A driving device of a metering and mixing apparatus for multi-componentsubstances, which has at least two holders for holding interchangeablecartridges,a discharging apparatus for the simultaneous discharging of the substancecomponents from the cartridges by discharging pistons entering the cartridgeholder or cartridges, wherein at least one discharging piston has a threadwhich,can generate a forward propulsion of said piston, and a mixing apparatus whichmixes and discharges the discharged substance components in mixed form, agear unit for connection of a drive motor and a spindle-like discharging rodof thepiston provided with the thread, a rear part of the longitudinal extent of therod hasa spirally toothed, non-self-locking spindle section and, at the front end, anengagement element for engaging in the piston, wherein the gear unit has adrivenwheel with an internal spiral toothing matched to the toothing of the spindlesection
