AU2013377427A1

AU2013377427A1 - Turbine for a breathing assistance apparatus with improved gas tightness

Info

Publication number: AU2013377427A1
Application number: AU2013377427A
Authority: AU
Inventors: Pierre-Emmanuel DUBOIS
Original assignee: Air Liquide Medical Systems SA
Current assignee: Air Liquide Medical Systems SA
Priority date: 2013-02-11
Filing date: 2013-12-18
Publication date: 2015-09-10
Also published as: EP2954213B1; FR3002008B1; CN104981614A; WO2014122368A1; CA2899157A1; FR3002008A1; CN104981614B; ES2620026T3; EP2954213A1

Abstract

A turbine for a breathing assistance apparatus with improved gas tightness. Abstract: The invention concerns a turbine for a breathing assistance apparatus comprising an electric motor (1) cooperating with a vaned rotor (2) to generate a gas stream, and a volute (3, 4) comprising a lower volute portion (3) and an upper volute portion (4) with a gas inlet passage (5), which couple together and are shaped so as to form an internal compartment in which the vaned rotor (2) is disposed, and in which the lower volute portion (3) comprises a first peripheral rim (3a) and the upper volute portion (4) comprises a second peripheral rim (4a), said first peripheral rim (3a) and second peripheral rim (4a) facing each other when the lower volute portion (3) is coupled to the upper volute portion (4). At least one structure made from an elastomeric material is arranged between or around at least a portion of the peripheral rims (3a, 4a) of the two volute portions (3, 4). A breathing assistance apparatus equipped with a turbine according to the invention. Figure

Description

WO 2014/122368 1 PCT/FR2013/053158 Turbine for a breathing assistance apparatus with improved gas tightness The invention relates to a micro-fan or turbine 5 intended to equip a respiratory assistance apparatus. More specifically, the invention relates to improvements to the sealing of the aeraulic part, which means to say the volute. 10 Certain breathing assistance apparatuses use microfans or turbines which serve to generate a pressurized gas, generally air or oxygen-enriched air, which is then sent to the airways of a patient. 15 A turbine of this type is notably described in document. EP-A-2102504 which teaches a breathing assistance apparatus allowing a regulated delivery of a gas, notably air, by means of a turbine comprising a casing, an air supply duct delimited by the casing, a volute 20 the inlet opening of which is in communication with the air supply duct, an impeller, situated immediately downstream of the volute inlet opening, and a drive motor rotating the impeller so as to generate a centrifugal stream of air in the volute. 25 The volute is therefore the compartment within which the impeller used to generate the stream of gas sent to the patient is arranged. For production reasons, it is very difficult, or even near-impossible at this time, 30 to create the entire shape of the volute in one single same component. The turbine volute is therefore generally formed of two parts which couple together, namely a volute upper part 35 also referred to as an upper volute and a volute lower part also referred to as a lower volute. The two volute parts are secured together by bonding the two volutes together.

WO 2014/122368 PCT/FR2013/053158 -2 When use is made of an unshrouded impeller, the upper volute needs to be positioned accurately with respect to the impeller in order to guarantee microfan 5 performance. Now, the large number of parts involved in the assembly creates a string of dimensions that does not allow the lower volute to be positioned accurately with respect to the impeller and an uncontrolled clearance is therefore created between the two volute 10 parts at the time of coupling thereof. Bonding the two volute parts together does not allow this clearance to be filled perfectly and problems with sealing result. In other words, the uncontrolled 15 clearance there is between the two volute parts after they have been bonded together gives rise to problems of leakage and gastightness. The problem that therefore arises is that of creating 20 an improved seal between the volute parts even though the spacing between these parts is not mastered, so as to eliminate or minimize problems of leaks and gasti ghtness. 25 The solution is therefore a turbine for a respiratory assistance apparatus comprising an electric motor collaborating with an impeller to generate a stream of gas, and a volute comprising a volute lower part and a volute upper part with a gas inlet passage, which are 30 coupled to one another and shaped in such a way as to form an internal compartment in which the impeller is arranged, and in which the volute lower part comprises a first peripheral rim and the volute upper part comprises a 35 second peripheral rim, said first peripheral rim and second peripheral rim facing one another when the volute lower part is coupled to the volute upper part, characterized in that at least one structure made of WO 2014/122368 PCT/FR2013/053158 elastomeric material is arranged, particularly mounted as a tight fit, between or around at least part of the peripheral rims of the two volute parts, the structure made of elastomeric material comprising a first portion 5 of annular or semi-annular shape, and the structure made of elastomeric material comprising a second portion of tubular shape comprising a central passage. In fact, the structure made of elastomeric material 10 arranged along the peripheral rims of the two volute parts allows not only mechanical retention and correct positioning of the volutes but also good gastightness, even at the duct for discharging gas from the turbine. 15 Depending on circumstances, the turbine of the invention may comprise one or more of the following technical features: - The elastomeric material is a rubber, a silicone or a thermoplastic elastomer. 20 - The second portion of tubular shape connects to the first portion of annular or semi-annular shape. - The volute lower part and the volute upper part 25 are configured to define at least part of a discharge duct used to discharge the gas delivered by the impeller within the compartment comprising said impeller, the second portion of tubular shape being positioned in continuity with said gas discharge duct. 30 - The structure made of elastomeric material, the volute lower part and the volute upper part are secured to one another by adhesive bonding or using the elastomeric component itself . 35 - The volute lower part and the volute upper part are made of polymeric material, particularly of WO 2014/122368 PCT/FR20 1 3/053158 thermoplastic, for example of the PC, ABS, ABS/PC, etc. type. The motor is able to drive the impeller at a speed 5 of between 0 and 100 000 rpm, typically of between 10 000 and 60 000 rpm. - The first portion of annular or semi-annular shape, and the second portion of tubular shape are 10 formed of a single piece. The first portion of annular or semi-annular shape, and the second portion of tubular shape form a single piece obtained by molding. 1M The invention also relates to a respiratory assistance apparatus comprising a turbine according to the invention. 20 The present invention will now be described in greater detail ;with reference to the attached figures among which: figures 1 and 2 depict a schematic (side) view of 25 one embodiment of a microfan or turbine for a breathing assistance apparatus according to the invention, before the elastomeric structure is fitted; figure 3 shows a schematic (side) view of one 30 embodiment of a microfan or turbine for a breathing assistance apparatus after the elastomeric structure according to the present invention has been fitted; and -- figure 4 depicts one embodiment of the elastomeric 35 structure according to the present invention. Figures 1 and 2 schematically depict one embodiment of a motorized microfan or turbine equipping a breathing WO 2014/122368 PCT/FR2013/053158 assistance apparatus comprising an electric motor 1, situated in a housing and via its rotary shaft 6 driving an impeller 2 used to generate a stream of gas, typically a stream of air. 5 The impeller 2 is situated in a three-dimensional structure 3, 4 referred to as a "volute" comprising a volute lower part 3, commonly referred to as the lower volute, and a volute upper part 4 referred to as the 10 upper volute, which connect together. The volute lower and upper parts 3, 4 thus between them define an internal space or internal compartment encompassing the impeller 2, which means to say that 15 the impeller 2 is sandwiched in the internal compartment formed between the volute lower and upper parts 3, 4. The volute lower and upper parts 3, 4 are also shaped 20 to define at least part of a discharge duct 7 used to convey the gas delivered by the said impeller 2. Air is drawn in by the impeller 2 through an inlet opening 5 situated at the center of the volute upper 25 part 4 through which the air drawn in by the impeller 2 situated immediately downstream of the volute inlet opening 5 passes. However, as an alternative, the air inlet can also be via an inlet opening situated laterally in the volute 4. 30 The air is then discharged by the impeller 2 via the gas discharge duct 7 in the form of a centrifugal stream of air generated by the rotation of the impeller 2 when it is driven by the motor 1., then the gas is 35 carried as far as the patient. The volute upper 4 and lower 3 parts are of spiral shaped overall cross section which means to say that WO 2014/122368 PCT/FR2013/053158 -6 their shape evolves in a regular and constantly positive (convex) manner. The volute lower part 3 has the overall shape of a cup 5 the bottom of which comprises a central opening that forms a sleeve around part of the wall or external housing of the motor 1 or of a compartment containing the motor 1 when the volute lower part 3 is positioned around said motor 1 as illustrated in figure 1. A seal 10 (not visible) provides gastightness between the bottom of the volute lower part 3 and the external wall or housing of the motor I or of the compartment containing the motor 1. 15 In figure 1, the volute upper part 4 has been uncoupled from the volute lower part 3 in order to allow the internal compartment containing the turbine 2 and the shaft 6 thereof that drives it in rotation to be seen. 20 Conversely, in figure 2, the volute upper part 4 is depicted in the position in which it is coupled to the volute lower part 3, which means to say that the two volute parts 3, 4 are in contact with one another along a near-circular parting line 8 situated at the 25 peripheral rims 3a, 4a of said volute parts 3, 4 that come into contact with one another. In other words, the parting line 8 defined by the rims 3a, 4a of said volute parts 3, 4 in contact with one 30 another form an almost annulus which is interrupted at the gas discharge duct 7. The turbine of figures 1 and 2 is therefore depicted before the fitting of the elastomeric structure. 35 In order to join the two volute parts 3, 4 together it is commonplace to bond them together along this parting line 8, i.e. to bond together the peripheral rims 3a, WO 2014/122368 PCT/FR2013/053158 4a but that does not produce a sealed connection because there is always an uncontrolled clearance between the peripheral rims 3a, 4a of the two volute parts after they have been bonded together, which 5 clearance gives rise to problems of leaks and gastightness. To overcome these, as illustrated in figure 3, according to the present invention, an elastomeric 10 component 9 of annular or semi-annular shape is inserted between the peripheral rims 3a, 4a of the two volute parts 3, 4. The elastomeric material is chosen in order notably to 15 meet the following requirements: suitable flexibility that will allow sufficient deformation to allow it to be stretched into shape, 20 - resistance to the temperature caused by aeraulic heating, and - that the mechanical elasticity properties be maintained over time because the component is subjected 25 to constant stretching. For example, by way of elastomeric material, it is possible to select rubber, silicone a thermoplastic elastomer TPE, etc. 30 In fact, the elastomeric component 9 fits tightly around the two volutes 3, 4. The tensioning of the elastomeric component 9 thus ensures natural clamping onto the assembly made up of the lower 3 and upper 4 35 volutes at the peripheral rims 3A, 4A. The elasticity properties of the material are used to provide sealing and maintain position.

WO 2014/122368 PCT/FR2013/053158 According to one embodiment illustrated in figure 4, the elastomeric component or structure 9 comprises a first portion 9a in the overall shape of an annulus or near-annulus, which means to say which is annular or 5 semi-annular. Typically, this annulus-shaped or near annulus-shaped portion 9a has a thickness E of between 0.5 and 3 mm, a width L of between 4 and 20 mm and a diameter D of between 45 and 100 mm. 10 Furthermore, the elastomeric component or structure 9 comprises a second portion 9b that connects to the first portion 9a, and these portions 9a, 9b are preferably formed as a single piece, for example obtained by molding or the like. 1-5 The second portion 9b is of tubular shape 10 and comprises a central passage 11 able to carry the gas from the compartment in which the turbine 2 is housed. 20 In fact, this second portion 9b of tubular shape 10 becomes positioned, at least in part, in the continuation of the gas discharge duct 7 receiving the stream of air created by the impeller 2, as depicted n figure 3. Stated differently, the wall of the discharge 25 duct 7 is extended by the second portion 9b of tubular shape 10 of the elastomeric structure or component 9. The inlet to the duct 9b is compressed against the outlet of the duct 7 because the duct 9b forms one 30 single piece with the elastomer 9a gripping tightly around the volute assembly 3, 4. It is therefore the same principle that provides sealing between the two volutes and between the ducts 7 and 9b. 35 The gas, which in general means the air, accelerated by the impeller 2 is recovered by the conveying duct 7 formed in the two volute parts 3, 4 as visible in the figures, and the tubular portion 9b of the elastomeric WO 2014/122368 PCT/FR2013/053158 component or structure 9, and is then sent to a breathing circuit connected to a patient. A turbine according to the invention can be used to 5 treat respiratory problems of all kinds, particularly sleep apnea, COPD, ALS, problems associated with obesity, etc. Typically, a turbine according to the invention is 10 arranged in a breathing assistance apparatus of CPAP (constant pressure) or BiPAP (two pressure levels) type which supplies a patient with respiratory gas by means of a flexible gas supply duct and a patient interface such as a breathing mask or nasal goggles. Mi:

Claims

1. A turbine for a respiratory assistance apparatus 5 comprising: - an electric motor (1) collaborating with an impeller (2) to generate a stream of gas, and - a volute (3, 4) comprising a volute lower part (3) and a volute upper part (4) with a gas inlet 10 passage (5), which are coupled to one another and shaped in such a way as to form an internal compartment in which the impeller (2) is arranged, and in which the volute lower part (3) comprises a first peripheral rim (3a) and the volute upper 15 part (4) comprises a second peripheral rim (4a) , said first peripheral rim (3a) and second peripheral rim (4a) facing one another when the volute lower part (3) is coupled to the volute upper part (4), 20 characterized in that at least one structure (9) made of elastomeric material is arranged between or around at least part of the peripheral rims (3a, 4a) of the two volute parts (3, 4), the structure (9) made of elastomeric material 25 comprising a first portion (9a) of annular or semi-annular shape, and a second portion (9b) of tubular shape (10) comprising a central passage (11). 30

2. The turbine as claimed in the preceding claim, characterized in that the elastomeric material is a rubber, a silicone or a thermoplastic elastomer.

3. The turbine as claimed in one of the preceding 35 claims, characterized in that the second portion (9b) of tubular shape (10) connects to the first portion (9a) of annular or semi-annular shape. WO 2014/122368 PCT/FR2013 /053 158 - 11

4. The turbine as claimed in one of the preceding claims, characterized in that the first portion (9a) of annular or semi-annular shape, and the second portion (9b) of tubular shape (10) are 5 formed of a single piece.

S. The turbine as claimed in one of the preceding claims, characterized in that the first portion (9a) of annular or semi-annular shape, and the 10 second portion (9b) of tubular shape (10) form a single piece obtained by molding.

6. The turbine as claimed in one of the preceding claims, characterized in that the volute lower 15 part (3) and the volute upper part (4) are confiigured to define at least part of a discharge duct (7) used to discharge the gas delivered by the impeller (2) within the compartment comprising said impeller (2) , the second portion (9b) of 20 tubular shape (10) being positioned in continuity with said gas discharge duct (7).

7. The turbine as claimed in one of the preceding claims, characterized in that the structure (9) 25 made of elastomeric material, the volute lower part (3) and the volute upper part (4) are secured to one another.

8. The turbine as claimed in one of the preceding 30 claims, characterized in that the volute lower part (3) and the volute upper part (4) are made of polymeric material, particularly of thermoplastic.

9. The turbine as claimed in one of the preceding 35 claims, characterized in that the volute lower part (3) and the volute upper part (4) are made of thermoplastic. WO 2014/122368 PCT/FR2013/053158 - 12 -

10. The turbine as claimed in one of the preceding claims, characterized in that the motor is able to drive the impeller (2) at a speed of between 0 and 100 000 rpm, typically of between 10 000 and 5 60 000 rpm.

11. A respiratory assistance apparatus comprising a turbine as claimed in one of the preceding claims.