DE102014218737A1 - Two-stage planetary gearbox for reduction of high speeds - Google Patents

Abstract

The invention relates to a two-stage planetary gear for the reduction of high speeds, which has at least the following components:
a first gear stage, comprising:
- At least a first central gear for introducing a torque;
- A plurality of second planetary arranged gear wheels, which are drivable by means of the first gear; and
a second gear stage, comprising:
- A plurality of third planetary arranged gears, which are rotatably connected to the second gear wheels; and
A fourth gear which is drivable by means of the third gear wheels,
wherein in each case a speed reduction takes place from the at least one first gear wheel to the second gear wheels and from the third gear wheels to the fourth gear wheel.
With the two-stage planetary gear proposed here, the use of a high-speed electric motor with a large speed reduction in a small space is possible.

Description

The invention relates to a two-stage planetary gear for the reduction of high speeds, in particular for the direct drive of a motor vehicle wheel, which comprises the driving electric motor and the reduction gear.

From the prior art electrically powered motor vehicles are known in which an electric motor is provided in at least part of the motor vehicle wheels, which drives the respective wheel. The disadvantage here is that the usable electric motors are very large and / or very difficult. In addition, the gears used are highly loaded and also have a lot of space. However, there are also known electric motors, which are smaller and can deliver sufficient power. However, such electric motors have the characteristic that they operate in a very high speed range, for example, to over 20,000 rpm (revolutions per minute). For such speeds, no transmission are known, which can achieve a suitable reduction in a small space.

On this basis, the present invention has the object, at least partially overcome the known from the prior art disadvantages. The object is solved by the features of the independent claims. Advantageous developments are the subject of the dependent claims.

• – zumindest ein erstes zentrales Getrieberad zur Einleitung eines Drehmoments;
• – eine Mehrzahl von zweiten planetenartig angeordneten Getrieberädern, welche mittels des ersten Getrieberads antreibbar sind; und eine zweite Getriebestufe, aufweisend:
• – eine Mehrzahl von dritten planetenartig angeordneten Getrieberädern, welche mit den zweiten Getrieberädern drehfest verbunden sind; und
• – ein viertes Getrieberad, welches mittels der dritten Getrieberäder antreibbar ist,

wobei von dem zumindest einen ersten Getrieberad auf die zweiten Getrieberäder und von den dritten Getrieberädern auf das vierte Getrieberad jeweils eine Drehzahluntersetzung stattfindet. The invention relates to a two-stage planetary gear for the reduction of high speeds, which has at least the following components:
a first gear stage, comprising:

• - At least a first central gear for introducing a torque;
• - A plurality of second planetary arranged gear wheels, which are drivable by means of the first gear; and a second gear stage, comprising:
• - A plurality of third planetary arranged gears, which are rotatably connected to the second gear wheels; and
• A fourth gear which is drivable by means of the third gear wheels,

wherein in each case a speed reduction takes place from the at least one first gear wheel to the second gear wheels and from the third gear wheels to the fourth gear wheel.

The proposed here two-stage planetary gear is composed of a first gear stage and a second gear stage, which are interconnected via the second gears and the third gears. On the at least one first central gear torque is introduced, the torque is still low and the speed very high, for example, more than 10,000 rev / min or even more than 20,000 rev / min. The first at least one central gear is drivingly connected to a plurality of second symmetrically arranged gears, the second gears already rotating more slowly than the at least one first gear.

The plurality of second gears is or all second gears are fixedly connected to a corresponding number of third gears, so that the rotational speed of the third gear wheels is identical to the rotational speed of the second gears. The third gears now drive a fourth gear, with the fourth gear again slower than the third gears.

With the two-stage planetary gear proposed here, a high speed reduction is possible, at the same time the space required, especially axially, is low and allow the loads on the individual wheels a long life of the two-stage planetary gear. With such a two-stage planetary gear a reduction of more than 35 is possible, preferably 35 to 45.

Thus, an electric motor of small size and high power can be used, which operates in a high speed range, but has a low torque. In addition, the gear proposed here is very small and at the same time capable of putting the high speeds in a suitable lower speed and to translate the low torque into a suitable higher torque. Thus, the total application in a wheel of a motor vehicle is possible, the weight and the size are small.

Furthermore, the central first gear is provided as a sun gear and the second gears and the third gears are arranged like planetary gears. A sun gear is centrally located and the planetary gears surround the sun gear. The second and third gears are three, four or more planetary gears which are (evenly) distributed around the sun gear and thus engage the circumference as possible in the sun gear. With the majority of planetary gears, the increase in torque can be mitigated in its effect on the gears.

Furthermore, the second gears and the third gears are suspended on fixed shafts and rotate alone about their respective shaft. In this embodiment, the walk Gear wheels not with respect to the first gear, but their respective axis of rotation, that is, the respective shaft is spatially fixed. This allows easy suspension of the axles of the second and third gears. In addition, a (fixed) abutment for a high torque can be easily formed over several axes.

According to a further advantageous embodiment of the two-stage planetary gear, the fourth gear is formed as a ring gear.

The formation of the fourth gear as a ring gear has several great advantages. First, the increased torque can be distributed by the large speed reduction on a large wheel or a large peripheral surface. Furthermore, interleaving of the gear stages may take place, that is, the axes of the second gears and the third gears may be rearward with respect to the arrangement of the drive unit to the first gear, because the ring gear and the third gears can leave so much space in the center that there a drive, in particular a high-speed electric motor can be arranged. Furthermore, the ring gear with its large diameter forms a non-rotatable, but otherwise elastic coupling to a wheel, optionally as a switchable coupling.

According to a further advantageous embodiment of the two-stage planetary gear, the first gear stage and / or the second gear stage on an arrow toothing, wherein preferably the arrow toothing is formed by a plurality of composite helical gear wheels.

The use of an arrow toothing prevents excessive axial forces acting on the bearing, as is the case with a pure helical toothing, because the resulting axial forces cancel each other during the helical toothing. As a result, an axially soft, acoustically better insulating bearing can be used, that is inexpensive and / or low-loss storage types and that is, in particular bearings that have a smaller size.

Most preferably, the arrow teeth are formed by a plurality of individual helical gear wheels, which are easier and cheaper to manufacture. The sub-wheels can be joined together, for example, by means of positioning features such as, for example, axial embossings, small deviations occurring. These small deviations can be corrected by the gearing itself by an axial displacement takes place. An axial displacement is possible due to a soft axial bearing, which in turn is possible due to the low axial load due to the helical gearing. With this production, a low-cost as well as quiet two-stage planetary gear is achieved.

According to a further advantageous embodiment of the two-stage planetary gear, the first stage bearing of the second gears is at least partially axially within the axial extent of the second gears, and preferably the second stage bearing of the third gears seen from the second gears axially behind the third gears.

Due to the axial overlap between the second gears and the Erststufenlagerung the two-stage planetary gear can be made very short. This has the additional advantage that the bending load on the shaft of the second and third gears is particularly low and also a torque-induced tilting of the second gears is avoided or at least very low fails.

In a preferred embodiment, the second gears are formed as a toothed ring, which is connected on one side via a connection in the form of a metal sheet, or in the form of spokes, with the shaft or is connected via an integrally formed with the shaft connection. This connection to the shaft forms the outer end of the shaft and the bearing connects directly. Depending on the necessary width of the bearing of a respective shaft, the axial extent of the bearing is smaller or larger than the axial extent of the respective second gear.

Most preferably, the second-stage bearing is arranged at the opposite end of the respective shaft, whereby the forces on the bearing greatly reduce or even cancel. In addition, the large planetary gears can be made of different materials, which are set up for example for the toothing or for the torque transmission of the connecting element to the shaft.

According to a further advantageous embodiment of the two-stage planetary gear, the two-stage planetary gear has a one-piece gear carrier component, wherein the gear carrier component has a plurality of first stage receptacles for the first stage storage and a plurality of second stage receptacles for the second stage storage, and partially fulfills housing functions.

By using a one-piece gear carrier component a particularly space-saving and rigid construction is possible, and the assembly of the two-stage planetary gear is particularly easy. The first-stage recordings preferably protrude into the second gearwheels, so that the first-stage bearing can be accommodated.

According to a further advantageous embodiment of the two-stage planetary gear, the two-stage planetary gear has a gear carrier component, wherein the gear carrier component has a plurality of bolts, via which the gear carrier component for attaching a torque can be fastened, wherein the bolts preferably engage between the second gear wheels.

By using a variety of bolts can be produced in a small space sufficient abutment for an applied torque. Most preferably, these bolts engage between the second gears, which is possible only because the second gears and third gears are fixed. Thus, it is not necessary to design the housing or additional corresponding elements such that it engages around the two-stage planetary gear to form a counter bearing for the torque generated. Particularly preferably, the bolts are designed as threaded bolts, which at least over a part of their length have a thread for a screw connection with an attachment element, for example with a suspension element.

According to a further advantageous embodiment of the two-stage planetary gear within the two-stage planetary gear, an electric motor, preferably within a transmission carrier component of the planetary gear, can be arranged and connected to the at least one first gear wheel.

• – eine Felge zur Übertragung eines Drehmoments in eine lineare Bewegung;
• – ein zweistufiges Planetengetriebe nach der obigen Beschreibung mit einem Getriebeträgerbauteil;
• – einen Elektromotor zum Antreiben der Felge,

wobei bevorzugt der Elektromotor innerhalb des Getriebeträgerbauteils angeordnet ist und die Felge auf dem Getriebeträgerbauteil gelagert ist. The proposed arrangement of the two-stage planetary gear allows a particularly small structure in which the electric motor partially protrudes into the two-stage planetary gear and thus axial space is obtained. Most preferably, the electric motor is within a then acting as a housing gear carrier component of the planetary gear, so that the torque is transmitted directly and without further aids to the two-stage planetary gear. In addition, the torque of the electric motor is preferably counteracted via the transmission carrier component, that is, the advantageous outer stator of the electric motor is in rotationally fixed contact with the transmission carrier component. This arrangement also simultaneously enables optimal heat dissipation from the electric motor through the gear carrier component. According to a further aspect of the invention, a motor vehicle wheel is proposed which has at least the following components:

• A rim for transmitting a torque in a linear movement;
• - A two-stage planetary gear as described above with a gear carrier component;
• An electric motor for driving the rim,

wherein preferably the electric motor is arranged within the transmission carrier component and the rim is mounted on the transmission carrier component.

The motor vehicle wheel is intended to drive a motor vehicle and has for this purpose a rim. The rim is adapted to transmit a torque to the outer circumference of the vehicle wheel, for example to the road by means of a tire. Arranged inside the rim is a two-stage planetary gear as described above, which converts a high speed into a suitable drive speed, so that no further reduction or gear ratio between the rim and the planetary gear has to be provided. Furthermore, an electric motor is provided, which drives the rim via the two-stage planetary gear. Particularly preferably, the electric motor is located within the transmission support member and the rim is mounted on the transmission support member. In this case, the transmission support member forms a kind of wheel axle, which forms the counter bearing for torque transmission to the rim. Overall, the vehicle wheel can be identical in its external dimensions with known motor vehicle wheels, so that the implementation in known vehicle dimensions, especially in cars and small vehicles, is possible. In this case, an efficient electric motor can be provided, which can be operated at high speeds and therefore can be built particularly small.

The features listed individually in the claims can be combined with one another in any technologically meaningful manner and can be supplemented by explanatory facts from the description and details from the figures, wherein further embodiments of the invention are shown.

The invention and the technical environment will be explained in more detail with reference to FIGS. The figures show particularly preferred embodiments, to which the invention is not limited. In particular, it should be noted that the figures and in particular the illustrated proportions are only schematic. Show it:

1 a two-stage planetary gear,

2 a two-stage planetary gear with gear carrier component,

3 a two-stage planetary gear with electric motor,

4 : a section of a helical planetary gear,

5 FIG. 3 is a sectional view of a helical planetary gear, FIG.

6 a section of a two-part arrow-toothed planetary gear with axial positioning elements,

7 FIG. 3: a sectional view of a two-part planetary gear with axial positioning elements, FIG.

8th : a motor vehicle wheel with electric motor and two-stage planetary gear.

9 : a motor vehicle wheel with electric motor and two-stage planetary gear and mirrored chassis connection

1 shows a two-stage planetary gear 1 which is a first gear wheel 4 and three second gears 5 . 6 . 7 includes, which is the first gear stage 2 form. The third gears 8th . 9 . 10 are with the second gears 5 . 6 . 7 each firmly over a first wave 12 , second wave 13 or third wave 14 connected. These waves 12 . 13 . 14 are by means of a first first-stage camp 21 , a second first-degree camp 22 and a third first-degree camp 23 in the first gear stage 2 stored and by means of a first two-stage warehouse 24 , a second second-stage camp 25 and a third second-stage camp 26 in the second gear stage 3 stored. The first-degree camps 21 . 22 . 23 are located within the axial extent of the second gears 5 . 6 . 7 , The second-stage bearings 24 . 25 . 26 are located on the second gears 5 . 6 . 7 seen behind the third gears 8th . 9 . 10 ,

In this embodiment, both in the first gear stage 2 as well as in the second gear stage 3 a first arrow toothing 15 or a second arrow toothing 16 intended. For example, the first second gear 5 is the arrow toothing 15 by a first helical part wheel 17 and a second helical gear part 18 formed and also, for example, in the fourth gear 11 is the arrow toothing 16 by a third helical part wheel 19 and a fourth helical gear part 20 educated.

In 2 is a two-stage planetary gear 1 like in the 1 shown, wherein here also a transmission carrier component 27 is provided. This transmission carrier component 27 points for each of the bearings 21 to 26 a recording 28 to 31 on, here the rear (second) images and the rear (second) bearings are hidden in this representation. The first first stage recording 28 is to record the first first-stage camp 21 furnished and the first second stage recording 30 is to receive the first second-stage camp 24 set up. Likewise, the third Erststufenaufnahme 29 for the admission of the third first-stage camp 23 set up and the third second stage recording 31 to accommodate the third second-stage camp 26 set up. Furthermore, the transmission carrier component 27 a first bolt 32 and a third bolt 33 in which a second bolt is concealed in this illustration, with all three bolts 32 . 33 with a screw thread for attachment of the overall structure to, for example, a suspension element (not shown) may be executed.

In 3 is a two-stage planetary gear 1 shown how it is in 2 is shown, in which case in a housing-like recess of the transmission support member 27 an electric motor 34 is provided. Viewed from the gear wheels behind the electric motor 34 is a wheel bearing 37 for a rim 36 intended. The wheel bearing 37 is on the gear carrier component 27 stored. In this illustration, the assembled assignment is the first-time storage 21 . 22 . 23 to the first stage recordings 28 . 29 and the second storage 24 . 25 . 26 to the second stage shots 30 . 31 clear. For example, the first second gear 5 is about a first wave 12 with the first third gear 8th connected, the first wave 12 about the first first-degree camp 21 and the first second-stage camp 24 is stored. The first first-degree camp 21 is in the first first stage recording 28 and the first second-stage camp 24 is in the first second stage recording 30 ,

In 4 is a section of a helical gear, here for example a section of the first helical gear part 17 shown. In 5 is a sectional view of the partial wheel 17 as in 4 shown.

In 6 and 7 are a section or a sectional view of a first helical part wheel 17 and a second helical gear part 18 shown. Especially easy can be by attaching positioning elements 40 of two, preferably identical, partial wheels 17 and 18 when joining an arrow-toothed gear, here for example a first second gear 5 be created, wherein the tooth engagement points due to the axial positioning 40 acoustically advantageous alternately done. The two, preferably identical, partial wheels 17 and 18 For example, by riveting, they can be fixed on a wheel (not shown) as a common carrier. By such a structure of several parts further acoustically advantageous properties are achieved, for example, arise as a damping acting assembly joints.

In 8th is a motor vehicle wheel 35 shown in which a similar arrangement of the two-stage planetary gear 1 is shown as in 3 , The embodiment here differs from that in the 3 especially the fact that the wheel bearing 37 for the rim 36 on the gear carrier component 27 is arranged in a region which coincides with the axial extent of the electric motor 34 covered. This results in a particularly short construction of the motor vehicle wheel 35 achieved and it can be used as a wheelbase as in conventional centrally driven vehicles. The illustrated two-stage planetary gear 1 is done with the help of bolts 32 . 33 on the chassis (not shown) on the inside (shown here on the left) of the vehicle wheel 35 attached, and the rim 36 in a known manner from the outside (shown here right) forth outside the wheel bearings 37 for example by wheel bolts (not shown here) attached.

In 9 is a motor vehicle wheel 35 shown in which one opposite 8th mirrored arrangement of the transmission is implemented. The illustrated motor vehicle wheel 35 is also attached to the landing gear (not shown here), but not on the planet side (here different than in 8th shown right) of the two-stage planetary gear 1 (bolts 32 carry here only one housing cover 38 ), but on the opposite wheel bearing side (shown here on the left) with the attachment 39 , The rim 36 is fastened in this case from the wheel inside, before the entire vehicle wheel 35 with the two-stage planetary gear 1 with drive (the electric motor 34 ) is attached to the landing gear (not shown here). This arrangement has the advantage that the wheel load (vehicle weight) on the transmission components of the two-stage planetary gear 1 passed into the landing gear, making the two-stage planetary gear 1 can work undisturbed. The gears 4 to 11 (See, for example 1 ) are now on the outside of the vehicle wheel 35 (here as in 8th shown on the right) and are by a housing-fixed cover 38 that with the gear carrier component 27 connected, encapsulated. This non-rotating lid 38 unlike a rotating hubcap is a distinctive feature of the wheel and can significantly contribute to branding.

With the two-stage planetary gear proposed here, the use of a high-speed electric motor with a large speed reduction in a small space is possible.

LIST OF REFERENCE NUMBERS

1

 Two-stage planetary gear

2

 first gear stage

3

 second gear stage

4

 first gear wheel

5

 first second gear

6

 second second gear

7

 third second gear

8th

 first third gear

9

 second third gear

10

 third third gear

11

 fourth gear

12

 first wave

13

 second wave

14

 third wave

15

 first arrow toothing

16

 second hedge toothing

17

 first helical part wheel

18

 second helical part wheel

19

 third helical part wheel

20

 fourth helical part wheel

21

 first first-degree camp

22

 second first-degree camp

23

 third first-degree camp

24

 first second-stage warehouse

25

 second second-stage warehouse

26

 third second-stage camp

27

 Gear carrier component

28

 first first stage recording

29

 third first stage recording

30

 first second stage recording

31

 third second stage recording

32

 first bolt

33

 third bolt

34

 electric motor

35

 motor vehicle wheel

36

 rim

37

 Wheel bearings

38

 transmission cover

39

 attachment

40

 positioning

Claims (8)

Two-stage planetary gear ( 1 ) for the reduction of high speeds, comprising at least the following components: a first gear stage ( 2 ), comprising: - at least one first central gear ( 4 ) for introducing a torque; A plurality of second planetary gears ( 5 . 6 . 7 ), which by means of the first gear ( 4 ) are drivable; and a second gear stage ( 3 ), comprising: - a plurality of third planetary gears ( 8th . 9 . 10 ), which with the second gear wheels ( 5 . 6 . 7 ) are rotatably connected; and - a fourth gear ( 11 ), which by means of the third gears ( 8th . 9 . 10 ) is drivable, wherein at least one first gear wheel ( 4 ) on the second gears ( 5 . 6 . 7 ) and of the third gears ( 8th . 9 . 10 ) on the fourth gear ( 11 ) in each case a speed reduction takes place. Two-stage planetary gear ( 1 ) according to claim 1, wherein said fourth gear ( 11 ) is designed as a ring gear. Two-stage planetary gear ( 1 ) according to one of the preceding claims, wherein the first gear stage ( 2 ) and / or the second gear stage ( 3 ) an arrow toothing ( 15 . 16 ), wherein preferably the arrow toothing ( 15 . 16 ) by a plurality of composite helical gear wheels ( 17 . 18 . 19 . 20 ) is formed. Two-stage planetary gear ( 1 ) according to one of the preceding claims, wherein the first-stage storage ( 21 . 22 . 23 ) of the second gears ( 5 . 6 . 7 ) at least partially axially within the axial extent of the second gears ( 5 . 6 . 7 ) and prefers the second stage storage ( 24 . 25 . 26 ) of the third gears ( 8th . 9 . 10 ) of the second gears ( 5 . 6 . 7 ) seen axially behind the third gear wheels ( 8th . 9 . 10 ) is located. Two-stage planetary gear ( 1 ) according to one of the preceding claims, wherein the two-stage planetary gear ( 1 ) a transmission carrier component ( 27 ), wherein the gear carrier component ( 27 ) a plurality of first stage recordings ( 28 . 29 ) for first stage storage ( 21 . 22 . 23 ) and a plurality of second stage recordings ( 30 . 31 ) for the second stage storage ( 24 . 25 . 26 ) having. Two-stage planetary gear ( 1 ) according to one of the preceding claims, wherein the two-stage planetary gear ( 1 ) a transmission carrier component ( 27 ), wherein the gear carrier component ( 27 ) a variety of bolts ( 32 . 33 ), wherein the bolts ( 32 . 33 ) between the second gears ( 5 . 6 . 7 ). Two-stage planetary gear ( 1 ) according to one of the preceding claims, wherein within the two-stage planetary gear ( 1 ) an electric motor ( 34 ), preferably within a transmission carrier component ( 27 ) of the planetary gear ( 1 ), and with the at least one first gear ( 4 ) is connectable. Motor vehicle wheel ( 35 ), comprising at least the following components: - a rim ( 36 ) for transmitting a torque in a linear movement; A two-stage planetary gear ( 1 ) according to one of the preceding claims with a transmission carrier component ( 27 ); - an electric motor ( 34 ) for driving the rim ( 36 ), wherein preferably the electric motor ( 34 ) within the transmission carrier component ( 27 ) is arranged and the rim ( 36 ) on the gear carrier component ( 27 ) is stored.

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