An electromagnetic induction pump includes a tubular internal inductor having internal combs and internal coils between teeth of the internal combs. The inside of the internal inductor forms a cavity. An internal tube is positioned around the internal inductor. A pumping canal allows circulation of a fluid. The canal is between the internal tube and external tube. A tubular external inductor is positioned around the external tube and includes external combs and external coils positioned between teeth of the external combs. An electromagnetic pump includes a movement device for moving the internal combs, and varies the radial clearance between the internal combs and internal tube, having a first part positioned inside the internal inductor and in connection with the internal combs to move them radially, and a second part extending at least partially outside of the internal inductor and connected to the first part to control the first part.