The invention relates to a module (6) for primary parts (12) of synchronous motors (7, 8, 13) which are excited by permanent magnets, which comprise at least one secondary part (9) which is at least sectionally devoid of permanent magnets. Said secondary part (9) is made of an iron structure comprising teeth (11) which leads to the primary part (12). Said module (6) comprises at least one permanent magnet (1, 14) and at least one iron rod (2) which is arranged on the opposite sides. Recesses (3) are arranged between the iron rod (2) on one side and at least one winding (5) is guided about the iron rod (2). An additional module (6) can be secured at least to one side of the module (6) such that the iron rod (2) engages in the recesses (3) of the adjacent module (6) and the modules (6) can be placed together in relation to various predetermined primary parts (12).