DE102009036986A1 - Differential gear for motor vehicle, has differential gear housing provided with axle drive gear, where part of housing is provided with flange and locked at axle drive gear in another part of housing by flange - Google Patents

Abstract

The gear (1) has a differential gear housing (7) provided with an integrated axle drive gear (6). A part (11) of the differential gear housing is provided with a flange (13) and locked at the axle drive gear in another part (10) of the housing by the flange. The axle drive gear and the flange comprising openings (14) for a bolted joint. The former part of the housing is designed as a differential cage (12), and the latter part of the housing is formed in such a manner that it includes a bearing area (17) beside the axle drive gear, where the former part of the housing has a bearing area (16). The part of the housing is formed as a casting component, and the other part of the housing is formed as a forged steel component.

Description

The The invention relates to a differential, in particular for a motor vehicle, wherein the differential housing an integrated trained Achsantriebsrad includes.

differential in motor vehicles come as axle differential to compensate for different Speeds of the two wheels of a driven axle or as a center differential or transfer case to compensate for different average speeds of two driven axles for application. These are in a differential housing or differential gear housing several differential gears and arranged on output shafts driven wheels or axle bevel wheels rotatably mounted. The torque is from a drive motor and a downstream transmission via a Axle drive wheel on the differential case and from there on the balancing and driven wheels or output shafts transmitted to the vehicle wheels.

In known differential gear housings usually a separate Achsantriebsrad is assembled by means of a rivet or screw with the differential or differential carrier. For this purpose, both the Achsantriebsrad and the compensating basket or associated with flanges with webs, which have holes provided, which serve to connect with rivets or screws of the components. In the DE 199 05 306 A1 For example, a differential gear is described which comprises three parts, namely a planetary carrier, extending over the mounting hole of the planet carrier flange and a lid. The ends of the planet carrier and the flange are connected to each other by means of a screw with the Achsantriebsrad mehrstückig. The required flange edges and screw connections lead to a rather bulky design. If such a differential gear has only two differential gears, the entire transmission must be dimensioned relatively large due to the relatively strong point load. Four differential gears lead to a cross over a bolt lock.

It is also known to weld the axle drive wheel to the balance basket or to connect it by means of a forging process. In the DE 102 60 170 A1 It is proposed to form the balance basket and the final drive wheel as a one-piece molded cast component of a ductile cast iron. It is a one-piece cast differential housing.

In addition, from the DE 102 44 395 A1 a differential gear with a parking lock function and a method for its production is known, wherein the differential housing, including the Achsantriebsrades and the parking lock toothing is formed by forming a single component. The forged differential housing consists of a main body and a lid, which is welded to the main body. Covered by the lid opening is used for mounting the differential gears. The manufacturing process is a forming, wherein the entire component is then carbonitrided and tempered or inductively hardened. Due to the welding process to close the lid, the manufacturing process is not yet optimal.

outgoing This is the object of the invention is a compact differential to create that is to produce with little effort.

These The object is achieved with the features of claim 1. Advantageous embodiments can be found in the subclaims.

Of the Invention is based on the idea that - starting from a differential housing with an integrated molded axle drive wheel - a first part of the differential housing is provided with a flange by means of which it is connected to a second Part and that is locked directly to the Achsantriebsrad or arrested. For this purpose, the Achsantriebsrad and also the flange of the other part openings for a connection - in particular screw - on.

On this way a split, open, differential is created, because of a sufficient mounting opening more can accommodate as two differential gears and yet a compact Ensures space with low connection costs.

By doing the individual components can take over several functions the number of components can be reduced. The connection of the housing parts takes place with low production or connection costs, as over only one connecting means, in particular a row of screws, only two Parts (Achsantriebsrad and flange) are to be connected. The load on the lanyard goes back, leaving the individual Screw can be designed more cost-effective. So can For example, with a screw whose weight is reduced and its length be shortened.

Of the The first part of the housing is essentially a compensation basket trained and bolted to the axle (second part), wherein the second part at the same time housing part, the Achsantriebsrad with Running gears and bearings forms. The second housing part takes over In addition, the closing function after assembly.

To a development of the invention is proposed that also the first part, d. H. the compensation basket has a bearing, wherein at least one of the two bearing points with means for conducting and / or distributing a fluid, here oil, is provided. These are in particular designed as a swirl groove. This swirl groove serves to fluid by relative rotation of the or the housing part / e to The thus in sliding connection gears, here in particular along the shift of the gears of shaft bevel gears, to guide along the plain bearing. Such swirl grooves preferably run helical or spiral.

Around Lubricant, especially oil, to the conductive agents, preferably the swirl grooves, it is especially suggested that this in conjunction with oil windows and scoop grooves or ribs. Oil penetrates from the outside the windows in the housing and is adjacent arranged Schöpfrillen targeted to the guide means or swirl grooves directed. In the second housing part, these windows and Scoop grooves in the final drive wheel - radial to Bearing with the guide means or swirl grooves - introduced. In the first housing part are corresponding windows in the compensation basket provided, with the scoop grooves also in the compensation basket between the windows and the guide means or swirl grooves of the bearing extend. The promotion of the fluid, especially oil, is further characterized by profiling in the window walls as well as supported by slings. Stop these the oil at rotating housing parts and conduct it in the cupping grooves. Due to the proposed features of the oil windows, Scoop grooves, slings and guide means or swirl grooves a secure lubrication of the bearings is achieved.

The Axle-shaft gears are in particular shaft-shaft gears formed by the bearing points formed by the housing be recorded. In this way, a good leadership quality created for the drive shafts, the differential gear then overall can be made compact.

To A preferred embodiment of the invention is proposed that the second part is a steel component, in particular a forged one Steel component, is. This results in weight advantages with good Strength properties. Optimal sliding properties between the Housing part and the gears, in particular the Shaft bevel gears, which are also made of steel are due to the preferred oil lubrication due set the swirl grooves.

Of the Modular design of the differential gear allows executions with two or four balancing wheels as well as for Front and all-wheel applications. Four differential gears will be in particular locked by a bolt cross piece. Compared to a differential with only two differential gears can a larger torque can be transmitted. In transmission the same torque, the differential can be reduced become. It will create a complex differential gear, too associated with the advantage that the pivot point of the joint of the motor-distant drive shaft in a front-wheel drive further in the direction Center of the vehicle can be moved. The invention Differential gear is dimensioned so that it also in vehicle designs can be used with a smaller center distance.

The Invention will now be closer by means of the following figures explained. Show here

1 a sectional view of a differential gear according to the invention;

2a , b are two views of the second part of the housing with bearing and integrated trained Achsantriebsrad, seen from the front and back respectively;

3 a side view of the second part of the housing;

4 Cut BB the 3 ;

5a , b are two views of the first part of the housing (compensation basket), seen from the front and rear, respectively;

6 a cross-sectional view of the first part of the housing.

7 a section of a sectional view of the sealing cap 1 ,

1 shows the differential gear according to the invention 1 , here in the installed state for a transversely mounted front-wheel drive. That over a drive shaft 2 a transmission gear - indicated here by parts of gears 3 and a synchronizer 4 - Coming torque will be over with the shaft 2 connected shootlet 5 on an axle drive wheel 6 and from there to the differential housing 7 and then via the - if necessary. rotating differential gears 8a -D - on the axle wheels 9a , b and the inserted propeller shafts (not shown).

The differential housing 7 is constructed in two parts. It includes a second part 10 , the integrated with the housing trained Achsantriebsrad 6 having. The first part 11 who is essentially the compensation basket 12 forms, is with a along the Achsantriebsrades 6 extend the flange 13 Mistake. Both the final drive wheel 6 as well as the flange 13 have aligned openings 14 for receiving screws 15a , b on, showing the two components ( 10 . 11 ) connect with each other directly. The respective openings 14 in the final drive gear are threaded.

Both the first and the second part ( 11 . 10 ) of the differential housing 7 are provided along the stub axle with a neck or a cylindrical extension, which serves as a bearing 16 . 17 for the axle bevel gears designed as a shaft bevel gear 9a , b serves. The first part 11 or compensation basket takes four differential gears 8a -D and the second shaft bevel gear 9b on. These four differential gears 8a -D are over a bolt cross piece 18 locked, with the bolts 19 by means of pins 20 in the case 7 are held. The differential housing 7 is by - here two - tapered roller bearings 21 stored in the gear unit. Other storage concepts (for example, the use of angular contact ball bearings, fixed / floating) can be combined with the differential gear.

The differential gear according to the invention is designed so that it in particular what the lubrication of the shaft bevel gears 9a . 9b As far as benefits are concerned. This will be done with the help of 2 to 6 described and illustrated in detail.

The second part 10 the housing also forms the housing part, the Achsantriebsrad 6 with running teeth 22 as well as a depository - here 17 -, what from the 2a , b to 4 becomes clear. Radial, adjacent to the deposit 17 , are in the final drive wheel 6 - here four - oil windows 23 introduced, which are formed substantially as a slot. in the interior of the housing facing side of the second part are radially scoop grooves 24 in the form of grooves in the Achsantriebsrad 6 introduced (cf. 2 B ). On each side of the windows 23 are lifting gear 25 or limiting means provided in the form of elevations. These ridges stop the oil entering from the outside and assist in directing them into the radially inwardly extending scoop grooves 24 , These scoop grooves 24 bordering on a helical or spiraling means for conducting oil, here a swirl groove 26 , which is incorporated in the bearing surface. The twist groove 26 extends from the inside of the body to the outside, to the end of the bearing 17 , away (see in particular 4 ). Oil now passes through the windows 23 in the housing part. It gets over the scoop grooves 24 inside to the swirl groove 26 and from there along the entire bearing surface promoted. This guarantees adequate lubrication between the bearing 17 and the Schaftachswellenrad. In particular, when the second part of the housing is made as a steel component, ensures the helical swirl groove 26 sufficient lubrication and lubrication of Schaftachswellenrades 9a , which is also made of steel. The swirl groove for oil supply is made in particular by machining.

The 5a , Federation 6 clarify details of the first part 11 the differential gear housing or the balance basket 12 , This has the flange 13 with the openings 14 for the screw on and goes over into an intermediate part 27 , the four bolt bearings 28 and four oil windows 29 - Distributed over the circumference arranged - has. In the subsequent rejuvenating part of the balance basket 12 extend from the windows 29 also scoop grooves 30 or scooping or scooping ribs attached to a swirl groove 33 in the depository 16 end up. The scoop grooves 30 are between the pin bearings 28 at the windows 29 arranged. In the walls of the windows 29 are increased profilings 31 or raised in the sense of humps for directional oil transport incorporated. These borders into an annular Schöpfrille 32 , of which - here - four scoop grooves 30 to the swirl groove 33 extend. In the ring-shaped Schöpfrille 32 are each adjacent to the star-shaped converging Schöpf grooves 32 further oil stopper 34 Increases are provided, which slow down or stop the oil at this point and directed into the scoop grooves 32 and thus into the swirl groove 33 and to the depository 16 conduct. The twist groove 33 runs in the embodiment shown approximately to the middle of the bearing 16 (see in particular 6 ).

following will discuss the manufacture of components and their assembly.

The second, formed with the final drive, housing part is not like the first housing part a casting, but is preferably made as a steel component. In particular, this component is subjected to a hardening process at the end of its production. In order to avoid deformations, it is advantageous to use the second part 10 with axle drive wheel 6 Hardening in a hardening press In addition, the component is designed with relatively constant wall thicknesses and with openings. The base material of the forging is determined by the strength requirements of the running gear. To increase the strength of the running gear, the entire component is advantageously carbonitrided and annealed or inductively hardened. The hardness specifications depend on the requirements of the toothing calculation. A hardness of 680 HV 30; Eht 550 = 0.7 + 0.3 is preferably adjusted. Preferred base materials depending on the hardening process are 16MnCr5, 20MnCr5, and 17NiCrMo6 or 42CrMo4 or the like.

When mounting four Ausgleichsrä of the 8a -D by means of the bolt cross piece 18 in the first housing part 11 and a Schaftkegelrad mounted. The second housing part 10 with the further shaft bevel gear is set and by means of screws 15a , b connected. About radial shaft seals 35 on the shaft bevel gears and over sealing caps or cap 36 becomes the transmission 1 sealed to the outside oil-tight. Details of the sealing cap 36 are in the 7 shown. Such a sealing cap has the particular advantage that it allows a gentle pressure equalization when inserting the propeller shaft (in the sense of a membrane function). For this purpose, it comprises a steel body 37 with central hole 38 (Hole in the steel core) and a plastic sheath 39 , When plugging in the inner or cardan shaft, a possible build-up of air pressure can be reduced. The sealing cap always stays in its position and can not be pushed out undesirably. The gearbox is then delivered ready for installation to the vehicle factory for installation. There, the vehicle-side PTO shafts are inserted into the transmission.

All in all provides the proposed Baumraumoptimierte construction of the differential gear for low flexion angle of the cardan shafts and thus for low friction losses. In addition, the lubrication of the sliding bearing points secured in an advantageous manner. It will be an oil-tight Transmission with internal connection for the axle or cardan shafts and Modular design as 2- or 4-planetary differential or differential compensation provided.

LIST OF REFERENCE NUMBERS

1

differential

2

drive shaft

3

gears

4

synchronizer

5

output gear

6

axle drive

7

Differential case

8a-d

differential gears

9a b

axle wheels (here shaft bevel gear)

10

second part

11

first part

12

balance basket

13

flange

14

openings

15a, b

screw

16

depository

17

depository

18

Bolt crosspiece

19

bolt

20

pen

21

roller bearing

22

running gear

23

window (Oil window)

24

adding grooves

25

slings (Increase)

26

medium for conducting a fluid, swirl groove

27

intermediate part

28

pin suspension

29

window (Oil window)

30

adding grooves

31

profiling

32

annular educated Schöpfrille

33

medium for conducting a fluid, swirl groove

34

slings

35

Radial shaft seals

36

sealing caps

37

steel body

38

drilling

39

Plastic sheathing

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 19905306 A1 [0003]
• DE 10260170 A1 [0004]
• - DE 10244395 A1 [0005]

Claims (13)

Differential ( 1 ), in particular for a motor vehicle, comprising a differential housing ( 7 ) with an integrated axle drive wheel ( 6 ), characterized in that a first part ( 11 ) of the differential housing with a flange ( 13 ), by means of which it is attached to a second part ( 10 ) of the housing, the Achsantriebsrad ( 6 ), on the axle drive wheel ( 6 ) can be locked or locked. Differential according to claim 1, characterized in that the final drive wheel ( 6 ) and the flange ( 13 ) Openings ( 14 ) for a connection, in particular screw connection having. Differential according to claim 1 or 2, characterized in that the first part ( 11 ) of the housing as compensation basket ( 12 ) and that the second part ( 10 ) is designed so that it next to the Achsantriebsrad ( 6 ) also a depository ( 17 ). Differential according to one of claims 1 to 3, characterized in that the first part ( 11 ) a depository ( 16 ), the storage location ( 17 ) of the second part ( 10 ) and / or the depository ( 16 ) of the first part ( 11 ) with means for conducting a fluid, in particular oil, preferably with a swirl groove (US Pat. 26 . 35 ) is provided. Differential according to one of claims 1 to 4, characterized in that the means for guiding the fluid, preferably the swirl groove ( 26 . 35 ), helical or helical. Differential according to one of claims 1 to 5, characterized in that adjacent to the means for guiding the fluid, preferably to the swirl groove ( 26 . 35 ), at least one scoop groove ( 24 . 33 ) arranged through at least one window ( 23 . 29 ) penetrating into the gear fluid, in particular oil, directed to the guide means, preferably the swirl groove ( 26 . 35 ), directs. Differential according to claim 6, characterized in that in the second part ( 10 ) the at least one window ( 29 ) and the at least one scoop groove ( 24 ) radially in the final drive wheel ( 6 ) adjacent to the depository ( 17 ) are arranged. Differential according to claim 6 or 7, characterized in that in the first part ( 11 ) the at least one window ( 29 ) in the compensation basket ( 12 ) is arranged. Differential according to one of claims 6 to 8, characterized in that adjacent to the respective scoop grooves ( 24 . 30 ) Slings ( 25 . 34 ) are arranged, which the promotion of the fluid in the Schöpfrillen ( 24 . 30 ) support. Differential according to one of claims 3 to 9, characterized in that the bearing point ( 17 . 16 ) is designed so that this one shaft shaft wheel as Achsrad ( 9a , b) absorbs. Differential according to one of claims 1 to 10, characterized in that the second part ( 10 ) is a steel component, in particular a forged steel component, is. Differential according to one of claims 1 to 11, characterized in that the first part ( 11 ) is a cast component. Differential according to one of claims 1 to 12, characterized in that it is a two-part housing ( 7 ), the four differential gears ( 8a -D), which by means of a bolt crosspiece ( 17 ) are locked.

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