power transmission device for a hybrid electric vehicle according to claim 7, wherein, The engine clutch retainer has a receiving portion that engages with a sealing cover, and the receiving portion communicates with the assembly hole provided on the bearing side of the input shaft support.

10. The power transmission device for a hybrid electric vehicle according to claim 9, wherein, The bearing mounted on the input shaft support has a frame portion, which is disposed on the outer periphery of the bearing mounted on the input shaft support and has a mating hole for engaging the bolt.

11. The power transmission device for a hybrid electric vehicle according to claim 8, wherein, The engine clutch retainer is integrated with the second rotor of the second electric motor located on the opposite side of the first electric motor.

12. The power transmission device for a hybrid electric vehicle according to claim 9, wherein, The bearing mounted on the input shaft support rotatably supports the engine clutch retainer.

13. The power transmission device for a hybrid electric vehicle according to claim 8, wherein, The first electric motor and the second electric motor are installed inside the housing of the first electric motor and the housing of the second electric motor. The first electric motor is connected to the crankshaft of the engine, and the second electric motor is connected to the input shaft of the transmission.

14. The power transmission device for a hybrid electric vehicle according to claim 8, wherein, A torque damper is disposed between the first motor and the second motor, with one side of the torque damper connected to the first motor.

15. The power transmission device for a hybrid electric vehicle according to claim 14, wherein, An engine clutch is provided in the second electric motor, which selectively connects the second electric motor and the torque damper.

16. The power transmission device for a hybrid electric vehicle according to claim 8, wherein, The first motor housing is attached to one side of the second motor housing, and the gearbox is attached to the other side of the second motor housing.

17. The power transmission device for a hybrid electric vehicle according to claim 8, wherein, The first motor housing has a first inner wall portion, and a first decomposer is installed on the first inner wall portion. The second motor housing has a second inner wall portion, and a second decomposer is installed on the second inner wall portion or the input shaft support.

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