Compact single-stage high-speed centrifugal blower

Abstract

The invention discloses a compact single-stage high-speed centrifugal blower. The centrifugal blower comprises a driving part, a transmission part and a pneumatic part, the driving part comprises a permanent magnet synchronous motor, and the transmission part comprises a transmission box body, a large gear arranged on a motor shaft of the permanent magnet synchronous motor, a driven shaft arranged in the transmission box body through two high-speed sliding bearings and a small gear meshed with the large gear; wherein the small gear and the large gear are meshed to form a transmission pair, a sliding bearing is fixedly installed on the side wall, facing the driving part, of the transmission box body, the sliding bearing and the motor shaft form a rotating pair, and the driven shaft and the high-speed sliding bearing form a rotating pair. The general machine is efficient and energy-saving, two radial sliding bearings and two thrust bearings on a low-speed shaft in the prior art are omitted, the power consumption of the bearings is reduced, the structure is compact, the cost is low, and the applicability is high.

Description

Technical Field

[0001] This invention relates to the field of centrifugal blowers, and in particular to a compact single-stage high-speed centrifugal blower. Background Technology

[0002] A single-stage high-speed centrifugal blower is a type of fluid machinery that uses a high-speed rotating impeller to compress gas in a single stage. Its core feature is that it converts kinetic energy into pressure energy through centrifugal force. The gas enters the impeller axially, gains kinetic energy through high-speed rotation, decelerates and increases pressure in the diffuser, and finally collects and outputs through the volute. A single-stage compression can achieve a pressure range of 49~200kPa. Due to its high efficiency and energy saving, the single-stage high-speed centrifugal blower is widely used in industries such as industrial waste gas treatment and sewage treatment.

[0003] Conventional single-stage high-speed centrifugal blowers suffer from problems such as lower aerodynamic efficiency and poorer energy-saving effect with smaller rated flow, larger space occupation and high price, which limit their promotion and application in engineering projects with strict space requirements, such as small sewage treatment plants. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a compact single-stage high-speed centrifugal blower that is low in cost, has high transmission efficiency, and is energy-efficient.

[0005] A compact single-stage high-speed centrifugal blower includes a drive unit, a transmission unit, and a pneumatic unit. The drive unit includes a permanent magnet synchronous motor. The transmission unit includes a transmission housing, a large gear mounted on the motor shaft of the permanent magnet synchronous motor, a driven shaft mounted in the transmission housing via two high-speed sliding bearings, and a small gear meshing with the large gear. The small gear and the large gear mesh to form a transmission pair. A sliding bearing is fixedly installed on the side wall of the transmission housing facing the drive unit, forming a rotating pair with the motor shaft. The driven shaft also forms a rotating pair with the high-speed sliding bearing.

[0006] As a further improvement to the above scheme, two high-speed sliding bearings are respectively installed on both sides of the transmission housing.

[0007] As a further improvement to the above solution, the permanent magnet synchronous motor has a cooling channel in the mounting base for supporting the iron core and stator windings. The cooling channel has a circulating part and a branch part, which are connected and the branch part is located in the middle of two connected stator windings.

[0008] As a further improvement to the above solution, the two end caps of the permanent magnet synchronous motor are respectively provided with a liquid inlet and a liquid outlet. The liquid outlet is located close to the transmission part, and both the liquid inlet and the liquid outlet are connected to the cooling channel.

[0009] As a further improvement to the above solution, the mounting base is provided with two heat-conducting plates, the permanent magnet synchronous motor rotor is located between the two heat-conducting plates, and there is an air gap between the rotor and the heat-conducting plates. In this invention, the heat-conducting plates are close to the cooling surface formed by the cooling channel, which can cool the stator and rotor by means of thermal convection. At the same time, the two heat-conducting plates work together to limit the permanent magnet, preventing displacement and detachment.

[0010] As a further improvement to the above solution, the heat-conducting plate is circular and can be detachably mounted on the mounting base by screws. A through cavity for the motor shaft to pass through is opened at the center of the heat-conducting plate.

[0011] As a further improvement to the above solution, the permanent magnet synchronous motor is fixedly installed on the corresponding side of the transmission housing, and one end of the motor shaft extends into the transmission housing.

[0012] As a further improvement to the above solution, the large gear is fixed to the end of the motor shaft with screws, and the small gear is fixedly sleeved on the driven shaft.

[0013] As a further improvement to the above scheme, two thrust discs are fixedly sleeved on the driven shaft, and the meshing surfaces of the large gear and the small gear are located between the two thrust discs.

[0014] As a further improvement to the above solution, the pneumatic part includes a volute, an impeller and a diffuser. The volute is fixedly installed on the opposite side of the transmission housing, and one end of the driven shaft extends into the volute. The volute has an inner volute and an outer volute.

[0015] As a further improvement to the above solution, the impeller is located in the inner volute and is fixedly installed at the end of the driven shaft. A front cover is provided on the side of the inner volute facing away from the transmission housing, and the front cover and the inner volute form an air intake channel. An air outlet channel is provided at a position of the volute away from the air intake channel. Several air intake guide vanes are provided between the front cover and the inner volute, and the several air intake guide vanes are evenly distributed along the circumference in the air intake channel.

[0016] As a further improvement to the above scheme, the diffuser is a bladeless diffuser, wherein the diffuser seat and the inner volute form the bladeless diffuser.

[0017] As a further improvement to the above scheme, the diffuser may be a fixed guide vane diffuser; or the diffuser may be an adjustable guide vane diffuser.

[0018] Compared with the prior art, the beneficial effects of the present invention are: This invention features a highly efficient and energy-saving main unit. It replaces the asynchronous motor with a permanent magnet synchronous motor, thereby improving motor efficiency. The high-speed shaft is directly driven by gears on the motor, eliminating the need for two radial sliding bearings and two thrust bearings on the low-speed shaft in the original technology. This reduces bearing power consumption and improves transmission efficiency.

[0019] This invention uses a permanent magnet synchronous motor as the driving component to provide rotational force, avoiding the slip loss and excitation energy consumption of conventional electric motor driving components. It achieves higher electrical conversion efficiency and significantly reduced energy consumption during operation. At the same time, the permanent magnet synchronous motor is structurally improved to meet the heat dissipation requirements under high-speed conditions and overcomes the defects of insufficient stability of permanent magnets under high-speed conditions, which can easily lead to displacement or even detachment under strong centrifugal force, resulting in rotor imbalance. It can be better adapted to the working conditions of high-speed centrifugal blowers.

[0020] This invention reduces the transmission center distance, overall machine size, and manufacturing cost. It eliminates the original low-speed shaft and bearings, further reducing the overall price. Both volume and cost are reduced by 30% to 50%, making it suitable for small sewage treatment plants and engineering projects with strict space requirements. Attached Figure Description

[0021] Figure 1 The image shown is a front view of a compact single-stage high-speed centrifugal blower provided by the present invention.

[0022] Figure 2 As shown Figure 1 Top view.

[0023] Figure 3 As shown Figure 1 A cross-sectional view of a permanent magnet synchronous motor.

[0024] Figure 4 As shown Figure 3 BB cross-sectional view.

[0025] Figure 5 The figure shown is a cross-sectional view of a compact single-stage high-speed centrifugal blower provided in Embodiment 1 of the present invention.

[0026] Figure 6 The figure shown is a cross-sectional view of a compact single-stage high-speed centrifugal blower provided in Embodiment 2 of the present invention.

[0027] Figure 7 The figure shown is a cross-sectional view of a compact single-stage high-speed centrifugal blower provided in Embodiment 3 of the present invention.

[0028] Figure 8 The figure shown is an enlarged cross-sectional view of the inlet guide vane adjustment structure of a compact single-stage high-speed centrifugal blower provided in Embodiment 4 of the present invention.

[0029] Explanation of main component symbols 1. Permanent magnet synchronous motor; 2. Motor shaft; 3. Transmission housing; 4. Large gear; 5. Driven shaft; 6. Small gear; 7. Outer volute; 8. Inner volute; 9. Impeller; 10. Bladeless diffuser; 11. Fixed guide vane diffuser; 12. Adjustable guide vane diffuser; 13. Circulating section; 14. Branch section; 15. Heat-conducting fin; 16. Front cover; 17. Inlet guide vane; 18. Sliding bearing; 19. High-speed sliding bearing; 20. Thrust disc; 21. Diffuser seat; 22. Electric actuator; 23. Rotating ring; 24. Guide bearing; 25. Eccentric sleeve; 26. Ball; 27. Shift fork; 28. Flat key.

[0030] The above description of the main component symbols, together with the accompanying drawings and specific embodiments, provides a more detailed explanation of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. It should be understood that the following description is merely illustrative and not intended to limit the invention.

[0032] The specific embodiments of the present invention will be described in detail below.

[0033] Example 1 Please see Figures 1-5 This embodiment provides a compact single-stage high-speed centrifugal blower, which includes a drive unit, a transmission unit, and a pneumatic unit. The drive unit includes a permanent magnet synchronous motor 1. In this embodiment, the permanent magnet synchronous motor 1 is used as the drive component to provide rotational force. The iron core and permanent magnets form the rotor. The rotating magnetic field generated when the stator is energized and the constant magnetic field generated by the permanent magnets interact to cause the motor shaft 2 to rotate. Since the rotor is not energized, no excitation current is required, avoiding the slip loss and excitation energy consumption in the conventional mode of using an electric motor as the drive component. During operation, the electrical conversion efficiency is higher and the energy consumption is significantly reduced.

[0034] In the permanent magnet synchronous motor 1, a cooling channel is provided within the mounting base that supports the iron core and stator windings. The two end caps of the permanent magnet synchronous motor 1 have liquid inlets and outlets, respectively. The outlet is located near the transmission section, and both the inlet and outlet are connected to the cooling channel. The cooling channel includes a circulating section 13 and a branch section 14, which are connected. The branch section 14 is located between two connected stator windings. In this embodiment, the cooling medium flows along the cooling channel formed by the circulating section 13 and the branch section 14, thereby carrying away heat to achieve a cooling effect. Furthermore, the cooling channel is located within the mounting base, with the circulating section 13 arranged along the curved surface of the mounting base and the branch section 14 close to the stator windings. The cooling surface acts on the heat-generating area, resulting in better heat dissipation. Only the mounting base needs modification, without requiring modification of the motor housing, thus saving costs.

[0035] Two heat-conducting plates 15 are provided on the mounting base. The rotor of the permanent magnet synchronous motor 1 is located between the two heat-conducting plates 15, and there is an air gap between the rotor and the heat-conducting plates 15. The heat-conducting plates 15 are circular and are detachably mounted on the mounting base by screws. A through cavity for the motor shaft 2 to pass through is opened at the center of the heat-conducting plate 15. In this embodiment, the heat-conducting plates 15 are designed so that, on the one hand, they are close to the cooling surface formed by the cooling channel, and the stator and rotor can be cooled down by heat convection; on the other hand, the two heat-conducting plates 15 work together to limit the permanent magnet, preventing displacement and detachment.

[0036] In this embodiment, the permanent magnet synchronous motor 1 is structurally improved to meet the heat dissipation requirements under high-speed conditions and overcome the defects of insufficient stability of permanent magnets under high-speed conditions, which are prone to displacement or even detachment under strong centrifugal force, leading to rotor imbalance. It can be better adapted to the working conditions of high-speed centrifugal blowers.

[0037] The transmission unit includes a transmission housing 3, a large gear 4 mounted on the motor shaft of the permanent magnet synchronous motor 1, a driven shaft 5 mounted inside the transmission housing 3 via two high-speed sliding bearings 19, and a small gear 6 meshing with the large gear 4. The permanent magnet synchronous motor 1 is fixedly installed on the corresponding side of the transmission housing 3, and one end of the motor shaft 2 extends into the transmission housing 3. The large gear 4 is fixed to the end of the motor shaft 2 with screws, and the small gear 6 is located on the driven shaft 5. In this embodiment, the large gear 4 has more teeth, and the small gear 6 has fewer teeth. When the large gear 4 drives the small gear 6 to rotate, the small gear 6 rotates faster than the large gear 4. Therefore, the driven shaft 5 drives the impeller 9 to rotate at a higher speed than the motor shaft 2. The small gear 6 and the large gear 4 mesh to form a transmission pair. A sliding bearing 18 is fixedly installed on the side wall of the transmission housing 3 facing the drive unit, and the sliding bearing 18 forms a rotating pair with the motor shaft 2. Driven shaft 5 and high-speed sliding bearing 19 form a rotating pair, with the two high-speed sliding bearings 19 respectively located on both sides of transmission housing 3.

[0038] Two thrust discs 20 are fixedly sleeved on the driven shaft 5, and the meshing surfaces of the large gear 4 and the small gear 6 are located between the two thrust discs 20. The thrust discs 20 and the small gear 6 are fixed together. In order to ensure that the meshing transmission part can only rotate and does not produce displacement in other directions, this embodiment sets two thrust discs 20 to prevent the driven shaft 5 from moving axially.

[0039] The pneumatic component includes a volute, an impeller 9, and a diffuser. The volute is fixedly mounted on the opposite side of the transmission housing 3, and one end of the driven shaft 5 extends into the volute. The volute includes an inner volute 8 and an outer volute 7, which work together to collect and guide the gas and further reduce the flow velocity, converting some kinetic energy into static pressure and improving pneumatic efficiency. In this embodiment, the use of a permanent magnet synchronous motor 1 with a speed of up to 6000 r / min reduces the gear speed ratio, thereby reducing the gear transmission center distance, resulting in a compact structure, reduced manufacturing costs, and improved product cost-effectiveness.

[0040] The impeller 9 is located in the inner volute 8 and is fixedly installed at the end of the driven shaft 5. A front cover 16 is provided on the side of the inner volute 8 facing away from the transmission housing 3, and the front cover 16 and the inner volute 8 form an inlet air passage. An outlet air passage is provided at a position on the volute away from the inlet air passage. Several inlet guide vanes 17 are arranged between the front cover 16 and the inner volute 8, and these inlet guide vanes 17 are evenly distributed circumferentially within the inlet air passage. In this embodiment, the inlet guide vanes 17 guide air axially into the inlet air passage and reduce inlet flow vortex disturbance. The inlet guide vanes 17 in this embodiment are adjustable, thereby achieving airflow regulation. The aforementioned flow regulation design is a mature existing technology and will not be elaborated here. The diffuser in this embodiment is a bladeless diffuser 10. The diffuser seat 21 and the inner volute 8 form an annular bladeless diffuser 10. After the airflow leaves the impeller 9, it enters the bladeless diffuser 10, where the airflow decelerates, converting kinetic energy into pressure energy, increasing static pressure and efficiency. This embodiment is suitable for operating conditions where the flow rate adjustment range is not large.

[0041] The centrifugal blower of this embodiment operates as follows: the permanent magnet synchronous motor 1 drives the motor shaft to rotate. Under the meshing transmission of the large gear 4 and the small gear 6, the driven shaft 5 drives the impeller 9 to rotate at high speed. Air enters along the air intake channel and enters the impeller 9 axially. The high-speed rotation of the impeller 9 does work on the airflow, making the airflow obtain a high tangential velocity. The air in the air intake is converted into kinetic energy by the centrifugal force of the impeller 9. The diffuser decelerates the airflow and converts the kinetic energy into pressure energy, increasing static pressure and efficiency. The volute collects and guides the gas and further reduces the flow velocity, converting some of the kinetic energy into static pressure and improving aerodynamic efficiency.

[0042] Example 2 Please refer to the following: Figure 6The difference between this embodiment and Embodiment 1 is that the diffuser in this embodiment is a fixed guide vane diffuser 11. That is, based on the bladeless diffuser 10 of Embodiment 1, 11 guide vanes are added. The 11 guide vanes are evenly distributed in a ring and fixed on the diffuser seat 21. The centrifugal blower in this embodiment works on the same principle as in Embodiment 1. The only difference is that the fixed guide vane diffuser 11 in this embodiment converts kinetic energy into static pressure more efficiently, and can maintain aerodynamic efficiency in a high range even when the flow rate adjustment range is large. Therefore, this embodiment is suitable for operating conditions with a large flow rate adjustment range.

[0043] Example 3 Please refer to the following: Figure 7 The difference between this embodiment and Embodiment 1 is that the diffuser in this embodiment is an adjustable guide vane diffuser 12. That is, based on the bladeless diffuser 10 of Embodiment 1, 11 adjustable guide vanes are added. The 11 adjustable guide vanes are evenly distributed in a ring and form a rotating pair with the diffuser seat 21. The centrifugal blower in this embodiment works on the same principle as in Embodiment 1. The only difference is that the adjustable guide vane diffuser 12 in this embodiment has a wider efficient range for converting kinetic energy into static pressure. Even with a large flow rate adjustment range (40%~100%), it can maintain a high aerodynamic efficiency, ensuring good flow characteristics and improving flow efficiency under different operating conditions, thus improving adaptability to operating conditions.

[0044] Example 4 Please refer to the following: Figure 8 Based on Embodiment 1, this embodiment further discloses the adjustment structure of the inlet guide vane 17, which includes an electric actuator 22 mounted on the inner volute 8, a rotating ring 23, a guide bearing 24 fixed to the inner volute 8 by bolts, an eccentric sleeve 25 with an interference fit in the guide bearing 24, a ball 26 fixed on the rotating ring 23, a flat key 28 fixedly mounted at the end of the shaft of the inlet guide vane 17, and a shift fork 27 for connecting the ball 26 and the corresponding flat key 28.

[0045] In this embodiment, the guide bearing 24 has a W-shaped surface, which forms rolling friction with the rotating ring 23 to facilitate close contact between the guide bearing 24 and the rotating ring 23. The number of balls 26 is the same as the number of inlet guide vanes 17, and they correspond one-to-one. The balls 26 are located on the inner ring of the rotating ring 23. In this embodiment, the eccentric sleeve 25 serves to provide uniform support force to the rotating ring 23 from the multiple guide bearings 24.

[0046] In this embodiment, the electric actuator 22 drives the rotating ring 23 to rotate, and the ball 26 fixed to the rotating ring 23 rotates accordingly. At this time, the ball 26 drives the shift fork 27 to rotate, and the shift fork 27 drives the inlet guide vane 17 to rotate along its journal axis through the flat key 28, thereby synchronously adjusting multiple inlet guide vanes 17 to realize automated adjustment of the inlet flow rate, which is convenient and has high adjustment accuracy. It should be noted that a scale is also installed at the transmission shaft of the electric actuator 22 to indicate the rotation amplitude, thereby facilitating the control of the rotation angle of the inlet guide vane 17.

[0047] The above embodiments are merely preferred embodiments of the present invention. Any simple modifications, alterations, and substitutions made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A compact single-stage high-speed centrifugal blower, comprising a drive unit, a transmission unit, and a pneumatic unit, characterized in that: The drive unit includes a permanent magnet synchronous motor (1), and the transmission unit includes a transmission housing (3), a large gear (4) mounted on the motor shaft (2) of the permanent magnet synchronous motor (1), a driven shaft (5) mounted in the transmission housing (3) via two high-speed sliding bearings (19), and a small gear (6) meshing with the large gear (4); wherein the small gear (6) and the large gear (4) mesh to form a transmission pair, and a sliding bearing (18) is fixedly installed on the side wall of the transmission housing (3) facing the drive unit, the sliding bearing (18) and the motor shaft (2) form a rotating pair, and the driven shaft (5) and the high-speed sliding bearing (19) form a rotating pair.

2. The compact single-stage high-speed centrifugal blower according to claim 1, characterized in that: Two high-speed sliding bearings (19) are respectively installed on both sides of the transmission housing (3); In the permanent magnet synchronous motor (1), a cooling channel is provided in the mounting base for supporting the iron core and stator windings. The cooling channel has a circulating part (13) and a branch part (14). The circulating part (13) and the branch part (14) are connected, and the branch part (14) is located in the middle of the two connected stator windings.

3. The compact single-stage high-speed centrifugal blower according to claim 2, characterized in that: The permanent magnet synchronous motor (1) has an inlet and an outlet on its two end caps, respectively. The outlet is located near the transmission part, and both the inlet and outlet are connected to the cooling channel.

4. The compact single-stage high-speed centrifugal blower according to claim 3, characterized in that: The mounting base is provided with two heat-conducting plates (15), the rotor of the permanent magnet synchronous motor (1) is located between the two heat-conducting plates (15), and there is an air gap between the rotor and the heat-conducting plates (15); The heat-conducting plate (15) is circular and can be detachably mounted on the mounting base by screws. A through cavity for the motor shaft (2) is provided at the center of the heat-conducting plate (15).

5. The compact single-stage high-speed centrifugal blower according to claim 1, characterized in that: The permanent magnet synchronous motor (1) is fixedly installed on the corresponding side of the transmission housing (3), and one end of the motor shaft (2) extends into the transmission housing (3); The large gear (4) is fixed to the end of the motor shaft (2) by screws, and the small gear (6) is fixedly sleeved on the driven shaft (5).

6. The compact single-stage high-speed centrifugal blower according to claim 1, characterized in that: Two thrust discs (20) are fixedly sleeved on the driven shaft (5), and the meshing surfaces of the large gear (4) and the small gear (6) are located between the two thrust discs (20).

7. The compact single-stage high-speed centrifugal blower according to claim 1, characterized in that: The pneumatic unit includes a volute, an impeller (9) and a diffuser. The volute is fixedly installed on the opposite side of the transmission housing (3) and one end of the driven shaft (5) extends into the volute. The volute has an inner volute (8) and an outer volute (7).

8. The compact single-stage high-speed centrifugal blower according to claim 7, characterized in that: The impeller (9) is located in the inner volute (8) and is fixedly installed at the end of the driven shaft (5). A front cover (16) is provided on the side of the inner volute (8) facing away from the transmission box (3), and the front cover (16) and the inner volute (8) form an air intake channel. An air outlet channel is provided at a position of the volute away from the air intake channel. Several inlet guide vanes (17) are provided between the front cover (16) and the inner volute (8), and the several inlet guide vanes (17) are evenly distributed along the circumference in the air intake channel.

9. The compact single-stage high-speed centrifugal blower according to claim 8, characterized in that: The diffuser is a bladeless diffuser (10), wherein the diffuser seat (21) and the inner volute (8) form the bladeless diffuser (10).

10. The compact single-stage high-speed centrifugal blower according to claim 9, characterized in that: Alternatively, the diffuser is a fixed guide vane diffuser (11). Alternatively, the diffuser may be an adjustable guide vane diffuser (12).

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