DE102011082647A1 - Crankshaft pulley - Google Patents

Abstract

The invention relates to a crankshaft belt pulley for transmitting a torque between a crankshaft and a belt drive, with a belt pulley, a transmission, a clutch and / or braking device and at least one freewheel. The crankshaft belt pulley is characterized in that the clutch and / or braking device is arranged radially outside the belt pulley.

Description

The invention relates to a crankshaft pulley for driving ancillaries of an internal combustion engine, which should be suitable for a starter generator operation, a stationary air conditioning, a pulse start and a boost. Furthermore, the crankshaft pulley includes an integrated pulley damper, a detachable planetary gear for the start of the engine by means of the starter generator and a Kurbelwellentilger for eradicating harmful to the crankshaft vibrations.

The known arrangements of this type required components in different pulleys, additional axial space, a larger pulley diameter or have to dispense with certain of these functionalities. Therefore, according to the prior art, several expensive and space-consuming pulleys, an increased axial space or an enlarged belt drive to maintain the required gear ratios with larger crankshaft pulley needed. Alternatively, certain functionalities must be avoided.

The object of the present invention is to avoid the disadvantages mentioned, so a compact arrangement of the components pulley decoupler for the stationary climate mode with the possibility of pulse start from rotating belt drive, starter generator gearbox, pulley damper and Kurbelwellentilger for integration in the crankshaft pulley with largely axial space neutrality and to provide an unchanged pulley diameter as compared to conventional pulleys.

This object is achieved by the following measures: The inner ring of the pulley freewheel is connected by means of one or more mounting screws with the crankshaft of the internal combustion engine. On this, the pulley is mounted, for example by means of two bearings. The parallel pulley freewheel is not designed to lift by centrifugal force. The inner ring of the pulley freewheel is connected to the planet carrier of a planetary gear designed pulley transmission. One or more mounted on the planet carrier planetary gears mesh with a ring gear, on which the brake disc of a disc brake is arranged radially outside of the pulley. The caliper or preferably a plurality of evenly distributed on the circumference calipers are also located radially outside the pulley. They are fixed to the housing, for example, mounted on the crankcase or on the crankcase cover of the internal combustion engine. By using a plurality of evenly distributed on the circumference calipers no or only a very small lateral force support due to the friction force on the brake disc is required.

The sun gear of the planetary gear is arranged pulley fixed. On the crankshaft fixed planet carrier of Kurbelwellentilger is arranged by means of a conventional rubber track. Alternatively, a Stahlfedertilger be arranged in the space between the planetary gears.

Due to the normally small distance of the belt track to the crankcase or cover, the calipers are preferably designed as Faustsattel, where the brake actuating actuator, for example in the form of a hydraulic piston, an electric drive or a mechanical actuator, locally so in the axial region the belt track protrudes, that no collision with the beltrums arises. The other side of the caliper can thus be made flat, so that the belt track does not have to be located axially further away from the crankcase than in prior art pulleys.

The caliper (s) is / are preferably arranged in the axial direction overlapping the pulley. Axial means in the direction or parallel to a rotation axis of the crankshaft. Radial means transverse to the axis of rotation of the crankshaft. The caliper or the calipers is or are particularly preferably arranged radially outside and in the axial direction overlapping to the pulley. As a result, the available space can be optimally utilized.

The caliper (s) are preferably arranged in the radial direction inside or outside a belt hub. The belt wrap partially wraps around the pulley. At least one caliper is disposed radially within the belt. Two calipers may also be arranged diametrically so that a first caliper is arranged in the radial direction inside and a second caliper in the radial direction outside the belt.

An actuator of the coupling and / or braking device is preferably arranged in the axial direction overlapping the pulley. The actuator preferably has a smaller extent in the axial direction than the pulley. The actuator is particularly preferably arranged radially outside the pulley so that the actuator does not project beyond the pulley in the axial direction.

To start the internal combustion engine, the normally open disc brake is closed. As a result, the torque applied to the pulley via the starter generator and belt is transmitted to the sun gear of the planetary gear. Since the ring gear is braked fixed to the housing, an increased torque is generated on the planet carrier, which sets the crankshaft of the engine to start in rotation. The pulley freewheel is overhauled in this operating state in the freewheeling direction.

After the start of the engine eliminates the operation of the disc brake so that it opens and no torque can be transmitted. Now the crankshaft drives its torque on the pulley for driving the belt drive and the generator via the pulley freewheel closing in this torque direction with positive momentary impulses (in the drive direction). With negative torque surges, the belt drive can overtake the crankshaft due to its inertia through the pulley freewheel, which illustrates the function of the pulley cushioning and service life increase of belts and aggregates connected thereto. Since the planetary gear is decoupled at the ring gear due to the open disc brake, no torque is transmitted to the planet carrier, only the ring gear rotates during the Überholphasen the pulley freewheel according to the planetary translation load-free backwards to the pulley rotation.

When the engine is stationary and the disc brake is not actuated, the pulley can rotate freely in the overrunning direction of the freewheel. As a result, the starter generator can drive the air conditioning compressor connected to the belt drive while the crankshaft is stationary, thereby demonstrating the function of "stationary air conditioning". In this operating condition, the ring gear of the planetary gear is rotated without load (in the opposite direction to the pulley).

If the internal combustion engine is to be started during stationary air conditioning ("pulse start"), the frictional disc brake is actuated and closed when the pulley rotates, thereby starting the internal combustion engine. Braking the pulley to close the disc brake is not required. A sufficient wear reserve of the brake pads is possible by the axially on one side very short design of the calipers as Faustsattel. The operating state "change of mind" (shutdown of the internal combustion engine and restart before the crankshaft comes to a standstill) can thus be displayed.

The freewheel can be preferably switched in its reverse direction or alternatively by a parallel locking mechanism, for. B. be bridged by a positive jaw clutch between the outer and inner ring. As a result, with the disc brake open, the torque applied by the starter generator to the pulley can be transmitted directly to the crankshaft via the switched-over freewheel or the locking device. This operating state is referred to as a 1: 1 boost and allows the support of the internal combustion engine by the torque of the starter generator.

The positive claw coupling can be designed for example as a ball coupling. Here, a cone is axially displaced upon actuation, the more in holes z. As the freewheel inner ring arranged balls pushes outwards, which in recesses z. B. in the freewheel outer ring and thus produce a positive connection of the two components.

Alternatively, the bridging can also be designed as an axially actuated dog clutch. The axial actuation of the bridge itself can each mechanically z. B. by means of a Bowden cable or alternatively by means of a hydraulic piston.

• – Dämpfung der Kurbelwellenschwingungen im Generatorbetrieb mittels Freilauf;
• – Gestaltung dieses Freilaufs als nicht durch Fliehkraft abhebend;
• – Planetengetriebe zur Drehmomenterhöhung zum (Kalt-)Start des Verbrennungsmotors;
• – reibschlüssige Scheibenbremse zum Festbremsen des Hohlrads;
• – Positionierung der Scheibenbremse radial außerhalb der Riemenscheibe zwischen Kurbelgehäuse und Zahnriemen;
• – hohlradfeste Anordnung der Bremsscheibe der Scheibenbremse;
• – gehäusefeste Anordnung des oder der Bremssättel der Scheibenbremse;
• – alternativ gleichmäßige Verteilung mehrerer Bremssättel am Umfang der Bremsscheibe (Querkraftfreiheit);
• – alternativ Ausgestaltung der Bremssättel als Faustsättel (Schwimmsättel);
• – Ausrichtung der Bremsbetätigungsaktors (Hydraulikkolben, E-Antrieb, mechanischer Antrieb) vom Kurbelgehäuse abgewandt zwischen den Trums des Riemens;
• – Verwendung eines umschaltbaren Freilaufs zum 1:1-Boost (oder -Verbrennerstart);
• – Gestaltung des vorzugsweise umschaltbaren Freilaufs vorzugsweise mit unbetätigter Sperrrichtung für Generatorbetrieb;
• – alternativ Verwendung einer parallel zum nicht umschaltbaren Freilauf angeordneten Überbrückungsmöglichkeit des Freilaufs mittels formschlüssiger Kupplung zum 1:1-Boost (oder Verbrennerstart);
• – Gestaltung der Überbrückungsmöglichkeit vorzugsweise als „normal geöffnet”;

The described crankshaft pulley is characterized among other things by the following features:

• - Attenuation of the crankshaft vibrations in generator mode by means of freewheeling;
• - Design of this freewheel as not lifted by centrifugal force;
• - Planetary gear for torque increase for (cold) start of the engine;
• - Frictional disc brake for stalling the ring gear;
• - Positioning the disc brake radially outside the pulley between the crankcase and timing belt;
• - Hohlradfeste arrangement of the disc brake disc;
• - Housing fixed arrangement of the brake caliper (s) of the disc brake;
• - Alternatively even distribution of several calipers on the circumference of the brake disc (lateral force freedom);
• - Alternatively embodiment of the calipers as Faustsattel (floating calipers);
• - Orientation of Bremsbetätigungsaktors (hydraulic piston, electric drive, mechanical drive) facing away from the crankcase between the runs of the belt;
• - Using a switchable freewheel for 1: 1 boost (or burner start);
• - Design of preferably reversible freewheel preferably with unconfirmed reverse direction for generator operation;
• - Alternatively use a parallel to the non-reversible freewheel arranged bridging possibility of the freewheel by means of positive clutch for 1: 1 boost (or combustion start);
• - design of the bridging option preferably as "normally open";

In the drawings variants of the invention are shown. Show it

1 : A schematic diagram of the crankshaft pulley according to the invention with switchable freewheel in a sectional view;

2 : A schematic diagram of the crankshaft pulley according to the invention with bridgeable freewheel in a sectional view;

3 : a schematic diagram of the crankshaft pulley according to the invention in a plan view;

4 a sectional view of the crankshaft pulley according to the invention with bridgeable freewheel by means of ball mechanism;

5 a sectional view of the crankshaft pulley according to the invention with bridgeable freewheel by means of dog clutch;

In the 1 to 5 is a crankshaft pulley 1 shown in various views and according to various embodiments. The same or similar parts are provided with the same reference numerals. The crankshaft pulley 1 includes at least one belt track 40 Also referred to as a pulley, for example, it serves to couple a belt of a belt drive to a belt starter generator and / or at least one accessory, such as an air conditioning compressor.

The crankshaft pulley 1 is in a drive train of a motor vehicle, as for example in the German Offenlegungsschrift DE 10 2007 021 233 A1 is disclosed by means of a mounting screw 25 (please refer 4 and 5 ) on a crankshaft 2 attached, which is about a rotation axis 26 is rotatable. The motor vehicle may be a hybrid vehicle with an internal combustion engine and an electric machine.

The crankshaft pulley 1 is a braking device 28 associated with a floating caliper 3 or caliper 20 , a brake piston 4 , Brake pads 5 . 6 and a brake disc 7 includes. In the crankshaft pulley 1 are a planetary gear 21 , an absorber device with a absorber 22 and a freewheel 23 ; 24 . 24a . 24b integrated. The freewheel 23 is reversible. The freewheels 24 . 24a . 24b are bridgeable.

The pulley 1 includes a radial flange 30 who the belt trace 40 rotatably with a sun gear 32 of the transmission 21 connects, which is designed as a planetary gear. The planetary gear 21 includes in addition to the sun gear 32 planetary gears 34 that works both with the sun gear 32 as well as with a ring gear 36 are engaged. The planet wheels 34 are on a planet carrier 35 rotatably mounted. On the planet carrier in turn is a damper mass of the absorber with the interposition of a rubber track 22 appropriate.

The ring gear 36 is non-rotatable with the brake disc 7 the braking device 28 connected. The planetary gear 21 with the sun wheel 32 , the planet wheels 34 and the ring gear 36 is through dividing walls 38 . 39 capsuled. The dividing walls 38 . 39 extend substantially in the radial direction and serve to unwanted leakage of lubricant, which is used to lubricate the planetary gear 21 serves, from the crankshaft pulley 1 to prevent. The dividing walls 38 . 39 are for example designed as sheet metal parts. Radially inside are between the dividing walls 38 . 39 and relative to rotating parts provided sealing means, such as shaft seals.

The brake disc 7 extends from the ring gear 36 of the planetary gear 21 radially outward, where they are between the brake pads 5 . 6 the braking device 28 can be clamped. The brake pads 5 . 6 are above the brake piston 4 in the floating saddle 3 or caliper 20 actuated. The floating caliper 3 or caliper 20 is with the help of a storage 42 floating on a crankcase 44 stored. Due to the floating bearing is the caliper 3 . 20 rotatably with the crankcase 44 connected, but can shift relative to this limited in the axial direction.

In the illustrated state, the braking device 28 open, that is, the brake pads 5 . 6 are from the brake disc 7 spaced. When the brake piston 4 , for example hydraulically, is actuated, then it moves on the brake pads 5 . 6 to the brake disc 7 between the brake pads 5 . 6 pinch. Then the brake disc 7 rotatably with the crankcase 44 connected, that is, the brake disc 7 stand still.

In 3 can be seen in a plan view of the crankshaft pulley 1 that diametrically to the caliper 3 another caliper 53 can be arranged. Here is the caliper 3 inside a belt 55 arranged the the Crankshaft pulley 1 or belt track 40 partially surrounds. The caliper 53 is outside the beltroom 55 arranged.

The freewheel 24 ; 24a ; 24b includes an inner ring 60 , which rotates with the crankshaft 2 connected is. The inner ring 60 also serves to support the sun gear 32 of the planetary gear 21 with the help of two rolling bearings 61 . 62 , The freewheel 24 ; 24a ; 24b further includes an outer ring 64 ; 74 , which rotates with the sun gear 32 of the planetary gear 21 connected is.

Between the inner ring 60 and the outer ring 64 ; 74 are freewheel bodies 65 ; 75 arranged. The inner ring 60 of the pulley freewheel 24 ; 24a ; 24b is with the planet carrier 35 connected, in turn, rotationally fixed to the crankshaft 2 connected is. The planet carrier 35 extends from the mounting screw 25 stepped radially outward. Radially outside are on the planet carrier 35 the planet wheels 34 rotatably mounted.

The freewheel 24a the in 4 shown crankshaft pulley 1 is through a clutch 70 operable as a ball coupling with balls 12 Running with ball ramps 13 interact. When the clutch 70 over a Bowden cable 11 is pressed, then move the balls 12 radially outwardly in recesses into the radially inner to the outer ring 64 of the freewheel 24a are provided.

Through the balls 12 becomes a twisting of the outer ring 64 relative to the inner ring 60 prevents, so the freewheel 24a locked or overridden. The movement of the balls 12 radially outward is through the ball ramp 13 causes. By a return spring is the ball ramp 13 again against the pulling direction of the Bowden cable 11 (in 4 to the right) moves back to the freewheel 24a to unlock or release.

In the 5 illustrated crankshaft pulley 1 includes a dog clutch 14 that serves the freewheel 24b to bridge or block. The claw clutch 14 includes claws 71 which has a non-rotatable connection with an outer ring 74 of the freewheel 24b enable. In addition, the dog clutch 14 via an axial toothing 72 rotatably with the inner ring 60 of the freewheel 24b connectable. Between the inner ring 60 and the outer ring 74 of the freewheel 24b are freewheel bodies 75 arranged.

The claw clutch 14 is biased by a return spring in its illustrated position, in which the outer ring 74 relative to the inner ring 60 of the freewheel 24b can twist. When the dog clutch 14 via a hydraulic piston 9 is pressed, then the outer ring 74 of the freewheel 24b over the claws 71 and the axial toothing 72 rotatably with the inner ring 60 connected to the freewheel 24b to bridge or block. That for actuating the hydraulic piston 9 required hydraulic medium is via a hydraulic line 8th fed.

In the in the 4 and 5 illustrated embodiments, the Bowden cable attacks 11 or the hydraulic line 8th central to the center of the crankshaft pulley 1 on, on the crankshaft 2 opposite side. The Bowden cable 11 or the hydraulic line 8th extends in the crankshaft pulley 1 in the direction of the axis of rotation 26 on the mounting screw 25 to.

LIST OF REFERENCE NUMBERS

1

pulley

2

crankshaft

3

floating caliper

4

brake pistons

5

brake lining

6

brake lining

7

brake disc

8th

hydraulic line

9

hydraulic pistons

10

belt strand

11

Bowden

12

Bullet

13

ball ramp

14

claw clutch

20

caliper

21

planetary gear

22

absorber

23

Freewheel, switchable

24, 24a, 24b

Freewheel, bridgeable

25

Mounting screw

26

axis of rotation

28

braking means

30

radial flange

32

sun

34

planetary gears

35

planet

36

ring gear

38

partition wall

39

partition wall

40

belt track

42

storage

44

crankcase

53

caliper

55

belt strand

60

inner ring

61

roller bearing

62

roller bearing

64

outer ring

65

Freewheel body

70

clutch

71

steal

72

axial toothing

74

outer ring

75

Freewheel body

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 [0025]

Claims (10)

Crankshaft pulley for transmitting a torque between a crankshaft ( 2 ) and a belt drive, with a pulley ( 1 ), a transmission ( 21 ), a clutch and / or brake device ( 28 ) and at least one freewheel ( 24 ), characterized in that the coupling and / or braking device ( 28 ) substantially radially outside the pulley ( 1 ) is arranged. Crankshaft pulley according to claim 1, characterized in that the coupling and / or braking device ( 28 ) is a disc brake. Crankshaft pulley according to claim 2, characterized in that the disc brake by means of a rotationally fixed relative to a housing ( 44 ) mounted caliper ( 3 . 20 ) is operable. Crankshaft pulley according to claim 3, characterized in that a plurality of calipers ( 3 . 53 ) are arranged along the circumference of the disc brake. Crankshaft pulley according to claim 3 or 4, characterized in that the caliper ( 20 ) / the calipers ( 3 . 53 ) in the axial direction overlapping to the pulley ( 1 ) is / are arranged. Crankshaft pulley according to one of claims 3 to 5, characterized in that the brake caliper ( 20 ) / the calipers ( 3 . 53 ) in the radial direction inside or outside a belt ( 55 ) is / are arranged. Crankshaft pulley according to one of the preceding claims, characterized in that the coupling and / or braking device ( 28 ) a brake disc ( 7 ) which is rotationally fixed with a ring gear ( 36 ) of the transmission ( 21 ) connected is. Crankshaft pulley according to one of the preceding claims, characterized in that the freewheel ( 24 . 24a . 24b ) can be bridged or switched. Crankshaft pulley according to claim 8, characterized in that the freewheel ( 24a . 24b ) by means of a coupling ( 70 ; 14 ) is bridgeable. Crankshaft pulley according to one of the preceding claims, characterized in that an actuator ( 4 ) of the coupling and / or braking device ( 28 ) in the axial direction overlapping to the pulley ( 1 ) is arranged.

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