Lightweight impeller for motorized blower for medical ventilator

Abstract

Title of the Invention: Lightweight vane wheel for motorized blower for medical ventilator. The invention relates to a vane wheel (1) for a motorized blower (10) for a medical ventilator (20), comprising a wheel body (2) having a general disc shape with a circular peripheral rim (3) and a central passage (4) with a central opening (4.1) for receiving a drive shaft (11) of an electric motor (12). The wheel body (2) comprises an upper face (2.1) carrying vanes (7) and a lower face (2.2). The upper face (5) has a gradual curvature towards the central opening (4.1) of the central passage (4). The wheel body (2) is configured, on the side of the lower face (2.2), to have longitudinal reinforcing ribs (8) and a three-dimensional reticulated structure (9) located at the center of the lower face (2.2) and traversed by the central passage (4).Motorized blower (10) of a medical ventilator (20) comprising such a bladed wheel (1) and medical ventilator (20) equipped with such a blower (10). Figure in the abstract: Fig. 3.

Description

Title of the invention: Lightweight impeller for motorized blower for medical ventilator

[0001] The invention relates to a lightweight wheel for a medical ventilator blower, a blower equipped with such a wheel and a medical ventilator equipped with such a blower.

[0002] In order to assist certain people, i.e. patients, in their respiratory function, a medical ventilator is used, i.e. a respiratory assistance device, delivering a respiratory gas, such as air, at a non-zero flow rate and / or at a pressure higher than atmospheric pressure (> 1 atm). The air may be supplemented with additional oxygen (i.e. oxygen-enriched air), when the patient must receive, as part of his treatment, a proportion of oxygen greater than 21% by volume.

[0003] Within the medical ventilator, air is generally drawn from the atmosphere, then distributed to the patient by a motorized (micro-)blower, also called a compressor or turbine.

[0004] The air is sucked in by the blower using one (or more) impellers fixed to a rotating shaft or motor shaft driven in rotation by an electric motor. The impeller is rotatable in the wheel compartment of a volute above the electric motor.

[0005] During rotations of the wheel, the flow of aspirated gas, such as air, enters the wheel compartment through a gas inlet and leaves through a gas outlet, typically through an outlet conduit supplying the gas flow to a patient circuit, such as a flexible hose, supplying a respiratory interface, such as a respiratory mask, a tracheal intubation tube or the like, supplying the gas to the patient.

[0006] In general, a vane wheel comprises a solid body, i.e. a wheel body, having a general disc shape, comprising a central opening intended to receive the motor shaft of the electric motor. The vanes or blades of the vane wheel are arranged on the upper face of the wheel body, while its lower face is oriented towards the motor. The vanes comprise structures, such as small walls, arranged radially and spaced from each other, having more or less complex shapes, projecting vertically on the upper face of the wheel.

[0007] The lower face of the wheel body is flat, while its upper face is curved, that is to say it has a progressive curvature towards its center, i.e. towards its central opening. In other words, the wheel body has a thickness which increases substantially from its periphery towards its center.

[0008] EP-A-2165078, EP-A-2102504 and WO-A-2012 / 139681 describe blowers equipped with such solid-body wheels arranged in respiratory assistance devices.

[0009] In practice, this type of solid body wheel poses a balancing problem when it is installed on the motor shaft which carries it, which requires tedious and costly operations of (re-)balancing the wheel of each blower at the end of production.

[0010] If the balancing is poorly executed, the wheel body being solid and its mass (generally called "weight") being able to be quite significant, depending on the dimensions of the wheel considered, one can see the appearance of vibrations during the operation of the wheel, that is to say when it is driven in rotation at high speed by the motor of a blower for a medical ventilator, typically at several thousand revolutions per minute (rpm).

[0011] However, such vibrations can cause noise pollution, reduce aeraulic performance, lead to higher energy consumption and / or premature wear of the blower using this wheel, i.e. a reduction in its longevity.

[0012] In view of this, a problem is to be able to improve the impeller in such a way as to overcome all or part of the aforementioned problems and disadvantages.

[0013] One solution of the invention relates to a vaned wheel comprising a wheel body having a general disc shape comprising a circular peripheral edge and a central passage with a central opening for receiving an electric motor motor shaft, the wheel body comprising an upper face carrying vanes and a lower face opposite the upper face, said upper and lower faces extending between the circular peripheral edge and the central passage, and at least a portion of the upper face having a progressive curvature in the direction of the central opening of the central passage.

[0014] Furthermore, according to the invention, the wheel body is configured, on the lower face side, to have elongated reinforcing ribs and a reticulated three-dimensional structure located in the center of the lower face and crossed by the central passage, that is to say that the wheel body is partially hollowed out on the lower face side so as to no longer have a solid structure, but in particular a lattice structure, i.e. openwork, which gives a reduced mass to the entire wheel.

[0015] Depending on the embodiment considered, the impeller of the invention may comprise one or more of the following characteristics: - part of the elongated reinforcing ribs are formed in the lower face of the wheel body. - the elongated reinforcing ribs extend from the circular peripheral edge towards the three-dimensional reticulated structure. - at least some of the elongated reinforcing ribs are connected to each other to others by joining elements formed in the lower face of the wheel body. the joining elements are arranged perpendicular to the elongated reinforcing ribs. at least a portion of the elongated reinforcing ribs extend from the circular peripheral edge and join to form the reticulated three-dimensional structure the long, straight reinforcing ribs are curved. the three-dimensional reticulated structure forms a spatial lattice The three-dimensional reticulated structure comprises elongated reinforcing ribs arranged in the spatial lattice. the central passage of the wheel is formed of a tubular section or several coaxial tubular sections. a tubular section forming at least part of the central passage of the wheel is arranged in the center of the reticulated three-dimensional structure, in particular in the center of the spatial lattice. the three-dimensional reticulated structure is secured to the underside of the wheel body. the wheel has a mass less than 1.5 g, preferably less than or equal to 1.4 g, more preferably less than or equal to 1.3 g, advantageously between 0.50 and 1.2 g, preferably between 0.75 and 0.90 g. the wheel is made of polymer type PA12, PEEK, ABS or other, or aluminum or one of its alloys. the wheel has a diameter between 30 and 50 mm, preferably between 32 and 40 mm. the fins carried by the upper face of the wheel have a curved shape. the fins are formed of small walls. the vanes extend radially on the upper face of the wheel. the fins extend radially between the circular peripheral edge towards the central passage. the central passage is formed of several coaxial tubular sections. the coaxial tubular sections comprise a lower section arranged in the center of the reticulated three-dimensional structure and an upper section carrying the central orifice. the lower section includes a second central orifice. at least a portion of the upper face of the wheel has a gradual curvature towards the central opening of the central passage, in particular a central region located around the central opening, so as to form a substantially truncated structure with a curved wall projecting upwards.

[0016] The invention also relates to a motorized (micro-)blower for a medical ventilator comprising a bladed wheel according to the invention, carried by the motor shaft of the electric motor of said blower.

[0017] Depending on the embodiment considered, the blower of the invention may comprise one or more of the following characteristics: - the motor shaft passes through the coaxial tubular sections of the impeller, in in particular the lower section arranged in the center of the reticulated three-dimensional structure and the upper section carrying the central orifice. - the impeller is secured, for example glued, to the motor shaft of the blower's electric motor. - the impeller is arranged in the impeller compartment of a volute above the blower motor. - the volute consists of a lower half-volute and an upper half-volute assembled together. - the volute includes an air inlet and an air outlet. - the blower is designed to reach a rotation speed of 25,000 rpm / minute, typically between 500 and 15,000 rpm, for example around 100,000 rpm in certain cases. - the electric motor of the blower is a brushless motor. - the electric motor comprises a rotor and a stator, typically a winding made of conductive wire, like copper wire. - the electric motor includes a casing protecting the rotor and the stator.

[0018] Furthermore, the invention also relates to a medical ventilator comprising a motorized blower according to the invention.

[0019] Depending on the embodiment considered, the medical ventilator of the invention may comprise one or more of the following characteristics: - it includes an air intake circuit through which ambient air enters the fan. - the air intake circuit is in fluid communication with the air inlet of the volute. - the intake circuit comprises air purification means, preferably filtration means, such as a filter. - it includes an air outlet circuit in fluid communication with the fan wheel compartment, in particular via the volute air outlet. - the air outlet of the volute is arranged on a lateral duct in communi-

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027] fluid connection with the air outlet circuit. - the air outlet circuit ends at an outlet port, preferably fitted with an outlet fitting. - a patient circuit comprising one or more gas conduits is fluidically connected to the air outlet circuit, typically to the outlet connector - the patient circuit comprises one or more flexible tubes, supplying a patient respiratory interface (not shown), such as a mask, a tracheal intubation tube or the like. - it includes means of control. - the control means include an electronic card with microprocessors). - the control means are configured to control the blower. - it includes means of electrical supply, such as a rechargeable battery and / or a connection to the mains (110 / 220V). - it includes a rigid carcass or external shell. - the control means, the air intake circuit, the air outlet circuit and the blower are arranged in the rigid casing. - it includes a graphical user interface (GUI). - the IGU includes a display, in particular a touch screen. - the touch screen is in color. - the GUI includes one or more selection keys or buttons, in particular touch keys displayed by the touch screen. The invention will now be better understood thanks to the following detailed description, given for illustrative but non-limiting purposes, with reference to the appended figures among which: [Fig.l] schematically shows a fan impeller for a solid-body medical ventilator according to the prior art. [Fig.2] is a schematic sectional view of a solid body impeller according to the prior art, such as that of [Fig.l]. [Fig.3] is a top view, partially in section, of an embodiment of a partially hollowed-out impeller according to the invention. [Fig.4] is a bottom view, partially in section, of the impeller according to the invention of [Fig.3]. [Fig.5] is a bottom view of the impeller according to the invention of [Fig.3] and [Fig.4], [Fig.6] is a view of the impeller according to the invention of [Fig.3] to [Fig.5]. [Fig.7] shows schematically an embodiment of an electric motor blower equipped with a bladed wheel according to the invention, shown with its volute open, by example the impeller from [Fig.3] to [Fig.6].

[0028] [Fig.8] schematizes the blower of [Fig.7], with its closed volute.

[0029] [Fig.9] schematizes the arrangement in a medical ventilator, of a blower with electric motor equipped with a bladed wheel according to the invention, for example the blower of [Fig.7] and [Fig.8].

[0030] [Fig.l] and [Fig.2] schematically show a bladed wheel 1 with a solid wheel body 2 according to the prior art intended to equip a blower 10 for a medical ventilator 20. The bladed wheel 1 comprises a wheel body 2 having a general disc shape comprising a circular peripheral edge 3 and a central passage 4 for receiving the motor shaft 11 of the (micro-)blower 10, i.e. turbine or compressor, of the medical ventilator 20.

[0031] The wheel body 2 comprises an upper face 2.1 carrying fins 7 and a lower face 2.2 opposite the upper face 2.1. Said upper and lower faces 2.1, 2.2 extend between the circular peripheral edge 3 and the upper opening 4.1 of the central passage 4. The fins 7, also called blades, comprise or are formed from small projecting curved structures carried by the upper face 2.1 of the wheel 1, typically small curved walls, arranged radially and spaced from each other, having more or less complex shapes, projecting vertically on the upper face 2.1 of the wheel body 2. These fins 7 allow the suction of ambient air during the rotations of the wheel 1.Indeed, this type of impeller 1 is intended to be mounted on the motor shaft 11 of an electric motor 12 of a blower 10 for a medical ventilator 20, and rotated at high speed, typically between 500 and 15,000 rpm, or even up to 80,000 rpm or more, during use of the ventilator 20, to suck in ambient air and supply it to a patient, possibly with added oxygen, i.e. air or an air-oxygen mixture.

[0032] At least a portion of the upper face 2.1 having a progressive curvature in the direction of the central opening 4.1 of the central passage 4, in particular the central region 5 situated around the central opening 4.1, so as to form a substantially frustoconical structure 6 with a curved wall projecting upwards, i.e. projecting above the upper face 2.1, and crossed by the central passage 4, i.e. a central protuberance 6 with a curved lateral wall crossed by at least a portion of the central passage 4.

[0033] The wheel body 2 is solid, that is to say it is formed of a “solid” structure, that is to say without recesses or openings, formed of a structural material extending between the upper and lower faces 2.1, 2.2, for example a structure made of polymer material for example PA12, ABS, PEEK or another polymer, or, as the case may be, of aluminum or aluminum alloy.

[0034] Given that the wheel body 2 is solid, its mass, generally of the order of 1.5 g or more, requires balancing the wheel 1 when it is mounted on the motor shaft 11 of the electric motor 12 to avoid vibration or other problems, which is tedious and sometimes complicated, therefore causing a loss of time which negatively impacts the assembly cost.

[0035] Furthermore, during its use, that is to say when it is set in rotation by the electric motor 12 of a blower 10 within a medical ventilator 20, it has been observed, in certain cases, an excess of electricity consumption, aeraulic performances below expectations, or even the appearance of vibrations and noise pollution, which can go as far as premature wear of the blower 10 implementing this wheel 1, that is to say a reduction in its service life.

[0036] In order to attempt to remedy all or part of these problems, according to the invention, the bladed wheel 1 has been modified, in particular lightened thanks to the adoption of an openwork structure of the wheel body 2, that is to say not solid, unlike the wheel 1 of the prior art.

[0037] It should be noted that, for the sake of simplification, the elements in common with the wheel 1 of the prior art of [Fig.l] and [Fig.2], having an identical operation and role, are designated by the same names and the same references below. In other words, only the differences are detailed below in order to avoid unnecessary repetitions and it is sufficient to refer to the above description of [Fig.l] and [Fig.2], to understand their operation and their role in a wheel 1 with blades according to the invention.

[0038] Thus, [Fig.3] to [Fig.6] schematize an embodiment of a bladed wheel 1 according to the invention intended to equip a blower 10 for a medical ventilator 20, which has overall the same structure and the same operation as the wheel 1 of [Fig.1] and [Fig.2], with the exception of the wheel body 2 which is, according to the invention, partially hollowed out, that is to say perforated, in order to reduce its mass but without negatively impacting its performance or causing a reduction in its solidity or resilience over time, i.e. during its use.

[0039] More precisely, to do this, the wheel body 2 has been structured, i.e. configured, on the side of the lower surface 2.2 to have elongated reinforcing ribs 8 and a reticulated three-dimensional structure 9, which is crossed by the central passage 4 which is to receive the motor shaft 11 of the fan 10, as shown in [Fig.7]

[0040] The elongated reinforcing ribs 8 are arranged between the two faces 2.1, 2.2 of the wheel 1, that is to say in the wheel body 2, for example by removing material, or during the manufacture of the wheel 1, for example via an additive manufacturing process from powders or others.

[0041] As can be seen, the elongated reinforcing ribs 8 extend substantially from the circular peripheral edge 3 of the wheel 1 and in the direction of the reticulated three-dimensional structure 9, that is to say towards the central passage 4 of the wheel, on the side of its lower face 2.2. The reticulated three-dimensional structure 9 constitutes a spatial lattice.

[0042] Advantageously, at least a portion of the elongate reinforcing ribs 8 are connected (at 8.1) to each other by joining elements 8.2 carried by the lower face 2.2 of the wheel body 2, as visible in [Fig.4] and [Fig.5]. The elongate reinforcing ribs 8 may have a curved shape, while the joining elements 8.2 may be arranged approximately perpendicular to the elongate reinforcing ribs 8.

[0043] Preferably, the elongated reinforcing ribs 8 extend towards the reticulated three-dimensional structure 9 and at least some of them join to form said reticulated three-dimensional structure 9.

[0044] According to an embodiment visible in [Fig.4] and [Fig.5], the central passage 4 is formed of two coaxial passage sections 4.11, 4.12, namely a lower section 4.12 arranged in the center of the reticulated three-dimensional structure 9 and carrying a second central orifice 4.2, and an upper section 4.11 carrying the central orifice 4.1.

[0045] The motor shaft 11 of the fan 10 is positioned in the lumen, that is to say inside, the two coaxial passage sections 4.11, 4.12, when the wheel 1 is installed on a motor 12 of the fan 10, as shown in [Fig.7].

[0046] It is understood from [Fig.4] and [Fig.5] that the reticulated three-dimensional structure 9 is positioned substantially below the central region 5 located around the upper section 4.11 carrying the central opening 4.1, which forms a substantially frustoconical structure with a curved wall 6 projecting upwards on the side of the upper face 2.1 of the wheel body 2.

[0047] [Fig.7] and [Fig.8] show the impeller 1 of the invention, as illustrated in [Fig.3] to [Fig.6], arranged in the wheel compartment 16 of a motorized blower 10 intended to equip a medical ventilator 20, as shown diagrammatically in [Fig.9].

[0048] More precisely, the impeller 1 is carried by the motor shaft 11 of the electric motor 12 of said blower 10, which electric motor 12 is arranged in a protective casing 12.1 forming a rigid shell containing the elements of the motor, in particular its rotor and stator. Electrical cables 12.2 allow the electrical connection of the motor 12 of the blower 10 not only to an electrical power source, such as a rechargeable battery and / or the mains (110 / 220V), but also to the control means of the medical ventilator 20 which control the operation of the blower 10, for example its accelerations and braking.

[0049] The wheel 1 is arranged in a volute 15 comprising a lower volute 15.2 taken sandwiched between the wheel 1 and the casing 12.1 of the motor 12, and an upper volute 15.1 positioned on the lower volute 15.2, defining between them the wheel compartment 16, within which the impeller 1 is rotatable, when the fan 10 is operating, that is to say when the motor shaft 11 is driven in rotation. Typically, the rotation speed of the wheel 1 is between 500 and 15,000 rpm.

[0050] When the wheel 1 begins to rotate in the wheel compartment 16, the sucked air enters the volute 15, in particular the wheel compartment 16, through an inlet opening or air inlet 13 arranged in the wall of the upper volute 15.1 and the air flow then leaves through a lateral outlet opening or air outlet 14, for example arranged in the wall(s) of the upper volute 15.1 and / or lower volute 15.2. The air outlet 14 is preferably carried by a lateral duct 14.1, as illustrated in [Fig.8], in fluid communication with the wheel compartment 16 to collect and convey the air flow coming from said wheel compartment 16.

[0051] The arrangement of the elongated reinforcing ribs 8 and the reticulated three-dimensional structure 9 on the side of the lower face 2.2 of the wheel body 2 makes it possible to produce a wheel with a partially openwork body, that is to say with a non-solid body, therefore lighter than conventional finned wheels.

[0052] For comparison purposes, a solid body wheel according to the prior art, as in [Fig. 1] and [Fig. 2], and a wheel according to the invention, as in [Fig. 3] to [Fig. 6] were produced with the same material and with the same dimensions, and their respective masses were then compared. The fact of perforating the wheel body 2 by arranging elongated reinforcing ribs 8 and a reticulated three-dimensional structure 9 according to the invention allowed a mass saving of the order of 45%, which makes it possible to avoid all or part of the aforementioned problems existing with the wheels of the prior art.

[0053] In particular, tests carried out with the wheel according to the invention thus obtained have demonstrated a very significant reduction in vibrations, during its operation, despite the fact that the wheel has not undergone balancing, unlike conventional wheels. This is explained in particular by the fact that the reduction in mass leads to a reduction in the amplitude of the “oscillatory” risk during operation of the wheel.

[0054] Advantageously, the wheel 1 of the invention is manufactured by additive manufacturing from polymer powders such as PA12, ABS, PEEK or others.

[0055] [Fig.9] schematizes the arrangement, within a medical ventilator 20, of a blower 10 with electric motor equipped with a bladed wheel 1 according to the invention, for example the blower 10 of [Fig.7] and [Fig.8], arranged in the external rigid casing 20.1 of the medical ventilator 20.

[0056] It is understood that, during its operation, the blower 10 sucks in ambient air which enters the intake circuit 23 of the fan 20, via an air inlet 21, preferably being purified at the inlet by a filter 25 or the like, for example a HEPA type filter. The air then travels through the intake circuit 23 until it reaches the blower 10 due to the rotations of the wheel 1 which generate a suction of air thanks to the vanes 7 of the vaned wheel 1. The air enters the wheel compartment 16, via the air inlet 13 arranged in the wall of the upper volute 15.1, before leaving in the form of an air flow exiting through the air outlet 14 and carried by the lateral duct 14.1 which supplies it to the outlet circuit 24 of the fan 20, which ends at an outlet orifice 22 carried for example by an outlet connector 22.1 or the like, to which is fluidically connected a patient circuit (not shown) comprising one or more gas conduits, such as one or more flexible hoses, supplying a patient respiratory interface (not shown), such as a mask, a tracheal intubation tube or other used to supply the gas to the patient.

[0057] Optionally, during its transit in the fan 20, the air flow can be supplemented with additional oxygen in order to enrich it with oxygen.

[0058] Usually, such a medical ventilator 20 also comprises other conventional elements allowing its operation (not shown here), in particular control means which control the operation of the blower 10, for example an electronic card(s) carrying one or more (micro-)processors implementing algorithms, an electrical power source, such as a rechargeable battery and / or a connection to the mains (110 / 220V), a graphical user interface (GUI)...

Claims

Claims

1. Impeller (1) comprising a wheel body (2) having a general disc shape comprising a circular peripheral edge (3) and a central passage (4) with a central opening (4.1) for receiving a motor shaft (11) of an electric motor (12), the wheel body (2) comprising an upper face (2.1) carrying fins (7) and a lower face (2.2) opposite the upper face (2.1), said upper (2.1) and lower (2.2) faces extending between the circular peripheral edge (3) and the central passage (4), and at least a portion of the upper face (5) having a progressive curvature in the direction of the central opening (4.1) of the central passage (4), characterized in that the wheel body (2) is configured, on the side of the lower face (2.2), to have elongate reinforcing ribs (8) and a reticulated three-dimensional structure (9) located in the center from the lower face (2.2) and crossed by the central passage (4).

2. Wheel according to claim 1, characterized in that a part of the elongated reinforcing ribs (8) are formed in the lower face (2.2) of the wheel body (2).

3. Wheel according to one of the preceding claims, characterized in that the elongated reinforcing ribs (8) extend from the circular peripheral edge (3) towards the three-dimensional reticulated structure (9).

4. Wheel according to one of the preceding claims, characterized in that at least part of the elongated reinforcing ribs (8) are connected to each other by connecting elements (8.1) formed in the lower face (2.2) of the wheel body (2).

5. Wheel according to claim 1, characterized in that the reticulated three-dimensional structure (9) comprises elongated reinforcing ribs (8) arranged in a spatial lattice.

6. Wheel according to claim 1, characterized in that the central passage (4) is formed of several coaxial tubular sections (4.11, 4.12).

7. Wheel according to claim 6, characterized in that the coaxial tubular sections (4.11, 4.12) comprise a lower section (4.12) arranged in the center of the reticulated three-dimensional structure (9) and an upper section (4.11) carrying the central orifice (4.1).

8. Wheel according to one of the preceding claims, characterized in that it has a diameter of between 30 and 50 mm and / or a mass in-

9. less than 1.5 g. Motorized blower (10) for medical ventilator (20) comprising a bladed wheel (1) according to one of the preceding claims, carried by a motor shaft (11) of the electric motor (12) of said blower (10).

10. A medical ventilator (20) comprising a motorized blower (10) according to claim 9.

Images