DE102011104242A1 - Crankshaft pulley - Google Patents

Abstract

The invention relates to a crankshaft pulley for transmitting torque between a crankshaft and a belt drive, with at least one freewheel and a gear. The invention is characterized in that the transmission in the crankshaft pulley is combined with a braking device outside of the crankshaft pulley.

Description

The invention relates to a crankshaft pulley for transmitting a torque between a crankshaft and a belt drive, with at least one freewheel and a transmission.

From the German patent application DE 10 2007 021 233 A1 a powertrain for a motor vehicle with a power transmission unit is known, which has two acting in opposite directions freewheels and a planetary gear.

The object of the invention is to further optimize a crankshaft pulley according to the preamble of claim 1, in particular with regard to different operating functions and / or the required installation space.

The object is achieved in a crankshaft pulley for transmitting a torque between a crankshaft and a belt drive, with at least one freewheel and a transmission, characterized in that the transmission is combined in the crankshaft pulley with a braking device outside the crankshaft pulley. By the braking device different modes, for example, a starter generator and / or a stationary air conditioning can be realized in a simple manner. In addition, the braking device allows a demand-dependent activation and / or deactivation of the transmission in certain operating conditions, such as the stationary air conditioning. According to an essential aspect of the invention, the freewheel and the transmission are arranged in the interior of the crankshaft pulley. An absorber mass is preferably also arranged in the interior of the crankshaft pulley. In contrast, the braking device is arranged outside the crankshaft pulley, in particular radially outside a belt track of the crankshaft pulley. According to a further aspect of the invention, the braking device is arranged in the axial direction overlapping the crankshaft pulley. In this case, the braking device is preferably arranged in the vicinity of the crankshaft pulley. As a result, all the functions mentioned can be realized in a space-independent manner. The freewheel can be bridged for a pulse start by means of the braking device, so that the starter generator can drive the crankshaft via the transmission.

A preferred embodiment of the crankshaft pulley is characterized in that the braking device is designed as a frictional or positive electric brake. The braking device preferably comprises a coil carrier with a coil which generates a magnetic field when it is energized. As a result of the magnetic field, an armature of the braking device can be attracted as needed to close the braking device. According to an essential aspect of the invention, the transmission is activated or deactivated as required by closing the brake device.

A further preferred embodiment of the crankshaft pulley is characterized in that the braking device comprises a movable anchor body and a stationary coil carrier, which represent friction partners or form-fitting partners of the braking device. The bobbin serves to receive the coil of the braking device. Fixed means that the bobbin is fixed relative to the crankshaft pulley. For this purpose, the bobbin is attached to a support structure, for example to a crankcase, outside the crankshaft pulley. The fixed coil support provides the advantage that no rotary feedthrough is required for the voltage supply of the coil.

A further preferred embodiment of the crankshaft pulley is characterized in that the anchor body and / or the coil carrier of the brake device are arranged radially outside a belt track of the crankshaft pulley / is. The anchor body and the coil carrier are preferably arranged radially outside and in the axial direction overlapping the crankshaft pulley, in particular the belt track of the crankshaft pulley. According to a further aspect of the invention, no additional axial space is claimed by the braking device.

A further preferred embodiment of the crankshaft pulley is characterized in that the transmission is designed as a planetary gear with a ring gear which is rotatably connected to the anchor body of the braking device. The ring gear is disposed in the crankshaft pulley, that is radially within the belt track. The anchor body, however, is located outside the belt track. The anchor body is connected, for example by a connecting element, for example a sheet metal part, with the ring gear. The anchor body can also be made in one piece with the ring gear.

A further preferred embodiment of the crankshaft pulley is characterized in that the armature body is spaced in the axial direction of the bobbin in the de-energized state of a coil of the braking device. The anchor body is in the de-energized state of the coil, for example, by the biasing force of a spring device, spaced from the bobbin that no frictional engagement between the Anchor body and the bobbin occurs. The braking device is normally preferably open. For a combustion start, that is to start an internal combustion engine with the aid of a starter generator, the planetary gear is activated by means of the braking device.

Another preferred embodiment of the crankshaft pulley is characterized in that the anchor body is braked with the ring gear in the energized state of the coil so that one or the belt track of the crankshaft pulley is coupled via the transmission with the crankshaft. About the activated by means of the braking device planetary gear can be provided in a simple manner required for starting the engine torque.

Another preferred embodiment of the crankshaft pulley is characterized in that the crankshaft pulley comprises a pulley freewheel having an inner ring which is rotatably connected together with a planetary carrier of the planetary gear with the crankshaft, and having an outer ring which is rotatably connected to the belt track of the crankshaft pulley. The pulley freewheel effective between the crankshaft and the belt track, for example, serves to dampen torque surges in the generator operation of the crankshaft pulley.

Another preferred embodiment of the crankshaft pulley is characterized in that the outer ring of the pulley freewheel is combined with a sun gear of the planetary gear. Combined means that the outer ring of the pulley freewheel can be integrally connected to the sun gear of the planetary gear. But the outer ring can also be firmly bonded to the sun gear and with the help of fasteners.

As an alternative to the two preceding embodiments, the rotationally fixed connections of the freewheel can also be reversed.

A further preferred embodiment of the crankshaft pulley is characterized in that the coil carrier of the braking device has two recesses for performing at least a portion of a belt of the belt drive. The size of the recesses depends on the size and arrangement of the bobbin outside the crankshaft pulley. The size and shape of the recesses also depends on the belt itself and the arrangement of the belt in the belt drive. The size and shape of the recesses are preferably selected so that the function of the belt is not affected during operation of the belt drive. The recesses may be designed as unilaterally open slots, in which engages at least a portion of the belt.

The invention further relates to a drive train of a motor vehicle, as described, for example, in German Offenlegungsschrift DE 10 2007 021 233 A1 is disclosed. The power transmission unit described therein is replaced by the crankshaft pulley according to the invention.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, various embodiments are described in detail. Show it:

1 a highly simplified representation of a drive train of a motor vehicle with a crankshaft pulley according to the invention;

2 a section from 1 overlooking a hinted belt and

3 a detailed view of the crankshaft pulley from the 1 and 2 in longitudinal section.

In the 1 to 3 is a crankshaft pulley 1 shown in different illustrations. The crankshaft pulley 1 includes a pulley track 2 , which is also referred to as pulley or belt track for short, and serves, for example, to couple a belt of a belt drive with a belt starter generator and / or at least one auxiliary unit, such as an air conditioning compressor.

The crankshaft pulley 1 is in the drive train of a motor vehicle, as for example in the German patent application DE 10 2007 021 233 A1 is disclosed on a crankshaft 4 attached, which is about a rotation axis 5 is rotatable. The motor vehicle is, for example, a hybrid vehicle with an internal combustion engine and an electric machine, which is embodied in particular as a generator. For example, the hybrid vehicle may be driven by the internal combustion engine alone or by the electric machine alone.

Into the crankshaft pulley 1 is a pulley freewheel 6 integrated. The pulley freewheel 6 is between the belt track 2 and the crankshaft 4 effective. The pulley freewheel 6 Serves to dampen torque surges during generator operation of the crankshaft pulley.

Into the crankshaft pulley 1 is furthermore a Tilgermassenträger 7 integrated. The Tilgermassenträger 7 is fixed to the crankshaft 4 connected. With the interposition of a rubber track 8th is radially outward on the Tilgermassenträger 7 a damper mass 9 appropriate. The absorber mass 9 FIG. 12 illustrates a crankshaft reducer that serves to eliminate unwanted torque oscillations, torque nonuniformities and / or torque shocks for protecting the crankshaft during operation of the internal combustion engine.

Into the crankshaft pulley 1 is also a transmission 10 integrated, which is preferably designed as a planetary gear. The planetary gear 10 includes one on a crankcase 25 Lockable ring gear 11 , With the ring gear 11 comb planet gears 12 attached to a planet carrier 13 are rotatably mounted. The planet wheels 12 Comb further with a sun gear 14 that together with the ring gear 11 , the planet wheels 12 and the planet carrier 13 into the crankshaft pulley 1 is integrated.

The in the 1 and 2 illustrated crankshaft pulley 1 includes a braking device 20 , which is designed as an electric brake, in particular as a frictional magnetic brake. The braking device 20 includes a fixed bobbin 22 that a coil 23 carries and over a connecting element 24 on a crankcase 25 is mounted in the drive train of the motor vehicle. The stationary coil carrier 22 represents a first friction partner of the braking device 20 dar. An anchor body 28 represents a second friction partner of the braking device 20 dar. The anchor body 28 is in the axial direction relative to the bobbin 22 movable.

When the anchor body 28 in the axial direction of the fixed bobbin 22 is spaced, then the anchor body 28 relative to the bobbin 22 rotate. If the coil 23 is energized, an electromagnetic field is generated, the anchor body 28 so attracts that the anchor body 28 frictionally engaged with the fixed bobbin 22 is connected. Then the braking device 20 closed and the anchor body 28 stand still. In the closed state of the braking device 20 is the anchor body 28 frictionally engaged with the bobbin 22 and over the connecting element 24 firmly with the crankcase 25 connected. In this way, the ring gear 11 be set or released.

If the internal combustion engine, which is also referred to as an internal combustion engine, in a so-called start / stop operation or in a purely electric driving of the hybrid vehicle, stands still, that is, does not output torque, then with the brake device open 20 be operated by the starter generator via the belt drive a connected air conditioning compressor for stationary air conditioning. When the braking device 20 closed, then the starter generator, the crankshaft 4 over the belt drive and the planetary gear 10 in rotation, whereby the internal combustion engine is started. Through the planetary gear 10 The torque provided by the starter generator via the belt drive is increased, thereby enabling a cold start of the brake engine.

After a starting process of the internal combustion engine, the braking device 20 opened again. When the brake device is open 20 can the starter generator via the pulley freewheel 6 from the crankshaft 4 are driven. This operation is also referred to as regenerative operation. At the same time, crankshaft vibrations are caused by the pulley freewheel 6 steamed.

At the in 3 illustrated embodiment can be seen that the pulley freewheel 6 an inner ring 41 and an outer ring 42 includes. The inner ring 41 of the pulley freewheel 6 is with the help of a mounting screw 44 at the (in 2 not shown) attached crankshaft. The outer ring 42 is by a rolling bearing designed as a ball bearing 45 on a screw head of the mounting screw 44 rotatably mounted. In addition, the outer ring 42 with the help of a rolling bearing designed as a roller bearing 46 on the inner ring 41 of the pulley freewheel 6 rotatably mounted.

The Tilgermassenträger 7 is on the inner ring 41 of the pulley freewheel 6 attached. This is the absorber mass carrier 7 firmly connected to the crankshaft. The planet carrier 13 is via an axial connecting portion 48 and a radial flange 49 also on the inner ring 41 of the pulley freewheel 6 attached. This is the planet carrier 13 also firmly connected to the crankshaft.

The outer ring 42 of the pulley freewheel 6 is via a connecting flange 60 firmly with the belt trace 2 connected. The belt trace 2 is integral with the connecting flange 60 connected. In addition, on the outer ring 42 the sun wheel 14 of the planetary gear 10 appropriate. The ring gear 11 of the planetary gear 10 is radially inward on the connecting element 29 of the anchor body 28 the braking device 20 appropriate.

According to another aspect of the invention is parallel to the rolling bearings 45 . 46 arranged pulley freewheel 6 not centrifugal lifted executed. The inner ring 41 of the pulley freewheel 6 is with the planet carrier 13 of the planetary gear 10 connected. The on the planet carrier 13 stored planet gears 12 comb with the ring gear 11 that has a connector 29 with the armature disk designed as an anchor body 28 connected is. The anchor body 28 is together with the coil carrier 22 radially outside the belt track 2 the crankshaft pulley 1 arranged. According to a further aspect of the invention, the bobbin is 22 how to get in 1 looks on a the crankcase 25 opposite side of the anchor body 28 arranged. A belt 30 the belt drive extends partially through the bobbin 22 ,

In 2 you can see that the indicated by dashed lines belt 30 through two recesses 31 . 32 passed through in the coil carrier 22 are provided. The two recesses 31 . 32 are designed as unilaterally open slots whose arrangement and size to the size and the arrangement of the belt 30 are adjusted. It has the belt 30 in the recesses 31 . 32 of the bobbin 22 sufficient clearance, so that the function of the belt 30 during operation of the belt drive is not affected.

The braking device 20 is in operation in the 1 to 3 shown crankshaft pulley 1 is operated only for a short period of time at a combustion start, that is, when the internal combustion engine, which is also referred to as an internal combustion engine, is started by the starter generator. Therefore, the coil carrier can 22 , which is also referred to as a bobbin, in relation to the anchor body 28 , which is also referred to as a yoke, small dimensions. The coil carrier 22 protrudes radially outside the belt track 2 in the axial direction so in the area of the belt track 2 that is the coil carrier 22 and the belt track 2 partially overlap in the axial direction. The overlap in the axial direction is through the recesses 31 . 32 allows. This provides the advantage that a particularly compact design, especially in the axial direction, the crankshaft pulley 1 is possible.

To start the internal combustion engine is the normally open braking device 20 energized and thereby closed. This will turn on the starter generator and the belt 30 on the belt track 2 applied torque on the sun gear 14 of the planetary gear 10 transfer. Because the ring gear 11 through the closed brake device 20 is braked, an increased torque on the planet carrier 13 that generates the crankshaft 4 of the internal combustion engine set to start for rotation. The pulley freewheel 6 is in this operating condition, which also referred to as starter generator mode, overtaken in the freewheeling direction.

After starting the internal combustion engine is the energization of the braking device 20 off. By appropriate springing the braking device 20 open, so no more torque on the braking device 20 can be transferred. Then that's from the crankshaft 4 provided torque on the closing in this torque direction pulley freewheel 6 with positive torque surges to drive the belt drive on the belt track 2 transfer. In this operating state, the generator can be driven by the internal combustion engine and an electrical energy storage can be charged.

With negative torque surges, the belt drive can due to its inertia, the crankshaft 4 through the pulley freewheel 6 Overhaul, eliminating the function of the pulley cushioning and belt life 30 and the aggregates connected to it is ensured. The planetary gear 10 is due to the opened brake device 20 on the ring gear 11 decoupled, so no torque transfer to the planet carrier 13 takes place. During the overtaking phases of the pulley freewheel 6 can only the ring gear 11 rotate freely.

To a rattling of the gears of the planetary gear 10 To prevent the planetary gears 12 be sprung in the axial direction via friction plates. The planetary gear 10 But it can also be performed in other ways rattle and / or play.

With the combustion engine stopped and the braking device not energized 20 can the belt trace 2 rotate freely in one direction, as the pulley freewheel 6 can overtake. This allows the starter generator with stationary crankshaft 4 drive an air conditioning compressor connected to the belt drive in order to display the auxiliary air conditioning function. In this operating state, the ring gear can 11 of the planetary gear 10 in an opposite direction of rotation to the belt track 2 twist.

If the engine is to be started during the stationary air conditioning, which is also referred to as pulse start, then the frictional braking device 20 with rotating belt track 2 energized and closed. As a result, the internal combustion engine can be started. Braking the belt trace 2 for closing the brake device 20 not necessary. As a result, an operating state designated as a change of mind can also be represented. A change of mind operating state is a stopping and restarting of the internal combustion engine referred to before the crankshaft 4 has come to a standstill.

LIST OF REFERENCE NUMBERS

1

Crankshaft pulley

2

belt track

4

crankshaft

5

axis of rotation

6

Pulley one-way

7

Tilgermassenträger

8th

rubber track

9

absorber mass

10

planetary gear

11

ring gear

12

planetary gears

13

planet carrier

14

sun

20

braking means

22

coil carrier

23

Kitchen sink

24

connecting element

25

crankcase

28

anchor body

29

connecting element

30

belt

31

recess

32

recess

41

inner ring

42

outer ring

44

Mounting screw

45

roller bearing

46

roller bearing

48

connecting portion

49

flange

60

connecting flange

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 102007021233 A1 [0002, 0015, 0021]

Claims (10)

Crankshaft pulley for transmitting a torque between a crankshaft ( 4 ) and a belt drive, with at least one freewheel ( 6 ) and a transmission ( 10 ), characterized in that the transmission ( 10 ) in the crankshaft pulley ( 1 ) with a braking device ( 20 ) outside the crankshaft pulley ( 1 ) is combined. Crankshaft pulley according to claim 1, characterized in that the braking device ( 20 ) is designed as a frictional or positive electric brake. Crankshaft pulley according to one of the preceding claims, characterized in that the braking device ( 20 ) a movable anchor body ( 28 ) and a stationary coil carrier ( 22 ), the friction partners or form-fitting partners of the braking device ( 20 ). Crankshaft pulley according to claim 3, characterized in that the anchor body ( 28 ) and / or the coil carrier ( 22 ) of the braking device ( 20 ) radially outside a belt track ( 2 ) of the crankshaft pulley ( 1 are arranged / is. Crankshaft pulley according to claim 3 or 4, characterized in that the transmission ( 10 ) as a planetary gear with a ring gear ( 11 ) is executed, the non-rotatably with the anchor body ( 28 ) of the braking device ( 20 ) connected is. Crankshaft pulley according to one of claims 3 to 5, characterized in that the anchor body ( 28 ) in the de-energized state of a coil ( 23 ) of the braking device ( 20 ) in the axial direction of the bobbin ( 22 ) is spaced. Crankshaft pulley according to claim 6, characterized in that the anchor body ( 28 ) with the ring gear ( 11 ) in the energized state of the coil ( 23 ) is braked so that one or the belt track ( 2 ) of the crankshaft pulley ( 1 ) via the gearbox ( 10 ) with the crankshaft ( 4 ) is coupled. Crankshaft pulley according to claim 7, characterized in that the crankshaft pulley ( 1 ) a pulley freewheel ( 6 ) with an inner ring ( 41 ), which together with a planet carrier ( 13 ) of the planetary gear ( 10 ) rotatably with the crankshaft ( 4 ) and with an outer ring ( 42 ), which rotatably with the belt track ( 2 ) of the crankshaft pulley ( 1 ) connected is. Crankshaft pulley according to claim 8, characterized in that the outer ring ( 42 ) of the pulley freewheel ( 6 ) with a sun wheel ( 14 ) of the planetary gear ( 10 ) is combined. Crankshaft pulley according to one of claims 3 to 9, characterized in that the coil carrier ( 22 ) of the braking device ( 20 ) two recesses ( 31 . 32 ) for performing at least a portion of a belt ( 30 ) of the belt drive.

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