Turbofan shell, centrifugal turbofan and breathing machine

Abstract

The utility model discloses a turbofan shell, centrifugal turbofan and breathing machine, wherein the turbofan shell comprises a volute upper cover, a volute lower cover fixedly installed below the volute upper cover, an air flow channel forming circumferential uniform section and an air outlet communicated with the air flow channel, the air outlet is tangent to the air flow channel, and the centrifugal turbofan is arranged in the volute lower cover. An air inlet is formed in the top of the volute upper cover, a filling block which is installed on the volute upper cover and is of a spiral structure is arranged in the airflow channel, the starting end of the filling block is located at a circumferential inlet of the airflow channel, and the tail end of the filling block right faces the air outlet. And the thickness of the filling block is linearly reduced to zero from the starting end along with the increase of the circumferential angle of the airflow channel. According to the utility model, the filling block with the spiral structure is arranged, and the thickness of the filling block is gradually reduced, so that the runner area of the airflow channel is gradually increased along with the increase of the circumferential angle in the circumferential direction, the flow change of airflow is better met, the pneumatic efficiency is improved, and the noise is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of turbine fans, in particular to a turbine fan housing, a centrifugal turbine fan and a ventilator. Background Art

[0002] A ventilator is an extracorporeal respiratory gas source providing device for respiratory therapy or assisted ventilation. The turbine fan is one of the core components of the ventilator. The flow and pressure required by the ventilator come from the turbine fan. The pressure, flow and noise performance of the turbine fan are directly related to the performance of the ventilator. Medical emergency ventilators mainly focus on the maintenance and recovery functions of respiratory physiological special diagnosis, and have a relatively high tolerance for noise. Home ventilators are often used in non-emergency situations, such as the improvement of sleep apnea (commonly known as snoring). Users have a more stringent tolerance for noise and hope that the ventilator will not produce noise interference to ensure a quiet sleeping environment. To improve sleep breathing, the application of home ventilators is becoming more and more popular. The noise value of the whole ventilator and the air volume and pressure of the air supply are important performance indicators of the ventilator, and the centrifugal fan is the core component of the ventilator. Its single-machine noise, flow and pressure performance directly affect the performance indicators of the whole ventilator. For fan manufacturers, improving the performance of the single centrifugal fan has always been a goal and unremitting efforts to improve product competitiveness.

[0003] The centrifugal turbine fan is the main source of ventilator noise. The volute is an important fixed component of the centrifugal turbine fan. Its function is to collect the gas behind the impeller and discharge it in a centralized manner. The design of the volute surface will also directly affect the noise, flow rate and pressure performance indicators of the centrifugal fan. At present, the volute of the centrifugal fan used in the ventilator mostly adopts the form of equal cross-section along the circumference. This kind of volute has a simple structure and is easy to manufacture. It is currently widely used. Figure 1 As shown, since the gas flow rate increases linearly along the circumferential direction when it comes out of the impeller, this volute cannot adapt to this requirement well, resulting in low aerodynamic efficiency and low-frequency noise. Utility Model Content

[0004] The purpose of the utility model is to propose a turbine fan housing, a centrifugal turbine fan and a respirator in view of the deficiencies of the prior art, and to reduce noise by optimizing the structure of the existing volute.

[0005] The technical solution to achieve the purpose of this utility model is:

[0006] A turbine fan casing comprises a volute upper cover and a volute lower cover fixedly mounted below the volute upper cover, forming an airflow channel with a circumferentially uniform cross-section and an air outlet connected to the airflow channel, wherein the air outlet is arranged tangent to the airflow channel, an air inlet is arranged on the top of the volute upper cover, a filling block with a spiral structure mounted on the volute upper cover is arranged in the airflow channel, a starting end of the filling block is located at the circumferential entrance of the airflow channel, and a terminal end is opposite to the air outlet, and a thickness of the filling block decreases linearly from the starting end to zero as the circumferential angle of the airflow channel increases.

[0007] Furthermore, an intermediate partition is provided in the air flow channel, and the intermediate partition includes a main body section with a ring-like structure and a straight section extending circumferentially along the main body section, the outer peripheral surface of the main body section is in sealing contact with the inner ring of the filling block, and the straight section is smoothly connected to the inner wall of the air outlet on the side close to the axis of the volute upper cover.

[0008] Furthermore, the main body segment includes a first arc segment and a second arc segment which are smoothly connected to each other, the first arc segment is a circular arc, the second arc segment is a variable diameter spiral arc, and the radius of the spiral arc decreases linearly with the increase of the circumferential angle.

[0009] Furthermore, the helix angle of the helical arc is 270°.

[0010] Furthermore, the helix angle of the filling block is 300°.

[0011] Furthermore, an expansion angle is provided between a section of the outer ring of the filling block close to the air outlet and the outer ring of the air flow channel, and the expansion angle is 2±0.5°.

[0012] A centrifugal turbine fan comprises a turbine fan housing as described above, wherein a motor is fixedly arranged in the lower cover of the volute, a centrifugal impeller assembly facing an air inlet is coaxially fixedly mounted on the output shaft of the motor, and the centrifugal impeller assembly is located in an air flow channel.

[0013] A ventilator comprises the centrifugal turbine blower as described above.

[0014] By adopting the above technical solution, the utility model has the following beneficial effects:

[0015] (1) The utility model provides a filling block with a spiral structure and the thickness of the filling block gradually decreases, so that the flow area of ​​the airflow channel gradually increases in the circumferential direction as the circumferential angle increases, which is more in line with the flow change of the airflow, improves the aerodynamic efficiency, and reduces noise.

[0016] (2) The utility model provides a middle partition with a special structure, thereby reducing the airflow circulation phenomenon in the inner circle of the middle partition and further reducing low-frequency noise. At the same time, most of the volute noise is generated at the volute tongue. The existence of the middle partition blocks the noise at the volute tongue from propagating to the fan inlet, thereby greatly reducing the noise at the fan inlet.

[0017] (3) The utility model controls the specific sizes of the filling block and the partition plate, and the two cooperate to form a flow channel area with a special structure, thereby achieving the optimal state of air flow rate and noise.

[0018] (4) The utility model sets the expansion angle so that the air outlet is slightly expanded, which greatly reduces the pressure loss of the volute and improves the pressure diffusion performance, making the air flow pressure at the volute outlet higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the content of the utility model easier to understand, the utility model is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein:

[0020] Figure 1 This is the CFD simulation streamline diagram of the existing circular uniform cross-section volute;

[0021] Figure 2 It is a three-dimensional diagram of the utility model;

[0022] Figure 3 It is a cross-sectional view of the utility model;

[0023] Figure 4 It is a structural schematic diagram of the volute upper cover of the utility model;

[0024] Figure 5 This is a schematic diagram of the change of the filling block profile of the utility model;

[0025] Figure 6 It is a schematic diagram of the profile change of the middle partition of the utility model.

[0026] The reference numerals in the accompanying drawings are:

[0027] Volute upper cover 1, volute lower cover 2, air inlet 3, air outlet 4, centrifugal impeller assembly 5, filling block 6, middle partition 7, main body section 7-1, straight section 7-2. DETAILED DESCRIPTION

[0028] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0029] (Example 1)

[0030] In order to improve sleep breathing, the application of home ventilators is becoming more and more popular. This embodiment provides a ventilator, including a centrifugal turbine fan, such as Figures 2 to 6 As shown, the centrifugal turbine fan comprises a turbine fan housing composed of a volute upper cover 1 and a volute lower cover 2, wherein the top of the volute upper cover 1 is provided with an air inlet 3, and the volute lower cover 2 is fixedly installed below the volute upper cover 1, forming an air flow channel with a circumferential equal cross-section and an air outlet 4 connected to the air flow channel and arranged straightly in the horizontal direction, and the air outlet 4 is arranged tangentially to the air flow channel. A motor is fixedly installed in the volute lower cover 2, and a centrifugal impeller assembly 5 facing the air inlet 3 and located in the air flow channel is coaxially fixedly installed on the output shaft of the motor. A filling block 6 with a spiral structure installed on the volute upper cover 1 is provided in the air flow channel, and the helix angle of the filling block is 300°. The starting end of the filling block 6 is located at the circumferential entrance of the air flow channel, that is, the volute tongue, and the end is facing the air outlet 4, and the thickness of the filling block 6 decreases linearly to zero from the starting end as the circumferential angle of the air flow channel increases. By providing a filling block with a spiral structure and gradually reducing the thickness of the filling block, the flow area of ​​the airflow channel gradually increases in the circumferential direction as the circumferential angle increases, which is more in line with the flow change of the airflow, improves the aerodynamic efficiency and reduces noise.

[0031] like Figure 1 As shown in FIG. 1 , CFD simulation shows that there is a serious circulation in the area near the inner circle of the airflow channel, which will inevitably generate low-frequency noise. Therefore, in this embodiment, a middle partition 7 is provided in the airflow channel. The middle partition 7 includes a main section 7-1 of a ring-like structure and a straight section 7-2 extending circumferentially along the main section 7-1, wherein the outer peripheral surface of the main section 7-1 is in sealing contact with the inner circle of the filling block 6, and the straight section 7-2 is smoothly connected to the inner wall of the air outlet 4 near the axis of the upper cover of the volute. By setting the middle partition 7 of a special structure, the airflow circulation phenomenon in the inner circle of the middle partition 7 is reduced, and the low-frequency noise is further reduced. At the same time, most of the volute noise is generated at the volute tongue. The existence of the middle partition 7 blocks the noise at the volute tongue from propagating to the fan inlet, so that the noise at the fan inlet is greatly reduced. The main section 7-1 includes a first arc section and a second arc section that are smoothly connected, wherein the first arc section is a circular arc, and the second arc section is a variable diameter spiral arc, the helix angle of the spiral arc is 270°, and the radius of the spiral arc decreases linearly with the increase of the circumferential angle. By controlling the specific sizes of the filling block and the partition, the two cooperate to form a flow channel area of ​​a special structure, thereby achieving the optimal state of air flow and noise. At the same time, the filling block 6 and the middle partition 7 are integrally formed with the volute upper cover 1, which is convenient for production.

[0032] In order to further increase the airflow pressure, an expansion angle is provided between a section of the outer circle of the filling block 6 of the present embodiment close to the air outlet 4 and the outer circle of the airflow channel, wherein the expansion angle is 2±0.5°, so that the air outlet is slightly expanded, which greatly reduces the pressure loss of the volute, and at the same time improves the pressure expansion performance, so that the airflow pressure at the volute outlet is higher.

[0033] In this embodiment, the thickness of the filling block 6 is reduced and the radial size of the middle partition 7 is reduced, so that the flow channel area of ​​the volute increases in the circumferential direction as the circumferential angle increases. At the same time, the outlet straight section is slightly expanded, so that the pressure loss of the volute is greatly reduced, and the pressure diffusion performance is improved, so that the air flow pressure at the volute outlet is higher; the presence of the middle partition 7 greatly weakens the circulation and reduces the low-frequency noise; most of the volute noise is generated at the volute tongue, and the presence of the middle partition 7 blocks the noise at the volute tongue from propagating to the fan inlet, so that the noise at the fan inlet is greatly reduced.

[0034] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A turbine fan housing, characterized in that: It includes a volute upper cover and a volute lower cover fixedly installed below the volute upper cover, forming an airflow channel with a circumferentially equal cross-section and an air outlet connected to the airflow channel, the air outlet is arranged tangent to the airflow channel, the top of the volute upper cover is provided with an air inlet, and the airflow channel is provided with a filling block installed on the volute upper cover and having a spiral structure, the starting end of the filling block is located at the circumferential entrance of the airflow channel, and the end is opposite to the air outlet, and the thickness of the filling block decreases linearly from the starting end to zero as the circumferential angle of the airflow channel increases.

2. A turbo blower housing according to claim 1, characterized in that: An intermediate partition is provided in the air flow channel, and the intermediate partition includes a main body section with a ring-like structure and a straight section extending circumferentially along the main body section. The outer peripheral surface of the main body section is in sealing contact with the inner ring of the filling block, and the straight section is smoothly connected to the inner wall of the air outlet on the side close to the axis of the volute upper cover.

3. A turbo blower housing according to claim 2, characterized in that: The main body segment includes a first arc segment and a second arc segment which are smoothly connected to each other. The first arc segment is a circular arc, and the second arc segment is a variable-diameter spiral arc. The radius of the spiral arc decreases linearly with the increase of the circumferential angle.

4. A turbo blower housing according to claim 3, characterized in that: The helix angle of the helical arc is 270°.

5. A turbo blower housing according to claim 1, characterized in that: The helix angle of the filling block is 300°.

6. A turbo blower housing according to claim 1, characterized in that: An expansion angle is provided between a section of the outer ring of the filling block close to the air outlet and the outer ring of the air flow channel, and the expansion angle is 2±0.5°.

7. A centrifugal turbine fan, characterized in that: It comprises a turbine blower casing as claimed in any one of claims 1 to 6, wherein a motor is fixedly provided in the lower cover of the volute, a centrifugal impeller assembly facing the air inlet is coaxially fixedly mounted on the output shaft of the motor, and the centrifugal impeller assembly is located in the air flow channel.

8. A ventilator, characterized in that: Comprising the centrifugal turbine blower as claimed in claim 7.

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