PLANETARY DRIVE COMPRISING A PLANET CARRIER

Abstract

A planetary drive includes a planet carrier and planetary gears. The carrier includes two axially-facing carrier plates and at least one connecting element. The connecting element is a linear strip of metal that is bent to take the shape of a cylinder for assembly. The strip of metal connects the two carrier plates while maintaining them in a spaced apart relationship. The strip includes a plurality of openings or holes for receiving a part of the planetary gears as they rotate. The strip is a separate element from the carrier plates, but is assembled to and between the plates.

Claims

1. A planetary drive comprising: a planet carrier and planetary gears, wherein the planet carrier includes two axially opposing carrier elements and at least one connecting element, and wherein the carrier elements are axially connected to one another via the connecting element, and retained at an axial spacing, wherein the planetary gears are supported with a radial spacing about an axially oriented central axis of the planetary drive on the carrier elements, such that the planetary gears protrude radially beyond the connecting element through radial openings of the planet carrier, wherein the connecting element includes at least one cylindrical metal strip that forms a hollow cylinder that runs around the central axis of the planetary drive, the metal strip having two ends facing one another in the direction of the circumference, and wherein the metal strip is connected to both carrier elements, wherein the openings are delimited by the material of the metal strip, at least in the direction of the circumference.

2. The planetary drive according to claim 1, wherein the openings are formed in the metal strip and in that the inner contour of the openings is bordered by the material of the metal strip.

3. The planet carrier for a planetary drive according to claim 1, wherein the carrier elements are carrier plates made of sheet metal, wherein the planet carrier is formed by the carrier plates and the metal strip.

4. The planet carrier according to claim 3, wherein the metal strip sits on the outside of a cylindrical outer contour of the respective carrier plate.

5. The planet carrier according to claim 3, wherein a greatest width of the metal strip aligned with the central axis in the axial direction corresponds to the width of a band material, from which the metal strip is produced, wherein the width is equal to or less than the spacing between the carrier plates.

6. A method for producing a planet carrier according to claim 3, comprising bending the metal strip into a curved, hollow cylindrical shape, wherein the ends of the metal strip face one another, and are attached to one another, and attaching at least one carrier plate to the metal strip.

7. The method according to claim 6, wherein the metal strip is made of a band material present in a flat state, wherein a width of the band material is equal to or less than the spacing of the carrier plates to one another on the planet carrier.

8. The method according to claim 7, wherein the metal strip is cut from the band material at a length that corresponds to the circumference of the completed connecting element.

9. The method according to claim 7, wherein the openings are formed when the metal strip or the band material is in the flat state.

10. The method according to claim 6, wherein the carrier plates are stamped from sheet metal, wherein axial perforations are generated on the carrier plates.

11. The method according to claim 6, wherein the carrier plates are aligned with one another prior to attachment to the metal strip, such that the respective axis of symmetry of at least one perforation in one of the carrier plates is axially aligned with an opposing second perforation in the opposite carrier plate, and connecting bolts are inserted into the carrier plates such that each of the connecting bolts is inserted into a perforation in the one carrier plate and into a further perforation in an opposite carrier plate.

12. (canceled)

13. A planetary carrier assembly, comprising: a pair of planet carrier plates disposed about an central axis and spaced from one another, each planet carrier plate defining an outer radial surface; a plurality of planetary gears supported for rotation about the axis and axially between the planet carrier plates, wherein the planetary gears protrude radially beyond the outer radial surface of the planet carrier plates; and a cylindrical strip disposed about the central axis and axially between the pair of planet carrier plates, the strip defining a plurality of openings that receive at least a portion of the planetary gears, wherein the strip is a separate element attached to the planet carrier plates and has two ends connected to one another and facing one another in a direction of a circumference of the strip.

14. The planetary carrier assembly of claim 13, wherein the strip is not an integral extension of either planet carrier plate.

15. The planetary carrier assembly of claim 13, wherein the strip is assembled to the planet carrier plates.

16. The planetary carrier assembly of claim 13, wherein the planet carrier plates each define a circumferential outer surface, and the strip includes a circumferential inner surface that is attached to the circumferential outer surfaces of the planet carrier plates.

17. The planetary carrier assembly of claim 13, wherein the strip is disposed radially outward of the planet carrier plates.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The invention shall be explained and described below on the basis of an exemplary embodiment of a planetary drive 1.

[0033] FIG. 1 shows a front view of the planetary drive 1;

[0034] FIG. 1a shows a perspective view of the planetary drive 1 depicted in FIG. 1;

[0035] FIG. 2 shows a sectional view of the planetary drive 1 depicted in FIG. 1, cut along line II-II according to FIG. 1;

[0036] FIGS. 3-12 show initial states, or individual parts, of a planet carrier 2 of the planetary drive 1 depicted in FIG. 1, and individual intermediate components of the patent drive produced with the method according to the disclosure; wherein

[0037] FIG. 3 shows an exemplary embodiment of a metal strip 3 in an elongated initial form, prior to the bending;

[0038] FIG. 3a shows a section of an initial material (blank) in the form of a band material 10, from which two metal strips 3 can be produced;

[0039] FIGS. 4-6 show the completed hollow cylindrical curved metal strip 3 from different perspectives; and

[0040] FIGS. 7-9 show plate-shaped carrier elements 4 in a side view and in a front view, respectively,

[0041] FIG. 10 shows an exploded view of the planet carrier 2 depicted in FIG. 11 as a completed intermediate product; and

[0042] FIG. 12 shows an exploded view of the planetary drive 1 depicted in FIG. 1.

DETAILED DESCRIPTION

[0043] The planetary drive 1 depicted in FIGS. 1, 1a, 2 and 12 comprises the planet carrier 2 and planetary gears 5, planet bolts 7, planet bearing 8, and thrust washers 9. The planet drive 1 is formed by the carrier elements 4, such as plates, and the connecting elements 6. The planet bolts 7 sit in one of the carrier elements 4 at the left and right in each case, at a radial spacing to the central axis 11. One of the planetary gears is rotatably supported on each planet bolt 7 by means of a planet bearing 8. The planet bearings 8 are roller bearings and designed in this case as a needle bearing with a cage. Alternatively, the planet carriers can also be sliding bearings, having ball bearings, or bearings of another arbitrary design. A thrust washer 9 is disposed between the planetary gear 5 and the respective carrier element 4. The planet carrier 2 has radial through holes 17. A planetary gear 5 protrudes radially out of each of the radial through holes 17, beyond the outer contour of the planet carrier 2. Moreover, the planetary drive 1 can be stabilized by connecting bolts 20.

[0044] As can be derived from FIGS. 10 and 11, the planet carrier 2 is an intermediate product of a method according to the disclosure, and formed by the two axially opposed carrier elements 4 and the connecting element 6. The carrier elements 4 are axially connected to one another by means of the connecting element 6. The connecting element 6 is a hollow cylindrical, curved metal strip 3 running about the central axis 11 of the planetary drive 1. The metal strip 3 is connected to both carrier elements 4, and sits on a circumferential cylindrical outer contour of the respective carrier element 4. Alternatively, the connecting element 6 can also be disposed axially between the carrier elements 4. The through holes 17 are delimited in the circumferential direction of the planet carrier 2 by cross webs 18 and axially through lateral edges 19 of the metal strip 3 that are curved in the direction of the circumference, about the central axis 11.

[0045] It is visible in FIGS. 7, 8, 9 and 10 that the carrier elements 4 are formed by perforated carrier plates 12 having a circular disk shape. The carrier plates 12 are stamped out of sheet metal, preferably steel sheet metal. The perforations 12 in which the planet bolts 7 are received in the completed planetary drive 1, and perforations 14, which may be provided for further connecting elements or as entries for supplying grease, are formed by stamping thereby.

[0046] The metal strip 3 is a flat strip in the initial state, as is depicted in FIG. 3. The metal strip 3 is preferably cut from a band material 10 depicted in FIG. 3. The width B of the band material corresponds to the axial width B of the completed connecting element 6. The cut length L between the cut ends 15 and 16 of the metal strip 3 corresponds to the circumference of the connecting element 6 depicted in FIGS. 4, 5 and 6. The band material 10 or the metal strip 3 is preferably perforated prior to bending the metal strip 3, by means of which the through holes 17 are obtained, the inner contours of which are delimited by the material of the metal strip, thus by the cross webs 18 and lateral edges 19.

[0047] In the production of the connecting element 6, the metal strip is curved over a bending mandrel, not shown, into a hollow cylindrical final shape, wherein the cut ends 15 and 16 are brought together as bending ends, and subsequently joined through form fitting or preferably through welding. In the final shape depicted in FIGS. 4, 5 and 6, the metal strip 3 has a diameter D, corresponding to the outer diameter of the carrier plates 12, such that is set on the outside when the planet carrier 2 is mounted on the carrier plates 12, and is then connected thereto in a form fitting and/or material bonded manner.

[0048] The carrier plates 12 are aligned with one another prior to the attachment of the metal strip in accordance with the depiction according to FIG. 10, such that the respective axes of symmetry of the perforations 13 and 14 are oriented such that they are aligned axially to one another. The metal strip 3 is then attached to the carrier plates 12. Alternatively, the connecting bolts 20 are first installed in the connecting element, or installed simultaneously with the connecting element 6. The connecting bolts 20 are inserted into the carrier plates 4 thereby, such that each of the connecting bolts 20 is inserted into one of the perforations, and inserted into a perforation 14 of the other carrier plate 12 aligned with the first perforation 14.

[0049] Subsequently, or alternatively, the planet bolts 7 are aligned with the perforations 13 on the completed planet carrier 2, as can be seen in FIG. 12, and inserted into them, as well as through the respective planet carrier 8 and the associated planetary gear 5 thereby.

REFERENCE SYMBOLS

[0050] 1 planetary drive [0051] 2 planet carrier [0052] 3 metal strip [0053] 4 carrier element [0054] 5 planetary gear [0055] 6 connecting element [0056] 7 planet bolt [0057] 8 planet bearing [0058] 9 thrust washer [0059] 10 band material [0060] 11 central axis [0061] 12 carrier plate [0062] 13 perforation [0063] 14 perforation [0064] 15 cut end [0065] 16 cut end [0066] 17 through hole [0067] 18 cross web [0068] 19 lateral edge [0069] 20 connecting bolt