A variable speed drive device for an air purifier fan with a housing

Abstract

The present invention discloses a variable-speed drive device for an air purifier fan with a housing, specifically relating to the technical field of air purifiers. It includes a variable-speed motor and a motor mounting assembly. The variable-speed motor includes a motor housing and a rotor shaft. The motor mounting assembly includes a fixed frame and an outer housing. A buffer assembly is provided between the outer housing and the motor housing. The rotor shaft includes an outer shaft and an inner shaft. The inner shaft is slidably mounted in the outer shaft, and inner-outer shaft buffer structures are provided between both ends of the outer shaft and the inner shaft. With the buffer between the outer shaft and the inner shaft by means of the inner-outer shaft buffer structure, while the inner shaft can have a slight relative movement with the outer shaft, the movement can also be buffered. The impact on the inner shaft is buffered and offset by the inner-outer shaft buffer structure, thereby ensuring that the outer shaft will not have axial movement due to the change in the force on the fan, further ensuring the relative stability of the motor housing in the outer housing and reducing noise.

Description

Technical Field

[0001] The present invention relates to the technical field of air purifiers, and more specifically, to a variable-speed drive device for an air purifier fan with an outer cover. Background Art

[0002] An air purifier, also known as an "air cleaner", air freshener, or purifier, refers to a household appliance that can adsorb, decompose, or convert various air pollutants (generally including PM2.5, dust, pollen, odors, decoration pollutants such as formaldehyde, bacteria, allergens, etc.), and effectively improve the air cleanliness. It is mainly divided into household, commercial, industrial, and building types.

[0003] The core of an air purifier is a fan structure composed of a motor and a fan. With the drive of the motor, an air flow passing through the inside of the purifier is formed. After passing through the processing equipment inside the purifier, the air is purified and then discharged again to continuously purify the air in the area.

[0004] Among them, in some large places, such as schools, hospitals, factory workshops, etc., a motor with a relatively large power is required as a drive device to meet the large air volume demand. However, due to the relatively large power of the motor used, the motor rotates relatively fast during use, and the vibration generated by the motor is also relatively large, and the generated noise is also relatively high. Therefore, for such air purifiers, the motor structure used needs to have a stable and powerful installation structure that can provide good buffering to ensure that the motor can operate stably in the purifier and reduce the operating noise.

[0005] For some special environments, for example, in some chemical workshops or offshore environments, there are some corrosive gases in the air, and the air is humid. If the motor is directly exposed for use, it is inevitable that corrosive gases and moisture in the air will fall near the motor, and in severe cases, even enter the inside of the motor, damaging structures such as the rotor coil inside the motor. Therefore, in order to provide good protection for the motor, in the prior art, a set of outer cover shells is provided inside the purifier to cover the outside of the motor. During installation, the motor is installed inside the outer cover shell to provide good protection for the motor. Multiple sets of buffer support structures can also be provided between the outer cover and the motor to effectively absorb and buffer the radial vibration formed when the motor rotates. At the same time, it can also alleviate the impact of the motor vibration on the purifier body, reduce vibration damage, and also reduce vibration noise.

[0006] However, in some factories or other usage locations, the purifier needs to be used for a long time. During the usage process, due to different usage requirements, the output speed of the motor is often adjusted to adjust the actual air volume. When the purifier is in use, the air flow is driven by the rotation of the fan. At this time, the radial vibration formed by the rotation of the fan can be fully absorbed by the vibration damping structure in the outer casing (since the motor requires extremely high rotational accuracy, there needs to be sufficient precise radial limitation between the motor shaft and the motor housing without any play). However, while the fan drives the air flow, the reaction force of the air will also cause an axial thrust on the motor shaft by the fan. In order to prevent the motor shaft from getting stuck due to thermal expansion and elongation and to adapt to the bearings and installation, there is usually a certain error in the circumferential direction of the motor shaft, so that the motor shaft can have a certain axial movement margin during actual operation. If the fan speed remains unchanged and the magnitude of the reaction force of the air remains the same, the motor shaft can be relatively stable. However, in the above-mentioned usage scenarios, the fan speed often changes, the force on the fan changes, which easily causes axial movement of the motor shaft, further strengthening the axial vibration of the motor. At this time, with the full support of the buffer structure in the outer casing, the axial vibration of the motor can be absorbed, but at the same time, it also allows the motor to have a small amount of axial movement in the outer casing (operation when compressing the vibration damping structure), thereby causing a change in the air pressure in the outer casing (the motor is similar to a piston structure), which easily sucks external air in from the installation gaps of the outer casing (such as the installation area between the outer casing and the motor shaft), reducing the protection effect on the motor. Summary of the Invention

[0007] A variable-speed drive device for a blower of an air purifier with an outer casing provided by the present invention aims to solve the following problem: When the existing air purifier needs to frequently adjust the fan speed, the reaction force of the air will also cause an axial thrust on the motor shaft by the fan, resulting in axial movement of the motor shaft, causing the motor to have a small amount of axial movement in the outer casing, which easily sucks external air in from the installation gaps of the outer casing, reducing the protection effect on the motor.

[0008] To achieve the above object, the present invention provides the following technical solution: A variable-speed drive device for a blower of an air purifier with an outer casing includes a variable-speed motor and a motor mounting assembly. The variable-speed motor includes a motor housing and a rotor shaft. The motor mounting assembly includes a fixing frame and an outer casing. The outer casing is fixedly installed on the fixing frame, and the variable-speed motor is fixedly installed in the outer casing. A buffer assembly is provided between the outer casing and the motor housing. The rotor shaft includes an outer shaft and an inner shaft, and the inner shaft is slidably installed in the outer shaft.

[0009] The upper and lower ends of the outer shaft both pass through the outer cover shell and rotate with the top and bottom ends of the outer cover shell. Inner and outer shaft buffer structures are arranged between the two ends of the outer shaft and the inner shaft. Convex step structures are arranged at the two ends of the outer shaft and at the positions of the inner shaft corresponding to the two ends of the outer shaft. The inner and outer shaft buffer structures are arranged between the two groups of convex step structures corresponding to the outer shaft and the inner shaft. The inner and outer shaft buffer structures are elastic structures. Shaft end sealing structures are arranged between the two ends of the outer shaft and the outer cover shell.

[0010] In a preferred embodiment, the top and bottom of the inner and outer shaft buffer structures are both fitted with the corresponding convex step structures to form a seal, and a storage groove is arranged on the inner side of the inner and outer shaft buffer structures in the area corresponding to the outer wall of the inner shaft, and lubricating oil is arranged in the storage groove and in the gap between the inner shaft and the outer shaft, and the cross-section of the storage groove is arranged to be a V-shaped cross-section.

[0011] In a preferred embodiment, the inner shaft is a hollow structure, an air flow channel is arranged in the middle of the inner shaft, the air flow channel runs downward through the inner shaft, an air outlet channel is arranged on the side wall at the top of the inner shaft, the air outlet channel is connected to the air flow channel, and an air flow acceleration structure is arranged inside the air flow channel.

[0012] In a preferred embodiment, the airflow acceleration structure is a plurality of fan blade structures, which are respectively fixedly mounted in a plurality of air outlet channels at the top of the inner shaft, and one end of the fan blade structure extends into the airflow channel.

[0013] In a preferred embodiment, the airflow acceleration structure is a spiral blade structure, which is fixedly installed in the airflow channel, and the inner shaft extends from the bottom end of the airflow channel and is provided with an expansion portion, and the spiral blade structure is a metal heat-conducting structure.

[0014] In a preferred embodiment, the shaft end sealing structure includes a movable end cover and a fixed end cover, the movable end cover is fixedly mounted on the outer shaft, the fixed end cover is fixedly mounted on the outer cover shell, the fixed end cover is rotationally fitted with the outer wall of the outer shaft, the movable end cover is rotationally engaged with the fixed end cover, an oil storage cavity is formed between the movable end cover and the fixed end cover in the area corresponding to the outer shaft, a reduced diameter section is provided in the area of ​​the outer shaft corresponding to the oil storage cavity, and the oil storage cavity is filled with sealing oil.

[0015] In a preferred embodiment, corresponding convex sleeves are arranged between the movable end cover and the fixed end cover, the two sets of convex sleeves are plugged into each other, and a sealing ring is arranged between the two sets of convex sleeves.

[0016] In a preferred embodiment, a surplus cavity is provided at the position of the moving end cover corresponding to the oil storage cavity, and a pressure equalizing membrane is fixedly installed in the surplus cavity. The pressure equalizing membrane is an elastic membrane structure, and a normal pressure air hole is provided on the side of the surplus cavity away from the pressure equalizing membrane, and the normal pressure air hole is connected to the outside air.

[0017] In a preferred embodiment, the buffer assembly includes an outer peripheral buffer pad and an axial buffer pad. The axial buffer pads are provided in two groups, and the two groups of axial buffer pads are respectively arranged at the top and bottom of the motor housing. The outer peripheral buffer pad surrounds the motor housing. A plurality of ventilation pipes are arranged inside the outer peripheral buffer pad. The ventilation pipes are hollow tube structures, and both ends of the ventilation pipes penetrate through the top and bottom of the outer housing respectively.

[0018] In a preferred embodiment, the variable-speed motor is installed inside the air purifier through a fixing frame. The fixing frame is fixedly connected to the volute. The fixing frame and the volute are jointly and fixedly installed in the air purifier. A plurality of reinforcing rib structures are arranged between the outer housing and the fixing frame. The outer housing is installed at the air inlet of the volute. An air flow guiding cylinder is also fixedly connected to the volute, and the air flow guiding cylinder extends to the air filtering and purifying assembly.

[0019] The beneficial effects of the present invention are as follows: By means of the buffer structure between the outer shaft and the inner shaft, the present invention buffers the buffer between the outer shaft and the inner shaft, enabling the inner shaft to have a slight relative movement with the outer shaft while also buffering this movement. Furthermore, during the use of the air purifier, even if the speed is frequently adjusted, resulting in a continuously changing axial impact on the inner shaft, the impact on the inner shaft can be buffered and offset by means of the buffer structure between the outer shaft and the inner shaft. Thus, it is ensured that the outer shaft will not have an axial movement due to the change in the force on the fan, further ensuring the relative stability of the motor housing in the outer housing. On the one hand, the vibration intensity of the variable-speed motor is reduced, and the noise is reduced. On the other hand, it can reduce the air pressure change caused by the slight movement of the motor housing in the outer housing, preventing external air from entering the outer housing and even entering the motor housing, thereby improving the protection effect on the variable-speed motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a perspective view of the variable-speed drive device of the present invention.

[0021] Figure 2 is an overall structural schematic diagram of the variable-speed drive device of the present invention.

[0022] Figure 3 is an installation schematic diagram of the variable-speed drive device of the present invention in the air purifier.

[0023] Figure 4 is an installation schematic diagram of the variable-speed motor of the present invention in the outer housing.

[0024] Figure 5 is a bottom view of the internal structure of the outer housing of the present invention.

[0025] Figure 6 is a structural schematic diagram of the sealing assembly of the present invention.

[0026] Figure 7 For the present invention Figure 6 is an enlarged view of the structure of part A.

[0027] Figure 8 This is a state diagram when the internal air pressure of the outer cover housing of the present invention changes, causing the pressure of the sealed oil body to change, so that the pressure equalizing film body deforms.

[0028] Figure 9 This is a schematic structural diagram of one of the air flow acceleration structures of the present invention.

[0029] Figure 10 Based on the present invention Figure 9 Top view of the distribution state of the air flow acceleration structure in the air outlet channel.

[0030] Figure 11 This is a schematic structural diagram of another air flow acceleration structure of the present invention.

[0031] Reference numerals are: 1, variable speed motor; 11, motor housing; 12, rotor shaft; 121, outer shaft; 122, inner shaft; 123, air flow channel; 124, air outlet channel; 125, convex step structure; 126, reduced diameter section; 127, fan blade structure; 128, spiral blade structure; 2, motor mounting assembly; 21, fixing frame; 22, outer cover housing; 221, adjusting air pipe; 23, volute; 24, air flow guiding cylinder; 3, buffer assembly; 31, outer peripheral buffer pad; 32, axial buffer pad; 4, inner and outer shaft buffer structure; 41, storage groove; 5, shaft end seal structure; 51, moving end cover; 52, fixed end cover; 53, oil storage cavity; 54, convex sleeve; 55, surplus cavity; 56, pressure equalizing film; 57, normal pressure air hole; 6, ventilation pipe; 7, air purifier; 71, air filtration and purification assembly. Detailed implementation manners

[0032] The following further describes the present application in detail with reference to the accompanying drawings. It is necessary to point out here that the following specific implementation manners are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above application content.

[0033] Refer to the accompanying specification Figures 1 to 11, A variable-speed drive device for an air purifier fan with a housing, comprising a variable-speed motor 1 and a motor mounting assembly 2. The variable-speed motor 1 includes a stator and a rotor. The stator includes a motor housing 11, and corresponding stator magnets are provided on the inner wall of the motor housing 11. The rotor includes a rotor shaft 12, and a rotor coil is provided on the rotor shaft 12. The motor mounting assembly 2 includes a fixing frame 21 and a housing shell 22. The housing shell 22 is fixedly installed on the fixing frame 21. The variable-speed motor 1 is fixedly installed in the housing shell 22. A buffer assembly 3 is provided between the housing shell 22 and the motor housing 11. The variable-speed motor 1 is installed inside the air purifier 7 through the fixing frame 21. Specifically, the fixing frame 21 is fixedly connected to the volute 23, and the fixing frame 21 and the volute 23 are jointly fixedly installed in the air purifier 7. Multiple groups of reinforcing rib structures are provided between the housing shell 22 and the fixing frame 21 to improve the stable support for the variable-speed motor 1, and the motor housing 11 is buffered in all directions by means of the buffer assembly 3 to reduce the influence of the vibration of the variable-speed motor 1 during operation on the air purifier 7 itself, improve the stability of the equipment operation, and reduce the operation noise. At the same time, the presence of the housing shell 22 can wrap and cover the variable-speed motor 1 in all directions. On the one hand, it reduces the possibility of contact between the residual corrosive gas in the external air and the moisture in the air and the variable-speed motor 1, and improves the protection effect on the variable-speed motor 1. On the other hand, the housing shell 22 can be made of sound-insulating material to further reduce the transmission of the internal noise of the variable-speed motor 1.

[0034] Among them, in order to reduce the axial impact and vibration effects on the rotor shaft 12 caused by the speed change of the fan structure in the air flow guiding cylinder 24 during the operation of the air purifier 7, the following technical solutions are provided in this embodiment. The rotor shaft 12 includes an outer shaft 121 and an inner shaft 122. The rotor coil is installed on the outer shaft 121, and the inner shaft 122 is slidably installed in the outer shaft 121. Among them, a sliding guiding structure, such as a sliding member, is provided between the inner shaft 122 and the outer shaft 121 to limit the axial movement between the outer shaft 121 and the inner shaft 122, so that only axial relative movement can be generated between the two. The upper and lower ends of the outer shaft 121 penetrate through the outer housing 22 and are rotatably matched with the top and bottom ends of the outer housing 22. Inner and outer shaft buffer structures 4 are provided between both ends of the outer shaft 121 and the inner shaft 122. Specifically, convex step structures 125 are provided at both ends of the outer shaft 121 and at positions of the inner shaft 122 corresponding to both ends of the outer shaft 121. The inner and outer shaft buffer structures 4 are provided between two groups of corresponding convex step structures 125 of the outer shaft 121 and the inner shaft 122. The inner and outer shaft buffer structures 4 are elastic structures (such as rubber). With the buffering of the inner and outer shaft buffer structures 4 between the outer shaft 121 and the inner shaft 122, while enabling the inner shaft 122 to generate a small amount of relative movement with the outer shaft 121, the movement can also be buffered. Furthermore, during the use of the air purifier 7, even if the speed is frequently adjusted, resulting in continuously changing axial impacts on the inner shaft 122, the impacts on the inner shaft 122 can be buffered and offset by means of the inner and outer shaft buffer structures 4. Furthermore, it is ensured that the outer shaft 121 will not generate axial movement due to the change in the force on the fan, further ensuring the relative stability of the motor housing 11 in the outer housing 22. On the one hand, the vibration intensity of the variable-speed motor 1 is reduced, and the noise is reduced. On the other hand, it is possible to reduce the air pressure change caused by the small movement of the motor housing 11 in the outer housing 22, so that external air enters the outer housing 22 or even enters the motor housing 11, improving the protection effect on the variable-speed motor 1.

[0035] It should be noted that in the traditional air purifier 7, its motor structure is mostly installed on the back side of the volute 23, that is, at one end away from the air inlet of the volute 23 (such as the Figure 3 shown top), and the motor itself deviates from the air flow path during the operation of the device. In order to improve the heat dissipation effect of the variable-speed motor 1, in this embodiment, the outer housing 22 is installed at the air inlet of the volute 23, that is, in the attached Figure 3At the bottom position of the volute 23 shown, the inner shaft 122 is fixedly connected to the fan in the volute 23. An air flow guiding cylinder 24 is also fixedly connected to the volute 23. The air flow guiding cylinder 24 extends to the air filtering and purifying component 71. The air processed by the air filtering and purifying component 71 is guided by the air flow guiding cylinder 24 (the air filtering and purifying component 71 is an important component of the air purifier 7, and its solutions are all prior arts, so no more details will be given in this embodiment). After flowing through the outer housing 22, the air enters the volute 23 and flows out from the air outlet of the volute 23 under the action of the fan. Multiple groups of heat dissipation fins are arranged outside the outer housing 22. Thus, in the case of long-term use of the device, the variable-speed motor 1 can be effectively cooled by the air flow formed by the air purifier 7 itself.

[0036] In the above embodiment, since heat is generated when the variable-speed motor 1 is running. Among them, in order to ensure the rotational concentricity of the rotor shaft 12, the radial matching precision of the outer shaft 121 and the inner shaft 122 (that is, the tightness of their circumferential sides) is relatively high. Although in actual use, the gap between the motor housing 11 and the outer housing 22 can be set relatively small to ensure the normal heat dissipation of the variable-speed motor 1, the above heat dissipation starts from the motor housing 11, and the heat dissipation of the center of the rotor shaft 12 is relatively slow. Therefore, if the device is in long-term use, excessive heat accumulation in the rotor shaft 12 itself leads to a relatively high temperature and different degrees of expansion, which easily causes the tightness between the inner shaft 122 and the outer shaft 121 to increase, and even directly causes jamming. The inner shaft 122 cannot generate relative axial movement with the outer shaft 121, and thus cannot directly buffer the axial impact. For this reason, this embodiment also provides the following technical solution. Specifically, refer to the attached Figure 4 The inner shaft 122 is of a hollow structure. An air flow channel 123 is arranged in the middle of the inner shaft 122. The air flow channel 123 runs through the inner shaft 122 downward. An air outlet channel 124 is arranged on the side wall at the top of the inner shaft 122. The air outlet channel 124 is communicated with the air flow channel 123. In actual use, since the rotor shaft 12 is vertically arranged in this embodiment, during the use of the device, when heat is generated by the rotor shaft 12 itself, the temperature of the air in the air flow channel 123 will rise, and the hot air will flow upward and be discharged from the air outlet channel 124, forming air convection. Thus, the rotor shaft 12 can be directly cooled, the heat dissipation effect of the variable-speed motor 1 can be improved, and it can be ensured that the inner shaft 122 will not be overheated and expanded to affect the matching effect with the outer shaft 121, and the operation stability of the device can be improved.

[0037] Furthermore, in order to improve the air flow effect inside the above-mentioned inner shaft 122, this embodiment also provides the following solution. Specifically, an air flow acceleration structure is arranged inside the air flow channel 123. Among them, refer to the attached Figure 9 and Figure 10, the air flow acceleration structure can be multiple groups of fan blade structures 127. The multiple groups of fan blade structures 127 are respectively fixedly installed in multiple air outlet channels 124 at the top of the inner shaft 122 to form an impeller structure, and one end of the fan blade structure 127 extends into the air flow channel 123. Thus, when the inner shaft 122 rotates, the air in the air flow channel 123 can be pushed by the fan blade structure 127, and with the centrifugal force at the air outlet channel 124 when the inner shaft 122 rotates at a high speed, the discharge of the air inside the air flow channel 123 can be accelerated, and the air flow effect inside the inner shaft 122 can be enhanced.

[0038] In addition, referring to the accompanying drawings of the specification Figure 11 , the air flow acceleration structure can also be a spiral blade structure 128. Specifically, the spiral blade structure 128 is fixedly installed in the air flow channel 123, and the bottom end of the air flow channel 123 extends out of the inner shaft 122 and is provided with an enlarged portion (the diameter of the spiral blade is larger than the diameter of the inner spiral blade in the air flow channel 123, forming a flat multi-layer structure). The spiral blade structure 128 is a metal structure. Thus, in actual use, the spiral blade structure 128 can also be like an auger structure to promote the air flow inside the air flow channel 123. At the same time, the spiral blade structure 128 itself can also be used as a heat dissipation structure to improve the heat dissipation effect on the inner shaft 122. In particular, the enlarged portion extending out of the air flow channel 123 can further improve the heat dissipation to the surrounding, ensuring the heat dissipation effect.

[0039] In addition, in order to ensure the coaxial fitting accuracy between the inner shaft 122 and the outer shaft 121, while ensuring the mutual sliding effect between the two and reducing the frictional loss therebetween, the present embodiment also provides the following technical solution. Specifically, referring to the accompanying drawings of the specification Figure 6, both the top and bottom of the inner and outer shaft buffer structure 4 are in contact with the corresponding convex step structure 125 and form a seal (a clamping structure or an adhesive structure can also be provided to ensure the stability and tightness of the installation between the inner and outer shaft buffer structure 4 and the convex step structure 125). A storage groove 41 is provided in the area of the inner side of the inner and outer shaft buffer structure 4 corresponding to the outer wall of the inner shaft 122. Lubricating oil is provided both in the storage groove 41 and in the fit tolerance gap between the inner shaft 122 and the outer shaft 121. Moreover, the cross-section of the storage groove 41 is set as a V-shaped cross-section. Specifically, due to the presence of lubricating oil between the inner shaft 122 and the outer shaft 121, vibration wear can be effectively reduced, and the frictional resistance between the two can also be reduced, effectively preventing the inner shaft 122 from driving the outer shaft 121 to move. At the same time, when relative movement occurs between the inner shaft 122 and the outer shaft 121, the corresponding inner and outer shaft buffer structure 4 will be compressed or stretched. For example, when the inner shaft 122 vibrates downward, the upper inner and outer shaft buffer structure 4 is compressed, and the lower inner and outer shaft buffer structure 4 is stretched (or pre-compressed and expands when the pressure decreases). The lubricating oil in the upper storage groove 41 has a downward extrusion effect, thereby ensuring that the overall lubricating oil does not flow out while also promoting the flow of lubricating oil in the fit tolerance gap between the inner shaft 122 and the outer shaft 121, further improving the lubrication effect.

[0040] In the above embodiment, due to the buffering of the inner and outer shaft buffer structure 4, the axial vibration of the motor housing 11 in the outer cover housing 22 can be effectively reduced, and thus the relative stability of the air pressure inside the outer cover housing 22 can be ensured as much as possible, and the air exchange between the inside and outside of the outer cover housing 22 caused by air flow due to air pressure change can be reduced. However, a fit clearance is formed between the outer shaft 121 and the outer cover housing 22 in rotational fit. When the temperature inside the outer cover housing 22 changes greatly, air expansion or contraction may also cause air exchange here. To solve this problem, the present embodiment also provides the following technical solutions. Specifically, refer to the accompanying drawings of the specification Figure 4 , Figure 6 and Figure 7A shaft end sealing structure 5 is provided between both ends of the outer shaft 121 and the outer cover shell 22. The shaft end sealing structure 5 includes a movable end cover 51 and a fixed end cover 52. The movable end cover 51 is fixedly mounted on the outer shaft 121 (and also forms a convex step structure 125 on the outer shaft 121). The fixed end cover 52 is fixedly mounted on the outer cover shell 22. The fixed end cover 52 is rotationally fitted with the outer wall of the outer shaft 121. The movable end cover 51 is rotationally engaged with the fixed end cover 52. An oil storage cavity is formed between the movable end cover 51 and the fixed end cover 52 at the area corresponding to the outer shaft 121. 53, a reduced diameter section 126 is provided in the area of ​​the outer shaft 121 corresponding to the oil storage chamber 53, and with the help of the gap between the reduced diameter section 126 and the fixed end cover 52, a gradually extending area is formed from the oil storage chamber 53 to the fixed end cover 52 and the outer shaft 121 fitting area, and the oil storage chamber 53 is filled with a sealing oil body lubricating oil or grease, which can form a certain lubrication while sealing, that is, with the help of the existence of the sealing oil body, the matching position of the outer shaft 121 and the outer cover shell 22 is sealed, thereby making it difficult for external air to enter the outer cover shell 22.

[0041] Furthermore, corresponding convex sleeves 54 are provided between the movable end cover 51 and the fixed end cover 52 , the two sets of convex sleeves 54 are plugged into each other, and a sealing ring is provided between the two sets of convex sleeves 54 , thereby ensuring that the sealed oil body in the oil storage cavity 53 area is not easy to leak.

[0042] For further information, please refer to the attached manual. Figure 7 and Figure 8 A residual chamber 55 is provided at the position of the movable end cover 51 corresponding to the oil storage chamber 53, and a pressure equalizing membrane 56 is fixedly installed in the residual chamber 55. The pressure equalizing membrane 56 is an elastic membrane structure. A normal pressure air hole 57 is provided on the side of the residual chamber 55 away from the pressure equalizing membrane 56, and the normal pressure air hole 57 is connected to the outside air.

[0043] It should be noted that, due to the presence of air inside the outer cover shell 22, under the action of the air pressure, the sealing oil in the residual chamber 55 is not easy to enter the outer cover shell 22 through the matching surface of the fixed end cover 52 and the outer shaft 121. At the same time, the air in the outer cover shell 22 is not easy to be discharged outward. When the air inside the outer cover shell 22 produces a pressure difference due to temperature changes, the pressure can act on the sealing oil in the oil storage chamber 53 through the matching gap between the fitting surfaces of the fixed end cover 52 and the outer shaft 121, and the sealing oil acts on the pressure equalizing membrane 56 with the pressure difference, causing it to bulge outward or inward, thereby adapting to the pressure difference in the outer cover shell 22. At the same time, it also ensures that the sealing oil will not be squeezed out from the gap between the convex sleeves 54 due to the increase in air pressure, thereby improving the sealing effect on the end of the inner shaft 122.

[0044] In addition, an adjustment air pipe 221 is provided on the outer cover housing 22. The adjustment air pipe 221 includes an intake pipe and an outlet pipe, and control valves are provided on both the intake pipe and the outlet pipe. Thus, during actual equipment assembly, safe air can be input into the outer cover housing 22 through the intake pipe and the outlet pipe, and when necessary, the internal air pressure of the outer cover housing 22 can be adjusted by adjusting the intake and outlet air volumes. However, this solution requires cooperation with an air pump structure and has a relatively high cost.

[0045] Furthermore, the buffer assembly 3 includes an outer peripheral buffer pad 31 and an axial buffer pad 32. The axial buffer pad 32 is provided in two groups, and the two groups of axial buffer pads 32 are respectively arranged at the top and bottom of the motor housing 11 to buffer the axial vibration of the variable-speed motor 1 itself. The outer peripheral buffer pad 31 is arranged around the motor housing 11 to provide effective positioning and radial buffering for the motor housing 11. Both the outer peripheral buffer pad 31 and the axial buffer pad 32 are preferably of a rubber pad structure. When necessary, an engaging structure can be provided between the outer peripheral buffer pad 31 and the motor housing 11 to ensure stable support for the motor housing 11.

[0046] In order to further improve the heat dissipation effect of the variable-speed motor 1, referring to the attached Figure 4 to the specification, a plurality of ventilation pipes 6 are arranged inside the outer peripheral buffer pad 31. The ventilation pipes 6 are of a hollow tube structure, and both ends of the ventilation pipes 6 respectively penetrate the top and bottom of the outer cover housing 22. Thus, during actual use, in cooperation with the designed position of the variable-speed motor 1, with the airflow formed by the air purifier 7, part of the airflow can pass through the ventilation pipes 6 to directly dissipate heat from the outer peripheral buffer pad 31, thereby improving the heat dissipation effect of the variable-speed motor 1. At the same time, the ventilation pipes 6 can also serve as a strengthening structure for the outer peripheral buffer pad 31 to improve the stability of the outer peripheral buffer pad 31. Moreover, the ventilation pipes 6 can directly dissipate heat from the outer peripheral buffer pad 31 effectively, preventing the outer peripheral buffer pad 31 from being overheated and expanding too much, which may increase the pressure on the motor housing 11 and affect the buffering effect.

[0047] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A variable speed drive device for an air purifier fan with an outer cover, comprising a variable speed motor (1) and a motor mounting assembly (2), wherein the variable speed motor (1) comprises a motor housing (11) and a rotor shaft (12), wherein the motor mounting assembly (2) comprises a fixing frame (21) and an outer cover shell (22), wherein the outer cover shell (22) is fixedly mounted on the fixing frame (21), wherein the variable speed motor (1) is fixedly mounted in the outer cover shell (22), and a buffer assembly (3) is provided between the outer cover shell (22) and the motor housing (11), wherein: The rotor shaft (12) comprises an outer shaft (121) and an inner shaft (122), wherein the inner shaft (122) is slidably mounted in the outer shaft (121); The upper and lower ends of the outer shaft (121) both pass through the outer housing shell (22) and are rotatably matched with the top and bottom ends of the outer housing shell (22); inner and outer shaft buffer structures (4) are provided between the two ends of the outer shaft (121) and the inner shaft (122); convex step structures (125) are provided at the two ends of the outer shaft (121) and at positions of the inner shaft (122) corresponding to the two ends of the outer shaft (121); the inner and outer shaft buffer structure (4) is provided between two groups of convex step structures (125) corresponding to the outer shaft (121) and the inner shaft (122); the inner and outer shaft buffer structure (4) is an elastic structure; and shaft end sealing structures (5) are provided between the two ends of the outer shaft (121) and the outer housing shell (22); The top and bottom of the inner and outer shaft buffer structure (4) are both in contact with the corresponding convex step structure (125) to form a seal, a storage groove (41) is provided in the area on the inner side of the inner and outer shaft buffer structure (4) corresponding to the outer wall of the inner shaft (122), lubricating oil is provided in the storage groove (41) and in the gap between the inner shaft (122) and the outer shaft (121), and the cross section of the storage groove (41) is set to be a V-shaped cross section; The shaft end sealing structure (5) comprises a movable end cover (51) and a fixed end cover (52), wherein the movable end cover (51) is fixedly mounted on the outer shaft (121), and the fixed end cover (52) is fixedly mounted on the outer housing shell (22), the fixed end cover (52) is rotationally fitted with the outer wall of the outer shaft (121), the movable end cover (51) and the fixed end cover (52) are rotationally engaged, an oil storage cavity (53) is formed at a region corresponding to the outer shaft (121) between the movable end cover (51) and the fixed end cover (52), a reduced diameter section (126) is provided at a region of the outer shaft (121) corresponding to the oil storage cavity (53), and the oil storage cavity (53) is filled with sealing oil; The buffer assembly (3) comprises a peripheral buffer pad (31) and an axial buffer pad (32), wherein the axial buffer pad (32) is provided in two groups, and the two groups of axial buffer pads (32) are respectively provided at the top and the bottom of the motor housing (11), and the peripheral buffer pad (31) is provided around the motor housing (11), and a plurality of groups of ventilation pipes (6) are provided inside the peripheral buffer pad (31), wherein the ventilation pipe (6) is a hollow pipe structure, and the two ends of the ventilation pipe (6) respectively penetrate the top and the bottom of the outer cover shell (22).

2. The variable speed drive device for a fan of an air purifier with an outer cover according to claim 1, characterized in that: The inner shaft (122) is a hollow structure, an airflow channel (123) is provided in the middle of the inner shaft (122), the airflow channel (123) penetrates downwardly through the inner shaft (122), an air outlet channel (124) is provided on the side wall at the top of the inner shaft (122), the air outlet channel (124) is communicated with the airflow channel (123), and an airflow acceleration structure is provided inside the airflow channel (123).

3. The variable speed drive device for a fan of an air purifier with an outer cover according to claim 2, characterized in that: The airflow acceleration structure is a plurality of groups of fan blade structures (127), and the plurality of groups of fan blade structures (127) are respectively fixedly mounted in a plurality of air outlet channels (124) at the top of the inner shaft (122), and one end of the fan blade structure (127) extends into the airflow channel (123).

4. The variable speed drive device for a fan of an air purifier with an outer cover according to claim 2, characterized in that: The airflow acceleration structure is a spiral blade structure (128), the spiral blade structure (128) is fixedly installed in the airflow channel (123), and the inner shaft (122) extends from the bottom end of the airflow channel (123) and is provided with an expansion portion, and the spiral blade structure (128) is a metal heat-conducting structure.

5. A variable speed drive device for a fan of an air purifier with an outer cover according to claim 3 or 4, characterized in that: Mutually corresponding convex sleeves (54) are provided between the movable end cover (51) and the fixed end cover (52); two groups of the convex sleeves (54) are plugged into each other, and a sealing ring is provided between the two groups of the convex sleeves (54).

6. The variable speed drive device for a fan of an air purifier with an outer cover according to claim 5, characterized in that: A surplus cavity (55) is arranged at a position of the movable end cover (51) corresponding to the oil storage cavity (53), a pressure equalizing membrane (56) is fixedly installed in the surplus cavity (55), the pressure equalizing membrane (56) is an elastic membrane structure, and a normal pressure pore (57) is arranged on a side of the surplus cavity (55) away from the pressure equalizing membrane (56), and the normal pressure pore (57) is connected to the outside air.

7. A variable speed drive device for a fan of an air purifier with an outer cover according to claim 6, characterized in that: The variable speed motor (1) is installed inside the air purifier (7) via a fixing frame (21); the fixing frame (21) is fixedly connected to the volute (23); the fixing frame (21) and the volute (23) are fixedly installed together in the air purifier (7); a plurality of groups of reinforcing rib structures are arranged between the outer cover shell (22) and the fixing frame (21); the outer cover shell (22) is installed at the air inlet of the volute (23); an airflow guide cylinder (24) is also fixedly connected to the volute (23); the airflow guide cylinder (24) extends to the air filter purification component (71).

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