DE102017111039A1 - Multi-part gear with shaft-hub connection - Google Patents

Abstract

The invention relates to a gearwheel (1) with two toothing components connected in a rotationally fixed manner to one another via a positive shaft-hub connection (2), wherein a first toothed component (3) forms a shaft section (5) of the shaft-hub connection (2) and a second toothing component (4) forms a hub portion (6) of the shaft-hub connection (2), wherein the shaft portion (5) and / or the hub portion (6) has a polygonal surface contour (7, 8), wherein the at least a surface contour (7, 8) of a plurality, in the circumferential direction directly merging into each other flattenings (9) is formed. In addition, the invention relates to a planetary gear with several gears used as planets (1).

Description

The invention relates to a (multi-part) gear for a planetary gear, with two mutually connected via a positive shaft-hub connection rotatably connected gear components, wherein a first gear component forms a shaft portion of the shaft-hub connection and a second gear component a hub portion of the shaft hub Connection forms. Furthermore, the invention relates to a planetary gear with this gear.

Generic multi-part gears for planetary gear are already known from the prior art. In this context, the DE 10 2012 202 446 A1 a gear wheel, in particular a sun gear, for a differential gear.

Further prior art is known from DE 10 2009 052 791 A1 known.

From the state of the art gearwheels in multi-part design are thus already known whose different gear components are on the one hand relatively difficult to machine in the assembly process and on the other hand often difficult to maintain the desired relative position to each other.

It is therefore the object of the present invention to remedy the known from the prior art disadvantages and in particular to provide a multi-part gear available, which is significantly reduced in terms of manufacturing effort and allows a constant relative position with respect to its individual gear components.

This is inventively achieved in that the shaft portion and / or the hub portion have / have a polygonal surface contour, wherein the at least one surface contour of a plurality, in the circumferential direction directly merging into each other flattenings is formed.

As a result, the positive shaft-hub connection / rotary connection can be implemented relatively inexpensively. Elaborate, previously common gear profiles, such as notched / serrations are avoided.

Further advantageous embodiments are claimed with the subclaims and explained in more detail below.

In particular, it is preferable to form at least the shaft section with this polygonal surface contour (first surface contour). As a result, the production of the first toothing component is significantly facilitated because it is not to be provided with two different teeth.

It is also advantageous if the flattenings / each two adjacent flats merge into one another in the circumferential direction without gaps / without any gaps. Thus, it is further excluded that under the polygonal surface contour in particular no gearing, such as a mating or spline is meant. Rather, the contour of the surface thus means a contour which is free of recesses / notches / toothed feet extending inwardly in the radial direction (tendency).

The first surface contour / the shaft section thus preferably forms an imaginary, circumferential rim, which is hollow and has only an extension in the tangential direction / circumferential direction and in the axial direction. As a result, a surface contour is given, which is particularly easy to produce without cutting.

In addition, it is advantageous if the flattenings are formed as flat surface areas.

In a further preferred embodiment, it is implemented that the first polygonal surface contour (forming an outer contour) of the shaft portion is complementary to a second polygonal surface contour (forming an inner contour) of the hub portion and positively receives in the direction of rotation the second surface contour. Thus, a particularly powerful positive connection is implemented.

If the first toothing component is secured axially relative to the second toothing component by means of a securing ring, a securing element produced at low cost is used. In this context, it is particularly advantageous if the retaining ring is engaged in an annular groove of the hub portion penetrating end portion of the shaft portion. On an axial side facing away from the securing ring, the hub portion is then preferably supported axially directly on an end face of a toothed section of the first toothing component, which toothing section adjoins the shaft section axially.

As an alternative to a positive axial locking by means of the locking ring, however, it is also possible in principle to connect / secure the two toothed components in a material-locking or force-locking manner. In the case of a material connection, a joint connecting the two tooth components is preferred. In the case of a material connection is a the two compound components connecting pressing compound preferred, wherein the shaft portion is pressed into the hub portion / additionally held by a press fit.

If the two gear components are externally toothed and / or formed with different gear diameters (i.e., gear is stepped), the result is a gear which is particularly suitable for use as a planetary gear.

In this regard, it is further expedient if the two gear components each have a helical toothing. As a result, the gear is used particularly effectively, since it brings with it a required axial support of the gear components.

In this context, it is again expedient if the helical toothings of the different toothing components differ with respect to their inclination / toothing angle.

More preferably, however, the helical gears are the same aligned / oriented.

Furthermore, it is advantageous if the first surface contour of the shaft section and / or the second surface contour of the hub section is hardened.

The manufacturing cost of the gear is further reduced in particular when the first toothing component (in the region of its shaft portion) forming the first surface contour forming, preferably cold or hot forming, particularly preferably processed extrusion technology. In principle, such machining is also conceivable for forming the second surface contour on the second toothed component (in the region of the hub portion), according to a further embodiment. However, the second toothed component is more preferably designed as a sintered part or forged part / produced by sintering technology. Also, the first toothing component can in principle be designed as a sintered part or forging.

The invention further relates to a gearwheel with two toothed components which are non-rotatably connected to one another via a positive shaft-hub connection, wherein a first toothing component forms a shaft section of the shaft-hub connection and a second toothed component forms a hub section which is positively connected to the shaft section in one direction of rotation Shaft-hub connection forms, wherein a surface contour of the shaft portion and / or the hub portion is not machined / not machined / machined / formed. In particular, this also applies to the above-described first and second surface contours of the shaft and hub sections. Thus, the manufacturing cost of the gear is significantly reduced.

In addition, the invention relates to a planetary gear with a plurality of planet gears according to the invention used according to at least one of the embodiments described above, wherein the first gear components part of a first planetary stage and the second gear components are part of a second planetary stage. As a result, the gears are used particularly efficiently.

In other words, according to the invention, a shaft-hub connection for a two-part stepped planet is realized. A polygon connection is used to connect two gears (gear components). The axial securing is ensured by a locking ring. Thus, the two gears are connected via a positive shaft-hub connection. At least one form-fitting element (shaft section and / or hub section) preferably has a non-machined surface / surface contour. This is further preferably produced by cold or hot forming, in particular extrusion. Alternatively, sintering to form the surface is possible. The teeth are further preferably the same orientation, but have a different flank / tilt angle.

The invention will now be explained in more detail below with reference to figures in a preferred embodiment.

• 1 eine Längsschnittdarstellung eines erfindungsgemäßen als Planetenrad ausgebildeten Zahnrades nach einem bevorzugten Ausführungsbeispiel, wobei besonders gut die axiale Sicherung zweier Verzahnungsbestandteile des Zahnrades über einen Sicherungsring erkennbar ist,
• 2 eine Seitendarstellung des Zahnrades nach 2 in einem ungeschnittenen Zustand,
• 3 eine Querschnittdarstellung des Zahnrades nach den 1 und 2 entlang der in 1 mit „III-III“ gekennzeichneten Schnittlinie, wobei insbesondere eine Polygonform verschiedener Oberflächenkonturen eines Wellenabschnittes eines ersten Verzahnungsbestandteiles sowie eines Nabenabschnittes eines zweiten Verzahnungsbestandteiles erkennbar sind,
• 4 eine perspektivische Explosionsdarstellung des Zahnrades nach den 1 bis 3,
• 5 eine perspektivische Darstellung des zusammengebauten Zahnrades nach den 1 bis 3 von einer Seite eines Sicherungsringes, der zur axialen Sicherung der beiden Verzahnungsbestandteile zueinander vorgesehen ist, sowie
• 6 eine perspektivische Darstellung des in 3 bereits geschnitten dargestellten Zahnradabschnittes.

Show it:

• 1 a longitudinal sectional view of a gear formed according to the invention as a planet gear according to a preferred embodiment, with particularly good the axial securing of two gear components of the gear via a locking ring can be seen,
• 2 a side view of the gear after 2 in an uncut condition,
• 3 a cross-sectional view of the gear after the 1 and 2 along the in 1 with "III-III" marked cutting line, wherein in particular a polygonal shape of different surface contours of a shaft portion of a first toothing component and a hub portion of a second toothing component are visible,
• 4 an exploded perspective view of the gear according to the 1 to 3 .
• 5 a perspective view of the assembled gear after the 1 to 3 from one side of a retaining ring, which is provided for axially securing the two gear components to each other, as well as
• 6 a perspective view of the in 3 already shown cut gear section.

The figures are merely schematic in nature and are for the sole purpose of understanding the invention. The same elements are provided with the same reference numerals.

In 1 is a gear according to the invention 1 according to a preferred embodiment in its basic structure clearly visible. The gear 1 is as a multi-piece gear 1 executed. The gear 1 thus has two partial gears / gear parts, hereinafter referred to as gear components 3 and 4 are designated. Thus, the gear forms 1 a gear unit / gear arrangement. The two gear components 3 and 4 of the gear 1 are by means of a positive shaft-hub connection 2 rotatably connected. The two gear components 3 and 4 are therefore connected via a positive connection in the direction of rotation / rotationally fixed.

The gear 1 is used in operation in a planetary gear not shown here for clarity sake. The planetary gear is further preferably used in turn in an electric drive axle (E-axis). The drive axle, in addition to the planetary gear on an electric motor, which is rotatably coupled on the part of its rotor with a component of the planetary gear (preferably with a planet carrier or a sun gear). The gear 1 is actually designed as a planetary gear of the planetary gear. In the planetary gear are several of these gears 1 arranged distributed in the circumferential direction in the form of planet gears. Through the two gearing components 3 and 4 forms the gear 1 two planetary part wheels (first planetary part by first gear component 3 and second planetary part by second gear component 4 ) of different planetary stages. The first gear component 3 of the respective gear 1 is in this planetary gear part of a first planetary stage, whereas the second gearing component 4 Part of a second planetary stage is.

As further in 1 is recognizable is on the first gearing component 3 a wave section 5 educated. This wave section 5 forms the shaft of the shaft-hub connection 2 out. A hub of the shaft-hub connection 2 is through a hub section 6 on the second gear component 4 educated. shaft section 5 and hub section 6 are in the assembled state after 1 pushed into one another so that they engage in rotation with each other and thus a non-rotatable positive connection between the two gear components 3 and 4 form.

How very good in 3 and in synopsis of 4 to 6 recognizable, both the shaft section 5 as well as the hub section 6 each a polygonal surface contour 7 . 8th on. The first surface contour 7 at the shaft section 5 in the form of an outer contour is complementary to a second surface contour 8th at the hub portion 6 formed in the form of an inner contour. The two surface contours 7 . 8th are matched to each other in terms of their diameter / size that they are inserted into each other, and are supported in the circumferential direction / direction of rotation form-fitting together. Every surface contour 7 . 8th ( 3 ) has several flats 9 on. The individual flattenings 9 the first surface contour 7 each lie on a flattening 9 the second surface contour 8th at.

The flattenings 9 are formed by flattened surface areas. The flattenings 9 immediately merge into one another along the circumference / in the circumferential direction. The flattenings 9 thus seamlessly / seamlessly merge into each other. Under a flattening 9 is to be understood here in particular a flat surface, as in 3 is apparent. In principle, it is under a flattening 9 however, to understand any surface area that is also curved, but viewed in cross-section has a larger radius than an imaginary one extending through the circumferential ends of the surface area concentric with a central axis 13 of the gear 1 extending circular line is formed. Thus, both form the first surface contour 7 as well as the second surface contour 8th each viewed in cross section a polygonal / polygonal, here a dodecagon, from whose sides always connect with a positive angle to each other.

In 4 is the shaft section 5 recognizable in sole consideration. The shaft section 5 forms a longitudinal portion of the first gear component 3 out, who is untoothed. At this shaft section 5 closes in the axial direction (with respect to the central axis 13 ) a gear section 14 on, which is another longitudinal portion of the first gear component 3 formed. The toothing section 14 forms a first external toothing 15a of the gear 1 out. Of the toothed section 14 is in the assembled state, as in 2 recognizable, to a second external toothing 15b of the gear 1 arranged adjacent in the axial direction. The second external toothing 15b is on a radial outer side of the disc-shaped second toothing component 4 educated. The external gears 15a . 15b have different gearing diameters. The first external toothing 15a has a smaller gearing diameter than the second outer gearing 15b , Both external gears 15a . 15b are as helical gears 11 . 12 of the gear 1 educated. A first helical toothing 11 of the first gear component 3 has another (here a smaller) angle of inclination than a second helical toothing 12 of the second gear component 4 , The gear 1 is therefore holistic as a stepped gear 1 executed. Both helical gears 11 . 12 are aligned the same. In other versions are the external teeth 15a . 15b Alternatively, each formed as a straight toothing.

The shaft section 5 is made in this embodiment via an extrusion molding process / extruded. As a result, the manufacturing cost of the gear is essential 1 reduced. In particular, the extrusion molding process directly produces the first surface contour 7 with trained. The first surface contour 7 is therefore without tension, preferably from a previously circular outer peripheral side of the first gear component 3 trained out. Alternatively, the first surface contour 7 can also be produced by conventional milling / grinding.

In this embodiment, the second gear component is 4 designed as a sintered part and thus the second surface contour 8th produced by sintering. The second surface contour 8th / the hub section 6 on the second gear component 4 However, in principle, according to further embodiments, also be configured by means of such extrusion molding process. Thus, the second surface contour is also 8th made without tension. Alternatively, the second surface contour 8th can also be produced by conventional milling / grinding.

The surface contours 7 . 8th form thus formally non-cutting, ie non-cutting, trained surfaces (first surface contour 7 as radial outer surface, second surface contour 8th as a radial inner surface). The shape of the surface contours 7 . 8th is therefore formed without cutting. The surface contours 7 . 8th However, they are still surface-treated, in particular hardened, whereby the surface texture is changed, but the shape / contour is retained.

In 5 it can be seen that a circlip 10 for axially securing the two gear components 3 and 4 serves each other. The circlip 10 is at a the Verzahnungsabschnitt 14 opposite end region 16 of the shaft section 5 anchored. The circlip 10 is in an annular groove 17 in the shaft section 5 positively locked. The circlip 10 is executed as a snap ring. The circlip 10 therefore supports the hub portion 6 / the second gearing component 4 to a first axial side relative to the shaft portion 5 / the first gear component 3 from. As further in 1 is apparent, the hub portion 6 / the second gear component 4 to a, the first axial side facing away, the second axial side via a radial shoulder 18 relative to the shaft section 5 / the first gear component 3 supported. This paragraph 18 is directly through an axial end face of the toothed section 14 with trained. Therefore, the two gearing components 3 and 4 releasably connected again. The shaft-hub connection 2 is therefore also implemented as a form-fitting and again detachable connection.

For the sake of completeness, it should be pointed out that the previously described production methods are merely exemplary. The shaft section 5 as well as the hub section 6 are each in principle by means of any forming technology, such as cold or hot forming technical manufacturing process can be formed. Also, the shaft and hub sections 5 . 6 in principle also be formed by means of a sintering process, in which case preferably the respective toothing component 3 . 4 is formed in this sintering process.

In other words, according to the invention, a two-part planet (gear 1 ) are positively connected by a polygon connection to transmit torque through this connection during operation. Axial becomes the planet 1 optionally by a locking ring 10 or secured by welding. When joining the mold compound 2 can also be considered a press association. Then the hub would have to be before joining 6 heated, pressed and cooled.

LIST OF REFERENCE NUMBERS

1

gear

2

Shaft-hub-connection

3

first gear component

4

second gearing component

5

shaft section

6

hub portion

7

first surface contour

8th

second surface contour

9

flattening

10

circlip

11

first helical toothing

12

second helical toothing

13

central axis

14

toothed section

15a

first external toothing

15b

second external toothing

16

end

17

ring groove

18

paragraph

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012202446 A1 [0002]
• DE 102009052791 A1 [0003]

Claims (10)

Gear (1) with two interlocking with each other via a positive shaft-hub connection (2) gear components, wherein a first gear component (3) a shaft portion (5) of the shaft-hub connection (2) and a second toothing component (4 ) forms a hub portion (6) of the shaft-hub connection (2), characterized in that the shaft portion (5) and / or the hub portion (6) has a polygonal surface contour (7, 8), wherein the at least one Surface contour (7, 8) of a plurality, in the circumferential direction directly merging into flats (9) is formed. Gear (1) to Claim 1 , characterized in that the flattenings (9) merge seamlessly in the circumferential direction. Gear (1) to Claim 1 or 2 , characterized in that the flattenings (9) are formed as flat surface areas. Gear (1) after one of Claims 1 to 3 , characterized in that a first surface contour (7) of the shaft portion (5) is complementary to a second surface contour (8) of the hub portion (6) and positively engages the second surface contour (8) in the direction of rotation. Gear (1) after one of Claims 1 to 4 , characterized in that the first toothing component (3) by means of a retaining ring (10) relative to the second toothing component (4) is axially secured. Gear (1) after one of Claims 1 to 5 , characterized in that the two gear components (3, 4) are externally toothed and / or formed with different toothing diameters. Gear (1) after one of Claims 1 to 6 , characterized in that the two gear components (3, 4) each have a helical toothing (11, 12). Gear (1) after one of Claims 1 to 7 , characterized in that the first toothing component (3) is machined by forming the first surface contour (7). Gear (1) with two mutually via a positive shaft-hub connection (2) rotatably connected gear components (3, 4), wherein a first gear component (3) forms a shaft portion (5) of the shaft-hub connection (2) and a second toothing component (4) forms a hub section (6) of the shaft-hub connection (2) that is positively connected with the shaft section (5) in one direction of rotation, characterized in that a surface contour (7, 8) of the shaft section (5) and / or the hub portion (6) is not machined. Planetary gear with several gears used as planets (1) according to one of Claims 1 to 9 wherein the first gear components (3) are part of a first planetary stage and the second gear components (4) are part of a second planetary stage.

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