A mixing device comprises a mixing space for mixing bone cement, at least one mixing element supported in the mixing space such that it can rotate, a gear for rotating the at least one mixing element, and at least one elastically deformable energy-storing element that is connected to the gear such that the gear can be driven by an elastic energy from the energy-storing element and such that the at least one mixing element can be rotated in the mixing space by means of the gear upon the release of elastic energy from the energy-storing element. Additionally, a vacuum mixing system and mixing method comprise the mixing device for mixing the bone cement.