Hybrid drive unit and powertrain for a motor vehicle

Abstract

The present invention relates to a hybrid power drive unit (HY, G) for a motor vehicle, wherein the hybrid power drive unit (HY, G) has a housing (GG) in which a torque converter (TC) and an electric motor (EM) are housed, wherein the electric motor (EM) and the torque converter (TC) are arranged directly side by side, such that the electric motor (EM) is arranged at a first end side (TC1) of the torque converter housing (TCG), wherein an oil guide shell (LS) is provided, the oil guide shell partially surrounding a section of the torque converter (TC), wherein the oil guide shell (LS) has an L-shaped cross-section with a first section (LS1) and a second section (LS2), and the oil guide shell is arranged such that the first section (LS1) partially surrounds the second end side (TC2) of the torque converter housing (TCG), and the second section (LS2) partially surrounds the circumferential surface of the torque converter housing (TCG).

Description

Technical Field

[0001] The invention relates to a hybrid drive unit for a motor vehicle and to a drive train for a motor vehicle having such a hybrid drive unit. Background Art

[0002] The hybrid drive unit can be a component of a transmission that is adapted to form different transmission ratios between the combustion engine and the drive wheels of the motor vehicle. Alternatively, the hybrid drive unit can be designed as an independent structural unit that is arranged in the drive train between the combustion engine and the transmission. Such a structural unit is also referred to as a hybrid module.

[0003] For example, patent application DE 10 2014 118 485 A1 describes a mechanism for such a hybrid drive unit. The mechanism comprises a front module with an electric machine and a release clutch, a transmission behind the front module, a torque converter between the front module and the transmission, and a guide device radially between the torque converter and the transmission. The guide device divides a cavity that extends between the transmission housing and the housing of the torque converter, between the dry side and the wet side. The guide device is formed in a bathtub-like shape. The oil entering the dry side should be pumped out of the guide device by the rotation of the torque converter.

[0004] This configuration is considered disadvantageous because the oil cannot passively flow away from the "dry" side. Therefore, the operating performance of the powertrain may be limited, especially if the oil is very cold.

[0005] Patent application DE 10 2018 119 186 A1 describes a transmission assembly having a housing, an electric motor, a torque converter and a baffle. The baffle is arranged below the electric machine and adjacent to the torque converter. The baffle is intended to minimize contact of oil with the torque converter.

[0006] However, this solution cannot prevent the oil from coming into contact with the torque converter when a motor vehicle with such a transmission assembly is driven downhill or during severe braking. The baffles may even slow down the flow of oil after such an operating state. Summary of the invention

[0007] It is therefore an object of the present invention to provide a construction which enables the oil to flow away passively from the region of the torque converter.

[0008] This object is achieved by a hybrid drive unit for a motor vehicle according to the present invention, wherein the hybrid drive unit has a housing in which a torque converter and an electric machine are accommodated. The electric machine and the torque converter are arranged directly side by side in a common wet space, whereby the electric machine is arranged at a first end side of the torque converter housing. The rotor of the electric machine is connected to the housing of the torque converter. An oil guide shell is provided, which partially surrounds a section of the torque converter. The oil guide shell has an L-shaped cross-section with a first section and a second section, and the oil guide shell is arranged so that the first section partially surrounds the second end side of the torque converter housing, and the second section partially surrounds the circumferential surface of the torque converter housing.

[0009] The housing can be formed in one piece or in multiple pieces and accommodates at least one torque converter and an electric machine. The electric machine and the torque converter are arranged directly next to each other, whereby the electric machine is arranged at a first end side of the torque converter. The rotor of the electric machine is connected to the housing of the torque converter, whereby the rotor and the torque converter housing have the same rotational speed. In addition, an oil guide housing is provided, which partially surrounds a section of the torque converter.

[0010] According to the invention, it is now proposed that the oil guide housing has an L-shaped cross section, wherein the two parts of the L-shape are formed by a first section and a second section. Thus, unlike the guide device with a U-shaped cross section described in DE 10 2014 118 485 A1, the oil guide housing does not form a "bathtub-like" shape. The two sections of the L-shape are arranged here such that the first section partially surrounds the second end side of the torque converter and the second section partially surrounds the circumferential surface of the torque converter.

[0011] Due to the L-shaped cross section and the arrangement of the oil guide housing according to the present invention, the oil can be passively flowed away from the inner surface of the oil guide housing in the first end side direction of the torque converter. Here, the inner surface of the oil guide housing is the surface oriented toward the housing of the torque converter.

[0012] The oil guide housing is preferably arranged such that its second section partially surrounds the circumferential surface of the electric machine, in particular partially surrounds the stator of the electric machine when the electric machine is designed as an internal rotor. By means of this "extension" of the second section of the oil guide housing in the direction of the electric machine, oil can also be kept away from the torque converter in a simple manner when the motor vehicle with the hybrid drive unit is in a downhill position.

[0013] According to a preferred design, the electric machine can be cooled by supplying cooling oil. Here, the oil guide housing is designed and arranged so that a portion of the cooling oil flowing away from the electric machine is collected on the inner surface of the oil guide housing. This simply prolongs the time that the oil is in contact with the electric machine, thereby improving the cooling of the electric machine. Here, since the oil flows away passively in the direction of the first end side of the torque converter, clogging of the heated cooling oil is avoided in a simple manner.

[0014] The oil guide housing preferably surrounds only a portion of the axial extension of the electric machine, so that the cooling oil flowing away from the electric machine is only partially collected on the inner surface of the oil guide housing. With this solution, an effective compromise between efficient cooling of the electric machine and reducing the amount of oil in the region of the torque converter housing can be achieved.

[0015] Preferably, the oil guide housing and the housing of the hybrid drive unit are designed and arranged so that the portion of the cooling oil flowing away from the electric machine that is not collected on the inner surface of the oil guide housing is guided to the oil sump of the hybrid drive unit spatially below the oil guide housing.

[0016] According to a preferred design, a gap is formed between the inner surface of the oil guide housing and the housing of the torque converter. Here, the oil guide housing is arranged so that the cooling oil collected on the inner surface of the oil guide housing can flow into the gap. The defined gap enables the oil to be guided between the inner surface of the oil guide housing and the housing of the torque converter in a targeted manner.

[0017] Preferably, means are provided for discharging the cooling oil present in the gap, for example an oil scraping edge formed on the oil guide housing, an oil scraping edge formed or fastened on the housing of the hybrid drive unit, or an outflow channel leading to the oil sump of the hybrid drive unit. The oil scraping edge can be used to convey the oil present in the gap out of the gap by the rotational movement of the torque converter housing. In contrast, the outflow channel allows the oil to flow away passively.

[0018] Preferably, the oil guiding housing is connected to the housing in a rotationally fixed manner, thereby ensuring a defined position of the oil guiding housing.

[0019] According to a preferred design, the oil guide housing has a covering element, which partially covers the drive element of the oil pump of the hybrid drive unit. The amount of oil that comes into contact with the drive element can be reduced by means of such a covering element. This can further reduce the splash loss of the transmission.

[0020] According to a preferred embodiment, the oil guide housing is arranged such that in a horizontally oriented installation position of the hybrid drive unit, the spatially lowest point of the oil guide housing is spatially located below the oil level of the hybrid drive unit. A horizontally oriented installation position is understood here to be a state in which the hybrid drive unit is not tilted relative to its installation position in the motor vehicle, in particular neither to the side nor to the front or to the rear. Thus, in the horizontally oriented installation position, the hybrid drive unit occupies a position that corresponds to an installation position in the motor vehicle that is located on a plane. Even in this arrangement, the oil guide housing can contribute to reducing splash losses, because due to the rotational speed of the torque converter housing, more oil is transported from the inner surface of the oil guide housing than oil that is delivered from the oil sump or from the electric machine.

[0021] The hybrid drive unit may be a component of a motor vehicle drive train. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The embodiments of the present invention are described in detail below. In the accompanying drawings:

[0023] Figure 1 and Figure 2 each showing a schematic view of a motor vehicle powertrain;

[0024] Figures 3a to 5 each showing a schematic cross-sectional view of a hybrid drive unit of a motor vehicle powertrain;

[0025] Figures 6 to 8 Various views of an oil guide housing of a hybrid drive unit are shown; and

[0026] Fig. 9 A detail of a schematic sectional view of a hybrid drive unit is shown. DETAILED DESCRIPTION

[0027] Figure 1A powertrain for a motor vehicle is schematically shown. The powertrain has a combustion engine VM, the output of which is connected to the connecting shaft AN of a transmission G. The transmission G forms a hybrid powertrain unit of the powertrain and has an electric machine EM with a rotationally fixed stator ST and a rotatable rotor RO. The rotor RO is connected to the connecting shaft AN and to the housing TCG of the torque converter TC. The torque converter TC is connected to the input shaft GW1 of the transmission wheel set RS on the output side. The output shaft GW2 of the transmission wheel set RS is connected to the drive wheel DW of the motor vehicle via the differential AG. The housing TCG of the torque converter has a first end side TC1 and a second end side TC2. The electric machine EM and the torque converter TC are arranged directly side by side, whereby the electric machine EM is arranged directly at the first end side TC1 of the torque converter housing TCG.

[0028] Figure 2 A drive train is shown schematically, wherein no electric machine is contained in the transmission G. Instead, a hybrid module HY is provided between the combustion engine VM and the transmission G. In this embodiment, the hybrid module HY includes the electric machine EM, whereby the hybrid module HY forms the hybrid drive unit of the drive train. Figure 2 In the exemplary embodiment shown, the torque converter TC is also a component of the hybrid module HY. Alternatively, the torque converter TC can be a component of the transmission G.

[0029] Figure 3a A schematic cross-sectional view of a hybrid drive unit of a motor vehicle drive train is shown, in the illustrated embodiment as a transmission G with an electric machine EM. The transmission wheel set RS is composed, for example, of a combination of a plurality of planetary gear sets. Alternatively or in addition thereto, the transmission wheel set RS can be composed of a plurality of spur gear sets and / or of a belt drive (e.g. as a CVT transmission). The transmission wheel set RS, together with the switching elements arranged therein, is adapted to provide different transmission ratios between the input shaft GW1 and the output shaft GW2. The transmission wheel set RS is surrounded by a housing GG. The housing GG can be composed of a plurality of individual components.

[0030] The transmission G has a cavity NR on the input side. A torque converter TC and an electric machine EM are arranged in the cavity NR. The torque converter TC includes a pump wheel PR, a turbine TR and a stator LR, which act together fluidically in a known manner. The pump wheel PR is connected to the torque converter housing TCG. The connecting shaft AN is connected to the rotor RO and to the pump wheel PR via an optional separating clutch K0. The input shaft GW1 is connected to the turbine TR. The pump wheel PR and the turbine TR can be mechanically connected to each other by means of a locking clutch WK, so that in the closed state of the locking clutch WK, the torque converter TC is bridged. The stator LR is supported on the housing GG via a free wheel F. Additional components, such as one or more torsional vibration dampers and / or torsional vibration dampers, can be arranged in the cavity NR.

[0031] The transmission G also has an oil sump SU, an oil pump P, and a hydraulic control unit HCU. Figure 3a The oil level in the oil sump SU is indicated in FIG. Of course, the oil level varies depending on the temperature of the oil, on the geometric position of the transmission G, and on the centrifugal forces acting on the oil. The transmission G may also have a Figure 3a . The oil pump P is adapted to suck oil out of the oil sump SU and supply it to the hydraulic control unit HCU. To this end, the pump P is driven by two gears PX, PX2. The gears PX, PX2 form the drive elements of the oil pump P. The gear PX is driven by a gear connected to the torque converter housing TCG. The gear PX2 is connected to the drive shaft of the oil pump P. The hydraulic control unit HCU is adapted to supply the oil supplied by the pump P to the various hydraulic consumers of the transmission G, such as components of the wheelset RS, the torque converter TC, the lockup clutch WK, and the cooling device of the electric machine EM. The oil supplied in this way then flows back into the oil sump SU, thereby forming a closed oil circuit.

[0032] The cavity NR forms the wet space of the transmission G. A cooling device KV is provided for cooling the electric machine EM, which supplies cooling oil KF to the electric machine EM. The cooling oil KF flows downwards at the electric machine EM, so that heat energy is transferred from the electric machine EM to the cooling oil KF.

[0033] An oil guide housing LS is provided in the wet space NR and is fastened to the housing GG. The oil guide housing LS has an L-shaped cross section, wherein the L shape is formed by a first section LS1 and a second section LS2. The first section LS1 extends along the second end side TC2 of the torque converter housing TCG. The second section LS2 partially surrounds the circumferential surface of the torque converter housing TCG and the stator ST. Here, the oil guide housing LS only surrounds the region of the torque converter housing TCG and the stator ST that is at the bottom in the installed position.

[0034] The cooling oil KF flowing downward from the electric machine EM is partially collected on the inner surface of the oil guide housing LS. The inner surface of the oil guide housing LS is the surface facing the torque converter housing TCG. The remaining cooling oil KF flows directly back to the oil sump SU below the oil guide housing LS.

[0035] A gap C is provided between the inner surface of the oil guide housing LS and the torque converter housing TCG. Since the torque converter housing TCG can have a high rotation speed and the oil guide housing LS is fixed to prevent rotation, the oil in the gap C may emulsify the oil and cause the splash loss of the transmission G to increase.

[0036] Figure 3b A schematic cross-sectional view of a hybrid drive unit is shown, which is substantially similar to the cross-sectional view according to Figure 3a Refer to the diagram below. Figure 3a The only difference is the increased oil level, which is Figure 3b In the illustration of , the oil guide housing LS is arranged spatially above the lowest point of the oil guide housing LS. In a hybrid drive unit, such a high oil level may be present, for example, at a high operating temperature of the oil and (if present) when the oil reservoir is empty. Even at such an oil level, the oil guide housing LS helps to reduce splash losses, because due to the rotational speed of the torque converter housing TCG, more oil is conveyed from the inside of the oil guide housing LS than the cooling oil KF flowing downward from the oil sump SU or from the electric machine EM.

[0037] Figure 4 The basis for indicating the downhill position of the motor vehicle Figure 3a or Figure 3b Transmission G. Reference Figure 3a In the reference numerals Figure 4 , the oil level that occurs in the oil pan SU in the downhill position is shown in . In this position, more oil can be gathered in the gap C.

[0038] Figure 5 The following is shown during the period of severe deceleration of a motor vehicle: Figure 3a or Figure 3b Transmission G. Reference Figure 3a In the reference numerals Figure 5 The oil level that occurs in the oil pan SU during deceleration of a motor vehicle is shown in . In this position, a larger amount of oil can be collected in the gap C.

[0039] Once the transmission G is in a horizontal position again or the vehicle stops decelerating, the oil in the gap C can passively flow back to the oil sump SU through the L-shape of the oil guide housing LS. To accelerate this process, structural means can be provided, which are described below.

[0040] Figure 6 The oil guide housing LS is shown in a perspective view. The oil guide housing LS can be designed, for example, as a plastic shell and has three fastening points LSB on the housing GG for screwing. A shielding element LSA is provided on the section LS1 of the oil guide housing LS, which serves to shield the gear PX. An oil scraping edge LSX is formed on the second section LS2 of the oil guide housing LS. The torque converter housing TCG ( Figure 6 The oil in the gap C is transported in the direction of the scraping edge LSX by the rotation of the oil guide housing (not shown). The oil rebounds on the scraping edge LSX and flows back to the oil pan SU along the outer side of the oil guide housing LS. Figure 7 This process is shown more clearly in .

[0041] Figure 8 An alternative design of an oil guide housing LS is shown without an integrally formed oil scraping edge. Instead, an oil scraping edge GGX formed on the housing GG is provided. The oil scraping edge GGX may also be fastened to the housing GG.

[0042] Fig. 9 A further design possibility is shown with an oil guide housing LS. Figure 3a A portion of the transmission G shown in FIG. Figure 3a The oil guide housing LS now has an outflow channel LSK, through which the oil can flow away from the gap C to the oil sump SU. Such an outflow channel LSK can be provided in addition to or instead of the oil scraping edge LSX / GGX.

[0043] List of Reference Numerals

[0044] VM combustion engine

[0045] HY Hybrid Power Module

[0046] G Transmission

[0047] AN connecting shaft

[0048] GG Housing

[0049] GGX Scrape Edge

[0050] AG Differential

[0051] DW drive wheel

[0052] EM Electric Machine

[0053] ST Stator

[0054] RO rotors

[0055] KV Cooling Unit

[0056] KF Cooling Oil

[0057] TC Torque Converter

[0058] TCG Torque Converter Housing

[0059] TC1 First end side of the torque converter housing

[0060] TC2 Second end side of the torque converter housing

[0061] TR Turbine

[0062] PR pump impeller

[0063] LR Guide Wheel

[0064] F Freewheel

[0065] WK Lock-up Clutch

[0066] RS transmission wheel set

[0067] GW1 Input shaft

[0068] GW2 output shaft

[0069] HCU Hydraulic Control Unit

[0070] P Oil Pump

[0071] SU oil pan

[0072] Drive elements for PX, PX2 oil pumps

[0073] K0 Disengagement clutch

[0074] NR Wet Space

[0075] LS oil guide housing

[0076] LS1 First section of oil guide housing

[0077] LS2 Second section of oil guide housing

[0078] LSB fastening points

[0079] LSA Shielding Elements

[0080] LSX scraper edge

[0081] LSK outflow channel

Claims

1. A hybrid drive unit (HY, G) for a motor vehicle, wherein the hybrid drive unit (HY, G) has a housing (GG) in which a torque converter (TC) and an electric machine (EM) are accommodated, - wherein the electric machine (EM) and the torque converter (TC) are arranged directly next to each other in a common wet space (NR), whereby the electric machine (EM) is arranged at a first end side (TC1) of the torque converter housing (TCG), - wherein the rotor (RO) of the electric machine (EM) is connected to a torque converter housing (TCG) of the torque converter (TC), - an oil guide housing (LS) is provided which partially surrounds a section of the torque converter (TC), It is characterized in that The oil guide housing (LS) has an L-shaped cross section with a first section (LS1) and a second section (LS2), and the oil guide housing is arranged so that: the first section (LS1) partially surrounds the second end side (TC2) of the torque converter housing (TCG), and the second section (LS2) partially surrounds the circumferential surface of the torque converter housing (TCG).

2. The hybrid drive unit (HY, G) according to claim 1, characterized in that The oil guiding housing (LS) is arranged such that a second section (LS2) of the oil guiding housing (LS) partially surrounds a circumferential surface of the electric machine (EM).

3. The hybrid drive unit (HY, G) according to claim 2, characterized in that The rotor (RO) is arranged radially within a stator (ST) of the electric machine (EM), wherein that section of the electric machine (EM) which is surrounded by the oil guide housing (LS) is formed by a section of the stator (ST).

4. The hybrid drive unit (HY, G) according to claim 1, characterized in that The electric machine (EM) can be cooled by supplying cooling oil (KF), wherein the oil guide housing (LS) is designed and arranged such that a portion of the cooling oil (KF) flowing away from the electric machine (EM) is collected on an inner surface of the oil guide housing (LS).

5. The hybrid drive unit (HY, G) according to claim 4, characterized in that The oil guide housing (LS) surrounds only a part of the axial extension of the electric machine (EM), wherein the oil guide housing (LS) is designed and arranged in such a way that cooling oil (KF) flowing away from the electric machine (EM) is only partially collected on the inner surface of the oil guide housing (LS).

6. The hybrid drive unit (HY, G) according to claim 4, characterized in that The oil guide housing (LS) and the housing (GG) of the hybrid drive unit (HY, G) are designed and arranged so that the portion of the cooling oil (KF) flowing away from the electric machine (EM) that is not collected on the inner surface of the oil guide housing (LS) is guided to the oil sump (SU) of the hybrid drive unit (HY, G) spatially below the oil guide housing (LS).

7. The hybrid drive unit (HY, G) according to any one of claims 4 to 6, characterized in that A gap (C) is formed between an inner surface of the oil guide housing (LS) and a torque converter housing (TCG) of the torque converter (TC), wherein the oil guide housing (LS) is arranged so that the collected cooling oil (KF) can flow into the gap (C).

8. The hybrid drive unit (HY, G) according to claim 7, characterized in that Means are provided for discharging cooling oil (KF) present in the gap (C).

9. The hybrid drive unit (HY, G) according to claim 8, characterized in that The device is formed by an oil scraping edge (LSX) formed on the oil guide housing (LS).

10. The hybrid drive unit (HY, G) according to claim 8, characterized in that The device is formed by an oil scraping edge (GGX) formed or fastened on a housing (GG) of the hybrid drive unit (HY, G).

11. The hybrid drive unit (HY, G) according to claim 8, characterized in that The device is formed by an outflow channel (LSK) of the oil guide housing (LS).

12. The hybrid drive unit (HY, G) according to claim 1, characterized in that The oil guide housing (LS) is connected to the housing (GG) in a rotationally fixed manner.

13. The hybrid drive unit (HY, G) according to claim 1, characterized in that The oil guide housing (LS) has a shielding element (LSA) which partially shields a drive element (PX) of an oil pump (P) of the hybrid drive unit (HY, G).

14. The hybrid drive unit (HY, G) according to claim 1, characterized in that The oil guide housing (LS) is arranged such that, in a horizontally oriented installation position of the hybrid drive unit (HY, G), the oil level in the hybrid drive unit (HY, G) is above a lowest point of the oil guide housing (LS).

15. The hybrid drive unit (HY, G) according to claim 1, characterized in that The hybrid drive unit is composed of a transmission (G) or a hybrid module (HY).

16. A powertrain for a motor vehicle, characterized in that A hybrid drive unit (HY, G) according to any one of claims 1 to 15.

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