Vane pump

Abstract

A vane pump (1) for conveying a fluid, comprising:-a housing body (2) defining a suction line (3), a supply line (4) and a housing volume (5) between said suction line (3) and said supply line (4); -a rotor (6) arranged within said housing volume (5) and comprising at least two vanes (7) defining a fluid volume for conveying said fluid; and an assembly (8) of fixing elements interposed between the housing volume (5) and the rotor (6). The vane pump further comprises at least one interference element (9), which is interposed between the housing body (2) and the assembly (8) made of fixing elements and which is at least partially accommodated in the housing body (2) and / or in the assembly (8) made of fixing elements, and the interference element (9) is at least partially accommodated in the suction line (3) and / or in the feed line (4).

Description

Technical Field

[0001] The invention relates to a vane pump. Background Art

[0002] The term "vane pump (or rotary vane pump)" refers to a type of positive displacement pump.

[0003] As with all positive displacement pumps, the flow delivered is always proportional to the speed.

[0004] Rotary vane pumps have different types of vanes: sliding, flexible, oscillating, rotating, and external.

[0005] Vane pumps are known for their dry starting, ease of maintenance and good suction characteristics over the life of the pump.

[0006] Although the configurations vary, most vane pumps operate on the same general principles described below.

[0007] The slotted rotor is supported eccentrically by means of an assembly consisting of fixed elements.

[0008] The rotor is positioned adjacent to the wall of the assembly formed by the fixed elements to form a crescent-shaped cavity.

[0009] The blades fit into recesses in the rotor. As the rotor rotates and fluid enters the pump, centrifugal force, hydraulic pressure, and / or push rods push the blades against the wall of the housing body.

[0010] The housing body defines a suction line, a supply line, and a housing volume therebetween.

[0011] The close fit between the blades, rotor and the assembly consisting of the fixing elements gives this technology good suction characteristics.

[0012] The housing body and the assembly of fixed elements forces the fluid into the supply line through the aperture in the assembly of fixed elements.

[0013] The fluid enters the cavity formed by the assembly consisting of the blades, the rotor and the stationary elements.

[0014] As the rotor continues to turn, the vanes carry the fluid from the mouth of the suction line to the crescent-shaped cavity on the other side, where the fluid is pushed through the discharge hole of the assembly formed by the fixed element.

[0015] The fluid then flows out of the mouth of the supply line.

[0016] Therefore, the overall structure of the vane pump consists of three main elements: the rotating body, the assembly consisting of fixed elements and the housing body.

[0017] As an example of the prior art, US2021 / 095664 shows a vane pump comprising a rotor, a plurality of vanes, a cam ring, a side member in contact with a first end surface of the cam ring, a cover member in contact with a second end surface of the cam ring and attached to the vane pump body itself, and finally a connecting member configured to connect the side member and the cover member on the outer peripheral surface of the cam ring and extend between the side member and the cover member.

[0018] As another example of the prior art, US2022 / 170458 shows a vane pump, which includes a side member, a cover member, a groove formed in the outer peripheral surfaces of the side member and the cover member to extend in the circumferential direction, and a connecting member configured to connect the side member and the cover member; in the vane pump, the connecting element further includes: a first support portion configured to support the side member; a second support portion configured to support the cover member; and an extension portion formed to extend between the first support portion and the second support portion, the extension portion extending in the axial direction of the rotor.

[0019] The prior art with respect to the structures described to date suffers from various motion-related operational problems, in particular undesired rotations.

[0020] One example is the rotation of an assembly consisting of fixed elements, which may occur during assembly / disassembly steps or during normal pump operation steps.

[0021] This rotation causes the opening of the mouth of the suction line and the opening of the mouth of the supply line to be displaced.

[0022] This displacement causes the geometry of the separation between the supply region (high pressure) and the suction region (low pressure) to be partially or completely blocked and to be changed relative to the normally positioned state of the corresponding opening in the housing body.

[0023] The phenomena described lead to blockages and internal leakages and ultimately to a reduction in hydraulic performance for the same mechanical power absorbed.

[0024] Many mechanical elements are provided in the prior art to prevent the mechanical component from rotating in the receiving portion, such as keys, protrusions, threaded elements and friction elements.

[0025] Many of these systems suffer from the disadvantages of being relatively costly and / or relatively large in size.

[0026] The solution usually used for such pumps is to assemble an O-ring with a relatively large cross-section on the assembly consisting of the fixing element. This O-ring is compressed strongly, thus generating considerable friction between the components.

[0027] This friction force reaches a value sufficient to overcome the forces generated within the pump during operation.

[0028] However, the solutions proposed in the existing literature are not entirely convincing.

[0029] In fact, like the other mechanical elements mentioned, O-rings do not protect against assembly errors.

[0030] Additionally, the compression of the O-ring depends on the tolerances of many internal components, causing the friction generated to vary within multiple pumps.

[0031] Therefore, it is not mathematically possible to rule out the possibility of this problem occurring again.

[0032] Another recurring problem is the possibility of rotation of one component relative to the other components of an assembly consisting of fixed elements.

[0033] One example is that the front disc may rotate relative to the rear disc, with consequences similar to those described above regarding the overall performance of the pump.

[0034] To prevent one component from rotating relative to another, a small longitudinal "pin" is often used which, once inserted, prevents relative movement.

[0035] Pins seem to be a solution suitable for solving the stated problem, but pins present a critical problem during the assembly step. In fact, due to the small size of the pins, they can easily fall or be misplaced, thereby hindering the assembly operation. Summary of the invention

[0036] The technical task of the present invention is to provide a vane pump which can overcome the shortcomings existing in the prior art.

[0037] It is therefore an object of the present invention to provide a vane pump in which the inner component is prevented from rotating in one or both directions relative to the outer housing body.

[0038] Therefore, another object of the present invention is to provide a vane pump which prevents internal components of the pump from relative rotation and mutual misalignment.

[0039] Furthermore, it is an object of the invention to provide a vane pump which is simple and safe to assemble.

[0040] Finally, it is therefore an object of the present invention to provide a vane pump whose elements which prevent the undesired misalignment discussed above are inexpensive and small in size.

[0041] These technical tasks and purposes described in detail are basically achieved by vane pumps.

[0042] Other features and advantages of the invention will become more apparent from the following illustrative and therefore non-limiting description of an embodiment of a vane pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The description will be set forth below with reference to the accompanying drawings, provided for illustration purposes only and therefore not limiting, in which:

[0044] - Figure 1 is a schematic illustration of an exploded view of an embodiment of a rotary vane pump entity of the present invention;

[0045] - Figure 2 and Figure 3 is a schematic perspective view of a first possible embodiment of a rotary vane pump entity of the present invention;

[0046] - Figure 4 and Figure 5 is a schematic perspective view of a second possible embodiment of a rotary vane pump entity of the present invention;

[0047] - Figure 6 and Figure 7 It is a schematic perspective view of a third possible embodiment of a rotary vane pump entity of the present invention. DETAILED DESCRIPTION

[0048] With reference to the accompanying drawings, a rotary vane pump is generally referred to as a vane pump 1 .

[0049] A vane pump 1 for conveying a fluid comprises a housing body 2 which defines a suction line 3 , a supply line 4 and a housing volume 5 between the two mentioned elements, ie the housing volume 5 is in communication with the suction line 3 and the supply line 4 .

[0050] The vane pump 1 is further provided with a rotor 6 which is arranged in a stator 23 and comprises at least two vanes 7 , which in turn is arranged in the housing volume 5 .

[0051] Between two consecutive blades 7 a fluid volume is defined.

[0052] The blade 7 may be an elongated body, the ends of which together with the ends of other blades 7 define elements contacting other fixed parts, thus defining the above-mentioned fluid volume.

[0053] Alternatively, the blade 7 may refer to a single end of the elongated body.

[0054] In other words, the blade 7 may refer to any element that rotates together with the rotor 6 and defines a fluid volume suitable for conveying a fluid.

[0055] The rotor 6 is preferably provided with a plurality of blades 7 to define at least two fluid volumes.

[0056] The rotor 6 , which generally consists of a shaft, then moves an impeller provided with blades 7 in order to convey the fluid from the suction line 3 to the supply line 4 .

[0057] The assembly 8 of fixed elements (of which the stator 23 is a part) is interposed between the housing volume 5 and the rotor 6 to define a cavity in which the rotor 6 can rotate. Specifically, the assembly 8 of fixed elements defines a cavity in which the blades 7 can rotate.

[0058] Preferably, the assembly 8 of fixing elements comprises three fixing elements, as depicted in the figures. Alternatively, the assembly 8 of fixing elements may comprise two fixing elements or more than three fixing elements.

[0059] The vane pump 1 may also have mechanical sealing elements 22 suitable for maintaining a stable hydraulic seal, such as keys, projections and fixing elements.

[0060] Preferably, an O-ring is used as a mechanical sealing element to achieve a static hydraulic sealing function. A mechanical seal 22 is usually used to prevent hydraulic leakage between the housing body 2 and the handle of the rotor 6 during dynamic connection.

[0061] The vane pump 1 has at least one interference element 9 which is located between the housing body 2 and the assembly 8 of fixing elements and which is at least partially accommodated in one of the two aforementioned elements.

[0062] The interference element 9 which is the subject of the invention consists of one or more elements made of any material.

[0063] Preferably, the interference element 9 is made of stainless steel.

[0064] The interference element 9 is designed to be mounted in the housing volume 5 so as to be accommodated in the housing body 2 and / or in an assembly consisting of fixing elements.

[0065] Preferably, the interference element 9 is accommodated in a compartment of the suction line 3 and / or the supply line 4 of the vane pump 1 , if the interference element 9 is at least partially accommodated in the housing body 2 .

[0066] Preferably, the interference element 9 is at least partially accommodated in the suction line 3 and / or in the supply line 4 .

[0067] Even more preferably, the housing volume 5 defines at least one first housing seat 10 in which the interference element 9 is at least partially housed.

[0068] According to another possible embodiment of the invention, the interference element 9 is housed in an assembly 8 consisting of fixing elements and engages with a compartment of the suction line 3 and / or of the supply line 4 .

[0069] Preferably, the assembly 8 of fixing elements defines at least one second receptacle 11 in which the interference element 9 is at least partially received.

[0070] The interference element 9 , in conjunction with a suitable receiving geometry in the assembly 8 consisting of the fixing element, performs a dual function on the vane pump 1 after installation and assembly.

[0071] In fact, the interference element 9 simultaneously fulfils two functions, namely aligning the fixing elements of the assembly of fixing elements 8 and holding the assembly of fixing elements 8 in place within the housing volume 5 .

[0072] Advantageously, these two functions can be achieved without the need for high friction forces generated by O-rings or other mechanical sealing elements 22 having only a hydraulic sealing function.

[0073] Preferably, the interference element 9 is installed both in the compartment of the suction line 3 and / or the supply line 4 and in the assembly 8 consisting of fixing elements.

[0074] The interference element 9 may be dimensioned such that it remains permanently coupled to the compartment of the suction line 3 and / or the supply line 4 due to its elasticity.

[0075] Alternatively, the interference element 9 can also be dimensioned such that, due to its own elasticity, it remains fixedly coupled with a suitable geometry formed in the fixing element of the assembly 8 consisting of fixing elements.

[0076] Both configurations disclosed do not increase the complexity of the assembly / disassembly operations of the vane pump 1, since the positions defined by the fixing element and / or the suction line 3 and the supply line 4 make it possible to easily insert the interference element 9. In other words, the assembly complexity of the vane pump 1 of the present invention is not increased compared to the assembly of the vane pump 1 existing in the prior art.

[0077] Thus, the addition of the interference element 9 provides the vane pump 1 with additional technical operating characteristics and safety features, without affecting the aspects of the essential elements mentioned in the prior art.

[0078] According to a possible embodiment, the interference element 9 is made in the form of a shaped spring 12 comprising two end portions 13 and a central portion 14 defined between the two end portions 13 .

[0079] The interference element 9 in the form of a molded spring 12 is shaped so as to be able to engage with the suction line 3 or the supply line 4 and to abut against the assembly 8 consisting of the fixing element.

[0080] The formed spring 12 is slightly deformed when the vane pump 1 is assembled and is assembled in place as described above to prevent the components in the vane pump 1 from being misaligned and rotated.

[0081] Preferably, the two ends 13 of the interference element 9 in the form of a shaped spring 12 are shaped so as to be able to engage in the first housing seat 10 , while the central portion 14 adopts a position and shape so as to be able to abut against the second housing seat 11 .

[0082] Advantageously, the shaped spring 12 (interference element 9 ) does not in any way hinder the disassembly operation which can be achieved by performing the assembly operation in reverse.

[0083] According to another possible embodiment of the interference element 9 , the shaped spring 12 is a flat spring 15 .

[0084] Preferably, the interference elements 9 in the form of flat springs 15 are usually used in pairs, e.g. Figure 4 , which shows two flat springs 15 mounted so as to abut against different parts of the compartment defined by the supply line 4 .

[0085] Advantageously, the assembly of the flat spring 15 is further simplified by the fact that it is not preloaded or deformed in any way during assembly.

[0086] Once in place, the flat spring 15 forms a projection, thereby preventing the assembly 8 consisting of the fixing element from undesired or excessive rotation within the housing volume 5 of the vane pump 1 .

[0087] The alignment of the fixing element 8 is ensured by the geometrical coupling with the pair of flat springs 15, whether the pair of flat springs is in a deformed state or in a relaxed state.

[0088] In fact, the flat springs 15 are deformed during insertion and only return to their original dimensions when they enter a recess in the suction line 3 or in the supply line 4 .

[0089] According to a third possible embodiment, the interference element 9 has a first portion 16 , the shape of which matches the shape of the second receiving seat 11 .

[0090] The interference element 9 is inserted into the second housing seat 11 and has a second portion 17 opposite to the first portion 16 and adapted to abut against the first housing seat 10 .

[0091] The last embodiment of the proposed interference element 9 has at least two bodies 18 (hereinafter referred to as parallel bodies 18) extending parallel to the rotation axis 19 of the rotor 6 and two arcs 20 connecting the parallel bodies 18 by the ends. In other words, the arcs 20 extend along the outer surface of the assembly 8 consisting of the fixing elements (i.e., along the surface where they are placed in the second housing 11) to connect the two parallel bodies 18. Therefore, in the event of a possible misalignment, one parallel body 18 transmits the movement to the other parallel body 18 through the arc 20 abutting on one end of the housing 11 to prevent the various components of the vane pump 1 from being misaligned.

[0092] In addition, if Figure 6 As shown in , the interference element 9 comprises at least two bodies 21 extending radially with respect to the axis of rotation 19 from two connecting arcs 20 , ie according to parallel bodies 18 .

[0093] In other words, the proposed interference element 9 has a design with two "stops" connected by other rods, the task of which is to make the interference element 9 solid, so as to constitute a single piece.

[0094] In the last-described configuration, the inside of the housing body 2 of the vane pump 1 and the outside of the assembly 8 consisting of fixing elements are provided with special recesses, into which the interference elements 9 in the form of “detents” are inserted.

[0095] After the interference element 9 has been mounted in the assembly, any relative rotational movement between the housing body 2 of the vane pump 1 and the assembly 8 consisting of the fixing element is completely blocked.

[0096] The fixing elements are thus kept perfectly aligned with one another and correctly positioned relative to the housing body 2 of the vane pump 1 .

[0097] The interference element 9 is highly visible after assembly, allowing careful inspection for correct assembly.

[0098] Preferably, the interference element 9 may be made in a shape different from the above-described shape, but having similar elements, in order to prevent undesired misalignment of the components of the vane pump 1 .

[0099] Advantageously, the operations required to assemble the interference element 9 that is the subject of the present invention are facilitated and simplified.

[0100] Advantageously, the interference element 9 has a simple geometry, making it easy to manufacture and thus cost-effective.

[0101] Advantageously, in the present invention, the other mechanical sealing elements of the vane pump 1 now serve only the hydraulic sealing function and can therefore be modified and simplified quite easily.

Claims

1. A vane pump (1) for conveying a fluid, comprising: - a housing body (2) defining a suction line (3), a supply line (4) and a housing volume (5) between the suction line (3) and the supply line (4); a rotor (6) arranged in the housing volume (5) and comprising at least two blades (7), a plurality of blades (7) defining a fluid volume for conveying the fluid from the suction line (3) to the supply line (4); as well as - an assembly (8) consisting of fixed elements interposed between the housing volume (5) and the rotor (6) so as to define a cavity (6) in which the rotor rotates, It is characterized in that - the vane pump further comprises at least one interference element (9) which is interposed between the housing body (2) and the assembly (8) of fixed elements and is at least partially accommodated in the housing body (2) and / or in the assembly (8) of fixed elements; and The interference element (9) is at least partially accommodated in the suction line (3) and / or in the supply line (4).

2. The vane pump (1) according to claim 1 or 2, wherein: The housing volume (5) defines at least one first housing seat (10), and wherein the interference element (9) is at least partially housed in the first housing seat (10).

3. The vane pump (1) according to claim 1 or 2, wherein: The assembly (8) of fixing elements defines at least one second housing seat (11), and wherein the interference element (9) is at least partially housed in the second housing seat (11).

4. Vane pump (1) according to one or more of the preceding claims, wherein: The interference element (9) is made in the form of a shaped spring (12), which includes: two end portions (13) shaped to engage in the suction line (3) or in the supply line (4); and a central portion (14) defined between the two end portions (13) and shaped to abut the assembly (8) consisting of the fixing element.

5. The vane pump (1) according to claim 5 when dependent on claims 3 and 4, wherein: The two end portions (13) of the interference element (9) are shaped to engage in the first housing seat (10), and the central portion (14) is shaped to abut against the second housing seat (11).

6. The vane pump (1) according to claim 5 or 6, wherein: The shaped spring (12) is a flat spring (15).

7. The vane pump (1) according to claim 3 and 4, wherein: The interference element (9) has: a first portion (16), the first portion is shaped to be complementary to the second receiving seat (11), and the first portion is inserted into the second receiving seat (11); and a second portion (17), the second portion being opposite to the first portion (16) and being designed to abut against the first receiving seat (10).

8. The vane pump (1) according to claim 8, wherein: The first part (16) of the interference element (9) has at least two bodies (18) parallel to the rotation axis (19) of the rotor (6) and two arc-shaped portions (20) connecting the parallel multiple bodies (18), and wherein the second part (17) includes at least two bodies (21) extending radially from the connecting arc-shaped portions (20) relative to the rotation axis (19).

9. Vane pump (1) according to one or more of the preceding claims, wherein: The assembly (8) consisting of fixing elements has a mechanical sealing element (22) with a hydraulic sealing function.

10. The vane pump (1) according to claim 10, wherein: The mechanical sealing element (22) is an O-ring.

11. Vane pump (1) according to one or more of the preceding claims, wherein: The interference element (9) is made of stainless steel.

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