Hybrid powertrain

Abstract

A hybrid power transmission and a method for assembling the hybrid power transmission of the type described herein, the hybrid power transmission comprising an electric motor having an external stator (1) and an internal rotor shaft (2), wherein the hybrid power transmission further comprises a transmission element (3) located in a transmission housing (4) and a clutch (5) located in a clutch housing (6), wherein the stator (1) is secured in the transmission housing (4), wherein the rotor shaft (2) has a pinion (7) at a first end that meshes with an intermediate gear (8) of the transmission element (3 ... The sub-shaft (2) is mounted in the region of the first end of the rotor shaft (2) and the region of the second end of the rotor shaft at the opposite position by means of a first bearing (9) and a second bearing (10), wherein an intermediate plate (11) fastened to the stator (1) is arranged axially in the region of the first end of the rotor shaft (2), wherein the second bearing (10) for mounting the second end of the rotor shaft (2) is directly fixed in the clutch housing (6), and the first bearing (9) for mounting the first end of the rotor shaft (2) is fixed to the transmission housing (4) or fixed to the intermediate plate (11).

Description

Technical Field

[0001] The present invention relates to a hybrid power transmission including an electric motor and a transmission component, and to a method for assembling a hybrid power transmission of the type described herein. Background Technology

[0002] Hybrid electric vehicles, also known simply as hybrid vehicles, are now well-known and use at least one electric motor and an additional drive, typically an internal combustion engine, to propel the vehicle. In the case of a parallel hybrid drive, the electric motor and the internal combustion engine can simultaneously transmit their drive torque to the drivetrain. Different architectures are known for the arrangement of the electric motor, internal combustion engine, and drivetrain in parallel hybrid vehicles. In the so-called P2.5 arrangement, the electric motor is typically located in a dual-clutch drive on the input shaft of the sub-drive.

[0003] The motor that connects to a partial transmission component according to application P2.5 and is mounted in the transmission component has so far been used as a separate pre-assembled module, wherein the motor module includes not only the rotor and stator, but also two end covers for mounting the rotor shaft.

[0004] If the free end of the rotor shaft has a pinion, the mounting of the rotor shaft in the end cover typically arranges the pinion axially on the "rear" or "outer" bearing on that side of the rotor shaft (so-called "overhang mounting").

[0005] The entire pre-assembled motor module can then be screwed into the transmission housing, for example, by screwing the entire pre-assembled motor module into the transmission housing using screw attachment bosses on the end caps.

[0006] In this configuration, the motor module must have two end covers connected to the stator to accommodate the rotor shaft bearings. This results in additional structural space requirements in both the radial and axial directions of the motor module. Furthermore, the individual module becomes heavier due to the weight of the end covers. Because of the suspended mounting of the motor rotor, the bearings at the free ends of the rotor shaft must be larger than if the bearings were located "behind" the pinion. Additionally, due to the suspended mounting, the pinion tilts to a greater extent during operation under load compared to if the bearings were located "behind" the pinion. This tilt leads to undesirable acoustic salience (NVH – noise, vibration, and harshness). The end covers, along with the similarly larger bearings, also incur higher costs. Summary of the Invention

[0007] The objective of this invention is to improve upon the type of hybrid powertrain by addressing at least some of the aforementioned disadvantages, and in particular to specify a hybrid powertrain with smaller structural space requirements, lighter weight, and lower cost. Furthermore, it seeks to specify an efficient and inexpensive method for assembling such a hybrid powertrain suitable for mass production.

[0008] The objective is achieved by means of a hybrid power transmission including an electric motor, wherein the electric motor has an external stator and an internal rotor shaft, wherein the hybrid power transmission also includes a transmission element located in a transmission housing and a clutch located in a clutch housing, wherein the stator is fastened in the transmission housing or the clutch housing, wherein the rotor shaft has a pinion at a first end that meshes with an intermediate gear of the transmission element, wherein the rotor shaft is mounted in a region at the first end of the rotor shaft and in a region at the opposite second end of the rotor shaft, wherein an intermediate plate is axially arranged in the region at the first end of the rotor shaft, wherein the stator is fastened to the intermediate plate, wherein a second bearing for mounting the second end of the rotor shaft is directly fixed in the clutch housing, and a first bearing for mounting the first end of the rotor shaft is directly fixed to the transmission housing or fixed to the intermediate plate.

[0009] According to the present invention, a motor module without end covers, capable of being inserted into a transmission component, is produced. The rotor shaft is mounted at two bearings, wherein one bearing, particularly the second bearing, located at the non-pinion-carrying end of the rotor shaft, is directly fixed, i.e., rotatably fastened, to the housing component of the hybrid power transmission, particularly in the clutch housing. The other bearing, i.e., the first bearing, is either also directly fastened to the housing, particularly in the transmission housing, or fastened to an intermediate plate, which itself serves to fasten the fastener and is preferably also threaded into the transmission housing. The intermediate plate is preferably a generally circular plate, standing vertically relative to the rotor shaft and preferably having a similar circular recess on its inner side through which the motor shaft extends. It is also preferred that a short shaft is integrally formed on the intermediate plate, or rotatably fastened, on which an intermediate gear meshing with the pinion of the rotor shaft is mounted.

[0010] Therefore, the rotor shaft is directly mounted in the housing of the hybrid powertrain at at least one or both ends. Thus, at least one end cover can be omitted. The intermediate plate can be equipped with various additional components and can have at least a short shaft for mounting the intermediate gear, and is therefore used for various purposes, such as also mounting the rotor shaft, rotor position sensor, and / or rotor grounding ring.

[0011] Therefore, the motor is fully integrated into the transmission component, preferably in a P2.5 architecture. This makes it possible to have a method for mounting the motor into the transmission component, suitable for mass production, in which the motor rotor is directly mounted in the two housing halves, and the rotor and stator do not come into contact in a damaging manner during the mounting process.

[0012] With the help of this mounting without end guards, cost savings can be achieved due to the omission or removal of components, shortening of tolerance chains, optimization of structural space, weight reduction, optimization of gear tilting under load, and thus NVH optimization, as well as the potential for size reduction of rotor bearing arrangement.

[0013] The terms "transmission housing" and "clutch housing" can refer to two parts of a common housing, particularly two halves.

[0014] The pinion at the first end of the rotor shaft is preferably axially located between the first bearing and the second bearing, such that the first bearing is located outside the pinion on the rotor shaft.

[0015] According to one embodiment, a clamping ring is axially arranged in the region at the second end of the rotor shaft, wherein the stator is clamped between the intermediate plate and the clamping ring, preferably by means of tension bolts.

[0016] According to another embodiment, the stator, particularly the stator laminations, may have axial screw attachment bosses in the region of the second end of the rotor shaft, such that the stator is clamped between the intermediate plate and the screw attachment bosses, preferably by means of tension bolt support.

[0017] The method for assembling a hybrid power transmission of the type described above according to the invention comprises the following steps: first, pre-assembling a rotor module comprising at least a rotor shaft and a rotor lamination core, and pre-assembling a stator module comprising at least one stator lamination core having stator windings; placing the rotor module and stator module axially on a workpiece carrier; and mounting the rotor module and stator module one inside the other in a non-contact manner, such that the rotor module and stator module preferably do not contact each other, wherein the rotor is preferably rotatably and fixedly received on the workpiece carrier; mounting an intermediate plate, preferably comprising a short shaft for mounting an intermediate gear, on the stator; assembling the rotor module and stator module mounted on the workpiece carrier together with a transmission component; placing the transmission component housing on top of the transmission component; and connecting the clutch housing to the transmission component housing.

[0018] Preferably, before placing the rotor module and stator module on the workpiece carrier in the axial direction and fitting the rotor module and stator module into the other in a non-contact manner, the rotor module and stator module have been temporarily fitted into the other so that the rotor shaft can rotate, and at least one test, such as a rotation test, is performed to select defective parts.

[0019] After the transmission housing has been placed on top of the transmission component, the intermediate plate is preferably screwed onto the transmission housing.

[0020] After the intermediate plate, including the short shaft for mounting the intermediate gear, is mounted on the stator, and preferably before the rotor module and stator module mounted on the workpiece carrier are assembled with the transmission component, the intermediate gear and the bearing arrangement structure of the intermediate gear are preferably fastened to the short shaft.

[0021] It is preferable to secure the first bearing for mounting the first end of the rotor shaft to the rotor shaft after the intermediate gear has been secured to the short shaft, and preferably before assembling the rotor module and stator module mounted on the workpiece carrier with the transmission components. Alternatively, the first bearing may have already been secured in the intermediate plate.

[0022] Before connecting the clutch housing to the transmission housing, preferably after the transmission housing has been placed on the transmission, the clamping ring can be axially attached to the stator in the region at the second end of the rotor shaft, wherein the stator is clamped between the intermediate plate and the clamping ring. This is particularly preferred if the stator is supported between the intermediate plate and the clamping ring by means of multiple tension bolts, or between screw attachment bosses of the intermediate plate and the stator.

[0023] Other advantageous steps of the assembly method are specified in the description of the accompanying drawings.

[0024] Therefore, the present invention describes a method for assembling a hybrid powertrain, which enables the motor to be directly mounted in the clutch housing (Variation 1) or in the clutch housing and transmission housing (Variation 2) by means of one bearing (second bearing) (hereinafter referred to as Variation 1) or two bearings (first bearing and second bearing) (hereinafter referred to as Variation 2). Thus, end caps can be omitted or made lighter and more space-saving, allowing the first bearing located in the transmission housing to be directly positioned "rear" of the pinion (Variation 2). Positioning the first bearing at the rear of the pinion (Variation 2) minimizes pinion tilt under load, which has a positive impact on the bearing size and noise characteristics (NVH) of the first bearing, as well as cost savings (Variation 1 and Variation 2). Attached Figure Description

[0025] The invention will now be described by way of example with reference to the accompanying drawings.

[0026] Figure 1 This is a three-dimensional illustration of the motor of the hybrid power transmission device according to the present invention, viewed from the second end of the rotor shaft.

[0027] Figure 2 According to the observation from the first end of the rotor shaft. Figure 1 A 3D illustration of the motor in a hybrid powertrain.

[0028] Figure 3 It is based on Figure 1 A cross-sectional view of the motor of the hybrid powertrain from the side view.

[0029] Figure 4 It is based on Figure 1 A detailed cross-sectional view of the hybrid power transmission device of the electric motor according to the present invention.

[0030] Figure 5 It is according to the invention for assembly according to Figure 4 A schematic diagram of the steps of a method for a hybrid power transmission device. Detailed Implementation

[0031] Figures 1 to 3 The illustration shows the motor of the hybrid power transmission according to the present invention—in Figure 1 The middle view is taken from the side of the second bearing 10. Figure 2 The middle view is taken from the side of the first bearing 9, and in Figure 3 The middle view is a cross-sectional view from the side.

[0032] The motor includes an external stator 1 and an internally rotatable rotor shaft 2. Motors of this type (see...) Figure 4 The hybrid powertrain includes a transmission 3 located in a transmission housing 4 and a clutch 5 located in a clutch housing 6. The stator 1 is then fastened to the transmission housing 4.

[0033] The motor and transmission components 3 are arranged in a P2.5 architecture.

[0034] The rotor shaft 2 has a pinion 7 at its first end. Figure 2 and Figure 3 The pinion 7 meshes with the intermediate gear 8 of the transmission component 3. Figure 4 and Figure 3 The rotor shaft 2 is mounted in the region of the first end of the rotor shaft 2 and the region of the second end of the rotor shaft 2 at the opposite position by means of the first bearing 9 and the second bearing 10.

[0035] The intermediate plate 11, which is fastened to the stator 1, is axially arranged in the region at the first end of the rotor shaft 2. Figure 2 ).

[0036] The second bearing 10, used for mounting the second end of the rotor shaft 2, is directly fixed in the clutch housing 6, and the first bearing 9, used for mounting the first end of the rotor shaft 2, is fixed to the transmission housing 4. Figure 4 It can be fixed to the intermediate plate 11. The intermediate plate 11 is threaded into the transmission housing 4.

[0037] The intermediate gear 8 is mounted on the short shaft 12, wherein the short shaft 12 is formed on the intermediate plate 11. Figure 2 and Figure 3 ).

[0038] exist Figure 2 and Figure 3 The figure shows that the pinion 7 is located axially between the first bearing 9 and the second bearing 10 and at the first end of the rotor shaft 2, such that the first bearing 9 is located outside the pinion 7 of the rotor shaft 2.

[0039] The static part of the rotary transformer 21 and the AC phase terminals 22 of the motor are also fastened to the intermediate plate 11. The intermediate plate 11 is screwed to the transmission housing 4 by means of fastening screws 23.

[0040] Figure 1 The stator 1 is shown clamped between an intermediate plate 11 and screw attachment bosses 19 of the stator laminations, as the intermediate plate 11 and screw attachment bosses 19 are supported by a plurality of circumferentially distributed tension bolts 14, specifically screws. The tension bolts 14 extend through the clamping rings or screw attachment bosses 19 of the stator 1 and into fastening points on the intermediate plate 11, which are respectively assigned to the screw attachment bosses 19. The intermediate plate 11 also has fastening screws 23 for threading the intermediate plate 11 to the transmission housing 4.

[0041] The winding head 18 of stator 1 is in Figure 1 It can also be seen at the second end of the rotor shaft.

[0042] Figure 5 The illustration schematically depicts the assembly according to the invention. Figures 1 to 4 The steps of the method for a hybrid power transmission device.

[0043] The steps of this method are preferably performed in the time sequence shown in the figure.

[0044] Step 1, a): The initial state of the motor is as follows:

[0045] A pre-assembled rotor module 15 includes:

[0046] - Rotor shaft 2, wherein the pinion 7 may have been cut into the rotor shaft.

[0047] - Rotor lamination core, which can be conventionally fastened to the shaft by means of an interference fit.

[0048] - In the case of permanent magnet synchronous machines, permanent magnets are included, which can be fastened to or within the rotor lamination core.

[0049] - The rotating part of the rotary transformer (“target”), which can be fastened to a shaft.

[0050] -Optional second bearing 10.

[0051] A pre-assembled stator module 16 includes:

[0052] -Stator laminated core,

[0053] - Stator winding, which is embedded in the stator lamination core, wherein conventional method steps for producing stator windings have been performed (forming the winding head, potting with impregnating resin, crimping phase terminals, etc.).

[0054] -Temperature sensor and low-voltage connection.

[0055] The proposed method includes the following steps:

[0056] Step 2, b): Temporarily mount the pre-assembled modules 15 and 16 in a non-contact manner, one inside the other, wherein the rotor can be held at both ends, for example by means of a so-called centering pin, so that the rotor can rotate.

[0057] The pre-assembled modules 15 and 16 can undergo a series of tests, including rotor rotation (so-called dynamic motor testing), to identify and remove faulty parts from further assembly and / or to determine important machine parameters that are prone to change.

[0058] Step 3, c): After testing, the two pre-assembled modules 15 and 16 are first separated again and then re-paired in a non-contact manner on the workpiece carrier 17, wherein the rotor is non-rotatable in this case. The "combination" of rotor module 15 and stator module 16 occurs here as follows:

[0059] - The stator module 16 is mounted on the workpiece carrier 17, which holds the vertically standing stator 1 and centers the vertically standing stator 1.

[0060] - The workpiece carrier 17 includes a guide in which an optional axially movable centering pin is mounted.

[0061] - The rotor module 15 is vertically mounted axially onto a centering pin, which protrudes into the inner contour of the rotor's hollow shaft. Here, the rotor shaft 2 is designed as a hollow shaft. This allows for the advantageous mounting of the rotor and stator without dynamic contact between them during the process, which could potentially damage one of the components.

[0062] Step 4, d): The rotor module 15 and the stator module 16 are mounted on the workpiece carrier 17 in a non-contact manner.

[0063] Step 5, e): Install the intermediate plate 11 onto the stator 1. The intermediate plate 11 includes:

[0064] -Short shaft 12, short shaft 12 is used to accommodate the intermediate gear bearing arrangement structure.

[0065] - Receiving part, which is used for the stator of rotary transformer 21.

[0066] Depending on the selected variant (1 or 2), the intermediate plate 11 may also include a bearing housing for the first bearing 9 (Variation 1). Figure 4 The illustration shows variant 2, in which the installation is achieved in the transmission housing 4.

[0067] Step 6, f): Secure the intermediate gear 8, along with its bearing arrangement, to the short shaft 12.

[0068] Step 7, g): Install the first bearing 9 (in the case of variant 2) on the "rear" (or outside) of the pinion 7.

[0069] Step 8, h): Secure modules 15 and 16, which are pre-assembled on the workpiece carrier 17, to the transmission workpiece carrier. The pre-assembled gear set of the transmission 3 is present on the transmission workpiece carrier, and the motor and the gear chain of the transmission 3 are engaged with each other.

[0070] Step 9: Manually place the transmission housing 4 onto the gear set, wherein, among other things, the first bearing 9 of the motor is received in the transmission housing 4 (in variant 2).

[0071] Step 10, i): Rotate the clutch housing 6, which contains the gear set and motor modules 15, 16, so that the open housing half points vertically upward. The workpiece carrier 17 of the motor assemblies 15, 16 remains fastened to the stator 1 in this case and rotates together with it.

[0072] Step 11, j): Thread the intermediate plate 11 into the transmission housing 4.

[0073] For the further process, whether or not variant 1 or variant 2 is implemented, there are now two conceivable methods, referred to below as I or II:

[0074] Method I ( Figure 5 (As shown in the illustration):

[0075] - Remove the workpiece carrier 17 with the centering pin. Since the second bearing 10 has not yet been installed in the clutch housing 6, the rotor will abut against the stator 1 due to magnetic force. However, this is not important because it occurs in a quasi-steady state (there is no further relative motion after the abutment occurs).

[0076] Method II:

[0077] - The rotor is held by a centering pin, which is inserted into the rotor from below through the hole, via a hole present in a suitable location in the transmission housing 4 under any circumstances. Figure 5 In the image (j), the position and direction of the insertion of the second centering pin are indicated by an upward-pointing vertical arrow.

[0078] Both methods share the following optional steps:

[0079] On the second side of the rotor shaft 2, a clamping ring including four screw attachment bosses 19 is attached to the outer diameter of the stator 1. By means of these screw attachment bosses 19 of the clamping ring, or the screw attachment bosses 19 directly located on the stator 1, the stator 1 is clamped between the screw attachment bosses 19 and the intermediate plate 11.

[0080] Regarding another method, a distinction is made again between Method I and Method II:

[0081] Method I:

[0082] A hole is provided at an appropriate location in the clutch housing 6 (see...) Figure 5 The circular mark in step k). When the clutch housing 6 descends onto the transmission housing 4 with the gear set to close the transmission (in Figure 5 The image I illustrates the station used for this purpose, where the center pin can again protrude through the hole into the rotor shaft 2, releasing the rotor shaft 2 from the stator 1 and subsequently holding the rotor shaft in a defined position while connecting the clutch housing 6 to the transmission housing 4.

[0083] The center pin is then pulled out, and the opening in the clutch housing 6 is closed.

[0084] Method II:

[0085] Since the lower centering pin centers the rotor in a defined position, the opening in the clutch housing 6 is no longer needed during the fitting of the clutch housing 6 to the transmission housing 4.

[0086] In both methods and variations, the clutch housing 6 receives the second bearing 10 (see [reference]). Figure 4 ).

[0087] List of reference numerals

[0088] 1. Stator

[0089] 2. Rotor shaft

[0090] 3. Transmission components

[0091] 4. Transmission component housing

[0092] 5. Clutch

[0093] 6. Clutch housing

[0094] 7 small gears

[0095] 8. Intermediate gear

[0096] 9 First bearing

[0097] 10 Second Bearing

[0098] 11. Intermediate Plate

[0099] 12 Short Axis

[0100] 14 tension bolts

[0101] 15 Rotor Modules

[0102] 16 Stator Modules

[0103] 17. Workpiece support component

[0104] 18 Winding head

[0105] 19. Screw attachment boss

[0106] 20 Fastening screws

[0107] 21 Rotary Transformer

[0108] 22 AC phase terminals

[0109] 23 Fastening screws

Claims

1. A method for assembling a hybrid powertrain, the hybrid powertrain comprising an electric motor, wherein, The motor has an external stator (1) and an internal rotor shaft (2), wherein the hybrid power transmission further includes a transmission element (3) located in a transmission housing (4) and a clutch (5) located in a clutch housing (6), wherein the stator (1) is fastened in the transmission housing (4) or the clutch housing (6), wherein the rotor shaft (2) has a pinion (7) at a first end that meshes with an intermediate gear (8) of the transmission element (3), wherein the rotor shaft (2) is mounted in the region of the first end of the rotor shaft (2) and the region of the second end of the rotor shaft (2) at the opposite position by means of a first bearing (9) and a second bearing (10). The feature is that an intermediate plate (11) is axially arranged in the region of the first end of the rotor shaft (2), wherein the stator (1) is fastened to the intermediate plate (11), wherein the second bearing (10) for mounting the second end of the rotor shaft (2) is directly fixed in the clutch housing (6), and the first bearing (9) for mounting the first end of the rotor shaft (2) is fixed to the transmission housing (4) or fixed to the intermediate plate (11), and The method includes: firstly, pre-assembling a rotor module (15) comprising at least the rotor shaft (2), rotor lamination core, and the second bearing (10), wherein the rotor shaft (2) has the pinion (7) at a first end; and pre-assembling a stator module (16) comprising at least one stator lamination core having stator windings, wherein the rotor module (15) and the stator module (16) are placed axially on a workpiece carrier (17), and the rotor module (15) and the stator module (10) are... 6) In a non-contact manner, one component is fitted inside the other, wherein the intermediate plate (11), including the short shaft (12) for mounting the intermediate gear (8), is mounted on the stator (1), wherein the rotor module (15) and the stator module (16), fitted on the workpiece carrier (17), are assembled with the transmission component (3), wherein the transmission component housing (4) is placed on the transmission component (3), and wherein the clutch housing (6) is connected to the transmission component housing (4), and thereby After the intermediate plate (11), including the short shaft (12) for mounting the intermediate gear (8), is mounted on the stator (1), and before the rotor module (15) and the stator module (16) mounted on the workpiece carrier (17) are assembled with the transmission member (3), the intermediate gear (8) is fastened to the short shaft (12). Before assembling the rotor module (15) and the stator module (16) mounted on the workpiece carrier (17) with the transmission component (3), after the intermediate gear (8) has been fastened to the short shaft (12), the first bearing (9) for mounting the first end of the rotor shaft (2) is fastened to the rotor shaft (2), or the first bearing (9) has been fastened in the intermediate plate (11), and thereby After placing the transmission housing (4) on the transmission (3) and before connecting the clutch housing (6) to the transmission housing (4), the workpiece carrier (17) is removed.

2. The method according to claim 1, It is characterized in that The pinion (7) is axially located between the first bearing (9) and the second bearing (10) and at the first end of the rotor shaft (2), such that the first bearing (9) is located outside the pinion (7) of the rotor shaft (2).

3. The method according to claim 1, Its features are, A clamping ring is axially arranged in the region of the second end of the rotor shaft (2), wherein the stator (1) is clamped between the intermediate plate (11) and the clamping ring, and is clamped between the intermediate plate (11) and the clamping ring by means of a tension bolt (14), or wherein the stator (1) has an axially arranged screw attachment boss (19) in the region of the second end of the rotor shaft (2), such that the stator (1) is clamped between the intermediate plate (11) and the screw attachment boss (19), and is clamped between the intermediate plate (11) and the screw attachment boss (19) by means of a tension bolt (14).

4. The method according to claim 1, It is characterized in that Before placing the rotor module (15) and the stator module (16) axially on the workpiece carrier (17) and fitting the rotor module (15) and the stator module (16) into the other in a non-contact manner, the rotor module (15) and the stator module (16) have been temporarily fitted into the other so that the rotor shaft (2) can rotate and at least one rotation test is performed to select defective parts.

5. The method according to claim 1, It is characterized in that After the transmission housing (4) has been placed on the transmission (3), the intermediate plate (11) is screwed onto the transmission housing (4).

6. The method according to claim 1, Its features are, Before connecting the clutch housing (6) to the transmission housing (4), after the transmission housing (4) has been placed on the transmission (3), the clamping ring is axially attached to the stator (1) in the region of the second end of the rotor shaft (2), wherein the stator (1) is clamped between the intermediate plate (11) and the clamping ring, and the stator (1) is clamped between the intermediate plate (11) and the clamping ring by means of tension bolts (14).

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