Pump and fuel cell system having a pump
View Patent ↗A pump has a shaft, an impeller arranged on the shaft, and a labyrinth seal which is arranged between stationary and moving parts of the pump. A plurality of blades are arranged on the rotor and a labyrinth seal extends at least between the shaft and a rear portion of the blades. A gap in the labyrinth seal is designed such that liquid water can be actively carried away, with the labyrinth seal for this purpose being designed at least in places with a channel in the form of a spiral and/or a staircase. The invention also relates to a fuel cell system having such a pump.
1. A pump comprising:
a shaft;
an impeller arranged on the shaft; and
a labyrinth seal arranged between stationary and moving parts of the pump; wherein,
a plurality of blades are arranged on the impeller;
the labyrinth seal extends at least between the shaft and a rear portion of the blades;
the labyrinth seal has at least one channel which extends in a helical shape; and
at least portions of a surface of the impeller which faces the labyrinth seal is structured with a roughness which is greater than that on a further surface of the impeller.
2. The pump as claimed in claim 1 , wherein the at least one channel is formed on a casing side of the labyrinth seal.
3. The pump as claimed in claim 2 , wherein the at least one channel is formed circumferentially around an axis of the shaft, at substantially the same radius.
4. The pump as claimed in claim 1 , wherein:
relative to considered its longitudinal direction, the at least one channel is open at a side, in a casing side of the labyrinth seal; and
in an installed state, in which the labyrinth seal has been inserted into the pump, the rear portions of the blades form a channel wall.
5. The pump as claimed in claim 1 , wherein the at least one channel comprises at least two revolutions.
6. The pump as claimed in claim 1 , wherein areas of the labyrinth seal which face the rear portion of the blades are tapered to a point.
7. The pump as claimed in claim 1 , wherein areas of the labyrinth seal which face the rear portion of the blades are flat.
8. The pump as claimed in claim 1 , wherein the at least portions of the surface of the impeller which faces the labyrinth seal are coated with a metal layer that has greater roughness than the further surface of the impeller.
9. A pump comprising:
a shaft;
an impeller arranged on the shaft; and
a labyrinth seal arranged between stationary and moving parts of the pump; wherein,
a plurality of blades are arranged on the impeller;
the labyrinth seal extends at least between the shaft and a rear portion of the blades;
the labyrinth seal has at least one channel which extends in a helical shape; and
at least portions of a side of the labyrinth seal which faces the impeller is structured with a greater roughness than a further surface of the labyrinth seal.
10. A pump comprising:
a shaft;
an impeller arranged on the shaft; and
a labyrinth seal arranged between stationary and moving parts of the pump; wherein,
a plurality of blades are arranged on the impeller;
the labyrinth seal extends at least between the shaft and a rear portion of the blades;
the labyrinth seal has at least one channel which extends in a helical shape; and
at least a portion of a surface of the labyrinth seal is coated with a hydrophobic material.
11. The pump as claimed in claim 1 , wherein the impeller tapers in a direction of the rear portion of the blades.
12. The pump as claimed in claim 1 , wherein a junction between the surface of the impeller and rear portion of the blades is formed without corners.
13. The pump as claimed in claim 1 , wherein the pump comprises a side-channel compressor.
14. A fuel cell system having at least one fuel cell and one pump as claimed in claim 1 .
15. The fuel cell system as claimed in claim 14 , wherein the pump is associated with an anode branch of the fuel cell.