An electromagnetic drive device comprises a drive part (10) arranged to be
reciprocated in the stroke direction (H) and possessing a circular or
oval cross section, said drive part having a permanent magnet arrangement
magnetized athwart the stroke direction (H), such arrangement possessing
at least one pair of oppositely magnetized magnet portions (11 through
14) arranged sequentially in the stroke direction and being arranged in
the intermediate space of a yoke arrangement (16) with pole pieces (19
through 22) provided in the direction of magnetization on opposite sides
of the drive part (10). The yoke arrangement (16) possesses two pairs of
pole pieces (19 through 22) delimiting the intermediate space and which
are joined together by two yoke regions (23 and 24) extending essentially
in parallelism to the stroke direction (H). At least one of the yoke
regions (23 and 24) is surrounded by a coil (25 and 26) able to conduct
current for performing a stroke. Each pair of pole pieces (19 and 21 and
respectively 22 and 22) is provided with a pair of oppositely magnetized
magnet portions (11, 12; 32, 33 and, respectively, 13, 14; 34, 35) of the
permanent magnet arrangement. This means that it is simple to design for
an extremely narrow overall size.