CN106168211B

CN106168211B - Gear pump

Info

Publication number: CN106168211B
Application number: CN201610336905.5A
Authority: CN
Inventors: 马克·圭德蒂
Original assignee: Casappa SpA
Current assignee: Casappa SpA
Priority date: 2015-05-06
Filing date: 2016-05-20
Publication date: 2020-03-03
Anticipated expiration: 2036-05-20
Also published as: CN106168211A

Abstract

A gear pump, comprising: -a housing cavity (20) of said gear, which transfers energy to the fluid passing through the pump (1); -a first duct (21) which develops from the containing chamber (20), the first duct (21) being a delivery duct in a first operating mode; -a first reinforcing rib (31) passing through the first duct (21) and dividing the flow of fluid into at least two portions.

Description

Gear pump

Technical Field

The invention relates to a gear pump and a method for constructing the gear pump.

Background

Gear pump means a pump: energy is transferred into the fluid passing through the pump by a volume change induced by engagement of the two bodies.

Known gear pumps comprise:

-a housing chamber housing a body that transfers energy to a fluid passing through the pump;

-a suction duct causing the fluid to be treated to flow into the housing chamber;

-a delivery conduit causing fluid to flow under pressure out of the containment chamber.

One disadvantage of gear pumps is that, due to the high pressures occurring in the region of the conveying lines, the conveying lines need to be reinforced. In this way, the pressure and deformation are reduced to the advantage of correct functioning, but the overall size of the pump is increased due to the greater thickness required.

Disclosure of Invention

In this context, the technical task underlying the present invention is to provide a pump that enables the overall dimensions to be reduced without hindering the correct operation and reliability thereof.

The technical task and the specific objects stated are substantially achieved by a gear pump comprising:

a containment cavity of the gear pump that transfers energy to fluid passing through the gear pump;

-a first conduit deployed from the containment chamber, the first conduit being a delivery conduit in a first mode of operation;

wherein the gear pump comprises a first stiffening rib passing through the first duct and for dividing the flow of fluid passing at the first stiffening rib into at least two portions; the first reinforcing rib includes:

-a first surface and a second surface, opposite to each other;

-a leading edge and an outlet edge of the first reinforcing rib, the leading edge and the outlet edge being rounded and interconnecting the first and second surfaces.

Drawings

A better understanding of the further features and advantages of the present invention will be facilitated by a rough, non-limiting description of a preferred, but not exclusive, embodiment of a gear pump according to the present invention, with reference to the accompanying drawings, in which:

figure 1 illustrates a front view of a pump according to the invention;

figure 2 shows a diagram of a pump according to section F-F of figure 1;

figure 3 shows a diagram of a pump according to section a-a of figure 1;

FIG. 4 shows a diagram of a pump according to section B-B of FIG. 1

Detailed Description

In the drawings, reference numeral 1 denotes a gear pump.

The pump 1 comprises a housing 20 housing the gear, which housing 20 transfers energy to the fluid passing through the pump 1. Advantageously, the gear comprises two cogged wheels, which are mutually meshed and are located in the housing cavity 20. One of the gears may have external teeth and the other internal teeth. More generally, the two gears may be rolling bodies that interact with each other, but do not have an involute profile (e.g., a lobe pump).

The pump 1 further comprises a first duct 21, the first duct 21 being flared from the housing cavity 20. In a first mode of operation, the first conduit 21 is a delivery conduit. Said first duct 21 is therefore used to discharge the fluid under pressure from the chamber 20.

The pump 1 comprises a first stiffening rib 31, which first stiffening rib 31 passes through said first duct 21. The first reinforcing rib 31 divides the flow of the fluid into at least two portions. Which converge again downstream of said first rib 31.

The first ribs thus serve to stiffen the conveying pipe, minimizing the tension of the material and thus minimizing deformation without oversizing the wall thickness of the first pipe 21. Therefore, it is possible to minimize the outer size of the pump 1.

The first stiffener 31 includes a fin 310, the fin 310 having an aerodynamic profile. This minimizes the pressure drop. In the case of a reversible pump, there may be more important advantages, as explained more properly below.

The pump 1 advantageously comprises a second duct 22, the second duct 22 terminating in said housing chamber 20. In the first mode of operation, the second conduit 22 is a suction conduit.

The pump 1 further comprises a second stiffening rib 32, which second stiffening rib 32 passes through said second duct 22.

Advantageously, the pump 1 is reversible. Thus, the pump may also be operated in a second mode of operation, in which the first conduit 21 becomes a suction conduit and the second conduit 22 becomes a delivery conduit.

In view of the reversibility of the pump 1, it is therefore important that the ribs 32 are also present in the second conduit 22. In fact, this second conduit 22 may also become a delivery conduit and therefore be subjected to a large amount of pressure due to the fluid subjected to pressure.

Conveniently, the second stiffener 32 includes a fin 320, the fin 320 having an aerodynamic-type profile.

In the first mode of operation, this feature serves to minimize the pressure drop on the suction side in order to reduce the risk of cavitation (in the first mode of operation, the second rib 32 operates under suction, and the aerodynamic profile contributes to this purpose).

Advantageously, the first duct 21 and the second duct 22 comprise two

openings

23, 24, the

openings

23, 24 being located side by side on the same wall of the pump 1, facing towards the outside. Inside the pump, the first and

second ducts

21, 22 extend side by side.

In an alternative embodiment, the two

openings

23, 24 of the first duct 21 and the second duct 22 can be located on two different walls of the pump 1; in particular, the two

openings

23, 24 may be transverse.

Conveniently, the first duct 21 and the second rib 31 are a single integrally formed body.

In a preferred embodiment, the second duct 22, the second rib 32 and at least a portion of the receiving cavity 20, in addition to the first duct 21 and the first rib 31, are in a single integrally formed body. The single, integrally formed body is advantageously made of cast iron. The single, integrally formed body also defines an outer housing which at least partially delimits the pump 1 and the outside.

As illustrated in fig. 4, the first duct 21, the second duct 22, the first rib 31 and the second rib 32 and at least a portion of the housing cavity are symmetrical with respect to a median plane 4 interposed between said first duct 21 and second duct 22.

The first rib 31 includes:

a first surface 311 and a second surface 312, opposite each other;

a leading edge 313 and an outlet edge 314 of the first rib 31, the leading edge 313 and the outlet edge 314 being rounded and being interconnected to the first surface 311 and the second surface 312.

With respect to the path extending from the housing cavity 20 along the first duct 21 towards the outside of the pump 1, the first 311 and second 312 surfaces comprise a portion 315, in which portion 315 the first 311 and second 312 surfaces diverge from each other, and a portion 316, in which portion 316 the first 311 and second 312 surfaces converge towards each other.

One of the two portions of the flow divided by said first rib 31 sweeps the first surface 311 and the other portion sweeps the second surface 312.

The first duct 21 comprises a first delimiting wall 25, the first delimiting wall 25 facing the first surface 311 and defining a concavity facing the first surface 311. Similarly, the first duct 21 comprises a second delimiting wall 26, the second delimiting wall 26 facing the second surface 312 and defining a concavity facing the second surface 312.

The first rib 31 is connected to the remainder of the integrally formed body opposite at its first end 317 and second end 318. The first end 317 is closer to the outer surface of the pump than the second end 318.

The surface of at least one lateral portion intermediate with respect to the first end 317 and the second end 318 is smaller than the surface of the lateral portion measured at the first end 317 and the second end 318. In particular, the mid-portion has a chord and/or average thickness that is less than the chord and/or average thickness of the lateral portions measured at the first end 317 and the second end 318. The above mentioned transversal portion is realized along a plane oriented according to the direction of the fluid and transversal to the direction in which the first 317 and second 318 ends join.

In certain embodiments, the first rib 31 has a larger transverse portion at the first end 317 than at the second end 318.

Conveniently, what has been described above in connection with the first rib 31 and/or the first duct 21 may be repeated for the second rib 32 and/or the second duct 22.

Thus, the invention as conceived is able to obtain a plurality of advantages.

First, the present invention enables the overall size of the pump 1 to be reduced. In fact, the first rib 31 (located in the first duct 21) is able to reinforce the delivery side of the pump 1 without increasing the thickness of the duct. Furthermore, in the case where the pump operates in reversible mode and the first duct 21 acts as a suction duct, the aerodynamic shape of the fins makes it possible to avoid a significant pressure drop (and consequent risk of cavitation) on the suction side

Therefore, without departing from the concept of the invention, several variations and modifications can be made, which are within the scope of the invention. Moreover, all the details of the invention may be substituted by technically equivalent elements. In practice, all the materials used, as well as the dimensions, may be of any type according to requirements.

Claims

1. A gear pump, comprising:

-a containment cavity (20) of the gear pump, which transfers energy to the fluid passing through the gear pump;

-a first duct (21) which develops from the containing chamber (20), the first duct (21) being a delivery duct in a first operating mode;

characterized in that the gear pump comprises a first stiffening rib (31) passing through the first duct (21) and for dividing the flow of fluid passing at the first stiffening rib (31) into at least two portions; the first reinforcing rib (31) includes:

-a first surface (311) and a second surface (312), opposite each other;

-a leading edge (313) and an outlet edge (314) of the first reinforcement rib (31), the leading edge (313) and the outlet edge (314) being rounded and interconnecting the first surface (311) and the second surface (312).

2. Gear pump according to claim 1, characterized in that the first stiffening rib (31) comprises a fin (310), the fin (310) having an aerodynamic profile.

3. Gear pump according to claim 1, characterized in that it comprises:

-a second duct (22) terminating in the housing chamber (20), the second duct (22) being a suction duct in the first operating mode;

-a second stiffening rib (32) passing through the second duct (22);

the gear pump is reversible and can be operated in a second operating mode in which the first duct (21) becomes a suction duct and the second duct (22) becomes a delivery duct.

4. Gear pump according to claim 3, characterized in that the second stiffening ribs (32) comprise fins (320), the fins (320) having an aerodynamic profile.

5. Gear pump according to claim 1, characterized in that the first duct (21) and the first reinforcement rib (31) are in a single integrally formed body.

6. Gear pump according to claim 3, characterized in that the first duct (21), the second duct (22), the first and second stiffening ribs (31, 32) and at least part of the receiving cavity (20) are in a single integrally formed body.

7. Gear pump according to claim 3, characterized in that said first duct (21) and said second duct (22), said first (31) and second (32) stiffening ribs, and at least a portion of said housing cavity (20) are symmetrical with respect to a median plane (4) interposed between said first duct (21) and second duct (22), respectively.

8. Gear pump according to claim 7, characterized in that said first stiffening ribs (31) comprise, with respect to the path extending from said housing cavity (20) along said first duct (21) towards the outside of said gear pump:

-a first portion (315), in which first portion (315) the first surface (311) and the second surface (312) are separated from each other; and

-a second portion (316), in which second portion (316) the first surface (311) and the second surface (312) converge towards each other.

9. Gear pump according to claim 5 or 6, characterized in that said first reinforcement rib (31) is connected to the remaining part of the unitary body opposite at its first (317) and second (318) ends;

at least one transverse portion intermediate with respect to the first (317) and second (318) ends has a smaller surface than the transverse portion measured at the first and second ends.