EP3578755B1

EP3578755B1 - Rotary machine

Info

Publication number: EP3578755B1
Application number: EP18382387.1A
Authority: EP
Inventors: Jorge TROBAJO SAN MARTÍN; María VILLANUEVA MADOZ; Ana MAISTERRA MILLO; Francisco Javier SANZ LARRAURI
Original assignee: Entecnia Consulting SLU
Current assignee: Entecnia Consulting SLU
Priority date: 2018-06-04
Filing date: 2018-06-04
Publication date: 2023-06-07
Anticipated expiration: 2038-06-04
Also published as: CN110552882A; EP3578755A1; EP3578755C0; ES2953294T3; CN110552882B

Description

TECHNICAL FIELD

This invention belongs to the field of rotary machines and especially to pumps comprising a rotor with one or more vanes inserted in it, the rotor being contained in a housing where subspaces are created between the vane or vanes and the housing walls and the rotor when the rotor is moved.

STATE OF THE ART

Many applications need pumps, either a vacuum pump for magnifying the effect of a force or any other type of pump. These pumps usually comprise a housing and a rotor housed inside the housing. This rotor comprises one or more slots, so that a vane is at least partially introduced in each one of said slots. The housing houses this rotor, but the inner volume of the housing is greater than the volume occupied by the rotor and the vanes. Thus, when the rotor rotates, the vanes have some space to exit the rotor due to centrifugal force or any other force provided in the pump. This inner volume of the housing is designed such that the vane or vanes go in and out the rotor alternatively, in such a way that the sub-chambers which are created between two consecutive vanes and the corresponding portion of the housing wall and the rotor have a variable volume, depending on the position of the rotor. In the event of one single vane with a single slot, the slot allows the single vane exiting the rotor in two diametrically opposed locations, so that the vane divides the main chamber in different sub-chambers.
Thus, when the rotor rotates, the sub-chambers which are created between two consecutive vanes and the corresponding portion of the chamber wall and rotor have a variable volume, depending on the position of the rotor. A fluid inlet hole located in the chamber wall is in fluid connection with a device where reduction of pressure is desired and feeds the chamber in an inlet point with a compressible fluid, such as air or any other gas. As this inlet point is fixed, but the vanes move with the rotor, this inlet point belongs to different sub-chambers while the rotor rotates. A fluid outlet hole is in turn located in an outlet point of the chamber wall, and is in fluid connection with an outlet fluid zone, such as the atmosphere or a duct belonging to a different device. When the pressure in this outlet point is greater than the pressure in the outlet fluid zone, fluid exits the chamber.
This fluid pressure is different on each time instant, generating pressure waves with a certain frequency and amplitude. As the rotary velocity of the machine is high, these pressure waves cause a significant level of noise.
Particularly, noise at high frequency of 1000Hz or more is considerably unpleasant to human listeners, and generation of such high-frequency noise may cause depreciation of a commercial value of any equipment. For instance, in the automotive industry, product specifications include tight NVH requirements.
Noise reduction devices are known in the art, such as for example WO-2017/067819-A1 , WO-03046384-A1 , WO-14075660-A1 , WO-14075658-A2 , US-4,747,761-A .
In some existing products, the elements to mitigate the level of noise are assembled outside the rotary machine, resulting in an increasing of the installation space.

DESCRIPTION OF THE INVENTION

The invention provides a solution for this problem by means of a noise reduction device according to claim 1. Preferred embodiments of the invention are defined in dependent claims.
A first aspect of the invention relates to a rotary machine comprising

a pump chamber comprising a base, a cover and a lateral wall defining an inner space (the cover and the lateral wall can be a single element, for example a cap shaped element);
a rotor housed (at least partially) in the inner space of the pump chamber. This rotor comprises at least one slot and at least one vane, each vane being at least partially introduced in the at least one slot of the rotor;
an electric motor having a drive shaft passing through a central opening of the base of the pump chamber to drive the rotor;
at least one inlet port for sucking air from a device where the pressure is aimed to be reduced, the inlet port being in fluid communication with at least an inlet hole of the pump chamber. The inlet hole can be placed in the base of the pump chamber or in the cover of the pump chamber;
at least one outlet port in fluid communication with a first outside zone of the rotary machine for discharging compressed air exiting the pump chamber through at least one outlet hole in the pump chamber;
a noise reduction element comprising at least one damping conduct intended to reduce the sound pressure level of the compressed air (the at least one damping conduct comprises at least one inlet opening and at least one outlet opening and allows the passage of fluid but restricting the free passage of sound);
an intermediate chamber between the base of the pump chamber and the motor, the inlet port and the outlet port being connected to this intermediate chamber (the intermediate chamber can comprise an upper base, a lower base and a lateral or perimetrical wall. Preferably the upper base of this intermediate chamber makes up the base of the pump chamber but alternatively the base of the pump chamber can be an additional element mounted over the upper base of the intermediate chamber. Also, in some embodiments the intermediate chamber does not comprise an upper base and the base of the pump chamber makes up the upper base and closes the intermediate chamber. In other embodiments the lower base of the intermediate chamber can be a base of the motor (or a base attached to the motor) such that the intermediate chamber only comprises an upper base and a lateral wall but when coupled with the base of the motor delimits an inner closed space. The inlet port can be connected to the lateral wall of the intermediate chamber.).

According to the invention the rotary machine comprises an intermediate conduct housed at least partially in the intermediate chamber for communicating the inlet port with the at least one inlet hole of the pump chamber. The intermediate conduct leaves a free space inside the intermediate chamber and the noise reduction element is placed at least partially within a part of this free space. The at least one outlet hole of the pump chamber opens into this free space of the intermediate chamber such that the compressed air exiting the pump chamber through the outlet hole enters the damping conduct of the noise reduction element. The outlet hole can be placed preferably in the base of the pump chamber (when the base of the pump chamber is the upper base of the intermediate chamber the outlet hole is placed in the upper base. When the base of the pump chamber is an additional element, the outlet hole is placed in the additional element and the upper base of the intermediate chamber comprises holes or openings in correspondence with the at least one outlet hole to allow the compressed air to pass towards the intermediate chamber).
In some embodiments of the invention the noise reduction element occupies only a part of the free space of the intermediate chamber.
In some embodiments the damping conduct comprises at least one outlet opening which opens to the free space of the intermediate chamber such that at least a part of the compressed air circulating inside the damping conduct discharges into the free space and enters the outlet port for exiting to an outside zone of the rotary machine.
In some embodiments the noise reduction element is configured (and mounted inside the intermediate chamber) such that an inlet opening of the damping conduct faces the outlet hole of the pump chamber providing a connection between the outlet hole and the inlet hole of the damping conduct. In these embodiments the noise reduction element (or at least a part of the noise reduction element) can be place in contact with the base of the pump chamber or upper base of the intermediate chamber. In an alternative embodiment the noise reduction element comprises a protrusion (for example a cylindrical protrusion) surrounding the inlet opening of the damping conduct such that the protrusion connects directly with the outlet hole of the pump chamber. Thus the compressed air enters directly into the inlet opening of the damping conduct without passing through the free space of the intermediate chamber.
In some alternative embodiments the noise reduction element defines an inlet first expansion space in the intermediate chamber in fluid communication with the outlet hole (in the base of the pump chamber or in the upper base of the intermediate chamber). The damping conduct comprises at least an inlet opening placed in this inlet expansion space such that compressed air exiting from the pump chamber, through the outlet hole, opens and expands in the inlet expansion space and at least a part of this air (preferably most of it) enters the damping conduct through the inlet opening and then circulates inside the damping conduct. Preferably the inlet expansion space is a substantially closed space defined between the noise reduction element and interior walls of the intermediate chamber such that the easiest exit way for the compressed air is through the damping conduct.
In some embodiments the noise reduction element comprises at least an outlet opening which opens to the free space of the intermediate chamber such that at least a part of the compressed air circulating inside the damping conduct discharges into the free space and enters the outlet port for exiting to an outside zone of the rotary machine. The damping conduct can comprise several outlet openings.
In some embodiments the noise reduction element defines an outlet expansion space in the intermediate chamber in fluid communication with the outlet port. The damping conduct comprises at least an outlet opening placed in the outlet expansion space such that the compressed air circulating inside the damping conduct discharges into the outlet expansion space and enters the outlet port for exiting to an outside zone of the rotary machine. Preferably the outlet expansion space is a substantially closed space defined between the noise reduction element and interior walls of the intermediate chamber such that the easiest exit way for the compressed air is through the outlet port.
In alternative embodiments the noise reduction element comprises the outlet port such that the damping conduct discharges the compressed air directly to the outside zone without passing through the intermediate chamber.
In some embodiments the noise reduction element comprises a hole orthogonal to the damping conduct such that the compressed air is forced to change abruptly its direction (inside the damping conduct) to improve the noise reduction.
In some embodiments the noise reduction element comprises an internal expansion area with a cross section greater than the cross section of the damping conduct such that the compressed air suffers an expansion inside the damping conduct to improve the noise reduction.
In some embodiments the damping conduct can be a serpentine or labyrinth conduct. The noise reduction element can comprise several walls defining the labyrinth conduct.
In some embodiments the damping conduct (for example part of the walls defining a labyrinth conduct) is mounted or integrated at least partially in the base of the pump chamber or upper base of the intermediate chamber and housed in the intermediate chamber. The damping conduct is placed in a side of this base which is opposite to the pump chamber and faces (and housed in) the intermediate chamber.
In other embodiments the damping conduct (for example part of the walls defining a labyrinth conduct) is mounted or integrated at least partially in the base of the motor. The damping conduct is placed in a side of this base of the motor which is opposite to the motor and faces (and housed in) the intermediate chamber.
In another embodiment a first part of the walls is integrated in the base of the pump chamber or upper base of the intermediate chamber and a second part of the walls is integrated in the base of the motor, for defining a labyrinth path. The first part and second part of the walls defining the labyrinth conduct can also be mounted or attached to the upper base and base of the motor respectively.
The noise reduction element can comprises a noise damping material, for example a plastic material or a foam material.
The rotary machine of the invention comprises several advantages and/or differences compared with previous devices:

The noise reduction system is placed in a free and unused space. This way the incorporation of the noise reduction system to the rotary pump does not implies an increase in the volume needed for mounting the rotary pump.
The noise reduction system is housed inside the intermediate chamber and thus protected from the external environment. That means it is not necessary for the different parts of the system to meet special requirements in materials or geometry for being placed in outside.
The noise reduction of the invention can be designed to be an independent part of the rotary pump (and designed without special requirements derived from the manufacturing of the rotary machine) or can be integrated in the base of the motor or in the intermediate chamber and thus no additional part being required.
The device of the invention permits the optimization of the design of the noise reduction system to every kind of pump, vacuum range, kind of motor and electric voltage or noise frequencies to damp.
The noise reduction system permits the incorporation of different damping solutions such as air expansion, conducts with different section or length, labyrinth conducts or blind conducts.

BRIEF DESCRIPTION OF THE DRAWINGS

To complete the description and in order to provide for a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate an embodiment of the invention, which should not be interpreted as restricting the scope of the invention, but just as an example of how the invention can be carried out.
The drawings comprise the following figures:

Figures 1A, 1B and 1C show perspective views of a rotary pump of the invention.
Figures 2A, 2B, 2C, 2D, 2E, 2F, 2G and 2H show first embodiments of a noise reduction element according to the invention.
Figure 3A and 3B show a second embodiment of a noise reduction element according to the invention.
Figure 4A, 4B and 4C show a third embodiment of a noise reduction element according to the invention.
Figure 5A and 5B show a fourth embodiment of a noise reduction element according to the invention.
Figure 6A, 6B and 6C show a fifth embodiment of a noise reduction element according to the invention.
Figure 7A and 7B show a sixth embodiment of a noise reduction element according to the invention.
Figure 8A, 8B and 8C show a seventh embodiment of a noise reduction element according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Figures 1A, 1B and 1C show a rotary machine according to the invention comprising a pump chamber 1 defined by a base 11 and a cap comprising a cover 12 and a lateral wall 13, the pump chamber 1 housing a rotor 14. This rotor 14 comprises at least one slot 141 and at least one vane 142 being at least partially introduced in the slot 141 of the rotor 14. In figure 1C the lateral wall and cover has been partially removed for clarity.
The rotary machine also comprises an electric motor 2, having a drive shaft 3 to drive the rotor 14, and an intermediate chamber 4 between the base 11 of the pump chamber 1 and the motor 2. In the embodiment shown in the figures the intermediate chamber 4 comprises an upper base which defines the base 11 of the pump chamber 1 and a lateral wall 41, the intermediate chamber 4 being closed by a base 21 of the motor 5. In alternative embodiments (not shown) the base 11 of the pump chamber 1 can be a separate element (for example a sheet or plate) attached or mounted upon the upper wall of the intermediate chamber 4. The base 11 can also make up the upper base of the intermediate chamber.
The rotary machine comprises at least one inlet port 5 for sucking air from another device (not shown). The inlet port 5 is connected to the lateral wall 41 of the intermediate chamber 4 and is in fluid communication with at least an inlet hole 15 of the pump chamber 1, through an intermediate conduct 51 housed at least partially in the intermediate chamber 4. The inlet hole 15 can be placed in the base 11 of the pump chamber 1. In this case the intermediate conduct 51 is completely housed inside the intermediate chamber 4 as represented in figures 1, 2 or 3. The inlet hole can also be placed in the cover 12 of the pump chamber 1 in which case a first part 511 of the intermediate conduct 51 is housed in the intermediate chamber 4 as represented in figures 4, 5, 6, 7 and 8 and a second part (not represented) exists outside the intermediate chamber 4 to connect with the inlet hole 15 of the pump chamber 1.
The rotary machine also comprises at least one outlet port 6 in fluid communication with an outside zone of the rotary machine. This outlet port 6 is connected to this intermediate chamber 4 for discharging compressed air exiting the pump chamber 1 through at least one outlet hole 16 in the upper base of the intermediate chamber 4 which constitutes the base 11 of the pump chamber 1.
The rotary machine comprises also a noise reduction element 7 comprising at least one damping conduct 71 intended to reduce the sound pressure level of the compressed air exiting the pump chamber 1. This noise reduction element 7 is placed in a free space 410 in the intermediate chamber 4, as can be seen for example in figure 1B.
In some embodiments of the invention, as shown in figures 2A, 2B, 2C, 2D, 2E, 2F, 2G and 2H, the noise reduction element 7 occupies only a part of the free space 410 of the intermediate chamber 4. In these embodiments the height of the noise reduction element 7 is substantially equal to the internal space height of the intermediate chamber 4 (the heights are measured in the direction of the rotor axis). In these embodiments the intermediate conduct 51 has been represented completely housed in the intermediate chamber 4, connecting the inlet port 5 with an inlet hole 15 housed in the base 11 of the pump chamber 1. Figures 2A, 2B and 2C show an embodiment of the noise reduction 7 configured to define an inlet expansion space 411 in the intermediate chamber 4, this inlet expansion space 411 being placed in the intermediate chamber 4 such as to be in fluid communication with the outlet hole 16 of the pump chamber 1. Preferably this inlet expansion space 411 is placed beneath and facing the outlet hole 16 such that the outlet hole 16 opens directly in this inlet expansion space 411. The damping conduct 71 of the noise reduction element 7 comprises at least an inlet opening 711 placed in this inlet expansion space 411 such that at least a part the compressed air exiting from the pump chamber 1, through the outlet hole 16, opens and expands in the inlet expansion space 411 and enters the damping conduct 71 through the inlet opening 711 and then circulates inside the damping conduct 71. Preferably the inlet expansion space 411 is a substantially closed space defined between a recess 72 of the noise reduction element 7 and an inner tubular protuberance 42 of the intermediate chamber 4 such that the easiest exit way for the compressed air exiting the pump chamber is through the damping conduct 71.
The noise reduction element 7 comprises a plurality of outlet openings 712 which open to the free space 410 of the intermediate chamber 4 such that the compressed air circulating inside the damping conduct 71 discharges into the free space 410 and enters the outlet port 6 for exiting to an outside zone of the rotary machine.
In some embodiments, as shown in figures 2D, 2E, 2F, 2G and 2H the noise reduction element 7 is configured to define an outlet expansion space 412 in the intermediate chamber 4 in fluid communication with the outlet port 6. Preferably the outlet expansion space 412 is a substantially closed space defined between an external wall of the noise reduction element 7 and an outer protuberance 43 of the intermediate chamber 4, this outlet expansion space 412 being placed over and facing the outlet port 6. The damping conduct 71 comprises at least an outlet opening 713 placed in this outlet expansion space 412 such that a part of the compressed air circulating inside the damping conduct 71 discharges into the outlet expansion space 412 and enters the outlet port 6 for exiting to an outside zone of the rotary machine.
The damping conduct comprises also a plurality of outlet openings 712 opening to the free space 410 of the intermediate chamber 4 such that a part of the compressed air circulating inside the damping conduct 71 discharges into the free space 410 and enters the outlet port 6 for exiting to an outside zone of the rotary machine.
In some embodiments, as shown in figures 2F and 2H, the noise reduction element 7 comprises a vertical hole 714 orthogonal to the damping conduct 71 such that the compressed air is forced to change abruptly its direction (inside the noise reduction element 7) to improve the noise reduction.
In some embodiments the noise reduction element 7 comprises an internal expansion area 715 with a cross section greater than the cross section of the damping conduct 71 such that the compressed air suffers an expansion inside the damping conduct 71 to improve the noise reduction, as shown in figure 2G.
Figures 3A and 3B show another embodiment for the noise reduction 7. In this embodiment the noise reduction element 7 comprises a cylindrical protrusion 73 surrounding the inlet opening 711 of the damping conduct 71 such that the protrusion 73 connects directly with the outlet hole 16 of the pump chamber 1. Thus the height of the noise reduction element 7 can be smaller than the internal space height of the intermediate chamber 4 (the heights are measured in the direction of the rotor axis). In this embodiment the compressed air exiting the pump chamber 1 (through the outlet hole 16) enters directly into the inlet opening 711 of the damping conduct 71 without passing through the free space 410 of the intermediate chamber 4. The damping conduct 71 comprises also a plurality of outlet openings 712 opening to the free space 410 of the intermediate chamber 4 such the compressed air circulating inside the damping conduct 71 discharges into the free space 410 and afterwards enters the outlet port 6 for exiting to an outside zone of the rotary machine.
In an embodiment shown in figures 4A, 4B and 4C the noise reduction element 7 is configured and mounted in the intermediate chamber 4 such that an inlet opening 711 of the damping conduct 71 faces the outlet hole 16 of the pump chamber 1 establishing a connection between the outlet hole 16 and the inlet opening 711 of the damping conduct 71. In this embodiment the noise reduction element 7 (or at least a part of the noise reduction element) can be in contact with the base of the pump chamber 1. In this embodiment the noise reduction element 7 comprises the outlet port 6 such that the damping conduct 71 discharges the compressed air directly to the outside zone without passing through the free space 410 of the intermediate chamber 4 .
Figures 5A and 5B show an embodiment of a noise reduction element 7 which occupies all the free space 410 of the intermediate chamber 4. The noise reduction element 7 is configured and mounted in the intermediate chamber 4 such that an inlet opening 711 of the damping conduct 71 faces the outlet hole 16 of the pump chamber 1 establishing a connection between the outlet hole 16 and the inlet opening 711 of the damping conduct 71. In this embodiment the noise reduction element 7 comprises the outlet port 6 such that the damping conduct 71 discharges the compressed air directly to the outside zone without passing through the free space 410 of the intermediate chamber 4.
In an embodiment shown in figures 6A, 6B and 6C the damping conduct 71 is a labyrinth conduct. The noise reduction element 7 comprises several walls 74 defining the labyrinth conduct. These walls 74 are mounted on the base 21 of the motor 2. Figure 6C shows the path followed by the compressed air between a beginning point 741 of the labyrinth, in communication with the outlet hole 16 of the pump chamber, and a finishing point 742 of the labyrinth in communication with the outlet port 6. In this embodiment the noise reduction element 7 comprises the outlet port 6 such that the damping conduct 71 discharges the compressed air directly to the outside zone without passing through the intermediate chamber 4.
The embodiment shown in figures 7A and 7B shows a noise reduction element 7 comprising several walls 74 defining the labyrinth conduct. These walls 74 are mounted or integrated in the upper wall of the intermediate chamber 4 and housed in the intermediate chamber 4. Figure 7B shows the path followed by the compressed air between a beginning point 741 of the labyrinth, in communication with the outlet hole16 of the pump chamber, and a finishing point 742 of the labyrinth in communication with the outlet port 6. In this embodiment the noise reduction element 7 comprises the outlet port 6 such that the damping conduct 71 discharges the compressed air directly to the outside zone without passing through the intermediate chamber 4.
In the embodiments shown in Figures 8A, 8B and 8C the noise reduction element 7 comprises several walls 74 defining the labyrinth conduct. In this embodiment a first part 743 of the walls is integrated on the upper wall of intermediate chamber 4 and a second part 744 of the walls is integrated on the base 21 of the motor 2. Figure 7B shows the path followed by the compressed air between a beginning point 741 of the labyrinth, in communication with the outlet hole16 of the pump chamber, and a finishing point 742 of the labyrinth in communication with the outlet port 6. In this embodiment the noise reduction element 7 comprises the outlet port 6 such that the damping conduct 71 discharges the compressed air directly to the outside zone without passing through the intermediate chamber 4.
In this text, the term "comprises" and its derivations (such as "comprising", etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc.
The invention is obviously not limited to the specific embodiments described herein, but also encompasses any variations that may be considered by any person skilled in the art (for example, as regards the choice of materials, dimensions, components, configuration, etc.), within the general scope of the invention as defined in the claims.

Claims

A rotary machine comprising
a pump chamber (1) comprising a base (11), a cover (12) and a lateral wall (13) defining an inner space;

a rotor (14) housed in the inner space of the pump chamber (1), this rotor (14) comprising at least one slot (141);

at least one vane (142), each vane (142) being at least partially introduced in one slot (141) of the rotor (14);

an electric motor (2) having a drive shaft (3) passing through a central opening of the base (11) to drive the rotor (14);

at least one inlet port (5) for sucking air form a device where pressure is aimed to be lowered, the inlet port being in fluid communication with at least an inlet hole (15) of the pump chamber (1),

at least one outlet port (6) in fluid communication with an outside zone of the rotary machine for discharging compressed air exiting the pump chamber (1) through at least one outlet hole (16) of the pump chamber (1),

a noise reduction element (7) comprising at least one damping conduct (71) intended to reduce the sound pressure level of the compressed air

an intermediate chamber (4) between the base (11) of the pump chamber (1) and the motor (2), the inlet port (5) and the outlet port (6) being connected to this intermediate chamber (4),
characterized by comprising an intermediate conduct (51) housed at least partially in the intermediate chamber (4) for communicating the inlet port (5) with the at least one inlet hole (15) of the pump chamber, the intermediate conduct (51) leaving a free space (410) in the intermediate chamber (4) and the noise reduction element (7) being placed at least partially within a part of this free space (410), and wherein the at least one outlet hole (16) opens into this free space (410) of the intermediate chamber (4) such that the compressed air exiting the pump chamber (1) through the outlet hole (16) enters the damping conduct (71) of the noise reduction element (7).
- Rotary machine according to claim 1 wherein the noise reduction element (7) comprises at least an outlet opening (712) which opens to the free space (410) of the intermediate chamber (4) such that at least a part of the compressed air circulating inside the damping conduct (71) discharges into the free space (410) and enters the outlet port (6) for exiting to an outside zone of the rotary machine.
- Rotary machine according to any of previous claims wherein the noise reduction element (7) is configured such that an inlet opening (711) of the damping conduct (71) faces the outlet hole (16) of the pump chamber establishing a connection between the outlet hole (16) and the inlet hole (15).
- Rotary machine according to claim 3 wherein the noise reduction element (7) comprises a protrusion (73) surrounding the inlet opening (711) of the damping conduct (71) such that the protrusion connects directly with the outlet hole (16) of the pump chamber (1).
- Rotary machine according to claims 1 or 2 wherein the noise reduction element (7) defines an inlet expansion space (411) in the intermediate chamber (4) in fluid communication with the outlet hole (16) of the pump chamber (1) and wherein the damping conduct (71) comprises at least an inlet opening (711) placed in this inlet expansion space (411) such that compressed air exiting from the pump chamber (1), through the outlet hole (16), opens and expands in the inlet expansion space (411) and at least a part enters the damping conduct (71) through the inlet opening (711) and circulates inside the damping conduct (71).
- Rotary machine according to any of previous claims wherein the noise reduction element (7) defines an outlet expansion space (412) in the intermediate chamber (4) in fluid communication with the outlet port (6) and wherein the damping conduct (71) comprises at least an outlet opening (713) placed in the outlet expansion space (412) such that the compressed air circulating inside the damping conduct (71) discharges into the outlet expansion space (412).
- Rotary machine according to any of previous claims wherein the noise reduction element (7) comprises a hole (714) orthogonal to the damping conduct (71).
- Rotary machine according to any of previous claims wherein the noise reduction element (7) comprises an internal expansion area (715) with a cross section greater than the cross section of the damping conduct (71).
- Rotary machine according to any of claims 1,2,3,4,5,7 or 8 wherein the noise reduction element comprises the outlet port (6).
- Rotary machine according to any of previous claims wherein the damping conduct (71) is mounted or integrated at least partially in the base (11) of the pump chamber (1) or upper base of the intermediate chamber (4) and housed in the intermediate chamber (4)..
- Rotary machine according to any of previous claims wherein the damping conduct (71) is mounted or integrated at least partially in a base (21) of the motor (2).
- Rotary machine according to any of previous claims wherein the damping conduct (71) comprises a serpentine or labyrinth conduct.
- Rotary machine according to claim 12 wherein the noise reduction element (7) can comprise several walls (74) defining the labyrinth conduct.
- Rotary machine according to claim 13 wherein a first part (743) of the walls (74) is integrated in the base (11) of the pump chamber (1) or upper base of the intermediate chamber (4) and housed in the intermediate chamber 4 and a second part (744) of the walls (74) is integrated in the base 21 of the motor 2.
- Rotary machine according to any of previous claims wherein the noise reduction element comprises a noise damping material.