Blower with adjustable blade tip clearance

Abstract

The present invention relates to the field of blowers, and in particular to a blower with adjustable blade tip clearance. The blower includes a casing, a motor shaft, a bearing device, an impeller, a volute, and a plurality of adjustment springs; the inner side of the impeller is fixed to one end of the motor shaft, and a first adjustment magnet is fixedly provided on the outer side of the impeller; the volute includes a blast channel, an air inlet guide vane, a matching hole, and an adjustment pressure plate; the air inlet guide vane is fixedly provided in the blast channel, and the air inlet guide vane is fixedly provided with a second adjustment magnet; the positions of the first adjustment magnet and the second adjustment magnet correspond, and the magnetic poles of the corresponding surfaces of the two are the same; the volute is slidably fitted with the outer wall of the casing through the matching hole; the adjustment spring is in a compressed state, and the thrust generated by the adjustment spring on the volute is equal in magnitude and opposite in direction to the repulsive force generated between the first adjustment magnet and the second adjustment magnet. The blower ensures that the blade tip clearance between the impeller and the volute remains unchanged, thereby improving the blowing quality of the magnetic levitation blower.

Description

Technical Field

[0001] The present invention relates to the field of blowers, and in particular to a blower with adjustable blade tip clearance. Background Art

[0002] The tip clearance of the blower has always been an important factor affecting the efficiency and safety of the blower. Figure 2 、 Figure 3 As shown in the figure, the allowable design range of the designed blade tip clearance is S0. When the stator and rotor of the motor produce relative displacement due to temperature increase and deformation, the actual blade tip clearance can be S1; if the elongation of the rotor is greater than the elongation of the stator, the actual blade tip clearance S1 between the impeller and the volute is smaller than the allowable design range S0, and there is a risk of mutual scraping between the impeller and the volute, which will pose a safety hazard; if the elongation of the rotor is less than the elongation of the stator, the actual blade tip clearance S1 between the impeller and the volute is larger than the allowable design range S0, then the flow field efficiency is reduced, resulting in reduced blower efficiency.

[0003] A Chinese utility model patent application (publication number CN205478443U, publication date: August 17, 2016) discloses a magnetic levitation high-speed centrifugal blower comprising a magnetic levitation motor, a connecting plate, a volute, a current collector, an impeller, a diffuser, and a sealing disk. The magnetic levitation motor is connected to the volute via the connecting plate, and its motor shaft is connected to the impeller via a locking rod equipped with a locking nut. A sealing disk and a diffuser are mounted on the connecting plate, and the current collector is connected to the volute. This magnetic levitation high-speed centrifugal blower utilizes a spigot-type connection between the magnetic levitation motor and the volute via the connecting plate. The diffuser and sealing disk are mounted on the connecting plate, reducing the number of parts and improving assembly accuracy, coaxiality, and structural rigidity. The sealing disk and motor shaft have a clearance fit, which is appropriately designed to prevent friction between the motor shaft and the sealing disk while ensuring good airtightness. A metal filter screen is added to the current collector inlet, improving the safety of the blower operation. The blower has the advantages of simple structure and safe operation.

[0004] The existing technology has the following deficiencies: the volute of the traditional magnetic levitation blower is directly fixed on the casing, and the casing cannot adjust the position of the volute, that is, the blade tip clearance between the impeller and the volute cannot be adjusted; when the motor stator or motor rotor and other parts cause relative displacement between the impeller and the volute due to temperature changes, the blade tip clearance between the impeller and the volute will not meet the requirements; as a result, the impeller and the volute will scrape against each other due to a small gap, or the flow field efficiency will be reduced due to a large gap, which will lead to a reduction in the efficiency of the blower, thereby reducing the blowing quality of the magnetic levitation blower. Summary of the Invention

[0005] The purpose of the present invention is: to address the above-mentioned problems, it is proposed to set a matching hole so that the volute and the casing can slide together in the axial direction, set a first adjusting magnetic steel and a second adjusting magnetic steel respectively to generate a repulsive force, and set an adjusting spring to generate a thrust equal to the repulsive force and opposite in direction; through the dynamic adjustment of the repulsive force and the thrust in the axial direction, the relative position of the volute and the impeller in the axial direction is ensured to remain unchanged; thereby ensuring that the blade tip clearance between the impeller and the volute remains unchanged, thereby improving the blowing quality of the magnetic levitation blower to form a blower with adjustable blade tip clearance.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0007] A blower with adjustable blade tip clearance, which includes a casing, a motor shaft, a bearing device, an impeller, a volute and multiple adjusting springs; the motor stator is fixedly embedded in the inner hole of the casing, and the motor shaft is fixedly provided with a motor rotor corresponding to the position of the motor stator; the inner side of the impeller is fixed to one end of the motor shaft, and the outer side of the impeller is fixedly provided with a first adjusting magnet; the volute includes a blast channel, an air inlet guide vane, a matching hole and an adjusting pressure plate, the air inlet guide vane is fixedly provided in the blast channel, and the air inlet guide vane is fixedly provided with a second adjusting magnet; the positions of the first adjusting magnet and the second adjusting magnet correspond, and the magnetic poles of the corresponding surfaces of the two are the same; the volute slides with the outer wall of the casing through the matching hole, and a plurality of first spring holes and a plurality of second spring holes are respectively provided on the inner side of the casing and the outer side of the adjusting pressure plate, and the two ends of the adjusting spring are respectively in contact with the bottom surfaces of the first spring hole and the second spring hole; the adjusting spring is in a compressed state, and the thrust generated by the adjusting spring on the volute is equal in magnitude and opposite in direction to the repulsive force generated between the first adjusting magnet and the second adjusting magnet.

[0008] Preferably, the impeller is provided with an axially penetrating screw hole, one end of the motor shaft is provided with an axial threaded hole, and the blower is also provided with a locking screw; the locking screw passes through the screw hole and is screwed into the threaded hole to lock the impeller to one end of the motor shaft; the head of the locking screw is provided with a first magnetic steel hole, and the first adjusting magnet is fixedly embedded in the first magnetic steel hole.

[0009] Preferably, the air inlet guide vane is provided with a fairing, which is used to guide the air at the air inlet end of the blast channel; the fairing is provided with a second magnetic steel hole, and the second adjustment magnetic steel is fixedly embedded in the second magnetic steel hole.

[0010] Preferably, there is a clearance fit between the fitting hole and the outer wall of the casing.

[0011] Preferably, an O-ring is provided between the fitting hole and the outer wall of the casing.

[0012] Preferably, the plurality of first spring holes and the plurality of second spring holes are distributed along the circumferential direction.

[0013] Preferably, the bearing device is a plurality of angular contact ball bearings, and the plurality of angular contact ball bearings are respectively arranged at both ends of the motor shaft.

[0014] Preferably, the angular contact ball bearings at both ends of the motor shaft are installed face to face.

[0015] Preferably, a wave spring is provided between the angular contact ball bearing at the other end of the motor shaft and the housing, and the wave spring is used to provide a pre-tightening force to the angular contact ball bearing to prevent the axial movement thereof.

[0016] Preferably, the outer wall fixing sleeve of the motor rotor is provided with a magnetic steel protective sleeve, which is used to protect the motor rotor and prevent it from being damaged due to collision or the like.

[0017] The advantages of the blower with adjustable blade tip clearance using the above technical solution of the present invention are:

[0018] By varying the length of the adjustment spring, the preload of the adjustment spring is balanced with the repulsive force generated between the first and second adjustment magnets. When the blower's temperature rises after operation, and the motor shaft extends to the right more than the volute extends to the right, the distance between the first and second adjustment magnets decreases, resulting in a repulsive force greater than the preload of the adjustment spring. The volute then moves to the right, compressing the adjustment spring and increasing its preload. The repulsive force between the first and second adjustment magnets decreases due to the increased distance between them. The two forces are balanced again, ensuring blade tip clearance. When the motor shaft extends to the right less than the volute extends to the right, the adjustment spring is compressed, and the thrust generated by the adjustment spring exceeds the repulsive force between the first and second adjustment magnets. The volute then moves to the left, stretching the adjustment spring and decreasing its preload. The repulsive force between the first and second adjustment magnets increases due to the decreased distance between them. The two forces are balanced again, ensuring blade tip clearance and improving the airflow quality of the magnetic levitation blower. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 Schematic diagram of the structure of allowable blade tip clearance.

[0021] Figure 3 This is a structural diagram of the actual blade tip clearance.

[0022] Figure 4 、 Figure 5 Schematic diagram of the locking screw structure.

[0023] Figure 6 、 Figure 7 Schematic diagram of the structure of the adjusting pressure plate.

[0024] Figure 8 Schematic diagram of the volute structure.

[0025] Figure 9 、 Figure 10 A schematic diagram of the casing structure.

[0026] Figure 11 This is a schematic diagram of the motor shaft structure.

[0027] 59-O-ring, S0-allowable design range of blade tip clearance, S1-actual blade tip clearance. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] Example 1

[0030] like Figure 1The blower shown in the figure has an adjustable blade tip clearance, which includes a casing 1, a motor shaft 2, a bearing device 3, an impeller 4, a volute 5 and a plurality of adjustment springs 6; a motor stator 11 is fixedly embedded in the inner hole of the casing 1, and a motor rotor 12 corresponding to the position of the motor stator 11 is fixedly provided on the motor shaft 2; the inner side of the impeller 4 is fixed to one end of the motor shaft 2, and a first adjustment magnet 41 is fixedly provided on the outer side of the impeller 4; the volute 5 includes a blast channel 51, an air inlet guide vane 52, a matching hole 53 and an adjustment pressure plate 54, the air inlet guide vane 52 is fixedly provided in the blast channel 51, and the air inlet guide vane 52 is fixedly provided with a second Adjusting magnet 55; the first adjusting magnet 41 and the second adjusting magnet 55 are positioned correspondingly, and the magnetic poles of their corresponding surfaces are the same; the volute 5 slides with the outer wall of the housing 1 through the mating hole 53, and a plurality of first spring holes 13 and a plurality of second spring holes 56 are respectively provided on the inner side of the housing 1 and the outer side of the adjusting pressure plate 54. The ends of the adjusting spring 6 contact the bottom surfaces of the first spring holes 13 and the second spring holes 56, respectively; the adjusting spring 6 is in a compressed state, and the thrust generated by the adjusting spring 6 on the volute 5 is equal in magnitude and opposite in direction to the repulsive force generated between the first adjusting magnet 41 and the second adjusting magnet 55. In this method, the preload force of the adjusting spring 6 is balanced with the repulsive force generated between the first adjusting magnet 41 and the second adjusting magnet 55 by changing the length of the adjusting spring 6. When the temperature of the blower rises after operation, when the extension of the motor shaft 2 to the right is greater than the extension of the volute 5 to the right, that is, the distance between the first regulating magnet 41 and the second regulating magnet 55 is close, the repulsive force generated by the two is greater than the preload force of the regulating spring 6; then the volute 5 moves to the right, at this time the regulating spring 6 is compressed, the preload force of the regulating spring 6 becomes larger, and the repulsive force between the first regulating magnet 41 and the second regulating magnet 55 decreases due to the increase in distance; the two forces are balanced again, thereby ensuring the blade tip clearance. When the rightward extension of the motor shaft 2 is less than the rightward extension of the volute 5, that is, the adjusting spring 6 is compressed, the thrust generated by the adjusting spring 6 is greater than the repulsive force generated between the first adjusting magnet 41 and the second adjusting magnet 55; then the volute 5 moves to the left, at this time the adjusting spring 6 is stretched, the pre-tightening force of the adjusting spring 6 becomes smaller, and the repulsive force between the first adjusting magnet 41 and the second adjusting magnet 55 increases due to the smaller distance; the two forces are balanced again, thereby ensuring the blade tip clearance and improving the blowing quality of the magnetic levitation blower.

[0031] like Figure 1 、 Figure 4 、 Figure 5 As shown, the impeller 4 is provided with an axially penetrating screw hole 42, one end of the motor shaft 2 is provided with an axial threaded hole 21, and the blower is also provided with a locking screw 7; the locking screw 7 passes through the screw hole 42 and is screwed into the threaded hole 21 to lock the impeller 4 to one end of the motor shaft 2; the head of the locking screw 7 is provided with a first magnetic steel hole 71, and the first adjusting magnetic steel 41 is fixedly embedded in the first magnetic steel hole 71.

[0032] The air inlet guide vane 52 is provided with a fairing 57, which is used to guide the air at the air inlet end of the blast channel 51; the fairing 57 is provided with a second magnetic steel hole 58, and the second adjustment magnetic steel 55 is fixedly embedded in the second magnetic steel hole 58.

[0033] There is a clearance fit between the fitting hole 53 and the outer wall of the housing 1 so that the fitting hole 53 can be quickly inserted into the outer wall of the housing 1 .

[0034] An O-ring is provided between the fitting hole 53 and the outer wall of the housing 1. The O-ring provides radial preload and sealing effect.

[0035] The plurality of first spring holes 13 and the plurality of second spring holes 56 are distributed along the circumferential direction. The bearing device 3 is a plurality of angular contact ball bearings, and the plurality of angular contact ball bearings are respectively arranged at both ends of the motor shaft 2. The angular contact ball bearings at both ends of the motor shaft 2 are installed face to face.

[0036] A wave spring 8 is provided between the angular contact ball bearing at the other end of the motor shaft 2 and the housing 1 . The wave spring 8 is used to provide a preload force to the angular contact ball bearing to prevent axial movement thereof.

[0037] The outer wall of the motor rotor 12 is fixed with a magnetic steel protective sleeve 9, which is used to protect the motor rotor 12 and prevent it from being damaged due to collision or other reasons.

Claims

1. A blower with adjustable blade tip clearance, characterized in that: The blower comprises a casing (1), a motor shaft (2), a bearing device (3), an impeller (4), a volute (5) and a plurality of adjustment springs (6); a motor stator (11) is fixedly embedded in the inner hole of the casing (1), and a motor rotor (12) corresponding to the position of the motor stator (11) is fixedly provided on the motor shaft (2); the inner side of the impeller (4) is fixed to one end of the motor shaft (2), and the outer side of the impeller (4) is fixedly provided with a first adjustment magnetic steel (41); the volute (5) comprises an air blast channel (51), an air inlet guide vane (52), a matching hole (53) and an adjustment pressure plate (54); the air inlet guide vane (52) is fixedly provided in the air blast channel (51), and the air inlet guide vane (52) is fixedly provided with a second adjustment magnetic steel (41). Steel (55); the positions of the first regulating magnetic steel (41) and the second regulating magnetic steel (55) correspond to each other, and the magnetic poles of the corresponding surfaces of the two are the same; the volute (5) is slidably matched with the outer wall of the housing (1) through the matching hole (53), and a plurality of first spring holes (13) and a plurality of second spring holes (56) are respectively provided on the inner side of the housing (1) and the outer side of the regulating pressure plate (54), and the two ends of the regulating spring (6) are respectively in contact with the bottom surfaces of the first spring holes (13) and the second spring holes (56); the regulating spring (6) is in a compressed state, and the thrust generated by the regulating spring (6) on the volute (5) is equal in magnitude and opposite in direction to the repulsive force generated between the first regulating magnetic steel (41) and the second regulating magnetic steel (55).

2. A blower with adjustable blade tip clearance according to claim 1, characterized in that: The impeller (4) is provided with an axially penetrating screw hole (42), one end of the motor shaft (2) is provided with an axially threaded hole (21), and the blower is further provided with a locking screw (7); the locking screw (7) passes through the screw hole (42) and is screwed together with the threaded hole (21) to lock the impeller (4) to one end of the motor shaft (2); the head of the locking screw (7) is provided with a first magnetic steel hole (71), and the first adjustment magnetic steel (41) is fixedly embedded in the first magnetic steel hole (71).

3. The blower with adjustable blade tip clearance according to claim 1, characterized in that: The air inlet guide vane (52) is provided with a fairing (57), and the fairing (57) is used to guide the air at the air inlet end of the blast channel (51); the fairing (57) is provided with a second magnetic steel hole (58), and the second adjustment magnetic steel (55) is fixedly embedded in the second magnetic steel hole (58).

4. The blower with adjustable blade tip clearance according to claim 1, characterized in that: There is a clearance fit between the matching hole (53) and the outer wall of the casing (1).

5. The blower with adjustable blade tip clearance according to claim 1, characterized in that: An O-type sealing ring is provided between the matching hole (53) and the outer wall of the housing (1).

6. The blower with adjustable blade tip clearance according to claim 1, characterized in that: The plurality of first spring holes (13) and the plurality of second spring holes (56) are distributed along the circumferential direction.

7. The blower with adjustable blade tip clearance according to claim 1, characterized in that: The bearing device (3) is a plurality of angular contact ball bearings, and the plurality of angular contact ball bearings are respectively arranged at both ends of the motor shaft (2).

8. The blower with adjustable blade tip clearance according to claim 7, characterized in that: The angular contact ball bearings at both ends of the motor shaft (2) are mounted face to face.

9. The blower with adjustable blade tip clearance according to claim 7, characterized in that: A wave spring (8) is provided between the angular contact ball bearing at the other end of the motor shaft (2) and the housing (1), and the wave spring (8) is used to provide a preload force to the angular contact ball bearing to prevent axial movement thereof.

10. The blower with adjustable blade tip clearance according to claim 1, characterized in that: The outer wall fixing sleeve of the motor rotor (12) is provided with a magnetic steel protective sleeve (9), and the magnetic steel protective sleeve (9) is used to protect the motor rotor (12) and prevent it from being damaged due to collision or other reasons.

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