Tiltable planetary carrier

Abstract

Arrangement comprising a planetary stage, a shaft (101) and a connecting element (119) which forms a rotationally fixed connection of a planet carrier (115) of the planetary stage with the shaft (101) and is designed to be compliant with respect to tilting of the planet carrier (115) relative to the shaft (101); wherein a central axis of a ring gear (113) of the planetary stage is tilted relative to a rotational axis (123) of the shaft (101); characterized in that the shaft (101) carries the planet carrier (115) via the connecting element (119).

Description

[0001] The invention relates to an arrangement according to the preamble of claim 1.

[0002] DE 10 2017 223 356 A1 discloses a planetary carrier connected to a shaft by means of a connecting element. The connecting element is designed to be flexible with respect to tilting of the shaft and the planetary carrier relative to each other. The shaft is mounted in a structure fixed to the housing. A ring gear is fixed in the same structure, which, together with the planetary carrier, forms part of a planetary stage. Due to the flexibility of the connecting element, the planetary carrier is supported in the ring gear via planetary gears. This results in increased loads in the toothing of the planetary gears and the ring gear.

[0003] DE 10 2010 029 071 A1 discloses a wheel drive for driving a wheel of a vehicle. The wheel drive comprises an electric drive motor for generating a drive torque, a transmission for increasing the drive torque, and a drive shaft with at least one joint for transmitting the increased drive torque to the wheel.

[0004] DE 10 2017 223 356 A1 discloses a planetary carrier supported by the input shaft of a wind turbine gearbox. The planetary carrier is supported exclusively by two bearings on the input shaft.

[0005] The invention is based on the object of non-rotatably connecting a planetary carrier to a shaft while avoiding the disadvantages inherent in the prior art solutions. This object is achieved by an arrangement according to claim 1. Preferred developments are contained in the subclaims and will become apparent from the following description.

[0006] The arrangement according to the invention comprises a planetary carrier, a shaft, and a connecting element. A planetary carrier refers to a means for receiving and supporting planetary gears. The planetary gears are rotatably mounted in the planetary carrier. Together with the planetary carrier, they form part of a planetary stage, which also includes a ring gear and a sun gear. The planetary gears mesh with the ring gear and / or the sun gear. Exactly two of the three components—ring gear, planetary carrier, and sun gear—are rotatably mounted relative to a housing or a structure fixed to the housing, while the third component is non-rotatably fixed in the housing or the structure fixed to the housing.

[0007] This is suitable for use in a wind turbine gearbox, for example. Preferably, an input shaft of the wind turbine gearbox corresponds to the aforementioned shaft.

[0008] The shaft is a rotatably mounted element in the housing or the structure fixed to the housing, designed to transmit torque. In particular, it can be an input shaft that transmits the input torque of a transmission to the planetary carrier.

[0009] The connecting element forms a rotationally fixed connection between the planet carrier and the shaft. Specifically, the connecting element is rotationally fixedly connected to both the shaft and the planet carrier. Thus, there are rotationally fixed connections between the connecting element and the shaft, as well as between the connecting element and the planet carrier. In particular, the connecting element can be integrally connected to the shaft and / or the planet carrier.

[0010] The connecting element is designed to be flexible with respect to tilting of the planet carrier relative to the shaft. Tilting refers to rotations around a radial axis, i.e., one that runs orthogonally to a rotational axis of the shaft and the planet carrier. In the tilted state, the rotational axes of the shaft and the planet carrier run antiparallel to each other. The angle formed by the two rotational axes in the tilted state is different from 180°. Therefore, in the tilted state, the two rotational axes are not aligned.

[0011] A connecting element designed to be resilient to tilting within the meaning of the invention is an element that is designed to be resilient to tilting through structural measures. In particular, its resilience to tilting is greater than the resilience of the input shaft and the planetary carrier. The connecting element can resist the tilting. However, this resistance is less than the resistance that the input shaft and the planetary carrier offer to the same tilting. The connecting element therefore acts as a torsion spring whose spring axis runs orthogonal to the rotational axis of the input shaft and the planetary carrier.

[0012] The flexibility of the connecting element can be achieved in various ways. Corresponding developments are described in DE 10 2017 223 356 A1, the content of which is therefore incorporated herein by reference.

[0013] To prevent the planet carrier from resting on the toothing of the ring gear via its planetary gears, a central axis of the ring gear is tilted relative to the shaft's axis of rotation. The central axis of the ring gear and the shaft's axis of rotation are therefore not aligned and do not run parallel to each other, but are at an angle to each other other than 180°. Starting from an aligned course of the two axes of rotation, they are rotated relative to each other around an axis that runs radially, i.e., orthogonally to the central axis of the ring gear and the shaft's axis of rotation.

[0014] The central axis of the ring gear is identical to one of the toothing axes of its gearing. This is characterized by the fact that the ring gear is rotationally symmetrical with respect to a rotation through several angles around the central axis. The number of angles corresponds to the number of teeth of the ring gear. The ring gear can be mounted in a rotationally fixed manner or rotatably with respect to a housing or a structure fixed to the housing. In the latter case, the central axis of the ring gear is identical to its axis of rotation.

[0015] Tilting the ring gear allows the position of the ring gear to be aligned with the tilt of the planet carrier. This prevents the planet carrier from resting on the toothing of the ring gear via its planetary gears. This relieves the load on the meshing toothing of the planetary gears and the ring gear, and a more even distribution of the loads acting on the individual tooth flanks is achieved.

[0016] According to the invention, the shaft supports the planetary carrier via the connecting element. This means that the weight acting on the planetary carrier is at least partially supported by the connecting element in the shaft. The weight acting on the planetary carrier includes its own weight, the weight of its planetary gears, planetary pins, and planetary bearings.

[0017] Thanks to the invention, the planetary carrier is at least partially supported by the shaft bearings. This eliminates the need for bearings for the planetary carrier. Their function is now taken over by the shaft.

[0018] In a preferred embodiment, the planetary carrier is supported exclusively by the shaft. This means that the planetary carrier does not have its own bearings, but is supported exclusively by the shaft's bearings. According to this embodiment, its weight is fully supported by the connecting element on the shaft.

[0019] The improved elimination of bearings in the planetary carrier allows the planetary carrier to align itself with the gear teeth of the ring gear and a sun gear of the same planetary stage. This improves the load-bearing behavior of the gear teeth. However, the weight force acting on the planetary carrier causes its center axis to tilt relative to the shaft's rotational axis. This tilt is compensated for by the invention, as described above.

[0020] In a preferred embodiment, the tilting of the ring gear is oriented toward the tilting of the planet carrier. According to the embodiment, the center axis of the ring gear is tilted relative to the shaft's axis of rotation by the same angle by which a center axis of the planet carrier is tilted relative to the shaft's axis of rotation. In particular, the center axis of the planet carrier can be tilted relative to the shaft's axis of rotation due to the weight acting on the planet carrier. According to the embodiment, the center axis of the ring gear and the center axis of the planet carrier run parallel to each other. In particular, the two axes can be congruent. This embodiment enables complete compensation of the weight-induced deformations of the connecting element due to its flexibility.

[0021] Preferred embodiments of the invention are illustrated in the figures. In detail: Fig. 1 a section of a gearbox.

[0022] The Fig. The section shown in Figure 1 is part of a wind turbine gearbox. An input shaft 101 of this gearbox is mounted in a housing 103. The housing 103, in turn, is fixed in a nacelle 105 of the wind turbine.

[0023] The housing 103 includes an input shaft housing 107, in which bearings 109 of the input shaft 101 are mounted, and an intermediate piece 111. Another part of the housing 107 is a ring gear 113. This is fixed in the input shaft housing 107 via the intermediate piece 111.

[0024] The ring gear 113 belongs together with a planet carrier 115, planet gears 117, which are rotatably mounted in the planet carrier 115, and a Fig. 1, a sun gear (not shown) forms a planetary stage. The planetary gears 117 mesh with the ring gear 113 and the sun gear.

[0025] The planet carrier 115 forms a connecting element 119. This is bolted into the input shaft 101. The planet carrier 115 does not have its own bearing, but is fully supported by the connecting element 119 in the input shaft 101.

[0026] As described in DE 10 2017 223 356 A1, the connecting element 119 is designed to be flexible with respect to tilting of the planet carrier 115 relative to the input shaft 101. This results in a tilting of the planet carrier 115 due to weight, so that a rotational axis 121 of the planet carrier 115 and a rotational axis 123 of the input shaft 101 are not aligned. This misalignment is compensated by a corresponding tilting of the ring gear 113. The ring gear 113 is tilted such that its central axis corresponds to the rotational axis 121 of the planet carrier 115.

[0027] Preferably, the ring gear 113 is designed like a conventional ring gear, rotationally symmetrical to its central axis. The tilting of the ring gear 113 is achieved by adapting the intermediate piece 111. Thus, a flange 125, which the center piece 111 forms for receiving and securing the ring gear 113, is tilted relative to the rotational axis 123 of the input shaft 101 such that a central axis of the flange 125 corresponds to the rotational axis 121 of the planet carrier 115. Reference symbol 101 Input shaft 103 housings 105 Gondola 107 Input shaft housing 109 warehouses 111 Intermediate piece 113 ring gear 115 planet carrier 117 Planetary gear 119 Connecting element 121 Planet carrier rotation axis 123 Input shaft rotation axis 125 flange

Claims

[1] Arrangement with a planetary stage, a shaft (101) and a connecting element (119) which forms a rotationally fixed connection of a planet carrier (115) of the planetary stage to the shaft (101) and is designed to be flexible with respect to tilting of the planet carrier (115) relative to the shaft (101); wherein a central axis of a ring gear (113) of the planetary stage is tilted relative to a rotational axis (123) of the shaft (101); characterized by that the shaft (101) carries the planet carrier (115) via the connecting element (119). [2] Arrangement according to the preceding claim; characterized by that the planet carrier (115) is carried exclusively by the shaft (101). [3] Arrangement according to one of the preceding claims; characterized bythat the central axis of the ring gear (113) is tilted relative to the axis of rotation (123) of the shaft (101) by the same angle by which a central axis (121) of the planet carrier (115) is tilted relative to the axis of rotation (123) of the shaft (101) as a result of the weight force acting on the planet carrier (115).

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