FAN UNIT FOR A VENTILATOR

Description

[0001] The present invention relates to a fan unit for a ventilator, in particular a fan unit with a housing and a fan wheel rotatably mounted in the housing, with which a fluid can be sucked in through an inlet channel of the housing and then expelled again through an outlet channel of the housing.

[0002] Such fan units for ventilators for the ventilation of individuals, particularly those with inadequate or suspended natural breathing, are known in various designs. For example, EP 2 947 328 A1 describes a fan unit with an electric motor, an impeller driven by the motor, and a housing accommodating the impeller and the electric motor. The previously known fan unit is a free-intake fan unit, meaning it has no intake port on the intake side, so that the breathing gas is not sucked in via a hose connected to the fan unit on the intake side. This free-intake fan unit can, for example, be accommodated in a blower box of the ventilator. US 2017 / 0130723 A1 discloses a fan unit for air conditioning systems designed as a drum rotor.

[0003] Against this background, the present invention is based on the object of providing a fan unit for a ventilator that has improved operating performance and relates to a free-intake fan unit and also to a non-free-intake fan unit. In particular, a fluid, for example a breathing gas, sucked into the housing on the suction side by means of the fan wheel should be able to flow out of the housing again on the pressure side at a predetermined pressure. The discharge pressure of the fan unit should achieve higher values ​​than the discharge pressure of conventional fan units for ventilators at the same fan wheel speed, or the speed of the fan unit should be reducible compared to conventional fan units at the same discharge pressure of the fan unit.

[0004] This object is achieved by a fan unit having the features of claim 1. Further, particularly advantageous embodiments of the invention are disclosed in the subclaims.

[0005] It should be noted that the features listed individually in the claims can be combined with one another in any technically reasonable manner and demonstrate further embodiments of the invention. The description further characterizes and specifies the invention, particularly in conjunction with the figures.

[0006] The invention is defined by the appended claims.

[0007] According to the invention, a fan unit for ventilators for ventilating, for example, persons with insufficient or suspended natural breathing comprises a housing with a suction nozzle, wherein the suction nozzle forms an inlet channel for the suction-side inflow of a fluid, for example a respiratory gas, into the housing. The housing further comprises a pressure nozzle which forms an outlet channel for the pressure-side outflow of the fluid from the housing. Furthermore, the fan unit according to the invention comprises a fan wheel rotatably mounted in the housing. This fan wheel is designed and arranged to suck in the fluid via the suction nozzle by rotation and to convey it through the inlet channel into the housing and then to expel the fluid again via the pressure nozzle and to convey it out of the housing through the outlet channel.It should be understood that the rotation of the fan wheel can be driven by a motor, preferably an electric motor, for example, but is not limited to this. Manually driven rotation of the fan wheel is also conceivable.

[0008] The intake port has an inner surface facing the inlet channel. In other words, the inner surface of the intake port defines the inlet channel radially outward. Thus, the inner surface of the intake port defines a nominal inlet channel diameter. According to the invention, the intake port has at least one flow guide element on its inner surface, which defines an inlet channel inner diameter that differs from the nominal inlet channel diameter. A difference in size between the two channel diameters is to be understood as such that it certainly does not fall within the manufacturing-related tolerance range of an intake port, but rather is the result of targeted action.Manufacturing-related size deviations of the two aforementioned channel diameters, which lie within the conventional manufacturing tolerances specified for the manufacture of the intake manifold, are therefore not suitable to justify a size difference between the nominal inlet channel diameter and the inner inlet channel diameter within the meaning of the invention.

[0009] In contrast to the smooth, flat inner surface of a conventional intake port, the intake port of the fan unit according to the invention therefore does not have a flat inner surface. Rather, the inner surface of the intake port according to the invention is structured by the at least one flow guide element, whereby the flow of the sucked-in fluid, for example, a gas or respiratory gas, can be influenced, i.e., controlled, in a manner corresponding to the contour of the flow guide element. The areas of the inner surface of the intake port that are not provided with the flow guide element and that determine the nominal inlet duct diameter can also be smooth and flat, but are not necessarily limited to this.

[0010] In particular, simply by providing at least one flow guide element for locally altering the nominal inlet duct diameter, an increase in the pressure of the fluid sucked in by the fan impeller can be achieved. This, in turn, enables an increase in the pressure of the fluid flowing out on the pressure side, while the speed of the fan impeller of the fan unit according to the invention remains constant compared to conventional fan units. Alternatively, while the fluid pressure in the outlet duct of the pressure port remains constant compared to conventional fan units, the speed of the fan impeller in the fan unit according to the invention can also be reduced. This can improve the operating efficiency of the fan unit according to the invention; by reducing the speed, the smooth running of the fan impeller can be increased, and vibrations, mechanical wear, e.g., on fan impeller bearings, and noise generation of the fan unit can be reduced.

[0011] The fan unit according to the invention is not a free-intake fan unit due to the suction nozzle provided on the suction side, which is separated from the housing as such by an elongated extension forming the inlet channel and can, for example, protrude from the actual outer contour of the housing or protrude from it. Rather, the suction nozzle can be connected to a hose through which the fluid is sucked into the inlet channel.

[0012] The housing of the fan unit disclosed herein can be a substantially closed housing unit that surrounds the fan impeller such that the fluid flow as described herein—namely, the intake of fluid on the suction side of the fan unit and the discharge of fluid on the pressure side of the fan unit—can be generated by the rotation of the fan impeller, in particular with a fluid pressure that is higher than that on the suction side. A motor driving the fan impeller, if provided, for example, an electric motor, can also be accommodated in the housing. However, this is not mandatory.

[0013] The cross-sectional area of ​​the inlet channel may have a round shape, e.g., circular, elliptical, and the like. It may also have an angular shape, e.g., rectangular, square, trapezoidal, generally polygonal, and the like.

[0014] According to an advantageous embodiment of the invention, the flow guide element is a rib (also referred to herein as a fin, web, lamella, and the like) protruding from the inner surface of the intake port. In other words, the rib protrudes radially inward from the inner surface into the inlet channel. Accordingly, the rib reduces the locally defined inlet channel inner diameter compared to the nominal inlet channel diameter defined by the regions of the inner surface not provided with the rib. The inlet channel inner diameter is defined by the distance between a front side of the rib protruding furthest inward into the inlet channel in the radial direction and the boundary surface delimiting the inlet channel diametrically opposite.This boundary surface can be the inner surface of the suction nozzle which determines the nominal inlet channel diameter, but it can also be a surface of another flow guide element which is diametrically opposite the first-mentioned rib.

[0015] According to a further advantageous embodiment of the invention, the flow guide element is a groove formed in the inner surface of the intake port. The groove, which represents a recess formed in the inner surface radially outward, accordingly locally increases the inlet channel inner diameter compared to the nominal inlet channel diameter defined by the regions of the inner surface not provided with the groove. The inlet channel inner diameter is defined here by the distance in the radial direction between a groove base located further outward in the radial direction and a boundary surface delimiting the inlet channel diametrically opposite. This boundary surface can be the inner surface of the intake port that determines the nominal inlet channel diameter, but it can also be a surface of another flow guide element that is diametrically opposite the first-mentioned groove.

[0016] The flow guide element, designed as a groove or rib, enables a different, targeted influence on the fluid flow, particularly pressure increase, in the inlet channel due to the local reduction or enlargement of the channel's inner diameter compared to the nominal inlet channel diameter. It has been found that a flow guide element designed as a groove influences the pressure characteristic of the fluid flow more strongly than a flow guide element designed as a rib.

[0017] According to a further advantageous embodiment, several flow guide elements are arranged equidistantly, i.e., at equal distances from one another, over the circumference of the inner surface of the intake port. The total number of flow guide elements arranged circumferentially on the inner surface allows the fluid flow and thus the fluid pressure, in particular a pressure increase, in the inlet channel to be further specifically influenced.

[0018] A further advantageous embodiment of the invention provides that, when providing a plurality of ribs circumferentially distributed on the inner surface of the intake port as flow guide elements, these ribs extend radially up to the central axis (also referred to herein as the axis of symmetry) of the intake port and are in contact with one another there. They can be materially connected to one another at their contact point in the inlet channel, although this is not absolutely necessary. In other words, viewed in the cross-section of the intake port, the ribs form at least one web that completely crosses the inlet channel in the radial direction (in the case of two diametrically arranged and touching ribs) or a star-shaped arrangement (in the case of three, four, five or more distributed ribs).It should be noted that in the present embodiment with ribs touching each other on the central axis, the inlet duct inner diameter determined by these ribs, which is reduced in comparison to the nominal inlet duct diameter, assumes its absolute minimum value, namely the value zero.

[0019] According to yet another advantageous embodiment of the invention, the flow guide element extends in its longitudinal direction parallel to the central axis of the suction nozzle. In other words, the flow guide element is aligned in its longitudinal direction parallel to the central axis of the suction nozzle. This allows the pressure change, in particular the pressure increase, of the fluid flowing through the suction nozzle caused by the flow guide element to be achieved particularly effectively.

[0020] According to another advantageous embodiment of the invention, the flow guide element extends in its longitudinal direction at an angle to the central axis of the intake port, thus not axially parallel to the central axis. Depending on the angle of inclination of the longitudinal extension of the flow guide element, the resulting pressure increase in the intake channel can be controlled very precisely, in particular, it can be specifically attenuated as desired compared to the axially parallel arrangement.

[0021] According to a further preferred embodiment of the invention, the aforementioned angle or angle of inclination of the longitudinal extent of the flow guide element relative to the central axis of the intake port or inlet channel is greater than 0° and less than or equal to 45°. It should be understood that, in this embodiment, the longitudinal extension direction of the flow guide element, within the meaning of the invention, still extends primarily in the direction of the central axis of the intake port. Furthermore, it should be understood that, depending on the definition of the angle of inclination relative to the central axis of the intake port, the angular range less than 0° to greater than or equal to -45° is to be regarded as equivalent to the above-specified angular range greater than 0° and less than or equal to 45°.

[0022] According to a further advantageous embodiment of the invention, the ratio of the inlet channel inner diameter to the inlet channel nominal diameter is between 0.6 and 1.4, preferably between 0.7 and 1.3, even more preferably between 0.75 and 1.25. It has been found that the desired pressure changes in the inlet channel of the intake port can be achieved most effectively with these ratios. It should be understood that a ratio of the inlet channel inner diameter to the inlet channel nominal diameter of less than one can be achieved by providing at least one rib- / web-shaped flow guide element, and a ratio of the inlet channel inner diameter to the inlet channel nominal diameter of greater than one can be achieved by providing at least one groove-shaped flow guide element.

[0023] Furthermore, according to one embodiment, the fan unit is preferably a radial fan unit, i.e. the fluid is sucked in by the fan wheel in its axial direction and expelled in its radial direction.

[0024] In some embodiments of the invention, the fan wheel of the fan unit has a plurality of blade elements, wherein the blade elements are at least partially each equipped with a winglet extending at least partially on at least one axial longitudinal side of the blade element.

[0025] In some embodiments of the invention, the winglet has an extension of 1° to 20° of the circumference of the fan wheel.

[0026] In some embodiments of the invention, the extension of the winglet increases from the radial inside of the fan wheel to the radial outside of the fan wheel.

[0027] In some embodiments of the invention, the fan wheel is equipped with at least one disc on only one axial side and the disc is arranged only on that axial side which is opposite an axial side of the fan wheel equipped with the winglets.

[0028] Further features and advantages of the invention will become apparent from the following description of non-limiting embodiments of the invention, which are explained in more detail below with reference to the drawings. In this drawing, schematically show: Fig. 1 is an exploded view of an embodiment of a fan unit according to the invention, Fig. 2 is a partial perspective view of the fan unit from Fig. 1 , Fig. 3 a perspective partial view of another embodiment of a fan unit according to the invention, Fig. 4(a)-(c) a perspective detailed view of a suction nozzle of the fan unit from Fig. 2 , a perspective detailed view of a suction nozzle of a further embodiment of a fan unit according to the invention and a perspective detailed view of a suction nozzle of a still further embodiment of a fan unit according to the invention, Fig. 5 a cross-sectional view through the suction nozzle of the fan unit from Fig. 2 and Fig. 6a pressure diagram comparing the fan unit from Fig. 2 with a fan unit according to the prior art. Fig. 7 shows a perspective view of an embodiment of a fan unit. Fig. 8 shows a perspective view of a fan wheel.

[0029] In the different figures, parts that are equivalent in terms of their function are always provided with the same reference symbols, so that they are usually only described once.

[0030] Fig. 1 shows an exploded perspective view of an embodiment of a fan unit 1 according to the invention. The fan unit 1 can particularly preferably be used in a ventilator (not further shown) for ventilating people. As in Fig. 1 As can be seen, the fan unit 1 shown has a housing 2 with a suction nozzle 3, which forms an inlet channel 4 for the suction-side inflow of a fluid, in particular a breathing gas, into the housing 2. Furthermore, the fan unit 1 or the housing 2 has a pressure nozzle 5, which forms an outlet channel 6 for the pressure-side outflow of the fluid from the housing 2. Furthermore, Fig. 1 It can be seen that the fan unit 1 has a fan wheel 7 which is rotatably mounted in the housing 2 and which, by rotation, sucks in the fluid via the suction nozzle 3 and conveys it through the inlet channel 4 into the housing 2 and then expels the fluid again via the pressure nozzle 5 and conveys it out of the housing through the outlet channel 6. For this purpose, the fan wheel 7 is essentially completely accommodated in the housing 2. The rotation is Fig. 1 In the embodiment of the fan unit 1 shown, the drive is effected via a drive motor 8, in particular an electric motor 8, although this is not absolutely necessary. Furthermore, the electric motor 8 can also be accommodated essentially entirely within the housing 2 or can be arranged only partially or entirely outside the housing 2 and connected in a driving manner to the fan wheel 7. Fig. 1 As can also be seen, the fan unit 1 is a radial fan unit, i.e. the fan wheel 7 is arranged in the housing 2 in such a way that the fluid is sucked in via the suction nozzle 3 in the axial direction of the fan wheel 7 and is expelled in the radial direction. The axial direction of the fan wheel 7 falls in the Fig. 1 illustrated fan unit 1 with the central axis 9 of the fan unit 1 or the suction nozzle 3, but is not limited thereto.

[0031] Furthermore, Fig. 1 It can be seen that the suction nozzle 3 on its inner surface facing the inlet channel 4, which has a nominal inlet channel diameter DN (see Fig. 5 ) defines or determines at least one, in this case several, flow guide elements 10. In the Fig. 1 In the fan unit 1 shown, the flow guide elements 10 are designed as grooves. The flow guide elements 10 or grooves 10 define an inlet duct inner diameter DI that deviates from the inlet duct nominal diameter DN, i.e., in this case, is larger than the inlet duct nominal diameter DN. The plurality of grooves 10 are arranged equidistantly distributed over the circumference of the inner surface of the suction nozzle 3, as shown in Fig. 1 can be clearly seen.

[0032] Fig. 2 shows a partial perspective view of the fan unit 1 with the housing 2 Fig. 1 represents.

[0033] Fig. 3 for comparison with fan unit 1 Fig. 2 a perspective partial view of another embodiment of a fan unit 20 according to the invention. In contrast to the fan unit 1 from Fig. 2 In a suction nozzle 21 of the fan unit 20, several flow guide elements 22 are designed as ribs 22 projecting from the inner surface of the suction nozzle 21. Overall, in the Fig. 3 In the embodiment of the fan unit 20 shown, four such ribs 22 are shown, without being limited to this number. The flow guide elements 22 or ribs 22 define an inlet duct inner diameter DI that differs from the inlet duct nominal diameter DN, i.e., in the present fan unit 20, is smaller than the inlet duct nominal diameter DN. The (in this case four) ribs 22 are arranged equidistantly distributed over the circumference of the inner surface of the suction nozzle 21, as in Fig. 3 can be clearly seen. Since the ribs 22 of the fan unit 20 do not extend radially to the center axis 9 of the intake port 21 and accordingly do not contact one another there, the inlet duct inner diameter DI defined by the ribs 22 of the fan unit 20 is greater than zero.

[0034] Fig. 4 shows a perspective detailed view (a) of the suction nozzle 3 of the fan unit 1 Fig. 2 , furthermore a perspective detailed view (b) of a suction nozzle 23 of a further embodiment of a fan unit according to the invention (not shown in detail) and a perspective detailed view (c) of a suction nozzle 24 of yet another embodiment of a fan unit according to the invention, also not shown in detail. The fan units, each having the suction nozzles 23 and 24, not shown here, can be identical to the fan unit 1 from Fig. 1 be constructed.

[0035] The suction nozzle 3 of the fan unit 1 is Fig. 4(a) It can be clearly seen that the flow guide elements 10, designed as grooves, extend parallel to the central axis 9 of the intake port 3 in their respective longitudinal directions, thus running parallel to the axis. This design has proven particularly efficient in achieving the greatest possible pressure increase for the fluid flowing in the inlet channel 4. The flow guide elements can have a straight course in their respective longitudinal directions.

[0036] The suction nozzle 23 from Fig. 4(b) Although it also has flow guide elements 25 designed as grooves, these do not run axially parallel to the central axis 9 in their longitudinal directions, but are inclined at an angle relative to the central axis 9 of the suction nozzle 23. The angle of inclination of the grooves 25 relative to the central axis 9 is preferably more than 0° (0° corresponds to an axially parallel orientation) and less than or equal to 45°. The flow guide elements can have a curved or kinked course in their respective longitudinal directions. The flowing fluid can experience an impulse or swirl due to the curved or kinked course of the flow guide elements.

[0037] At the suction nozzle 24 in Fig. 4(c) the flow guide elements 26, which are again designed as grooves, are also aligned at an angle to the central axis 9, in comparison to the grooves 25 of the suction nozzle 23 from Fig. 4(b) However, it is tilted in exactly the opposite direction. Accordingly, in this configuration, a preferred angle of inclination can be defined as an angle between less than 0° and greater than or equal to -45°C.

[0038] Fig. 5 shows a cross-sectional view through the suction nozzle 3 of the fan unit 1 from Fig. 2 . It is clear in Fig. 5 The nominal inlet duct diameter DN defined by the inner surface of the suction nozzle 3 can be seen. The flow guide elements 10 in the form of grooves incorporated into the inner surface define an inlet duct inner diameter DI, which in the case of the suction nozzle 10 of the fan unit 1 is Fig. 2 is larger than the nominal inlet channel diameter DN and is limited by the groove base 11 of the respective groove 10. Furthermore, in the cross-sectional view of the Fig. 5 a width B of one of the flow guide elements 10, i.e. its extension in the tangential direction of the suction nozzle 3, which is in this case hollow-cylindrical in shape, or of its inner surface, is indicated. The width B of the flow guide element 10 represents a groove width B of the grooves 10 in the embodiment shown. It should be understood that the width of the flow guide element 22 in the case of the Fig. 3 The width of the fan unit 20 shown can also be understood as a web or rib width. The flow element width accordingly generally represents the direction of extension of the respective flow guide elements 10, 22, 25, 26 in the tangential direction of the respective intake ports 3, 21, 23, and 24, respectively.

[0039] It has been found that when the flow guide elements are designed as grooves, as in the case of the axially parallel grooves 10 of the fan unit 1, a maximum pressure gain or pressure increase in the inlet duct 4 can be achieved at a constant speed of the fan wheel 7 compared to conventional suction nozzles without flow guide elements, if a total of 13 axially parallel grooves 10 are provided, distributed equidistantly along the inner circumference of the inner surface of the suction nozzle 3, each with a width B of 0.3 to 2.1 mm, preferably 0.5 to 1.5 mm, for example 0.8 to 1.2 mm. According to the invention, the width B is always adapted in proportion to the number of grooves or ribs. According to the invention, the relationship of the total width B of the ribs (for example 8 ribs of 1 mm) to the free diameter of the inlet duct is 8 mm to 16 mm, orThe ratio of inflow channel area to blocked area by the ribs is preferably in the range 1.1 to 1.6, for example 1.2 - 1.4 or approx. 1.2.

[0040] The diameter ratio of the inlet channel inner diameter DI to the inlet channel nominal diameter DN is 1.05 to 1.6, preferably 1.1 to 1.4, particularly preferably 1.2 to 1.3.

[0041] In the case of flow guide elements designed as ribs, such as the one shown in Fig. 3 shown fan unit 20, a maximum pressure gain in the inlet duct 4 can be achieved with a total of 8 ribs 22 distributed equidistantly in the circumferential direction along the inner surface of the suction nozzle 21.

[0042] In general, the ribs 22 could take any imaginable shape.

[0043] The end face 22a of the ribs is, for example, rounded on the side facing the inflowing fluid.

[0044] The ribs can be square and / or rounded at the inlet and outlet of the fluid.

[0045] The ribs can taper from the inlet to the outlet of the fluid (or vice versa) and thus have a width B.

[0046] The ribs can be symmetrically profiled like airfoils.

[0047] The ribs can be designed as a curved wing.

[0048] The ribs can be designed with notches over the axial length.

[0049] The fins can be designed with openings / holes in the fins, so that an exchange flow is created from one fin flow channel to the next.

[0050] Fig. 6 shows a pressure diagram comparing the fan unit 1 from Fig. 2 with a fan unit according to the prior art, wherein the fan unit 1 as described above and in Fig. 5 shown 13 has axially parallel grooves 10 as flow guiding elements, evenly distributed on the inner surface of the suction nozzle 3.

[0051] The pressure Δp / Δp opt normalized to an optimal operating point of the prior art fan unit (not shown here), i.e., a fan unit with an intake nozzle without flow guide elements according to the invention, is plotted along the ordinate of the pressure diagram. The volume flow Q / Q opt normalized to an optimal operating point of the prior art fan unit is plotted along the abscissa. A pressure curve of the conventional prior art fan unit is plotted in the pressure diagram as a dashed curve 27, and a pressure curve of the fan unit 1 according to an exemplary embodiment of the invention disclosed herein is plotted as a solid curve 28.

[0052] In Fig. 6 It can be clearly seen that at Q / Q opt = 1.0, the optimal pressure Δp / Δp opt (also equal to 1.0) of the conventional fan unit (curve 27) is achieved. In contrast, curve 28 of the fan unit 1 according to the exemplary embodiment of the invention described herein achieves a significantly higher pressure at the same volume flow (= same speed of the fan impeller 7), accordingly Δp / Δp opt > 1.0, in this case approximately Δp / Δp opt = 1.1. Thus, simply by providing the flow guide elements 10 in the inlet channel 4, an increase in fluid pressure can be achieved at the same speed of the fan impeller 7.

[0053] The fan unit according to the invention disclosed herein is not limited to the embodiments disclosed herein, but also encompasses other equivalent embodiments resulting from technically expedient further combinations of the features of the fan unit described herein. In particular, the features and feature combinations mentioned above in the general description and the description of the figures and / or shown alone in the figures can be used not only in the respective combinations explicitly stated herein, but also in other combinations or on their own, without departing from the scope of the present invention. The invention is defined by the appended claims.

[0054] In a preferred embodiment, the fan unit according to the invention is used to operate ventilators for ventilating persons, for example persons with insufficient or suspended natural breathing, in that a fluid, in particular a breathing gas, is conveyed by means of the fan unit, that is to say is sucked in on the suction side and released again on the pressure side at a predetermined pressure, and is then supplied to the person using the ventilator.

[0055] Fig. 7 shows flow guide elements designed as ribs, such as those shown in Fig. 3 shown fan unit 20, a maximum pressure gain in the inlet duct 4 can be achieved with a total of 2 - 30 ribs 22 arranged equidistantly in the circumferential direction along the inner surface of the suction nozzle 21.

[0056] In general, the ribs 22 could take any imaginable shape.

[0057] The end face 22a of the ribs is, for example, rounded on the side facing the inflowing fluid.

[0058] The ribs can be square and / or rounded at the inlet and outlet of the fluid.

[0059] The ribs can taper from the inlet to the outlet of the fluid (or vice versa) and thus have a width B.

[0060] The ribs can be symmetrically profiled like airfoils.

[0061] The ribs can be designed as a curved wing.

[0062] The ribs can be designed with notches over the axial length.

[0063] The fins can be designed with openings / holes in the fins, so that an exchange flow is created from one fin flow channel to the next.

[0064] The statements of the Fig. 7 are also transferable to grooves.

[0065] In general, the flow guide elements could take any imaginable shape.

[0066] The end face 22a of the flow guide elements is, for example, rounded on the side facing the inflowing fluid.

[0067] The flow guide elements can be square and / or rounded at the inlet and outlet of the fluid.

[0068] The flow guide elements can taper from the inlet to the outlet of the fluid (or vice versa) and thus have a width B.

[0069] The flow guide elements can have a symmetrical airfoil profile.

[0070] The flow guide elements can be designed as a curved wing.

[0071] The flow guide elements can be designed with notches over the axial length.

[0072] The flow guide elements can be designed with openings / holes in the flow guide elements so that an exchange flow is created from one flow channel to the next.

[0073] The Figur 8 shows a fan wheel 7 in a perspective view. The fan wheel 7 is equipped with a plurality of blade elements 29 and a disk 32 designed as a support disk 33, as well as a hub 37 for connection to a drive shaft. The blade elements 29 are attached to the support disk 33 and preferably also to the hub 37, and are connected thereto, for example, in one piece. The fan wheel 7 can also be designed without disks 32 and in particular without a support disk 33, for example, as a star-shaped fan wheel.

[0074] The preferred direction of rotation of the fan wheel 7 is illustrated here by an arrow. The blade elements 29 have a suction side 38 and a pressure side 39. The direction of rotation of the fan wheel 7 shown here results in the orientation of the suction side 38 and pressure side 39 shown here.

[0075] In order to effectively and reliably prevent the exchange flow from the side chamber and from the pressure side 39 to the suction side 38 in the direction of the side chamber or an axial side, the fan wheel 7 is equipped with winglets 31. Here, each blade element 29 is equipped with a winglet 31. The winglets 31 each run along an axial longitudinal side 30 of the blade element 29. In the embodiment of the invention shown here, the winglets 31 point in the direction of the suction side 38 of the respective blade element 29. For such a fan wheel 7, both a beneficial pressure increase and a considerable increase in efficiency could be observed.

[0076] The fan wheel 7 shown here, for example, is integrated into the fan unit 1 in such a way that air is sucked in axially and blown out radially. The intake side is located on the axial side 36 with the winglets 31.

[0077] In the embodiment shown here, the fan wheel 7 is equipped with the disc 32 only on one axial side 34. The disc 32, designed as a support disc 33, is arranged on the axial side 34 of the fan wheel 7 opposite the axial side 36 of the fan wheel 7 equipped with the winglets 31.

[0078] In a further development, a disk 32, not shown in detail here, designed as a cover disk 35 can also be provided. The cover disk 35 can be arranged in addition to the support disk 33 on the axial side 36 or can replace the support disk 33. Bezugszeichenliste

[0079] 1 Fan unit 2 Housing 3 Suction nozzle 4 Inlet duct 5 Pressure nozzle 6 Outlet duct 7 Fan wheel 8 Drive motor 9 Center axis 10 Flow guide element / groove 20 Fan unit 21 Suction nozzle 22 Flow guide element / rib 23 Suction nozzle 24 Suction nozzle 25 Flow guide element / groove 26 Flow guide element / groove 27 Pressure curve of a fan unit according to the state of the art 28 Pressure curve of 1 29 Blade element 30 Long side 31 Winglet 32 ​​Disc 33 Support disc 34 Side 35 Cover disc 36 Side 37 Hub 38 Suction side 39 Pressure side B Width of a flow guide element DI Inlet duct inner diameter DN Inlet duct nominal diameter Δp pressure Δp opt Pressure at optimum operating point a fan unit according to the state of the art QVolume flow Q opt Volume flow at optimal operating point of a fan unit according to the state of the art

Claims

1. A ventilation unit for a ventilator for operating the ventilator to ventilate patients, having a housing (2) with a suction port (3, 21, 23, 24) that forms an inlet channel (4) for suction-side inflow of a fluid into the housing (2), and a pressure port (5) that forms an outlet channel (6) for pressure-side outflow of the fluid from the housing (2), and a fan wheel (7) which is rotatably mounted in the housing (2) and which is designed and arranged to take in the fluid via the suction port (3, 21, 23, 24) due to rotation and convey it through the inlet channel (4) into the housing (2) and to expel the fluid again via the pressure port (5) and to convey it out of the housing (2) through the outlet channel (6), characterized in that the suction port (3, 21, 23, 24), on its inner surface that faces the inlet channel (4) and determines an inlet channel nominal diameter (DN), has at least one flow-guiding element (10, 22, 25, 26), by means of which an inlet channel inner diameter (D1) deviating at least in portions from the inlet channel nominal diameter (DN) is established such that a pressure increase of the fluid taken in by the fan wheel (7) is achieved.

2. The ventilation unit according to claim 1, characterized in that the diameter ratio of the inlet channel inner diameter (D1) to the inlet channel nominal diameter (DN) is 1.05 to 1.6, preferably 1.1 to 1.4, particularly preferably 1.2 to 1.3.

3. The ventilation unit according to claim 1, characterized in that the flow-guiding element (10, 25, 26) is a groove which is introduced into the inner surface and which enlarges the inlet channel inner diameter (D1) with respect to the inlet channel nominal diameter (DN).

4. The ventilation unit according to claim 1 or 2, characterized in that the flow-guiding element (22) is a rib which protrudes from the inner surface and which decreases the inlet channel inner diameter (D1) with respect to the inlet channel nominal diameter (DN).

5. The ventilation unit according to one of the preceding claims, characterized in that multiple flow-guiding elements (10, 22, 25, 26) are arranged so as to be distributed equidistantly over the circumference of the inner surface.

6. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element has an end face (22a) and the end face (22a) on the side facing the inflowing fluid is rounded.

7. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element has two end faces and the end face (22a) on the side facing the inflowing fluid is rounded or angular and the end face on the side facing away from the inflowing fluid is rounded or angular.

8. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element is symmetrically airfoil-profiled.

9. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element is designed as a bulging airfoil.

10. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element is designed with indentations over the axial length.

11. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element is designed with openings / holes in the flow-guiding element, such that an exchange flow from one flow channel to the next occurs.

12. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element tapers in the flow direction of the fluid (or vice versa).

13. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element has a width B, meaning its extent in the tangential direction of the suction port (3) or, respectively, of its inner surface.

14. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element has a width B with a progression of the width B.

15. The ventilation unit according to one of the preceding claims, characterized in that at least one flow-guiding element has a width B which is in the range of 0.4 mm to 2.2 mm.

16. The ventilation unit according to the two preceding claims, characterized in that the ribs (22) extend in the radial direction up to the central axis (9) of the suction port (21) and are in contact with each other there.

17. The ventilation unit according to one of the preceding claims, characterized in that the flow-guiding element (10, 22, 25, 26) extends, in its direction of longitudinal extent, parallel to the central axis (9) of the suction port (3, 21, 23, 24).

18. The ventilation unit according to one of claims 1 to 5, characterized in that the flow-guiding element (10, 22, 25, 26) extends, in its direction of longitudinal extent, at an angle that is tilted relative to the central axis (9) of the suction port (3, 21, 23, 24).

19. The ventilation unit according to the preceding claim, characterized in that the angle is greater than 0° and less than or equal to 45°.

20. The ventilation unit according to one of the preceding claims, characterized in that the ratio between the inlet channel inner diameter (D1) and the inlet channel nominal diameter (DN) is between 0.6 and 1.4, preferably between 0.7 and 1.3, even more preferably between 0.8 and 1.25.

21. The ventilation unit according to one of the preceding claims, characterized in that the ventilation unit (1, 20) is a radial fan unit.

22. The ventilation unit according to at least one of the preceding claims, characterized in that the fan wheel (7) has a plurality of vane elements (29), wherein at least some of the vane elements (29) are equipped in each case with a winglet (31) running at least in portions on at least one axial longitudinal side (30) of the vane element (29).

23. The ventilation unit according to at least one of the preceding claims, characterized in that the winglet (31) has an extent from 1° to 20° of the circumference of the fan wheel (7).

24. The ventilation unit according to at least one of the preceding claims, characterized in that the extent of the winglet (31) increases from the radially inner region of the fan wheel (7) toward the radially outer region of the fan wheel (7).

25. The ventilation unit according to at least one of the preceding claims, characterized in that the fan wheel (7) is equipped with at least one disc (32) on only one axial side and the disc (32) is arranged only on that axial side which is opposite an axial side of the fan wheel (7) equipped with the winglets (31).