Drive unit for motor dosing pump

A drive unit for a motor metering pump, comprising:

• a drive chamber;
• a drive shaft arranged in the drive chamber, wherein the drive shaft is rotated in a direction of rotation about a longitudinal axis during operation of the drive unit;
• a bearing in which the drive shaft is mounted, wherein the drive chamber is filled with a lubricant up to a filling level during the operation of the drive unit, wherein the bearing is arranged above the filling level in the direction of rotation about the longitudinal axis, wherein the drive shaft comprises:
• a conveying channel for the lubricant which extends from a first point below the filling level to a second point above the filling level and is arranged such that during the operation of the drive unit lubricant is transported from the first point to the second point, wherein the conveying channel is formed as a recess in a lateral surface of the drive shaft, the conveying channel has a first boundary wall which delimits the conveying channel in an outward radial direction perpendicular to the longitudinal axis such that an undercut is formed, the conveying channel comprises the first boundary wall, a channel guide wall and a secondary boundary wall, both the first boundary wall and the second boundary wall extend along the longitudinal axis and do not lie in a plane with the channel guide wall, and the conveying channel is configured to inhibit radial escape of the lubricant within the recess by virtue of undercut geometry during rotation of the drive shaft.