GB1559259A

GB1559259A - Centrifugal pump

Info

Publication number: GB1559259A
Application number: GB2233577A
Authority: GB
Original assignee: GOETZ AG
Current assignee: GOETZ AG
Priority date: 1976-05-26
Filing date: 1977-05-26
Publication date: 1980-01-16
Also published as: IT1075437B; DE2623583A1; NL7702603A; DE2623583C2; FR2352971A1

Description

(54) CENTRIWOAL PUMP (71) We, GOETZE AG (formerly known as Goetzewerke-Friedrich Goetze A.G.), a Body Corporate organised and existing under the laws of the Federal Republic of Germany, of Bürgermeister- Schmidt-Strasse 17. 5093 Burscheid, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to an impeller assembly for a centrifugal pump including a face seal for interposition between the impeller and the pump casing.

The centrifugal pumps often used in motor vehicles as cooling-water pumps generally comprise two housing halves, one housing half serving as bearing for a driving shaft projecting into the housing unterior while the other housing half carries the inlet and outlet orifices for the coolingwater piping. Within the pump housing an impeller provided with blades is mounted on the end of the driving shaft, being fixed for rotation with the shaft. For sealing the gap between the rotating driving shaft and the stationary housing half, a face seal is provided, adapted to be pressed into a corresponding recess of the housing, the face seal comprising a sliding ring which bears sealingly under axial spring force against a counter-ring mounted fast for rotation and tight on the driving shaft.The mounting of such cooling-water pumps gives rise to difficulties, since firstly the sliding-ring assembly has to be pressed over the driving shaft into the recess of the pump housing, and then the counter-ring has to be drawn onto the driving shaft. Finally, the impeller is pressed onto the end of the driving shaft.

Whereas the position of the sliding-ring assembly is defined by an axial stop on the housing. the impeller is aligned according to the driving shaft. The position of the counter-ring arranged between the sliding ring assembly and the impeller is, however, completely undefined, so that reliable functioning of the seal is not ensured.

German Offenlegungsschrift 2,405,616 (corresponding to our British Patent Application No. 5140/75, Serial No. 1,486,541) proposes, in order to facilitate assembly, combining the sliding ring and counter-ring to form an assembly unit, so that they can thus be mounted simultaneously. However, the axial position of the counter-ring is still indefinite as before, or it is dependent on the final position of the impeller.

In accordance with the present invention there is provided an impeller assembly for a centrifugal pump comprising an impeller constructed for mounting on the end of a driivng shaft and a face seal for interposition between the impeller and the pump casing, the face seal including a sliding ring and a counter-ring and means for resiliently biassing the sliding ring against the counterring, wherein the impeller and the face seal are combined into a single unit to facilitate installation in the pump.

In a preferred construction the face seal has a housing for mounting in the pump casing, the sliding ring being mounted in the housing, the counter ring is so coupled to the housing that it is free to rotate but restrained against axial movement, and the counter ring is fast with the impeller. The assembly comprising the face seal and the impeller can be pushed in one operation, on to the end of the centrifugal-pump driving shaft, the position of the parts with respect to one another being dependent solely on the position of the impeller on the driving shaft.

It is furthermore proposed to provide the impeller with axial orifices in the region of the external diameter of the seal housing. It is thereby possible, with the aid of a special assembly tool, to press simultaneously and at a definite axial distance apart both the impeller onto the driving shaft and also the sealing housing into the reception bore of the pump housing.

Preferably, the impeller is made in the form of a drawn sheet-metal part, and has a sleeve-like hub, extending axially in a direction towards the sliding-ring seal, for receiving the counter-ring.

Fixing of the counter-ring on the impeller hub is advantageously effected by means of a tight seat with interposition of a rubber ring. For this purpose, it is advantageous if the rubber ring has an inner peripheral surface stepped in the axial direction, the region with the larger internal diameter being fitted on the hub of the impeller, while the region with the smaller internal diameter firmly embraces the driving shaft. The rubber ring thus not only serves as fixing part of the counter-ring on the impeller hub, but at the same time seals this connection as well as the counter-ring relative to the driving shaft in the fitted condition. Pre ferably, the axial ends of the rubber ring have radial projections which come to bear in the region of both end faces of the counter-ring. Axial displacement of the rubber ring during assembly is thereby avoided.

Embodiment examples of the invention are described more particularly in the following and are represented in the drawings, in which: Figures 1 and 2 each show in half-section a cooling-water pump for motor vehicles.

The pump housing consists of the two housing halves 1 and 2. Projecting into the pump housing is a driving shaft 3, on the free end 4 of which is mounted the assembly unit according to the invention and comprising the impeller 5 and a face seal including sliding ring 6 and counter-ring 7.

Whereas the seal housing 8 is pressed fast for rotation and tightly into the reception bore 9 of the pump-housing half 1, the counter-ring 7-with interposition of a rubber ring 10-and the impeller 5 are connected fast for rotation and tightly to the driving shaft 3.

In the embodiment example of Figure 1, the rubber ring 10 has a stepped cross-sectional profile, so that for about half its axial extent, it embraces the hub 11 of the impeller, while with its remaining inner periphery of smaller diameter it lies directly on the surface of the driving shaft 3. For the axial location of the rubber ring 10 with respect to the counter-ring 7, radial projec- tions 12, 13 extend on both sides of the end faces of the counter-ring 7. The impeller 5, which is formed as a drawn sheetmetal part. has axial openings 14, extending in the peripheral direction of the region of the outer diameter of the sealing housing 8, and serving for the introduction of an assembly tool, not shown.

In the embodiment example shown in Figure 2, the impeller 15 has a hub part 17, drawn axially in the direction towards the counter-ring 116 and extending with its radially inner part 18 in the opposite axial direction. The free end 19 then forms an axial stop, while the part 17 serves as seating face for the counter-ring 16. A rubber ring 20 of angular cross-section is located between hub part 17 and counter-ring 16.

WHAT WE CLAIM IS:- 1. An impeller assembly for a centrifugal pump comprising an impeller constructed for mounting on the end of a driving shaft and a face seal for interposition between the impeller and the pump casing, the face seal including a sliding ring and a counter-ring and means for resiliently biassing the sliding ring against the counter ring, wherein the impeller and the face seal are combined into a single unit to facilitate installation in the pump.

2. An impeller assembly as claimed in claim 1 in which the face seal has a housing for mounting in the pump casing, the sliding ring being mounted in the housing, the counter ring is so coupled to the housing that it is free to rotate but restrained against axial movement, and the counter ring is fast with the impeller.

3. An impeller assembly as claimed in claim 1 or 2 in which the impeller has axial orifices in the region of the outer diameter of the seal housing.

4. An impeller assembly as claimed in any of claims 1 to 3 in which the impeller is a drawn sheet metal part with a sleevelike hub extending towards the seal, the counter-ring being fixed on the hub.

5. An impeller assembly as claimed in claim 4 having a rubber -ring interposed between the hub and the counter-ring.

6. An impeller assembly as claimed in claim 5, in which the rubber ring has a stepped internal bore of which the larger diameter part is fitted on the hub and the smaller diameter part is for fitting on the driving shaft.

7. An impeller assembly as claimed in claim 5 or 6 wherein the rubber ring has radial projections at its axial ends.

8. An impeller assembly for a centrifugal pump substantially as described with reference to Fig. 1 or Fig. 2 of the accompanying drawings.

9. A centrifugal pump having an impeller assembly as claimed in any of the preceding claims.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. form of a drawn sheet-metal part, and has a sleeve-like hub, extending axially in a direction towards the sliding-ring seal, for receiving the counter-ring. Fixing of the counter-ring on the impeller hub is advantageously effected by means of a tight seat with interposition of a rubber ring. For this purpose, it is advantageous if the rubber ring has an inner peripheral surface stepped in the axial direction, the region with the larger internal diameter being fitted on the hub of the impeller, while the region with the smaller internal diameter firmly embraces the driving shaft. The rubber ring thus not only serves as fixing part of the counter-ring on the impeller hub, but at the same time seals this connection as well as the counter-ring relative to the driving shaft in the fitted condition. Pre ferably, the axial ends of the rubber ring have radial projections which come to bear in the region of both end faces of the counter-ring. Axial displacement of the rubber ring during assembly is thereby avoided. Embodiment examples of the invention are described more particularly in the following and are represented in the drawings, in which: Figures 1 and 2 each show in half-section a cooling-water pump for motor vehicles. The pump housing consists of the two housing halves 1 and 2. Projecting into the pump housing is a driving shaft 3, on the free end 4 of which is mounted the assembly unit according to the invention and comprising the impeller 5 and a face seal including sliding ring 6 and counter-ring 7. Whereas the seal housing 8 is pressed fast for rotation and tightly into the reception bore 9 of the pump-housing half 1, the counter-ring 7-with interposition of a rubber ring 10-and the impeller 5 are connected fast for rotation and tightly to the driving shaft 3. In the embodiment example of Figure 1, the rubber ring 10 has a stepped cross-sectional profile, so that for about half its axial extent, it embraces the hub 11 of the impeller, while with its remaining inner periphery of smaller diameter it lies directly on the surface of the driving shaft 3. For the axial location of the rubber ring 10 with respect to the counter-ring 7, radial projec- tions 12, 13 extend on both sides of the end faces of the counter-ring 7. The impeller 5, which is formed as a drawn sheetmetal part. has axial openings 14, extending in the peripheral direction of the region of the outer diameter of the sealing housing 8, and serving for the introduction of an assembly tool, not shown. In the embodiment example shown in Figure 2, the impeller 15 has a hub part 17, drawn axially in the direction towards the counter-ring 116 and extending with its radially inner part 18 in the opposite axial direction. The free end 19 then forms an axial stop, while the part 17 serves as seating face for the counter-ring 16. A rubber ring 20 of angular cross-section is located between hub part 17 and counter-ring 16. WHAT WE CLAIM IS:-

1. An impeller assembly for a centrifugal pump comprising an impeller constructed for mounting on the end of a driving shaft and a face seal for interposition between the impeller and the pump casing, the face seal including a sliding ring and a counter-ring and means for resiliently biassing the sliding ring against the counter ring, wherein the impeller and the face seal are combined into a single unit to facilitate installation in the pump.