DE102007040479A1 - Differential gear with Planetenkegelrad - Google Patents

Abstract

The invention relates to a differential gear (100) having a sum shaft (10) for distributing torques to a first differential element (40) and to a second differential element (42) via at least one Planetenkegelrad (50), wherein the Planetenkegelrad (50) so operatively connected in that the Planetenkegelrad (50) is in meshing engagement with a first toothing (41) on the first differential element (40) and with a second toothing (43) on the second differential element (42), wherein the axis of rotation of the Planetenkegelrades (50) perpendicular to the axis of rotation of the sum shaft (10) and the axis of rotation of each differential element (40, 42) extends, and is characterized in that the sum shaft (10) is formed as a spur gear (20) in which the at least one Planetenkegelrad (50) is mounted ,

Description

Field of the invention

The The invention relates to a differential gear with a sum shaft for the distribution of torques to a first differential element as well as to a second differential element via at least one Planetenkegelrad, wherein the Planetenkegelrad is so operatively connected, that the Planetenkegelrad in meshing engagement with a first toothing on the first differential element and with a second toothing on the second differential element is, wherein the axis of rotation of the Planetenkegelrades perpendicular to the axis of rotation of the sum shaft and the axis of rotation each differential element runs.

Background of the invention

Bevel gear differential gears are well known in the art. An example of such a differential gear shows the document US 2006/0025267 A1 , Although these differential gear can transmit very high torque, but they require a large amount of space and have due to the massive design a high weight, so that they are unsuitable for use especially in small and mid-size cars.

Therefore were in the prior art, primarily in differential gears With planetary construction, attempts made that weight and the To reduce space.

The publication EP 0 918 177 A1 shows a spur gear differential of the prior art. The spur gear differential has a drive wheel which is formed by a ring gear but can also be designed as a spur gear preferably with helical gearing. The drive wheel is rotatable together with a planet carrier about the axis of rotation and attached to the planet carrier. The drive wheel, the housing with planet carrier and the output gears of the spur gear differential together have the axis of rotation. torques are fed into the spur gear differential to the planet carrier via the drive wheel.

Of the Planet carrier or the housing as Planet carrier is the so-called sum wave of the differential. The sum wave is the link, each the largest Torque leads. The output shafts are non-rotatable with the driven wheels coupled and are the so-called difference waves. The difference waves each give a difference amount of the introduced into the differential torques for example, to the driven vehicle wheel on. In the state the technology is the planet carrier or the Housing as planetary carrier the sum shaft 50th of the planetary drive.

in the The prior art are either ring gears or sun gears as output gears equated to the difference waves, since these each rotatably connected to the output shafts or over further transmission elements are coupled to these. The output wheels are therefore also referred to as Designated differential links.

After the publication EP 0 918 177 A1 the differential housing is rotatably connected to the planet carrier. The planetary pins, also referred to as bearing journals, are mounted only once in the middle of their length on the planetary carrier. They stand on both sides of the planet carrier in the differential housing and are rotatably mounted on this. At the projecting portions of the planetary pin planet gears are formed on both sides of the planet carrier fixed or firmly connected to the respective planet pins.

One Another spur gear differential is in a specialist article of the ATZ 01/2006, "Compact axle drive for vehicles with front-wheel drive and transversely mounted engine ", the authors Höhn, Michaelis and Heizungsröther described.

at This differential gear is in each case a planetary gear to the respective Bolt axis rotatably mounted on a portion of the planet pins. The planet pins are in this case rotationally fixed to the planet carrier. The planetary gears with planet pins are each on one annular orbit arranged around the axis of rotation.

The Output gears can have internal gear teeth be, each of which rotatably coupled to an output shaft is. The output shafts are usually each with a driven Vehicle wheel in an operative connection.

each the planetary gear is with another of the planetary gears paired for a mutual meshing. Also comb those with planet wheels one side with a first ring gear and all planet gears on the other side with a second one Ring gear. The torque is transmitted through the planetary gears distributed to the ring gears and thus to the output shafts and passed from there to the driven vehicle wheels.

The Planetary wheels of a pair are in this differential with the longitudinal half the tooth width each with each other engaged. The outer in the longitudinal direction Half the tooth width of each gear of a pair meshes with one of the internally toothed ring gears. The longitudinal direction is the direction in the axis of rotation of the Differentials is directed.

Around is to enable the meshing described above, is the planet carrier made of sheet metal in the area of the respective Planetenradpaarung alternately put through in the longitudinal direction and broken in the radial direction of the planetary gears, so that the planetary wheels of a pairing are roughly longitudinal Comb the middle of the differential with each other.

One Criterion for the assessment of functional accuracy of a planetary drive is the accuracy of the meshing of the combing planet pairing, planetary sun and Planetary ring gear. The accuracy of the meshing in turn is about the usual manufacturing tolerances addition of relocations and deformations that occur during operation the Stirnraddifferentials occur. In the middle and generally also laterally only once recorded planet pins are especially at high loaded differentials susceptible to deflection and, as a result, the planet gears seated on the bolt are susceptible to tipping. The consequences can Inadmissible noises, inaccurate meshing and be premature wear. That's also why differentials come the prior art is preferably used in vehicles, in which relatively low torques are transmitted have to.

Of the Advantage of the spur gear differential of the prior art is in its lightweight construction of sheet metal. The lightweight construction with sheet metal in particular, as described in the technical paper, for the planet carrier makes sense. The settings of the bearings and breakthroughs for the meshing can be simply by pulling or stamping and punching into the sheet contribute.

adversely However, the thin sheet on the initially mentioned Deformation behavior of the planet carrier, in particular because the plate of the planet carrier in addition weakened by the breakthroughs. As a result, It may also be disadvantageous in turn, if the Berührradius is too big. The use of thicker sheet for compensation the deformation susceptibility would be in such a Case the advantages of the lightweight differential at least partially destroy it.

The space available to such differentials on the vehicle is usually low, so that the differentials should have relatively small outer dimensions. The ability to transmit torques, on the other hand, as well as in EP 0 918 177 A1 is described, apart from the criteria tooth width, geometry and others essentially determined by the average Berührradius. The larger the contact radius is, the higher is the amount of transmittable moments, subject to the initially mentioned influence of the deformation susceptibility.

Even if that is in EP 0 918 177 A1 described spur gear whose planetary gears engage in ring gears, due to the external meshing between planet and output and thus in terms of its capacity to transmit torque compared to a dimensionally identical classic cone wheel differential or differential gears with sun wheels as difference in terms is in itself, it is still Aim to make the differentials as light and small as possible and very high load capacity.

As already mentioned, the tooth width is a criterion for the amount of transferable torque. The wider the meshing, the higher the moments that can be transmitted become. Due to wider meshing, need the differentials along, so axial, more space and be thus altogether heavier and more expensive.

In the differential gears described above, the planet gears of a pair mesh with each other. At the same time, each of the planetary gears of one pair is in meshing engagement with a different differential link than the other paired planetary gear. If in this differential one or both planetary gears with two differential links (for example, at the same time with both sun gears) would be engaged, the compensation would be blocked in the differential. In the design of the planetary drive is therefore sufficient free space for the teeth of each of the two differential elements for itself to provide that planetary gear, with the teeth may not be the respective differential element engaged. In the differential according to the document EP 09 918 177 A1 is sufficient axial space between the meshing provided to the respective sun, by the planetary gear is longer by the amount of space required axially. Such an arrangement requires by the axially longer planetary additional axial space. As a result, the entire differential gear is heavier and takes up a large amount of space.

The Bolt axes of the planet pins of a pair are circumferentially behind each other. Like many pairs of planetary gears circumferentially can be arranged depends on the circumferential distance from, given by the dimensions of the planet gears is and is also crucial to the design of the storage locations for the planet wheels and their surrounding construction is dependent.

That in the publication EP 0 918 177 A1 described differential and the associated in the aforementioned technical article practical example, each have three symmetrically distributed on the circumference pairs of planetary gears - but it is in the pamphlet EP 0 918 177 A1 pointed out that at higher torque to be transmitted by the differential more than three pairs can be used. Both the use of more than three pairs and the transmission of high torques is in terms of the available space in the arrangements of both versions of the prior art according to the document EP 0 918 177 A1 difficult. In addition, the previously described by deformation certain load limits of the centrally arranged planet carrier made of sheet metal for the lightweight differentials made of sheet metal. If such differentials are to be designed for higher loads, correspondingly more space is required. The differential becomes heavier and more expensive. Therefore, these types of prior art are preferably used in differentials, with which relatively low torques must be transmitted.

Object of the invention

Of the Invention is therefore based on the object, the advantage of lightweight construction of differential gears with planetary construction with that of the high Moment transmission of bevel gear differential gears too combine and provide a differential that for the cost-effective and space-saving use in small and middle class car is suitable.

Summary of the invention

These Task is by differential gear with a sum shaft for the distribution of torque to a first differential element as well to a second differential element via at least one Planetenkegelrad solved, wherein the Planetenkegelrad is so operatively connected, that the Planetenkegelrad in meshing engagement with a first toothing on the first differential element and with a second toothing the second differential element is, wherein the axis of rotation of the Planetenkegelrades perpendicular to the axis of rotation of the sum shaft and the axis of rotation each differential element extends, and is characterized that the sum shaft is designed as a spur gear in which the at least a Planetenkegelrad is stored.

The proposed solution avoids a separate differential with solid differential carrier or solid support parts. Basically, it is proposed only a massive Provide component. There on the massive spur gear of the sum shaft can not be dispensed with, the spur gear is considered rigid, solid manufactured carrier component used. The tasks of the differential carrier takes over essentially the massive spur gear. Other tasks, like the Storage of the differential links, are to be flipped by two Pulling parts solved cost-effectively and weight-saving. Costly machining technologies become so for avoided the carrier parts. Nevertheless, the differential gear is due to the bearing of the Planetenkegelrades in the massive spur gear able to transmit great moments.

In A preferred embodiment provides that the first differential element in a first carrier part and stored the second differential element in a second carrier part is.

In In a preferred embodiment, the spur gear is axial formed symmetrically.

It can be provided that the spur gear and the first and the second Carrier part in each case a number rotationally symmetrically arranged Through holes, through the fasteners for Connecting the spur gear with the first and the second carrier part are guided.

In According to one embodiment, the first differential element and the second differential element each as Sonnenkegelrad with outside lying toothing trained.

Preferably The spur gear has a double T-shaped cross-section wherein at least one recess is provided in the spur gear, in each case at least one Planetenkegelrad is arranged.

It may further be provided that more than one Planetenkegelrad is provided and the Planetenkegelräder identical to each other are formed.

Preferably the carrier parts are manufactured as drawing stamping parts. The first and the second carrier part can be identical be formed to each other.

In an embodiment, it is provided that the first and the second differential element each for receiving an output shaft are formed by means of a plug connection.

It may further be provided that the first and the second Carrier each have a cup-shaped central Section which is surrounded by a bearing.

According to one Embodiment is provided that the first differential element in the cup-shaped portion of the first support member extends and is stored in this and the second differential element in the cup-shaped portion of the second support member extends and is stored in this.

alternative can be provided that the first differential element is not in the cup-shaped portion of the first support member does not extend and the second differential element in the cup-shaped portion of the second support member, wherein an inner surface each pot-shaped section for guiding a Output shaft is provided.

Further Advantages and embodiments of the invention will become apparent from the Description and attached drawing.

It it is understood that the above and the following yet to be explained features not only in each case specified combination, but also in other combinations or can be used in isolation, without the scope of the present To leave invention.

Brief description of the drawings

The Invention will be described below with reference to embodiments explained in more detail. In the corresponding Drawing shows:

1 different views of a differential gear according to the invention,

2 a cross-sectional view of a differential gear according to the invention in a first embodiment,

3 a cross-sectional view of a differential gear according to the invention in a second embodiment,

4 various embodiments of a spur gear of a differential gear according to the invention,

5 an exploded view of a differential gear according to the invention.

Detailed description the drawings

1 shows various views of a differential gear according to the invention 100 ,

In the proposed differential gear 100 it is a bevel gear differential gear, the principle of operation is known in the art from the prior art and is therefore not described again here.

According to the invention it is provided that a spur gear 20 and a first carrier part 30 and a second carrier part 32 a sum shaft or a differential carrier 10 form.

The spur gear 20 has a helical toothing and provides the drive-side terminal of the differential gear 100 ago. According to the invention, only the spur gear is proposed 20 provided as a solid component to ensure the absorption and distribution of the drive torque. Since a solidly manufactured spur gear can not be dispensed with, according to the invention the spur gear is used as a rigid, massively manufactured carrier component.

The task of the differential carrier or the transmission of the torque is achieved by two identical, to be flanged to the spur gear parts, which are the carrier parts 30 . 32 form. The carrier parts 30 . 32 can thus be produced inexpensively in large quantities.

The carrier parts 30 . 32 themselves are in radial camps 80 . 82 stored and can to their stiffening stiffening ribs 31 exhibit.

The carrier parts 30 . 32 have through holes through which they are connected to the spur gear 20 get connected.

2 shows a side cross-sectional view of a differential gear according to the invention 100 and a first embodiment.

The spur gear 20 is with the support parts 30 . 32 by means of several fasteners 60 connected. For the fasteners 60 it can be bolts or screws. A welding of the elements is not provided, whereby the assembly of the differential gear 100 can be carried out inexpensively. By dispensing with welding bonds is also a heating of the spur gear 20 and the support parts 30 . 32 avoided, whereby the risk of distortion of the components is eliminated.

For the speed compensation between a first differential element 40 and a second differential element 42 is at least one Planetenkegelrad 50 intended.

The difference members 40 . 42 are each connected to an output shaft (not shown). According to the invention, both the first differential element 40 as well as the second differential element 42 an internal toothing, which allows a connection to a corresponding output shaft via a plug connection.

For optimum torque and weight distribution, a rotationally symmetrical design with at least two, better three bevel gears or planetary bevel gears is recommended 50 to get an imbalance in the differential gear 100 to avoid. In the in 5 illustrated embodiment are at For example, three Planetenkegelräder 50 intended.

Dependent However, the space available in each application can additional planetary gears are added. The differential gear according to the invention can with both an even and an odd number Bevel gears are produced inexpensively.

The planetary pinions 50 and the difference limbs 40 . 42 If necessary, radial and / or axial sliding bearings can be obtained. Also, needle rings can be provided for better storage.

The entire differential gear 100 is constructed axially symmetrical, wherein the Planetenkegelräder 50 and the difference limbs 40 . 42 to save space in the spur gear 20 are integrated.

According to the planetary bevel gears 50 directly in the spur gear 20 stored. In the in 2 The first embodiment shown, the differential elements 40 . 42 in a corresponding carrier part 30 . 32 guided. A pot-shaped central section 35 of the first carrier part 30 and a cup-shaped central portion 37 the second carrier part 32 can thus be provided for guiding the respective output shaft (not shown).

3 shows a second embodiment of the differential gear according to the invention 100 ,

In contrast to the first embodiment, it is provided that the difference elements 40 . 42 each in a corresponding cup-shaped section 35 . 37 a corresponding difference element 30 . 32 extend. Thus, the difference terms 40 . 42 additionally in the corresponding pot-shaped section 35 . 37 guided. The internal gears to the connector with a corresponding output shaft (not shown) are formed axially longer accordingly.

4 shows various possible embodiments of a spur gear 20 ,

The 4a to 4d show embodiments that are for receiving one, two, three or four Planetenkegelrädern 50 are provided. It is in a in the spur gear 20 provided recess 22 according to a planetary bolt 53 used, on which a corresponding Planetenkegelrad 50 in turn is rotatably mounted. The planetary pin 53 is accordingly rotationally fixed in the spur gear 20 arranged. As in the 4b to 4d it can be seen, are the recesses 22 arranged rotationally symmetrical.

To reduce the weight of the spur gear 20 can also be provided that more than one Planetenkegelrad 50 per recess 22 is provided. For example, two Planetenkegelräder 50 in a recess 22 be provided, with only a correspondingly long planet pins 53 Use finds.

By storing the planetary pinions 50 right in the massive spur gear 20 a significant space saving is achieved. In addition, the carrier parts 30 . 32 cost-effective and weight-saving are produced as cold-formed sheet metal parts, as the solidly manufactured spur gear 20 solves the essential tasks of guiding and centering of the individual components or torque transmission.

5 shows an overall view of a differential gear according to the invention 100 in a second embodiment.

In this embodiment, there are three planetary pinions 50 provided, each by means of a planetary bolt 53 in a corresponding recess 22 of the spur gear 20 are stored. The difference members 40 . 42 are each designed as sun gears with external toothing, resulting in cup-shaped sections 35 . 37 extend.

The first difference element 40 is about a first toothing 41 with the planetary pinions 50 and the second difference element 42 over a second toothing 43 with the planetary pinions 50 engaged.

The difference members 40 . 42 each have an internal toothing 44 . 45 on, via which they can be connected by means of a plug connection with an output shaft (not shown).

The first carrier part 30 and the second carrier part 32 are by means of several fasteners 60 to the spur gear 20 flanged. The carrier parts 30 . 32 lead or store the difference elements 40 . 42 and close the differential gear 100 ,

The carrier parts 30 . 32 in turn are themselves in radial bearings 80 . 82 stored.

By the differential gear according to the invention is a space-saving differential gear is provided which In addition, inexpensive and easy to manufacture and can be mounted and thus for use in small or middle class cars is suitable.

10

total wave

20

spur gear

22

recess

24

Through Hole

30

first support part

31

stiffening rib

32

second support part

34

Through Hole

35

cup-shaped central section

37

cup-shaped central section

40

first differential element

41

first Perforation

42

second differential element

43

second Perforation

44

internal teeth

45

internal teeth

50

planetary bevel gear

53

planet shaft

60

fastener

80

first camp

82

second camp

100

differential gear

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

• US 2006/0025267 A1 [0002]
• - EP 0918177 A1 [0004, 0007, 0017, 0018, 0022, 0022, 0022]
• EP 09918177 A1 [0020]

Claims (13)

Differential gear ( 100 ) with a sum wave ( 10 ) for the distribution of torques to a first differential element ( 40 ) as well as to a second differential element ( 42 ) via at least one Planetenkegelrad ( 50 ), wherein the Planetenkegelrad ( 50 ) is operatively connected so that the Planetenkegelrad ( 50 ) in tooth engagement with a first toothing ( 41 ) on the first differential element ( 40 ) and with a second toothing ( 43 ) on the second differential element ( 42 ), wherein the axis of rotation of the Planetenkegelrades ( 50 ) perpendicular to the axis of rotation of the sum shaft ( 10 ) and the axis of rotation of each differential element ( 40 . 42 ), characterized in that the sum wave ( 10 ) as a spur gear ( 20 ) is formed, in which the at least one Planetenkegelrad ( 50 ) is stored. Differential gear ( 100 ) according to claim 1, characterized in that the first differential element ( 40 ) in a first carrier part ( 30 ) and the second differential element ( 42 ) in a second carrier part ( 32 ) is stored. Differential gear ( 100 ) according to claim 1 or 2, characterized in that the spur gear ( 20 ) is formed axially symmetrical. Differential gear ( 100 ) according to one of claims 1 to 3, characterized in that the spur gear ( 20 ) and the first ( 30 ) and the second ( 32 ) Carrier part in each case a number of rotationally symmetrically arranged through-holes ( 24 . 34 ), by the fastening elements ( 60 ) 5 for connecting the spur gear ( 20 ) with the first ( 30 ) and the second ( 32 ) Carrier part are guided. Differential gear ( 100 ) according to one of claims 1 to 4, characterized in that the first differential element ( 40 ) and the second differential element ( 42 ) are each formed as Sonnenkegelrad with external toothing. Differential gear ( 100 ) according to one of claims 1 to 5, characterized in that the spur gear ( 20 ) has a double T-shaped cross section, wherein in the spur gear ( 20 ) at least one recess ( 22 ) is provided, in the respective at least one Planetenkegelrad ( 50 ) is arranged. Differential gear ( 100 ) according to one of claims 1 to 6, characterized in that more than one Planetenkegelrad ( 50 ) is provided and the Planetenkegelräder ( 50 ) are formed identical to each other. Differential gear ( 100 ) according to one of claims 1 to 7, characterized in that the carrier parts ( 30 . 32 ) are produced as drawing stamping parts. Differential gear ( 100 ) according to one of claims 1 to 8, characterized in that the first ( 30 ) and the second ( 32 ) Carrier part are formed identical to each other. Differential gear ( 100 ) according to one of claims 1 to 9, characterized in that the first ( 40 ) and the second ( 42 ) Differential element depending Weil are formed to receive an output shaft by means of a plug connection. Differential gear ( 100 ) according to one of claims 1 to 10, characterized in that the first ( 30 ) and the second ( 32 ) Support member each have a cup-shaped central portion ( 35 . 37 ) from a warehouse ( 80 . 82 ) is surrounded. Differential gear ( 100 ) according to claim 11, characterized in that the first differential element ( 40 ) in the cup-shaped section ( 35 ) of the first carrier element ( 30 ) and is mounted in this and the second differential element ( 42 ) in the cup-shaped section ( 37 ) of the second carrier element ( 32 ) and is stored in this. Differential gear ( 100 ) according to claim 11, characterized in that the first differential element (15) 40 ) not in the cup-shaped section ( 35 ) of the first carrier element ( 30 ) and the second differential element ( 42 ) not in the cup-shaped section ( 37 ) of the second carrier element ( 32 ), wherein an inner surface of each cup-shaped portion ( 35 . 37 ) is provided for guiding an output shaft.