A Variable-Speed Fan Drive Protection Device and Method

Abstract

The present invention discloses a variable-speed fan drive protection device and method, which specifically relates to the technical field of drive equipment. The device includes a variable-speed motor, a motor mounting bracket, and a protective cover. An annular dust-holding cavity is provided inside the protective cover. A shielding disk is fixedly installed on the motor shaft in the area corresponding to the annular dust-holding cavity. A baffle is provided on one side of the shielding disk corresponding to the motor housing, and the baffle is fixedly connected to the protective cover. A dust-holding structure is provided on the inner wall of the annular dust-holding cavity, and a sticky structure is provided on the surface of the dust-holding structure. By setting the shielding disk to block dust particles, the entering dust particles first fall on the shielding disk, and with the rotation of the shielding disk, the dust particles are thrown onto the dust-holding structure on the inner surface of the annular dust-holding cavity, further effectively protecting the variable-speed motor body, thereby enhancing the safety and stability of the variable-speed motor when used in extreme environments.

Description

Technical Field

[0001] The present invention relates to the technical field of drive devices, and more specifically, to a variable-speed fan drive protection device and method. Background Art

[0002] A fan is a machine that relies on the input mechanical energy to increase the gas pressure and discharge the gas. It is a driven fluid machine. There are many types of fans, and their structural types are also different. However, regardless of the type of fan equipment, it mainly consists of an impeller and a drive device for driving the impeller to rotate. Among them, the drive device mainly uses an electric motor as the power source. A variable-speed fan uses a frequency converter or other speed control devices to precisely control the speed of the drive motor, thereby changing the speed of the impeller. Furthermore, by adjusting the power supply frequency or voltage, the speed of the motor is changed, and then the air volume and air pressure of the fan are adjusted. It is widely used in industrial, commercial, and civil buildings.

[0003] Since the variable-speed fan can adjust the air volume only by controlling the speed of the drive motor, there is no need to use a speed control device or other structures to connect the impeller and the output shaft of the drive motor, making the overall fan structure relatively compact and saving the space occupied by the equipment.

[0004] Among them, in order to effectively support and protect the drive motor, a support device is needed to firmly install the drive motor to ensure its stable operation. However, for some harsh usage environments (such as steel mills, coal-fired power plants, waste incineration plants, and the cooling and dust removal in mining, etc., which are high-temperature and high-dust particle usage environments), to ensure the stable operation of the drive motor and prevent external dust particles from entering the drive motor and affecting its normal use, a high-sealing and high-quality drive motor is required, and an effective protection structure for the drive motor is set up.

[0005] Among them, for a high-sealing drive motor, a corresponding sealing structure is set between the motor shaft and the motor housing, such as packing seals and labyrinth seals, etc. The sealing structure is arranged outside the bearing structure between the drive motor housing and the motor shaft to form corresponding protection for the bearings. When such a drive motor is in normal use, for example, when the motor rotates stably, the impeller has a balanced mass, and the fan is used in a relatively stable environment, the drive shaft of the drive motor can maintain stable coaxial rotation, and the motor shaft will not generate unbalanced pressure on the sealing structure and the bearing structure.

[0006] However, in some complex operating environments such as high temperature and high dust particles, especially after the use of the fan equipment trial parts, the impeller will be affected by many conditions, resulting in uneven texture and affecting the center of mass position (for example, after long-term use, dust particles and impeller blades form uncontrollable impacts resulting in uneven wear, dust particles adhere to the impeller in some high humidity environments, and errors in the production of the impeller itself). In this case, the rotation of the impeller will cause the motor shaft to deviate slightly from the axis due to the problem of center of mass offset (for example, under the action of centrifugal force, the motor shaft end tends to deviate in the direction of the centrifugal force).

[0007] Especially when the variable speed fan needs to run at high speed and constantly adjust the speed of the driving motor to adjust the speed of the impeller, the degree of offset deformation of the above-mentioned motor shaft will be relatively increased, and uncontrollable radial vibration will be formed. At this time, at the contact position between the motor shaft and the motor housing, due to the offset trend of the motor shaft, the fitting clearance between the motor shaft and the sealing structure will increase on one side and decrease on the other side. When the above-mentioned gap increases, dust particles can easily enter the area between the motor shaft and the sealing structure.

[0008] Although the sealing structure can temporarily block dust particles from entering the linear motor, the gap constantly changes due to the continuous rotation of the motor shaft, and the dust particles that enter between the motor shaft and the sealing structure will also continue to move. If the dust particles contain harder particles, such as metal microparticles, tiny sand particles, and mineral dust particles, friction damage will be caused between the motor shaft and the sealing structure, thereby affecting the matching stability between the motor shaft and the sealing structure and the sealing effect of the sealing structure. In severe cases, it may even cause structural damage to the drive motor, aggravate the vibration of the motor shaft, and affect the service life of the drive motor. Summary of the invention

[0009] The present invention provides a variable speed fan drive protection device and method, and aims to solve the problem that when the motor shaft of the variable speed fan produces offset vibration, the matching clearance between the motor shaft and the sealing structure will increase on one side, making it easy for dust particles to enter the area between the motor shaft and the sealing structure, affecting the matching stability between the motor shaft and the sealing structure, and affecting the sealing effect of the sealing structure.

[0010] To achieve the above-mentioned object, the present invention provides the following technical solutions: a variable speed fan drive protection device, comprising a variable speed motor, a motor mounting frame and a protective cover, the variable speed motor comprising a motor housing and a motor shaft, a shaft sealing assembly being arranged between the motor housing and the motor shaft, the motor housing and the protective cover being fixedly mounted on the motor mounting frame, the protective cover covering the outside of the output end of the motor shaft, and the protective cover corresponding to one side of the motor housing and the end of the motor housing being engaged with each other;

[0011] An annular dust-retaining cavity is arranged inside the protective cover. A shielding disc is fixedly installed on the motor shaft at the area corresponding to the annular dust-retaining cavity. A baffle is arranged on one side of the shielding disc corresponding to the motor housing. The baffle is fixedly connected to the protective cover. The edge of the shielding disc is located within the area covered by the annular dust-retaining cavity along the length direction of the motor shaft. A dust-retaining structure is arranged on the inner wall of the annular dust-retaining cavity, and a sticky structure is arranged on the surface of the dust-retaining structure.

[0012] In a preferred embodiment, an installation sleeve is arranged at the center of the shielding disc. The installation sleeve is fixedly sleeved on the motor shaft. The shielding disc is of a conical cover structure, and the edge of the shielding disc is arranged away from the motor housing.

[0013] In a preferred embodiment, an elastic ring piece is fixedly installed at the edge of the shielding disc. The elastic ring piece is of a thin sheet structure. The edge of the elastic ring piece bends towards the side away from the motor housing. A plurality of groups of counterweight bumps are arranged at the edge of the elastic ring piece on the side close to the motor housing. The plurality of groups of counterweight bumps are evenly distributed along the circumferential direction of the elastic ring piece.

[0014] In a preferred embodiment, the dust-retaining structure is a belt-type dust-retaining structure. The surface of the belt-type dust-retaining structure is coated with grease to form a sticky structure. The dust-retaining structure surrounds a circle in the annular dust-retaining cavity. Two extension channels are arranged in the protective cover. The two ends of the dust-retaining structure respectively extend out of the protective cover through the two extension channels. A slot structure that slidably engages with the edge of the dust-retaining structure is arranged on the inner side wall of the dust-retaining structure. The dust-retaining structure slides along the inner wall of the annular dust-retaining cavity.

[0015] In a preferred embodiment, two take-up drums are rotatably installed on the outer side of the annular dust-retaining cavity. The two ends of the dust-retaining structure are respectively connected to the two take-up drums and form a winding. A shielding cover is arranged on the outer side of the take-up drum, and a rotation driving structure is arranged on the take-up drum.

[0016] In a preferred embodiment, the extension channels are located above the protective cover. An oil storage cavity is arranged at the top of the extension channels. Grease is stored in the oil storage cavity. The dust-retaining structure passes through the grease in the oil storage cavity.

[0017] In a preferred embodiment, an auxiliary end cover is fixedly installed in the middle of the side of the protective cover away from the motor housing. The output end of the motor shaft penetrates through the protective cover and the auxiliary end cover. A reaction sleeve is fixedly installed in the area of the motor shaft inside the auxiliary end cover. A set of magnetic parts is arranged on the circumferential surface of the outer side of the reaction sleeve and on the circumferential surface of the inner side of the auxiliary end cover respectively. The magnetic poles of the corresponding sides of the two sets of magnetic parts are the same.

[0018] In a preferred embodiment, multiple groups of grooves are provided inside the auxiliary end cover. Buffer sliders are slidably installed in each groove. Each group of magnetic components in the auxiliary end cover is fixedly installed on the corresponding buffer slider. A buffer elastic member is provided between the buffer slider and the groove of the auxiliary end cover.

[0019] In a preferred embodiment, a sealing structure is provided between the protective cover and the motor housing. The sealing structure is a rubber pad structure and is adapted to the shape of the end of the variable-speed motor. A protective housing is fixedly installed on the motor mounting frame and covers the outside of the variable-speed motor. Vibration damping structures are provided between the variable-speed motor and the motor mounting frame and between the variable-speed motor and the protective housing.

[0020] A variable-speed fan drive protection method includes the following steps:

[0021] Step 1: Dust particles entering the interior of the protective cover through the gap between the auxiliary end cover and the motor shaft fall onto the shielding disc and are blocked by the shielding disc.

[0022] Step 2: The rotation of the shielding disc causes the dust particles to move around under the influence of centrifugal force and fall onto the dust-retaining structure in the annular dust-retaining cavity and are adhered by the viscous structure on the surface of the dust-retaining structure.

[0023] Step 3: Pull one end of the dust-retaining structure to make the dust-retaining structure slide along a circular trajectory in the annular dust-retaining cavity and enable a new dust-retaining structure to enter the annular dust-retaining cavity.

[0024] The beneficial effects of the present invention are as follows: By providing a shielding disc to block dust particles, the present invention enables the entering dust particles to first fall on the shielding disc. With the rotation of the shielding disc, the dust particles attached thereto are driven to generate a rotational movement. Then, under the action of centrifugal force, the dust particles are thrown onto the dust-retaining structure on the inner surface of the annular dust-retaining cavity and adhered thereto. Therefore, even if the center of mass of the impeller of the fan structure deviates due to various factors, resulting in vibration of the motor shaft deviating from the center of rotation direction during the high-speed operation of the fan, and uneven pressure at the shaft seal assembly of the motor shaft causes a gap, with the cooperation of the shielding disc and the annular dust-retaining cavity, dust particles are not easily introduced into the gap formed between the above-mentioned motor shaft and the corresponding structure of the motor housing, further effectively protecting the variable-speed motor body, thereby enhancing the safety and stability of the variable-speed motor when used in extreme environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0026] Figure 2 It is a schematic diagram of the cooperation between the variable-speed motor, the mounting frame and the protective cover of the present invention.

[0027] Figure 3 This is a diagram showing the mating state between the motor shaft of the present invention and the internal structure of the protective cover.

[0028] Figure 4 This is a schematic diagram showing the mating state between the shielding disc and the annular dust-retaining cavity of the present invention.

[0029] Figure 5 This is a perspective view of the shielding disc of the present invention.

[0030] Figure 6 This is a schematic diagram of the overall structure of the present invention using a belt-type dust-retaining structure.

[0031] Figure 7 This is a schematic diagram of the structure where the belt-type dust-retaining structure of the present invention leads out of the protective cover after surrounding the annular dust-retaining cavity for one circle.

[0032] Figure 8 For the present invention Figure 6 Enlarged view of the structure of part A.

[0033] Figure 9 This is a schematic diagram of the structure of the present invention after improving the auxiliary end cover.

[0034] Figure 10 This is a schematic diagram of the mating of the present invention applied to the fan structure.

[0035] Figure 11 This is a schematic diagram of the structure of the present invention with a protective housing added outside the variable-speed motor.

[0036] Figure 12 This is a schematic diagram of the structural design of the present invention for synchronously protecting the coupling when the transmission shaft structure has a coupling.

[0037] Figure 13 This is a flowchart of the protection method of the present invention.

[0038] Reference numerals: 1, variable-speed motor; 11, motor housing; 12, motor shaft; 13, shaft seal assembly; 2, motor mounting bracket; 21, protective housing; 22, damping structure; 3, protective cover; 31, annular dust-retaining cavity; 311, dust-retaining structure; 312, winding drum; 32, shielding disc; 321, elastic ring piece; 322, counterweight bump; 33, auxiliary end cover; 331, buffer slider; 332, buffer elastic member; 34, closing structure; 35, baffle; 36, reaction sleeve; 361, magnetic member; 37, extension channel; 371, oil storage cavity; 4, fan structure; 41, impeller shaft; 42, coupling. Detailed implementation manners

[0039] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0040] Refer to the instruction manual Figures 1 to 12 A variable speed fan drive protection device includes a variable speed motor 1, a motor mounting frame 2 and a protective cover 3, wherein the variable speed motor 1 includes a motor housing 11 and a motor shaft 12, a shaft sealing assembly 13 is arranged between the motor housing 11 and the motor shaft 12, and the output end of the motor shaft 12 (i.e., the end that needs to be connected to the impeller in the fan structure 4 for transmission) extends out of the motor housing 11. The above is the basic structure of the motor product, and this embodiment will not be explained in detail. The motor housing 11 and the protective cover 3 are both fixedly mounted on the motor mounting frame 2 (if there is a suitable structure on the motor mounting frame 2, the protective cover 3 can be directly installed, if there is no suitable structure, it can be indirectly installed through other connecting structures to ensure that the protective cover 3 and the motor housing 11 are fixed to each other), and the protective cover 3 covers the outside of the output end of the motor shaft 12, and the protective cover 3 is engaged with the end of the motor housing 11 on one side corresponding to the motor housing 11, and is provided with a closing structure 34, which is a rubber pad structure, and the closing structure 34 is adapted to the end shape of the variable speed motor 1, thereby forming a close contact, forming a seal between the protective cover 3 and the motor housing 11, and forming a buffer between the variable speed motor 1 and the protective cover 3 to avoid vibration between the two, and an auxiliary end cover 33 is fixedly installed in the middle of the side of the protective cover 3 away from the motor housing 11, and the output end of the motor shaft 12 passes through the protective cover 3 and the auxiliary end cover 33, so that the protective cover 3 can effectively cover and protect the shaft sealing assembly 13 between the output end of the motor shaft 12 and the motor housing 11.

[0041] Meanwhile, an annular dust-holding cavity 31 is arranged inside the protective cover 3. A shielding disc 32 is fixedly installed on the motor shaft 12 at the area corresponding to the annular dust-holding cavity 31. A baffle 35 is arranged on one side of the shielding disc 32 corresponding to the motor housing 11. The baffle 35 is fixedly connected to the protective cover 3, and the motor shaft 12 penetrates through the baffle 35, that is, the baffle 35 is located behind the shielding disc 32 and between the shielding disc 32 and the shaft seal assembly 13. The shielding disc 32 and the baffle 35 are close to each other with an assembly gap left to avoid friction between the shielding disc 32 and the baffle 35. Meanwhile, the edge of the shielding disc 32 is located within the area covered by the annular dust-holding cavity 31 along the length direction of the motor shaft 12. A dust-holding structure 311 is arranged on the inner wall of the annular dust-holding cavity 31. The dust-holding structure 311 is made of a material that can adsorb dust particles, such as a material with a microporous structure (the surface is covered with activated carbon), or a viscous structure with a viscous inner surface (such as a material like glue or grease is set on the surface). In addition, an assembly gap can be left between the motor shaft 12 and the baffle 35, and between the motor shaft 12 and the reaction sleeve 36. That is, the setting of the above structures will not increase the contact friction of the motor shaft 12.

[0042] By adopting the above scheme, during actual use, even if due to the harsh environment, some dust particles or other hard particles enter the inside of the protective cover 3 from behind the impeller of the fan structure 4 and the gap between the auxiliary end cover 33 and the motor shaft 12, the dust particles will be blocked by the shielding disc 32 and then fall on the shielding disc 32. The shielding disc 32 is installed on the motor shaft 12 and will rotate with the motor shaft 12 during actual use. Therefore, it can drive the dust particles attached to it to generate a rotational motion. Then, under the action of centrifugal force, the dust particles can be thrown onto the dust-holding structure 311 on the inner surface of the annular dust-holding cavity 31 and adhere to it. Since the shielding disc 32 is in a continuous rotating state during use, when the dust particles move to the edge of the shielding disc 32 and break away from the shielding disc 32, they will have a speed moving outward, and thus will not move towards the gap behind the shielding disc 32, further avoiding the movement of dust towards the fitting area between the motor shaft 12 and the end of the motor housing 11. Therefore, even if due to various factors, the center of mass of the impeller of the fan structure 4 is offset, resulting in vibration of the motor shaft 12 deviating from the center of rotation direction during high-speed operation of the fan, and the pressure is uneven at the shaft seal assembly 13 (or other structures such as the sealing cover) of the motor shaft 12, causing a gap, with the cooperation of the shielding disc 32 and the annular dust-holding cavity 31, the dust particles are not likely to enter the gap formed between the above-mentioned motor shaft 12 and the corresponding structure of the motor housing 11, further effectively protecting the variable-speed motor 1 body, thereby enhancing the safety and stability of the variable-speed motor 1 when used in an extreme environment.

[0043] Further, referring to the appended drawings of the specification Figures 3 to 5A mounting sleeve is provided at the center of the shielding disk 32, and the mounting sleeve is fixedly mounted on the motor shaft 12. The shielding disk 32 is a conical cover structure, and the edge of the shielding disk 32 is arranged away from the motor housing 11, so that a conical inner wall is formed on the side of the shielding disk 32 that receives the dust particles. During the rotation of the shielding disk 32, the dust particles are thrown out at the edge of the shielding disk 32 under the action of centrifugal force, and also have a movement away from the motor housing 11. Therefore, it can further prevent the dust particles from moving toward the matching position of the motor shaft 12 and the motor housing 11, thereby improving the protection effect.

[0044] It should be noted that, in the present embodiment, the shielding plate 32 can be made of a plastic structure, and the shielding plate 32 does not need to be transmitted, so the mounting sleeve at the center of the shielding plate 32 can be firmly installed with the motor shaft 12 by interference fit. If necessary, screws or keys can be added to strengthen the fixation. The shielding plate 32 itself is light in texture and will hardly affect the rotation of the motor shaft 12. At the same time, the solution provided in the present embodiment does not make close contact with the motor shaft 12, will not form resistance friction on the motor shaft 12, and will not form friction loss, which can greatly improve the service life of the device, and there is no need to improve the variable speed motor 1 itself. In actual production, according to the commonly used models of variable speed motors 1, corresponding protective covers 3 and motor shafts 12 can be set for adaptation. The structure used is also relatively small. Compared with improving the existing variable speed motor 1, the cost is low and the protection effect is better. Moreover, the present device is only arranged near the matching point between the motor shaft 12 and the motor housing 11, and does not need to occupy a large space. It can be adapted to a more compact use environment, such as the one attached to the instruction manual. Figure 10 When the device is applied to the fan structure 4, the protective cover 3 does not occupy a large space. In addition, in addition to being applicable to compact fan structures 4, this embodiment can also be simply modified for some motor shafts 12 that are long and the transmission components use a coupling 42, that is, the motor shaft 12 is connected to the impeller shaft 41 of the fan structure 4 through the coupling 42. The coupling 42 can be arranged behind the baffle 35. Figure 12 The coupling 42 can also be effectively protected by means of the cooperation of the shielding plate 32 and the annular dust chamber 31 (since a certain amount of activity needs to be retained in the two connecting structures of the coupling 42, a certain amount of clearance and movement will be retained. In a high temperature, high humidity or high dust environment, the coupling 42 may fail due to corrosion, wear or blockage. The direct drive design can avoid these problems. Setting the protective cover 3 on the outside of the coupling 42 can also provide joint protection for the coupling 42). It has strong applicability and high practicality.

[0045] Furthermore, in the above-described embodiments, although the fan structure 4 has been well protected during actual use and relatively few dust particles can enter the annular dust-holding cavity 31, after long-term use, the amount of dust particles remaining in the annular dust-holding cavity 31 will gradually increase. During actual use, the dust-holding structure 311 can be replaced during regular disassembly and maintenance of the equipment, or the amount of dust particles retained can be increased by increasing the space of the annular dust-holding cavity 31. However, for usage scenarios with space requirements, the above methods are not applicable. Therefore, the present embodiment also provides the following technical solution. Specifically, referring to the attached drawings of the specification Figures 6 to 8 , an elastic ring piece 321 is fixedly installed at the edge of the shielding disc 32. The elastic ring piece 321 has elasticity and is a thin sheet structure. The edge of the elastic ring piece 321 bends towards the side away from the motor housing 11. A plurality of counterweight bumps 322 are provided at the edge of the elastic ring piece 321 on the side close to the motor housing 11. The plurality of counterweight bumps 322 are evenly distributed along the circumferential direction of the elastic ring piece 321. When the elastic ring piece 321 rotates, affected by the centrifugal force, the edge of the elastic ring piece 321 and the counterweight bumps 322 tend to move radially away from the motor shaft 12. Therefore, the bending curvature of the edge of the elastic ring piece 321 will change. During actual use, the final separation point of the dust particles is at the edge of the elastic ring piece 321. Since the elastic ring piece 321 has elasticity, as the rotational speed of the variable-speed motor 1 is adjusted during use, the actual rotational speed of the elastic ring piece 321 also changes relatively, and the action of the centrifugal force received by the elastic ring piece 321 also changes, thereby causing the bending curvature of the elastic ring piece 321 to continuously change, and further changing the movement direction of the dust particles finally separated from the elastic ring piece 321, so that the dust particles can fall on a wider inner wall area of the dust-holding structure 311. Therefore, the amount of dust particles that can be retained also increases.

[0046] In addition, the present embodiment also provides the following scheme, which can timely process the dust retaining structure 311. Specifically, the dust retaining structure 311 is a belt-type dust retaining structure, that is, the dust retaining structure 311 is a belt structure. Specifically, the dust retaining structure 311 can use a tape structure, with a plastic sheet as the base, and adhesive is attached to the surface to form a sticky structure. It can also use a combination structure of an elastic sheet (plastic strip) and a cloth (pre-bonded), and a grease structure is applied to the cloth to form a sticky structure. The dust retaining structure 311 surrounds the annular dust retaining cavity 31, and the protective cover 3 is provided with two sets of extensions close to each other. Channel 37, both ends of the dust retaining structure 311 extend out of the protective cover 3 through two groups of extension channels 37 respectively, and a groove structure is provided on the inner wall of the annular dust retaining chamber 31, which is slidably engaged with the edge of the dust retaining structure 311, so that the dust retaining structure 311 can slide along the inner wall of the annular dust retaining chamber 31, and then during use, the dust retaining structure 311 can be pulled externally to make the dust retaining structure 311 move in the annular dust retaining chamber 31, and the part with dust particles adhered to it is gradually pulled out of the protective cover 3, and the new dust retaining structure 311 gradually enters the annular dust retaining chamber 31, thereby forming an effective replacement.

[0047] It should be noted that in order to improve the coverage rate of the dust retaining structure 311, the two groups of extension channels 37 need to be as close as possible. At the same time, a shielding structure can be set at the position of the extension channel 37 in the annular dust retaining cavity 31 to shield the two bending parts of the dust retaining structure 311. The shielding structure can be set to a triangular structure, so that the dust particles moving to the shielding structure can be guided to the dust retaining structure 311 on both sides. At the same time, the width of the extension channel 37 corresponding to the pulled-out part of the dust retaining structure 311 needs to be greater than the thickness of the dust retaining structure 311 to facilitate the removal of dust particles.

[0048] Furthermore, two groups of winding drums 312 are rotatably installed on the outer side of the annular dust retaining chamber 31, and the two ends of the dust retaining structure 311 are respectively connected to the two groups of winding drums 312 to form a winding. A shielding cover is provided on the outer side of the winding drum 312 to shield and protect the winding drum 312. A rotating driving structure, such as a knob, is provided on the winding drum 312, and the dust retaining structure 311 can be processed by manually rotating the winding drum 312, or a small motor structure can be set for automatic control, but the cost is relatively high.

[0049] At the same time, in order to ensure the stickiness of the dust retaining structure 311, refer to the attached manual. Figure 7, the extension channel 37 is located above the protective cover 3. An oil storage cavity 371 is provided at the top of the extension channel 37, and grease is stored in the oil storage cavity 371. The dust retention structure 311 passes through the grease in the oil storage cavity 371. Thus, when the new dust retention structure 311 enters the annular dust retention cavity 31, the grease can be replenished in time to ensure viscosity. At the same time, the extension channel 37 can also be blocked by means of the grease (since the dust retention structure 311 is operated regularly rather than all the time, the loss of the grease is relatively slow).

[0050] In the above embodiment, since a gap needs to be reserved between the auxiliary end cover 33 and the motor shaft 12, it is not appropriate to provide structures such as bearings (here, it directly corresponds to the external environment. Setting structures such as bearings will also directly contact dust particles, so it will also be affected, and it will increase the rotational wear of the motor shaft 12 and increase the transmission of the impeller vibration in the fan structure 4). To improve the support effect on the motor shaft 12, the present embodiment also provides the following technical solutions. Refer to the attached Figure 3 , a reaction sleeve 36 is fixedly installed in the area of the motor shaft 12 inside the auxiliary end cover 33. A set of magnetic members 361 are respectively provided on the circumferential surface of the outer side of the reaction sleeve 36 and the circumferential surface of the inner side of the auxiliary end cover 33. The magnetic poles on the mutually corresponding sides of the two sets of magnetic members 361 are the same. Thus, while ensuring no contact with the motor shaft 12, the motor shaft 12 can also be supported by magnetic force to reduce the swinging phenomenon of the motor shaft 12. At the same time, since the repulsive force between two opposite magnetic poles increases as they get closer, a certain buffering effect can also be formed on the motor shaft 12 to prevent the motor shaft 12 from directly driving the protective cover 3 to vibrate. On the contrary, under the repulsive force of the magnetic members 361, the vibration of the end of the motor shaft 12 deviating from the rotation center can also be reduced, forming a certain vibration damping effect.

[0051] Further, refer to the attached Figure 9 , multiple groups of grooves are provided inside the auxiliary end cover 33. A buffer slider 331 is slidably installed in each groove. Each group of magnetic members 361 in the auxiliary end cover 33 is fixedly installed on the corresponding buffer slider 331. A buffer elastic member 332 (such as a rubber pad or a spring structure) is provided between the buffer slider 331 and the groove of the auxiliary end cover 33, so as to increase the buffering effect on the motor shaft 12.

[0052] Further, refer to the attached Figure 11 , to improve the overall protection effect on the variable-speed motor 1, the present embodiment also provides the following technical solutions. Specifically, a protective housing 21 is fixedly installed on the motor mounting frame 2, and the protective housing 21 covers the outside of the variable-speed motor 1. Vibration damping structures 22 (such as buffer structures like rubber vibration damping pads) are provided between the variable-speed motor 1 and the motor mounting frame 2 and between the variable-speed motor 1 and the protective housing 21.

[0053] Referring to the attached drawings of the specification Figure 13 , the present invention also provides a variable-speed fan drive protection method, comprising the following steps:

[0054] Step 1: The dust particles that enter the inside of the protective cover 3 through the small gap between the auxiliary end cover 33 and the motor shaft 12 fall onto the shielding disc 32 and are blocked by the shielding disc 32;

[0055] Step 2: By the rotation of the shielding disc 32, the dust particles move around under the influence of centrifugal force and fall onto the dust-retaining structure 311 in the annular dust-retaining cavity 31 and are adhered by the viscous structure on the surface of the dust-retaining structure 311;

[0056] Step 3: Pull one end of the dust-retaining structure 311, so that the dust-retaining structure 311 slides along a circular trajectory in the annular dust-retaining cavity 31, and a new dust-retaining structure 311 is replaced in the annular dust-retaining cavity 31.

[0057] The above embodiments only represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation to 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 fan drive protection device, comprising a variable speed motor (1), a motor mounting frame (2) and a protection cover (3), wherein the variable speed motor (1) comprises a motor housing (11) and a motor shaft (12), a shaft sealing assembly (13) is provided between the motor housing (11) and the motor shaft (12), and the motor housing (11) and the protection cover (3) are both fixedly mounted on the motor mounting frame (2), characterized in that: The protective cover (3) covers the outside of the output end of the motor shaft (12), and a side of the protective cover (3) corresponding to the motor housing (11) is engaged with an end of the motor housing (11); An annular dust cavity (31) is provided inside the protective cover (3); a shielding plate (32) is fixedly mounted on a region of the motor shaft (12) corresponding to the annular dust cavity (31); a baffle (35) is provided on a side of the shielding plate (32) corresponding to the motor housing (11); the baffle (35) is fixedly connected to the protective cover (3); an edge of the shielding plate (32) is located within a region covered by the annular dust cavity (31) along a length direction of the motor shaft (12); a dust retaining structure (311) is provided on an inner wall of the annular dust cavity (31); a sticky structure is provided on the surface of the dust retaining structure (311); The dust retaining structure (311) is a belt-type dust retaining structure, the surface of which is coated with lubricating grease to form a viscous structure, the dust retaining structure (311) is arranged in a circle in the annular dust retaining cavity (31), and two groups of extension channels (37) are arranged in the protective cover (3), the two ends of the dust retaining structure (311) respectively extend out of the protective cover (3) through the two groups of extension channels (37), and a slot structure is arranged on the inner side wall of the dust retaining structure (311) to be slidably engaged with the edge of the dust retaining structure (311), and the dust retaining structure (311) slides along the inner wall of the annular dust retaining cavity (31); A closed structure (34) is provided between the protective cover (3) and the motor housing (11); the closed structure (34) is a rubber pad structure, and the closed structure (34) and the end shape of the variable speed motor (1) are mutually adapted; a protective housing (21) is fixedly mounted on the motor mounting frame (2); the protective housing (21) covers the outside of the variable speed motor (1); and a vibration reduction structure (22) is provided between the variable speed motor (1) and the motor mounting frame (2) and between the variable speed motor (1) and the protective housing (21).

2. A variable speed fan drive protection device according to claim 1, characterized in that: A mounting sleeve is provided at the centre of the shielding disc (32), the mounting sleeve being fixedly sleeved on the motor shaft (12); the shielding disc (32) is a conical cover structure, and the edge of the shielding disc (32) is arranged away from the motor housing (11).

3. A variable speed fan drive protection device according to claim 2, characterized in that: An elastic ring sheet (321) is fixedly mounted on the edge of the shielding plate (32); the elastic ring sheet (321) is a thin sheet structure; the edge of the elastic ring sheet (321) is bent towards a side away from the motor housing (11); a plurality of groups of counterweight convex points (322) are arranged at the edge of the elastic ring sheet (321) on a side close to the motor housing (11); the plurality of groups of counterweight convex points (322) are evenly distributed along the circumferential direction of the elastic ring sheet (321).

4. A variable speed fan drive protection device according to claim 3, characterized in that: Two groups of winding drums (312) are rotatably mounted on the outer side of the annular dust retaining chamber (31), the two ends of the dust retaining structure (311) are respectively connected to the two groups of winding drums (312) to form a winding, a shielding cover is arranged on the outer side of the winding drum (312), and a rotation driving structure is arranged on the winding drum (312).

5. A variable speed fan drive protection device according to claim 4, characterized in that: The extension channel (37) is located above the protective cover (3), and an oil storage chamber (371) is provided at the top of the extension channel (37). Lubricating grease is stored in the oil storage chamber (371), and the dust retaining structure (311) passes through the lubricating grease in the oil storage chamber (371).

6. A variable speed fan drive protection device according to claim 5, characterized in that: An auxiliary end cover (33) is fixedly mounted on the middle of a side of the protective cover (3) away from the motor housing (11); the output end of the motor shaft (12) passes through the protective cover (3) and the auxiliary end cover (33); a reaction sleeve (36) is fixedly mounted on the area of ​​the motor shaft (12) located inside the auxiliary end cover (33); a group of magnetic members (361) are respectively provided on the outer circumferential surface of the reaction sleeve (36) and the inner circumferential surface of the auxiliary end cover (33); and the magnetic poles of one side of the two groups of magnetic members (361) corresponding to each other are the same.

7. A variable speed fan drive protection device according to claim 6, characterized in that: The auxiliary end cover (33) is provided with a plurality of groups of grooves inside, each groove having a buffer slider (331) slidably mounted therein, each group of magnetic members (361) in the auxiliary end cover (33) being fixedly mounted on a corresponding buffer slider (331), and a buffer elastic member (332) being provided between the buffer slider (331) and the groove of the auxiliary end cover (33).

8. A protection method for a variable speed fan drive protection device as claimed in claim 7, characterized in that: The following steps are involved: Step 1: dust particles that enter the protective cover (3) through the gap between the auxiliary end cover (33) and the motor shaft (12) fall onto the shielding plate (32) and are blocked by the shielding plate (32); Step 2: The shielding disk (32) rotates to cause the dust particles to move around under the influence of centrifugal force and fall onto the dust retaining structure (311) in the annular dust retaining cavity (31), and are adhered to the sticky structure on the surface of the dust retaining structure (311); Step three: pull one end of the dust retaining structure (311) so that the dust retaining structure (311) slides along a circular trajectory in the annular dust retaining cavity (31), and a new dust retaining structure (311) is inserted into the annular dust retaining cavity (31).

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