The present invention relates to a coupling assembly (1) for fixedly connecting a rotational member (2) to an end section (3) of a hollow shaft (4). It may e.g. be used for connecting the main shaft (4) of a wind turbine (28) to a planet carrier (2) of a coaxial planetary gear system. The coupling assembly (1) comprises a shrink ring (6) and a coupling element (7). The shrink ring (6) has an outer diameter corresponding to the inner shaft diameter (d) and a conical surface (14) for connecting the shrink ring (6) and the coupling element (7). The coupling element (7) comprises an annular groove (18) with a groove diameter corresponding to the outer shaft diameter (D) and a conical surface (20) matching the shrink ring (6). When in use, the hollow shaft (4) is arranged in the groove (18) and connected to the coupling element (7) by axially extending bolts (9). Hereby a torque can be transferred by both the shrink connection and the bolts fastened into the hollow shaft. The coupling element (7) preferably comprises an outer flange (26) to which the rotational member (2) can be fastened.

A first embodiment of a torque tube coupler may include an outer body that includes a first abutting surface and a second abutting surface adjacent to the first abutting surface. Set screws may be inserted into one or more channels of the first abutting surface. Tightening the set screws may force the abutting surfaces away from each other and the outer body to press against an inner surface of a torque tube. Another embodiment of the torque tube coupler may include a central ring sized based on a size of a torque tube. The torque tube coupler may also include a set of fingers that extend away from a first side of the central ring and are shaped to flex radially outward. The torque tube coupler may include a core disposed within the set of fingers that, when drawn towards the central ring, causes the fingers to flex radially outwards.

A hollow shaft coupling for connecting a shaft to a hollow shaft, where the hollow shaft coupling can be arranged completely in the hollow shaft and can effect clamping both radially inwardly as well as radially outwardly. The coupling enables a first clamping unit to clamp the hollow shaft coupling radially inwardly against the shaft and a second clamping unit which is separate from the first clamping unit to clamp the hollow shaft coupling radially outwardly against the inner circumferential surface of the hollow shaft, with the two clamping units spaced apart from one another axially, and the two clamping units connected to one another via a play-free and rotationally stable coupling which is arranged between them.

A connection system includes a shaft, a hollow shaft, a press ring, a first ring fitted onto the hollow shaft, a second ring, a bearing, and a housing part. The hollow shaft is rotatably mounted via the bearing received in the housing part and has an inner conical region. The first ring has a first outer conical region and a second outer conical region. The first outer conical region is positioned against the inner conical region of the hollow shaft and/or at least a partial region of the first outer conical region is arranged radially between the shaft and the hollow shaft. The second ring encloses and/or surrounds the first ring. The press ring touches both a partial region of the radially outer surface of the hollow shaft and at least one partial region of the radially outer surface of the second ring and/or is mounted onto these partial regions.