WO2008071592A1

WO2008071592A1 - Hydraulic pump

Info

Publication number: WO2008071592A1
Application number: PCT/EP2007/063242
Authority: WO
Inventors: Francesco Sinico; Anders Lykkegaard Moller
Original assignee: Dab Pumps S.P.A.
Priority date: 2006-12-14
Filing date: 2007-12-04
Publication date: 2008-06-19
Also published as: EP2092198A1

Abstract

A hydraulic pump (10), of the type which comprises a jacket (11) for containing an impeller assembly (12), which is closed at its ends respectively by a closure head (13) and by a pump body (14) for connection to the hydraulic system. The pump body (14) comprises a footing (17) from which two mutually opposite flanges (18a, 18b) for fixing the pump to the hydraulic system protrude monolithically with respect to the footing ( 17). A box-like body (21 ) is arranged on the footing (17) and forms internally two mutually isolated chambers (22, 23) which are open upward, respectively a first chamber (22) for sending fluid into the impeller assembly (12) and a second chamber (23) for collecting the fluid that arrives from the impeller assembly ( 12). The pump body ( 14) further comprises two sleeves (29, 30), a first intake sleeve (29), which protrudes from the first chamber (22) and is associated at one end with a first one (18a) of the flanges, and a second delivery sleeve (30), which protrudes from the second chamber (23) and is associated at one end with the second ( 18b) of the flanges. The space formed by the contour of the footing (17) which is comprised between the jacket ( 11) and the flanges (18a, 18b) and is occupied by the sleeves (29, 30) is open upward.

Description

HYDRAULIC PUMP

The present invention relates to a hydraulic pump particularly but not exclusively of the multistage vertical type.

It is known that hydraulic pumps for hydraulic systems of users of various sizes are generally constituted by an outer casing made of steel, in which the water intake and delivery ports and the chamber of the impeller assembly (with one or more impellers, depending on the number of stages) are formed, an electric motor being connected thereto and being arranged inside or outside the casing.

Generally speaking, the casing of a hydraulic pump of the vertical type is constituted usually by a jacket for containing the impeller assembly, which is closed at its ends respectively by a closure head and by a pump body for connection to the hydraulic system.

An intake port and a delivery port are formed in the connecting pump body and are functionally connected respectively to the intake and the delivery of the impeller assembly.

Among the various characteristics of a pump, it is important to stress the resistance of the various components to corrosion caused by water.

Further, the jacket, the closure head and the pump body must be made of a material which has structural strength characteristics, since they must bear a certain load.

The material which has both load strength and corrosion resistance characteristics is stainless steel.

Among the cited pump components, the pump body is one of the most critical in terms of cost.

The pump body in fact has a complex internal geometry and must be worked so as to ensure, in certain parts thereof, a finish which allows correct matings with other components in order to avoid inaccurate hydraulic connections and consequent leaks.

Further, the pump body is also one of the heaviest components, since it also acts as a footing for the pump.

In order to try to reduce production costs, many types of pump have a pump body made of cast iron, which is generally much cheaper than stainless steel.

It goes without saying that cast iron corrosion is certainly much swifter than any corrosion of an average-quality stainless steel, and for this reason said pumps must be replaced after a certain time. In order to extend the life of the pumps with a cast-iron pump body, corrosion-proofing treatments are performed on said pump body, increasing the overall costs of the finished pump and in any case failing to ensure a performance, in terms of duration, equal to what can be achieved with stainless steel pump bodies. Disclosure of the Invention

The aim of the present invention is to provide a hydraulic pump which solves the problems noted in known types.

Within this aim, an object of the present invention is to provide a hydraulic pump which has a reduced use of stainless steel with respect to known types while ensuring a performance, in anticorrosion terms, comparable to known types.

Another object of the present invention is to provide a hydraulic pump which has lower costs than known types for equal anticorrosion performance. Another object of the present invention is to provide a hydraulic pump which reduces the number of processes to be performed on the pump body.

Another object of the present, invention is to provide a hydraulic pump which can be manufactured with known systems and technologies. This aim and these and other objects, which will become better apparent hereinafter, are achieved by a hydraulic pump, of the type which comprises a jacket for containing the impeller assembly, which is closed at its ends respectively by a closure head and by a pump body for connection to the hydraulic system, characterized in that said pump body comprises a footing from which two mutually opposite flanges for fixing the pump to the hydraulic system protrude monolithically with respect to said footing, a box- like body being arranged on said footing and forming internally two mutually isolated chambers which are open upward, respectively a first chamber for sending fluid into the impeller assembly and a second chamber for collecting the fluid that arrives from said impeller assembly, said pump body comprising two sleeves, a first intake sleeve, which protrudes from said first chamber and is associated at one end with a first one of said flanges, and a second delivery sleeve, which protrudes from said second chamber and is associated at one end with the second of said flanges, the space formed by the contour of said footing which is comprised between said jacket and said flanges and is occupied by said sleeves being open upward. Brief description of the Drawings

Further characteristics and advantages of the invention will become better apparent from the following detailed description of two preferred but not exclusive embodiments thereof, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of a pump according to the invention; Figure 2 is an exploded perspective view of the lower part of the pump of Figure 1 in a first embodiment thereof;

Figure 3 is a sectional side view of the lower part of the pump of Figure 2,

Figure 4 is a sectional side view of the lower part of the pump according to the invention in a second embodiment thereof. With reference to the figures, a hydraulic pump according to the invention is generally designated by the reference numeral 10.

The hydraulic pump 10 comprises a jacket 1 1 for containing an impeller assembly 12, shown schematically in broken lines in Figure 3; in this embodiment, the pump is of the multistage vertical type and the impeller assembly corresponds to a multistage impeller.

The jacket 1 1, which has a cylindrical contour, is closed at its ends respectively by a closure head 13 and by a pump body 14 for connection to the hydraulic system, as clearly visible in Figure 2.

The closure head 13 and the connecting pump body 14 are connected by tension elements 15 in a per se known manner.

An electric motor 16 is fixed externally on the closure head 13 and its output shaft passes through the head 13 in order to connect to the impeller assembly 12 inside the jacket 1 1.

According to the invention, the connecting pump body 14 comprises a footing 17 from which two mutually opposite flanges 18a and 18b for fixing the pump 10 to the hydraulic system protrude monolithically with respect to said footing. In particular, the flanges 18a and 18b are constituted by mutually opposite circular portions which are perpendicular to the footing 17; the flanges 18a and 18b are strengthened by respective pairs of lateral wings 19 which protrude on the sides of the footing to a perimetric portion of said flanges, thus delimiting a central compartment 20 which is open upward. In the compartment 20, on the footing, there is a box-like body 21 which forms internally two mutually isolated chambers which are open upward, respectively a first chamber 22 for sending fluid into the impeller assembly 12 and a second chamber 23 for collecting the fluid that arrives from the impeller assembly 12. In particular, in this first embodiment, the box-like body 21 is constituted by a first cup-shaped body 24, which is open upward and is provided laterally, on opposite sides, with a first hole 25 and a second hole 26, and a second cup-shaped body 27 which is arranged so that it is open upward on the closed bottom of the first cup-shaped body 24 and is provided laterally with a third hole 28 which is aligned with the first hole 25; both have a predominantly cylindrical contour.

The space between the side walls of the first cup-shaped body 24 and of the second cup-shaped body 27 forms the second chamber 23, while the space inside the second cup-shaped body 27 forms the first chamber 22. The pump body 14 comprises two sleeves 29 and 30, which constitute the intake port and the delivery port of the pump.

In particular, a first one 29 of the sleeves, related to the intake of the pump, is arranged through the first hole 25 of the first cup-shaped body 24 and is connected at its end to the third hole 28 of the second cup-shaped body 27; the end of the first sleeve which lies outside the first chamber 22 is associated with a first one 18a of the flanges.

Likewise, the second sleeve 30 is connected at one end to the second hole 25, while the opposite end, which lies outside the second chamber 22, is associated at one end with the second flange 18b. The jacket 1 1, in this first embodiment, surrounds the first cup-shaped body 24 (and therefore the entire box-like body), which is inserted therein.

In practice, the jacket 1 1 act as a structural containment for the first cup-shaped body 24.

Therefore, two aligned holes 31 are provided in the jacket 1 1 in order to allow the exit of the sleeves 29 and 30 from the chambers 22 and 23 to the flanges 18.

An annular slot 32 for a gasket 33 for providing a seal on the jacket 1 1 is provided on the outside of the wall of the first cup-shaped body 24 and is open outward. The space formed by the contour of the footing 17 comprised between the jacket 1 1 and the flanges 18 and occupied by the sleeves 29 and 30 is open upward; in practice, the sleeves 29 and 30 are visible from the top during use of the pump.

This structural aspect of the footing 17 is very important, since it greatly simplifies its geometry, in practice leading to vertical undercuts which are formed only at the central holes 34 of the flanges 18 and at the bolting holes 35 and to consequent low production costs.

Respective seats 36 for additional gaskets 37 for forming a seal on the outer surface of the respective sleeves 29 and 30 are provided on the internal walls of the first hole 25, of the second hole 26 and of the third hole 28.

As regards the first and second holes 25 and 26, each seat 36 is delimited laterally by a shoulder 38 and by a ring 39 for locking the additional gasket 37 against the shoulder 38. The sleeves 29 or 30 are formed by a cylindrical tubular portion 42, which is inserted in the respective holes 25, 26 and 28 for accessing the chambers 22 and 23 and in the respective central holes 34 of the flanges 18.

In particular, each sleeve, at. the end associated with the respective flange 18, has a wider portion 43, whose diameter is larger than the diameter of the cylindrical tubular portion 42 which forms an annular abutment in contact with the flange.

The "modular" structure of the pump body 14 allows to optimize the use of materials.

The materials are chosen so as to allow the box-like body 21 to withstand corrosion.

The material of which the first cup-shaped body 24 and the second body 27 are made is preferably plastic material and/or stainless steel.

The sleeves 29 and 30 are preferably made of stainless steel.

The footing 17 is preferably made of cast iron. The choice of these materials allows to optimize the performance of the pump while limiting costs.

In a second embodiment thereof, shown in cross-section in Figure 4 and designated therein by the reference numeral 1 10, the box-like body 121 is again constituted by a first cup-shaped body 124, which is provided laterally, on mutually opposite sides, with a first hole 125 and a second hole 126, and a second cup-shaped body 127, which is arranged inside the first body 124 and is provided laterally with a third hole 128 which is aligned with the first hole 125; both cup-shaped bodies 124 and 127 have a predominantly cylindrical contour. The particularity of the second embodiment 1 10 of the invention is that the second cup-shaped body 127 protrudes from the bottom 144 of the first cup-shaped body 124 and is monolithic therewith.

The first sleeve 129 is arranged so as to pass through a first central hole of a first flange 1 18a until it enters the first hole 125, while the second sleeve 130 is arranged so as to pass through a second central hole of the second flange 1 18b until it enters the second hole 126.

The first hole 125 of the first cup-shaped body 124 and the third hole 128 of the second cup-shaped portion 127 are connected by a tubular portion 145, which is also monolithic with the first cup-shaped body 124 and the second cup-shaped body 127.

The first cup-shaped body 124 and the second cup-shaped body 127 which protrudes from it monolithically are substantially concentric.

In this second embodiment of the invention also, the space formed by the contour of the footing 1 17 comprised between the box-like body 121 and the flanges 1 18a and 1 18b, crossed by the sleeves 129 and 130, is open upward.

The lower edge I l i a of the jacket 1 1 1 is fixed so as to rest on a corresponding shoulder 146 which is formed on the facing upper part of the first cup-shaped body 124. An annular slot 132 for a gasket 133 for providing a seal on the jacket 1 1 1 is provided on the outside of the wall of the first cup-shaped body 124, at the shoulder 146 for supporting and fixing the lower edge I l i a of the jacket 1 1 1 , and is open outward.

The second cup-shaped body 127 is surmounted by an annular element 147 for supporting the assembly 1 12.

Respective seats 136 for additional gaskets 137 for forming a seal on the outer surface of the respective sleeves 129 and 130 are provided on the inside walls of the first hole 125 and of the second hole 126.

The box-like body 121 is made of corrosion-resistant material. In particular, the box-like body 121 is made of plastic material or stainless steel or other similar and equivalent material.

In practice it has been found that the invention thus described solves the problems noted in known types of hydraulic pump; in particular, the present invention provides a hydraulic pump which allows to have "anticoiTOsion" performance of high quality even with a limited use of stainless steel.

It is in fact possible to provide the footing 1 7 by using cast iron, which ensures stability to the pump, according to a geometry of limited complexity (in particular, extremely limited undercut volumes), and to provide the box-like body 21 separately by means of cheaper production methods.

The box-like body 21 is made of a corrosion-resistant material, such as for example plastic material or stainless steel (but other materials with corrosion resistance properties can be used). The simple geometry of the components of the box-like body makes their overall production inexpensive.

Advantageously, the intake and delivery ports of the pump are constituted by the sleeves 29 and 30, which are preferably made of stainless steel and have a simple geometry and in which the annular abutment can therefore be manufactured cheaply with a surface finish which ensures correct mating with the pipes to which the pump is to be connected.

In this manner, the manufacturing costs of the pump are reduced both by using less expensive materials and by eliminating finishing work, ensuring high-quality anticorrosion characteristics. Further, at the same time, the overall weights of the pump are reduced due to the introduction of plastic parts which replace stainless steel or cast iron parts.

Moreover, such a structure of the pump allows to choose the materials (stainless steel, cast iron, plastics and others) which are more suitable for the type of liquid to be pumped and for the particular operating requirements, thus increasing design flexibility.

A very important aspect which arises from the particular modular structure of the pump is that the designer can compose the pump by choosing the components according to the need for corrosion resistance, structural strength and low cost performance.

It is also possible to use components which have a corrosion resistance of the traditional type but can be manufactured cheaply, since they can be replaced easily, in view of the modularity of the structure of the pump, once their life cycle has ended. The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent elements.

In practice, the materials employed, so long as they are compatible with the specific use, as well as the dimensions, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Applications No. PD2006A000449 and No. PD2007A000295 from which this application claims priority are incorporated herein by reference. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A hydraulic pump (10), of the type which comprises a jacket (1 1 ) for containing the impeller assembly (12), which is closed at its ends respectively by a closure head (13) and by a pump body (14) for connection to the hydraulic system, characterized in that said pump body (14) comprises a footing (17) from which two mutually opposite flanges ( 18a, 18b) for fixing the pump to the hydraulic system protrude monolithically with respect to said footing ( 17), a box-like body (21) being arranged on said footing (17) and forming internally two mutually isolated chambers (22, 23) which are open upward, respectively a first chamber (22) for sending fluid into the impeller assembly (12) and a second chamber (23) for collecting the fluid that arrives from said impeller assembly (12), said pump body ( 14) comprising two sleeves (29, 30), a first intake sleeve (29), which protrudes from said first chamber (22) and is associated at one end with a first one (18a) of said flanges, and a second delivery sleeve (30), which protrudes from said second chamber (23) and is associated at one end with the second (18b) of said flanges, the space formed by the contour of said footing (17) which is comprised between said jacket (1 1) and said flanges (18a, 18b) and is occupied by said sleeves (29, 30) being open upward.

2. The hydraulic pump according to the preceding claim, characterized in that said box-like body (21) is constituted by a first cup- shaped body (24), which is open upward and is provided laterally, on mutually opposite sides, with a first hole (25) and a second hole (26), and a second cup-shaped body (27) which is arranged, so as to be open upward, on the closed bottom of said first body (24), which is provided laterally with a third hole (28) which is aligned with said first hole (25), the space between the side walls of said first cup-shaped body (24) and said second cup-shaped body (27) forming said second chamber (23), the space inside said second cup-shaped body (27) forming said first chamber (22), said first sleeve (29) being arranged through said first hole (25) and being connected at its end to said third hole (28), said second sleeve (30) being connected at the end to said second hole (26).

3. The hydraulic pump according to the preceding claim, characterized in that said jacket (1 1) surrounds said box-like body (21 ), said sleeves (29, 30) protruding from said jacket (1 1 ) from mutually opposite holes (31 ).

4. The hydraulic pump according to claim 3 or 4, characterized in that an annular slot (32) for a gasket (33) for forming a seal on said jacket (1 1) is provided on the outside of the wall of said first cup-shaped body (24) and is open outward.

5. The hydraulic pump according to one or more of the preceding claims, characterized in that on the inside walls of said first hole (25), of said second hole (26) and of said third hole (28) there are respective seats (36) for additional gaskets (37) for forming a seal on the outer surface of said respective sleeves (29, 30).

6. The hydraulic pump according to the preceding claim, characterized in that said seats (36) related to said first hole (25) and said second hole (26) are delimited laterally by a shoulder (38) and by a ring (39) for locking said additional gasket (37) against said shoulder (38).

7. The hydraulic pump according to one or more of the preceding claims, characterized in that said flanges (18a, 18b) are constituted by mutually opposite circular portions which are perpendicular to the footing (17), said flanges ( 18a, 18b) being strengthened by respective pairs of lateral wings (19) which protrude on the sides of said footing (17) to a perimetric portion of said flanges ( 18a, 18b), delimiting a central compartment (20) which is open upward and inside which said box-like body (21 ) is arranged.

8. The hydraulic pump according to one or more of the preceding claims, characterized in that said sleeves (29, 30) are formed by a cylindrical tubular portion (42) which is inserted in the respective said first, second and third holes (25, 26, 28) for accessing said first and second chambers (22, 23) and in the respective central holes (34) of said flanges (18), and by an end which is associated with the respective said flange (18a, 18b) and has a wider portion (43) which has a larger diameter than said cylindrical tubular portion (42) and forms an annular abutment in contact with the outer face of said respective flange (18a, 18b).

9. The hydraulic pump according to one or more of the preceding claims, characterized in that said box-like body (20) is made of corrosion- resistant material.

10. The hydraulic pump according to the preceding claim, characterized in that said first cup-shaped body (24) and said second cup- shaped body (27) are made of plastic material and/or stainless steel.

1 1. The hydraulic pump according to one or more of the preceding claims, characterized in that said sleeves (29, 30) are made of stainless steel.

12. The hydraulic pump according to one or more of claims 1 to 5 and

7, characterized in that said box-like body (121) is constituted by a first cup- shaped body (124) which is provided laterally, on mutually opposite sides, with a first hole (125) and a second hole (126), and a second cup-shaped body (127), which lies inside the first body (124) and is provided laterally with a third hole (128) which is aligned with the first hole (125), said second cup-shaped body (127) protruding from the bottom (144) of said first cup-shaped body (124) and being monolithic therewith.

13. The hydraulic pump according to the preceding claim, characterized in that the first sleeve (129) is arranged so as to pass through a first central hole of a first flange (1 18a) until it enters said first hole ( 125), while the second sleeve (130) is arranged so as to pass through a second central hole of the second flange (1 18b) until it enters said second hole (126).

14. The hydraulic pump according to claims 12 and 13, characterized in that said first hole (125) of the first cup-shaped body (124) and the third hole (128) of the second cup-shaped portion (127) are connected by a tubular portion (145), which is also monolithic with the first cup-shaped body (124) and the second cup-shaped body (127).

15. The hydraulic pump according to one or more of claims 12 to 14, characterized in that said first cup-shaped body (124) and said second cup- shaped body (127) which protrudes from it monolithically are substantially concentric.

16. The hydraulic pump according to one or more of claims 12 to 15, characterized in that the space formed by the contour of the footing (117) comprised between the box-like body (121) and said flanges (1 18a, 1 18b), crossed by said sleeves (129, 130), is open upward.

17. The hydraulic pump according to one or more of claims 12 and 16, characterized in that said lower edge (1 1 Ia) of said jacket (1 1 1) is fixed so as to rest on a corresponding shoulder (146) which is formed on the facing upper part of said first cup-shaped body (124).

18. The hydraulic pump according to one or more of claims 12 to 17, characterized in that on the outside of the wall of the first cup-shaped body (124), at the shoulder (146) for supporting and fixing the lower edge (1 1 Ia) of the jacket (11 1 ), there is an annular slot (132), which is open outward, for a gasket ( 133 ) for forming a seal on the j acket (1 1 1).

19. The hydraulic pump according to one or more of claims 12 to 18, characterized in that said second cup-shaped body (127) is surmounted by an annular element (147) for supporting the assembly (1 12).

20. The hydraulic pump according to one or more of claims 12 to 19, characterized in that on the inside walls of said first hole (125) and of said second hole (126) there are respective seats (136) for additional gaskets (137) for forming a seal on the outer surface of the respective said sleeves (129, 130).

21. The hydraulic pump according to one or more of claims 12 to 20, characterized in that said box-like body (121 ) is made of corrosion-resistant material.

22. The hydraulic pump according to one or more of claims 12 to 21 , characterized in that said box-like body (121) is made of plastic material or stainless steel or other similar and equivalent material.

23. The hydraulic pump according to one or more of the preceding claims, characterized in that said footing (17, 1 17) is made of cast iron.