There is not straight forward answer to this question. Each manufacturer has there own and in many cases different approaches to the question of exactly how the rotor systems lifting loads are transmitted to the airframe. As examples, Sikorsky utilizes thrust bearings in the main gear box to transfer the flight to the main gear box housing. The weight of the airframe is supported by the housing. Eurocopter utilizes struts from a thrust bearing on the main rotor shaft of the AS-350 to react the flight loads. The struts then support the airframe. On the Bell 206 the airframe is supported by a lift link from the bottom of the main gear box that attaches directly to a beam in the airframe structures. Additionally, the 206 has soft mounts that allow limited motion between the airframe and the main gear box. These soft mounts are attached to the honey comb roof structure but do not provide any substantial lift. There may be others on this site that can provide additional detailed information on some of the other helicopter models.