EP3701149B1

EP3701149B1 - A pump manifold

Info

Publication number: EP3701149B1
Application number: EP18789224.5A
Authority: EP
Inventors: Giuseppe Orlandini
Original assignee: Annovi Reverberi SpA
Current assignee: Annovi Reverberi SpA
Priority date: 2017-10-26
Filing date: 2018-10-03
Publication date: 2022-11-23
Anticipated expiration: 2038-10-03
Also published as: CN111630272B; WO2019082002A1; AR113373A1; CN111630272A; IT201700121760A1; EP3701149A1

Description

TECHNICAL FIELD

The present invention concerns a manifold for a multistage pump provided with a plurality of pumping chambers, in particular a manifold for a multistage diaphragm pump the pumping chambers of which are in parallel.

PRIOR ART

Pumps generally comprise a casing, a head fixed to the casing and a pumping chamber formed in the head and provided with a suction duct and a delivery duct that open into the pumping chamber.
There are known multi-stage pumps provided with a plurality of pumping chambers arranged in parallel to one another, which are usually provided with a suction manifold, which internally defines a duct through which a work fluid coming from a tank reaches each pumping chamber.
Such multi-stage pumps also comprise a delivery manifold, which internally has a duct that collects the pressurized fluid coming out from the delivery ducts and directs it towards a single outlet, connected in various ways to a tool and/or a device for dispensing pressurized fluid.
Such manifolds are commonly made in a single monolithic aluminium body in order to keep down the weight of the pump.
A problem of this solution is the relatively high cost of the material used. Alternatively the manifolds can be made in many elements of polymeric material, for example obtained by injection moulding, which are assembled to make the manifold.
In such a solution every element constitutes a complete segment of the duct of the manifold, i.e. two adjacent elements are joined together along an imaginary plane perpendicular to the axis of the duct at the joining area. In documents WO2017/153808 , EP0468808 , GB2144493 is disclosed such a solution.
Generally, for a manifold having an annular shape intended for a pump with three pumping chambers in parallel at least six elements are necessary.
In order to assemble such elements it is necessary to have sealing gaskets and fixing means between one element and the other that are used to avoid losses of the work fluid, and it is thus clear that, taking into consideration the time necessary for assembly as well as the cost of the gaskets and of the fixing means, this solution also has relatively high costs.
There is thus a great need to reduce the production costs of such manifolds, with a simple, rational and low-cost solution.
A purpose of the present invention is to satisfy such requirements.
Such purposes are accomplished by the characteristics of the invention given in the independent claim.
The dependent claims outline preferred and/or particularly advantageous aspects of the invention.

SUMMARY OF THE INVENTION

The invention provides a manifold for a multistage pump provided with a plurality of pumping chambers, wherein the manifold comprises a body which is so shaped as to define a duct extending along a path and exhibiting an access mouth and a plurality of connection mouths, wherein each connection mouth is adapted to be connected to a corresponding pumping chamber of the pump, wherein the body is subdivided into at least a first portion and a second portion at a secant plane parallel to a plane whereon the path is lying, and wherein the path is a closed ring path.
Thanks to such a solution, a manifold for a multistage pump, i.e. provided with a plurality of pumping chambers in parallel, is provided that is simple and cost-effective to make.
One aspect of the invention foresees that the path is curved.
In this way, the duct does not hinder the connection of the pump, on which the manifold is installed, to a drive shaft, for example the drive shaft of a power take-off.
A further aspect of the invention foresees that the first portion and the second portion can constitute the entire body of the manifold.
In this way, the manifold is particularly quick and simple to make, since from the assembly of only two elements it is possible to make the entire duct. According to an aspect of the invention the first portion and the second portion of the body can be made of polymeric material.
Thanks to such a solution the manifold is light and at the same time simple and cost-effective to make.
According to another aspect of the invention, the first portion and the second portion of the body can be made separately by injection molding and joined by welding.
In this way, it is simpler and quicker to make with respect to making the plastic manifolds of the prior art, since the manifold does not require the presence of sealing gaskets between portions of the manifold itself.
Preferably, the access mouth and the connection mouths can be made in the first portion of the body.
In this way, only one of the molds for making the portions of the manifold must have moveable projections and/or pistons for the creation of the holes of the mouths. Or, alternatively, in this way only one of the two portions must undergo the perforation processes for the creation of the mouths after the step of making the portions by injection molding. In this way, the manufacturing costs and times of the manifold are reduced.
According to another aspect of the invention, the first portion comprises a joining edge adapted to be placed in contact with a corresponding joining edge of the second portion, wherein one between the joining edge of the first portion and the joining edge of the second portion exhibits a cord adapted to contact a flat surface of the joining edge of the other portion.
In this way, the joining by welding of the first portion with the second portion is facilitated.
The invention also provides a multistage pump comprising a plurality of pumping chambers and a manifold, according to any one of the aspects of the invention described above, wherein each connection mouth is connected to a corresponding pumping chamber of the pump.
For example, the multistage pump can comprise an additional manifold, according to any one of the aspects of the invention described above, wherein the second portion of the manifold is equal to the second portion of the further manifold.
In this way, the production process of the multistage pump is simplified and made more cost-effective.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will become clear from reading the following description, provided as an example and not for limiting purposes, with the help of the figures illustrated in the attached tables.

Figure 1 is a perspective view of a delivery manifold according to the invention.
Figure 2 is a front view of figure 1.
Figure 3 is a section view according to the plane III-III of figure 2
Figure 4 is an enlargement of figure 3
Figure 5 is a side view of figure 1.
Figure 6 is a section view according to the plane VI-VI of figure 5.
Figure 7 is an axonometric view of a second portion of the delivery manifold of the previous figures.
Figure 8 is an axonometric view of a first portion of the delivery manifold of the previous figures
Figure 9 is a perspective view of a suction manifold according to the invention.
Figure 10 is a front view of figure 9.
Figure 11 is a section view according to the plane XI-XI of figure 10
Figure 12 is an enlargement of figure 11
Figure 13 is a section view according to the plane XIII-XIII of figure 11
Figure 14 is a multistage pump provided with a duct according to the invention.
Figure 15 is a side view of figure 14.
Figure 16 is a partial section view according to the plane XVI-XVI of figure 15.

DETAILED DESCRIPTION

With particular reference to figures 14 to 16, a multistage pump, for example a diaphragm pump, provided with a plurality of pumping chambers 15 has been globally indicated with 10.
It should be specified that in this document the term multistage pump is meant to indicate a pump in which the pumping chambers are in parallel with one another, i.e. in which the pressure difference between upstream and downstream of every pumping chamber is the same for all of the pumping chambers.
The pump 10 comprises a casing 20 and a shaft 25, which is rotatably associated with said casing 20 and at least partially contained in it.
Said shaft 25 comprises a cam 26 rotating as a unit with the shaft itself. Moreover, the shaft 25 comprises a grooved shank 30 adapted for being coupled with a matching grooved shank of a drive shaft, for example of a power take-off of a vehicle.
For example, the shaft 25 can comprise an end projecting externally from the casing 20, provided with said grooved shank 30.
The pump 10 can be provided with a protective collar (not illustrated) adapted for embracing the grooved shank 30 in the radial direction.
For example, the pump 10 comprises a tank of lubricant fluid T fixed to the casing 20, for example outside of it.
The pump 10 comprises a foot 35, for example two feet 35, fixedly connected to the casing 20 and adapted for supporting the pump 10 resting on a flat surface so that the axis of the shaft 25 is substantially parallel to the plane on which said flat surface is lying.
The feet 35 each comprise a plurality of holes adapted for allowing the pump 10 to be fixed to a vehicle or a tool through threaded connections.
The pump 10 is provided with a plurality of cylinders 40, for example three of them, the central axes of which are perpendicular to the axis of the shaft 25. Each cylinder 40 is made inside the casing 20.
For example, the cylinders 40 are equally angularly spaced apart with respect to the axis of the shaft 25.
The pump 10 comprises a plurality of pistons 41, each slidably received in a respective cylinder 40 and associated with the shaft 25 through a connecting rod 27, which at one end is hinged to the piston and at the opposite end has a concave surface on which the cam 26 of the shaft 25 slides.
The pump 10 is provided with a plurality of heads 45, for example three of them, each fixed to the free end of a respective cylinder 40 and in which the respective pumping chamber 15 is formed.
Each pumping chamber 15 is partially delimited by an elastic membrane 42, which is deformable, under the thrust of the piston, between a first position in which the volume of the pumping chamber 15 is maximum and a second position in which the volume of the pumping chamber 15 is minimum. Moreover, every pumping chamber 15 comprises a delivery duct 50 and a suction duct 55 formed in the respective head 45, each of which is provided with an inner opening communicating with the pumping chamber 15 and an opposite outer opening 65, for example circular in shape, formed on an outer surface of the head 45.
Preferably, the outer openings 65 of the delivery ducts 50 lie on a same plane, distinct from the plane on which the outer openings 65 of the suction ducts 55 lie.
Moreover, the outer openings 65 are equally angularly spaced apart with respect to the axis of the shaft 25.
With particular reference to figures 9 to 13, the pump 10 comprises a suction manifold 70, adapted for placing a source of a fluid to be pressurized in communication with each pumping chamber 15.
The suction manifold 70 comprises a body 75, as will be described better hereinafter, provided with an inner cavity defining a duct 80.
The duct 80 extends along a path P.
The path is representative of the set of rectilinear and/or curved segments of the duct itself.
Preferably, the path is an imaginary line formed by the set of centers of the cross sections of the duct 80.
For example, such cross sections are defined by planes perpendicular to the advancing direction of the fluid in the corresponding segment of the duct 80. Preferably, the path P lies on a single plane, i.e. the imaginary line formed by the set of centers of the cross sections of the duct lies on a single plane.
For example, the path P is a closed loop path.
In the illustrated embodiment, the closed path P approximates the perimeter of an equilateral triangle (see figure 13).
Specifically, said equilateral triangle has sides lying on the same plane and curved, i.e. provided with a concavity facing towards the center of the triangle itself.
This does not rule out the possibility that alternatively the path P defined by the duct 80 can approximate a circle or an ellipse or any other polygon.
In the illustrated embodiment, the duct 80 comprises a plurality of longitudinal segments.
For example, the duct 80 comprises a longitudinal segment first 81a, a second longitudinal segment 81b and a third longitudinal segment 81c.
Every segment 81a,81b,81c has a longitudinal axis lying on the same plane as the longitudinal axes of the other segments 81a,81b,81c.
Preferably, the first segment 81a, the second segment 81b and the third segment 81c have a cross section (i.e. substantially perpendicular to a longitudinal axis of the segment itself) that is closed, for example rectangular in shape (with rounded vertices).
The duct 80 can also comprise a plurality of chambers 81d, each arranged between two longitudinal segments and placed in fluid communication with them.
For example, the duct 80 comprises a plurality of chambers 81d, for example in three of them, each adapted for connecting the ends of two adjacent segments 81a,81b,81c.
Said chambers 81d are arranged at the vertices of the triangle defined by the path P of the duct 80.
The chambers 81d are shaped like cylindrical surfaces, for example provided with a central axis perpendicular to the longitudinal axes of the adjacent longitudinal segments
For example, such cylindrical surfaces comprise joining openings adapted for placing every chamber 81d in communication with the respective adjacent segments.
The chambers 81d have a greater cross section than the cross section of the longitudinal segments.
The duct 80 of the suction manifold 70 comprises a plurality of connection mouths 85, for example circular in shape, formed in the body 75.
Each connection mouth 85 is connected to the suction duct 55 of a corresponding pumping chamber 15.
In the preferred embodiment, the duct 80 comprises three connection mouths 85, one for every pumping chamber 15.
This does not rule out the possibility that the duct 80 can comprise more than three connection mouths 85, for example one for every pumping chamber 15. The connection mouths 85 all face in the same direction, for example said connection mouths 85 lie on a same plane.
The connection mouths 85 are equally spaced apart along the duct 80, for example, every connection mouth 85 is positioned between at least two adjacent segments 81a,81b,81c.
Specifically, every connection mouth 85 is formed at a respective chamber 81d.
Moreover, the central axes of the connection mouths 85 are substantially perpendicular to the longitudinal axes of the adjacent segments 81a,81b,81c, i.e. said central axes are perpendicular to the path P.
For example, the connection mouths 85 have a central axis arranged close to, for example at, a respective vertex of the triangle defined by the path P of the duct 80.
Every connection mouth 85 is provided with a centering ring 90.
The centering ring 90 is provided with an outer surface 100, for example cylindrical.
The outer surface 100 has a central axis parallel to the central axis of the respective connection mouth 85.
Each connection mouth 85 also comprises a fixing plate 110.
Such a plate 110 has a pair of through hole 115, for example arranged beside the respective connection mouth 85 in diametrically opposite positions with respect to it.
The through holes 115 have central axes parallel to the central axis of the respective connection mouth 85.
Every through hole 115 can comprise a bushing (not illustrated), for example made of metallic material, inserted concentrically to it.
The duct 80 of the suction manifold 70 also comprises an access mouth 125, for example circular in shape, formed in the body 75.
Said access mouth 125 places the duct 80 in communication with the outside. In particular, the access mouth 125 of the suction manifold 70 is adapted to be connected, for example through pipes, to a container of a fluid to be pressurized.
The access mouth 125 is preferably arranged between two connection mouths 85 and is, for example, equally spaced from them.
For example, the access mouth 125 is formed in the first segment 81a of the duct 80.
Preferably, the access mouth 125 lies on a different plane from the plane on which the connection mouths 85 lie.
The access mouth 125 comprises a collar 125a for removably fixing a pipe, for example said collar 125a projects towards the outside of the duct 80. Preferably, the collar 125a has a longitudinal axis parallel to the plane on which the connection mouths 85 are lying.
The body 75 which is so shaped as to define the duct 80 has a substantially annular shape.
In practice, the body 75 is provided with an inner surface 130, which delimits the duct 80 in the radial direction, and with an outer surface 135, opposite to the inner surface 130.
The outer surface 135 defines a central opening 140, which does not communicate with the duct 80.
The body 75 has a wall 145 (defined as the body portion 75 comprised between the outer surface 135 and the inner surface 130) the thickness of which is practically constant along the entire path P of the duct 80.
The body 75 comprises a first portion 75a and a second portion 75b substantially subdivided at a secant plane A parallel to a plane whereon the path P is lying.
For example, the secant plane A lies on the same plane whereon the path P is lying.
Of course, the first portion 75a and the second portion 75b can have projecting or recessed portions with respect to the secant plane A without for this reason departing from the scope of protection of the claims.
In the illustrated embodiment the secant plane A is also parallel to a plane on which the connection mouths 85 are lying.
Preferably, the body 75 and the duct 80 consist of the union of the first portion 75a and the second portion 75b.
For example, the first portion 75a and the second portion 75b are shaped as matching shells the union of which forms the body 75 and defines the duct 80. The first portion 75a of the body 75 defines a first part 80a of the duct 80 and the second portion 75b of the body 75 defines a second part 80b of the duct 80.
In other words, the first portion 75a comprises a first part 130a, for example concave, of the inner surface 130 of the body 75, in which the first part 130a defines the first part 80a of the duct 80 and the second portion 75b comprises a second part 130b, for example concave, of the inner surface of the body 75, in which the second part 130b defines the second part 80b of the duct 80. For example, the first portion 75a comprises a first part 145a of the wall 145, in which the first part 145a of the wall 145 defines the first part 130a of the inner surface 130 and the second portion 75b comprises a second part 145b of the wall 145, in which the second part 145b of the wall 145 defines the second part 130b of the inner wall 130.
The first portion 75a defines a first part of every segment 81a,81b,81c of the duct 80 that with a second part of every segment 81a,81b,81c defined by the second portion 75b, completely forms every segment 81a,81b,81c. Moreover, the first portion 75a defines a first part of every chamber 81d that with a second part of every chamber 81d defined by the second portion 75b, completely forms every chamber 81d.
In practice, every portion 80a,80b of the duct 80 corresponds to the volume comprised between the respective part 130a,130b of inner surface 130 and the secant plane A.
The first portion 75a comprises a joining edge adapted to be placed in contact with a corresponding joining edge of the second portion 75b.
Each joining edge extends all along a perimeter of the respective portion formed by the intersection of the respective portion 75a,75b with a plane parallel to the secant plane A and proximal to it, for example formed by the intersection of the respective portion 75a,75b of the body 75 with the secant plane A.
In the illustrated embodiment, the first portion 75a comprises a first joining edge 270a and a second joining edge 275a, each of which extends along an entire corresponding intersection perimeter formed by the intersection of the wall 145 with a plane parallel to the secant plane A and proximal to it, for example with the secant plane A.
In other words, the first joining edge 270a and the second joining edge 275a of the first portion 75a are arranged at the respective ends of the first part 145a of the wall 145 facing towards the secant plane A.
The second portion 75b comprises a first joining edge 300b and a second joining edge 305b each of which extends along an entire corresponding intersection perimeter formed by the intersection of the wall 145 with a plane proximal to the secant plane A and parallel to it, for example with the secant plane A. In other words, the first joining edge 300b and the second joining edge 305b of the second portion 75b are arranged at the respective ends of the second part 145b of the wall 145 facing towards the secant plane A.
One among the joining edge of the first portion 75a and the joining edge of the second portion 75b exhibits a cord adapted for contacting a surface, for example flat, of the joining edge of the other portion.
For example, each joining edge 270a,275a of the first portion 75a comprises a surface 280a, 285a, for example flat, preferably parallel to the secant plane A.
In the preferred embodiment each surface 280a, 285a lies on the secant plane A.
Every surface 280a, 285a delimits an end of the first part 145a of the wall 145. Each joining edge 300b,305b of the second portion 75b comprises a surface 310b,315b, for example flat, preferably parallel to the secant plane A.
Each joining edge 300b,305b of the second portion 75b comprises a cord 320b,325b, for example that rises up from an end of the second part 145b of the wall, adapted for contacting the respective flat surface 280a,285a of the corresponding joining edge 270a,275a of the first portion 75a.
Preferably, each cord 320b,325b rises up from a surface 310b,315b of the respective joining edge 300b,305b of the second portion 75b, for example flat, preferably parallel to the secant plane A.
Every surface 310b,315b delimits an end of the second part 145b of the wall 145.
Each cord 320b,325b of the second portion 75b contacts, for example along the entire longitudinal extension thereof, the surface 280a, 285a of the joining edge 270a,275a of the first portion 75a.
Each cord 320b,325b follows a path that approximates the path P of the duct 80.
In the illustrated embodiment, each cord 320b,325b contacts the respective surface 280a, 285a along a contact surface that has a width, i.e. linear extension along a plane transversal to the duct 80, comprised between 0.2 and 0.8 times the thickness of the wall 145.
Each cord 320b,325b is shaped, at every through hole 115, like a cylindrical wall concentric to the axis of the respective hole 115.
Each joining edge 270a,275a of the first portion 75a has, at every through hole 115, a cylindrical wall that rises up from a surface 280a, 285a of the respective joining edge 270a,275a of the first portion 75a and is internally concentric to the cylindrical wall of the respective cord 320b,325b of the second portion 75b. Preferably, the inner surface of every cylindrical wall corresponds to the cylindrical wall of the corresponding hole 115.
Each joining edge 270a,275a, 300b,305b also comprises a further cord projecting with respect to the corresponding part of the wall 145 in the opposite direction with respect to the duct 80.
The access mouth 125 and the connection mouths 85 are made only in the first portion 75a of the body 75.
In other words, the connection mouths 85 and the access mouth 125 are made in the first part 145a of the wall 145.
The second portion 75b of the body 75 does not have mouths or openings adapted for placing the duct 80 in communication with the outside, i.e. the second portion 145b of wall 145 is continuous along every cross section of the manifold 70.
The first portion 75a has, at the access mouth 125, a portion 340a of the first part 145a of the wall 145 projecting beyond the secant plane A and received in a recessed portion 345b of the second part 145b of the second portion 75b. The joining edges of the first portion 75a and of the second portion 75b follow the profile of the projecting portion 340a and of the recessed portion 345b.
In this way, it is possible to make an access mouth of large dimensions with respect to the section of the duct without having to make said access mouth in part in the first portion and in part in the second portion.
Every portion 75a,75b consists of a monoblock made of plastic material, for example by injection molding.
It should be specified that the term monoblock is meant to indicate an object devoid of joining points, i.e. not made by the joining of plural parts and in which any section consists of the same body.
Furthermore, the term monoblock body is meant to indicate a body consisting of the solidification of a single volume of a fluid.
The plastic material of which each portion 75a,75b consists can for example be polyethylene, polypropylene or polyamide.
The first portion 75a and the second portion 75b are joined by welding to form the body 75.
For example, the first portion 75a and the second portion 75b are joined by friction welding.
In particular, each cord 320b,325b of the second portion 75b is pressed and simultaneously moved cyclically, i.e. rubbed, against the respective surface 280a, 285a of the joining edge 270a,275a of the first portion 75a until the material is brought into the plastic phase, after which the first portion 75a and the second portion 75b are kept pressed without relative movement between the two parts until the material cools down.
The suction manifold 70 is fixed to the pump 10 through threaded members inserted, through the through hole 115 of every fixing plate 110, in suitable threaded elements, for example nuts, inserted in the corresponding heads 45. The suction manifold 70 is fixed so that every connection mouth 85 faces onto the outer opening 65 of a respective suction duct 55.
Moreover, every centering ring 90 is inserted, for example with low clearance, in a seat 95 formed in a respective opening 65 of a suction duct 55 (see figure 9).
In practice, the outer surface 100 of the centering ring 90 is inserted in contact in a matching inner surface 105, for example cylindrical, of the seat 95.
In addition, when the suction manifold 70 is fixed to the pump 10, the central opening 140 of the outer surface 135 of the body 75 embraces, with substantial clearance, a further grooved shank of the shaft 25 opposite to the shank 30 and for example, a protective collar of said grooved shank (not illustrated in the figures).
Between every connection mouth 80 and every respective pumping chamber 15 an automatic unidirectional valve 215 is arranged, which is housed in a seat 220 formed in a respective suction duct 55.
With particular reference to figures 1 to 8, the pump 10 comprises a delivery manifold 150, adapted for placing each pumping chamber 15 in communication with a dispenser of the pressurized fluid and/or a device fed by the pressurized fluid.
The delivery manifold 150 is substantially shaped like the suction manifold 70. The delivery manifold 150 comprises a body 155, as will be described better hereinafter, provided with a cavity shaped to define a duct 160.
The duct 160 extends along a path P.
Preferably, the path P of the duct 160 of the delivery manifold 150 is identical to that of the duct 80 of the suction manifold 70.
The duct 160 comprises a plurality of longitudinal segments.
For example, the duct 160 comprises a first longitudinal segment 161a, a second longitudinal segment 161b and a third longitudinal segment 161c.
For example, said segments 161a,161b,161c are shaped like the segments 81a,81b,81c of the duct 80 of the suction manifold 70.
Moreover, the duct 160 comprises a plurality of chambers 161d, each arranged between two longitudinal segments of the duct 160 and placed in fluid communication with them.
For example, the duct 160 comprises three chambers 161d, each adapted for connecting the ends of two adjacent segments 161a,161b,161c.
Said chambers 161d are arranged at the vertices of the triangle defined by the path P of the duct 160.
The chambers 161d are shaped like cylindrical surfaces, for example provided with a central axis perpendicular to the longitudinal axes of the adjacent longitudinal segments.
For example, such cylindrical surfaces comprise joining openings adapted for placing every chamber 161d in communication with the respective adjacent segments.
The chambers 161d have a greater cross section than the cross section of the longitudinal segments.
The duct 160 of the delivery manifold 150 comprises a plurality of connection mouths 165, for example circular in shape, formed in the body 155.
In the preferred embodiment, the duct 160 comprises three connection mouths 165, one for every pumping chamber 15.
This does not rule out the possibility that the duct 160 can comprise more than three connection mouths 165, for example one for every pumping chamber 15. The connection mouths 165 all face in the same direction, for example said connection mouths 165 lie on one same plane.
The connection mouths 165 of the delivery manifold 150 are equally spaced apart along the duct 160.
For example, every connection mouth 165 is positioned between at least two adjacent segments 161a,161b,161c.
Specifically, every connection mouth 165 is formed at a respective chamber 161d.
Moreover, the central axes of the connection mouths 165 are substantially perpendicular to the longitudinal axes of the adjacent segments 161a,161b,161c. For example, the connection mouths 165 have a central axis arranged close to, for example at, a respective vertex of the triangle defined by the path P of the duct 160.
Every connection mouth 165 of the delivery manifold 150 is provided with a centering ring 170.
The centering ring 170 is provided with an outer surface 180, for example cylindrical.
The outer surface 180 has a central axis parallel to the central axis of the respective connection mouth 165.
Each connection mouth 165 of the delivery manifold 150 comprises a fixing plate 225.
Such a plate 225 has a pair of through holes 230, for example arranged beside the respective connection mouth 165 in diametrically opposite positions with respect to it.
Each through hole 230 can comprise a bushing (not illustrated), for example made of metallic material, inserted concentrically to it.
The duct 160 of the delivery manifold 150 also comprises an access mouth 240, for example circular in shape, formed in the body 155.
Said access mouth 240 places the duct 160 in communication with the outside. In particular, the access mouth 240 of the delivery manifold 150 is adapted to be connected to a dispenser of the pressurized fluid and/or a device fed by the pressurized fluid.
The access mouth 240 is arranged between two connection mouths 165 and is, for example, equally spaced from them.
For example, the access mouth 240 is formed in the first segment 161a of the duct 160.
Preferably, the access mouth 240 lies on a different plane from the plane on which the connection mouths 165 are lying.
The access mouth 240 comprises a collar 240a for removably fixing a pipe, for example said collar 240a projects towards the outside of the duct 160. Preferably, the collar 240a has a longitudinal axis parallel to the plane on which the connection mouths 165 are lying.
The duct 160 of the delivery manifold 150 comprises at least one withdrawal mouth 245, for example adapted to be connected to a further dispenser and/or a further device fed by the pressurized fluid.
The withdrawal mouth 245 is formed in the body 160 and has, for example, a circular shape.
Preferably, the duct 160 of the delivery manifold 150 comprises two withdrawal mouths 245.
However, this does not rule out the possibility that the duct 160 can comprise a greater number of withdrawal mouths 245.
Every withdrawal mouth 245 is distinct from the access mouth 240 and can for example have a smaller passage area than the passage area of the access mouth 240.
Each withdrawal mouth 245 is arranged between two connection mouths 165 of the delivery manifold 150 and is, for example, equally spaced from them. Preferably, the withdrawal mouths 245 place the second segment 161b and the third segment 161c of the duct 160 in communication with the outside. Every withdrawal mouth 245 lies on a different plane from the plane on which the connection mouths 165 are lying.
Each withdrawal mouth 245 comprises a collar 245a for removably fixing a pipe, for example said collar 245a projects towards the outside of the duct 160. Preferably, the collar 245a has a longitudinal axis parallel to the plane on which the connection mouths 165 are lying.
Each withdrawal mouth 245 comprises a threading, for example formed on an inner surface of the collar 245a, for removably fixing a pipe provided with a matching threading.
The body 155 of the delivery manifold 150 shaped to define the duct 160 has a substantially annular shape.
In practice, the body 155 is provided with an inner surface 250, which delimits the duct 160 in the radial direction, and with an outer surface 255, opposite to the inner surface 250.
The outer surface 255 defines a central opening 260, which does not communicate with the duct 160.
The body 155 has a wall 265, defined as the body portion 155 comprised between the outer surface 255 and the inner surface 250, the thickness of which is practically constant along the entire path P of the duct 160.
The body 155 comprises a first portion 155a and a second portion 155b substantially subdivided at a secant plane B parallel to a plane whereon the path P is lying.
For example, the secant plane B lies on the same plane whereon the path P is lying.
Of course, the first portion 155a and the second portion 155b can have projecting or recessed portions with respect to the secant plane B without for this reason departing from the scope of protection of the claims.
In the illustrated embodiment, the secant plane B is also parallel to a plane on which the connection mouths 165 are lying.
Preferably, the body 155 and the duct 160 consist of the union of the first portion 155a and the second portion 155b.
For example, the first portion 155a and the second portion 155b are shaped like matching shells the union of which forms the body 155 and defines the duct 160.
The first portion 155a of the body 155 defines a first part 160a of the duct 160 and the second portion 155b of the body 155 defines a second part 160b of the duct 160.
In other words, the first portion 155a comprises a first part 250a, for example concave, of the inner surface 250 of the body 155, in which the first part 250a defines the first part 160a of the duct 160 and the second portion 155b comprises a second part 250b, for example concave, of the inner surface of the body 155, in which the second part 250b defines the second part 160b of the duct 160.
For example, the first portion 155a comprises a first part 265a of the wall 265, in which the first part 265a of the wall 265 defines the first part 250a of the inner surface 250 and the second portion 155b comprises a second part 265b of the wall 265, in which the second part 265b of the wall 265 defines the second part 250b of the inner wall 250.
The first portion 155a defines a first part of every segment 161a,161b,161c of the duct 160 which with a second part of every segment 161a,161b,161c defined by the second portion 155b, completely forms every segment 161a,161b,161c.
Moreover, the first portion 155a defines a first part of every chamber 161d that with a second part of every chamber 161d defined by the second portion 155b, completely forms every chamber 161d.
In practice, every portion 160a,160b of the duct 160 corresponds to the volume comprised between the respective part 250a,250b of inner surface 250 and the secant plane B.
The first portion 155a comprises a joining edge adapted to be placed in contact with a corresponding joining edge of the second portion 155b.
Each joining edge extends along an entire perimeter of the respective portion, formed by the intersection of the respective portion 155a, 155b of the body 155 with the secant plane B, for example formed by the intersection of the respective portion 155a, 155b with a plane proximal to the secant plane B and parallel to it.
In the illustrated embodiment, the first portion 155a comprises a first joining edge 350a and a second joining edge 355a, each of which extends along an entire corresponding intersection perimeter formed by the intersection of the wall 265 with the secant plane B, for example with a plane proximal to the secant plane B and parallel to it.
In other words, the first joining edge 350a and the second joining edge 355a of the first portion 155a are arranged at the respective ends of the first part 265a of the wall 265 facing towards the secant plane B.
The second portion 155b comprises a first joining edge 360b and a second joining edge 365b each of which extends along an entire corresponding intersection perimeter formed by the intersection of the wall 265 with a plane proximal to the secant plane B and parallel to it, for example with the secant plane B.
In other words, the first joining edge 360b and the second joining edge 365b of the second portion 155b are arranged at the respective ends of the second part 265b of the wall 265 facing towards the secant plane B.
One among the joining edge of the first portion 155a and the joining edge of the second portion 155b exhibits a cord adapted for contacting a surface, for example flat, of the joining edge of the other portion.
For example, each joining edge 350a,355a of the first portion 155a comprises a surface 370a, 375a, for example flat, preferably parallel to the secant plane B.
In the preferred embodiment, each surface 370a,375a lies on the secant plane B.
Every surface 370a, 375a delimits an end of the first part 265a of the wall 265. Each joining edge 360b,365b of the second portion 155b comprises a surface 380b,385b, for example flat, preferably parallel to the secant plane B.
Each joining edge 360b,365b of the second portion 155b comprises a cord 390b,395b, for example that rises up from an end of the second part 265b of the wall, adapted for contacting the respective flat surface 370a,375a of the corresponding joining edge 350a,355a of the first portion 155a.
Preferably, each cord 390b,395b rises up from a surface 380b,385b of the respective joining edge 360b,365b of the second portion 155b, for example flat, preferably parallel to the secant plane B.
Every surface 380b,385b delimits an end of the second part 265b of the wall 265.
Each cord 390b,395b of the second portion 155b contacts, for example along the entire longitudinal extension thereof, the surface 370a, 375a of the joining edge 350a,355a of the first portion 155a.
Each cord 390b,395b follows a path that approximates the path P of the duct 160.
In the illustrated embodiment, each cord 390b,395b contacts the respective surface 370a, 375a along a contact surface that has a width, i.e. linear extension along a plane transversal to the duct 160, comprised between 0.2 and 0.8 times the thickness of the wall 265.
Each cord 390b,395b is shaped, at every through hole 230, like a cylindrical wall 400b concentric to the axis of the respective through hole 230.
Each joining edge 350a,355a of the first portion 155a has, at every through hole 230, a cylindrical wall 405a that rises up from a surface 370a, 375a of the respective joining edge 350a,355a of the first portion 155a and is internally concentric to the cylindrical wall 400b of the respective cord 390b,395b of the second portion 155b.
Preferably, the inner surface of every cylindrical wall 405a corresponds to the cylindrical wall of the corresponding through hole 230.
Each joining edge 350a,355a, 360b,365b also comprises a further cord projecting with respect to the corresponding part of the wall 265 in the opposite direction with respect to the duct 160.
The access mouth 240, the withdrawal mouth 245 and the connection mouths 165 are made only in the first portion 155a of the body 155.
In other words, the connection mouths 165, the withdrawal mouth 245 and the access mouth 240 are made in the first part 265a of the wall 265.
The second portion 155b of the body 155 does not have mouths or openings adapted for placing the duct 160 in communication with the outside, i.e. the second portion 265b of wall 265 is continuous along every cross section of the manifold 150.
The first portion 155a has, at the access mouth 240, a portion 410a of the first part 265a of the wall 265 projecting beyond the secant plane B and received in a recessed portion 415b of the second part 265b of the second portion 155b. The joining edges of the first portion 155a and of the second portion 155b follow the profile of the projecting portion 410a and of the recessed portion 415b. In this way, it is possible to make an access mouth of large dimensions with respect to the section of the duct without having to make said access mouth in part in the first portion and in part in the second portion.
Every portion 155a,155b consists of a monoblock made of plastic material, for example by injection molding.
It should be specified that the term monoblock is meant to indicate an object devoid of joining points, i.e. not made by the union of plural parts and in which any section consists of the same body.
Furthermore, the term monoblock body is meant to indicate a body consisting of the solidification of a single volume of a fluid.
The plastic material of which each portion 155a,155b consists can for example be polyethylene, polypropylene or polyamide.
The first portion 155a and the second portion 155b are joined by welding to form the body 155.
For example, the first portion 155a and the second portion 155b are joined by friction welding.
In particular, each cord 390b,395b of the second portion 155b is pressed and simultaneously moved cyclically, i.e. rubbed, against the respective surface 370a, 375a of the joining edge 350a,355a of the first portion 155a until the material is brought into the plastic phase, after which the first portion 155a and the second portion 155b are kept pressed without relative movement between the two parts until the material has cooled down.
The delivery manifold 150 is fixed to the pump 10 through threaded members inserted, through the through holes 230 of every fixing plate 225, in suitable threaded elements, for example nuts, inserted in the corresponding heads 45. The delivery manifold 150 is fixed so that every connection mouth 165 faces onto the outer opening 65 of a respective delivery duct 50.
Moreover, every centering ring 170 is inserted, for example with low clearance, in a seat 175 formed in a respective opening 65 of a delivery duct 50.
In practice, the outer surface 180 of the centering ring 170 is inserted in contact in a matching inner surface 185, for example cylindrical, of the seat 175.
In addition, when the delivery manifold 150 is fixed to the pump 10, the central opening 260 of the outer surface 255 of the body 155 embraces, with substantial clearance, the grooved shank 30 of the shaft 25 and for example, a protective collar of said grooved shank (not illustrated in the figures).
Between every connection mouth 165 of the delivery manifold 150 and every respective pumping chamber 15 an automatic unidirectional valve 195 is arranged, which is housed in a seat 190 formed in a respective delivery duct 50. The invention thus conceived can undergo numerous modifications and variants, and details can be replaced by other technically equivalent elements, as long as they fall within the scope of protection as defined by the following claims.
In practice, the materials used, as well as the contingent shapes and sizes, can be whatever according to the requirements as long as they fall within the scope of protection as defined by the following claims.

Claims

A manifold (70, 150) for a multistage pump (10) provided with a plurality of pumping chambers (15), wherein the manifold (70,150) comprises a body (75,155) which is so shaped as to define a duct (80,160) extending along a path (P) and exhibiting an access mouth (125, 240) and a plurality of connection mouths (85, 165), wherein each connection mouth (85, 165) is adapted to be connected to a corresponding pumping chamber (15) of the pump (10), wherein the body (75, 155) is subdivided into at least a first portion (75a, 155a) and a second portion (75b, 155b) at a secant plane (A, B) parallel to a plane whereon the path (P) is lying, and characterized in that the path (P) is a closed ring path.
The manifold (70, 150) according to claim 1, wherein the path (P) is curved.
The manifold (70,150) according to claim 1, wherein the first portion (75a, 155a) and the second portion (75b, 155b) constitute the entire body (75, 155) of the manifold (70, 150).
The manifold (70, 150) according to claim 1, wherein the first portion (75a, 155a) and the second portion (75b, 155b) of the body (75, 155) are made of a polymeric material.
The manifold (70, 150) according to claim 1, wherein the first portion (75a, 155a) and the second portion (75b, 155b) of the body (75, 155) are made separately by injection molding and joined by welding.
The manifold (70, 150) according to claim 1, wherein the access mouth (125, 240) and the connection mouths (85, 165) are made in the first portion (75a, 155a) of the body (75, 155).
The manifold (70, 150) according to claim 1, wherein the first portion (75a, 155a) comprises a joining edge (270a, 275a, 350a, 355a) adapted to be placed in contact with a corresponding joining edge (300b, 305, 360b, 365b) of the second portion (75b, 155b), and wherein one between the joining edge (270a, 275a, 350a, 355a) of the first portion (75a, 155a) and the joining edge (300b, 305b, 360b, 365b) of the second portion (75b, 155b) exhibits a cord (320b, 325b, 390b, 395b) adapted to contact a flat surface (280a, 285a, 370a, 375a) of the joining edge of the other portion.
A multistage pump (10) comprising a plurality of pumping chambers (15) and a manifold (70) according to any one of the preceding claims, wherein each connection mouth (85,165) is connected to a corresponding pumping chamber (15) of the pump (10).
The pump (10) according to claim 8, comprising an additional manifold (150) according to any one of claims 1 to 7, wherein the second portion (75b) of the manifold (70) is equal to the second portion (155b) of the further manifold (150).