Pump for conveying a liquid, in particular an exhaust-gas cleaning additive

Abstract

The invention relates to a pump (1) for conveying a liquid, comprising at least one pump housing (2), which has at least one inlet (3) and at least one outlet (4) and an inner circumferential surface (13) and a geometric axis (53), wherein an eccentric (5), which can be rotated about the geometric axis (53) in relation to the pump housing (2), is arranged within the pump housing (2), wherein a deformable element (7) is arranged between the inner circumferential surface (13) of the pump housing (2) and the eccentric (5) and wherein a conveying channel (8) from the at least one inlet (3) to the at least one outlet (4) is formed by means of the deformable element (7) and the inner circumferential surface (13) of the pump housing (2) and wherein furthermore the deformable element (7) is pressed against the pump housing (2) by the eccentric (5) in some sections in such a way that at least one movable seal (9) of the conveying channel (8) and at least one closed pump volume (10) in the conveying channel (8) are formed, which at least one seal and at least one closed pump volume can be moved in order to convey the liquid along the conveying channel (8) from the inlet (3) to the outlet (4) by means of a rotational motion of the eccentric (5), wherein at least one receptacle (14), in which at least one edge region (20) of the deformable element (7) is accommodated, is formed by the circumferential surface (13) of the pump housing (2) and at least one counter-holder (15).

Description

technical field [0001] The invention relates to a pump for conveying liquids, which is particularly suitable for conveying exhaust gas purification additives, such as aqueous urea solutions, into exhaust gas purification devices for cleaning the exhaust gases of internal combustion engines. Background technique [0002] Exhaust gas purification devices are widely used, for example in the motor vehicle sector, in which liquid additives are used for exhaust gas purification, wherein in particular nitrogen oxides are also to be separated from the exhaust gas. So-called SCR methods (SCR = Selective Catalytic Reduction, Selective Catalytic Reduction) are carried out in such exhaust gas purification systems. In the SCR method, nitrogen oxides in the exhaust gas are reduced using a reducing agent, usually ammonia. Ammonia is usually not stored directly in the motor vehicle, but in the form of a liquid (exhaust gas) additive that is placed outside the exhaust gas (in an external re...

AI Technical Summary

Problems solved by technology

In addition, it is often problematic to completely empty the pump, since this makes re-admission of the delivery significantly more difficult after a stoppage of operation.

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