DE102018108541B4 - Drive train section, in particular for a gear arrangement for an electrically drivable axle of a vehicle, as well as the electrically drivable axle - Google Patents

Abstract

Drive train section (9), with a plurality of multi-stage planets (1), with a planet carrier (16), wherein the planets (1) are rotatably arranged on the planet carrier (16), and with a first and a second drive shaft (11, 12 ), with a first and a second sun gear (14,15) and with a differential device (17), wherein the first sun gear (14) with a planet section (PA1) of the respective planet (1) and the second sun gear (15) with a another planet section (PA3) of the respective planet (1) meshes, characterized in that the respective planet (1) has at least one first planet section (PA1), the first sun gear (14) meshing with the first planet section (PA1), - that the respective planet (1) furthermore has a second planetary section (PA2), the second planetary section (PA2) forming an input into the differential device (17), - that the first planetary section (PA1) and the second planetary section (P A2) are designed together as a first component (5), - that the planet (1) has a third planet section (PA3), which as a second component (6) rotatably on the first component (5) between the first and the second Planet section (PA1, PA2) is arranged, wherein the second sun gear (15) meshes with the third planet section (PA3).

Description

Field of invention

The invention relates to a drive train section with a plurality of multi-stage planets, with a planet carrier, wherein the planets are rotatably arranged on the planet carrier, and with a first and a second drive shaft, with a first and a second sun gear and with a differential device, the first Sun gear meshes with a planet section of the respective planet and the second sun gear meshes with a further planet section of the respective planet, for a gear arrangement of an electrically drivable and an electrically drivable axle.

A triple planetary shaft is known from the prior art, which consists of three planets. These three planets are rotatably connected to each other. Each planet is first manufactured individually and then welded together.

So revealed, for example DE 1 227 749 A a stationary planetary gear in which each of the planets forms a triple planetary shaft in such a way that this triple planetary shaft has three planetary sections. The first two planetary sections are formed from a common tooth system, which is interrupted by a toothed section. The third planetary section sits on this toothed section, which is formed separately from the toothed section but is mounted on it and non-detachably attached. The third planetary section is in mesh with a sun gear. Each of the other two toothed sections is in meshing engagement with a ring gear.

A turbine starter gear with double stepped planets is US US 2013/0 91 863 A1 disclosed. The stepped planet is formed from a first planet section and a second planet section. The first planetary section has a planetary gear with a small diameter and a hub. The second planetary section sits on the hub and is larger in diameter. The first and second planetary sections are secured to one another by a welded joint.

A driveline portion of a driven axle is in U.S. 5,533,943 A described. The drive train section is formed from a planetary gear and a bevel gear differential. The planetary gear has a set of double step planets, a sun gear and a ring gear. The planet carrier of the planetary gear is formed at least on one side by a housing of the bevel gear differential. The sun gear is the drive gear and drives a planet section with a large diameter of the respective stepped planet. The respective stepped planet is supported on the ring gear via a planetary section of the stepped planet with a small diameter. The step planets are each mounted on a planet bolt. The respective planet pin sits in the planet carrier or in the housing of the bevel gear differential.

Arrangements comparable to the arrangement mentioned above are shown with U.S. 5,807,205 A and DE 10 2011 079 975 A1 for electrically driven axles disclosed. However, these differ from the aforementioned arrangement with a bevel gear differential in that they have a spur gear differential.

In DE 10 2015 225 171 A1 discloses an electric drive train section for a vehicle having a plurality of double planets. Furthermore, the drive train section has a planet carrier, the planets being arranged on the planet carrier. The axes of rotation of the planets are located in a pitch circle around a main axis of the drive train section. The drive train section has a first and a second drive shaft. A first sun gear is arranged on the first drive shaft and a second sun gear is fixedly arranged on the second drive shaft. The first sun gear meshes with the first planet section, the second sun gear meshes with the third planet section.

In addition, the drive train section has a differential device which is operatively connected to the planet carrier by a further planetary stage.

Summary of the invention

The invention is therefore based on the object of creating a drive train section which is particularly robust.

The object is achieved by the features of claim 1. Further advantageous configurations emerge from the respective subclaims, the description and the drawings.

• dass der jeweilige Planet mindestens einen ersten Planetenabschnitt aufweist, wobei das erste Sonnenrad mit dem ersten Planetenabschnitt kämmt,
• dass der jeweilige Planet weiterhin einen zweiten Planetenabschnitt aufweist, wobei der zweite Planetenabschnitt einen Eingang in die Differentialeinrichtung bildet,
• dass der erste Planetenabschnitt sowie der zweite Planetenabschnitt gemeinsam als ein erstes Bauteil ausgebildet sind,
• dass der Planet einen dritten Planetenabschnitt aufweist, welcher als ein zweites Bauteil drehfest auf dem ersten Bauteil zwischen dem ersten und dem zweiten Planetenabschnitt angeordnet ist, wobei das zweite Sonnenrad mit dem dritten Planetenabschnitt kämmt,

According to the invention, the following is provided for a drive train section:

• that the respective planet has at least one first planet section, wherein the first sun gear meshes with the first planet section,
• that the respective planet furthermore has a second planet section, the second planet section forming an input into the differential device,
• that the first planet section and the second planet section are designed together as a first component,
• that the planet has a third planet section, which is arranged as a second component non-rotatably on the first component between the first and the second planet section, the second sun gear meshing with the third planet section,

The three-stage or multi-stage planet has at least or exactly three planetary segments. Each of the planetary sections has a spur gear area, the spur gear areas each having a circumferential toothing. The toothing can be designed, for example, as a straight toothing or a helical toothing. The planetary sections and / or the spur gear areas are preferably spaced apart from one another in the axial direction.

At least or exactly two of the planetary sections, that is to say a first and a second planetary section, are designed as a first component. In particular, the first and the second planetary section are produced together with the first component by primary molding. As an alternative or in addition, the first and second planetary sections are made from a common semi-finished product. The first and the second planetary section thus consist of a common material area.

The third planet section is designed as a second component which, prior to the method for producing the planet, is designed separately from the first component. In the manufacturing method, the second component is applied to the first component in a rotationally fixed manner. The connection between the first component and the second component can be implemented in a form-fitting, non-positive and / or cohesive manner.

In the context of the invention, it is proposed that the third planetary section be arranged between the first and the second planetary section with respect to an axial extension of the planet. The second component and thus the third planetary section is thus positioned between the first and the second planetary section.

It is a consideration of the invention that so far the planet sections have been arranged individually on the base body. This leads to increased assembly costs due to the large number of parts and to increased production costs due to the large number of joints. The method according to the invention also ensures that the resulting planet is designed to be more stable, since the first component already has the first and second planetary sections in one piece. Furthermore, tolerance problems are reduced since no tolerances are introduced by the first and second planetary sections during a wing process.

In a preferred embodiment, the planet has a through opening which is suitable for receiving a bolt, so that the planet is rotatably arranged on the bolt. When integrating the planet into a drive train section, as will be described later, or in an electrical axis, as will be described later, it is preferred that one or more bearing devices, in particular roller bearing devices, are arranged between the bolt and the planet. The through opening is preferably designed as a straight hollow cylinder opening which is particularly easy to manufacture.

In a preferred embodiment, the first and second planetary sections form corner areas and / or edge areas in the first component and / or in the resulting planet. As a result of the planetary sections in the corner and / or edge areas, these are designed to be particularly stable, so that they are more load-bearing and / or more load-bearing. The planet is particularly preferably designed as a triple planet. It is possible that exactly one planetary segment, that is to say the third planetary segment, is inserted as a second component between the first and the second planetary segment. Alternatively, it is possible that several planetary sections are inserted between the first and the second planetary section, the further planetary sections each forming a further separate component in addition to the third planetary section. It is also possible that the second component is equipped with two planetary sections.

In a particularly stable embodiment of the invention, the first component is designed as a forged component, which is subsequently and in particular before the assembly of the second component is machined, in particular finished, in a separating manner.

A free inner diameter of the second component is greater than an outer diameter of the first and / or second planetary section. This enables the second component to be pushed onto the first component. In the case of further developments of the invention it can also be provided that the inner contour of the second component and the outer contour of the first component are designed in such a way that the inner diameter of the outer diameter principally overlap, but can nevertheless be pivoted into one another. For example, it is conceivable that each of the components has a corresponding toothing so that the second component with the internal toothing can be pushed over the external toothing of the first component. Both The teeth can be straight or helical teeth.

In a preferred embodiment of the invention, the second component is set rotatably on the first component by welding. Since the planet usually no longer has to be divided after dismantling, a very stable planet can be produced by such a material connection.

In an alternative embodiment of the invention, the first component has an external toothing and the second component has an internal toothing, which intermesh in such a way that a rotationally fixed connection is formed in the circumferential direction as a radial securing around a main axis of the planet. Any securing elements can be used for axial securing; a securing ring is particularly preferably used for axial securing, since this can be implemented particularly cost-effectively. On another side of the second component, the axial securing can be implemented, for example, by a shaft shoulder.

From a structural point of view, the first planetary section has a first outer diameter, the second planetary section has a second outer diameter and the third planetary section has a third outer diameter, the first outer diameter being greater than the second outer diameter and the inner diameter of the second component being greater than or equal to the second outer diameter. Generally speaking, the inner diameter of the second component is designed such that it can be pushed over the outer diameter of the second planetary section.

The drive train section is in particular an electric drive train section or a hybrid drive train section for a vehicle. The drive train section has a first and a second drive shaft, a first sun gear being arranged on the first drive shaft and a second sun gear being fixedly arranged on the second drive shaft. The first sun gear meshes with the first planet section, the second sun gear meshes with the third planet section. In addition, the drive train section has a plan of a differential device, the second planetary section forming an input into the differential device. Optionally in addition, the drive train section comprises an electric motor, the electric motor being selectively switchable to the first or the second drive shaft. For example, a clutch device and / or a gearbox is arranged between the electric motor and the first or second drive shaft. In this refinement, the drive train section can be designed to be particularly robust, since the planets are particularly stable due to the special production method. The functional reliability of the drive train section is thus increased.

In a preferred development of the invention, the differential device is designed as a planetary differential device. In particular, the differential device has a ring gear, the second planet section meshing with the ring gear. The ring gear is preferably designed as a stationary ring gear. Furthermore, the differential device has two planetary sets and two output sun gears. The planet gears of the two planetary sets are rotatably arranged on the planet carrier. On the one hand, a planetary gear of one planetary set meshes with a planetary gear of the other planetary set. The planet gears of the two planetary sets thus mesh with one another in pairs. Furthermore, the planet gears of one planetary gear set mesh with the first output sun gear and the planet gears of the other planetary gear set mesh with the second output sun gear. Optionally, the output wheels are each connected to an output shaft in a rotationally fixed manner.

Another object of the invention forms an electrically drivable axle for a vehicle, the electrically drivable axle having the drive train section, as has been described above.

Figure list

• 1 eine Längsschnittdarstellung einer aus internen Stand der Technik der Anmelderin bekannten Tripelplanetenwelle;
• 2 eine Längsschnittdarstellung eines Planeten eines Antriebsstrangabschnitts als ein erstes Ausführungsbeispiel der Erfindung;
• 3 eine Längsschnittdarstellung eines Planeten als ein zweites Ausführungsbeispiel der Erfindung;
• 4 eine schematische Darstellung eines Antriebsstrangabschnitts von einem Fahrzeug, ausgebildet als elektrisch antreibbare Achse, als ein weiteres Ausführungsbeispiel der Erfindung.

Further features, advantages and effects of the invention emerge from the following description of preferred exemplary embodiments of the invention. Show:

• 1 a longitudinal sectional view of a triple planetary shaft known from the applicant's internal prior art;
• 2 a longitudinal sectional view of a planet of a drive train section as a first embodiment of the invention;
• 3 a longitudinal sectional view of a planet as a second embodiment of the invention;
• 4th a schematic representation of a drive train section of a vehicle, designed as an electrically drivable axle, as a further embodiment of the invention.

1 shows a triple planetary wave known from the prior art, which consists of three planets. The production takes place in such a way that initially each planet is produced individually. Single planet P3 forms a kind of platform for the other two single planets P2 and P1. First, single planet P1 is welded to single planet P3. Then single planet P2 is also welded to single planet P3. The welding points are indicated by circles.

2 shows the solution according to the invention in a first variant. The two outer planetary sections PA1 and PA2 are not manufactured as two individual parts but as a first component 5 . The toothing of the two planetary sections PA1 and PA2 is being machined. The middle planetary section PA3 is then used as the second component 6th from the side, here from the right, attached to the individual part with a press fit. The subsequent fastening is carried out in this variant by welding at the point marked by a circle.

For this method it is necessary that the inner diameter of the central planet section PA3 is larger than the tip diameter of the planet section PA2. By reducing the individual parts of the triple planetary shaft (from three planets P1, P2, P3 to two components 5 , 6th with tarpaulin sections PA1, PA2, PA3), the production of this overall component is significantly cheaper and assembly is easier.

If you look closer, the 2 a planet 1 , which is designed as a three-stage planet and / or triple planetary shaft. The planet 1 has the three planetary sections PA1, PA2 and PA3, which each form a spur gear section. The planetary sections PA1, PA2 and PA3 each have helical teeth and are arranged at a distance from one another. The planet points in the center 1 a through opening 2 on, in which a bolt 3 is arranged. There are also several storage facilities 4th provided, the storage facilities 4th the planet 1 relative to the bolt 3 to store. In the bolt 3 are bores for supplying lubricant to the bearing equipment 4th intended. The bolt 3 serves to arrange the planet 1 for example on a planet carrier 16 as will be described later.

The planet 1 has a first component 5 and a second component 6th on. The first component 5 includes the first and second planetary sections PA1 and PA2. In particular, the planetary sections PA1 and PA2 are designed in one piece, produced jointly by primary molding or produced separately from the same semi-finished product. For example, the first component is 5 realized as a forged part, the toothing of the planetary sections PA1 and PA2 being reworked to separate. The planetary sections PA 1 and PA 2 are each at the end and / or in the edge area of the first component 5 arranged.

The second component 6th has the third planet section PA3, the second component 6th and / or the third planetary section PA3 in the axial direction between the first planetary section PA 1 and the second planet section PA 2 is arranged.

The first component 5 points at the joint with the second component 6th a cylindrical surface on the outer circumference, the second component 6th points at the joint with the first component 5 a cylindrical surface, the diameters being matched to one another in such a way that the first component 5 sits in a press fit on the second component. The first component 5 has a wave shoulder 7th for the installation of the second component 6th on. The two components 5, 6 are connected to one another via a welding process on one of the shaft shoulders 7th remote side of the second component 6th .

For a design suitable for production, the free inner diameter of the second component is ID3 6th larger than the outer diameter AD2 of the second planet section PA2. in a process for making the planet 1 first the two components 5 , 6th manufactured, followed by the second component 6th over the first component 5 starting at the second planetary section PA2 and pushed with the shaft shoulder 7th brought into plant. The following are the components 5 , 6th welded together. The advantage of the structural design lies in the reduced number of components and the more robust design of the planet 1 .

3 shows the solution according to the invention in a second variant. For this, too, the two outer planetary sections PA1 and PA2 are not manufactured as two individual parts, but as the common component 5 . The toothing of the two planetary sections PA1 and PA2 is being machined. The middle planetary section PA3 is then used as the second component 6th from the side, here from the right, pushed open. The subsequent attachment is carried out in this variant by a radial securing by means of a spline and by an axial securing by means of a locking ring 25th . Otherwise the planets are 1 the 2 and the 3 designed identically, so that reference is made to the previous description.

For this method it is necessary that the tip diameter of the spline of the central planetary section PA3 or of the second component 6th is larger than the tip diameter of the second planetary section PA2.

The 4th shows a vehicle 8th in the area of a drive train section 9 , which as an electrically drivable axle 10 is trained. The electrically driven axle 10 can for example be implemented as a rear axle. Alternatively, this is designed as a front axle.

The powertrain section 9 has a first and a second drive shaft 11 , 12th on which selectively with an electric motor only shown schematically 13th are connectable. For example, a coupling device (not shown) is interposed. On the first drive shaft 11 is a first sun gear 14th , on the second drive shaft 12th is a second sun gear 15th non-rotatably attached. The drive shafts 11 , 12th and the sun gears 14th , 15th are coaxial with a main axis H arranged. The drive shafts 11 , 12th are designed as hollow shafts and arranged concentrically to one another.

The powertrain section 9 has a majority of the previously described planets 1 on. The planets 1 are in a pitch circle diameter around the main axis H arranged distributed. The planets 1 are from a planet carrier 16 carried on which they are rotatably arranged. The drive shafts 11 , 12th comb with the planet 1 , where the first sun gear 14th with the first planet section PA1 and the second sun gear 15th meshes with the third planetary section PA3.

The powertrain section 9 points into the differential device 17th on, with the planet carrier 16 part of the differential device 17th forms. The second planetary section PA2 forms an input to the differential device 17th . The powertrain section 9 and / or the differential device 17th has a ring gear 18th on, the second planet section PA2 meshing with the ring gear. This configuration results in a rotation of the drive shafts 11 or 12th to a rotation of the planet carrier 16 around the main axis H .

Furthermore, the drive train section 9 and / or the differential device 17th two planetary sets 19th , 20th on as well as output sun gears 21 , 22nd on, with the planet gears of the planetary sets 19th , 20th on the planet carrier 16 are rotatably arranged. The planet gears 16 mesh with each other in pairs, so that each one planet gear of the first planetary gear set 19th with a planetary gear of the second planetary set 20th combs. The planet gears of the first planetary set 19th mesh with the first output sun gear 21 , the planet gears of the second planetary set 20th mesh with the second output sun gear 22nd . Without a compensating movement, the planetary sets are 19th , 20th in the block from the planet carrier 16 in the direction of rotation around the main axis H taken away. In the event that compensatory movements between the output sun gears 21 , 22nd are necessary, the compensatory movements are made by rolling the planet gears of the planetary sets 19th , 20th implemented. The first output sun gear 21 is non-rotatably with a first output shaft 23 , the second output sun gear 21 is non-rotatably with a second output shaft 24 connected.

The first output wave 23 runs coaxially to the drive shafts 11 , 12th to a driven wheel of the vehicle 8th , the second output shaft runs to another driven wheel of the vehicle 8th the same axis.

List of reference symbols

1

planet

2

Through opening

3

bolt

4th

Storage facility

5

first component

6th

second component

7th

Shaft shoulder

8th

vehicle

9

Powertrain section

10

electrically driven axle

11

first drive shaft

12th

second drive shaft

13th

Electric motor

14th

first sun gear

15th

second sun gear

16

Planet carrier

17th

Differential device

18th

Ring gear

19th

first planetary set

20th

second planetary set

21

first output sun gear

22nd

second output sun gear

23

first output shaft

24

second output shaft

25th

Circlip

H

Main axis

Claims (5)

Drive train section (9) with a plurality of multi-stage planets (1), with a planet carrier (16), the planets (1) being rotatably arranged on the planet carrier (16), and with a first and a second drive shaft (11, 12 ), with a first and a second sun gear (14,15) and with a differential device (17), wherein the first sun gear (14) with a Planet section (PA1) of the respective planet (1) and the second sun gear (15) meshes with a further planet section (PA3) of the respective planet (1), characterized in that the respective planet (1) has at least one first planet section (PA1) the first sun gear (14) meshing with the first planetary section (PA1), - that the respective planet (1) furthermore has a second planetary section (PA2), the second planetary section (PA2) having an input into the differential device (17) forms, - that the first planetary section (PA1) and the second planetary section (PA2) are designed together as a first component (5), - that the planet (1) has a third planetary section (PA3), which is used as a second component (6 ) is arranged non-rotatably on the first component (5) between the first and the second planetary section (PA1, PA2), the second sun gear (15) meshing with the third planetary section (PA3). Powertrain section after Claim 1 , characterized in that the first sun gear (14) is non-rotatably arranged on the first drive shaft (11) and that the second sun gear (15) is non-rotatably arranged on the second drive shaft (12). Powertrain section after Claim 1 or 2 , characterized in that the first planet section (PA1) has a first outside diameter, that the second planet section (PA2) has a second outside diameter, wherein the first outside diameter is larger than the second outside diameter and wherein the inside diameter of the second component (6) is larger or is equal to the second outer diameter. Drive train section (9) after Claim 1 , 2 or 3 , characterized in that the differential device (17) has a ring gear (18), two planetary sets (19,20) and two output sun gears (21,22), the second planetary sections (PA2) meshing with the ring gear (18), the Planet gears of the two planetary sets (19, 20) are rotatably arranged on the planet carrier (16), the planet gears of the two planetary sets (19, 20) meshing with one another in pairs and the planet gears of one planetary set (19) with one of the output sun gears (21) mesh and mesh the planet gears of the other planetary set (20) with the other of the output sun gears (22). Electrically drivable axle (10) for a vehicle (8), characterized by a drive train section (9) according to one of the Claims 1 , 2 , 3 or 4th .

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