Epicyclic gearing with a gearing housing

A planet stage of an epicyclic gearing includes a gearing housing with a ring gear arranged in a fixed position, at least two planet wheels mounted in a planet web that has at least one cheek, and a sun wheel. The planet web is connected to an input shaft, and there is a connection between the input shaft and a component of a further planet stage. The planet stage of the epicyclic gearing, in particular the planet web, has a reduced torsional loading. The reduced torsional loading is achieved in that the connection is a connecting web which is connected to that cheek of the planet web which is acted upon by an admission of load/moment, and is arranged in the region between two planet wheels and within the ring gear.

This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2012/004432, filed on Oct. 24, 2012, which claims the benefit of priority to Serial No. DE 10 2011 118 832.4, filed on Nov. 18, 2011 in Germany, the disclosures of which are incorporated herein by reference in their entirety.

BACKGROUND

The disclosure relates to a planetary stage of a planetary gear mechanism having a gear mechanism housing, in which a fixedly arranged internal gear, at least two planetary gears which are mounted in a planet spider which has at least one cheek, and a sun gear are arranged, the planet spider being connected to an input shaft, and there being a connection between the input shaft and a component of a further planetary gear mechanism.

A planetary gear mechanism of this type having a plurality of planetary stages is known from WO2008/104258 A1. The planetary gear mechanism is designed for a wind power plant which converts kinetic energy of the wind into electrical energy and feeds it into a power network. The planetary stages of the planetary gear mechanism interact with one another, a division of load taking place from a rotor shaft to a first planetary stage and, around the outside of the internal gear of the first planetary stage, to a second planetary stage. This configuration enlarges the overall volume of the planetary gear mechanism and therefore increases the weight of the planetary gear mechanism as a result of the necessary solid configuration. In addition, the running behavior of the planetary gear mechanism is influenced in a disadvantageous manner as a result of the high masses which are to be moved.

A further planetary gear mechanism is known from EP 1 240 443 B1. Said planetary gear mechanism likewise has a first planetary stage which is connected to a rotor shaft, in which first planetary stage the planet spider of the first planetary stage is connected to the internal gear of a second planetary stage. This embodiment is generally customary and is used in planetary gear mechanisms which are installed, for example, in wind power plants.

SUMMARY

The disclosure is based on the object of providing a planetary stage of a planetary gear mechanism, in which the torsion loading of a planet spider of the planetary stage is reduced.

This object is achieved by virtue of the fact that the connection is a connecting web which is arranged in the region between two planetary gears and within the internal gear and is connected to the cheek of the planet spider, which cheek is loaded by an introduction of load/torque. In this embodiment, the load which is to be transmitted to a further planetary stage is guided as a result past the planet spider of the first planetary stage in the region between two planetary gears and is transmitted to the further planetary stage. As a result, firstly no load routing around the internal gear of the first planetary stage is necessary, and the first planet spider is loaded only by its own torsion which leads at least to reduced tilting and/or oblique positioning of the planetary gear bolts of the first planetary stage.

In one development of the disclosure, the number of connecting webs corresponds to the number of planetary gears. In particular, the first planetary stage of the planetary gear mechanism has three planetary gears, and three connecting webs are correspondingly provided between the planetary gears within the internal gear. This configuration has proven particularly suitable for connecting the second planetary stage to the first planetary stage.

In a further embodiment of the disclosure, the connecting web is configured in one piece with that cheek of the planet spider which is loaded by the introduction of load/torque. The planet spider and the connecting web or the connecting webs are preferably configured as a single-piece cast part, it being possible for the connecting webs to be produced by way of a simple modification of the corresponding casting mould.

In a further embodiment of the disclosure, a division of load/torque to the connecting web and to the planet spider or to the opposite cheek of the planet spider takes place in the cheek which is loaded with the introduction of load/torque. If, for example, the planetary stage is part of a wind power plant gear mechanism, as will be explained in the following text, the cheek which is loaded by the introduction of load/torque is connected to the rotor side and the opposite cheek is connected to the generator side of the wind power plant (in each case if required via further gear mechanism stages or planetary stages). In summary, the division of load/torque according to the disclosure therefore takes place within the internal gear diameter of the planetary stage, as it were in the “empty spaces” between the planetary gears, and does not enlarge the overall volume.

In one development of the disclosure, the connecting webs are connected to a connecting ring. The connecting ring can be configured as a continuous closed ring or else as an interrupted ring in the form of ring segments. The connecting ring is correspondingly arranged on the opposite side to the cheek which is loaded by the introduction of load/torque, and, for unproblematic assembly, has an external diameter which is smaller than the internal diameter of the internal gears of the first and also the second planetary stage. The assembly of the planetary gear mechanism with the individual planetary stages is therefore not impeded in any way. The connecting ring with a total of three connecting webs is preferably configured as a single-piece cast part, whereby the input shaft, the planet spider (with the two cheeks), the connecting webs and the connecting ring are therefore configured in one particularly advantageous embodiment as one component in the form of a machined cast part.

In one development of the disclosure, the connecting web or the connecting ring is connected to an internal gear or a planet spider of the further planetary stage via a positively locking or frictional connection, in particular via a plug-in connection. A connection of this type contributes to unproblematic assembly of the individual gear mechanism stages, it being possible for the latter to be arranged, for example, in independent housing components.

In a further embodiment of the disclosure, the plug-in connection is configured as an externally toothed ring which is formed on the connecting ring and as an internally toothed ring which is arranged on the internal gear or the planetary gear carrier. This combination has proven particularly suitable, both the production and the assembly being simplified as a result.

In one development of the disclosure, the planetary gear mechanism having the planetary stage which is configured according to the disclosure is a continuous flow power plant gear mechanism, in particular an ocean current power plant gear mechanism or a wind power plant gear mechanism. A wind power plant is particularly preferably equipped with a wind power plant gear mechanism of this type.

DETAILED DESCRIPTION

FIG. 1shows a side view of a wind power plant1with its essential assemblies. The wind power plant1has a tower2, on which a nacelle3, in the form of a machine housing, which is mounted such that it can be rotated about a vertical axis, is arranged. A gear mechanism4is fastened in a rotationally fixed manner in the nacelle3, the gear mechanism4having a drive shaft5and an output shaft6. The drive shaft5of the gear mechanism4is connected to a hub7of a rotor which has a plurality of rotor blades8. The output shaft6is rotationally connected to a drive apparatus to be driven in the form of a generator9. The gear mechanism4is designed in such a way that it converts a slow rotational movement of the drive shaft5into a rapid rotational movement of the output shaft6. Electrical energy is generated by means of the wind power plant1, by the rotor which is set in rotational movement by the wind introducing the rotational movement via the drive shaft5into the gear mechanism4. The gear mechanism4has, in particular, a planetary gear mechanism with a first planetary stage10and a second planetary stage which are connected to a summing gear mechanism. The summing gear mechanism is connected to the output shaft6, optionally via a spur gear mechanism, and converts the rotational movement into a more rapid rotational movement. Finally, the rapid rotational movement is transmitted via the output shaft6to the generator9in order to generate power.

FIG. 2shows an end-side sectional illustration of the planetary stage10as a constituent part of the gear mechanism4. The planetary stage10has an input shaft11which is connected directly or via a spur gear mechanism to the drive shaft5. The input shaft11is connected to a planet spider12, in particular is configured in one piece as a cast part. The planet spider12is of approximately annular configuration and has a total of three bores13which are arranged on the circumference of the planet spider12and into which planetary gear bolts14(see alsoFIG. 3) are inserted. Planetary gears15are mounted on the planetary gear bolts14via planetary gear bearings16a,16b. The planet spider12is composed of two cheeks27a,27bwhich are connected to one another. The cheek27afaces the introduction of load/torque (that is to say the rotor side), whereas the cheek27bfaces the generator side. The cheeks27a,27bare connected via what are known as small heart-shaped formations17which serve primarily for said connection of the cheeks27a,27band secondarily for the supply of lubricant to the gearwheels which mesh with one another, namely an internal gear23, three planetary gears15and a sun gear18(FIG. 3).

Connecting webs19which protrude through the planet spider12and the cheek27bare formed integrally on the cheek27aof the planet spider12. The connecting webs19are connected on the side of the cheek27bto a connecting ring20or are configured in one piece, preferably as a cast part.

According toFIG. 3, the connecting ring20is provided with an external toothing system21which interacts with an internal toothing system22, in particular of an internal gear of a second planetary stage which is not shown in further detail. Here, the external toothing system21is configured in such a way that it can be plugged through the internal gear23of the first planetary stage10. The internal gear23of the first planetary stage10is arranged in a rotationally fixed manner in the housing of the gear mechanism4via a torque support24. A first bearing25aand a second bearing25b, in which the planet spider12or the input shaft11is mounted, are arranged in the housing and the torque support24. If the input shaft11is moved rotationally, the planetary gears15run on the stationary internal gear23and set the sun gear18in a rotational movement which is transmitted preferably to a summing gear mechanism, via a sun gear shaft26. At the same time, the internal gear of a second planetary stage is driven via the rotationally moved input shaft11by way of the connection according to the disclosure, which internal gear has a stationary planetary gear carrier. In the second planetary stage, correspondingly, a rotational movement is exerted on a sun gear of the second planetary stage which is likewise connected to the summing gear mechanism. Here, the sun gear of the second planetary stage is connected to a hollow shaft of the summing gear mechanism, whereas the sun gear18of the first planetary stage10is connected to a planetary gear carrier of the summing gear mechanism. The summed rotational movement is correspondingly output via a sun gear of the summing gear mechanism to the output shaft6.

LIST OF DESIGNATIONS