DE2236082A1 - CENTRIFUGAL PUMP - Google Patents

Description

PATENT LAWYERS Dipping. WERTER COHAUSZ. Dipl-lng. WILHELM FLORACK. Dipl-lng. RUDOLF KNAUF

/ - -4 Düsseldorf, Schümannstrasse 97

Joseph Lucas (Industries) Limited July 21, 1972 Great King Street
Birmingham / England

centrifugal pump

The invention relates to a centrifugal pump with an in a first chamber running first impeller, the liquid from an inlet opening into the chamber to one of the chamber outgoing outlet promotes and is driven via a shaft by an electric motor, which is in a second Chamber is arranged.

The object of the invention is to create a centrifugal pump that is as simple and reliable as possible.

This object is achieved in that between the first chamber and the second chamber a third chamber is arranged separated from these by seals, in which a driven by the electric motor second impeller the liquid leaking from the first and second chambers into the third chamber through the seals promotes to the outlet of the third chamber.

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It is preferably proposed that the seal arranged between the second and the third chamber is a labyrinth seal through which the second impeller causes a substantially constant flow of air, to act on the liquid passing through the labyrinth seal.

A sealed ball bearing can support the motor shaft near the labyrinth seal and next to the ball bearings at least one passage through which air flows past the ball bearing to the labyrinth seal, so that there is no pressure drop across the ball bearing.

An embodiment of the invention is shown in the drawing in a longitudinal section and is described below described in more detail.

The centrifugal pump has a housing 10 with an inlet 11 at the end of the housing. The pump stands on supports 12, which extend from the housing near the inlet 11 so that the pump is perpendicular to the bottom 13 of a fuel tank can be asked. Within the housing 10, a block 14 is sealed, which is part of a Spiral or helical chamber 15 limited. the Chamber 15 is connected to an outlet 16 introduced in the housing 10.

A plate 17 is fastened in a sealed manner on the block 14, which delimits a chamber 18 in the housing 10. Between the plate 17 and the block 14 there is a chamber 19 »

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which are connected to an annular space 20 arranged in block 14 stands. The annulus 20 communicates with a second outlet 21 of the housing. Inside the chamber 18 there is an electric motor 22 whose shaft 23 runs through a sealed ball bearing 24 provided with permanent lubrication, which extends from the plate 17 will be carried. The shaft 23 also runs one after the other by a labyrinth seal arranged in the plate 17. 25, through the chamber 19 and through a shaft seal 31 in block 14, which separates the chamber 19 from the Xammer 15.

Around the motor 22 is located in the housing 10 Intermediate space 26, which is via a channel 27 with the atmosphere is in connection. Through the channel 27, supply cables for the motor 22 are also laid. On the shaft 23 An impeller 28 is in the chamber 15 and an impeller in the chamber 19 an impeller 29 attached. A passage 30 connects the chamber 18 to the side of the ball bearing facing away from the motor 24.-

The impeller 28 promotes fuel in a known manner Inlet to outlet 16. Air flowing from chamber 18 into the Chamber 19 through passage 30 and through labyrinth 25 leaks, is conveyed by the impeller 29 to the outlet 21, which is connected to a drain. The one through the shaft seal Fuel leaking into chamber 19 is also conveyed out through inlet 21. The essentially constant air flow through the labyrinth seal 25 into the chamber 19 ensures. That no fuel or ' Fuel vapor reaches the ball bearing 24 or the chamber 18.

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Any fuel vapor that might be in the chamber 18 is thus sucked off through the passage 30 and the labyrinth 25 and carried out through the outlet 21. The ball bearing 24 is thus exposed to the fuel vapor for only a minimal duration, since the fuel vapor bypasses the ball bearing through the passage 30 in a manner similar to a bypass. The lubricant in the ball bearing 24 is therefore not exposed to the fuel vapor and is therefore not impaired by the fuel vapor.

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Claims (3)

Expectations . 1. ) Centrifugal pump with a first impeller running in a first chamber, which conveys liquid from an inlet opening into the chamber to an outlet going out of the chamber and is driven via a shaft by an electric motor which is arranged in a second chamber., characterized _s that a third chamber (19) of which is arranged separated by seals ₅ in a driven by the electric motor (22) second impeller (29), the first of the between the first chamber (I5) and the second chamber (l8) and the second chamber (15, 18) into the third chamber (19) conveys liquid leaking through the seals (25, 31) to the outlet (21) of the third chamber. 2. Centrifugal pump according to claim l _s characterized in that the seal arranged between the second and the third chamber is a labyrinth seal (25) through which the second impeller (29) causes a substantially constant air flow to flow through the Labyrinth seal (25) to act through liquid. 3. Centrifugal pump according to claim 2 _ß characterized in that a sealed ball bearing (24) carries the motor shaft (23) in the vicinity of the labyrinth seal '(25), and next to the ball bearings (24) at least one passage (j50) is arranged through flowing the air at the ball bearing by the labyrinth seal (25) _s so that no pressure drop occurs across the ball bearings (24). 26 284
HC / Be 209885/1045 BATHROOM ORIGlNAt L e r s e i t e