Axial centrifugal gas pump
By using the threaded fit between the impeller cover and the motor frame of the axial centrifugal air pump and the axial contact of the guide tube, the problems of tip clearance leakage and non-compact structure are solved, achieving efficient tip clearance control and high pressure output, which is suitable for compact axial flow layouts.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YUNSHAN HIGH ENERGY (SHENZHEN) TECH CO LTD
- Filing Date
- 2025-04-30
- Publication Date
- 2026-06-23
AI Technical Summary
Existing centrifugal air pumps suffer from problems such as tip clearance leakage affecting aerodynamic efficiency, high cost, non-compact structure, and difficulty in achieving high pressure output and axial flow.
The axial centrifugal air pump adopts an axial centrifugal air pump structure. Through the threaded pair between the impeller cover and the motor frame, high-precision adjustment and locking of the blade tip gap are achieved. Combined with the axial contact between the guide tube and the impeller cover to generate pre-tightening force, the reliable locking and gap stability of the impeller cover under high-speed operation are ensured.
It achieves efficient tip clearance control at low cost, improves the working efficiency of the air pump, and has a compact structure that is easy to carry and use.
Smart Images
Figure CN224396714U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of centrifugal air pumps, and more particularly to an axial centrifugal air pump. Background Technology
[0002] Existing high-speed fan technology in the consumer electronics field is mature and cost-effective. However, due to the prevalence of axial impeller designs, while the air volume is large, the air pressure is relatively low, failing to meet the inflation pressure requirements of devices such as inflatable tents and boats, and also struggling to meet the suction needs of devices like storage bags and vacuum cleaners. While centrifugal impellers can achieve a high single-stage pressure ratio and generate sufficient air pressure, leakage at the impeller tip gap is a core issue severely impacting aerodynamic efficiency. Currently, the centrifugal compressor and vacuum cleaner industries often adopt solutions that improve component machining precision or use closed impellers. The former requires extremely high assembly precision, while the latter increases the machining difficulty of the impeller itself, both significantly increasing costs. Furthermore, industrial centrifugal air pumps often employ a volute structure, resulting in a large radial dimension and preventing a compact axial inlet / outlet layout, making them inconvenient for consumers to carry. Therefore, developing a compact centrifugal air pump that achieves low-cost, high-precision gap adjustment while balancing high pressure output and axial flow is a pressing technical problem to be solved in this field. Utility Model Content
[0003] In view of this, the present invention provides a structural solution for an axial centrifugal air pump to at least partially solve the technical problems mentioned in the background art.
[0004] This utility model provides an axial centrifugal air pump, including a motor frame, a centrifugal impeller, an impeller cover, a guide tube, and a tail nozzle. The motor frame has a rotor shaft, and the centrifugal impeller is mounted on the rotor shaft. The front end of the motor frame is provided with a first threaded portion, and the impeller cover is screwed to the motor frame through the first threaded portion. By rotating the impeller cover, its axial relative position with respect to the centrifugal impeller is changed, thereby adjusting the tip clearance between the impeller cover and the centrifugal impeller. The guide tube is fitted and connected to the outer surface of the motor frame and fixed to the motor frame by a second connecting structure. The tail nozzle is installed at the outlet end of the guide tube. When the impeller cover is adjusted to a preset position, one end face of the impeller cover abuts against the end face of the guide tube and generates axial pressure, so that the guide tube and the impeller cover form a locking structure.
[0005] Optionally, the motor frame can be a mature high-speed motor frame. By replacing the original axial impeller with a centrifugal impeller and adding the impeller cover, a highly efficient centrifugal compression effect can be achieved while maintaining a compact size.
[0006] Optionally, the second connection structure is selected from at least one of threaded connection, interference fit, or adhesive fixation; the inner surface of the guide tube and the outer surface of the motor frame are adapted to each other and tightly fitted. When the second connection structure is a threaded connection, the axial pressure between the end faces of the guide tube and the impeller cover can be adjusted by rotating the guide tube or the impeller cover to achieve mutual locking. When the second connection structure is an interference fit, the guide tube is pressed into the motor frame by a predetermined distance, and the impeller cover is rotated to press the guide tube tightly to achieve locking. When the second connection structure is adhesive fixation, the guide tube is installed into the motor frame until it contacts the impeller cover, and the assembly position is maintained by adhesive curing, thereby achieving the fixed locking of the guide tube and the impeller cover.
[0007] Optionally, the inner wall of the impeller cover is provided with an internal thread that matches the first threaded portion; the inner side of the impeller cover has an inner plane, and the centrifugal impeller has a blade tip; by rotating the impeller cover to move it axially along the motor frame, the blade tip gap between the inner plane of the impeller cover and the blade tip can be adjusted. Thread adhesive can also be used between the impeller cover and the motor frame to enhance the fixing effect.
[0008] Optionally, the locking structure includes an impeller cover end face located on the opening side of the impeller cover and a guide tube end face located at one end of the guide tube; after the impeller cover is screwed onto the motor frame and adjusted to a preset blade tip gap position, the guide tube is moved axially along the motor frame through the second connecting structure until the guide tube end face abuts against the impeller cover end face and generates axial pressure, thereby achieving axial locking of the impeller cover.
[0009] Optionally, the motor frame is provided with an inner flow channel; the gas generated and driven by the centrifugal impeller is guided by the inner plane of the impeller cover inside the impeller cover, changing from radial flow to axial flow, and flows through the inner flow channel.
[0010] The beneficial effects of this utility model are as follows: By using the threaded joint between the impeller cover and the motor frame, this utility model achieves high-precision control of the blade tip clearance through axial displacement compensation during assembly, under relatively low component machining tolerance requirements. Simultaneously, the axial contact between the guide tube end face and the impeller cover end face generates a pre-tightening force, ensuring reliable locking and clearance stability of the impeller cover under high-speed operating conditions. This structure is simple, easy to assemble, significantly improves the working efficiency of the centrifugal air pump, and achieves a compact axial inlet and outlet layout, greatly facilitating consumer portability and use. Attached Figure Description
[0011] Further details, features, and advantages of the present invention will be disclosed in the following description of exemplary embodiments taken in conjunction with the accompanying drawings. In the drawings:
[0012] Figure 1 This diagram shows the exploded structure of the axial centrifugal air pump provided by this utility model. Figure 1 ;
[0013] Figure 2 This diagram shows the exploded structure of the axial centrifugal air pump provided by this utility model. Figure 2 The main focus is on showcasing the internal structure and rear end of the impeller cover;
[0014] Figure 3 This diagram shows an overall assembly perspective view of the axial centrifugal air pump provided by this utility model. Detailed Implementation
[0015] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.
[0016] It should be understood that the steps described in the method embodiments of this application may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this application is not limited in this respect.
[0017] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; and the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below. It should be noted that the concepts of "first," "second," etc., mentioned in this application are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.
[0018] Please refer to Figures 1 to 3 This embodiment provides an axial centrifugal air pump, which includes a motor frame 10, a centrifugal impeller 20, an impeller cover 30, a guide tube 40, a circuit board 50, and a tail nozzle 60. The motor frame 10 internally includes a motor stator 15, a rotating rotor shaft 17, a stator fixing bracket 16, and an internal airflow channel 13. The front end of the motor frame 10 has a first threaded portion 11 and a front end face 18, and its rear end has a rear end portion 12. The circuit board 50 is mounted on the rear end of the motor frame 10, and the circuit board 50 has an external interface; in this embodiment, a Type-C interface is used as an example.
[0019] Combination Figure 1 and Figure 2 As shown, the impeller cover 30 has an internal thread 34 at its rear end for screwing with the first threaded portion 11. The impeller cover 30 has an impeller cover inlet 31 at its front end, with an inner impeller cover plane 33 inside. An annular impeller cover end face 32 is provided at the rear opening side of the impeller cover 30. The guide tube 40 has a guide tube end face 41 at its front end and a positioning feature 43 at its rear end. The tail nozzle 60 has a positioning structure 61.
[0020] First, install the centrifugal impeller 20 on the rotor shaft 17:
[0021] In one example, the centrifugal impeller 20 and the rotor shaft 17 are press-fitted together. The centrifugal impeller 20 is pressed into a predetermined position along the rotor shaft 17. An auxiliary fixture is used to ensure that the tip 21 of the centrifugal impeller 20 is at a predetermined height (e.g., 2mm) from the front end face 18 of the motor frame 10. This distance does not need to be precisely controlled; approximately 2mm is sufficient. In another example, the rotor shaft 17 and the centrifugal impeller 20 are clearance-fitted together with auxiliary adhesive. Similarly, the centrifugal impeller 20 is pressed into the rotor shaft 17 at a height of approximately 2mm from the tip 21 of the centrifugal impeller 20 to the front end face 18 of the motor frame 10. After the adhesive dries, the impeller is fixed.
[0022] Next, install the impeller cover 30 onto the motor frame 10:
[0023] In conventional practices, the impeller cover and motor frame typically use a stop fit to ensure accurate positioning. Furthermore, the assembly process requires precision fixtures to strictly control multiple relative dimensions of the centrifugal impeller 20 relative to the front end face 18 and the impeller cover 30 relative to the front end face 18. Because multiple relative dimensions need to be guaranteed, the assembly process is highly demanding, sometimes involving repeated disassembly and adjustment, which increases mass production costs.
[0024] In this embodiment, the distance between the blade tip 21 and the front end face 18 of the motor frame does not need to be precisely controlled; it can be achieved simply by using an auxiliary fixture or by utilizing the inner ring of the bearing on the rotor shaft 17 for obstruction during installation. The blade tip clearance is controlled by rotating the impeller cover 30, and the following three locking and clearance control methods are provided based on the different connection characteristics of the rear end 12:
[0025] Example 1: The guide tube 40 is connected to the motor frame 10 by threads.
[0026] At this point, the rear end 12 of the motor frame 10 is provided with a second threaded portion. During assembly, without first installing the guide tube 40, screw the impeller cover 30 into the first threaded portion 11 until the inner plane 33 of the impeller cover contacts the blade tip 21, at which point the blade tip clearance is equivalent to 0mm. Continuing to rotate the impeller cover 30 will generate axial pressure from the surface 33 on the surface 21, at which point the centrifugal impeller 20 will obviously rotate with the impeller cover 30. When it is found that the centrifugal impeller 20 tends to rotate with the impeller cover 30, it is determined as a contact signal and the rotation of the impeller cover 30 is stopped. Then, install the guide tube 40 and screw it into the rear end 12 until the end face 41 of the guide tube contacts the end face 32 of the impeller cover. Continuing to rotate the guide tube 40 will generate axial pressure perpendicular to the surface 32 of the impeller cover 30, which has a tendency to push the impeller cover 30 away from the centrifugal impeller 20, causing the surface 33 to slightly move away from the blade tip 21. This ensures a very small blade tip clearance without affecting the rotation of the centrifugal impeller 20, and also achieves the locking of the impeller cover 30.
[0027] Example 2: The guide tube 40 is interference-fitted with the motor frame 10.
[0028] At this point, the rear end 12 of the motor frame 10 is not threaded. During assembly, the impeller cover 30 is not installed initially. Using a jig, the guide tube 40 (which has an internal cavity 44 and positioning features 43) is pressed in from the rear end 12 to a rough distance from the front end face 18, such as 2mm. This distance does not need to be precise. Then, the impeller cover 30 is screwed onto the motor frame 10 until its impeller cover end face 32 contacts the guide tube end face 41. At this point, the blade tip 21 and the inner plane 33 of the impeller cover are still not in contact. Continuing to rotate the impeller cover 30 will generate axial pressure on the guide tube end face 41, and the thread pull will cause the motor frame 10 to move the centrifugal impeller 20 towards the impeller cover 30, thus generating axial relative displacement and "pulling" the motor frame 10. At this point, a plug of a preset thickness (e.g., 0.01 mm) is inserted between the blade tip 21 and 33 surfaces from the impeller cover inlet 31 until the blade tip 21 presses against the plug. Then, the rotation stops and the plug is removed, thus achieving locking and precise control of the blade tip gap.
[0029] Example 3: The guide tube 40 is fitted with the motor frame 10 with clearance and is assisted by adhesive bonding.
[0030] At this point, the rear end 12 of the motor frame 10 is smooth. During assembly, do not install the guide tube 40 initially. Rotate the impeller cover 30 until a contact signal is generated that the centrifugal impeller 20 follows (equivalent gap 0mm), then stop rotating. Rotate the impeller cover 30 in the opposite direction by a certain angle (e.g., 36 degrees). The gap will then be 1 / 10 of the pitch of the first threaded portion 11. For example, if the pitch is 0.5mm, the gap will be 0.05mm. Then, apply adhesive to the inner wall of the guide tube 40 and push it in along the rear end 12 until its guide tube end face 41 contacts the impeller cover end face 32.
[0031] At this point, the device is held upright with the impeller cover 30 facing upwards. Under the influence of gravity, the motor frame 10 and the centrifugal impeller 20 tend to fall downwards relative to the guide tube 40. Since the guide tube 40 provides support, gravity automatically pulls the impeller cover end face 32 and the guide tube end face 41 together, locking them in a locked state. Simultaneously, the excess adhesive between the motor frame 10 and the guide tube 40 further secures the impeller cover 30. After the adhesive dries, the impeller cover 30 is completely fixed to all components.
[0032] Regarding the logic for fixing the tail position:
[0033] like Figure 1 and Figure 2 As shown, both the positioning feature 43 of the guide tube 40 and the positioning structure 61 of the tail nozzle 60 are semi-circular notches. In the assembled state, the positioning feature 43 and the positioning structure 61 are engaged (interlocked) and together fitted onto the outer periphery of the external interface of the circuit board 50. Using the external interface as a physical reference, axial positioning and fixation between the guide tube 40 and the tail nozzle 60 are achieved, and due to the obstruction of the interface shape, circumferential relative rotation or misalignment between the guide tube 40 and the tail nozzle 60 is effectively prevented.
[0034] After assembly, as follows Figure 3 As shown, the centrifugal impeller 20 rotates to drive the airflow. The airflow is guided and turned by the inner plane 33 of the impeller cover, enters the inner flow channel 13 inside the motor frame 10, and is finally discharged from the tail nozzle 60.
[0035] In summary, this embodiment provides at least three installation methods, all of which can effectively achieve precise control of the blade tip clearance. It should be understood that the device is named an axial centrifugal air pump based on the tail nozzle 60 being the outlet end; when the impeller cover inlet 31 is used as the inlet end, it can also be applied to scenarios such as dust collection or vacuum pumping. The processing methods and specific values provided in this embodiment are merely illustrative and should not adversely limit the scope of protection. The patent protection scope of this application embodiment should be defined by the claims.
Claims
1. An axial centrifugal air pump, comprising a motor frame (10), a centrifugal impeller (20), an impeller cover (30), a guide tube (40), and a tail nozzle (60), characterized in that: The motor frame (10) has a rotor shaft (17), and the centrifugal impeller (20) is mounted on the rotor shaft (17). The front end of the motor frame (10) is provided with a first threaded portion (11), and the impeller cover (30) is screwed onto the motor frame (10) through the first threaded portion (11). By rotating the impeller cover (30) to change its axial relative position with respect to the centrifugal impeller (20), the relationship between the impeller cover (30) and the centrifugal impeller (20) can be adjusted. The blade tip gap; the guide tube (40) is attached to the outer surface of the motor frame (10) and is axially adjustable to the motor frame (10) through the second connection structure; the tail nozzle (60) is installed at the outlet end of the guide tube (40); when the impeller cover (30) is adjusted to the preset position, one end face of the impeller cover (30) abuts against the end face of the guide tube (40) and generates axial pressure, so that the guide tube (40) and the impeller cover (30) form a locking structure.
2. The axial centrifugal air pump according to claim 1, characterized in that, The second connection structure is selected from at least one of threaded connection, interference fit or adhesive fixation; the inner surface of the guide tube (40) is adapted to and closely fitted with the outer surface of the motor frame (10).
3. The axial centrifugal air pump according to claim 1, characterized in that, The inner wall of the impeller cover (30) is provided with an internal thread (34) that matches the first threaded part (11); the inner side of the impeller cover (30) has an inner plane (33), and the centrifugal impeller (20) has a blade tip (21); by rotating the impeller cover (30) to move it axially along the motor frame (10), the blade tip gap between the inner plane (33) of the impeller cover and the blade tip (21) can be adjusted.
4. The axial centrifugal air pump according to claim 1, characterized in that, The locking structure includes: an impeller cover end face (32) located on the opening side of the impeller cover (30), and a guide tube end face (41) located at one end of the guide tube (40); when the impeller cover (30) is screwed onto the motor frame (10) and adjusted to the preset blade tip gap position, the guide tube (40) is moved axially along the motor frame (10) through the second connecting structure until the guide tube end face (41) abuts against the impeller cover end face (32) and generates axial pressure, so as to lock the impeller cover (30).
5. The axial centrifugal air pump according to claim 3, characterized in that, The motor frame (10) is provided with an inner flow channel (13); the gas generated and propelled by the centrifugal impeller (20) is guided by the inner plane (33) of the impeller cover (30) inside the impeller cover (30), changes from radial flow to axial flow, and flows through the inner flow channel (13).