DE102017211809A1 - Drive unit for a motor vehicle with an electric machine and a clutch - Google Patents

Abstract

A drive unit (10) for a motor vehicle is described, comprising an electric machine (12) and a switchable clutch (20) for producing a rotational drive connection of the rotor (18) with a drive element (26). The clutch (20) has a disengaging member (46) which is axially displaceable by means of an actuating device (24). The actuating device (24) comprises an electric actuator motor (54) with an actuator shaft (56) and a releasing arrangement (50) operatively connected therewith, which converts a rotational movement into a translatory movement acting on the disengagement member (46) of the coupling (20) and to a rotatable and axially to the release member (46) fixed input member (50a) and an axially displaceable to this output member (50b) which is in operative connection with the release member (50). Between the actuator shaft (56) and the disengagement assembly (50) an angle gear is arranged, which is designed as a high-ratio crown gear (58) arranged on the actuator shaft (56) drive pinion (60) and with a driven gear (64), which is in operative connection with or forms the input element (50a) of the disengagement arrangement (50).

Description

The invention relates to a drive unit for a motor vehicle according to the preamble of the independent claim.

In a hybrid vehicle, in particular in a full hybrid, a disconnect clutch is provided between the internal combustion engine and the electric machine, whereby the internal combustion engine can be decoupled and the vehicle can be driven solely by the electric machine.

The DE 10 2012 216 601 A1 discloses against this background, a generic drive unit in which a disengagement assembly is provided with a ball ramp drive for actuating the disconnect clutch, which can be acted upon by two gear stages, in particular designed as a worm gear angular gear and a spur gear by an actuator motor with a disengaging.

There is a need in such a compact drive unit to perform this, in particular with regard to the actuating device of the clutch, even more space-saving.

The object is achieved by a drive unit having the features of the independent patent claim.

The invention provides, in a drive unit of the type mentioned, the angular gear of the actuator as a high translational crown gear with a arranged on the actuator shaft or drive pinion and run with a driven gear which is in operative connection with the input element of the disengagement assembly or this forms.

In the drive unit can thus in the prior art according to the DE 10 2012 216 601 A1 In addition to the angular gear existing spur gear omitted, since a required speed reduction can be generated solely by the crown gear. Advantageously, the angular gear can have a ratio i of 15-20, in particular of i greater than or equal to 20. Thus, the angle gear is a high-ratio angle gearbox with high efficiency.

In the dependent claims advantageous refinements and developments of the invention are given.

A particularly easy to produce crown gear can be represented by the output gear or crown gear of the crown gear is performed without effort due to the free formability as a plastic injection molded part. The production of the ring gear as an injection molded part avoids the high production cost that occurs in a chip-forming production, which results from bumping with a bidentate cutting wheel.

The high efficiency of the crown gear is achieved because there is almost no axial sliding during a rotational movement of the gears.

Preferably, the drive pinion can be designed with a number of teeth from 1 to 5, in particular with a number of teeth between 2 and 5. An adaptation of the translation of the Kronengetriebes in various applications can be done using a given drive pinion by only the teeth, in particular the number of teeth of the output gear or ring gear is modified.

According to a further development, it can be provided that the angle between the actuator axis, that is to say the axes of the drive pinion and the axis of the output gear, that is to say the disengagement axis, is selected in the range from 80 ° to 100 °. For example, an otherwise required undercut can be avoided in an advantageous manner by a slight inclination of the actuator shaft. As a result, the production of the proposed crown gear is further simplified.

Furthermore, it is conceivable that in the crown gear arrangement a possible axial offset is provided in order to change the tooth geometry of the ring gear.

Advantageously, the teeth of the output gear can be designed arcuate in a plan view of the crown or crown wheel. There is thus a curved toothing. The shape of the teeth of the output gear results as a conjugate profile to the drive pinion. In particular, the teeth can have a different angle than 90 ° relative to the outer edge or outer edge of the driven wheel. This means that the teeth on the output gear are not aligned radially and thus are not perpendicular to the edge of the output gear.

Advantageously, the teeth of the output gear can be arranged on a circular ring segment, whereby they occupy only a partial surface of the driven wheel. Preferably, the circular ring segment is located on the outer edge of the driven wheel. The driven wheel itself does not necessarily have to be present as a complete circular disk, but can be formed by a circular segment.

Preferably, the teeth of the output gear may have a length between 10 mm and 30 mm. This length is sufficient to transmit the required torque when interacting with the drive pinion.

Advantageously, the drive pinion may have a helical toothing, which is formed directly on the actuator shaft or on a pinion arranged there. In principle, the pinion can also have a straight toothing, which can be represented by means of a gear at the end of the actuator shaft.

In this case, the helix angle of the helical gearing may advantageously be greater than 25 °. This gives a strong helical toothing, resulting in an advantageous profile of the teeth of the driven wheel. In particular, it is then also possible to use the same drive pinion in a crown gear teeth and a spur gear, which can keep the kept up spare parts and production machines low, resulting in lower costs.

Preferably, the length of the drive pinion can be greater than or equal to a pitch of the toothing of the drive pinion. The pitch height is the axial distance of two points located at the same circumferential position, between which a helical toothing once revolves. Furthermore, the length of the drive pinion can be less than three pitch heights. The helical gear rotates the drive pinion so one to three times.

Advantageously, the drive pinion can be formed as a helical involute spur gear. In other words, the pinion is designed as a cylindrical wheel with an involute profile.

The axis of the actuator and the axis of the driven wheel, which in this case forms the Ausrückachse, can intersect without cutting, i. the axes can be arranged skewed to each other. Alternatively, the axes can also intersect. The described toothing of both the drive pinion and the driven wheel makes it possible for the drive pinion to be displaced freely in both directions with respect to the position of the longitudinal axis of the drive pinion, that is to say the position of the actuator shaft. Furthermore, the drive pinion can in turn be displaced parallel to a radius line of the output gear relative to the position of its longitudinal axis within the plane spanned by the driven wheel and engage the toothing formed there. This results in a free positioning of the actuator motor.

Overall, the proposed highly translating crown gear allows a variety of customization options, especially in the positioning of the actuator motor, a freer adaptation of the actuator to existing space.

According to one embodiment of the invention, it is advantageous to carry out the disengagement arrangement as a ball ramp drive. In this case, the input element and the output element are preferably designed with corresponding ball ramps or tracks and between these running balls and arranged axially relative to one another. Particularly preferably, the ball tracks or ramps are arranged frontally on the input and output element, resulting in a space-saving and only small radial expansion of the disengagement order result.

A particularly space-saving design of the drive unit can be achieved by the actuator shaft as already explained above, within a certain angular range transverse to the axis of rotation A the drive unit, which can coincide with the Ausrückachse, is directed and axially adjacent to the stator and by the actuator motor is disposed radially outside of the electric machine serving as a drive unit. In this case, the actuator motor and the drive unit space-saving overlap each other axially. The actuator motor can preferably be fixed to a housing surrounding the drive unit, where it is particularly easy to access for maintenance or replacement.

The actuating device can be fixed at least indirectly on the stator of the electric machine, in particular with the actuator shaft, optionally with the reduction gear and with the disengagement arrangement, and be supported against an acting clutch actuation force. For this purpose, preferably a stator or a fixedly connected to the stator further element, such as a connected to the stator housing or the like is suitable.

The proposed drive unit can be prefabricated as an independent module and inserted as a whole unit in a drive train of a hybrid vehicle.

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

• 1 eine Axialschnittdarstellung einer Antriebseinheit mit einer elektrischen Maschine und einer Lamellenkupplung mit einer Betätigungseinrichtung;
• 2 eine Draufsicht auf ein Kronenradgetriebe der Betätigungseinrichtung von 1;
• 3 eine Axialschnittdarstellung einer gegenüber 1 abgewandelten Antriebseinheit mit einer elektrischen Maschine und einer Reibungskupplung mit einer Betätigungseinrichtung.

Show it:

• 1 an axial sectional view of a drive unit with an electric machine and a multi-plate clutch with an actuator;
• 2 a plan view of a crown gear of the actuator of 1 ;
• 3 an axial sectional view of one opposite 1 modified drive unit with an electric machine and a friction clutch with an actuator.

The drive unit shown in the figures 10 for a hybrid vehicle includes one as an electric machine 12 trained drive unit 14 with a stator 16 and with a coaxial to this about a rotation axis A rotatably mounted rotor 18 , The stator 16 is within a substantially cylindrical stator carrier 16a taken, which at the same time a housing 10c the drive unit 10 formed. The electric machine 12 In the present case, it is embodied as an internal rotor machine and, depending on the prevailing space conditions, can in principle also be designed as an external rotor machine.

The drive unit 10 further includes a here in unit with the electric machine 12 trained switchable coupling 20 , what a 1 as a dry-running or wet-running multi-disc clutch 22 is executed and which by means of an actuating device 24 is operable. The coupling 20 serves to produce a rotary driving connection of the rotor 18 with a further drive element of the drive unit 10 , here in particular an intermediate shaft 26 which is an input element 10a the drive unit 10 forms and which by means of a toothing 26a via a torsion damper 28 with the crankshaft 30 a combustion engine not shown here can be brought into rotary driving connection or is brought. The intermediate shaft 26 is by means of a warehouse 32 rotatably on a first partition wall 33 set, which differs from the housing 10c proceeding radially inward extends and the bearing 32 receives.

The rotor 18 is from an axially extending portion 34a a rotor carrier 34 will be carried. At this closes a radially extending section 34b on, with a shaft section 34c is connected or trains this. The shaft section 34c acts as an initial element 10b the drive unit 10 , Like in the 1 recognizable, is the shaft section 34c by means of a warehouse 36 on a second partition 38 set, which is also from the housing 10c extending radially inwards. The electric machine 12 , the coupling 20 and at least part of the actuator 24 be in one of the partitions 33 . 38 spanned recording room 40 added.

To form the multi-plate clutch 22 are at an axial section 26b the intermediate shaft 26 non-rotatable, but axially displaceable inner disks 22a added. These inner slats 22a can by the action of the actuator 24 each with axially adjacent, at the axial portion 34a of the rotor carrier 34 non-rotatable, but also axially displaceable guided outer plates 22b be brought into frictional engagement. The multi-plate clutch 22 is thus within one of the rotor 18 trained annulus 42 added. The coupling 20 . 22 is in the present case of the normally-closed type executed, which from the inner and outer plates 22a b formed lamellar package by the effect of a diaphragm spring 44 trained force accumulator is compressed and where the diaphragm spring 44 on the rotor support section 34a axially supported.

The release mechanism 46 the clutch 20 includes an array of multiple plungers 46a , which the rotor carrier section 34b axially reach through and the one end plate against the action of the diaphragm spring 44 shift, which relieves the disk pack and the clutch 20 can be opened. The introduction of an actuating force on the plunger 46a done with a transfer plate 46b , Which via a serving for rotational decoupling release bearing 48 with a disengagement arrangement 50 are connected. The disengagement arrangement 50 comprises a rotatable and axial, in particular to the release member 46 fixed input element 50a and an output member axially displaceable therefrom 50b which is on the pestles 46a acts. In the present case is the disengagement arrangement 50 as a ball ramp 51 formed between the input element 50a and the output element 50b guided in axial ramps balls balls 50c to run.

The disengagement arrangement 50 is at a reception area 38a the partition 38 , especially within sections 38b - d established. The connection of the axially displaceable output element 50b to a non-rotatable bearing ring in the receiving space 40 located release bearing 48 done by a further arrangement of plungers 52 , which for this purpose the section 38c axially reach through.

The actuating device 24 is in the embodiment at least partially axially within the electric machine 12 added.

The recording room 40 can be designed as a wet room and in the area of partitions 33 . 38 opposite adjacent drying rooms be sealed. For this purpose, in particular also on the actuating device 24 in the area of the ram 52 and / or the elements of the disengagement assembly 50 appropriate sealing means are provided, so that the actuating device 24 partly arranged in the drying room and partly in the wet room.

The actuating device 24 further comprises an electric actuator motor 54 with an in the illustrated plane transverse, preferably at an angle of 80 ° -100 ° to the axis of rotation A the electric machine 12 aligned and rotatable about an axis actuator shaft 56 , which with the input element 50a the disengagement arrangement 50 is in operative connection and which is adapted to a rotational movement of the actuator shaft 56 in one on the disengagement organ 46 the clutch 20 to translate translational movement.

To generate a speed reduction or a torque ratio is between the actuator shaft 56 and the disengagement assembly 50 a bevel gear in the design of a high translating crown gear 58 intended. The crown gearbox 58 includes one on the actuator shaft 56 trained or arranged there drive pinion 60 and one as a ring gear 62 executed output gear 64 which is connected to the input element 50a the disengagement arrangement 50 rotatably connected. The ring gear 62 can also be the input element at the same time 50a the disengagement arrangement 50 form and have, for example, ball tracks of a ball ramp drive. The drive pinion 60 and the output gear 64 are designed such that a resulting translation i of the crown gear 58 greater or equal 20 is provided. The driven wheel 64 is doing as a plastic injection molded part of a high-strength and at the same time low-wear plastic, for example, a thermoplastic with the name PA 6 . PA 66 or PA 6G produced. Likewise, the drive pinion 60 be designed as a plastic injection molded part of the aforementioned thermoplastics or another material.

The crown gearbox 58 and the disengagement assembly 50 are spatially adjacent, in particular immediately adjacent to the intermediate wall 38 but outside the recording room 40 arranged.

Out 1 it can be seen that the axis of rotation C the actuator shaft 56 or the actuator motor 54 and the axis of the driven wheel 64 or the release axis B are arranged at a right angle, ie at an angle of 90 ° to each other. This illustration is merely exemplary, since, as already mentioned, the angle or the inclination between these axes B . C depending on the application can also be easily modified.

2 shows the crown gear 58 isolated and schematized in plan view, wherein the representation of the drive pinion 60 a gearing 61 directly on the actuator shaft 56 is executed. You can tell that the teeth 64a the driven wheel 64 arcuate designed. For clarity, the tooth heads are shown only as arcuate lines. The teeth 64a the driven wheel 64 occupy an annular circle segment 66 which is in 2 covers an angular range of less than 180 °, so slightly less than a semicircle. The circle segment 66 can also cover smaller or larger angle ranges. The teeth 64a the driven wheel 64 have a length between 10 mm and 30 mm. Accordingly, the drive pinion 60 a length greater than a pitch of the toothing 61 of the drive pinion 60 exhibit.

Out 2 is also apparent that the drive pinion 60 is designed as a helical elvolventisches spur gear. The drive pinion 60 has two teeth 61a . b and a helix angle of about 33 degrees. Thus there are always two or three teeth 64a the driven wheel 64 with the helical toothing of the drive pinion 60 engaged.

With a view to 1 is the actuator motor 54 radially outside the electric machine 12 arranged. The actuator shaft 56 extends axially adjacent to the stator 16 and transverse to the axis of rotation A the drive unit 10 or the electric machine 12 , which in this case with a release axis B the disengagement arrangement 50 coincides.

The illustrated housing 10c may be, for example, a transmission housing or a separate intermediate housing of the vehicle drive train. The actuator motor 54 can be on the outside of the case 10c be determined.

The further, with 3 illustrated embodiment is based fundamentally on that of 1 and 2 so that in the following description, essentially only existing differences will be discussed.

In the embodiment of 3 is the clutch 20 as a dry friction clutch 23 educated. The rotor carrier 34 in turn forms with a radially inner axial extension 34c the output element 10b the drive unit 10 , Radial inside of the rotor 18 formed annulus 42 is an axially displaceable pressure plate 23a arranged, which is a friction or clutch disc 23b act on a closing force and frictionally engaged to the Rotroträgerabschnitt 34b can set. The section 34b thus forms an abutment or a Gegenreibplatte the clutch 23 out. The friction disc 23b is with the intermediate shaft 26 connected, which in turn the input element 10a the drive unit 10 forms. With the clutch closed 20 can with the interposition of the torsion damper 28 a rotary driving connection to one with the intermediate shaft 26 connectable output or crankshaft 30 an internal combustion engine are formed.

For transmitting an actuating force to the pressure plate 23a serves as a lever element, in particular as a diaphragm spring 47 trained release member 46 , The diaphragm spring 47 is to a radial extension 34d of the rotor carrier 34 pivoted and lies with a radially outer ring portion 47a on the pressure plate 23a and with radially inwardly extending spring tongues 47b on the rotatable bearing ring of the release bearing 48 at.

The extension 34d thus provides a further support region of the rotor 18 which has an associated section 34e and by means of a warehouse 37 at a radially inner cylindrical portion 33a the partition 33 is stored.

The actuator shaft 56 , the crown gear 58 and the disengagement assembly 50 are in this example axially adjacent to the intermediate wall 33 but within the recording room 40 arranged. The crown or crown wheel 62 of the crown gear 58 attacks as before 1 explained to the input element 50a the disengagement arrangement 50 on or is formed directly as this. The starting element 50b and the release bearing 48 are positioned directly adjacent to each other axially, that is without the interposition of distance-bridging power transmission elements.

However, the provision of an angle gear in the form of a crown gear is by no means mandatory in the above-described drive unit, but merely represents an advantageous variant. In principle, provided between the actuator motor and the input element of the disengagement arrangement gearbox in any other way with respect to previous description.

LIST OF REFERENCE NUMBERS

10

drive unit

10a

casing

10c

casing

12

electric machine

14

power unit

16

stator

16a

stator

18

rotor

20

clutch

22

multi-plate clutch

22a

inner plate

22b

outer plate

23

friction clutch

23a

pressure plate

23b

clutch disc

24

actuator

26

intermediate shaft

26a

gearing

26b

axial section

28

Dampers

30

spherical wave

32

camp

33

partition

33a

cylindrical section

34

rotorarm

34a-e

Rotor support section

36

camp

38

partition

38a

reception area

40

accommodation space

42

annulus

44

diaphragm spring

46

Ausrückorgan

46a

tappet

46b

transfer plate

47

diaphragm spring

47a

ring section

47b

spring tongue

48

release bearing

50

release assembly

50a

input element

50b

output element

50c

Bullet

51

Ball ramp drive

54

Actuator motor

56

Actuator shaft

58

crown-gear

60

pinion

61

gearing

62

crown

64

output gear

64a

tooth

66

circular segment

A

Rotary axis of the drive unit

B

Ausrückachse

C

Servo axis

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102012216601 A1 [0003, 0007]

Claims (12)

Drive unit (10) for a motor vehicle comprising - a drive unit (14) designed as an electric machine (12) with a stator (16) and with a rotor (18) rotatably mounted about a rotation axis A coaxial therewith, - a switchable coupling (20) for producing a rotary driving connection of the rotor (18) with a drive element (26) of the drive unit (10), wherein - the coupling (20) has a disengaging member (46) which is axially displaceable by means of an actuating device (24), wherein - the actuating device (24) comprises - an electric actuator motor (54) having an actuator shaft (56) and - a release assembly (50) operatively connected to the actuator shaft (56) which rotates the actuator shaft (56) into a release member (46). the translation (50) acting translational movement and wherein - the disengagement assembly (50) has a rotatable and axially to the release member (46) fixed input element ( 50a) and an axially displaceable output element (50b), which is in operative connection with the disengagement member (50), wherein - between the actuator shaft (56) and the disengagement assembly (50) an angular gear is arranged, characterized in that the angular gear is designed as a high translational crown gear (58) with a drive pinion (60) arranged or formed on the actuator shaft (56) and with a driven gear (64) operatively connected to or forming the input member (50a) of the disengagement assembly (50) , Drive unit to Claim 1 , characterized in that the output gear (64) is designed as a plastic injection molded part. Drive unit to Claim 1 or 2 , characterized in that the drive pinion (60) has a number of teeth of 1 to 5, in particular a number of teeth between 2 and 5, having. Drive unit according to one of the preceding claims, characterized in that an angle between the axes of the drive pinion (60) and output gear (64) is selected in the range of 80 ° to 100 °. Drive unit according to one of the preceding claims, characterized in that the teeth of the output gear (64) are designed arcuate. Drive unit according to one of the preceding claims, characterized in that the teeth of the output gear (64) on a circular ring segment (66) are arranged. Drive unit according to one of the preceding claims, characterized in that the teeth (64a) of the output gear (64) have a length between 10 mm and 30 mm. Drive unit according to one of the preceding claims, characterized in that the drive pinion (60) has a helical toothing. Drive unit to Claim 8 , characterized in that a helix angle of the helical gearing is greater than 25 °. Drive unit according to one of the preceding claims, characterized in that the length of the drive pinion (60) is greater than or equal to a pitch height of the toothing of the drive pinion (60). Drive unit according to one of the preceding claims, characterized in that the drive pinion (60) is designed as a helical involute spur gear. Drive unit according to one of the preceding claims, characterized in that the disengagement arrangement (50) is designed as a ball ramp drive (51).

Images