Abstract: A drive unit for a motor metering pump and a metering pump, including a drive chamber and a drive shaft arranged in the drive chamber. The drive shaft is rotated about a longitudinal axis in a direction of rotation during operation of the drive unit, the drive unit includes a bearing in which the drive shaft is mounted. The drive chamber is filled with a lubricant up to a filling level during operation of the drive unit, and the bearing is arranged above the filling level in the direction of the longitudinal axis. The drive shaft has 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 in such a way that, during operation of the drive unit, lubricant is transported from the first point to the second point.

Abstract: A dosing pump for conveying a fluid, having a displacement element and a dosing chamber, the displacement element delimiting the dosing chamber and being movable back and forth on a movement axis between a pressure position and a suction position, a drive being able to apply a driving force to the displacement element in the direction of the pressure position. A restoring force is exerted on the displacement element in the direction of the suction position by a biasing element. A stop element is provided which limits the movement of the displacement element in the direction of the suction position, and the stop element can be adjusted along the axis of movement via a control element which can be moved along a control axis in order to set a dosing volume of the dosing pump.

Abstract: The present invention relates to a check valve, and to a device having a check valve, and to a method of cleaning a check valve. In order to provide a check valve or a device having a check valve or a method of cleaning a check valve, in which sufficient cleaning of the non-flow-facing regions of the valve closing body is also ensured, it is proposed according to the invention that an element reducing the flow cross-section is provided in a region of the opening stop in addition to the opening stop so that, when the valve closing body is in the open position and the fluid flows through the check valve counter to the blocking direction, a non-flow-facing region of the surface of the valve closing body has at least an average wall shear stress of 50% compared to an average wall shear stress of a flow-facing region of the surface of the valve closing body.