A volute fan for a sweeper

Abstract

A volute fan for sweeper, including volute, impeller, rotor assembly, stator assembly, circuit board, the impeller is arranged in the inner chamber of volute, the stator assembly and circuit board are connected on volute, the iron core winding of stator assembly is connected with circuit board through wire, the rotor assembly includes rotating shaft, magnetic ring, magnetic sleeve, limiting piece, the rotating shaft is arranged on the bearing body of stator assembly, the limiting piece connects rotating shaft and bearing piece, one end of rotating shaft passes through volute and is connected with impeller, the other end of rotating shaft is connected with magnetic sleeve, the magnetic ring is fixed in magnetic sleeve, the magnetic sleeve is sleeved on stator assembly, the magnetic ring corresponds with the iron core winding of stator assembly, the number of the blade of impeller is greater than 9. The volute fan for sweeper has the advantages that the vacuum degree of turbine fan can be improved to 30-35Kpa, which is higher than the vacuum degree of fan in the prior art.

Description

Technical Field

[0001] This utility model relates to the field of sweeper fan technology, and more particularly to a volute fan used in sweepers. Background Technology

[0002] The current maximum vacuum level of sweeper fans ranges from 4 to 20 kPa. With increasing customer demand for cleaning stubborn stains, the current suction power is insufficient. Furthermore, high-speed rotation can lead to issues such as the shaft becoming loose and bearings rotating with it, resulting in motor instability and excessive noise. As the vacuum level increases, the centrifugal force during motor rotation can cause the magnetic ring to break or explode, severely affecting product stability and posing safety hazards. Therefore, the structure of sweeper fans requires further improvement. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a volute fan for sweeping machines with strong suction and a fan vacuum degree of more than 30Kpa, in view of the above-mentioned existing technology.

[0004] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: This volute fan for a sweeping machine includes a volute, an impeller, a rotor assembly, a stator assembly, and a circuit board. The impeller is disposed in the inner cavity of the volute. The stator assembly and the circuit board are connected to the volute. The iron core winding of the stator assembly is connected to the circuit board through a wire. The rotor assembly includes a rotating shaft, a magnetic ring, a magnetic sleeve, and a limiting member. The rotating shaft passes through the bearing body of the stator assembly. The limiting member connects the rotating shaft and the bearing body. One end of the rotating shaft passes through the volute and is connected to the impeller. The other end of the rotating shaft is connected to the magnetic sleeve. The magnetic ring is fixed inside the magnetic sleeve. The magnetic sleeve is sleeved on the stator assembly. The magnetic ring corresponds to the iron core winding of the stator assembly. The impeller has more than 9 blades.

[0005] As an improvement, the magnetic sleeve can preferably be connected to the magnetic ring with an interference fit, and the inner diameter of the magnetic sleeve is 0.05 to 0.1 mm smaller than the outer diameter of the magnetic ring. This allows the magnetic ring to withstand a certain inward compressive force in the initial stage. During high-speed operation, the inward compressive force applied to the magnetic ring by the magnetic sleeve offsets part of the centrifugal force generated by the magnetic ring during high-speed operation, thereby reducing the actual force on the magnetic ring during operation, greatly reducing the destructive force on the magnetic ring, and thus ensuring the stable operation of the magnetic ring and preventing motor failure.

[0006] In a further improvement, the magnetic sleeve may preferably include a magnetic conductor and a balance ring. The magnetic conductor is connected to the rotating shaft and sleeved on the stator assembly. The magnetic ring is connected to the magnetic conductor, and the balance ring is sleeved on the magnetic conductor. This results in more balanced rotation of the magnetic sleeve and a longer service life.

[0007] In a further improvement, a wear-resistant sheet may preferably be sandwiched between the magnetic conductor and the bearing body.

[0008] As an improvement, the stator assembly preferably includes a bearing housing, a core winding, an upper bearing, an elastic washer, and a lower bearing. The upper and lower bearings are disposed in the bearing housing, and the elastic washer is disposed between the bottom of the upper bearing and the bottom surface of the upper bearing mounting cavity of the bearing housing. The bearing housing is connected to the volute, the core winding is sleeved on the bearing housing, and the rotating shaft passes through the upper and lower bearings in sequence. The structure is compact.

[0009] Further improvements include the option to leave a gap between the rotating shaft and the inner ring of the upper bearing, and a gap between the rotating shaft and the inner ring of the lower bearing. This gap-fitting assembly naturally forms a wedge-shaped structure between the outer diameter of the lower rotating shaft and the inner ring of the bearing. During high-speed operation, the wedge-shaped gap between the rotating shaft and the inner ring of the bearing creates a state similar to a pneumatic suspension bearing, significantly improving the motor's operational stability, completely avoiding the problems of adhesive fits and interference fits, extending the bearing's service life, and reducing rotating shaft noise. Simultaneously, the pneumatic suspension bearing configuration reduces bearing friction, improving the efficiency of the entire operating system.

[0010] A further improvement is made by preferably providing a groove on the outer wall of the shaft corresponding to the upper bearing. The limiting member is preferably a limiting spring that is locked in the groove, and the limiting spring abuts against the inner ring of the upper bearing. The structure is simple and the limiting effect is good.

[0011] As an improvement, a connecting plate can preferably be provided on the volute, the connecting plate being connected to the stator assembly, and an insulating gasket is provided on the connecting plate, with the circuit board connected to the insulating gasket. This results in a more compact structure and reduces the size of the fan.

[0012] As an improvement, the volute can preferably include an upper housing and a lower housing, which are connected by a snap-fit ​​device on the outer wall of the volute. This facilitates the disassembly and installation of the fan.

[0013] As an improvement, a limiting groove can preferably be provided at the air inlet of the volute, and an impeller protrusion ring that can extend into the limiting groove is provided on the top of the impeller. Reducing the gap between the impeller and the volute results in better sealing of the exhaust chamber, higher air guiding efficiency, and is more conducive to increasing the vacuum level of the fan.

[0014] Compared with the prior art, the advantages of this utility model are as follows: the end of the rotating shaft is connected to the magnetic sleeve, the magnetic ring is fixed inside the magnetic sleeve, the magnetic sleeve is sleeved on the stator assembly, the magnetic ring corresponds to the iron core winding of the stator assembly, and the magnetic sleeve is sleeved outside the stator assembly. The centrifugal force of the magnetic sleeve on the rotating shaft is greater, the efficiency of the rotating shaft speed is higher, which helps to increase the rotating shaft speed, thereby speeding up the impeller rotation and improving the vacuum degree of the fan; the number of blades of the impeller is greater than 9, the impeller has more stable control over the fluid, and the fluid efficiency is higher; in summary, this structure can increase the vacuum degree of the turbine fan to 30-35 kPa, which is higher than the vacuum degree of the fans in the prior art. Attached Figure Description

[0015] Figure 1 This is a perspective view of an embodiment of the present utility model;

[0016] Figure 2 for Figure 1 Side projection view;

[0017] Figure 3 yes Figure 2 Cross-sectional view along line AA;

[0018] Figure 4 yes Figure 2 Cross-sectional view along the BB line;

[0019] Figure 5 yes Figure 1 A bottom view;

[0020] Figure 6 yes Figure 5 Cross-sectional view along the CC line;

[0021] Figure 7 yes Figure 1 A cross-sectional view of the rotor assembly along its central axis, showing the stress state of the magnetic ring in a stationary state;

[0022] Figure 8 yes Figure 7 A cross-sectional view showing the force state of the magnetic ring after the rotor assembly rotates;

[0023] Figure 9 yes Figure 1 Exploded structural diagram;

[0024] Figure 10 yes Figure 9 Further structural decomposition diagram;

[0025] Figure 11 yes Figure 1 A three-dimensional view from another angle;

[0026] Figure 12 yes Figure 11 Exploded structural diagram;

[0027] Figure 13 yes Figure 10 An exploded view of the rotor assembly and impeller (not fully disassembled).

[0028] Figure 14 yes Figure 12 Exploded view of the connection structure between the middle stator assembly and the circuit board;

[0029] Figure 15 yes Figure 6 Enlarged view of section I;

[0030] Figure 16 yes Figure 6 Enlarged view of Part II;

[0031] Figure 17 yes Figure 16 The diagram shows the structural relationship between the rotating shaft and the inner ring of the bearing.

[0032] Figure 18 yes Figure 6 Enlarged view of Part III. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] like Figures 1 to 18 As shown, the volute fan for a sweeper in this embodiment includes a volute 1, an impeller 2, a rotor assembly, a stator assembly, and a circuit board 3. The impeller 2 is disposed in the inner cavity of the volute 1. The stator assembly and the circuit board 3 are connected to the volute 1. The iron core winding 51 of the stator assembly is connected to the circuit board 3 through wires. The specific circuit structure of the circuit board 3 and the specific principle by which the circuit board 3 controls the stator assembly to drive the rotor assembly to rotate are known technologies and will not be described in detail here.

[0035] The rotor assembly includes a shaft 4, a magnetic ring 41, a magnetic sleeve, and a limiting member 44. The shaft 4 passes through the bearing housing of the stator assembly. The limiting member connects the shaft 4 and the bearing housing. One end of the shaft 4 passes through the volute 1 and connects to the impeller 2. The other end of the shaft 4 is connected to the magnetic sleeve. The magnetic ring 41 is fixed inside the magnetic sleeve, which is fitted onto the stator assembly. The magnetic ring 41 corresponds to the iron core winding 51 of the stator assembly. The impeller 2 has more than 9 blades 21. The magnetic sleeve and the magnetic ring 41 are connected together by an interference fit. The inner diameter of the magnetic sleeve is 0.05–0.1 mm smaller than the outer diameter of the magnetic ring 41. The magnetic sleeve includes a magnetic conductor 42 and a balance ring 43. The magnetic conductor 42 is connected to the shaft 4 and fitted onto the stator assembly. The magnetic ring 41 is connected inside the magnetic conductor 42, and the balance ring 43 is fitted onto the magnetic conductor 42. A wear-resistant sheet 45 is sandwiched between the magnetic conductor 42 and the bearing body.

[0036] The stator assembly includes a bearing housing 5, an iron core winding 51, an upper bearing 52, an elastic washer 53, and a lower bearing 54. The upper bearing 52 and lower bearing 54 are housed within the bearing housing 5. The elastic washer 53 is positioned between the bottom of the upper bearing 52 and the bottom surface of the upper bearing mounting cavity of the bearing housing 5. Damping grease is applied between the upper bearing 52 and the upper bearing mounting cavity. The bearing housing 5 is connected to the volute 1. The iron core winding 51 is fitted onto the bearing housing 5. The rotating shaft 4 passes through the upper bearing 52 and the lower bearing 54 sequentially. A gap 50 is maintained between the rotating shaft 4 and the inner ring of the upper bearing 52, and a gap 50 is maintained between the rotating shaft 4 and the inner ring of the lower bearing 54. A groove 40 is provided on the outer wall of the rotating shaft 4 corresponding to the upper bearing 52. A limiting member 44 is a limiting spring that engages in the groove 40, and the limiting spring contacts the inner ring of the upper bearing 52.

[0037] A connecting plate 11 is provided on the volute 1. The connecting plate 11 is connected to the stator assembly. An insulating gasket 12 is provided on the connecting plate 11. The circuit board 3 is connected to the insulating gasket 12.

[0038] The stator assembly is assembled as follows: the bearing housing 5 is made of copper sleeve, and the circuit board 3 is interference-fitted with the copper sleeve. Insulating gasket 12 has corresponding through holes on the circuit board 3. The circuit board 3, insulating gasket 12, and connecting plate 11 are riveted together to fix the circuit board 3. The copper sleeve passes through the through hole in the middle of the fixing structure of the circuit board 3, insulating gasket 12, and connecting plate 11. The lower bearing 54 is installed in the copper sleeve, and the outer ring of the bearing is glued to the mounting cavity of the copper sleeve. An elastic gasket 53, i.e., a wave spring, is placed in, and the upper bearing 52 is pressed in. Damping grease is applied between the upper bearing 52 and the upper bearing mounting cavity. Then, the wound stator core, i.e., the core winding 51, is pressed in. The stator core and bearing housing 5 are interference-fitted. This completes the installation of the stator assembly.

[0039] The volute 1 includes an upper housing 10 and a lower housing, which are connected by a snap-fit ​​device on the outer wall of the volute. A limiting groove 13 is provided at the air inlet 101 of the volute 1, and an impeller protrusion 22 is provided on the top of the impeller 2, which can extend into the limiting groove 13. The air outlet 102 of the volute 1 is located on the side wall of the volute 1.

[0040] Rotor assembly assembly: The magnetic conductor 42 is interference-fitted with the balance ring 43, then the rotating shaft 4 is interference-fitted with the magnetic conductor 42, the magnetic ring 41 is interference-fitted with the magnetic conductor ring, i.e. the magnetic conductor 42, and then the wear-resistant plate 45 is placed on the rotating shaft to form the rotor assembly.

[0041] When the rotor assembly and stator assembly are combined, the rotating shaft 4 passes through the inner rings of the upper and lower bearings and is engaged with a limiting snap ring to fix the axial movement of the rotor assembly. The limiting snap ring is fixed in the slot 40 between the inner ring of the upper bearing and the rotating shaft 4.

[0042] The motor body is now complete. The motor body is fixed to the bottom of the lower housing of the volute 1 by the three screw holes on circuit board 3 engaging with the three screw holes on the volute base. The shaft 4 passes through the hole in the center of the bottom of the volute and presses in the impeller 2. The impeller 2 and shaft 4 are interference-fitted. Then, the upper housing 10 of the volute 1 is installed. The upper housing 10 uses four snap-fit ​​pieces to engage with four protruding structures on the lower housing, thus securing and fitting the volute 1. The specific structure of the snap-fit ​​pieces and the specific principle of the engagement between the snap-fit ​​pieces and the protruding structures are known technologies and will not be described in detail. The motor assembly is now complete.

[0043] Working principle: The magnetic sleeve is fitted onto the stator assembly, and the magnetic ring corresponds to the iron core winding of the stator assembly. Since the magnetic sleeve is outside the stator assembly, it exerts a greater centrifugal force on the shaft, resulting in a higher shaft speed and efficiency improvement. This helps to increase the shaft speed, thereby accelerating the impeller rotation and improving the fan vacuum. The impeller has more than nine blades, resulting in more stable fluid control and higher fluid efficiency. Overall, this structure can increase the vacuum of the turbine fan to 30–35 kPa.

[0044] Traditional solutions employ either adhesive bonding between the shaft and the bearing inner ring or an interference fit between the shaft and the bearing inner ring. However, both of these methods have problems when operating at high speeds and high vacuum levels.

[0045] Adhesive bonding: When the motor is running at high speed, the high temperature generated by the bearing causes the adhesive between the shaft and the inner wall of the bearing to fail due to the high temperature. The failed adhesive will cause the bearing to fail and the product to become noisier when the motor is running at high speed, which will eventually lead to product failure.

[0046] Interference fit: In the assembly of shafts and bearings, it is difficult to control the interference amount when using an interference fit. Excessive interference force often occurs during assembly, causing the inner ring of the support to expand outwards, leading to bearing damage. Insufficient interference amount results in an unreliable connection, causing the shaft to wobble within the bearing, generating noise and vibration, and ultimately leading to product failure.

[0047] This patented solution employs a clearance fit between the shaft and the bearing inner ring. The shaft machining accuracy is controlled within 2.993±0.001 mm, and the bearing inner ring accuracy is 4 to 2.995 mm, ensuring that the two are in a clearance fit. Under this clearance fit, the outer diameter of the shaft and the inner ring of the bearing naturally form a wedge-shaped structure. Figure 17 The dashed line divides the 50mm gap into an upper and lower section, with the lower section being wedge-shaped. The shaft rotates at high speed driven by the motor. During operation, the wedge-shaped gap between the shaft and the inner ring of the bearing creates a state similar to a pneumatic suspension bearing, significantly improving the motor's operational stability and completely avoiding issues related to adhesive fits and interference fits. Simultaneously, the pneumatic suspension bearing configuration reduces bearing friction, improving the efficiency of the entire operating system.

[0048] In traditional designs, the magnetic ring and the magnetic conductor ring (i.e., the magnetic conductor) are glued together. However, this glued connection inevitably creates a gap between the magnetic ring and the magnetic conductor ring. During high-speed operation of the motor (≥80000rpm), both the magnetic ring and the magnetic conductor ring are subjected to a huge centrifugal force F2. Due to the gap between the magnetic ring and the magnetic conductor ring, and the fact that the magnetic ring is not as strong as the magnetic conductor ring (a metal part), the magnetic ring may break or explode during operation, leading to motor failure.

[0049] This technical solution involves controlling the interference fit between the magnetic ring and the conductive ring to be 0.05–0.1 mm, so that the magnetic ring initially withstands a certain inward compressive force F1. Figure 7 As shown, during high-speed operation, the inward compressive force applied by the magnetic guide ring to the magnetic ring partially offsets the centrifugal force F2 generated by the high-speed operation of the magnetic ring, such as... Figure 8 As shown, this ensures that the actual force on the magnetic ring during operation is the difference between F2 and F1, greatly reducing the destructive force on the magnetic ring, thereby ensuring stable operation of the magnetic ring and preventing motor failure.

Claims

1. A volute fan for a sweeper, comprising a volute (1), an impeller (2), a rotor assembly, a stator assembly, and a circuit board (3), wherein the impeller (2) is disposed in the inner cavity of the volute (1), the stator assembly and the circuit board (3) are connected to the volute (1), and the iron core winding (51) of the stator assembly is connected to the circuit board (3) via a wire, characterized in that: The rotor assembly includes a rotating shaft (4), a magnetic ring (41), a magnetic sleeve, and a limiting member (44). The rotating shaft (4) is mounted on the bearing body of the stator assembly. The limiting member connects the rotating shaft (4) and the bearing body. One end of the rotating shaft (4) passes through the volute (1) and is connected to the impeller (2). The other end of the rotating shaft (4) is connected to the magnetic sleeve. The magnetic ring (41) is fixed inside the magnetic sleeve. The magnetic sleeve is fitted on the stator assembly. The magnetic ring (41) corresponds to the iron core winding (51) of the stator assembly. The impeller (2) has more than 9 blades (21).

2. The volute fan according to claim 1, characterized in that: The magnetic sleeve is connected to the magnetic ring (41) by an interference fit, and the inner diameter of the magnetic sleeve is 0.05 to 0.1 mm smaller than the outer diameter of the magnetic ring (41).

3. The volute fan according to claim 2, characterized in that: The magnetic sleeve includes a magnetic conductor (42) and a balance ring (43). The magnetic conductor (42) is connected to the rotating shaft (4) and is sleeved on the stator assembly. The magnetic ring (41) is connected inside the magnetic conductor (42) and the balance ring (43) is sleeved on the magnetic conductor (42).

4. The volute fan according to claim 3, characterized in that: A wear-resistant sheet (45) is sandwiched between the magnetic conductor (42) and the bearing body.

5. The volute fan according to any one of claims 1 to 4, characterized in that: The stator assembly includes a bearing housing (5), an iron core winding (51), an upper bearing (52), an elastic washer (53), and a lower bearing (54). The upper bearing (52) and the lower bearing (54) are disposed in the bearing housing (5). The elastic washer (53) is disposed between the bottom of the upper bearing (52) and the bottom surface of the upper bearing mounting cavity of the bearing housing (5). The bearing housing (5) is connected to the volute (1). The iron core winding (51) is sleeved on the bearing housing (5). The rotating shaft (4) passes through the upper bearing (52) and the lower bearing (54) in sequence.

6. The volute fan according to claim 5, characterized in that: A gap (50) is left between the rotating shaft (4) and the inner ring of the upper bearing (52), and a gap (50) is left between the rotating shaft (4) and the inner ring of the lower bearing (54).

7. The volute fan according to claim 5, characterized in that: A groove (40) is provided on the outer wall of the rotating shaft (4) corresponding to the upper bearing (52). The limiting member (44) is a limiting snap ring that is locked in the groove (40). The limiting snap ring is in contact with the inner ring of the upper bearing (52).

8. The volute fan according to any one of claims 1 to 4, characterized in that: The volute (1) is provided with a connecting plate (11), which is connected to the stator assembly. An insulating gasket (12) is provided on the connecting plate (11), and the circuit board (3) is connected to the insulating gasket (12).

9. The volute fan according to any one of claims 1 to 4, characterized in that: The volute (1) includes an upper shell (10) and a lower shell, which are connected by a snap fastener on the outer wall of the volute.

10. The volute fan according to any one of claims 1 to 4, characterized in that: A limiting groove (13) is provided at the air inlet (101) of the volute (1), and an impeller protrusion (22) that can extend into the limiting groove (13) is provided on the top of the impeller (2).

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