Patent ID: 8574291
Filing Date: 2013-11-05
Classification: A61M,F04B,H02K

Abstract:
1. An electric linear drive for a pump, the drive comprising: a stationary part; a movable part, one of the parts being formed by a permanent-magnet assembly having, relative to an axis, an axially polarized inner permanent magnet and an axially polarized outer permanent magnet each having a pair of axially opposite ends and together forming an axially extending air gap, the other of the parts being formed by a coil assembly having a single winding whose orientation reverses at least once axially; respective inner and outer pole shoes at the axial ends of the inner and outer permanent magnets and axially spaced at the air gap such that the pole shoes concentrate a magnetic field of the permanent magnets in the air gap and a magnetic circuit is formed such that at one axial end of the permanent magnets the magnetic field lines extend through the air gap radially from the inside to the outside and at the other axial end through the air gap from the outside to the inside; and a force-transmission element extending in the air gap and connected to the movable part and to at least one pump chamber, whereby when an electrical current is applied to the coil assembly the element is shifted axially.