DE102020104726A1 - Bearing element, connecting plate and drive unit with such a bearing element - Google Patents

Abstract

The invention relates to a bearing element (15) for mounting a motor shaft (17) of an electric drive motor (1) and a rotating component (18, 31) of a gear unit (3) connected to the electric drive motor (1). Provision is made for a first bearing seat (35) for mounting the rotating component (18, 31) of the gear unit (3) and a second bearing seat (36) for the rotatable mounting of the motor shaft ( The invention also relates to a connecting plate (4) for connecting an electric drive motor (1) to a gear (3) with such a bearing element (15) and to a drive unit with an electric drive motor (1) and a gear (3) ), the electric drive motor (1) and the gear (3) being connected to one another via such a bearing element (15).

Description

The invention relates to a bearing element for mounting a drive shaft and a rotating component of a gearbox and a connecting plate for connecting an electric drive motor to a gearbox with such a bearing element and a drive unit with an electric drive motor and a gearbox, which are connected to one another via such a bearing element, according to the preamble of the independent claims.

Different drive concepts are known for electrically driven motor vehicles. A preferred drive concept has, analogously to a drive concept for a motor vehicle with an internal combustion engine, a central electric drive motor which is connected to the driven wheels of the motor vehicle via a drive train. A gear, in particular a reduction gear, is arranged between the electric drive motor and the driven wheels of the motor vehicle in order to reduce the speed of the electric drive motor to the wheel speed of the driven wheels and to increase the drive torque accordingly. Furthermore, a differential is provided in such a drive concept in order to distribute the drive torque of the electric drive motor to the driven wheels and to enable a different wheel speed between the driven wheel on the inside of the bend and the driven wheel on the outside of the bend, in particular when the motor vehicle is cornering.

In order to connect the motor shaft of the electric drive motor to the transmission, couplings are known which transmit the torque of the electric drive motor to the transmission. In contrast to a drive train with an internal combustion engine, it is not necessary, at least in the case of a non-shiftable transmission, to separate the electric drive motor from the transmission. A transmission element is used here, which takes up the motor shaft of the electric drive motor and transmits the drive torque to a transmission input shaft. In order to increase the rigidity of the drive train, at least one of the shafts can be rotatably mounted on the transmission element.

From the DE 10 2014 118 553 A1 a rolling bearing for a vehicle transmission is known which has an inner ring, an outer ring and a plurality of rolling elements arranged between the inner ring and the outer ring. In this case, a damping layer consisting of a vibration-damping material is formed on the roller bearing, which is arranged in the outer ring, the inner ring or in an adapter ring surrounding the roller bearing on its outer circumference, that the outer ring, the inner ring or the adapter ring is separated from each other by the damping layer independent parts is divided.

The EP 2 659 573 B1 discloses a bearing unit for supporting a shaft which connects an electric drive motor to a gearbox. The shaft is rotatably mounted in a housing of the electric drive motor. The bearing unit comprises a receiving body for receiving a roller bearing, the receiving body being received in the housing of the electric drive motor and enabling the shaft to be rotatably supported.

The disadvantage of the known solutions, however, is that the isolation of the transmission components in the power flow leads to a reduction in rigidity. This can increase the load on the gears in the transmission, which reduces the durability and can increase the excitation of vibrations in the transmission. In addition, due to the elasticity in the bearing area, misalignments can occur, which lead to increased friction and thus to losses in the drive train.

The object of the invention is to connect the motor shaft and the transmission to one another in a drive train of a motor vehicle which connects an electric drive motor to a transmission of the motor vehicle and, in particular, to minimize deviations in the coaxiality and associated losses.

According to the invention, this object is achieved by a bearing element for mounting a motor shaft of an electric drive motor and a rotating component of a transmission connected to the electric drive motor. It is provided that a first bearing seat for supporting the rotating component of the transmission and a second bearing seat for rotatably supporting the motor shaft are formed on a radially inner lateral surface of the bearing element. As a result, both the motor shaft and the transmission input shaft or a component connected to the transmission input shaft or a component arranged on the transmission input shaft can be supported in the bearing element. By accommodating both shafts in the bearing element, a high degree of accuracy with regard to the coaxiality of the shafts can be achieved, as a result of which transmission losses can be minimized.

The features listed in the dependent claims enable advantageous improvements and further developments of the im independent claim listed connecting plate possible.

In a preferred embodiment of the bearing element it is provided that the bearing element has a receiving section on a radially outer lateral surface for receiving the bearing element in a housing or a connecting plate. This enables a simple non-positive connection to be established between the bearing element and the housing or the connecting plate. It is preferably provided that the bearing element is pressed into a metallic base support of the connecting plate or into a housing of the electric drive motor or the gearbox.

It is particularly preferred if the receiving section is located in the axial direction between the first bearing seat and the second bearing seat. As a result, the overall length of the bearing element can be kept short in the axial direction. Furthermore, by accommodating the bearing element in the area of its center of gravity, it can be prevented that the bearing element exerts a strong bending moment on the housing or the connecting plate, so that the load on the housing or the connecting plate can be reduced. As a result, the housing or the connecting plate can be designed with a smaller wall thickness, whereby the weight can be reduced.

In an advantageous embodiment of the bearing element, it is provided that the bearing element has a contact section on which a sensor, in particular an acceleration sensor or a temperature sensor, for monitoring the bearing element can be received. The function of the bearing can be checked or optimized by means of a sensor arranged on the bearing element. For example, speed ranges with increased vibration excitation can be avoided by appropriate regulation of the electric drive motor, or appropriate cooling measures can be initiated for the bearing in order to ensure improved heat dissipation.

It is particularly preferred if the contact section for the sensor is formed on an outer jacket surface of the bearing element. The vibrations in the drive train can be detected by an acceleration sensor, whereby critical excitation states with regard to the noise development can be recognized and reduced again by a corresponding control of the electric drive motor. It can also be helpful to control the electric drive motor to know a temperature of the drive shaft. Furthermore, the temperature of the bearing element is directly related to the power loss in the drive train, so that increased power loss can be recognized and appropriate measures, in particular additional cooling or lubrication measures, can be initiated in the drive train to minimize friction.

In an advantageous embodiment of the bearing element it is provided that the bearing element is designed as a composite hub. A composite hub is to be understood as meaning a hub composed of a composite of several different materials, in particular a combination of a metallic material and a polymer material. A composite hub can reduce the weight of the bearing element. Furthermore, a composite hub can combine the positive properties of different materials, so that the high mechanical rigidity of a metallic or ceramic material can be combined with the good vibration damping of a polymer material.

It is particularly preferred if the composite hub has a metallic base body and an area made of a polymer material and formed onto the metallic base body. Such a composite hub can be produced simply and inexpensively, wherein the area made of the polymer material can be molded onto the metallic base body, in particular by means of an injection molding process.

According to the invention, a connecting plate for connecting an electric drive motor to a transmission is proposed, the connecting plate having at least one bearing opening for a shaft to pass through. The connecting plate has a base support and a damping material connected to the base support, such a bearing element being received in the at least one bearing opening of the base support.

In a preferred embodiment of the connecting plate it is provided that the connecting plate has a first bearing opening and a second bearing opening for mounting axially parallel shafts. Thus, in addition to the motor shaft or the transmission input shaft, a further shaft can be supported in the connecting plate. This can in particular be an axle shaft for connecting the transmission to a driven wheel of a motor vehicle.

In an advantageous embodiment of the connecting plate it is provided that the connecting plate comprises a sensor, in particular an acceleration sensor or a temperature sensor, the sensor resting against the bearing element or an end section of the base support facing the bearing element. Through a Acceleration sensor, the vibrations in the drive train can be detected, whereby critical excitation states with regard to the noise development can be recognized and reduced again by a corresponding control of the electric drive motor. It can also be helpful to control the electric drive motor to know a temperature of the drive shaft.

Another aspect of the invention relates to a drive unit with an electric drive motor and a gear, the electric drive motor and the gear being connected to one another via such a connecting plate. Such a connecting plate enables efficient vibration damping between the electric drive motor and the transmission. In particular, a transmission chain for the transmission of structure-borne noise can be interrupted, so that the development of noise can be minimized. As an alternative or in addition, components that are excited to vibrate can be calmed by the damping material, which minimizes the development of noise.

In a preferred embodiment of the drive unit it is provided that a motor shaft of the electric drive motor is rotatably mounted in the bearing element. This enables the motor shaft to be supported, whereby the vibrations that occur do not contribute directly to the excitation of the housing of the electric drive motor or the gear housing. The transmission path for the development of noise can thus be interrupted, which minimizes the operating noise of the drive unit.

According to an advantageous further development of the drive unit, it is provided that the motor shaft is arranged concentrically to a transmission input shaft, an end section of the motor shaft being received in the transmission input shaft, with a carrier element, in particular a planet carrier of a planetary gear, which is rotatable in the bearing element, being arranged on the transmission input shaft is stored. As a result, a compact and optimized mounting of the motor shaft and the transmission input shaft or the carrier element can be realized, in particular the motor shaft and the transmission input shaft or the motor shaft and the carrier element can be centered with respect to one another by the bearing element, whereby the losses in the drive train can be minimized.

In a preferred embodiment of the bearing element it is provided that a first bearing seat and a second bearing seat are formed on a radially inner lateral surface of the bearing element. As a result, both the motor shaft and the transmission input shaft or a component connected to the transmission input shaft or a component arranged on the transmission input shaft can be supported in the bearing element. By accommodating both shafts in the bearing element, a high degree of accuracy with regard to the coaxiality of the shafts can be achieved, as a result of which transmission losses can be minimized.

The various embodiments of the invention mentioned in this application can advantageously be combined with one another, unless stated otherwise in the individual case.

• 1: eine aus dem Stand der Technik bekannte Antriebseinheit mit einem elektrischen Antriebsmotor und einem Getriebe;
• 2: ein Ausführungsbeispiel einer Antriebseinheit mit einem elektrischen Antriebsmotor und einem Getriebe, wobei der elektrische Antriebsmotor und das Getriebe durch eine erfindungsgemäße Verbindungsplatte verbunden sind;
• 3: eine Ansicht einer erfindungsgemäßen Verbindungsplatte von der Getriebeseite;
• 4: eine Ansicht einer erfindungsgemäßen Verbindungsplatte von der Seite des elektrischen Antriebsmotors; und
• 5: ein Lagerelement zur Lagerung der Motorwelle und der Getriebeeingangswelle, welches in einer Öffnung der Verbindungsplatte angeordnet ist.

The invention is explained below on the basis of preferred embodiments with reference to the accompanying figures. The same components or components with the same function are identified with the same reference symbols. Show:

• 1 : a drive unit known from the prior art with an electric drive motor and a gearbox;
• 2 : an embodiment of a drive unit with an electric drive motor and a gear, wherein the electric drive motor and the gear are connected by a connecting plate according to the invention;
• 3 : a view of a connecting plate according to the invention from the transmission side;
• 4th : a view of a connecting plate according to the invention from the side of the electric drive motor; and
• 5 : a bearing element for bearing the motor shaft and the transmission input shaft, which is arranged in an opening in the connecting plate.

1 shows a drive unit known from the prior art with an electric drive motor 1 and a gearbox 3 . In one housing 2 of the electric drive motor 1 is a motor shaft 17th arranged, which is coaxial with a transmission input shaft 18th of the transmission 3 runs and the drive torque of the electric drive motor 1 on the gearbox 3 transmits. There is a gear housing 14th of the transmission 3 directly on the housing 2 of the electric drive motor 1 attached. The transmission input shaft 18th stands on a toothed section 30th with a gear 29 , in particular with a planetary gear of a planetary gear in engagement, which on a carrier element 31 is stored. The transmission input shaft 18th is through a roller bearing 32 rotatable in the carrier element 31 stored. The motor shaft 17th and the extension of the motor shaft 17th transmission input shaft arranged coaxially with this 18th are also called the first wave 21 designated. Axially parallel to this first wave 21 is a second wave 22nd arranged, which with a first shaft segment 19th in the case 2 of the electric drive motor 1 and with a second shaft segment in the gear housing 14th runs. This second wave 22nd can be rotated in the corresponding housings by means of two roller bearings 2 , 14th stored.

In 2 is a preferred embodiment for a drive unit according to the invention with an electric drive motor 1 and a gearbox 3 shown in a schematic sectional drawing, which by a connecting plate according to the invention 4th are connected to each other. The electric drive motor 1 includes a housing 2 and a motor shaft 17th . In one housing 2 of the electric drive motor 1 is a motor shaft 17th arranged, which is coaxial with a transmission input shaft 18th of the transmission 3 runs and the drive torque of the electric drive motor 1 on the gearbox 3 transmits. Here is the transmission input shaft 18th in extension of the motor shaft 17th along a common central axis 37 arranged, with an end portion of the motor shaft 17th in an end section of the transmission input shaft designed as a hollow shaft 18th is recorded. The motor shaft 17th is by means of a roller bearing 6th rotatable in the connecting plate 4th stored. This is in a warehouse opening 12th in the connecting plate 4th a bearing element 15th recorded. On the case 2 of the electric drive motor 1 is a first flange 25th formed over which the housing 2 via fasteners 26th , in particular by means of screws or rivets, with a base support 5 the connecting plate 4th connected is.

The gear 3 includes a gear housing 14th and a transmission input shaft 18th . The transmission input shaft 18th is along a central axis 37 coaxial with the motor shaft 17th and arranged in extension of this. The transmission input shaft 18th has a toothed portion 30th on which a gear 29 with the transmission input shaft 18th is engaged. The transmission input shaft 18th is by means of a roller bearing 32 in a carrier element 31 , in particular in a planet carrier of a planetary gear, which in turn can be rotated in the gear housing by means of a further roller bearing 14th is stored. The carrier element 31 is by means of a roller bearing 24 rotatable in the bearing element 15th stored. The gearbox 14th has a second flange 27 on which one with the basic carrier 5 the connecting plate 4th via fasteners 28 , in particular via screws or rivets, is connected to one another.

The connecting plate 4th comprises a preferably metallic base support 5 on which a damping material 23 is attached. The connecting plate 4th has a first bearing opening in which a bearing element 15th inserted or pressed in. The motor shaft is in the bearing element 17th and that on the transmission input shaft 18th arranged carrier element 31 rotatably mounted. The combination of motor shaft 17th and transmission input shaft 18th is also called the first wave 21 designated. The connecting plate 4th also has a second bearing opening 13th on through which a second wave 22nd is led. It is at the second bearing opening 13th a mission 33 provided to the second shaft 22nd or one with the second wave 22nd to store connected component rotatably. The second wave 22nd has a first shaft segment 19th on which through the housing 2 of the electric drive motor 1 runs and a second shaft segment 20th , which through the gearbox 14th runs. One with the second wave 22nd The non-rotatably connected gear is by means of a roller bearing 34 rotatable on the insert 33 stored.

The connecting plate 5 also has a sensor 7th , in particular an acceleration sensor or a temperature sensor, which on the bearing element 15th is arranged and in particular vibrations on the bearing element 15th detected. The sensor 7th is via a conductive strand 10 , especially through a cable 9 or a guide element embedded in the damping material 8th , with a radial outside on the connecting plate 4th arranged transmission element 11 connected. The transmission element 11 processes the signals from the sensor 7th , provides a power supply for the sensor 7th and forwards the signals to a control unit (not shown). Due to the composite construction of the connecting plate 4th with a metallic base support 5 and a damping material 23 can be the weight for the connecting plate 4th be reduced. Alternatively, the transmission element 11 also a plug for making electrical contact with the connecting plate 5 be.

In 3 is an embodiment of the connecting plate 4th with a preferably metallic base support 5 and a damping material provided thereon 23 to recognize. Alternatively, the base support 5 can also be made from a fiber composite material, in particular from a plastic reinforced with carbon fibers. The basic carrier 5 includes the necessary storage and fastening points for fastening the connecting plate 1 even on a gearbox 14th and a housing 2 of the electric drive motor 1 . If the storage concerns moving and in particular rotating parts such as shafts, the physical connection in the connecting plate 4th Structure-borne sound waves initiated. This transmission or propagation of the structure-borne sound waves is caused by the damping material 23 attenuated, which in turn reduces the noise level of the transmission 3 is reduced overall. The damping material 23 can preferably be in the form of a molded plastic layer made of a highly damping polymer plastic, preferably made of a thermosetting plastic. The damping material 23 can in particular cohesively by molding on or additionally or alternatively also by a form fit with the base support 5 be connected.

The basic carrier 5 is preferably a metallic component, which can also be inexpensively formed in large numbers as a stamped and / or deep-drawn part. The metallic base carrier 5 has a greater modulus of elasticity than the damping material 23 and serves to take up the load. The connecting plate 4th has a first bearing opening 12th and another warehouse opening 13th for mounting axially parallel shafts 22nd , 23 on. At the first warehouse opening 12th is a sensor 7th arranged, which has a conductive strand 10 , especially over a cable 9 or an electrical conductor 8th with a transmission element 11 connected is. Therefore the fastening lugs, fastening openings and the bearing points 12th , 13th consciously on the basic carrier 5 arranged so that the reaction forces required for holding and mounting the components from the base support 2 be included. The damping material 23 can deliberately be arranged in such a way that it is not mechanically stressed and has a lower modulus of elasticity, which increases the damping of structure-borne sound vibrations. In 3 are the cable ducts in which the conductive strand 10 , especially the cable 9 , runs, shown visibly. These cable ducts are covered by a further plastic layer (not shown) after the conductive strand has been inserted 10 or the cable 9 closed by another layer of plastic. Alternatively or in addition, channels for conveying a liquid, in particular a hydraulic oil, can also be introduced into the connecting plate.

The connecting plate 4th includes one to the installation geometry in the transmission 3 adapted outer contour, so that it is, among other things, non-rotatably in the transmission 3 can support. The connecting plate further comprises 4th several mounting holes 4th for fastening the connecting plate 4th on the housings 2 , 14th of gearbox 3 and electric drive motor 1 or also for fastening further components arranged thereon, for example by means of screws passed through. The connecting plate further comprises 4th a first warehouse opening 12th for mounting a motor shaft 17th or a transmission input shaft 18th .

The connecting plate 4th is characterized by a composite construction, which is characterized by the base support 5 with the damping material provided on it 23 is formed. The damping material 23 can be on one side as well as on both sides of the base support 2 be provided. Furthermore, the damping material 23 be dimensioned in terms of extension, external geometry, arrangement and thickness in such a way that, as a result, sections of the base support that vibrate particularly strongly in a targeted manner 5 be dampened. The basic carrier 5 in designated areas e.g. B. to reduce weight also be filled with a thinner wall thickness, which then through the damping material 23 is specifically thickened or reinforced, so that the lower rigidity of the base support 5 can be at least partially compensated in the area of the thinner wall thickness. Furthermore, the base support 5 also specifically designed to create free spaces with a thinner wall thickness, so that the damping material 23 on the connecting plate 4th can be arranged without thereby reducing the maximum wall thickness of the connecting plate 4th is enlarged. 3 shows the end face of the connecting plate facing the transmission 4th .

Besides the advantage of the damping material 23 in the noise reduction can through the damping material 23 also the rigidity of the connecting plate 4th be optimized overall in terms of optimal force absorption and transmission.

In 4th is the connecting plate 4th in a view of the electric drive motor 1 facing end face shown. Here is the metallic base carrier 5 and the damping material 23 to recognize. Furthermore, the two bearing openings 12th , 13th as well as the transmission element 11 for the in 3 shown sensor 7th to see.

In 5 is a bearing element 15th for use in such a drive unit, in particular in such a connecting plate 4th shown. The bearing element 15th is preferably rotationally symmetrical to a central axis 37 executed. The bearing element 15th has a receiving area on its radially outer lateral surface 38 to accommodate the base support 5 on. The bearing element 15th also has a first bearing seat on its radially inner surface 35 for the rotatable mounting of one on the transmission input shaft 18th recorded and relative to the transmission input shaft 18th rotatable carrier element 31 on. Alternatively, the transmission input shaft can also be used 18th at the first bearing seat 35 be rotatably mounted. The outer ring of the rolling bearing becomes 24 in the warehouse 35 recorded. The bearing element 15th also has a second bearing seat 36 on which a roller bearing 6th for the rotatable mounting of the motor shaft 17th can be included. There is an outer ring for the rotatable mounting of the motor shaft 17th used rolling bearing 6th at the second bearing seat 36 on. The bearing element 15th can be designed in a composite construction, whereby the mechanically highly stressed parts of the bearing element 15th from a metallic Material are executed and lightly stressed areas are made of a polymer material. This can reduce the weight for the bearing element 15th to reduce.

List of reference symbols

1

Drive motor

2

casing

3

transmission

4th

Connecting plate

5

Basic carrier

6th

first camp

7th

sensor

8th

Guiding element

9

electric wire

10

conductive strand

11

Transmission element

12th

first warehouse opening

13th

second warehouse opening

14th

Gear housing

15th

Bearing element

16

Composite hub

17th

Motor shaft

18th

Transmission input shaft

19th

first shaft segment

20th

second shaft segment

21

drive shaft

22nd

second wave

23

Damping material

24

second camp

25th

first flange

26th

Fasteners

27

second flange

28

Fasteners

29

gear

30th

Gear section

31

Support element

32

warehouse

33

commitment

34

warehouse

35

first bearing seat

36

second bearing seat

37

Central axis

38

Receiving section

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102014118553 A1 [0004]
• EP 2659573 B1 [0005]

Claims (10)

Bearing element (15) for mounting a motor shaft (17) of an electric drive motor (1) and a rotating component (18, 31) of a gear (3) connected to the electric drive motor (1), characterized in that on a radially inner lateral surface of the bearing element (15), a first bearing seat (35) for mounting the rotating component (18, 31) of the transmission (3) and a second bearing seat (36) for the rotatable mounting of the motor shaft (17) are formed. Bearing element (15) after Claim 1 , characterized in that the bearing element (15) has a receiving section (38) on a radially outer lateral surface for receiving the bearing element (15) in a housing (2, 14) or a connecting plate (4). Bearing element (15) after Claim 2 , characterized in that the receiving section (38) is located in the axial direction between the first bearing seat (35) and the second bearing seat (36). Bearing element (15) according to one of the Claims 1 to 3 , characterized in that the bearing element (15) has a contact section on which a sensor (7) for monitoring the bearing element (15) can be received. Bearing element (15) after Claim 4 , characterized in that the contact section is formed on an outer jacket surface of the bearing element (15). Bearing element (15) according to one of the Claims 1 to 5 , characterized in that the bearing element (15) is designed as a composite hub (16). Bearing element (15) after Claim 6 , characterized in that the composite hub (16) has a metallic base body and an area formed on the metallic base body made of a polymer material. Bearing element (15) according to one of the Claims 1 to 7th , characterized in that a receiving section (38) for receiving a base support (5) of a connecting plate (4) is formed on the position element (15). Connecting plate (4) for connecting an electric drive motor (1) to a gear (3), the connecting plate (4) having at least one bearing opening (12, 13) for the passage of a shaft (17, 18, 21, 22), the Connecting plate (4) has a base support (5) and a damping material (23) connected to the base support (5), with a bearing element (15) according to one of the at least one bearing opening (12, 13) of the base support (5) Claims 1 to 8th is recorded. Drive unit with an electric drive motor (1) and a gear (3), the electric drive motor (1) and the gear (3) via a bearing element (15) according to one of the Claims 1 to 8th are connected.

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