Planetary gearbox having a ring gear accommodated in a housing part

Abstract

A planetary gearbox includes a ring gear accommodated in a housing part, the ring gear particularly has on its radially outer surface, in particular its radially outer side, an annular groove, the annular groove, in particular a circumferential annular groove in the circumferential direction, and a spring element is accommodated in the annular groove, which projects at least partially into an annular groove introduced into the housing part.

Claims

1. A planetary gearbox, comprising: a housing including a first annular groove on a radially inner surface; a ring gear accommodated in the housing and including a second annular groove in a radially outer surface; and a spring element at least partially projecting into the first annular groove and the second annular groove; wherein the first annular groove includes a planar region, a normal direction of the planar region having a non-zero angle in relation to an axial direction of the ring gear, the spring element engaging the planar region.

2. The planetary gearbox according to claim 1, wherein the spring element extends substantially perpendicular to the planar region.

3. The planetary gearbox according to claim 1, wherein the first annular groove or the second annular groove is arranged as a circumferential annular groove in a circumferential direction.

4. The planetary gearbox according to claim 1, wherein the spring device is arranged as a ring and/or an apertured disk.

5. The planetary gearbox according to claim 1, wherein the spring device is circular in an axially frontal region and an axially rear region.

6. The planetary gearbox according to claim 1, wherein the spring device is arranged as an apertured disk, a smallest radial clearance value of the apertured disk at a respective axial position increases monotonically in an axial direction, and a greatest radial clearance value of the apertured disk at a respective axial position monotonically increases in the axial direction.

7. The planetary gearbox according to claim 1, wherein the spring device is arranged as an apertured disk, a smallest radial clearance value of the apertured disk at a respective axial position monotonically increases counter to an axial direction, and a greatest radial clearance value of the apertured disk at a respective axial position monotonically increases counter to the axial direction.

8. The planetary gearbox according to claim 1, wherein the spring device has a constant wall thickness.

9. The planetary gearbox according to claim 1, wherein the spring device is arranged as a punched and bent component.

10. The planetary gearbox according to claim 9, wherein the spring device is arranged as a punched and bent component produced from steel sheet.

11. The planetary gearbox according to claim 1, wherein the spring device includes a radially uninterrupted slot at a circumferential position.

12. The planetary gearbox according to claim 1, wherein the spring device includes a radially uninterrupted slot at a plurality of circumferential positions.

13. The planetary gearbox according to claim 1, wherein the spring device is axially preloaded so that the ring gear and the housing are axially pushed apart.

14. The planetary gearbox according to claim 1, wherein the spring device is axially preload so that the ring gear and the housing are axially pushed apart and such that bearings, supporting a planet gear carrier and accommodated in the housing, are pressed against a step provided on the housing and preloaded.

15. The planetary gearbox according to claim 1, wherein the angle is between 20 degrees and 70 degrees.

16. The planetary gearbox according to claim 1, wherein the spring device is toothed and/or knurled at a radially inner circumference and/or outer circumference.

17. The planetary gearbox according to claim 16, wherein the teeth of the spring device are set apart from one another at regular intervals in a circumferential direction.

18. The planetary gearbox according to claim 1, wherein the spring device is braced at a bottom of a first one of the first annular groove and the second annular groove and on the planar region of a second one of the first annular groove and the second annular groove.

19. The planetary gearbox according to claim 1, wherein planet lugs are provided in a planet gear carrier, a planetary gear being provided on each planet lug and supported by a respective bearing, a tooth system of the planetary gear meshing with an internal tooth system of the ring gear and meshing with a tooth system of a sun gear which is rotatably supported relative to the housing.

20. The planetary gearbox according to claim 19, wherein the sun gear is arranged coaxially to the planet gear carrier.

21. The planetary gearbox according to claim 1, wherein the first annular groove and the second annular groove are arranged as circumferential annular grooves in a circumferential direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a cross-section through a planetary gearbox according to an example embodiment of the present invention, ring gear 3 being connected to a housing part 1 of the planetary gearbox by a keyed connection with the aid of a spring element 2.

(2) FIG. 2 shows ring gear 3 prior to the keyed connection with the aid of spring element 2.

(3) FIG. 3 illustrates the start of the snap-in process of spring element 2 into an annular groove of housing part 1, spring element 2 sliding along a chamfer of the annular groove.

(4) In FIG. 4, spring element 2 is shown snapped into the annular groove of the housing part.

(5) FIG. 5 shows an enlarged view of FIG. 1.

(6) In FIG. 6, spring element 2 is shown in a side view, in a plan view and in an oblique view.

(7) In FIG. 7, another spring element 2 is shown in a side view, a plan view and in an oblique view.

(8) FIG. 8 shows a further spring element 2 in a plan view.

DETAILED DESCRIPTION

(9) As illustrated in FIG. 1, the planetary gearbox includes a ring gear 3 having an internal tooth system, which is situated in a housing part 1 of the planetary gearbox by a keyed connection.

(10) The tooth systems of planet gears 6 mesh with the internal tooth system of ring gear 3.

(11) Via bearings 5, in particular needle bearings, planet gears 6 are rotatably mounted on planet gear axles, which are pressed into a planet gear carrier 9.

(12) Planet gear carrier 9 is rotatably mounted in housing part 1 with the aid of two bearings 8.

(13) The tooth systems of planet gears 6 also mesh with the tooth system of a sun gear 7, which is also rotatably mounted, in particular relative to housing part 1.

(14) The axis of rotation of planet gear carrier 9 and the axis of rotation of sun gear 7 are aligned coaxially to each other.

(15) A circumferential annular groove is introduced at the outer circumference of ring gear 3; in the same manner, an annular groove is introduced into the inner side of housing part 1.

(16) As illustrated in FIGS. 2 through 4, spring element 2 is placed into the annular groove of ring gear 3 during the assembly and is elastically deformed when slipped into the bore hole provided to accommodate ring gear 3 in housing part 1, such that it is fully situated in the annular groove of the ring gear.

(17) At its one axial edge region, the annular groove introduced into housing part 1 has a chamfer, i.e. a circumferential bevel in the circumferential direction.

(18) As soon as this chamfer reaches the axial region of the annular groove of housing part 1 when ring gear 3 is inserted into housing part 1, spring element 2 begins to relax and gradually slides along the chamfer into the annular groove of housing part 1 via its first axial end region.

(19) In the relaxed state, the radial clearance region covered by spring element 2 in relation to the axis of rotation of planet gear carrier 9 overlaps both with the radial clearance region covered by ring gear 3 and the radial clearance region covered by housing part 1, in particular in the axial region covered by spring element 2.

(20) Spring element 2 may be axially preloaded so that ring gear 3 and housing part 1 are axially pushed apart. Spring element 2 therefore generates a spring force that exerts pressure on the ring gear counter to the axial direction and on the housing part in an axial direction.

(21) As illustrated in FIG. 6, spring element 2 is arranged as an apertured disk, i.e. in the form of a ring.

(22) The ring axis of the apertured disk is arranged coaxially to the axis of rotation of planet gear carrier 9.

(23) The inner diameter of the apertured disk corresponds to the smallest diameter of the annular groove introduced into ring gear 3. As a result, the inner edge of the apertured disk rests against the bottom of the annular groove introduced into ring gear 3.

(24) After the outer edge of the apertured disk has been pressed along the chamfer into the annular groove introduced into the housing part during the production while the spring element, i.e. the aperture disk, is relaxed, the outer edge of the aperture disk rests against the groove bottom of the annular groove introduced into housing part 1.

(25) Starting from the inner edge of the apertured disk towards the outer edge of the apertured disk, the radial region covered by the apertured disk increases monotonically as a function of the associated axial region covered by the apertured disk.

(26) The apertured disk may have a constant wall thickness.

(27) The radial clearance region covered by the apertured disk at a respective axial position monotonically shifts to greater radial clearances in the axial direction as a function of an increasing axial position. In other words, the smallest radial clearance value of the apertured disk at a respective axial position monotonically increases in the axial direction and the greatest radial clearance value of the apertured disk at a respective axial position monotonically increases in the axial direction.

(28) The radially outer circumference of the apertured disk may correspond to a frustoconical surface, and the radially inner circumference of the apertured disk corresponds to a frustoconical surface as well.

(29) This makes spring element 2, which is arranged as a punched and bent component from sheet metal, in particular steel sheet, easily deformable.

(30) As illustrated in FIG. 6, spring element 2 has a radially uninterrupted slot at a circumferential position for an easier deformation. The deformability may thus take place in a defined manner.

(31) As illustrated in FIG. 7, instead of the previously described spring element 2, it is also possible to use a spring element 2 that has a toothed or notched configuration at its radially outer edge, which again resembles an apertured disk in all other respects. The elevated areas of this tooth system are set apart from one another at regular intervals in the circumferential direction and have a rectangular shape in the circumferential direction.

(32) As illustrated in FIG. 8, spring element 2 may also have a slot, in particular a radially uninterrupted slot, at more than one circumferential position. Even better elastic deformability is thereby achievable. This additional slot may be used in the example embodiments described herein.

(33) Spring element 2 may be circular at its axially frontal region and may also be circular at its axially rear region.

LIST OF REFERENCE NUMERALS

(34) 1 housing part 2 spring element 3 ring gear, in particular ring gear having an internal tooth system 4 planet gear carrier 5 bearing, in particular needle bearing 6 planet gear 7 sun gear 8 bearing 9 planet gear carrier