DE102017117954A1 - Planet carrier for a planetary gear - Google Patents

Abstract

The invention relates to a method for producing a planet carrier (1) for a planetary gear, comprising the steps of: - stamping the planet carrier (1) from a thin - walled sheet (15), wherein in the sheet (15) punched - out openings (8) for receiving the Planetary gears (4) and holes (9, 10) for receiving pins (5) for mounting the planet gears (4) are introduced, - bending of the planet carrier (1), wherein the holes (9, 10) are aligned with each other and each spaced by 90 ° from the Ausstanzöffnung (8) are arranged, whereby a U-shaped profile (19) arises.- cutting the planet carrier (1) along its length (L), wherein the planet carrier (1) of a strip material (16) bending the planet carrier (1) into a circular shape; and welding the respective ends (17, 18) of the planet carrier (1) to form a circular planet carrier (1). The invention further relates to a planet carrier (1), which is produced by such a method.

Description

The invention relates to a planet carrier for a planetary gear and a method for producing a planet carrier for a planetary gear according to the preamble of the independent claims.

Planetary gears are used in a variety of applications to translate the speed and torque of an input shaft to a speed different from the speed of the input shaft and a correspondingly adjusted torque. In the automotive industry, for example, planetary gear are known to translate the speed of an electric starter and to be able to drive the crankshaft of the engine with a corresponding torque at a starting process of the internal combustion engine. In addition, planetary gear in many other applications, especially in the consumer goods industry in use.

From the prior art, different planet carrier for differential gear or transfer case are known, the components are made by machining and / or formed from a cast material. Other planet carriers include components which are produced by an extrusion molding process or are formed without cutting from a sheet metal material.

The DE 10 2011 006 285 A1 discloses a planetary gear whose planet carrier is composed of two substantially identical carrier cheeks. The Planetenradbolzen are fitted via stepped end zones positively into corresponding receptacles of the support cheeks. By means of the guided through the planetary gear bolts, the carrier cheeks are fastened together, forming a kind of housing cage.

From the EP 2 615 335 A1 is a preferably made of a sheet metal planet carrier of a planetary gear known. The planet carrier forms a housing, the support cheeks have star-shaped projections, which are intended to receive the Planetenradbolzen and planetary gears.

According to the document DE 43 02 844 C1 The planet carrier comprises a hub component and an opposite side wall component, which receive a plurality of planet gear bolts in corresponding bores. Coincidentally, both components of the planet carrier are formed as extruded components or as sheet metal press components, which are welded together to form a structural unit.

The DE 601 09 978 T2 shows a planetary carrier comprising a one-piece or housing constructed housing, which includes both the support cheeks and the connecting webs.

The DE 10 2011 003 706 A1 shows a planet carrier made of sheet metal, which includes two largely designed as a disk body carrier cheeks, which are connected via connecting webs as a spacer element. In this case, all components made of sheet metal of the planet carrier are positively and materially connected to each other. A disadvantage of the known solutions, however, is that they are relatively heavy and / or relatively expensive or have a low flexural rigidity.

The object of the invention is to produce a particularly lightweight, rigid and cost-effective planet carrier and to overcome the disadvantages known from the prior art.

• - Stanzen des Planetenträgers aus einem dünnwandigen Blech, wobei in das Blech Ausstanzöffnungen zur Aufnahme der Planetenräder und Löcher zur Aufnahme von Pins zur Lagerung der Planetenräder eingebracht werden,
• - Biegen des Planetenträgers, wobei die Löcher fluchtend zueinander ausgerichtet werden und jeweils um 90° beabstandet von der Ausstanzöffnung angeordnet werden, wobei ein U-förmiges Profil entsteht,
• - Schneiden des Planetenträgers auf eine Länge, wobei der Planetenträger von einem Bandmaterial des Blechs getrennt wird,
• - Biegen des Planetenträgers in eine Kreisform, und
• - Verbinden der jeweiligen Enden des Planetenträgers, sodass ein kreisförmiger Planetenträger entsteht.

According to the invention the object is achieved by a method for producing a planetary carrier for a planetary gear, which comprises the following steps:

• - Punching the planet carrier from a thin-walled sheet metal, wherein in the sheet punching holes are introduced for receiving the planetary gears and holes for receiving pins for supporting the planet gears,
• Bending the planetary carrier, wherein the holes are aligned with each other and are arranged at 90 ° from the punching opening, whereby a U-shaped profile is formed,
• Cutting the planet carrier to a length whereby the planet carrier is separated from a strip material of the sheet,
• - Bending the planet carrier in a circular shape, and
• - Connecting the respective ends of the planet carrier, so that a circular planet carrier arises.

A thin-walled sheet in this context means a sheet having a maximum material thickness of 3 mm, preferably of not more than 2 mm, in particular of not more than 1.2 mm. Such a planet carrier for applications in the consumer goods industry can therefore be easily and inexpensively produced as a stamped and bent part, wherein the Ausstanzöffnung and the holes are punched out of the starting material and the strip material is rolled into a U-shaped profile. Subsequently, the U-shaped profile is bent circular in a further bending process and thereby the two cut ends circumferentially connected to each other. Preferably, the two Cut ends welded together, creating a circular planet carrier without protrusions and a rework of the planet carrier is not necessary. However, the bending of the U-shaped profile on the "high edge" in the circular rounding of the profile requires high forming forces and high machine and tooling effort. The method for producing the planet carrier and the planet carrier are therefore suitable only for light loads and are not suitable, for example, for use in motor vehicle transmissions. Furthermore, bending over the "high edge" when circular bending for larger sheet thicknesses can lead to deformation of the legs of the U-profile. This requires additional effort, such as a downstream smoothing process, which precludes the task of producing the most cost-effective planetary carrier.

The features listed in the dependent claims advantageous improvements and developments of the specified in the independent claim method for producing a planet carrier for a planetary gear are possible.

In a preferred embodiment of the invention it is provided that prior to bending of the planet carrier in the circular shape slots are introduced into the legs of the U-shaped profile to reduce the flexural rigidity of the sheet and thus to facilitate the bending of the U-shaped profile to the circular planet carrier , As a result, deformation, in particular corrugation, can be avoided when circularly bending the U-shaped profile, which simplifies the manufacture of the planet carrier and reduces the machine and tool expenditure in circular circular bending. However, such slots lead to a weakening of the planet carrier, whereby the load capacity of the planetary gear is further reduced.

According to the invention, a planetary carrier is proposed for a planetary gear, wherein the planet carrier is produced by means of a method according to the invention. An inventive planet carrier can be produced particularly inexpensively and is therefore particularly suitable for use in price-sensitive products of the consumer goods industry, in which only small mechanical loads are transmitted by the planetary gear.

In a preferred embodiment of the invention, it is provided that a sheet thickness of the thin-walled sheet is a maximum of 3 mm, preferably a maximum of 2 mm, particularly preferably a maximum of 1.2 mm. A thin-walled sheet metal allows a simpler bending process to be realized, so that the process forces occurring remain low and can therefore be controlled with less machine and tool expenditure. This applies both to the first bending process, in which a U-shaped profile is bent from the strip material, as well as in circular circular bending of the planet carrier.

The various embodiments of the invention mentioned in this application are, unless otherwise stated in the individual case, advantageously combinable with each other.

• 1 ein Verfahren zur Herstellung eines erfindungsgemäßen Planetenträgers, wobei aufeinanderfolgend die einzelnen Fertigungsschritte dargestellt sind;
• 2 ein Planetenrad eines Planetengetriebes mit einem erfindungsgemäßen Planetenträger in einer Schnittdarstellung; und
• 3 einen erfindungsgemäßen Planetenträger in einer Schnittdarstellung und in einer dreidimensionalen Darstellung.

The invention will be explained in more detail with reference to a preferred embodiment and the accompanying drawings. Show it:

• 1 a method for producing a planet carrier according to the invention, wherein successively the individual manufacturing steps are shown;
• 2 a planetary gear of a planetary gear with a planet carrier according to the invention in a sectional view; and
• 3 a planet carrier according to the invention in a sectional view and in a three-dimensional representation.

In 1 is a method for producing a planet carrier according to the invention 1 shown. This is the planet carrier 1 manufactured as a stamped and bent part. In a first production step I becomes the thin-walled sheet metal 15 from a band material 16 , in particular an aluminum, copper or steel material, processed by means of a stamping process and a Ausstanzöffnung 8th for a planetary gear 4 , as well as in the tape direction of the strip material 16 each right and left of the punched hole 8th a hole 9 . 10 punched out. In this case, according to the number of planets of the planetary gear several Ausstanzöffnungen 8th and holes 9 . 10 in the thin-walled sheet metal 15 brought in. In a process step connected or downstream of the stamping process, the strip material is formed in a forming process 16 a U-shaped profile 19 with a first leg 20 and a second leg 21 bent, with the holes 9 and 10 in each case at right angles to the Ausstanzöffnung 8th and aligned with each other so that a pin 5 through the holes 9 . 10 can be inserted, thereby creating rounded bending edges 12 which the respective legs 20 . 21 with the exit area 22 connect.

In a second production step II becomes the U-shaped profile 19 to a length L cut off, which the unwound length of the circular planet carrier 1 equivalent. In this case, the U-shaped profile 19 after cutting, a first end 17 and a second end 18 on. In a third production step III , which is preferably carried out in multiple stages, is the U-shaped profile 19 bent into a circular shape, with a bending radius 13 downsized with the process steps of the bending process until the first end 17 and the second end 18 can be brought to cover.

In a fourth production step IV become the first end 17 and the second end 18 welded together, making a circular planet carrier 1 arises. This creates a weld 7 passing along a complete cutting plane through the U-shaped profile 19 runs. After the welding process are the respective holes 9 . 10 a thigh 20 . 21 on a common bolt circle 11 which is the central axis of the planetary carrier 1 worn planet gears 4 equivalent.

In 2 is a section through a planetary gear of a planetary gear with a planet carrier according to the invention 1 shown. This will be the planetary gears 4 each by a pin 5 worn and are by means of needle bearings 2 rotatable on the pin 5 stored. In the axial direction are between the planetary gears 4 and the planet carrier 1 shims 3 arranged to limit the radial play and the planet gears 4 to position exactly. On the pins 5 can lubricant channels 6 be trained to lubricate the needle roller bearings 2 to enable. The planet carrier 1 has a central opening 14 on, through which an unillustrated drive or output shaft of the planetary gear with the planetary gears 4 can come into operative connection.

In 3 is the planet carrier according to the invention 1 shown as a single item in a sectional view and in a three-dimensional representation. It can be seen in the sectional view that the planet carrier 1 from a bent U-shaped profile 19 exists, whose both ends 17 . 18 by means of a weld 7 connected to each other. The two thighs 20 . 21 of the U-shaped profile 19 have a distance B ₁ to each other, which is the width of the male planetary gears 4 and possibly additional shims 3 equivalent. The U-shaped profile has a width B ₂ on which of the width B ₁ as well as the double material thickness of the sheet 15 equivalent. There are between the thighs 20 . 21 and the exit area 22 one bending radius each _Rx educated. The holes 9 . 10 are aligned with each other and have a diameter D ₃ as well as a distance R ₃ from a central axis of the planet carrier 1 on. The central opening 14 has a diameter D ₂ on and the circular planet carrier 1 a diameter D ₁ ,

In summary, it can be stated that it is by an inventive method for producing a planet carrier 1 is possible, a particularly lightweight, rigid and cost-effective planet carrier 1 manufacture and thus reduce the cost and weight for a planetary gear.

LIST OF REFERENCE NUMBERS

1

planet carrier

2

needle roller bearings

3

Focusing

4

planet

5

Pin code

6

lubricant channel

7

Weld

8th

Ausstanzöffnung

9

first hole

10

second hole

11

PCD

12

bending edge

13

bending radius

14

central opening

15

sheet

16

band material

17

first end

18

second end

19

U-shaped profile

20

first leg

21

second leg

22

output surface

B ₁

Wide planet

B ₂

Wide planet carrier

D ₁

Diameter of the planet carrier

D ₂

Diameter of the central opening

D ₃

Diameter of the holes

L

Length of the planet carrier

R ₃

Distance of the bolt circle from the central axis

_Rx

bending radius

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 102011006285 A1 [0004]
• EP 2615335 A1 [0005]
• DE 4302844 C1 [0006]
• DE 60109978 T2 [0007]
• DE 102011003706 A1 [0008]

Claims (4)

Method for producing a planetary carrier (1) for a planetary gear, comprising the following steps: - Punching of the planet carrier (1) from a thin-walled metal sheet (15), wherein in the plate (15) Ausstanzöffnungen (8) for receiving the planet gears (4) and holes (9, 10) for receiving pins (5) for supporting the Planet gears (4) are introduced, - Bending of the planet carrier (1), wherein the holes (9, 10) are aligned with each other and each arranged at 90 ° spaced from the Ausstanzöffnung (8), wherein a U-shaped profile (19) is formed. - Cutting the planet carrier (1) to its length (L), wherein the planet carrier (1) from a strip material (16) of the sheet (15) is separated, - Bending the planet carrier (1) in a circular shape, and - Welding of the respective ends (17, 18) of the planet carrier (1), so that a circular planet carrier (1) is formed. Method according to Claim 1 , characterized in that prior to bending of the planetary carrier (1) slots in the legs (20, 21) of the U-shaped profile (19) are introduced to reduce the flexural rigidity of the sheet (15) and thus bending the U-shaped To facilitate profile (19) to the circular planet carrier (1). Planet carrier (1) for a planetary gear, wherein the planet carrier (1) with a method according to one of Claims 1 or 2 is made. Planet carrier (1) to Claim 3 , characterized in that a sheet thickness of the thin-walled sheet (15) is at most 3mm.

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