Ring gear carrier for planetary gear transmission and planetary gear transmission

Abstract

The invention relates to a ring gear carrier (3) for accommodating a ring gear (8) in a transmission housing (2) of a planetary gear transmission (1), wherein the ring gear carrier (3) comprises a base carrier (11), at least one accommodating surface (13, 14) being formed on the inner side (23) of the base carrier (11), and wherein a damping element (12) is arranged on the outer side (24) of the base carrier (11) facing away from the accommodating surface (13, 14). The invention also relates to a planetary gear transmission (1) having such a ring gear carrier (3).

Description

Technical Field

[0001] The invention relates to a ring gear carrier for a ring gear of a planetary gear transmission and a planetary gear transmission having such a ring gear carrier. Background Art

[0002] In the transmission, system-related noise is generated due to internal vibration excitation. The main noise source is the tooth flanks of the meshing gears rolling under load, because the forces and moments that occur during rolling cause vibration excitation, which is perceived by the machine user, especially the passengers of the motor vehicle, as transmission noise or transmission chirping. In addition, noise can also occur at other locations in the transmission, for example when rolling bodies roll in rolling bearings. This noise generated in the transmission is transmitted as structure-borne sound via the gears, transmission shafts and bearings to the transmission housing and is output from there to the surrounding environment as airborne sound or is further transmitted to the machine structure in the form of structure-borne sound. In addition, in a planetary gear transmission, when the ring gear is connected to the transmission housing or the ring gear carrier, structure-borne sound transmission can occur via the ring gear of the planetary gear transmission, and the structure-borne sound can be transmitted to the transmission housing via the ring gear.

[0003] In order to reduce the noise generation in the transmission, measures can be taken to minimize the vibration excitation, which are referred to as primary measures. Secondary measures can also be taken to reduce the transmission of sound waves to the transmission housing or the emission of sound waves from the transmission housing of the transmission. For example, the optimization of the stiffness curve of the tooth flanks and the reduction of deviations between the tooth flanks belong to the primary measures. However, these usually lead to a significant increase in manufacturing costs, since these measures are accompanied by lower manufacturing tolerances and the associated higher component processing times. In addition, these measures cannot contribute to the reduction of noise under all load conditions, making these primary measures generally unsuitable as the only measures for noise reduction.

[0004] Different types of isolation and damping measures and measures aimed at changing the natural vibration characteristics of components that are significantly involved in the generation and conduction of structure-borne sound are secondary measures, by which the transmission of sound waves to the housing and the radiation of sound waves are to be minimized. One possibility for reducing noise is to acoustically isolate the bearing support of the transmission shaft from the transmission housing, thereby minimizing the transmission of vibrations via the bearing support. In a similar manner, such decoupling and damping measures can also be implemented on other components, such as the ring gear of a planetary gear transmission. However, such decoupling and damping measures lead to a significant reduction in the rigidity for connecting the elastically mounted transmission components to the transmission housing. Due to the reduced rigidity at the connection point, the transmission components are increasingly displaced relative to each other during torque transmission. This leads to increased loads on the tooth flanks of the engaged gears and the associated increased wear of the transmission components. In addition, due to the elastic mounting, increased vibration excitation can occur, resulting in increased noise generation. The fact that only individual transmission components can be isolated can also be adversely affected. Due to the reduced rigidity at the isolated connection point, the forces generated by the force transmission are supported in an enhanced manner at other connection points. As a result, a large part of the structure-borne sound waves are deflected, so that strong vibration excitation of the transmission housing and the noise pollution associated therewith continue to occur.

[0005] Known from DE 199 14 607 A1 is an oil sump for a vehicle transmission, in particular an automatic transmission of a motor vehicle. In this case, a web is provided on the oil sump, which has a higher rigidity than an oil sump made of a polymer material, in order to be able to absorb corresponding load peaks.

[0006] From DE 10 2007 013 494 A1 a cast housing for a drive or a transmission is known, in which damping elements are arranged on the outer surface of the cast housing in order to absorb vibrations of the housing and thus improve the acoustic properties of the housing.

[0007] DE 11 2008 004 241 A1 discloses a fixing structure for a transmission housing and a planetary gear transmission. In this case, an elastically deformable damping element is provided, which is arranged between the first tooth of the first gear and the first tooth of the second gear. Summary of the invention

[0008] The object of the invention is to minimize the noise generation in a planetary gear transmission.

[0009] According to the invention, this object is achieved by a ring gear carrier for accommodating a ring gear in a transmission housing of a planetary gear transmission, wherein the ring gear carrier comprises a basic carrier, on the inner side of which at least one accommodating surface is formed, and wherein a damping element is arranged on the outer side of the basic carrier facing away from the accommodating surface.

[0010] The basic carrier essentially maintains the rigidity of the ring gear carrier in comparison with a ring gear carrier made of solid metal material. Vibrations excited in the planetary transmission can be damped by the damping material on the outside of the basic carrier, so that the transmission of vibrations from the receiving point via the ring gear carrier to the transmission housing is reduced. In particular, when the ring gear and / or the rolling bearing are supported on the ring gear carrier, the basic carrier and the receiving point of the ring gear carrier are in a direct force flow, so that vibrations can be damped directly and accordingly effectively.

[0011] Advantageous improvements and developments of the ring gear carrier proposed in the present invention are possible by means of the features listed below.

[0012] In a preferred embodiment of the ring gear carrier, it is provided that the base carrier has a U-shaped section, wherein the recess of the U-shaped section is filled with a damping material. This results in a particularly effective possibility for damping, since the vibrations are absorbed directly by the damping element and thus the ring gear carrier excited by vibrations can be stabilized particularly effectively. In addition, such a ring gear carrier can be manufactured relatively simply in terms of technology, in particular by injection molding, wherein the recess of the U-shaped section is filled accordingly.

[0013] In a preferred embodiment of the invention, it is provided that the damping element is a damping material made of a polymer material. Polymer materials, in particular thermosetting plastics or thermoplastics, have a high damping effect and thus strongly damp structure-borne sound. Compared to metallic materials, damping materials have a lower modulus of elasticity. However, due to the connection of the damping material to the outer side of the ring gear carrier, this does not lead to a reduction in the rigidity at the receiving surface.

[0014] In a preferred embodiment of the invention, it is proposed that the basic carrier is made of a metal material. As a result, the basic carrier can be manufactured particularly simply and cost-effectively as a turned part, a stamped part or a deep-drawn part. Compared with damping materials made of polymer materials, metal basic carriers have a correspondingly higher modulus of elasticity and a higher bending stiffness. As a result, the ring gear or the bearings for the drive shaft and / or the planet carrier of the planetary gear transmission accommodated in the ring gear carrier are not displaced so strongly from their position under load, so that the load on the tooth flanks in the planetary gear transmission is reduced. By more firmly supporting the planetary gears and / or the drive shaft, additional damping measures can be taken to lead to a further noise reduction of the transmission noise.

[0015] In a preferred embodiment of the invention, it is proposed that the receiving surface for the ring gear is configured so that the ring gear can be received in the ring gear carrier in a rotationally fixed manner. In this case, the ring gear carrier supports the torque of the ring gear only in the torsional direction. In the radial direction, the planetary gear set is supported by a bearing bracket arranged in the ring gear carrier. By means of the polymer material on the ring gear carrier, attenuation is introduced into the ring gear carrier in the radial, axial and torsional directions. Therefore, the structure-borne sound level can be minimized. In addition, a decoupling function can be implemented on the ring gear in the torsional direction, because in this direction, the same rigidity of the housing cover does not need to be achieved without damping material.

[0016] In an advantageous embodiment of the ring gear carrier, it is provided that the material thickness of the damping material is at least twice the material thickness of the base carrier. In order to achieve a high damping effect at an acceptable weight, it is advantageous to apply the light damping material to the metallic base carrier with a correspondingly high strength. Thus, on the one hand, sufficient rigidity is achieved for supporting the ring gear and / or the drive shaft, but at the same time a correspondingly high damping effect is also achieved.

[0017] In a preferred embodiment of the invention, it is provided that the damping element is connected to the base carrier by means of a material connection, in particular in an injection molding process or by gluing the base carrier. In this case, the damping material can be connected to the base carrier in a simple and cost-effective manner in an injection molding process or a gluing process. As a result, the additional costs in production and assembly can be kept low and effective vibration damping can be achieved on the ring gear carrier.

[0018] According to the present invention, a planetary gear transmission is proposed, which has a ring gear carrier according to the present invention, a drive shaft, a ring gear and at least one planetary gear accommodated on a planetary carrier, wherein the ring gear carrier includes a basic carrier, on which at least one bearing of the ring gear and / or the drive shaft and / or the planetary carrier is supported on a receiving surface on the inner side of the basic carrier, wherein a damping element is arranged on the outer side of the basic carrier facing away from the at least one receiving surface.

[0019] In a preferred embodiment of the planetary gear transmission, it is proposed that the drive shaft carries the sun gear or is designed as a sun shaft. In particular, in a motor vehicle transmission for drive or shaft transmission, advantageous speed ratios can be achieved in this way to increase the torque and correspondingly reduce the speed.

[0020] In another preferred embodiment of the planetary gear transmission, it is proposed that the output is carried out via the planetary wheels or the planet carrier. By outputting via the planet carrier, the torque can be output to the output shaft or the differential in a simple manner.

[0021] According to the invention, a method for producing a ring gear carrier having a base carrier and a damping element is proposed, wherein the damping element comprises a polymer material applied to the base carrier of the ring gear carrier. By applying the damping material to the transmission cover, corresponding vibration damping can be achieved in existing and new structures and transmission noise can be reduced.

[0022] Unless stated otherwise in individual cases, the various embodiments of the invention mentioned in this application can be advantageously combined with one another. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described below with reference to the accompanying drawings using preferred embodiments. Identical components or components having the same function are identified by the same reference numerals. The accompanying drawings show:

[0024] Figure 1 A first embodiment of a planetary gear transmission according to the present invention is shown;

[0025] Figure 2 A ring gear carrier for such a planetary gear transmission according to the invention is shown;

[0026] Figure 3 Another embodiment of a planetary gear transmission according to the present invention is shown;

[0027] Figure 4 A further embodiment of a ring gear carrier for such a planetary transmission is shown. DETAILED DESCRIPTION

[0028] exist Figure 11 shows an embodiment of a planetary gear transmission 1 according to the invention. The planetary gear transmission 1 has a transmission housing 2, in which a ring gear carrier 3 is accommodated. The transmission housing 2 is preferably closed by a housing cover (not shown). A drive shaft 4 is arranged in the transmission housing 2, which is designed as a sun shaft 26. The drive shaft 4 engages with a set of planetary gears 6, which are arranged on a planet carrier 7. In this case, the toothing 18 on the planetary gears 6 engages both with the toothing 19 on the ring gear 8 and with the toothing 27 of the sun shaft 26. The planetary gear transmission 1 also has a ring gear 8, which is accommodated on a first seating surface 13 on the ring gear carrier 3. The drive shaft 4 is rotatably supported in the ring gear carrier 3 by means of a first rolling bearing 10. In this case, the rolling bearing 10 includes an inner ring 16 and an outer ring 17, which is arranged on the drive shaft 4 and rests on a second seating surface 14 of the ring gear carrier 3. A plurality of rolling bodies 20 are arranged between the inner ring 16 and the outer ring 17. Preferably, the planet carrier 7 is rotatably supported in the axial direction and the radial direction on the drive shaft 4. The output 9 of the planetary gear transmission 1 is realized via the planetary member 6 or the planet carrier 7. Alternatively, the drive shaft 4 can also carry a sun gear 5, which is engaged with the planetary member 6. A threaded hole 21 is formed on the transmission housing 2 to tighten the housing cover to the transmission housing 2.

[0029] The ring gear carrier 3 comprises a metallic base carrier 11, on the inner side 23 of which the receiving surfaces 13, 14 are formed. The base carrier 11 preferably has a rotationally symmetrical geometry, wherein the base carrier has a radial end section with a U-shaped section 30. A damping element 12 is arranged on the metallic base carrier 11 on the outer side 24, at least in the region of the U-shaped section 30, in order to damp vibrations transmitted to the receiving surfaces 13, 14, the damping element being in the form of a damping material 25. The metallic base carrier 11 is preferably manufactured as a stamped-bent part, a turned part or a deep-drawn part. In this case, in particular, the plate 22 can be formed into the shape of the base carrier 11 by relatively simple and cost-effective forming processes. At least one connection point 29, in particular a screw connection, is provided between the transmission housing 2 and the ring gear carrier 3, in which a threaded hole is introduced parallel to the center axis 28 of the planetary transmission 1, to which the ring gear carrier is fixed by means of fixing means, in particular screws. For this purpose, corresponding fastening openings are formed in the metal base carrier 11 of the ring gear carrier 3 , through which fastening means are guided in order to produce a force-fitting and / or form-fitting connection between the ring gear carrier 3 and the transmission housing 2 .

[0030] exist Figure 2In the component drawing, a ring gear carrier 3 for such a planetary gear transmission 1 is shown. The receiving surfaces 13, 14 on the metal base carrier 11 extend parallel to the center axis 28 of the planetary gear transmission 1, while the other surfaces extend substantially perpendicularly to the center axis. In this case, a damping material 25 is applied to the outer side 24 of the metal base carrier 11, which, on the one hand, reinforces the metal base carrier 11 in the region of the receiving surfaces 13, 14 and, on the other hand, causes a damping of the vibrations transmitted to the ring gear carrier 3. In this case, the base carrier 11 has a U-shaped extension 30 in the radially outer region, which has a recess 31, which is completely filled with the damping material 25.

[0031] exist Figure 3 In FIG. 1 , an alternative embodiment of the planetary gear transmission 1 of the present invention is shown. Figure 1 In the case of a substantially identically implemented structure, only the differences are discussed below. In this embodiment, the drive and output 9 are provided on the same side of the planetary transmission. In this case, the drive shaft 4 is rotatably supported in the planet carrier 7 of the planetary transmission 1 by means of rolling bearings 10. The planet carrier 7 is rotatably supported in the ring gear carrier 3 by means of a further rolling bearing at a second receiving surface 14, also referred to as a bearing surface 15. As described above, Figure 1 As shown, the drive is carried out via the drive shaft 4 , which is designed as a sun shaft 5 , and the output is carried out via the planet carrier 7 .

[0032] exist Figure 4 The Figure 3 The ring gear carrier 3 of the embodiment variant of the planetary gear transmission 1 shown in FIG. The geometry of the receiving surfaces 13, 14 and the metal base carrier 11 is adapted accordingly, so that the ring gear 8 can be received on the first receiving surface 13, and the rolling bearing 10 for rotatably supporting the planet carrier 7 can be received on the second receiving surface 14. In addition, a third receiving surface can be formed on the ring gear carrier 3 in order to receive and / or support another bearing for the drive shaft 4.

[0033] Instead of a metallic base carrier 11 , a base carrier 11 can also be used which is produced from another material having sufficient flexural rigidity, in particular from a ceramic material or a fiber-reinforced plastic.

[0034] Reference numerals list

[0035] 1 Planetary gear transmission

[0036] 2 Transmission housing

[0037] 3 Ring gear carrier

[0038] 4 Drive shaft

[0039] 5 Sun gear

[0040] 6 Planetary gear

[0041] 7 Planet carrier

[0042] 8 Ring gear

[0043] 9 Output

[0044] 10 Rolling bearings

[0045] 11 (Metal) basic bearing parts

[0046] 12 Damping element

[0047] 13. First receiving surface

[0048] 14 Second receiving surface

[0049] 15 Bearing bracket

[0050] 16 Inner Ring

[0051] 17 Outer Ring

[0052] 18 teeth (on the planetary gear)

[0053] 19 teeth (on the ring gear)

[0054] 20 Rolling elements

[0055] 21 Threaded holes

[0056] 22 Plate

[0057] 23 Inside

[0058] 24 Outer side

[0059] 25 Damping material

[0060] 26 Sun Axis

[0061] 27 teeth (on the sun gear)

[0062] 28 Central Axis

[0063] 29 Connection parts

[0064] 30 U-shaped

[0065] 31 recess

Claims

1. A ring gear carrier (3) for accommodating a ring gear (8) in a transmission housing (2) of a planetary gear transmission (1), characterized in that: The toothed ring carrier (3) comprises a basic carrier (11), wherein at least one receiving surface (13) is formed on an inner side (23) of the basic carrier (11), the toothed ring (8) can be received on the receiving surface (13), and wherein a damping element (12) is arranged on an outer side (24) of the basic carrier (11) facing away from the receiving surface (13), the basic carrier (11) having a U-shaped section (30), wherein a recess (31) of the U-shaped section (30) is filled with a damping material (25).

2. The ring gear carrier (3) according to claim 1, characterized in that The damping element (12) is a damping material (26) made of a polymer material.

3. The ring gear carrier (3) according to claim 1, characterized in that The basic carrier (11) is made of metal material.

4. The ring gear carrier (3) according to claim 1, characterized in that The receiving surface (13) for the ring gear (8) is designed such that the ring gear (8) can be received in the ring gear carrier (3) in a rotationally fixed manner.

5. The ring gear carrier (3) according to claim 1, characterized in that The material thickness of the damping material (25) is at least twice the material thickness of the base carrier (11).

6. The ring gear carrier (3) according to any one of claims 1 to 5, characterized in that The damping element (25) is connected to the base carrier (11) by a material fit.

7. A planetary gear transmission (1) having a ring gear carrier (3) according to any one of claims 1 to 6, the planetary gear transmission comprising a drive shaft (4), a ring gear (8) and at least one planetary gear (6) accommodated on a planet carrier (7), wherein: The ring gear carrier (3) comprises a basic carrier (11), on which at least one bearing of the ring gear and / or the drive shaft (4) and / or the planet carrier is supported on a receiving surface (13) on the inner side (23) of the basic carrier (11), wherein a damping element (12) is arranged on the outer side (24) of the basic carrier (11) facing away from at least one of the receiving surfaces (13).

8. The planetary gear transmission (1) according to claim 7, characterized in that: The output (9) is carried out via the planetary gear (6) or the planetary carrier (7).

9. The planetary gear transmission (1) according to claim 7 or 8, characterized in that: The drive shaft (4) carries the sun gear (5) or is designed as a sun shaft (26).

Images