Split type backpack variable-frequency shield pump
The split backpack variable frequency shielded pump addresses maintenance challenges by enabling external replacement of the control module, enhancing efficiency and reducing downtime through a split control box design.
Patent Information
- Application Number
- CN202420501556.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-14
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-03-14
AI Technical Summary
Existing variable frequency canned pumps require complex maintenance, leading to high costs and low reuse rates due to the need to remove the entire pump from the pipeline for repairs, which is difficult and inefficient.
A split backpack variable frequency shielded pump design separates the variable frequency control module from the motor structure using a split control box, allowing external replacement of the control module without removing the entire pump, facilitated by external connections and stable support structures.
This design enhances maintenance efficiency, reduces downtime, allows for quick pipeline restoration, and enables recycling or repair of the control module, improving operational stability and reducing maintenance costs.
Smart Images
Figure CN222185121U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a shielded pump, in particular to a split-type backpack variable frequency shielded pump with a backpack control structure. Background Art
[0002] The existing variable frequency canned pump (variable frequency booster pump) includes a motor, a pump body matched with the motor, and a control part arranged on the motor. For the variable frequency canned pump, the motor and the pump body and other structures are required to have higher reliability. Once the variable frequency canned pump fails, the whole pump is usually removed from the pipeline for maintenance. This maintenance method has high requirements for maintenance personnel, there are more difficulties during maintenance, and the reuse rate after maintenance is low, resulting in high maintenance costs. Summary of the invention
[0003] The purpose of the utility model is to solve the above-mentioned problems existing in the prior art and to provide a split backpack variable frequency shielded pump, in which the variable frequency control module is separated from the motor structure by a split control box, and the variable frequency control module is connected to the motor casing from the outside in the form of a backpack. When the variable frequency control module fails, there is no need to remove the entire pump from the pipeline. Only the variable frequency control module needs to be removed and replaced with a new one. The maintenance efficiency is extremely high, and the time occupied for normal use of the pipeline is reduced. The pipeline can be quickly restored to normal use. At the same time, the replaced variable frequency control module can be recycled or repaired and replaced with parts for the next replacement use.
[0004] The above technical purpose of the utility model is mainly solved by the following technical solutions: a split backpack variable frequency shielded pump, including a pump body, a motor connected to the pump body and driving the impeller assembly in the pump body to work, characterized in that the motor is arranged horizontally, the pump body is arranged at the driving end of the motor, and a variable frequency control module is arranged above the motor, the variable frequency control module includes a control box with an open top, an aluminum cover covering the open end of the control box and connected to the control box through a connecting piece, a plurality of heat sinks are arranged on the side of the aluminum cover facing away from the control box, the control board in the variable frequency control module is fixed on the aluminum cover and accommodated in the control box, and the control box is connected to the casing of the motor through a connecting piece. The frequency conversion control module is separated from the motor structure through a split control box, and the frequency conversion control module is connected to the motor casing from the outside in the form of a backpack. When the frequency conversion control module fails, there is no need to remove the entire pump from the pipeline. Only the frequency conversion control module needs to be removed and replaced with a new one. The maintenance efficiency is extremely high, and the time occupied for normal use of the pipeline is reduced. The pipeline can be quickly restored to normal use. At the same time, the replaced frequency conversion control module can be recycled or repaired and replaced with parts for the next replacement use.
[0005] As a further improvement and supplement to the above technical solution, the utility model adopts the following technical measures: two downwardly extending fixing feet are arranged at the bottom of the control box, the fixing feet are clamped on both sides of the width direction of the motor, and the fixing feet are fixed to the housing through the corresponding fixing feet and the corresponding connecting holes on the housing from the outside to the inside through the transversely connected connecting piece, and the tool operation end of the connecting piece is exposed. The technical purpose of this technical solution is to facilitate the disassembly or assembly of the frequency conversion control module from the outside, and to operate from the housing of the motor or the external space of the frequency conversion control module.
[0006] In order to more conveniently and stably fix the frequency conversion control module and ensure convenient disassembly or assembly through the external space, a motor flange is arranged on the motor, and a pump body flange is arranged on the pump body. The motor flange is fitted with the pump body flange and axially connected through a connecting piece. The fixing feet are respectively clamped and fixed on both sides of the motor flange. A casing fixing foot is arranged at the bottom of the control box corresponding to the end of the motor away from the pump body. An external convex connecting ear is arranged on the casing, and a connecting piece passes through the external convex connecting ear and the casing fixing foot from bottom to top and is fixed.
[0007] A second cable outlet is provided in the upper middle part of the motor flange, and is provided so that the cable inside the motor passes through the second cable outlet and enters the control box through the corresponding threading hole on the control box to form an electrical connection with the control board. In order to make the control box have a certain size specification, the length of the control box is generally adapted to the length of the motor housing. The second cable outlet is provided on the flange, which can conveniently connect the control box in a positive direction to form a connection with the control board inside the control box, reduce the wiring distance, avoid wiring bending, and is conducive to protecting the cable, improving the service life and safety of use.
[0008] A grounding threaded hole is provided on the upper side of the motor flange, and the grounding wire inside the motor cooperates with the grounding threaded hole to form a grounding connection. The grounding threaded hole avoids the second cable outlet to avoid interference between the two and facilitate operation.
[0009] In order to increase the internal space of the control box, it extends outward in the width direction of the motor. Therefore, the width of the control box is greater than the width of the housing. The control box forms an extension portion on the outside of the housing. The extension portion is provided with a first cable outlet. The first cable outlet avoids the housing and is used for the cable to enter the control box to form an electrical connection and a signal connection with the control board. The first cable outlet avoids the housing, which is convenient for operators to install and set the cable, and allows the cable to smoothly extend outward to form a connection with an external line.
[0010] In order to enable the horizontally placed motor to stand stably, a base is provided at the bottom of the motor, and a pair of supporting structures are provided on the base. The supporting structures are supported on both sides of the bottom of the motor and clamp both sides of the casing. Diagonal reinforcing ribs are provided on both sides of each supporting structure. The shape and size of the diagonal reinforcing ribs provided corresponding to the casing are adapted to the shape and size of the gap formed between the casing and the supporting structure. There is no special regulation for the size of the diagonal reinforcing ribs located on the outside of the motor. The diagonal reinforcing ribs are provided in a manner of maximum strength under the premise of reasonable layout and reasonable consumption of raw materials. The diagonal reinforcing ribs provided on the inside fully match the external contour of the motor casing so that the weight of the motor can be supported on the base, and the diagonal reinforcing ribs are provided in a manner of maximum strength to increase the clamping force and supporting force of the supporting structure, so that the motor can be stably provided on the base.
[0011] In order to make the strength of the support structure appropriate and to achieve the function of supporting and clamping the motor, the upper end of the base has a certain width, and a rib groove is set at the upper end of the base. The rib groove is set along the direction of the heat dissipation rib on the housing, and the heat dissipation rib at the corresponding position is embedded in the rib groove. The setting of the rib groove is not only conducive to embedding the heat dissipation rib, but also reasonable external dimensions of the entire variable frequency pump, making it compact. At the same time, the rib groove can play the role of stopping rotation and positioning.
[0012] The base is provided with a rear support boss and a front support boss, and the rear support boss and the front support boss are provided in the middle of the area surrounded by a pair of the support structures, and at least two first waist-shaped connection holes arranged at intervals are provided on the rear support boss, and a second waist-shaped connection hole is provided on the front support boss, corresponding to the positions of the first waist-shaped connection hole and the second waist-shaped connection hole, and the bottom of the housing is provided with corresponding connecting waist-shaped holes, and the connecting member passes through the first waist-shaped connection hole and the second waist-shaped connection hole from the bottom to the top from the bottom surface of the base to enter the lower part of the motor for connection. The arrangement of the rear support boss and the front support boss is conducive to making the heat dissipation ribs on the motor penetrate into the space surrounded by the rear support boss, the front support boss and the base body, and further rationalizes the external dimensions of the entire variable frequency pump to make it compact. Since the length of the heat dissipation rib on the motor casing is smaller than the length of the motor casing, there are indented parts at both ends of the motor casing, and connecting holes are set in the indented parts of the motor casing. The rear supporting boss and the front supporting boss are respectively supported on the indented parts. The indented parts on the motor casing have better supporting strength than the heat dissipation rib parts. The heat dissipation ribs are easily deformed under heavy pressure. Therefore, the rear supporting boss and the front supporting boss are supported on the indented parts to improve the connection reliability and facilitate the setting of connecting holes in the indented parts. The connecting parts pass through the base from the bottom of the base and enter the connecting holes on the motor casing to form a connection, so that surface contact is formed between the rear supporting boss and the front supporting boss respectively, avoiding line contact of the heat dissipation ribs, so that the support and connection are reliable and stable.
[0013] The utility model has the following beneficial effects: 1. The frequency conversion control module is separated from the motor structure through a split control box, and the frequency conversion control module is connected to the motor casing from the outside in the form of a backpack. When the frequency conversion control module fails, there is no need to remove the entire pump from the pipeline. Only the frequency conversion control module needs to be removed and replaced with a new one. The maintenance efficiency is extremely high, and the time occupied for normal use of the pipeline is reduced. The pipeline can quickly resume normal use. At the same time, the replaced frequency conversion control module can be recycled or repaired and replaced with parts for the next replacement. 2. The connection between the frequency conversion control module and the casing is an external connection method. Through lugs, connecting feet, etc., the connection part is extended to a relatively open area, which is convenient for operators to operate the connecting parts and complete the disassembly and assembly of the frequency conversion control module, which is convenient for operation and improves disassembly and assembly efficiency. 3. Change the structure of the motor base. The support structure on the base clamps and supports both sides of the motor. The support structure can provide clamping and support functions, and can also position and stop the casing, which is convenient for operating the connector. The connection and fixing method is formed by the boss structure on the base at both ends of the motor to form a surface contact. It can also avoid and accommodate the heat dissipation ribs on the casing, making the overall structure of the variable frequency pump more compact, so as to reduce the overall volume, thereby increasing the applicability and convenience of the variable frequency pump. 4. The control box is a plastic part. The control board and the motor assembly are isolated by the plastic control box, which can avoid the heating of the motor and affect the normal use of the control board, so that the control board can operate more stably, avoid heat affecting the operation stability, and increase the service life; 5. The aluminum cover has a certain strength, which is conducive to protecting the variable frequency control module. At the same time, the aluminum cover is also a good conductor of heat, which is convenient for quickly dissipating the heat generated by the control board. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a structural schematic diagram of the utility model.
[0015] Figure 2 and Figure 3 They are Figure 1 Schematic diagram of the structure from different perspectives.
[0016] In the figure: 1. pump body; 2. motor; 3. frequency conversion control module; 4. control box; 5. aluminum cover; 6. heat sink; 7. control board; 8. connecting lug; 9. first cable outlet; 10. fixing foot; 11. motor flange; 12. pump body flange; 13. second cable outlet; 14. threading port; 15. grounding mounting threaded hole; 16. supporting structure; 17. oblique reinforcement rib; 18. rib groove; 19. heat dissipation rib; 20. rear support boss; 21. front support boss; 22. connecting lug; 23. cable connector; 24. base. DETAILED DESCRIPTION
[0017] The technical solution of the utility model is further specifically described below through embodiments and in conjunction with the accompanying drawings.
[0018] Example: Figure 1-3 As shown, the split backpack variable frequency shielded pump comprises a pump body 1, and a horizontally arranged motor 2 connected to the pump body 1 and driving the impeller assembly in the pump body 1. The pump body 1 is arranged at the driving end of the motor 2, and a variable frequency control module 3 is arranged above the motor 2. The variable frequency control module 3 comprises a control box 4 with an upper opening, an aluminum cover 5 covering the open end of the control box 4 and connected to the control box 4 through a connector, and a plurality of heat sinks 6 are arranged on the side of the aluminum cover 5 facing away from the control box 4. The control board 7 in the variable frequency control module 3 is fixed on the aluminum cover 5 and accommodated in the control box 4, and the control box 4 is connected to the housing of the motor 2 through a connector.
[0019] Among them, the control box 4 is a plastic part, and the control board 7 and the motor 2 components are isolated by the control box 4 of the plastic part, which can prevent the motor 2 from heating up and affecting the normal use of the control board 7, so that the control board 7 can operate more stably, avoid being affected by heat and affecting the operating stability, and increase the service life. The aluminum cover 5 has a certain strength, which is beneficial to protecting the frequency conversion control module 3. At the same time, the aluminum cover 5 is also a good conductor of heat, which is convenient for quickly dissipating the heat generated by the control board 7, and is also beneficial for the control board 7 to operate more stably and increase the service life of the control board 7.
[0020] The control box 4 and the aluminum cover 5 are both provided with connecting lugs 8 on their exteriors, which are used to set connecting pieces to connect and fix the control box 4 and the aluminum cover 5. The connection lugs 8 are provided to avoid occupying the local space of the control box 4 and the aluminum cover 5, and to ensure that the control box 4 has enough space to set the control board 7, and at the same time, it is also beneficial to save the raw materials for producing the control box 4 and the aluminum cover 5, and reduce the production cost.
[0021] Next, in order to increase the internal space of the control box 4, it extends outward in the width direction of the motor 2. Therefore, the width of the control box 4 is greater than the width of the housing. The control box 4 forms an extension portion on the outside of the housing, and a first cable outlet 9 is provided on the extension portion (a cable connector 23 is provided at the first cable outlet 9). The first cable outlet 9 (the outlet can pass the cable and the signal line at the same time) avoids the housing, and is used for the cable (or the cable and the signal line) to enter the control box 4 and form an electrical connection (or an electrical connection and a signal connection) with the control board 7. The first cable outlet 9 avoids the housing, which is convenient for operators to install and set the cable, and allows the cable to smoothly extend outward, so as to form a connection with the external line.
[0022] In the above technical solution, the frequency conversion control module 3 is separated from the motor 2 structure by a split control box 4, and the frequency conversion control module 3 is connected to the casing of the motor 2 from the outside in the form of a backpack. When the frequency conversion control module 3 fails, there is no need to remove the entire pump from the pipeline. Only the frequency conversion control module 3 is removed and replaced with a new frequency conversion control module 3. The maintenance efficiency is extremely high, and the time occupied for normal use of the pipeline is reduced. The pipeline can quickly resume normal use. At the same time, the replaced frequency conversion control module 3 can be recycled or repaired and replaced with parts for the next replacement use.
[0023] To further improve the above technical solution, two downwardly extending fixing feet 10 are provided at the bottom of the control box 4, and the fixing feet 10 are clamped on both sides of the width direction of the motor 2, and the fixing feet 10 are fixed to the housing through the corresponding fixing feet 10 and the corresponding connecting holes on the housing through the connecting pieces that are horizontally connected (i.e., the connecting line of the connecting pieces on the two fixing feet 10 is parallel and perpendicular to the axis of the motor 2), and the fixing feet 10 are fixed to the housing, and the tool operation end of the connecting piece is exposed. The technical purpose of this technical solution is to facilitate the disassembly or assembly of the frequency conversion control module 3 from the outside, and to operate from the housing of the motor 2 or the external space of the frequency conversion control module 3.
[0024] In order to more conveniently and stably fix the frequency conversion control module 3 and ensure convenient disassembly or assembly through the external space, a motor flange 11 is arranged on the motor 2, and a pump body flange 12 is arranged on the pump body 1. The motor flange 11 is fitted with the pump body flange 12 and axially connected through a connecting piece. The fixing feet 10 are respectively clamped and fixed on both sides of the motor flange 11. The bottom of the control box 4 is provided with a casing fixing foot 10 corresponding to the end of the motor 2 away from the pump body 1. An external protruding connecting ear 22 is arranged on the casing, and a connecting piece passes through the external protruding connecting ear 22 and the casing fixing foot 10 from bottom to top and is fixed.
[0025] In order to protect the cable, a second cable outlet 13 is provided in the upper middle part of the motor flange 11, and the cable inside the motor 2 is passed out through the second cable outlet 13 and enters the control box 4 through the corresponding threading hole 14 on the control box 4 to form an electrical connection with the control board 7. In order to make the control box 4 have a certain size specification, the length of the control box 4 is generally adapted to the casing length of the motor 2. The second cable outlet 13 is provided on the motor flange 11, which can conveniently connect the control box 4 in the forward direction to form a connection with the control board 7 in the control box 4, reduce the wiring distance, avoid wiring bending, and is conducive to protecting the cable, improving the service life and safety of use.
[0026] To further improve the solution, in order to avoid the second cable outlet 13, prevent the grounding installation threaded hole 15 from interfering with the second cable outlet 13, and facilitate operation, a grounding installation threaded hole 15 is set on the upper side of the motor flange 11, and the grounding wire inside the motor 2 is matched with the grounding installation threaded hole 15 to form a grounding connection.
[0027] The above technical solution mainly improves the control box 4, the aluminum cover 5 and the housing of the motor 2, while the following technical solution is a solution for the coordination between the base and the housing of the motor 2 based on the above technical solution:
[0028] Specifically, in order to enable the horizontally placed motor 2 to stand stably, a base 24 is provided at the bottom of the motor 2, and a pair of support structures 16 are provided on the base. The support structures 16 are supported on both sides of the bottom of the motor 2 and clamp both sides of the housing. Both sides of each support structure 16 are provided with diagonal reinforcement ribs 17. The shape and size of the diagonal reinforcement ribs 17 corresponding to the housing are adapted to the shape and size of the gap formed between the housing and the support structure 16. The size of the diagonal reinforcement ribs 17 located on the outside of the motor 2 is not specifically specified. The diagonal reinforcement ribs 17 are provided in a manner of maximum strength under the premise of reasonable layout and reasonable consumption of raw materials. The diagonal reinforcement ribs 17 provided on the inside fully match the outer contour of the motor housing, so that the weight of the motor 2 can be supported on the base, and the diagonal reinforcement ribs 17 are provided in a manner of maximum strength to improve the clamping force and supporting force of the support structure 16, so that the motor 2 is stably provided on the base.
[0029] In order to make the strength of the support structure 16 appropriate and to achieve the function of supporting and clamping the motor 2, the upper end of the base has a certain width, and a rib groove 18 is provided on the upper end of the base. The rib groove 18 is provided along the direction of the heat dissipation rib 19 on the housing, and the heat dissipation rib 19 at the corresponding position is embedded in the rib groove 18. The provision of the rib groove 18 is not only conducive to embedding the heat dissipation rib 19, but also reasonable external dimensions of the entire variable frequency pump to make it compact. At the same time, the rib groove 18 can play the role of stopping rotation and positioning.
[0030] The base is provided with a rear support boss 20 and a front support boss 21, which are arranged in the middle of the area surrounded by a pair of the support structures 16, and at least two first waist-shaped connection holes arranged at intervals are arranged on the rear support boss 20, and a second waist-shaped connection hole is arranged on the front support boss 21, corresponding to the positions of the first waist-shaped connection hole and the second waist-shaped connection hole, and the bottom of the housing is provided with corresponding connecting waist-shaped holes, and the connecting member passes through the first waist-shaped connection hole and the second waist-shaped connection hole from the bottom to the top from the bottom surface of the base to enter the lower part of the motor 2 for connection. The arrangement of the rear support boss 20 and the front support boss 21 is conducive to making the heat dissipation ribs 19 on the motor 2 penetrate into the space surrounded by the rear support boss 20 and the front support boss 21 and the base body, further rationalizing the external dimensions of the entire variable frequency pump and making it compact.
[0031] There are at least one or two schemes for setting the heat dissipation rib 19 on the motor. The first scheme: the length of the heat dissipation rib 19 on the motor casing is less than the length of the motor casing, and there are indented parts at both ends of the motor casing. Connecting holes are set in the indented parts of the motor casing, and the rear supporting boss 20 and the front supporting boss 21 are respectively supported on the indented parts. The indented parts on the motor casing have better supporting strength than the heat dissipation rib 19 parts. The heat dissipation rib 19 is easily deformed under heavy pressure. Therefore, the rear supporting boss 20 and the front supporting boss 21 are supported on the indented parts to improve the connection reliability and facilitate the setting of connecting holes in the indented parts. The connecting piece passes through the base from the bottom of the base and enters the connecting hole on the motor casing to form a connection, so that surface contact is formed between the rear supporting boss 20 and the front supporting boss 21, respectively, to avoid line contact of the heat dissipation rib 19, so that the support and connection are reliable and stable. The second solution: the heat dissipation ribs 19 on the motor housing are arranged on the housing according to a certain pattern, and there is a blank area for the heat dissipation ribs on the motor housing. The rear support boss 20 and the front support boss 21 are respectively supported in the blank area for the heat dissipation ribs to avoid the heat dissipation ribs.
[0032] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. In the above embodiments, the utility model can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.
Claims
1. A split-type backpack variable frequency shielded pump, comprising a pump body (1), a motor (2) connected to the pump body (1) and driving an impeller assembly in the pump body (1), characterized in that The motor (2) is arranged horizontally, a pump body (1) is arranged at the driving end of the motor (2), a frequency conversion control module (3) is arranged above the motor (2), the frequency conversion control module (3) comprises a control box (4) with an open top, an aluminum cover (5) covering the open end of the control box (4) and connected to the control box (4) via a connecting piece, a plurality of heat sinks (6) are arranged on a side of the aluminum cover (5) facing away from the control box (4), a control board (7) in the frequency conversion control module (3) is fixed on the aluminum cover (5) and accommodated in the control box (4), and the control box (4) is connected to the housing of the motor (2) via a connecting piece.
2. The split backpack variable frequency canned pump according to claim 1 is characterized in that Two downwardly extending fixing feet (10) are provided at the bottom of the control box (4), and the fixing feet (10) are clamped on both sides of the width direction of the motor (2), and a transversely connected connecting piece passes through the corresponding fixing feet (10) and the corresponding connecting hole on the casing from the outside to the inside, so that the fixing feet (10) are fixed on the casing, and the tool operation end of the connecting piece is exposed.
3. The split backpack variable frequency canned pump according to claim 2 is characterized in that The motor (2) is provided with a motor flange (11), and the pump body (1) is provided with a pump body flange (12); the motor flange and the pump body flange are attached to each other and are axially connected via a connecting piece; and the fixing feet (10) are respectively clamped and fixed on both sides of the motor flange.
4. The split backpack variable frequency canned pump according to claim 3 is characterized in that A casing fixing foot (10) is provided at the bottom of the control box (4) corresponding to the end of the motor (2) facing away from the pump body (1), and an external convex connecting ear (22) is provided on the casing. A connecting piece passes through the external convex connecting ear (22) and the casing fixing foot (10) from bottom to top and is fixed.
5. The split backpack variable frequency canned pump according to claim 4 is characterized in that A second cable outlet (13) is provided at the upper middle portion of the motor flange, and is arranged so that the cable inside the motor (2) passes through the second cable outlet (13) and enters the control box (4) through a corresponding threading port (14) on the control box (4) to form an electrical connection with the control board (7).
6. The split backpack variable frequency canned pump according to claim 5 is characterized in that A grounding installation threaded hole (15) is provided at the upper side of the motor flange, and a grounding wire inside the motor (2) cooperates with the grounding installation threaded hole (15) to form a grounding connection.
7. The split backpack variable frequency canned pump according to any one of claims 1 to 6, characterized in that The width of the control box (4) is greater than the width of the housing; the control box (4) forms an extension portion on the outside of the housing; a first cable outlet (9) is provided on the extension portion; the first cable outlet (9) avoids the housing and is used for the cable to enter the control box (4) to form an electrical connection and a signal connection with the control board (7).
8. The split backpack variable frequency canned pump according to any one of claims 1 to 6, characterized in that A base is provided at the bottom of the motor (2), and a pair of support structures (16) are provided on the base. The support structures (16) are supported on both sides of the bottom of the motor (2) and clamp both sides of the housing. Both sides of each support structure (16) are provided with oblique reinforcement ribs (17). The shape and size of the oblique reinforcement ribs (17) provided corresponding to the housing are adapted to the shape and size of the gap formed between the housing and the support structures (16).
9. The split backpack variable frequency canned pump according to claim 8 is characterized in that The upper end of the base has a certain width. A rib groove (18) is arranged at the upper end of the base. The rib groove (18) is arranged along the direction of the heat dissipation rib (19) on the housing. The heat dissipation rib (19) at the corresponding position is embedded in the rib groove (18).
10. The split backpack variable frequency canned pump according to claim 9 is characterized in that A rear support boss (20) and a front support boss (21) are arranged on the base, and the rear support boss (20) and the front support boss (21) are arranged in the middle of an area surrounded by a pair of support structures (16). At least two first waist-shaped connecting holes arranged at intervals are arranged on the rear support boss (20), and a second waist-shaped connecting hole is arranged on the front support boss (21). Corresponding to the positions of the first waist-shaped connecting hole and the second waist-shaped connecting hole, a corresponding connecting waist-shaped hole is arranged at the bottom of the casing, and a connecting piece passes through the first waist-shaped connecting hole and the second waist-shaped connecting hole from the bottom to the top from the bottom surface of the base to enter the lower part of the motor (2) for connection.