Patent ID: 8915068

Claim:
A device ( 40 ) for reducing pollutants in the exhaust gas stream of an internal combustion engine, the device having a reducing agent ( 46 ) held in a storage tank ( 42 ) and a feed module for injecting the reducing agent ( 46 ) into the exhaust gas stream as well as a pump ( 56 , 100 ) for delivering the reducing agent ( 46 ) from an intake point ( 62 ) in the storage tank ( 42 ) via at least one line ( 58 , 66 ) to the feed module, characterized in that the pump ( 56 , 100 ) is arranged below a reducing agent level ( 44 ) in the storage tank ( 42 ) and a backflow barrier is provided, wherein the backflow barrier is a valve ( 158 ) incorporated into the pump ( 100 ), and wherein the pump ( 100 ) comprises a housing top ( 102 ) with an inlet ( 104 ) and a housing bottom ( 106 ) with an outlet ( 108 ) for the reducing agent ( 46 ), wherein an electromagnet ( 110 ) with a magnetic core ( 112 ) and a cylindrical coil ( 114 ) is incorporated in the housing bottom ( 106 ), which electromagnet is covered with a nonmagnetic isolating disc ( 116 ), and a substantially disc-shaped armature plate ( 118 ) movable along a longitudinal axis ( 120 ) is arranged in the housing top ( 102 ), wherein a peripheral, resilient sealing membrane ( 122 ) is provided between the armature plate ( 118 ) and the isolating disc ( 116 ) to define at least in part a delivery chamber ( 124 ).