Ventilation therapy equipment and fans thereof

Abstract

The present invention discloses a fan, including a volute, an impeller and a motor for driving the impeller to rotate. The volute is provided with a housing for accommodating the impeller. The output end of the motor passes through the volute and is connected to the impeller. The motor includes a housing and a stator and a rotor arranged inside the housing. First axial holes are arranged at both ends of the housing. Both ends of the rotating shaft of the rotor are supported in the first axial holes through bearings. The motor also includes a bearing sleeve arranged in at least one first axial hole, and one end of the bearing is fixedly matched with the bearing sleeve, and the other end of the bearing is fixedly matched with the first axial hole. The present invention can effectively avoid relative sliding between the bearing and the housing; and when the bearing undergoes eccentric motion, it can be buffered by the bearing sleeve, avoiding relative extrusion between the bearing and the housing to damage the bearing or the housing.

Description

Technical Field

[0001] The present invention relates to the field of ventilation therapy equipment, and in particular to ventilation therapy equipment and a fan thereof. Background Art

[0002] With the rapid development of society, the electric motor, as a machine that can convert electrical energy into mechanical energy, mainly includes an electromagnet winding or a distributed stator winding for generating a magnetic field and a rotating armature or rotor. Under the action of the rotating magnetic field of the stator winding, current flows through the effective side of the stator winding and is rotated by the magnetic field. In addition to many machines used in daily life, electric motors are also used in various equipment in the medical field, such as bi-level ventilators and oxygen concentrators.

[0003] In the application of bi-level ventilators and oxygen concentrators, the fan needs to switch between low pressure and high pressure at a certain frequency, and the high and low pressure is achieved by the speed at which the fan blades are driven by the motor in the fan. Therefore, when the fan switches between low pressure and high pressure, the fan blades need to be driven by the motor to accelerate or decelerate rapidly. Existing fans generally include a volute, an impeller, and a motor for driving the impeller to rotate. The impeller is installed in the volute, and the output end of the motor passes through the volute and is connected to the impeller; the motor includes a housing, a rotor, and a bearing; the housing has an installation space for the bearing set and a housing space communicated with the installation space, the rotor is located in the housing space, and the rotor is sleeved in the bearing. However, existing fans have the following defects in actual operation: (1) When the motor accelerates or decelerates rapidly, the friction force on the outer ring of the bearing from the balls inside the bearing increases. When this friction force is greater than the friction force between the outer housing and the outer ring of the bearing, the outer ring of the bearing will rotate with the rotor. At this time, the outer ring of the bearing will rub against the inner wall of the outer housing. The friction between the bearing and the outer housing will cause the temperature of the bearing itself to rise sharply. At the same time, the bearing or the inner wall of the outer housing will be rubbed and a lot of debris will fall off. Under the combined effect of the rapidly rising temperature and the friction debris, the motor rotor will not rotate or the motor will burn out. (2) When the bearing moves eccentrically relative to the outer housing, the bearing and the outer housing will be pressed against each other and damaged.

[0004] Therefore, there is an urgent need for a fan that can stably connect the bearing and the housing and effectively protect the bearing to overcome the above-mentioned defects. Summary of the invention

[0005] The object of the present invention is to provide a fan with a bearing and a housing firmly connected and with the bearing effectively protected.

[0006] Another object of the present invention is to provide a ventilation therapy device, which includes a fan in which the bearing and the housing are firmly connected and the bearing is effectively protected.

[0007] In order to achieve the above-mentioned objectives, the present invention provides a fan, including a volute, an impeller and a motor for driving the impeller to rotate, wherein a receiving chamber for accommodating the impeller is provided in the volute, and an output end of the motor passes through the volute and is connected to the impeller, the motor includes a housing and a stator and a rotor arranged inside the housing, first axial holes are provided at both ends of the housing, and both ends of the rotating shaft of the rotor are supported in the first axial holes through bearings, and the motor also includes a bearing sleeve arranged in at least one of the first axial holes, and one end of the bearing is fixedly matched with the bearing sleeve, and the other end of the bearing is fixedly matched with the first axial hole.

[0008] Preferably, the motor comprises two bearing sleeves, and the two bearing sleeves are arranged facing each other on one side of the two first shaft holes close to the rotor.

[0009] Preferably, there is interference fit between the bearing and the bearing sleeve, and between the bearing sleeve and the first axial hole, and the unit friction force of the bearing sleeve on the bearing is greater than the unit friction force of the first axial hole on the bearing.

[0010] Preferably, the friction coefficient of the bearing is greater than the friction coefficient of the side wall of the first shaft hole.

[0011] Preferably, the interference between the first end of the bearing and the bearing sleeve is greater than the interference between the second end of the bearing and the first axial hole.

[0012] Preferably, the shaft hole is a stepped hole, the bearing sleeve is fixedly arranged at the large diameter of the stepped hole, and the small diameter of the stepped hole is fixedly matched with the bearing.

[0013] Preferably, a protrusion is provided on one of a portion of the first axial hole for assembling the bearing sleeve and an outer side wall of the bearing sleeve, and a groove matching the protrusion is provided on the other portion of the first axial hole for assembling the bearing sleeve and an outer side wall of the bearing sleeve, and the bearing sleeve is assembled in the first axial hole by snap-fitting the protrusion and the groove.

[0014] Preferably, a groove is provided at the step transition of the step hole, a first convex ring is provided at one end of the bearing sleeve, and a second convex ring is provided at the other end of the bearing sleeve, and the first convex ring is clamped in the groove.

[0015] Preferably, the impeller includes a base and a plurality of blades, the blades are fixed to the upper surface of the base, a second axial hole for mounting with a rotating shaft is provided on the base, the head end of the blade is close to the second axial hole, the tail end of the blade is located at the edge of the base, and the portion of the blade located between the head end and the tail end includes a straight section, a first curved section and a second curved section connected end to end, the first curved section and the second curved section are both curved toward the same side, and the curvature of the first curved section is greater than the curvature of the second curved section.

[0016] Preferably, the blade includes a first sheet and a second sheet that are independent of each other, the first sheets are evenly arranged along the upper surface of the base, a first flow channel is formed between two adjacent first sheets, and the second sheet is disposed in the first flow channel.

[0017] Preferably, the second sheet extends from a preset position away from the inlet end of the first flow channel to the outlet end of the first flow channel.

[0018] Preferably, along the extending direction of the first flow channel, the heights of the first sheet and the second sheet gradually decrease.

[0019] Preferably, the head end of the straight section of the first sheet is perpendicular to the upper surface of the base, and the head end of the straight section of the second sheet is inclined to the upper surface of the base.

[0020] Preferably, a balance ring protrudes downward from the lower surface of the base, and the balance ring is arranged along the circumference of the second axial hole.

[0021] Preferably, the volute is provided with a plurality of heat dissipation holes, the heat dissipation holes are located on a side of the volute facing the motor, and the heat dissipation holes are communicated with the accommodating cavity.

[0022] Preferably, a guide groove is provided on the housing, a head end of the guide groove corresponds to a tail end of the heat dissipation hole, and the guide groove is inclined outwards from the head end to the tail end.

[0023] In order to achieve the above object, the present invention also provides a ventilation therapy device, which includes the fan as described above.

[0024] Compared with the prior art, since the fan of the present invention also includes a bearing sleeve arranged in at least one first axial hole, and one end of the bearing is fixedly matched with the bearing sleeve, and the other end of the bearing is fixedly matched with the first axial hole, relative sliding between the bearing and the housing can be effectively avoided; and when the bearing undergoes eccentric movement, it can be buffered by the bearing sleeve, thereby avoiding relative compression between the bearing and the housing and damaging the bearing or the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional view of the fan of the present invention.

[0026] Figure 2 It is a three-dimensional structural schematic diagram of the fan of the present invention.

[0027] Figure 3 It is a cross-sectional view of the motor of the fan of the present invention.

[0028] Figure 4 Schematic diagram of the three-dimensional structure of the bearing sleeve of the fan of the present invention

[0029] Figure 5 It is a cross-sectional view of a bearing sleeve of a fan of the present invention.

[0030] Figure 6 It is a schematic diagram of the three-dimensional structure of the impeller of the fan of the present invention.

[0031] Figure 7 It is a schematic diagram of the three-dimensional structure of the impeller of the fan of the present invention from another angle.

[0032] Figure 8 It is a side view of the impeller of the fan of the present invention.

[0033] Fig. 9 It is a cross-sectional view of an impeller of a fan according to the present invention.

[0034] Fig.10 It is a top view of the impeller of the fan of the present invention.

[0035] Fig.11 It is a schematic diagram of the three-dimensional structure of the first shell of the fan of the present invention.

[0036] Fig.12 It is a schematic diagram of the three-dimensional structure of the second shell of the fan of the present invention.

[0037] Fig.13 It is a partial structural schematic diagram of the motor of the fan of the present invention.

[0038] Fig.14 It is a schematic diagram of the three-dimensional structure of another embodiment of the impeller of the present invention. DETAILED DESCRIPTION

[0039] In order to explain the technical content, structural features and achieved effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0040] Please refer to Figures 1 to 5The fan 100 of the present invention includes a volute 10, an impeller 200, and a motor 300 for driving the impeller 200 to rotate. The volute 10 is provided with a receiving chamber 101 for accommodating the impeller 200, and the output end of the motor 300 passes through the volute 10 and is connected to the impeller 200; the motor 300 includes a housing 310 and a stator and a rotor 320 arranged inside the housing 310, and the housing 310 is provided with first shaft holes 310a at both ends, and the two ends of the rotating shaft of the rotor 320 are supported in the first shaft holes 310a through bearings 330, and the motor 330 also includes a bearing sleeve 340 arranged in at least one first shaft hole 310a, and one end of the bearing 330 is fixedly matched with the bearing sleeve 340, and the other end of the bearing 330 is fixedly matched with the first shaft hole 310a.

[0041] In a specific embodiment, the motor 300 includes two bearing sleeves 340, and the two bearing sleeves 340 are disposed opposite to each other on one side of the two first shaft holes 310a close to the rotor 320, but not limited thereto; more specifically, the bearing 330 and the bearing sleeve 340 and the bearing sleeve 340 and the first shaft hole 310a are both interference fit, and the unit friction force of the bearing sleeve 340 on the bearing 330 is greater than the unit friction force of the shaft hole 10a on the bearing 330. For example, to make the unit friction force of the bearing sleeve 340 on the bearing 330 greater than the unit friction force of the first shaft hole 310a on the bearing 330, the following conditions can be used to achieve: the friction coefficient of the bearing 330 is greater than the friction coefficient of the side wall of the first shaft hole 310a; or the interference between the first end 331 of the bearing 330 and the bearing sleeve 340 is greater than the interference between the second end 332 of the bearing 330 and the first shaft hole 310a; or the above two conditions are met at the same time, but not limited thereto. Preferably, the first shaft hole 310a is a stepped hole, the bearing sleeve 340 is fixedly arranged at the large diameter of the stepped hole, and the small diameter of the stepped hole is fixedly matched with the bearing 330. It is worth noting that the bearing sleeve 340 in the present invention will not rotate relative to the housing 310, but is not limited thereto. More specifically, as follows:

[0042] Please continue to refer to Figures 1 to 5The first shaft hole 310a is provided with a groove 311 at the position where the bearing sleeve 340 is assembled, and a protrusion matching the groove 311 is provided on the outer wall of the bearing sleeve 340. The bearing sleeve 340 is assembled in the shaft hole 10a by the engagement and fixation of the protrusion and the groove 311, so that the bearing sleeve 340 can be effectively prevented from sliding along the shaft hole 10a when the bearing 330 is inserted into the bearing sleeve 340; in other embodiments, a protrusion can also be provided at the position where the shaft hole 10a is used to assemble the bearing sleeve 340, and a groove matching the protrusion 11 can be provided on the outer wall of the bearing sleeve 340, but it is not limited thereto. Specifically, the bearing sleeve 340 has elasticity. For example, the bearing sleeve 340 can be made of materials such as plastic and rubber, but it is not limited thereto.

[0043] Please continue to refer to Figures 1 to 3 , a first convex ring 341, i.e. a protrusion, is provided at one end of the bearing sleeve 340; a second convex ring 342 is provided at the other end of the bearing sleeve 340, and a groove 311 is provided at the step transition of the step hole, and the first convex ring 341 is clamped in the groove 311. Specifically, a first chamfer 3411 is provided on the outer side wall of the first convex ring 341 away from the second convex ring 342, so when the bearing sleeve 340 is inserted into the housing 310, it can be smoother under the guidance of the first chamfer 3411; more specifically, a second chamfer 3421 is provided on the inner side wall of the second convex ring 342 away from the first convex ring 341, so that the bearing 330 can be inserted into the bearing sleeve 340 under the guidance of the second chamfer 3421, but not limited to this. For example, the first chamfer 3411 and the second chamfer 3421 can be 60 degrees, but not limited to this. It is worth noting that, if Figure 1 As shown, the first convex ring 3411 of the motor 100 of the present invention is located in the first shaft hole 310a, and the second convex ring 3421 is located outside the first shaft hole 310a and abuts against the first shaft hole 310a. Therefore, when the bearing 330 is installed in the housing 310, it is only necessary to insert the first convex ring 341 into the first shaft hole 310a, and then the bearing sleeve 340 and the first shaft hole 310a are engaged and fixed, without having to insert the entire bearing sleeve 340 into the first shaft hole 310a, so it is convenient for the installation and removal of the bearing sleeve 340. Specifically, the bearing sleeve 340 and the bearing 330 are in surface contact. Therefore, compared with the line contact formed between the existing O-shaped fastening ring and the bearing 330, the bearing sleeve 340 of the present invention increases the contact area with the bearing 330, thereby making the set between the bearing sleeve 340 and the bearing 330 more stable, but it is not limited thereto.

[0044] Please refer to Figures 6 to 10The impeller 200 of the present invention includes a base 210 and a plurality of blades 220. The blades 220 are fixed to the upper surface of the base 210. The base 210 is provided with a second shaft hole 210a which is mounted to cooperate with the rotating shaft. The head end of the blade 220 is close to the second shaft hole 210a, and the tail end of the blade 220 is located at the edge of the base 210. The portion of the blade 220 between the head end and the tail end includes a straight section 221, a first curved section 222 and a second curved section 223 which are connected end to end. The first curved section 222 and the second curved section 223 are both curved to the same side, and the curvature of the first curved section 222 is greater than the curvature of the second curved section 223. Specifically, the blades 220 are arranged radially with the mounting portion as the center, but are not limited thereto. More specifically, as follows:

[0045] Please continue to refer to Figures 6 to 10 The end 2231 of the second curved section 223 is located at the edge of the base 210, and the end 2231 of the second curved section 223 is inclined to the upper surface of the base 210. This structure is conducive to smoother airflow and can increase the stability of the fan blade operation; preferably, the length of the second curved section 223 is greater than the length of the first curved section 222. Therefore, when the air is pushed to the second curved section 223 by the straight section 221, it is first guided by the first curved section 222 and then thrown out through the second curved section 223 with a smaller curvature and a longer length, which can ensure the dynamic flow of the impeller 200 of the present invention.

[0046] Please continue to refer to Figures 6 to 10The blade 220 includes a first sheet 230 and a second sheet 240 which are independent of each other. The first sheet 230 is evenly arranged along the upper surface of the base 210, and a first flow channel 230a is formed between two adjacent first sheets 230, and the second sheet 240 is arranged in the first flow channel 230a. Specifically, the second sheet 240 extends from a preset position at the inlet end of the first flow channel 230a to the outlet end of the first flow channel 230a; and along the extension direction of the first flow channel 230a, the heights of the first sheet 230 and the second sheet 240 gradually decrease. The unequal height design of the blade 220 reduces the inertia of the wind blade, thereby improving the response speed, and is conducive to the uniform distribution of the fluid, reducing the vortex amount when the airflow passes through the outer edge of the wind blade, so that the pressure stability of the impeller 200 of the present invention during operation is further improved. More specifically, the head end 2301 of the straight section 221 of the first sheet 230 is perpendicular to the upper surface of the base 210, and the head end 2401 of the straight section 221 of the second sheet 240 is inclined to the upper surface of the base 210, so the head end 2301 of the straight section 221 of the first sheet 230 ensures that the impeller 200 has a good flow output, and at the same time, the head end 2401 of the straight section 221 of the second sheet 240 is used to disperse the vortex at the air inlet, which is beneficial to the stability of the impeller 200 during operation. For example, the number of the first sheet 230 is 11, and the number of the second sheet 240 is also 11. Experiments have shown that this number of blades 220 can improve the dynamic stability of the flow field of the impeller 200 of the present invention.

[0047] Please continue to refer to Figures 6 to 10 , the upper surface 211 of the base 210 is a horizontal plane, and the side walls of the base 210 are inclined outward from top to bottom. Specifically, a mounting portion 2111 convex upward is provided in the middle of the upper surface 211 of the base 210, and the second shaft hole 210a extends from the base 210 to the mounting portion 2111; more specifically, the arc transition between the mounting portion 2111 and the base 210 forms a guide surface, which is more conducive to guiding the air at the air inlet, but is not limited to this. Figure 1 As shown, the lower surface 212 of the base 210 is provided with a balancing ring 2121 protruding downward, so any part of the balancing ring 2121 can be cut as needed to ensure the dynamic balance of the impeller 200 of the present invention during operation, but it is not limited thereto. Of course, in other embodiments, such as Fig.14 As shown, the lower surface 212 of the base 210 may further have a plurality of protrusions 2122 protruding downwards, and the protrusions 2122 are arranged along the circumference of the second shaft hole 210a, and the protrusions 2122 are spaced apart from each other.

[0048] Please refer to Figures 1 to 3The volute 10 is provided with a plurality of heat dissipation holes 10a, which are located on the side of the volute 10 facing the motor 300, and the heat dissipation holes 10a are connected with the accommodating chamber 101. Specifically, the housing 310 is provided with a guide groove 310b, and the head end of the guide groove 310b corresponds to the tail end of the heat dissipation hole 10a; more specifically, the guide groove 310b is inclined outward from the head end to the tail end, so when the motor 300 drives the impeller 200 to rotate, the gas in the accommodating chamber 101 will pass through the heat dissipation holes 10a and then, under the guidance of the guide groove 310b, take away the heat generated by the motor 300 itself more comprehensively along the front and rear direction of the motor 300.

[0049] Please refer to Figure 1 , Figure 2 , Figure 3 , Fig.10 , Fig.11 as well as Fig.12 The side of the volute 10 facing the motor 300 is recessed to form a recessed portion 11 for the power supply machine 300 to partially extend into. The output end of the motor 300 passes through the recessed portion 11 and is connected to the impeller 200. The gap 11a between the housing 310 of the motor 300 and the recessed portion 11 connects the guide groove 310b with the outside. Preferably, the heat dissipation hole 10a is located at the portion of the recessed portion 11 facing the impeller 200, which is located between the impeller 200 and the housing 310, and the shape of the recessed portion 11 matches the shape of the housing 310 of the motor 300. The side of the motor 300 provided with the guide groove 310b extends into the recessed portion 11, and the guide groove 310b is connected with the heat dissipation hole 10a, so that the gas in the accommodating chamber 101 is immediately guided by the guide groove 310b and flows outward after passing through the heat dissipation hole 10a. At the same time, due to the restriction of the side wall of the recessed portion 11, the gas flows from front to back along the housing 310 of the motor 300 and takes away the heat of the motor 300, so that the heat dissipation structure of the self-heating fan of the present invention is cleverly set, and the heat inside the motor 300 and the volute 10 can be better conducted away. For example, the outer contour of the cross section of the recessed portion 11 can be set by a technician in this field to be an ellipse, a circle or a regular polygon, etc., but is not limited thereto.

[0050] Please continue to refer to Figure 1 , Figure 2 , Figure 3 , Fig.10 , Fig.11 as well as Fig.12, a first locking hole 11b is also provided on the portion of the recessed portion 11 facing the impeller 200, a second locking hole 310d matching the first locking hole 11b is provided on the side of the housing 310 of the motor 300 facing the recessed portion 11, and a locking member (not shown) passes through the first locking hole 11b and the second locking hole 310d in sequence to lock the motor 300 and the volute 10 together. Therefore, the motor 300 and the recessed portion 11 are detachably locked together by the locking member, so that the connection between the volute 10 and the motor 300 is more secure, and the disassembly and assembly of the volute 10 and the motor 300 is convenient, but the invention is not limited thereto.

[0051] Please refer to Figures 10 to 12 The volute 10 includes a first shell 110 and a second shell 120. The first shell 110 and the second shell 120 together form a receiving chamber 101, and the recessed portion 11 is provided on the second shell 120. Specifically, a first fixing portion 111 is provided on the first shell 110, and a second fixing portion 121 matching the first fixing portion 111 is provided on the second shell 120, and the first shell 110 and the second shell 120 are connected by the first fixing portion 111 and the second fixing portion 121; for example, the first fixing portion 111 can be a male buckle, and the second fixing portion 121 can be a female buckle, so the first shell 110 and the second shell 120 can be connected by the male buckle and the female buckle being mutually buckled; in addition, the first fixing portion 111 and the second fixing portion 121 can also be respectively set as screw holes, and a screw (not shown in the figure) is sequentially passed through the first fixing portion 111 and the second fixing portion 121 to realize the detachable connection of the first shell 110 and the second shell 120. Since the volute 10 is composed of the first shell 110 and the second shell 120 connected together, it is convenient to disassemble, transport and store the volute 10, and it is also convenient to disassemble the volute 10 and clean the inside thereof.

[0052] like Figure 1 As shown, the volute 10 is provided with an air inlet 130 and an air outlet 140. When the motor 300 drives the impeller 200 to rotate, the air pressure in the accommodating chamber 101 increases, and a part of the airflow is discharged from the air outlet 140. Since a plurality of heat dissipation holes 10a are provided on the second housing 120, another part of the airflow is discharged from the heat dissipation holes 10a, and moves along the gap 11a to achieve heat dissipation of the motor 300. Tests have shown that it only takes 80 milliseconds for the fan 100 of the present invention to accelerate from 10,000 rpm to 30,000 rpm, and it only takes 180 milliseconds to push the fan blades from 10,000 rpm to 30,000 rpm. The dual-speed switching time of the fan 100 of the present invention is very short. With the low-inertia fan blade and stable flow field design, the entire fan 100 has the beneficial effects of improved response speed, reduced noise, good dynamic pressure stability, good heat dissipation and small size.

[0053] In other embodiments, the motor 300 is provided with only one bearing sleeve 340 , and the bearing sleeve 340 can be provided in any one of the two first shaft holes 310 a .

[0054] It is worth noting that the present invention also discloses a ventilation therapy device, which includes the above-mentioned fan, wherein the ventilation therapy device can be a ventilator or an oxygen generator, etc., so it is not described one by one here.

[0055] Compared with the prior art, since the fan 100 of the present invention also includes a bearing sleeve 340 arranged in at least one first shaft hole 310a, and one end of the bearing 330 is fixedly matched with the bearing sleeve 340, and the other end of the bearing 330 is fixedly matched with the first shaft hole 310a, relative sliding between the bearing 330 and the housing 310 can be effectively avoided; and when the bearing 330 undergoes eccentric motion, it can be buffered by the bearing sleeve 340, thereby avoiding relative extrusion between the bearing 330 and the housing 310 and damaging the bearing 330 or the housing 310.

[0056] The above disclosure is only a preferred embodiment of the present invention, which is intended to facilitate the understanding and implementation of the present invention by those skilled in the art. It certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. A fan, comprising a volute, an impeller and a motor for driving the impeller to rotate, wherein a receiving chamber for accommodating the impeller is provided in the volute, an output end of the motor passes through the volute and is connected to the impeller, the motor comprises a housing and a stator and a rotor arranged inside the housing, first shaft holes are provided at both ends of the housing, and both ends of the rotating shaft of the rotor are supported in the first shaft holes through bearings, characterized in that: The motor also includes a bearing sleeve arranged in at least one of the first shaft holes, and one end of the bearing is fixedly matched with the bearing sleeve, and the other end of the bearing is fixedly matched with the first shaft hole. The motor includes two bearing sleeves, and the two bearing sleeves are arranged opposite to each other on one side of the two first shaft holes close to the rotor. The bearing and the bearing sleeve and the bearing sleeve and the first shaft hole are both interference fit, and the unit friction force of the bearing sleeve on the bearing is greater than the unit friction force of the bearing on the first shaft hole. The shaft hole is a step hole, and the bearing sleeve is fixedly arranged at the large diameter of the step hole, and the small diameter of the step hole is fixedly matched with the bearing. A protrusion is provided on one of the portion of the first shaft hole for assembling the bearing sleeve and the outer wall of the bearing sleeve, and a groove matching the protrusion is provided on the portion of the first shaft hole for assembling the bearing sleeve and the outer wall of the bearing sleeve, and the bearing sleeve is assembled in the first shaft hole by the engagement and fixing of the protrusion and the groove.

2. The fan according to claim 1, characterized in that: The friction coefficient of the bearing is greater than the friction coefficient of the side wall of the first shaft hole.

3. The fan according to claim 1, characterized in that: The interference between the first end of the bearing and the bearing sleeve is greater than the interference between the second end of the bearing and the first shaft hole.

4. The fan according to claim 1, characterized in that: A groove is arranged at the step transition of the step hole, a first convex ring is arranged at one end of the bearing sleeve, and a second convex ring is arranged at the other end of the bearing sleeve, and the first convex ring is clamped in the groove.

5. The fan according to claim 1, characterized in that: The impeller includes a base and a plurality of blades, wherein the blades are fixed to the upper surface of the base, and a second axial hole is provided on the base for mounting with the rotating shaft, the head end of the blade is close to the second axial hole, and the tail end of the blade is located at the edge of the base, and the portion of the blade located between the head end and the tail end sequentially includes a straight section, a first curved section and a second curved section that are butt-jointed end to end, the first curved section and the second curved section are both curved toward the same side, and the curvature of the first curved section is greater than the curvature of the second curved section.

6. The fan according to claim 5, characterized in that: The blade includes a first sheet and a second sheet that are independent of each other. The first sheets are evenly arranged along the upper surface of the base, and a first flow channel is formed between two adjacent first sheets. The second sheet is arranged in the first flow channel.

7. The fan according to claim 6, characterized in that: The second sheet extends from a preset position away from the inlet end of the first flow channel to the outlet end of the first flow channel.

8. The fan according to claim 6, characterized in that: Along the extending direction of the first flow channel, the heights of the first sheet body and the second sheet body gradually decrease.

9. The fan according to claim 6, characterized in that: The head end of the straight section of the first sheet is perpendicular to the upper surface of the base, and the head end of the straight section of the second sheet is inclined to the upper surface of the base.

10. The fan according to claim 1, characterized in that: A balance ring protrudes downward from the lower surface of the base, and the balance ring is arranged along the circumference of the second shaft hole.

11. The fan according to claim 1, characterized in that: The volute is provided with a plurality of heat dissipation holes, the heat dissipation holes are located on a side of the volute facing the motor, and the heat dissipation holes are communicated with the accommodating cavity.

12. The fan according to claim 11, characterized in that: A guide groove is provided on the shell, the head end of the guide groove corresponds to the tail end of the heat dissipation hole, and the guide groove is inclined outwards from the head end to the tail end.

13. A ventilation therapy device, characterized in that: The ventilation therapy device comprises a blower as claimed in any one of claims 1-12.

Images