Oscillating-piston drive for a vacuum pump and an operating method for said drive

An oscillating-piston drive for a vacuum pump (1) with a piston (2), which presents has two piston sections (3,4) and an intermediate zone provided with a drive magnet (11). Cylinder sections (8, 9) slidingly receive the piston sections (3, 4). An annular recess (12) is defined between the cylinder sections (8, 9) at a central yoke (19). The recess provides space for movement of the drive magnet (11). An electromagnetic drive which surrounds the piston (2) includes yoke components (17, 18, 19) and coils (15, 16) situated to the sides of said central yoke. Negative influences on the delivery rate of the pump are reduced by a can (34) which delimits the recess (12) peripherally or by controlling the current supply to the coils, such that only one coil conducts current at a time.