Assembly structure of rotating shaft and rotor shell of hub motor

Abstract

The utility model discloses a rotating shaft and rotor housing assembly structure of a hub motor, which comprises a rotor housing and a rotating shaft, a shaft hole is formed in the center of the rotor housing, a shaft sleeve protruding inwards is formed on the inner side of the shaft hole, and a sleeve opening of the shaft sleeve and the shaft hole have the same specification and are coaxially matched with each other. A limiting convex ring and a rough part are formed at the bottom end of the rotating shaft, the rotating shaft penetrates through the shaft hole and the shaft sleeve in a stamping manner, the limiting convex ring is in limiting fit with the shaft hole, and the rough part is in interference fit with the inner wall of the shaft sleeve, so that coaxial connection between the rotating shaft and the rotor shell is realized. Compared with the prior art, the assembly difficulty and speed of the rotating shaft and the rotor shell are simplified, the connection strength is improved, and the service life of the product is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of hub motor technology, and in particular to the assembly structure of the hub motor shaft and rotor housing. Background Technology

[0002] Robotic vacuum cleaners, as intelligent cleaning devices, are widely used in modern homes. However, existing assembly structures for the hub motor shaft and rotor housing in robotic vacuum cleaners have several problems. Some use threaded or pin connections, resulting in complex structures with numerous parts, increasing production and assembly costs and making later maintenance more difficult. Others use simple clearance fits, which, during long-term operation, are prone to loosening and displacement between the shaft and rotor housing due to vibration, load changes, and other factors. This leads to increased motor noise, unstable power transmission, and other problems, severely affecting the lifespan and cleaning performance of the robotic vacuum cleaner. Therefore, improvements are necessary. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide an assembly structure for the shaft and rotor housing of a hub motor, which can be assembled by stamping, and has the characteristics of high connection strength and fast assembly.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a hub motor shaft and rotor housing assembly structure, including a rotor housing and a shaft, a shaft hole is formed at the center of the rotor housing, and an inwardly protruding bushing is formed on the inner side of the shaft hole. The bushing opening has the same specifications as the shaft hole, and the two are coaxially fitted. A limiting protrusion ring and a rough part are formed at the bottom end of the shaft. The shaft is inserted into the shaft hole and the bushing by stamping. The limiting protrusion ring is limited and fitted with the shaft hole, and the rough part is interference fitted with the inner wall of the bushing to achieve coaxial connection between the shaft and the rotor housing.

[0005] In a further technical solution, the rough part includes a rough surface structure formed on the outer surface of the rotating shaft, and the rough surface structure consists of multiple regularly distributed protrusions or depressions.

[0006] In a further technical solution, the width d of the rough surface structure is 5mm-15mm, and the width d is not greater than the length of the bushing.

[0007] In a further technical solution, the rough surface structure includes multiple convex strips distributed along the circumferential direction, and the cross-sectional shape of the convex strips is triangular.

[0008] In a further technical solution, the width of the convex strip is 0.3mm-0.5mm and the height is 0.1mm-0.2mm.

[0009] In a further technical solution, a partition groove is formed in the middle of the shaft for limiting the assembly of the cover plate of the hub motor; a gear connecting rod is provided at the upper end of the shaft, the outer diameter of the gear connecting rod is smaller than the outer diameter of the shaft, and the connection between the two forms an end cover limiting boss; the total length of the shaft is 8cm-15cm.

[0010] In a further technical solution, the two sides of the middle part of the gear connecting rod are milled to form cuts, which extend along their axial direction and to the top of the gear connecting port to form a gear insertion key with an irregular cross-sectional shape.

[0011] In a further technical solution, a groove is formed in the middle of the gear insertion key for assembling the snap ring unit.

[0012] In a further technical solution, the top surface of the rotor housing is formed by stamping multiple reinforcing ribs that protrude inwards, and each reinforcing rib is spaced apart along the circumferential direction.

[0013] In a further technical solution, the reinforcing ribs extend along the circumference, and each reinforcing rib has the same forming specifications, with a distribution radius of 2cm-4cm; the inner side arc length of each reinforcing rib is 5mm-20mm, the thickness of the reinforcing rib is 1mm-2mm, and the width of the reinforcing rib is 3mm-8mm.

[0014] The advantages of this invention compared to the prior art after adopting the above structure are:

[0015] 1. This assembly structure directly connects the rotating shaft to the rotor housing through an interference fit, eliminating the need for additional complex connecting parts (such as bolts, nuts, pins, etc.), greatly reducing the number of parts and making the entire hub motor structure more compact. This saves space inside the robot vacuum cleaner and facilitates the rational layout and installation of other components.

[0016] 2. The larger radial pressure and friction generated by the interference fit, combined with the progressive limiting effect of the circumferentially distributed convex strips, can more effectively transmit torque and axial force during motor operation. Even under conditions such as long-term operation, frequent start-stop, and encountering complex ground conditions (e.g., climbing slopes, overcoming obstacles), it ensures a tight connection between the shaft and the rotor housing, greatly reducing the possibility of loosening and displacement, thereby improving the stability and reliability of motor operation and extending the motor's service life. The uniform force distribution characteristic of the convex strip structure further enhances the stability of the connection compared to irregular rough surfaces.

[0017] 3. Compared to traditional threaded or pin connections, this assembly structure uses a stamping interference fit connection process, which is relatively simple to operate and does not require complex assembly tools or high-precision assembly skills. During the production process, the shaft and rotor housing only need to be simply positioned, and then the connection can be completed in one stamping operation using a stamping machine. This greatly shortens the assembly time, improves production efficiency, and reduces production costs. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is an exploded view of the present invention.

[0020] Figure 2 This is a cross-sectional schematic diagram of the present invention.

[0021] Figure 3 This is a schematic diagram of the rotating shaft in this utility model. Detailed Implementation

[0022] The following are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention.

[0023] To address the shortcomings of the existing assembly structure between the shaft and rotor housing of hub motors and improve its connection strength and assembly speed, the inventors proposed an assembly structure for the shaft and rotor housing with high concentricity achieved through stamping.

[0024] like Figures 1 to 3 As shown, the hub motor's shaft and rotor housing assembly structure includes a rotor housing 2 and a shaft 1. A shaft hole 20 is formed at the center of the rotor housing 2. An inwardly protruding bushing 21 is formed on the inner side of the shaft hole 20. The bushing 21 has the same specifications as the shaft hole 20 and the two are coaxially fitted. A limiting protrusion ring 14 and a rough portion 13 are formed at the bottom end of the shaft 1. The shaft 1 is inserted into the shaft hole 20 and the bushing 21 by stamping. The limiting protrusion ring 14 is fitted with the shaft hole 20 for limiting, and the rough portion 13 is press-fitted with the inner wall of the bushing 21 to achieve a coaxial connection between the shaft 1 and the rotor housing 2.

[0025] The interference fit directly connects the rotating shaft 1 to the rotor housing 2, eliminating the need for additional complex connecting parts such as bolts, nuts, and pins. This greatly reduces the number of parts, making the entire hub motor structure more compact, saving internal space in the robot vacuum cleaner, and facilitating the rational layout and installation of other components.

[0026] This assembly structure employs a stamping interference fit connection process, which is relatively simple to operate and does not require complex assembly tools or high-precision assembly skills. During the production process, the shaft 1 and rotor housing 2 only need to be simply positioned, and then the connection can be completed in one stamping operation using a stamping machine. This greatly shortens the assembly time, improves production efficiency, and reduces production costs.

[0027] Specifically, the rough portion 13 includes a rough surface structure formed on the outer surface of the rotating shaft 1, which consists of multiple regularly distributed protrusions or depressions.

[0028] Specifically, the width d of the rough surface structure is 8mm, and the width d is not greater than the length of the bushing 21.

[0029] Specifically, the rough surface structure includes multiple raised strips distributed along the circumference, and the cross-sectional shape of the raised strips is triangular.

[0030] Specifically, the width of the convex strip is 0.35mm and the height is 0.15mm.

[0031] The large radial pressure and friction generated by the interference fit, combined with the progressive limiting effect of the circumferentially distributed convex strips, can more effectively transmit torque and axial force during motor operation. Even during long-term operation, frequent starts and stops, and complex ground conditions such as climbing slopes and overcoming obstacles, it ensures a tight connection between the shaft and the rotor housing, greatly reducing the possibility of loosening and displacement. This improves the stability and reliability of motor operation and extends the motor's lifespan. The uniform force distribution characteristic of the convex strip structure further enhances the stability of the connection compared to irregular rough surfaces.

[0032] Specifically, a partition groove 10 is formed in the middle of the rotating shaft 1 for limiting the assembly of the cover plate of the hub motor; a gear connecting rod 11 is provided at the upper end of the rotating shaft 1, the outer diameter of the gear connecting rod 11 is smaller than the outer diameter of the rotating shaft 1, and the connection between the two forms an end cover limiting boss 12; the total length of the rotating shaft 1 is 12cm.

[0033] Specifically, the gear connecting rod 11 has milled notches on both sides of its middle section, extending along its axial direction to the top of the gear connecting port to form an irregularly shaped gear insertion key 111. The gear insertion key 111 is used to assemble the drive gear 3, and the drive gear 3 has a matching socket 30 at its center. The extended rotating shaft 1 facilitates the robot vacuum cleaner to use the hub motor for other functions, improving the utilization efficiency of the power source.

[0034] Specifically, the gear key 111 has a groove 112 formed in the middle for assembling the snap ring unit 4. By creating a snap ring unit 4 in the groove 112 to limit the axial position of the drive gear 3, assembly is simple, safe and reliable.

[0035] Specifically, the top surface of the rotor housing 2 is formed by stamping multiple reinforcing ribs 22 that protrude inwards, and each reinforcing rib 22 is spaced apart along the circumferential direction.

[0036] Specifically, the reinforcing ribs 22 extend along the circumferential direction, and each reinforcing rib 22 has the same molding specifications, with a distribution radius of 2cm-4cm; the inner side arc length of each reinforcing rib 22 is 5mm-20mm, the thickness of the reinforcing rib 22 is 1mm-2mm, and the width of the reinforcing rib 22 is 3mm-8mm.

[0037] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. An assembly structure of a rotating shaft of a wheel hub motor and a rotor housing, comprising a rotor housing (2) and a rotating shaft (1), characterized in that: The center of the rotor shell (2) is formed with an axle hole (20), the inner side of the axle hole (20) is formed with an axle sleeve (21) protruding inward, the sleeve opening of the axle sleeve (21) is the same specification as the axle hole (20), and the two are coaxially matched, The bottom end of the rotating shaft (1) is formed with a limiting convex ring (14) and a rough part (13), the rotating shaft (1) is connected to the axle hole (20) and the axle sleeve (21) by stamping, the limiting convex ring (14) is limitedly matched with the axle hole (20), and the rough part (13) is matched with the inner wall of the axle sleeve (21) in an interference fit, so as to realize the coaxial connection between the rotating shaft (1) and the rotor shell (2).

2. The rotating shaft and rotor housing assembly of the in-wheel motor according to claim 1, characterized by: The rough part (13) includes a rough surface structure formed on the outer surface of the rotating shaft (1), and the rough surface structure is composed of a plurality of regular protrusions or recesses.

3. The rotating shaft and rotor housing assembly of a wheel hub motor according to claim 2, characterized in that: The width d of the rough surface structure is 5mm-15mm, and the width d is not greater than the length of the axle sleeve (21).

4. The rotating shaft and rotor housing assembly of a wheel motor according to claim 3, characterized in that: The rough surface structure includes a plurality of convex strips arranged in the circumferential direction, and the cross-sectional shape of the convex strip is triangular.

5. The rotating shaft and rotor housing assembly of a wheel motor according to claim 4, characterized in that: The width of the convex strip is 0.3mm-0.5mm, and the height is 0.1mm-0.2mm.

6. The rotating shaft and rotor housing assembly of a wheel motor according to claim 1, characterized in that: The middle position of the rotating shaft (1) is formed with a separation groove (10) for limiting assembly of the cover plate of the hub motor; the upper end of the rotating shaft (1) is provided with a gear connecting rod (11), the outer diameter of the gear connecting rod (11) is smaller than the outer diameter of the rotating shaft (1), and the connecting part of the two forms an end cover limiting boss (12); the total length of the rotating shaft (1) is 8cm-15cm.

7. The rotating shaft and rotor housing assembly of a wheel motor according to claim 6, characterized in that: The middle part of the gear connecting rod (11) is respectively formed with a notch by milling, the notch extends along the axial direction and extends to the top end of the gear connecting port, so as to form an irregular cross-sectional shape of the gear plug key (111).

8. The rotating shaft and rotor housing assembly of a wheel hub motor according to claim 7, characterized in that: The middle part of the gear plug key (111) is formed with a clamping groove (112) for assembling a clamping spring unit (4).

9. The rotating shaft and rotor housing assembly of a wheel motor according to claim 1, characterized in that: The top surface of the rotor shell (2) is formed with a plurality of reinforcing ribs (22) protruding inward by stamping, and each reinforcing rib (22) is arranged at intervals in the circumferential direction.

10. The rotating shaft and rotor housing assembly of a wheel hub motor according to claim 9, characterized in that: The reinforcing ribs (22) are arranged in the circumferential direction, each reinforcing rib (22) is formed with the same specification, and the radius of the distribution track is 2cm-4cm; The arc length of the inner side of each reinforcing rib (22) is 5mm-20mm, the thickness of the reinforcing rib (22) is 1mm-2mm, and the width of the reinforcing rib (22) is 3mm-8mm.

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