Switching aid for gear stages with shifting

Abstract

Gear stage encompassing the following: a sun wheel (37) that can be moved along the axis of the sun wheel (37) between a first position, in which the sun wheel (37) is mechanically connected to a planetary bridge (27) by a connecting device, and a second position, in which the sun wheel (37) is decoupled from the planetary bridge (27); characterized in that the connecting device comprises the following: an intermediate ring (100) which is connected to the planetary bridge (27); an elastic device (110) that connects the intermediate ring (100) to the planetary bridge (27) and is configured to allow the intermediate ring (100) to deflect radially and / or in the direction of rotation in a region between the planetary bridge (27) and the sun wheel (37).

Description

TECHNICAL AREA

[0001] The present invention relates to the technical field of transmissions, in particular the technical field of switch facilitation, especially for use in transmissions as single-wheel drives, e.g. for heavy-duty transporters or agricultural machinery. STATE OF THE ART

[0002] The invention relates to transmissions with a shifting device. An example of this is disclosed in patent document DE 10 2018 205862 A1.

[0003] Transmissions with these shifting devices are generally operated while stationary. For the shifting to function correctly, it is necessary to position the teeth of the shaft and hub so that engagement can occur. The torsional play present in the transmission facilitates the positioning of the teeth, as this allows the teeth to move into the gaps of the mating teeth.

[0004] When the shift mechanism is in the slow-speed gear, the backlash is reduced by the amount of the previous gear reductions, making engagement more difficult. Additionally, the position of the components is randomly distributed during gear backlash, meaning that it cannot be guaranteed that the components will have the opportunity to move in the correct direction.

[0005] For this reason, current solutions require active movement (in both directions) of one of the components to be coupled.

[0006] The aim of the present invention is to overcome such a problem and to create a solution that reliably enables the switching of the switching mechanism at standstill without further measures. SUMMARY

[0007] The present invention is based on the idea of ​​using a connecting device comprising an intermediate ring and an elastic device to facilitate the connection between the planetary bridge and the sun wheel.

[0008] According to one embodiment of the present invention, a gear stage is provided. The gear stage comprises a sun gear that can be moved along the axis of the sun gear between a first position, in which the sun gear is mechanically connected to a planet carrier by a connecting device, and a second position, in which the sun gear is decoupled from the planet carrier. The connecting device comprises an intermediate ring connected to the planet carrier and an elastic device that connects the intermediate ring to the planet carrier and is configured to allow the intermediate ring to deflect radially and / or in the direction of rotation in a region between the planet carrier and the sun gear.

[0009] According to a further embodiment of the present invention, a gear stage is provided, wherein the intermediate ring has an outer contour that corresponds to the inner contour of the planetary bridge, wherein there is a gap between the outer contour of the intermediate ring and the inner contour of the planetary bridge to allow the intermediate ring to deflect radially and / or in the direction of rotation.

[0010] According to a further embodiment of the present invention, a gear stage is provided, wherein the intermediate ring has an internal toothing configured to engage with an external toothing of said sun gear when said sun gear is moved from the second position to the first position, and wherein the elastic device is configured such that the forces arising between the external toothing of said sun gear and the internal toothing of the intermediate ring allow the intermediate ring to deflect.

[0011] According to a further embodiment of the present invention, a gear stage is provided, wherein the intermediate ring is connected to an internal toothing of the planetary bridge by means of a plug-in toothing.

[0012] According to a further embodiment of the present invention, a gear stage is provided, wherein the gear further comprises a retaining ring that secures an axial position of the intermediate ring.

[0013] According to a further embodiment of the present invention, a gear stage is provided, wherein the elastic device comprises a plurality of springs arranged along the circumferential surface of the intermediate ring and which preferably have a constant angular spacing.

[0014] According to a further embodiment of the present invention, a gear stage is provided wherein the springs are S-shaped.

[0015] According to a further embodiment of the present invention, a gear stage is provided, wherein the gear stage further comprises a shaft configured to provide a rotary motion to the gear stage, wherein the sun gear is rotatably mounted on the shaft.

[0016] According to a further embodiment of the present invention, a gear stage is provided, wherein the gear stage further comprises a planetary gear stage, the latter comprising an externally toothed sun gear which can be driven via the shaft, an internally toothed ring gear, and the rotatably mounted planet carrier on which at least one externally toothed planet gear is rotatably mounted, which engages with both the sun gear (18) and the ring gear. BRIEF DESCRIPTION OF THE FIGURES

[0017] The present invention is described with reference to the accompanying figures, where identical reference numerals refer to identical parts and / or to similar parts and / or to corresponding parts of the system. Regarding the figures: Fig. Figure 1 shows an axial section of a switching device according to the prior art; Fig. Figure 2 shows an axial section of a switching device according to an embodiment of the present invention; Fig. Figure 3 shows a sectional view of the switching device of Fig. 2, which come from the right side of Fig. 2 is taken. DETAILED DESCRIPTION

[0018] The present invention is described below with reference to certain embodiments as shown in the accompanying figures. However, the present invention is not limited to the specific embodiments described in the following detailed description and shown in the figures; rather, the described embodiments merely illustrate some aspects of the present invention, the scope of which is defined by the claims.

[0019] Further modifications and variations of the present invention are obvious to a person skilled in the art. The present description therefore encompasses all modifications and / or variations of the present invention whose scope of protection is defined by the claims.

[0020] In Fig. Figure 1 shows a gearbox known from PTL1. The gearbox comprises a gearbox support 5 with a mounting flange 6, with which the gearbox support can be attached to the chassis of a vehicle. The gearbox support 5 is a hollow body having outer and inner wall sections of differing diameters.

[0021] The transmission further comprises a planetary gear stage 10 and a second gear stage 11. The gear stages are driven by a motor, in this case a hydraulic motor 12 in a swashplate configuration, which is only shown in a highly schematic way in the figure, via an input shaft 13. This shaft is composed of two parts: a sleeve-shaped drive element 14 and a sun gear element 15. At one end, the sun gear element 15 has an external toothing 16 that engages over a certain distance with an internal toothing 17 of the drive element 14. The sun gear 18 of the planetary gear stage 10 is integrally formed on the sun gear element 15. The end of the sun gear element 15 with the external toothing 16 is rotatably mounted by a roller bearing 19.

[0022] The sun gear 18 meshes with several externally toothed planet gears 25, which are rotatably mounted at equal intervals on double-row roller bearings on bearing journals 26 of a planet carrier 27. In addition to the sun gear 18, the planet gears 25 also mesh with an internally toothed ring gear 28, which has a mounting flange 29 for attaching it to the rim of a wheel. The ring gear 28 thus forms the wheel-side output of the transmission. It is rotatably mounted on the outside of the transmission carrier 5, which projects into the ring gear 28 from one end face, by means of two tapered roller bearings 30 arranged in an O-arrangement. A cover 31 is inserted into the ring gear 28 at the other end face.

[0023] The planet carrier 27 is provided with an internal toothing 35, which allows it to engage with a sleeve-shaped second sun gear 37, which has external teeth 36. It is guided axially and radially via flanged pins 38, which are inserted into bores 34 of the gear carrier 5 and bear against it, and via flanged pins 39, which bear against the cover 31. The sun gear 37 is arranged coaxially with the input shaft 13.

[0024] A second rolling bearing 40 for the sun gear part 15 is installed between the sun gear 37 and the sun gear part 15 of the input shaft 13.

[0025] On the gear carrier 5, several axially aligned bearing journals 41 are formed around the input shaft 13 at equal angular intervals. Each of these journals supports an externally toothed spur gear 43 via a double-row rolling bearing arrangement 42. This spur gear meshes with both the sun gear 37 and the ring gear 28. The bores 34, for which the flanged bolts 38 serve to axially guide the planet carrier 27, are located in the bearing journals 41. The bores 34 run along the axis of the bearing journals 41.

[0026] By an axial movement of the second sun gear 37, which is not described in detail here because it was described in detail in PTL1, the internal toothing 35 of the planetary bridge 27 is inserted into the sun gear 37.

[0027] To facilitate insertion between the internal toothing 35 of the planetary gear 27 and the sun gear 37, the present invention provides a switching aid, which will be described in the following sections with reference to the Fig. 2 to 3 are described in detail.

[0028] Fig. Figure 2 shows an axial section of a switching device, taken along the axis Ax of the switching device.

[0029] As in Fig. As can be seen in Figure 2, a switching aid for the switching device is made possible by a connecting device comprising an intermediate ring 100 which is connected to the planetary bridge 27, and in particular to the internal toothing 35 of the planetary bridge 27.

[0030] The intermediate ring 100 has an outer contour 102 that corresponds to the inner contour of the planetary bridge 27, in order to allow a connection between the inner contour of the planetary bridge 27 and the outer contour 102 of the intermediate ring 100. A gap D1 is provided between the outer contour 102 of the intermediate ring 100 and the inner contour of the planetary bridge 27 (see sectional view of Fig. 3) arranged to allow the intermediate ring 100 to deflect radially and / or in the direction of rotation.

[0031] Therefore, according to the present invention, it is not necessary for the planetary bridge 27 to have internal teeth, since the connection between the inner contour of the planetary bridge 27 and the outer contour 102 of the intermediate ring 100 can be made by any contour.

[0032] Therefore, other positive-locking connections can be used instead of a splined connection. However, it is important that a gap D1 is provided between the contours to allow for deflection.

[0033] Furthermore, the connecting device includes an elastic device 110 that connects the intermediate ring 100 to the planetary bridge 27 and is configured to allow the intermediate ring 100 to deflect radially and / or in the direction of rotation in a region between the planetary bridge 27 and the sun gear 37.

[0034] As in the Fig. 2 and Fig. As shown in Figure 3, the elastic device 110 comprises a plurality of springs arranged along the circumferential surface of the intermediate ring 10. In this embodiment, the elastic device comprises three springs arranged at 120° intervals along the circumferential surface of the intermediate ring 100.

[0035] In the example shown, the springs are S-shaped. Alternatively, other springs can be used instead of the S-shaped springs 110, positioned and suitable to flexibly position the intermediate ring 100 in the planetary bridge.

[0036] As in Fig. As shown in Figure 2, a retaining ring 110 is arranged in the gearbox in such a way that it can secure an axial position of the intermediate ring 100 along the axis Ax of the input shaft 13.

[0037] The intermediate ring 100 has an internal toothing 101 configured to engage with the external toothing of the sun gear 37. In particular, the elastic device 110 is configured such that the forces arising between the external toothing of the sun gear 37 and the internal toothing 101 of the intermediate ring 100 allow the intermediate ring to deflect.

[0038] While the present invention has been described with reference to the embodiments described above, it is clear to the person skilled in the art that it is possible to implement various modifications, variations and improvements of the present invention in light of the teaching described above and within the scope of the attached claims without deviating from the scope of protection of the invention.

[0039] Furthermore, the areas in which experts are likely to be knowledgeable have not been described here in order to avoid unnecessarily obscuring the described invention.

[0040] For example, although this shift assist feature was described in combination with the transmission disclosed in PTL1, it is clear that this shift assist feature can also be used for other types of transmissions. Preferably for transmissions that are shifted while stationary.

[0041] Accordingly, the invention should not be limited by the specific illustrative embodiments, but by the scope of protection of the attached claims.

Claims

[1] Gear stage comprising the following: a sun wheel (37) that can be moved along the axis of the sun wheel (37) between a first position, in which the sun wheel (37) is mechanically connected to a planetary bridge (27) by a connecting device, and a second position, in which the sun wheel (37) is decoupled from the planetary bridge (27); characterized by , that the connecting device comprises the following: an intermediate ring (100) which is connected to the planetary bridge (27); an elastic device (110) that connects the intermediate ring (100) to the planetary bridge (27) and is configured to allow the intermediate ring (100) to deflect radially and / or in the direction of rotation in a region between the planetary bridge (27) and the sun wheel (37). [2] Gear stage according to claim 1, wherein the intermediate ring (100) has an outer contour (102) that corresponds to the inner contour of the planetary bridge (27), wherein there is a gap (D1) between the outer contour (102) of the intermediate ring (100) and the inner contour of the planetary bridge (27) to allow the intermediate ring (100) to move radially and / or in the direction of rotation. [3] Gear stage according to one of claims 1 or 2, wherein the intermediate ring (100) has an internal toothing (101) configured to engage with an external toothing of said sun gear (37) when said sun gear (37) is moved from the second position to the first position, and wherein the elastic device is configured such that the forces arising between the external toothing of said sun gear (37) and the internal toothing (101) of the intermediate ring (100) allow the intermediate ring (100) to deflect. [4] Gear stage according to one of claims 1 to 3, wherein the intermediate ring (100) is connected by a splined connection to an internal toothing of the planetary bridge (27). [5] Gear stage according to one of claims 1 to 4, wherein the gear stage further comprises a retaining ring which secures an axial position of the intermediate ring (100). [6] Gear stage according to one of claims 1 to 5, wherein the elastic device (110) comprises a plurality of springs arranged along the circumferential surface of the intermediate ring (100) and which preferably have a constant angular spacing. [7] Gear stage according to claim 6, wherein the springs are S-shaped. [8] Gear stage according to any one of claims 1 to 7, wherein the gear stage further comprises a shaft (13) configured to provide a rotary motion to the gear stage, wherein the sun gear (37) is rotatably mounted on the shaft (13). [9] Gear stage according to claim 8, wherein the gear stage further comprises a planetary gear stage (10), the latter comprising an externally toothed sun gear (18) which can be driven via the shaft (13), an internally toothed ring gear (28), and the rotatably mounted planet carrier (27) on which at least one externally toothed planet gear (25) is rotatably mounted, which engages with both the sun gear (18) and the ring gear (28).

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