Electric bicycle rear wheel motor waterproof and dustproof sealing assembly

Abstract

The utility model discloses a kind of waterproof dustproof sealing assembly of electric bicycle rear wheel motor, including from inside to outside in turn around motor shaft nested arrangement: magnetic fluid sealing layer: including annular permanent magnet, the gradient magnetic field gap between motor shaft and the end cover of motor and the magnetic fluid filled in gap, annular permanent magnet is embedded in motor end cover inner wall, the inner peripheral surface of annular permanent magnet and motor shaft form radial gap cooperation;Dynamic lip seal layer: including with the main lip of motor shaft interference fit, with the secondary lip of end cover contact, and the wave spring of abutting main lip back;Dust layer: be located at the opening of motor's end cover outside, including detour passage and oblique air guide hole;Hydrophobic flow guide layer: cover on the outer surface of motor's end cover, including V-shaped groove and flow guide fin, the end of flow guide fin extends into the hub spoke mounting groove of electric bicycle. The utility model can realize the multistage collaborative sealing of motor, improve sealing effect.

Description

Technical Field

[0001] This utility model relates to the field of sealing technology, and in particular to a waterproof and dustproof sealing component for the rear wheel motor of an electric bicycle. Background Technology

[0002] The motor is one of the core components of an electric bicycle. To extend its lifespan, it requires waterproofing and dustproofing. Current motor dustproofing and waterproofing structures typically use a single-layer rubber ring, which is prone to aging and seal failure. Furthermore, the lack of an active drainage system allows mud and sand to easily penetrate the motor's interior due to its high-speed rotation.

[0003] Therefore, there is an urgent need to research and develop a waterproof and dustproof sealing component for the rear wheel motor of an electric bicycle to solve the above-mentioned technical problems. Summary of the Invention

[0004] The purpose of this utility model is to provide a waterproof and dustproof sealing component for the rear wheel motor of an electric bicycle. This waterproof and dustproof sealing component for the rear wheel motor of an electric bicycle can achieve multi-stage coordinated sealing of the motor and improve the sealing effect.

[0005] To achieve the above objectives, the present invention provides a waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle, the specific implementation of which is as follows:

[0006] The waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle includes a magnetic fluid sealing layer, a dynamic lip sealing layer, a dustproof layer, and a hydrophobic guiding layer, which are nested around the motor shaft from the inside to the outside.

[0007] The magnetic fluid sealing layer includes an annular permanent magnet, a gradient magnetic field gap located between the motor shaft and the motor end cover, and magnetic fluid filling the gap. The annular permanent magnet is embedded in the inner wall of the motor end cover, and the inner circumferential surface of the annular permanent magnet forms a radial clearance fit with the motor shaft.

[0008] The dynamic lip seal layer includes a main lip that is interference-fitted with the motor shaft, a secondary lip that contacts the end cap, and a wave spring that abuts against the back of the main lip.

[0009] The dustproof layer is located at the opening on the outside of the motor end cover. The dustproof layer includes a three-level detour channel with decreasing height and an oblique air guide hole that penetrates the end cover of the motor. The entrance of the detour channel is directly opposite to the rotation direction of the electric bicycle wheel hub.

[0010] The hydrophobic guide layer covers the outer surface of the motor end cover and includes several V-shaped grooves and at least one guide vane. The end of the guide vane extends into the hub spoke mounting groove of the electric bicycle.

[0011] This utility model discloses a waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle. Compared with the prior art, it achieves multi-level synergistic sealing within the limited axial space of the motor shaft by using a magnetic fluid sealing layer, a dynamic lip sealing layer, a dustproof layer, and a hydrophobic guiding layer nested around the motor shaft from the inside out. Compared with the single-layer rubber ring sealing structure in the prior art, the multi-layer sealing structure of this application can still maintain the dustproof and waterproof sealing of the motor even if one or two layers of the sealing structure fail, thus improving the sealing effect of the motor.

[0012] In some embodiments, the magnetohydrodynamic sealing layer, dynamic lip sealing layer, dustproof layer, and hydrophobic guide layer are stacked sequentially along the axial direction of the motor shaft, with a total thickness of ≤18mm. The axial distance between the magnetohydrodynamic sealing layer and the dynamic lip sealing layer is 3-5mm, and the end of the guide vane is ≤2mm from the edge of the hub spoke mounting groove.

[0013] By setting the axial spacing between the magnetohydrodynamic sealing layer and the dynamic lip sealing layer to 3-5mm, and the distance from the end of the guide vane to the edge of the hub spoke mounting groove to ≤2mm, the sealing structure is constrained within a limited space.

[0014] In some embodiments, the axial width of the gradient magnetic field gap is 0.15-0.25 mm, the permanent magnet is an N50-N52 grade neodymium iron boron magnet, the distance between two adjacent magnetic poles is ≤2 mm, and the magnetic field strength gradient between two adjacent magnetic poles is ≥400 T / m.

[0015] In some embodiments, the magnetic fluid has a saturation magnetization of 450-G and a viscosity of 280-320 mPa·s.

[0016] By combining a gradient magnetic field with a high-viscosity magnetic fluid, axial migration of the magnetic fluid under centrifugal force is prevented, ensuring that the leakage rate is <0.1mL / 100h when the rotation speed is ≤3000rpm.

[0017] In some embodiments, the interference fit between the main lip and the motor shaft is 0.25-0.35 mm, the lip tip angle is 55°-65°, and the contact width with the motor shaft is 0.2-0.3 mm; the initial compression of the wave spring is 12%-18%, and the spring wire diameter is 0.5-0.7 mm.

[0018] By using the interference fit between the main lip and the motor shaft, and the preload of the wave spring, the lip contact pressure of the main lip is stabilized at 0.7-0.9MPa, compensating for the risk of seal failure when the radial runout of the shaft is ±0.4mm.

[0019] In some embodiments, the height junctions of the detour channels are connected by a 120° bend.

[0020] In some embodiments, the surface roughness Ra of the inner wall of the meandering channel is ≤0.15μm.

[0021] By setting the high-altitude junction of the detour channel to a 120° bend angle, the low roughness of the inner wall surface of the detour channel is combined with the low roughness to reduce the particle adhesion rate and improve the interception efficiency of PM10 and above dust.

[0022] In some embodiments, the air guide vanes are arranged in a spiral at an angle of 12°-15°, and the spacing between adjacent air guide vanes is 1 / 6-1 / 8 of the hub circumference.

[0023] In some embodiments, the V-groove has a depth of 40-60 μm and a width of 150-250 μm, and a fluorosilane coating is applied to the surface of the V-groove.

[0024] By using guide vanes arranged in a spiral at an angle of 12°-15°, and by generating a synergistic airflow effect between the guide vanes and the hub rotation, the amount of residual water film on the surface is reduced. The V-groove structure is coated with a fluorosilane coating to improve hydrophobic durability.

[0025] Based on the above technical solution, this utility model has the following beneficial effects compared with the prior art:

[0026] By employing a magnetic fluid sealing layer, a dynamic lip sealing layer, a dustproof layer, and a hydrophobic guiding layer nested around the motor shaft from the inside out, a multi-level synergistic seal is achieved within the limited axial space of the motor shaft. Compared to the single-layer rubber ring sealing structure in the prior art, the multi-layer sealing structure of this application can still maintain the dustproof and waterproof seal of the motor even if one or two layers of the sealing structure fail, thus improving the sealing effect of the motor. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of this utility model;

[0028] Figure 2 This is a cross-sectional schematic diagram of the present invention;

[0029] Figure 3 For the present utility model Figure 2 A magnified view of a portion of the image.

[0030] Explanation of reference numerals in the attached figures:

[0031] 100. Motor; 110. Motor shaft; 120. End cap; 130. Spoke mounting groove; 200. Magnetofluid sealing layer; 210. Ring permanent magnet; 220. Gradient magnetic field gap; 300. Dynamic lip sealing layer; 310. Main lip; 320. Secondary lip; 330. Wave spring; 400. Dustproof layer; 410. Detour channel; 420. Angled air guide hole; 510. Air guide vane; 520. V-groove. Detailed Implementation

[0032] To facilitate understanding of this utility model, the specific embodiments of this utility model will be described in more detail below with reference to the accompanying drawings.

[0033] Unless otherwise specified or defined, the terms "first," "second," etc., used in this document are for distinguishing names only and do not represent a specific number or order.

[0034] Unless otherwise stated or defined, the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0035] It should be noted that in this article, "fixed to" or "connected to" can mean directly fixed to or connected to a component, or indirectly fixed to or connected to a component.

[0036] like Figure 1-3 As shown, the waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle provided in this embodiment includes a magnetic fluid sealing layer 200, a dynamic lip sealing layer 300, a dustproof layer 400, and a hydrophobic guiding layer nested around the motor shaft 110 from the inside to the outside.

[0037] The magnetic fluid sealing layer 200 includes an annular permanent magnet 210, a gradient magnetic field gap 220 located between the motor shaft 110 and the end cover 120 of the motor 100, and magnetic fluid filling the gap. The annular permanent magnet 210 is embedded in the inner wall of the end cover 120 of the motor 100, and the inner circumferential surface of the annular permanent magnet 210 forms a radial clearance fit with the motor shaft 110.

[0038] The dynamic lip seal layer 300 includes a main lip 310 that is interference-fitted with the motor shaft 110, a secondary lip 320 that contacts the end cap 120, and a wave spring 330 that abuts against the back of the main lip 310.

[0039] The dustproof layer 400 is located at the opening on the outside of the end cover 120 of the motor 100. The dustproof layer 400 includes a three-level detour channel 410 with decreasing height and an oblique air guide hole 420 that penetrates the end cover 120 of the motor 100. The entrance of the detour channel 410 is directly facing the rotation direction of the wheel hub of the electric bicycle.

[0040] The hydrophobic guide layer covers the outer surface of the end cap 120 of the motor 100. The hydrophobic guide layer includes a plurality of V-shaped grooves 520 and at least one guide vane 510, the end of which extends into the hub spoke mounting groove of the electric bicycle.

[0041] In some embodiments, the magnetohydrodynamic sealing layer 200, dynamic lip sealing layer 300, dustproof layer 400, and hydrophobic guiding layer are sequentially stacked along the axial direction of the motor shaft 110, with a total thickness ≤18mm. The axial distance between the magnetohydrodynamic sealing layer 200 and the dynamic lip sealing layer 300 is 3-5mm, and the end of the guide vane 510 is ≤2mm from the edge of the hub spoke mounting groove.

[0042] By setting the axial distance between the magnetohydrodynamic sealing layer 200 and the dynamic lip sealing layer 300 to 3-5 mm, and the distance from the end of the guide vane 510 to the edge of the hub spoke mounting groove to ≤2 mm, the sealing structure is constrained within a limited space.

[0043] In some embodiments, the axial width of the gradient magnetic field gap 220 is 0.15-0.25mm, the permanent magnet is an N50-N52 grade neodymium iron boron magnet, the distance between two adjacent magnetic poles is ≤2mm, and the magnetic field strength gradient between two adjacent magnetic poles is ≥400T / m.

[0044] In some embodiments, the magnetic fluid has a saturation magnetization of 450-G and a viscosity of 280-320 mPa·s.

[0045] By combining a gradient magnetic field with a high-viscosity magnetic fluid, axial migration of the magnetic fluid under centrifugal force is prevented, ensuring that the leakage rate is <0.1mL / 100h when the rotation speed is ≤3000rpm.

[0046] In some embodiments, the interference fit between the main lip 310 and the motor shaft 110 is 0.25-0.35 mm, the lip tip angle is 55°-65°, and the contact width with the motor shaft 110 is 0.2-0.3 mm; the initial compression of the wave spring 330 is 12%-18%, and the spring wire diameter is 0.5-0.7 mm.

[0047] Through the interference fit between the main lip 310 and the motor shaft 110, and the synergistic effect of the preload of the wave spring 330, the lip contact pressure of the main lip 310 is stabilized at 0.7-0.9MPa, compensating for the risk of seal failure when the radial runout of the shaft is ±0.4mm.

[0048] In some embodiments, the height junction of the detour channel 410 is connected by a 120° bend.

[0049] In some embodiments, the inner wall surface roughness Ra of the meandering channel 410 is ≤0.15μm.

[0050] By setting the height intersection of the detour channel 410 to a 120° bend angle connection, the low roughness of the inner wall surface of the detour channel 410 is combined with the low roughness to reduce the particle adhesion rate and improve the interception efficiency of PM10 and above dust.

[0051] In some embodiments, the air guide vanes 510 are arranged in a spiral at an angle of 12°-15°, and the spacing between adjacent air guide vanes 510 is 1 / 6-1 / 8 of the hub circumference.

[0052] In some embodiments, the V-groove 520 has a depth of 40-60 μm and a width of 150-250 μm, and a fluorosilane coating is applied to the surface of the V-groove 520.

[0053] By using the guide vanes 510 arranged in a spiral at an angle of 12°-15°, and the guide vanes 510 and the hub rotation to generate a synergistic airflow effect, the amount of residual water film on the surface is reduced. The surface of the V-groove 520 structure is coated with a fluorosilane coating to improve hydrophobic durability.

[0054] The waterproof and dustproof sealing assembly for the rear wheel motor of the electric bicycle provided in this embodiment, compared with the prior art, achieves multi-level coordinated sealing within the limited axial space of the motor shaft 110 of the motor 100 by using a magnetic fluid sealing layer 200, a dynamic lip sealing layer 300, a dustproof layer 400, and a hydrophobic guiding layer nested around the motor shaft 110 from the inside out. Compared with the single-layer rubber ring sealing structure in the prior art, the multi-layer sealing structure of this application can still maintain the dustproof and waterproof sealing of the motor 100 even if one or two layers of the sealing structure fail, thereby improving the sealing effect of the motor 100.

[0055] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes to this utility model should also fall within the protection scope of the claims of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. A waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle, characterized in that, It includes a magnetic fluid sealing layer (200), a dynamic lip sealing layer (300), a dustproof layer (400), and a hydrophobic guiding layer, which are nested around the motor shaft (110) from the inside out; The magnetic fluid sealing layer (200) includes an annular permanent magnet (210), a gradient magnetic field gap (220) located between the motor shaft (110) and the end cap (120) of the motor (100), and magnetic fluid filling the gap. The annular permanent magnet (210) is embedded in the inner wall of the end cap (120) of the motor (100), and the inner circumferential surface of the annular permanent magnet (210) forms a radial clearance fit with the motor shaft (110). The dynamic lip seal layer (300) includes a main lip (310) that is interference-fitted with the motor shaft (110), a secondary lip (320) that contacts the end cap (120), and a wave spring (330) that abuts against the back of the main lip (310); The dustproof layer (400) is located at the opening on the outside of the end cover (120) of the motor (100). The dustproof layer (400) includes a three-level detour channel (410) with decreasing height and an oblique air guide hole (420) that penetrates the end cover (120) of the motor (100). The entrance of the detour channel (410) is directly opposite to the rotation direction of the wheel hub of the electric bicycle. The hydrophobic guide layer covers the outer surface of the end cap (120) of the motor (100). The hydrophobic guide layer includes a plurality of V-shaped grooves (520) and at least one guide vane (510), the end of which extends into the hub spoke mounting groove of the electric bicycle.

2. The waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle as described in claim 1, characterized in that, The magnetic fluid sealing layer (200), dynamic lip sealing layer (300), dustproof layer (400), and hydrophobic guide layer are arranged in sequence along the axial direction of the motor shaft (110), with a total thickness of ≤18mm. The axial distance between the magnetic fluid sealing layer (200) and the dynamic lip sealing layer (300) is 3-5mm. The end of the guide vane (510) is ≤2mm from the edge of the hub spoke mounting groove.

3. The waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle as described in claim 1 or 2, characterized in that, The axial width of the gradient magnetic field gap (220) is 0.15-0.25mm, the permanent magnet is a N50-N52 grade neodymium iron boron magnet, the distance between two adjacent magnetic poles is ≤2mm, and the magnetic field strength gradient between two adjacent magnetic poles is ≥400T / m.

4. The waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle as described in claim 3, characterized in that, The magnetic fluid has a saturation magnetization of 450-G and a viscosity of 280-320 mPa·s.

5. The waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle as described in claim 1 or 2, characterized in that, The interference fit between the main lip (310) and the motor shaft (110) is 0.25-0.35 mm, the lip tip angle is 55°-65°, and the contact width with the motor shaft (110) is 0.2-0.3 mm; the initial compression of the wave spring (330) is 12%-18%, and the spring wire diameter is 0.5-0.7 mm.

6. The waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle as described in claim 1 or 2, characterized in that, The height junction of the detour channel (410) is connected by a 120° bend.

7. The waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle as described in claim 6, characterized in that, The inner wall surface roughness Ra of the meandering channel (410) is ≤0.15μm.

8. The waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle as described in claim 1 or 2, characterized in that, The guide vanes (510) are arranged in a spiral at an angle of 12°-15°, and the spacing between adjacent guide vanes (510) is 1 / 6-1 / 8 of the hub circumference.

9. The waterproof and dustproof sealing assembly for the rear wheel motor of an electric bicycle as described in claim 8, characterized in that, The V-shaped groove (520) has a depth of 40-60μm and a width of 150-250μm, and a fluorosilane coating is applied to the surface of the V-shaped groove (520).

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