There is described a patch pump (2) comprising a cartridge (4), a power source (6), a pump system, a drug delivery device and a control system (12) configured to operate in particular the pump system and the drug delivery device. The pump system comprises, on the one hand, a pump (14) having a pump housing (22) containing a pump piston (26) and a valve piston (28) and, on the other hand, a pump drive (16) comprising a piston motor (30) and a valve motor (31) for driving the pump piston (26) and the valve piston (28) independently from each other through a first and a second transmission (52, 54). The drug delivery device comprises a transdermal delivery system having a needle actuation mechanism configured for transdermal insertion of a cannula.
