Abstract
The invention relates to an electrical linear drive, in particular for a pump system of an artificial heart, with a movable part and a stationary part, wherein the stationary part is formed by a permanent magnet arrangement and the movable part is formed by a coil arrangement, or vice versa, and wherein the coil arrangement and the permanent magnet arrangement can be moved to and fro relative to each other in an axial direction by means of current passed through the coil arrangement, wherein the coil arrangement (1) is arranged in an axially extending air gap (5) of the permanent magnet arrangement (2) whose magnetic material is magnetized in the axial direction and which, at least at its two axial ends, has inner and outer pole shoes (6a, 6b) which lie radially opposite each other and are spaced apart by the air gap (5), as a result of which the magnetic field in the air gap (5) is concentrated in the radial direction in the area of the mutually facing pole shoes (6a, 6b), as a result of which at least one magnetic circuit is formed in which the magnetic field lines extend radially through the air gap (5) from the inside outwards and also through said air gap (5) from the outside inwards. The invention further relates to an electrical linear drive of this kind in which the permanent magnet arrangement (2) is designed as a stack of frame-shaped, in particular ring-shaped magnets (2a, 2b, 2c), which are magnetized alternately radially and axially in the axial direction, such that the magnetic field is strengthened on one side of the frame or in particular ring, in particular on the radially outer side, and is weakened on the other side of the frame or in particular ring, in particular on the radially inward side, and the coil arrangement (1) is arranged coaxially with respect to the permanent magnet arrangement (2) on the side with the strengthened magnetic field.