Tapered sound outlet vane pump

A vane cell pump comprising:

• an electrical pump unit that has a pump chamber into and out of which a fluid can flow;
• a rotor with a number of vanes, said vanes being arranged to move in the rotor such that the fluid can be compressed before flowing out from the pump chamber;
• a sound-damping mechanism in fluid communication with the pump chamber, said sound-damping mechanism including a sound-damping cover attached to a part of the pump chamber such that a sound-damping volume is defined within the sound-damping cover and above a cover plate therewithin;
• a preliminary sound-damping mechanism including a preliminary sound-damping sleeve at least partially within the sound-damping volume, said preliminary sound-damping mechanism further including at least one preliminary sound-damping outlet from which the fluid can flow;
• the preliminary sound-damping outlet having a cross-sectional profile formed as a shape occurring between two opposing arcuate lines which intersect at two vertices, said cross-sectional profile being located at an entrance to said preliminary sound-damping outlet, said profile tapering only in the direction of fluid outflow.

A vane cell pump comprising:

• an electrical pump unit that has a pump chamber into and out of which a fluid can flow;
• a rotor with a number of vanes, said vanes being arranged to move in the rotor such that the fluid can be compressed before flowing out from the pump chamber;
• a sound-damping mechanism in fluid communication with the pump chamber, said sound-damping mechanism including a sound-damping cover attached to a part of the pump chamber such that a sound-damping volume is defined within the sound-damping cover and above a cover plate therewithin;
• a preliminary sound-damping mechanism including a preliminary sound-damping sleeve at least partially within the sound-damping volume, said preliminary sound-damping mechanism further including at least one preliminary sound-damping outlet from which the fluid can flow;
• the preliminary sound-damping outlet having a cross-sectional profile at an entrance to said preliminary sound-damping outlet, said profile tapering only in the direction of fluid outflow, wherein said cross-sectional profile is formed as a shape occurring between two opposing arcuate lines which intersect at two vertices.