DE102005052386B3 - Hydrostatic locking clutch for use in multi-axle driven motor vehicle, has electrically controllable magnetic coil generating magnetic flux in chamber system, so that viscosity of magnetorheological fluid is changed - Google Patents

Abstract

The clutch has a chamber system (17) formed between sun gears (6, 7) and a planet gear (9), and a filling body that is partially filled with a magnetorheologic fluid. Channels are provided to connect two chamber areas with each other, where the areas have respective increased and decreased fluid pressures during rotation of two rotatable parts (3, 4). An electrically controllable magnetic coil (32) generates a magnetic flux in the chamber system via the fluid, so that viscosity of the magnetorheological fluid is changed.

Description

The The invention relates to a hydrostatic lockup clutch for coupling two mutually rotatable parts. The lockup clutch is doing this in a preferred application in a powertrain of a multi-axis driven Motor vehicle used, with a first drive shaft constantly driven and a second drive axle is drivingly connected thereto via the lockup clutch can be. Furthermore, the lock-up clutch between two Side shafts of a drive axle are arranged and for locking serve a differential gear.

From the DE 103 21 167 A1 is a hydrostatic coupling device for coupling and decoupling two relatively rotatable coupling parts known. The coupling device comprises a planetary differential with a sun gear, a ring gear, a land and a plurality of planet wheels, which are rotatably supported on the land and are in meshing engagement with the sun gear and the ring gear. The web carries a filling body which fills the spaces between the wheels, wherein a chamber system formed between the wheels and the filling body is filled with hydraulic fluid. There are connecting channels between - formed in relative rotation of the two coupling parts - areas of increased pressure and areas of reduced pressure provided in the chamber system. In the connecting channels adjustable throttle valves are arranged, which can inhibit the circulation of the hydraulic fluid, so that the two coupling parts are coupled together.

Out WO 2006/032295 A1 is a lock-up clutch for coupling a first Coupling part with a second coupling part rotatable relative thereto known. The lockup clutch comprises a gearing arrangement, the manner of a planetary gear is designed. The gear arrangement runs in a magnetorheological Fluid filled Chamber. By magnetizing the magnetorheoligische fluid is its viscosity changed so that one Locking action between the first coupling part and the second coupling part is produced.

From the US Pat. No. 6,811,007 B2 is a lock-up clutch in a transfer case for connecting a drive train known. For actuation, a hydraulically acting actuator, which is driven by an electromagnet, as well as a pump is provided, which continuously circulates magnetorheological fluid in a hydraulic circuit. To close the lock-up clutch, the electromagnet is activated, so that the viscosity of the magnetorheological fluid is increased. As a result, a dynamic pressure builds up on a diaphragm in the hydraulic circuit, which continues into a hydraulic chamber. A piston located there is acted upon by the hydraulic pressure and compresses the clutch discs of the clutch, whereby a blocking effect is achieved.

It Object of the present invention, a lock-up clutch with a to propose simple construction, which has a high power density, a good controllability and short activation times.

These The object is achieved by a Locking coupling for coupling two relative to each other about a common Rotary axis of rotatable parts, in particular for use in the drive train of a Motor vehicle, solved, comprising a planetary gear with a sun gear, a thereto coaxially arranged ring gear, a web element, at least one Planetary gear meshing with the sun gear and the ring gear is and opposite the web element is rotatably held, as well as at least one filling body, the in between the wheels formed spaces is arranged; a chamber system between the wheels and the formed at least one filler which is at least partially filled with magnetorheological fluid; wherein one of the mutually rotatable parts with a first element and the other of the mutually rotatable parts with a second element the following elements sun wheel, hollow wheel, web element is drive-connected; being channels provided at the meshing interventions between the wheels chamber areas, the relative increase in relative rotation of the two parts fluid pressure have, with chamber areas, the relative rotation of the two Parts having reduced fluid pressure to each other, connect together; and at least one controllable magnetic coil having a magnetic Flow over the fluid can produce in the chamber system, the viscosity of the magnetorheological Fluids changed becomes.

The advantage of the lock-up clutch according to the invention lies in a simple structure with simultaneously high power density. The at least one magnetic coil is electrically driven, so that the strength of the magnetic field can be set as desired by appropriate selection of the current or the voltage. This results in a high control accuracy and short activation times, so that it can be quickly responded to changing driving conditions. The configuration of the at least one magnetic coil, the planetary gear and the chamber system is adjusted so that upon excitation of the magnetic coil as uniform a magnetic field in the region of the channels or the chamber system is generated, so that a uniform viscosity of the fluid can be adjusted. there the web element, the ring gear, the at least one planetary gear and the sun gear are preferably made of ferromagnetic material. Activation of the solenoid produces a magnetic field passing through the chamber system which changes the viscosity of the magnetorheological fluid. The stronger the magnetic field, the greater the viscosity of the magnetorheological fluid and the greater the blocking effect of the lock-up clutch.

To In a preferred embodiment, the at least one magnetic coil held in an axially adjacent to the web element arranged stationary housing. Preferably, the web element is rotatably mounted relative to the housing, wherein the at least one magnetic coil in an annular recess of the bar element engages axially. For a uniform magnetization of the magnetorheological fluid, it is particularly favorable when the magnetic coil radially in the region of the at least one planetary gear is arranged. To strengthen the magnetization effect, you can also two solenoid coils may be provided, wherein the arranged in the web element is Rädersatz lies axially between the two magnetic coils.

In Concretization included the web element is a housing part and a lid member which are fixedly connected to each other, wherein the Ring gear opposite the housing part is freely rotatable. The channels are preferably arranged in the web element axially adjacent to the wheels, in each case between the wheels and the magnetic coil. The channels can be designed as holes in the web element. Alternatively, the channels also in the form of axial gaps between the planet wheels and be designed the web element, which is cheaper. It is favorable, though in an at least one planetary gear facing end face of the Guide elements Grooves for the passage of magnetorheological fluid are provided. Depending on whether one or two solenoid coils are used are, are channels provided only on one side or on both sides of the wheelset.

To a preferred embodiment the wheels, i.e. the sun gear, the ring gear and the at least one planetary gear, helically toothed, wherein the helical gears are designed such that the at least one planetary gear in relative rotation between the two coupling parts against a flat radial surface of the rod element starts. This especially applies to the embodiment with channels in the form of axial gaps; however, the wheels may also be in the embodiment helically toothed with holes be. In the execution with helical teeth becomes the torque produced by the magnetization of the fluid on the one hand and by the mechanical friction on the front sides of the Gearing parts resulting torque on the other hand superimposed.

Preferably is one of the two coupled parts with the web element rotation connected while the other of the two parts rotatably connected to the sun gear is. Of course you can but also one of the coupling parts rotatably connected to the ring gear which is then boxy should be designed. In Specification is the rotatably connected to the sun in part Formed a wave on which the web element by means of a Bearing is rotatably mounted. Preferably, the web element and the filler solid interconnected, in particular designed in one piece. For a uniform mass distribution with simultaneous coaxial alignment of ring gear and sun gear is it cheap three planet wheels and provide three fillers. It can but also a different number can be used.

Preferably a reservoir is provided for receiving magnetic rheological fluid, the connected to the chamber system. This may be due to temperature changes in the magnetorheological fluid resulting volume changes be compensated.

preferred embodiments The invention will be explained below with reference to the drawing. Here in shows

1 a locking coupling according to the invention in cross section;

2 a locking coupling according to the invention in a first embodiment, in which the section line II 1 is drawn;

3 a locking coupling according to the invention in a second embodiment in the section line II 1 is drawn;

The 1 and 2 , which will be described together below, show a lock-up clutch according to the invention 2 for coupling a first part 3 with a second part rotatable relative thereto 4 in the drive train of a motor vehicle, not shown here. The lockup clutch 2 serves to connect a secondary drive axle of the motor vehicle. For this, the first part 3 be rotatably connected via a constant velocity universal joint with the longitudinal drive shaft of the motor vehicle, while the second part 4 is rotatably connected to the drive pinion of a rear differential.

The lockup clutch 2 includes a planetary gear 5 with a sun wheel 6 , a ring gear arranged coaxially therewith 7 a web element 8th and several planet wheels 9 , The planet wheels 9 are on a cone 10 in the web element 8th rotatably held and comb with the sun gear 6 on the one hand and the ring gear 7 on the other hand. Here is the ring gear 7 basically freely rotatably supported relative to the web member and is about the plurality of planetary gears 9 centered on the axis of rotation A. The web element 8th comprises a cover part 12 that is integral with the first coupling part 3 is designed, and a hereby firmly connected housing part 13 in which the wheels 6 . 7 . 9 are included. For assembly, first the wheels 6 . 7 . 9 in the housing part 13 used, then the lid part 12 on the housing part 13 put on and by means of a weld 14 associated with this. The second coupling part 4 is designed in the form of a drive shaft, which by means of a spline 15 rotatably with the sun gear 6 is drive connected. The web element 8th is with its housing part 13 opposite to the sun wheel 6 rotatably connected drive shaft 4 by means of a rolling bearing 40 rotatably mounted and by means of sealants 11 sealed watertight. In the present case are the two coupling parts 3 . 4 with the web element 8th or the sun gear 6 rotatably connected. However, it is in principle an embodiment conceivable in which one of the two coupling parts 3 . 4 with the ring gear 7 rotatably connected.

The lockup clutch 2 further comprises several packing 16 that between the wheels 6 . 7 . 9 fill in as far as possible. The number of fillers 16 corresponds to the number of planet gears 9 , wherein in the present case a number of three are provided in each case. The packing 16 are fixed to the housing part 13 of the posture 8th connected; they are each in the radial direction of the ring gear 7 and the sun wheel 6 and in the circumferential direction of two adjacent planetary gears 9 limited. The peripheral lines of the packing 16 is in each case at a small distance from the top circle lines of the teeth of the ring gear 7 , two planet gears 9 and the sun wheel 6 defines and is composed of an outer circle section and three inner circle sections. In the web element 8th is a chamber system 17 formed out of overlapping cylinder pockets 18 for the sun wheel 6 and cylinder bags 19 for the planet wheels 9 as well as the annular gap 21 between ring gear 7 and packing 16 is formed. The chamber system 17 is at least largely filled with magnetorheological fluid. The gears 20 the planet wheels 9 are as usual with the external teeth 22 of the sun wheel 6 and the internal teeth 23 of the ring gear 7 engaged. Starting from the assumption of a left-hand driven top view in plan view 8th and a captured sun gear 6 the directions of rotation of the remaining parts are indicated by arrows. Due to the housing-like design of the bar element 8th with packing 16 Here is a pump housing for two gears 6 . 7 . 9 formed so that a promotion of enclosed in the housing magnetorheological fluid via connection channels 24 from the dotted print areas 25 in the suction areas shown hatched 26 can take place.

The connection channels 24 are in the form of gaps between faces 27 the planet wheels 9 and inner faces 28 of the posture 8th designed. To a defined flow of the magnetorheological fluid during relative rotation of the two coupling parts 3 . 4 to reach are in inner first faces 28 of the posture 8th to the interior open grooves 29 intended. The first faces 28 opposite second end faces 30 are designed as flat surfaces without any depressions. So the planetary gears 9 with relative rotation of the two coupling parts 3 . 4 against the flat faces 30 start, are the gears 20 . 22 . 23 designed as helical gears. So magnetorheological and mechanical torque are superimposed.

The lockup clutch 2 further comprises a controllable magnetic coil 32 which conducts a magnetic flux across the magnetorheological fluid in the chamber system 17 can generate, wherein the viscosity of the magnetorheological fluid is changed. The magnetic coil 32 is in an axially adjacent to the planetary gear 5 arranged standing housing 33 fixed and is connected to an electronic control unit, not shown here for controlling the driving dynamics of the motor vehicle via electrical lines 34 connected. The web element 8th is opposite the case 33 rotatably mounted, wherein the magnetic coil 32 in an annular recess 35 of the posture 8th engages axially. The between the magnetic coil 32 and the web element 8th formed gap is outwardly by means of sealants 36 sealed to prevent ingress of dirt. For a targeted magnetic flux through the chamber system 17 to generate, is the magnetic coil 32 coaxial to the axis of rotation A and in the diameter range of the planet gears 9 arranged. In this case, the axial distance between the magnetic coil 32 and the planetary gear 5 as small as possible. The web element 8th , the ring gear 7 , the planetary gears 9 and the sun wheel 6 are made of magnetic material, such as a ferritic steel. Due to the nature of the arrangement of the magnetic coil 32 and the material selection forms a toroidal magnetic field around the solenoid coil 32 out, that's the chamber system 17 detected and there can magnetize the magnetorheological fluid.

For relative rotation between the two coupling parts 3 . 4 is the magnetorheological fluid by rolling the gears 20 . 22 . 23 the wheels 6 . 7 . 9 repressed. Through this Pumping action is the magnetorheological fluid through the connecting channels 24 between the suction chambers 26 and the pressure chambers 25 promoted back and forth. This results in a low drag torque, which leads to a certain heat loss. In order to compensate for the resulting increase in volume of the fluid can in the shaft 4 a reservoir 37 be provided with the chamber system 17 is connected and in which the fluid through axial gaps between the planetary gears 9 or the sun gear 6 on the one hand and the web element 8th on the other hand can get.

In 3 a second embodiment of the lock clutch according to the invention is shown. This corresponds largely in terms of their structure and operation of those from 2 , to the description of which reference is made. In this case, the same components are provided with the same and modified components with one by one reference numerals. The lockup clutch 2 ' to 3 differs in that the connecting channels 24 ' are designed in the form of arranged in the housing part holes. In this case, the housing part 13 ' over the above embodiment, a larger axial extent. The connecting channels are each through two axial bores 38 , which open into the pressure and suction areas of the teeth, and one the axial bores 38 interconnecting radial bore 39 educated. The outer opening of the radial bore is after filling the chamber system 17 with magnetorheological fluid by means of a plug 31 locked. Through the connection of the pressure and the suction chambers, the fluid can during relative rotation between the two coupling parts 3 . 4 circulate. By activating the magnetic coil, the viscosity of the magnetorheological fluid is increased, whereby the blocking effect between the two coupling parts 3 . 4 is enlarged.

1

2

lock-up clutch

3

first part

4

second part

5

planetary gear

6

sun

7

ring gear

8th

web element

9

planet

10

spigot

11

sealant

12

cover part

13

housing part

14

Weld

15

spline

16

packing

17

chamber system

18

cylinder pocket

19

cylinder pocket

20

gearing

21

annular gap

22

gearing

23

gearing

24

connecting channel

25

pressure range

26

suction area

27

face

28

face

29

groove

30

face

31

Plug

32

solenoid

33

casing

34

electrical management

35

recess

36

sealant

37

reservoir

38

axial bore

39

radial bore

40

roller bearing

A

axis of rotation

Claims (15)

Locking coupling for coupling two parts rotatable relative to each other about a common axis of rotation (A) ( 3 . 4 ), in particular for use in the drive train of a motor vehicle, comprising a planetary gear ( 5 ) with a sun wheel ( 6 ), a coaxially arranged ring gear ( 7 ), a web element ( 8th ), at least one planetary gear ( 9 ), with the sun gear ( 6 ) and the ring gear ( 7 ) is in toothing engagement and with respect to the web element ( 8th ) is rotatably supported, and at least one filler ( 16 ) in between the wheels ( 6 . 7 . 9 ) is arranged, wherein a chamber system ( 17 ) between the wheels ( 6 . 7 . 9 ) and the at least one filling body ( 16 ) is formed, which is at least partially filled with magnetorheological fluid, wherein one of the mutually rotatable parts ( 3 . 4 ) with a first element and the other of the mutually rotatable parts ( 3 . 4 ) with a second element of the following elements sun gear ( 6 ), Ring gear ( 7 ), Web element ( 8th ) is drivingly connected, whereby channels ( 24 ) provided at the meshing intersections between the wheels ( 6 . 7 . 9 ) Chamber areas which, upon relative rotation of the two parts ( 3 . 4 ) to each other increased fluid pressure, with chamber areas, the relative rotation of the two parts ( 3 . 4 ) have mutually reduced fluid pressure, connect together, and at least one controllable magnetic coil ( 32 ), which conducts a magnetic flux via the fluid in the chamber system ( 17 ), wherein the viscosity of the magnetorheological fluid is changed. Locking coupling according to claim 1, characterized in that the magnetic coil ( 32 ) in an axially adjacent to the planetary gear ( 5 ) arranged standing housing ( 33 ) is held. Locking coupling according to claim 1 or 2, characterized in that the web element ( 8th ) opposite the housing ( 33 ) is rotatably mounted, wherein the magnetic coil ( 32 ) in an annular recess ( 35 ) of the bridge element ( 8th ) engages axially Locking coupling according to one of claims 1 to 3, characterized in that the magnetic coil ( 32 ) coaxial to the axis of rotation (A) and in the diameter range of the planet wheels ( 9 ) is arranged. Locking coupling according to one of claims 1 to 4, characterized in that the web element ( 8th ) the wheels ( 6 . 7 . 9 ) receiving housing part ( 13 ) and a cover part ( 12 ), which are firmly connected to each other. Locking coupling according to one of claims 1 to 5, characterized in that the channels ( 24 ) in the web element ( 8th ) axially adjacent to the wheels ( 6 . 7 . 9 ) are arranged. Locking coupling according to one of claims 1 to 6, characterized in that the channels ( 24 ) as holes ( 38 . 39 ) in the web element ( 8th ) are designed. Locking coupling according to one of claims 1 to 6, characterized in that the channels ( 24 ) in the form of gaps between faces ( 27 ) of the at least one planetary gear ( 9 ) and the web element ( 8th ) are designed. Locking coupling according to claim 8, characterized in that in at least one inner first end face ( 28 ) of the bridge element ( 8th ) Grooves ( 29 ) are provided for the passage of magnetorheological fluid. Locking coupling according to one of claims 1 to 9, characterized in that the wheels ( 6 . 7 . 9 ) are helically toothed, wherein the helical gears are designed such that the at least one planetary gear ( 9 ) with relative rotation between the two parts ( 3 . 4 ) against a plane radial surface ( 30 ) of the bridge element ( 8th ) starts. Locking coupling according to one of claims 1 to 10, characterized in that one of the two mutually rotatable parts ( 3 . 4 ) with the web element ( 8th ) is rotatably connected and the other of the two mutually rotatable parts ( 3 . 4 ) with the sun wheel ( 6 ) is rotatably connected. Locking coupling according to claim 11, characterized in that the sun gear ( 6 ) rotatably connected part ( 4 ) is designed in the form of a shaft on which the web element ( 8th ) by means of a warehouse ( 40 ) is rotatably mounted. Locking coupling according to one of claims 1 to 12, characterized in that the web element ( 8th ) and the filling bodies ( 16 ) are firmly connected to each other, in particular are designed in one piece. Locking coupling according to one of claims 1 to 13, characterized in that a reservoir ( 37 ) is provided for receiving magnethorheological fluid, which with the chamber system ( 17 ) connected is. Locking coupling according to one of claims 1 to 14, characterized in that the web element ( 8th ), the ring gear ( 7 ), the at least one planetary gear ( 9 ) and the sun wheel ( 6 ) are made of ferromagnetic material.