| 摘要 |
<p>The invention relates to a pumping device (20) for supplying an exhaust gas aftertreament system (10) of an internal combustion engine with a reductant (14), in particular with a urea-water solution, in order to reduce nitrogen oxides (NOx) in the exhaust gas flow of the internal combustion engine, comprising a motor (32) for driving two pumps (22, 24). According to the invention, the first pump (22) is connected to the motor (32) by means of a first coupling, and the second pump (24) is connected to the motor by means of a second coupling. In a preferred embodiment, the couplings are designed as freewheel couplings (26, 28) acting in opposite directions, so that a switch between a "pumping state" and a "suck-back state" can be made by simply reversing the direction of rotation of the motor (32).</p> |
