GB2187515A

GB2187515A - Rotary pump

Info

Publication number: GB2187515A
Application number: GB08605581A
Authority: GB
Inventors: Zag Bishrey
Original assignee: Perkins Engines Group Ltd
Current assignee: Perkins Engines Group Ltd
Priority date: 1986-03-06
Filing date: 1986-03-06
Publication date: 1987-09-09
Also published as: GB8605581D0

Abstract

A rotary pump comprises a housing and a rotary impeller (3) that is mounted within the housing to pump coolant radially outwards into a surrounding annular gallery in the housing, the impeller comprising a disc (12) with a series of vanes (13) on one face that extend radially of the disc and one or more of which terminate short of the outer periphery of the disc. Thus, the outer periphery of the disc (12) may be located closely adjacent the throat of the surrounding gallery, but the outer periphery of the vanes (13) are spaced away from the throat to produce a reduced flow rate as compared with an impeller having vanes that extend fully to the periphery of the disc. <IMAGE>

Description

SPECIFICATION Rotary pump Technical field This invention relates to a rotary pump of the type used to circulate coolant in an internal combustion engine.

Known engine coolant pumps comprise a rotary impeller that is mounted within a housing and serves to a pump coolant radially outwards. The impeller comprises a disc with a series of vanes on one face that extend radially of the disc to its outer periphery, and the housing has a chamber in which the impeller is mounted so that the radially extending free edges of the vanes are spaced closely adjacent a rear wall of the chamber and pump coolant from an inner coolant inlet to an outer annular gallery surrounding the impeller. A restricted throat connects the gallery to the chamber, and the outer periphery of the disc and vanes are spaced closely adjacent the edges of said throat to ensure maximum transfer of coolant and minimum leakage or recirculation. The gallery is of involute form and feeds the pumped coolant to an outlet.

These known rotary coolant pumps are designed to deliver coolant at a specific rate for a given speed of rotation. Thus, if different feed rates are required, then different size pumps have been provided.

Disclosure of the invention According to the present invention, a rotary pump comprises a housing and a rotary impeller that is mounted within the housing to pump coolant radially outwards into a surrounding annular gallery in the housing, the impeller comprising a disc with a series of vanes on one face that extends radially of the disc and one or more of which terminate short of the outer periphery of the disc. Thus, the outer periphery of the disc may be located closely adjacent the throat of the surrounding gallery, but the outer periphery of the shorter vanes are spaced away from the throat to produce a reduced flow rate as compared with an impeller having vanes that all extend fully to the periphery of the disc.The same pump housing can therefore be used with either a conventional impeller or one according to the invention having shorter vanes, to allow manufacture of pumps with different flow rates.

Description of the drawings The invention will now be described by way of example with reference to the accompanying drawings in which Figure 1 is an axial cross-section through a pump according to the invention, and Figure 2 is a general outline of the pump and rear face of the impeller of Fig. 1 Best mode of carrying out the invention The illustrated pump comprises a housing 1 formed with a chamber 2 to receive an impeller 3. The impeller 3 is mounted on a shaft 4 supported in bearings 5 in the housing 1 and is inserted into the chamber through an opening 6 in the housing, which is then covered by a cover plate 7.

The chamber 2 has a cylindrical side wall 8 centred on the axis of the impeller shaft 4, and a frusto-conical rear wall 9 that is inclined inwards away from the cover plate 7 and terminates in a central inlet 10 that communicates with two coolant inlet ducts 11 formed integraliy in the housing 1. The impeller 3 comprises a disc 12 formed with arcuate, radially extending vanes 13 on its rear face 14, and is adapted so that the periphery of the disc 12 is located closely adjacent the side wall 8 of the chamber and the radially extending edges of the vanes 13 are located closely adjacent the rear wall 9 of the chamber.

A gear drive including a gearwheel 15 on shaft 4 serves to drive the impeller causing it to pump coolant radially outwards from the inlet 10 through the channel formed between the disc 12 and frusto-conical rear wall 9. An annular gallery 16 is formed in the housing 1 around the chamber 2, and communicates through a restricted opening or throat 17 with the chamber 2 at the angle between the cylindrical side wall 8 and rear wall 9 so as to receive the coolant pumped outwards by the impeller 3. This gallery 16 is of involute form and serves to direct the coolant circumferentially to a coolant outlet duct 18.

The vanes 13 of the impeller 3 terminate short of the periphery of the disc 12 and thereby reduce the coolant pumping rate of the impeller as compared with a similar impeller having vanes 13 that extend fully to the periphery of the disc 12 in the conventional manner. Thus the impeller can be adapted to give any required pumping rate below a maximum level by selecting the radial distance by which the vanes extend outwards on the rear face of the impeller disc 12.

In an alternative embodiment of the invention, not all of the vanes 13 may terminate short of the outer periphery of the disc 12.

For example, alternate vanes 13 may extend radially fully to the outer periphery of the disc 12. In this manner an impeller is produced giving an intermediate flow rate compared with impellers having all full length vanes and all short vanes. Preferably, the arrangement of short and full length vanes is selected to preserve rotary balancing of the impeller.

1. A rotary pump comprising a housing and a rotary impeller that is mounted within the housing to pump coolant radially outwards into a surrounding annular gallery in the housing, the impeller comprising a disc with a

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

Claims

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

SPECIFICATION Rotary pump Technical field This invention relates to a rotary pump of the type used to circulate coolant in an internal combustion engine.

Known engine coolant pumps comprise a rotary impeller that is mounted within a housing and serves to a pump coolant radially outwards. The impeller comprises a disc with a series of vanes on one face that extend radially of the disc to its outer periphery, and the housing has a chamber in which the impeller is mounted so that the radially extending free edges of the vanes are spaced closely adjacent a rear wall of the chamber and pump coolant from an inner coolant inlet to an outer annular gallery surrounding the impeller. A restricted throat connects the gallery to the chamber, and the outer periphery of the disc and vanes are spaced closely adjacent the edges of said throat to ensure maximum transfer of coolant and minimum leakage or recirculation. The gallery is of involute form and feeds the pumped coolant to an outlet.

These known rotary coolant pumps are designed to deliver coolant at a specific rate for a given speed of rotation. Thus, if different feed rates are required, then different size pumps have been provided.

Disclosure of the invention According to the present invention, a rotary pump comprises a housing and a rotary impeller that is mounted within the housing to pump coolant radially outwards into a surrounding annular gallery in the housing, the impeller comprising a disc with a series of vanes on one face that extends radially of the disc and one or more of which terminate short of the outer periphery of the disc. Thus, the outer periphery of the disc may be located closely adjacent the throat of the surrounding gallery, but the outer periphery of the shorter vanes are spaced away from the throat to produce a reduced flow rate as compared with an impeller having vanes that all extend fully to the periphery of the disc.The same pump housing can therefore be used with either a conventional impeller or one according to the invention having shorter vanes, to allow manufacture of pumps with different flow rates.

Description of the drawings The invention will now be described by way of example with reference to the accompanying drawings in which Figure 1 is an axial cross-section through a pump according to the invention, and Figure 2 is a general outline of the pump and rear face of the impeller of Fig. 1 Best mode of carrying out the invention The illustrated pump comprises a housing 1 formed with a chamber 2 to receive an impeller 3. The impeller 3 is mounted on a shaft 4 supported in bearings 5 in the housing 1 and is inserted into the chamber through an opening 6 in the housing, which is then covered by a cover plate 7.

The chamber 2 has a cylindrical side wall 8 centred on the axis of the impeller shaft 4, and a frusto-conical rear wall 9 that is inclined inwards away from the cover plate 7 and terminates in a central inlet 10 that communicates with two coolant inlet ducts 11 formed integraliy in the housing 1. The impeller 3 comprises a disc 12 formed with arcuate, radially extending vanes 13 on its rear face 14, and is adapted so that the periphery of the disc 12 is located closely adjacent the side wall 8 of the chamber and the radially extending edges of the vanes 13 are located closely adjacent the rear wall 9 of the chamber.

A gear drive including a gearwheel 15 on shaft 4 serves to drive the impeller causing it to pump coolant radially outwards from the inlet 10 through the channel formed between the disc 12 and frusto-conical rear wall 9. An annular gallery 16 is formed in the housing 1 around the chamber 2, and communicates through a restricted opening or throat 17 with the chamber 2 at the angle between the cylindrical side wall 8 and rear wall 9 so as to receive the coolant pumped outwards by the impeller 3. This gallery 16 is of involute form and serves to direct the coolant circumferentially to a coolant outlet duct 18.

The vanes 13 of the impeller 3 terminate short of the periphery of the disc 12 and thereby reduce the coolant pumping rate of the impeller as compared with a similar impeller having vanes 13 that extend fully to the periphery of the disc 12 in the conventional manner. Thus the impeller can be adapted to give any required pumping rate below a maximum level by selecting the radial distance by which the vanes extend outwards on the rear face of the impeller disc 12.

In an alternative embodiment of the invention, not all of the vanes 13 may terminate short of the outer periphery of the disc 12.

For example, alternate vanes 13 may extend radially fully to the outer periphery of the disc

12. In this manner an impeller is produced giving an intermediate flow rate compared with impellers having all full length vanes and all short vanes. Preferably, the arrangement of short and full length vanes is selected to preserve rotary balancing of the impeller.

1. A rotary pump comprising a housing and a rotary impeller that is mounted within the housing to pump coolant radially outwards into a surrounding annular gallery in the housing, the impeller comprising a disc with a series of vanes on one face that extend radially of the disc and one or more of which terminate short of the outer periphery of the disc.

2. A pump as claimed in claim 1 in which the impeller is located in a chamber with a cylindrical side wall so that the periphery of the disc is located closely adjacent said side wall.

3. A pump as claimed in claim 2 in which said gallery has a restricted opening through which it communicates with said chamber, and in which said one or more shorter vanes terminate short of said opening.

4. A pump as claimed in claim 2 or 3 in which the chamber has an opening through which the impeller is inserted and which is closed by a cover, and in which the radially extending edges of the vanes are located closely adjacent a rear wall of the chamber.

5. A pump as claimed in any one of the preceding claims in which all of the vanes terminate short of the outer periphery of the disc.

6. A pump as claimed in any one of claims 1 to 4 in which the vanes around the disc alternately terminate short of the outer periphery of the disc and extend fully radially to the outer periphery of the disc.

7. A rotary pump substantially as herein described with reference to the accompanying drawings.

CLAIMS Amendments to the claims have been filed, and have the following effect: Claim 3 above has been deleted.

New or textually amended claims have been filed as follows:

1. A rotary pump comprising a housing and a rotary impeller that is mounted within a chamber in the housing to pump coolant radially outwards from the chamber into a surrounding annular gallery in the housing that communicates with the chamber through a restricted opening, the impeller comprising a disc with a series of vanes on one or more of which terminate short of the outer periphery of the disc and short of said restricted opening.

Claims 4 to 7 above have been re-numbered as claims 3 to 6 and their appendancies corrected.