Water-cooled hub motor for electric bicycle

Abstract

The utility model discloses a water-cooled hub motor for an electric bicycle. The water-cooled hub motor comprises a stator and an outer rotor, the stator comprises a left half shaft and a right half shaft, an outer cavity with a circular section is integrally formed between the left half shaft and the right half shaft, two water pipe channels are arranged in the right half shaft in the axial direction of the right half shaft, the stator further comprises an inner cavity matched with the outer cavity, and a water inlet pipe and a water outlet pipe are arranged on the inner cavity. The inner cavity is arranged in the outer cavity, and the tail ends of the water inlet pipe and the water outlet pipe extend to the outside of the right half shaft after the water inlet pipe and the water outlet pipe respectively penetrate through one water pipe channel; the outer side of the outer cavity is coated with an iron core in the circumferential direction, and the iron core is used for arranging a winding; the outer rotor comprises a left end cover, a right end cover and a hub; and a plurality of magnetic steels are uniformly distributed on the inner side wall of the hub along the circumferential direction. The hub motor can dissipate heat of the core part of the hub motor, and is beneficial to improving the work efficiency of an electric vehicle and prolonging the service life of the electric vehicle.

Description

Technical Field

[0001] The utility model relates to an electric bicycle, in particular to an electric bicycle power assembly. Background Art

[0002] Electric bicycles include two-wheeled, three-wheeled or four-wheeled vehicles, usually referring to two-wheeled vehicles. In the prior art, the core power component of electric bicycles is the hub motor. The advantage of the hub motor is that the power device, transmission device and braking device are all integrated into the wheel hub, thereby greatly simplifying the mechanical part of the vehicle. During the operation of the hub motor, its windings and core will generate heat due to eddy current loss. When the motor works for a long time or is overloaded, it will not be able to dissipate heat quickly, causing adverse consequences such as accelerated aging of components, demagnetization of permanent magnets, and decreased power performance. Therefore, the rapid heat dissipation technology of the hub motor has always been a research topic in the industry.

[0003] In the existing technology, wheel hub motors mainly use air cooling to dissipate heat. Some manufacturers have developed oil cooling technology. The principle is to inject a small amount of cooling oil as a heat dissipation medium into the wheel hub. The cooling oil is deposited on the lower part of the wheel hub by its own weight. The stator is partially immersed in the cooling oil. During the rotation of the outer rotor, its inner cavity is in contact with the cooling oil. When the motor temperature rises, the cooling oil is used to accelerate the heat dissipation. Its disadvantages are: high requirements for the sealing of the outer rotor, aging of the seal after long-term use, and potential failure of oil leakage, which not only affects the performance of the vehicle, but also causes oil stains on the surface of the wheel hub, and poor user experience; in addition, the cooling oil is likely to age and wear out, and professional maintenance and regular inspections are required, which increases the manufacturer's after-sales costs. Summary of the invention

[0004] The technical problem to be solved by the utility model is to provide a water-cooled hub motor for an electric bicycle, which can dissipate heat from the core part of the hub motor, thereby improving the work efficiency of the electric bicycle and extending its service life.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0006] A water-cooled hub motor for an electric bicycle comprises a stator and an outer rotor; the stator comprises a left half shaft and a right half shaft, an outer cavity with a circular cross section is formed integrally between the left half shaft and the right half shaft, two water pipe channels are arranged in the right half shaft along its axial direction, and an inner cavity matching the outer cavity is also included, a water inlet pipe and a water outlet pipe are arranged on the inner cavity, the inner cavity is arranged inside the outer cavity, the starting ends of the water inlet pipe and the water outlet pipe are arranged in the inner cavity, the water inlet pipe and the water outlet pipe respectively pass through a water pipe channel, and the ends thereof extend to the outside of the right half shaft; the outer side of the outer cavity is circumferentially covered with an iron core for arranging a winding;

[0007] The outer rotor includes a left end cover, a right end cover, and a wheel hub. The left end cover is movably connected to the left half shaft through a left end bearing, and the right end cover is movably connected to the right half shaft through a right end bearing. The wheel hub is fixedly connected to the left end cover and the right end cover, and a plurality of magnetic steels are evenly distributed on the inner side wall of the wheel hub along the circumferential direction.

[0008] Preferably, the starting end of the water inlet pipe is bent downward in the inner cavity, and the pipe opening thereof is arranged below the horizontal axis of the inner cavity.

[0009] Preferably, the starting end of the water outlet pipe is bent upward in the inner cavity, and the pipe mouth is arranged above the horizontal axis of the inner cavity.

[0010] Preferably, it also includes a water tank and a circulation pump, and the inner cavity forms a closed pipeline with the water tank through the water inlet pipe, the water outlet pipe, the circulation pump and the water tank.

[0011] Preferably, it also includes a water tank arranged on the electric vehicle and higher than the inner cavity, the inner cavity is connected to the water tank via a water inlet pipe, the free end of the water outlet pipe extends beyond the right half axis and then bends downward, and the free end of the water outlet pipe is also connected in series with a one-way valve, and the high-temperature water vapor in the inner cavity is discharged through the one-way valve.

[0012] The technical effects of the utility model are embodied in the following aspects: ① The inner cavity is arranged inside the wheel hub motor, and water is led out for circulation through the water inlet pipe and the water outlet pipe. When working, the heat generated by the wheel hub motor core can be led out and released through the medium, and the heat dissipation effect is ideal. ② The inner cavity is completely in contact with the iron core in the circumferential direction through the outer cavity to achieve heat dissipation, and the contact area is large, which further ensures the heat dissipation effect. ③ The inner cavity and the outer cavity form a secondary seal, and the circulating water will not directly contact the iron core, magnetic steel, winding and other metal parts, so as to achieve the purpose of insulation. The inner cavity and the outer cavity directly use metal one-piece molded parts, and the outer rotor as a moving part has no sealing requirements, so that the motor does not need to use glue, sealing rings and other easily consumable seals, which greatly reduces potential faults. ④ Using circulating water as the medium, the heat dissipation effect is good, and no pollution is generated by drainage or exhaust steam. It is environmentally friendly, the vehicle appearance is clean and tidy, the user experience is good, and it is conducive to market promotion. Due to the improved heat dissipation efficiency, the purpose of reducing the temperature rise of the motor and delaying the aging of components is achieved, which is conducive to improving the work efficiency of the wheel hub motor and extending the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the assembly state of the utility model;

[0014] Figure 2 It is an exploded view of the utility model;

[0015] Figure 3 It is a cross-sectional view of the stator and outer rotor in the utility model in the matching state. DETAILED DESCRIPTION

[0016] Embodiment 1

[0017] like Figure 1 , Figure 2 , Figure 3 It can be seen that the present embodiment includes a rear frame 1, a stator 2 and an outer rotor 3. The stator 2 is fixedly connected to the rear frame 1, and the outer rotor 3 matches the stator 2.

[0018] The stator 2 includes a left half shaft 20 and a right half shaft 21, an outer cavity 22 with a circular cross section is formed between the left half shaft 20 and the right half shaft 21, two water pipe channels 210 are arranged in the right half shaft 21 along its axial direction, and an inner cavity 4 matching the outer cavity 22 is also included, and the inner cavity 4 is provided with a water inlet pipe 40 and a water outlet pipe 41, and the inner cavity 4 is arranged inside the outer cavity 22, and the water inlet pipe 40 and the water outlet pipe 41 respectively pass through a water pipe channel 210, and the ends thereof extend to the outside of the right half shaft 21; the inner cavity 4 is connected to the water tank arranged on the electric bicycle through the water inlet pipe 40. The outer side of the outer cavity 22 is circumferentially covered with an iron core 25 for arranging windings.

[0019] The outer rotor 3 includes a left end cover 30, a right end cover 31, and a wheel hub 32. The left end cover 30 is movably connected to the left half shaft 20 through a left end bearing 23, and the right end cover 31 is movably connected to the right half shaft 21 through a right end bearing 24. The wheel hub 32 is fixedly connected to the left end cover 30 and the right end cover 31, and a plurality of magnets 33 are evenly distributed on the inner side wall of the wheel hub 32 along the circumferential direction.

[0020] The shaft ends of the left half shaft 20 and the right half shaft 21 are both provided with positioning pieces for fixed connection with the vehicle frame.

[0021] The processing of the stator 2 is as follows: first, the inner cavity 4 is manufactured, and the water inlet pipe 40 and the water outlet pipe 41 are welded and formed; the starting ends of the water inlet pipe 40 and the water outlet pipe 41 are both set in the inner cavity 4. The obtained inner cavity 4 is fixed to the mold, and the molten metal liquid is injected. After cooling, the blank is taken out and finely processed to obtain the inner cavity 4, the left half shaft 20, the right half shaft 21, and the outer cavity 22 assembly, and the stator is finely processed. The inner cavity 4 is cast and arranged in the outer cavity 22 in an integral manner, and the two are in seamless contact, and the heat conduction efficiency is high.

[0022] Assembly steps:

[0023] A. The magnetic steel 33 is assembled on the wheel hub 32 for standby use;

[0024] B. The left end cover 30 is connected to the left half shaft 20 via the left end bearing 23, and the right end cover 31 is connected to the right half shaft 21 via the right end bearing 24. The workpiece obtained in step A is mounted on the workpiece obtained in step B.

[0025] C. The left half shaft 20 and the right half shaft 21 are respectively connected to the rear frame 1 on both sides, and the water inlet pipe 40 and the water outlet pipe 41 are extended beyond the shaft ends and then connected to the water circulation device.

[0026] The starting end of the water inlet pipe 40 is bent downward in the inner cavity 4, and its pipe opening is arranged below the horizontal axis of the inner cavity 4; the starting end of the water outlet pipe 41 is bent upward in the inner cavity 4, and its pipe opening is arranged above the horizontal axis of the inner cavity 4. With this structure, when the inner cavity 4 is connected to the external water tank, the forced circulating water enters from the lower end of the inner cavity 4 and is discharged from the upper end, which is conducive to improving the cooling effect.

[0027] The technical effects of this embodiment are embodied in:

[0028] ① The inner cavity 4 is arranged inside the wheel hub motor, and water is led out for circulation through the water inlet pipe 40 and the water outlet pipe 41. When working, the heat generated by the inner core of the wheel hub motor can be led out and released through the medium, and the heat dissipation effect is ideal.

[0029] ② The inner cavity 4 is in full contact with the iron core 25 in the circumferential direction through the outer cavity 22 to achieve heat dissipation, and the contact area is large, further ensuring the heat dissipation effect.

[0030] ③ The inner cavity 4 and the outer cavity 22 perform secondary sealing on the circulating water, and the core parts such as the iron core, magnetic steel, windings, etc. are completely isolated to achieve the purpose of insulation and help to extend the service life.

[0031] ④ Using circulating water as the medium, the heat dissipation effect is good, no pollution is generated by drainage or exhaust, it is environmentally friendly, the vehicle appearance is clean and tidy, the user experience is good, and it is conducive to market promotion.

[0032] In this embodiment, a water tank and a circulation pump are provided on the frame of the electric bicycle. The inner cavity 4 forms a closed pipeline through the water inlet pipe 40, the water outlet pipe 41, the circulation pump and the water tank, and the cooling water is circulated. The circulation pipeline including the right half shaft 21 has a large air contact surface and a good heat dissipation effect. If necessary, a heat sink can be added to the circulation pipeline.

[0033] Embodiment 2

[0034] In this embodiment, a water tank is provided on the frame of the electric bicycle above the inner cavity 4. The inner cavity 4 is connected to the water tank via a water inlet pipe 40. The water outlet pipe 41 in the inner cavity 4 is bent upward at its starting end, and its starting end is arranged above the horizontal axis of the inner cavity 4. The terminal of the water outlet pipe 41 extends to the outside of the right half shaft 21 and then bends downward. The free end of the water outlet pipe 41 outside the right half shaft 21 is also connected in series with a one-way valve, and the high-temperature water vapor in the inner cavity 4 is discharged through the one-way valve. The circulation device is omitted in this embodiment, and cooling water is used as a consumable. Since the water tank is higher than the inner cavity 4, cooling water can enter by its own weight. Since the outlet pipe 41 is arranged above the horizontal axis of the inner cavity 4, the steam discharged is mainly the steam generated by the heating of the motor. When the hub motor is not working or working at a low temperature, basically no steam is discharged, so that the water consumption per unit mileage is controlled.

[0035] The specific implementation methods of the present invention include but are not limited to the above-mentioned embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field can make various corresponding changes and deformations according to the present invention, but still fall within the protection scope of the present invention.

Claims

1. A water-cooled hub motor for an electric bicycle, comprising a stator (2) and an outer rotor (3); characterized in that: The stator (2) comprises a left half shaft (20) and a right half shaft (21); an outer cavity (22) with a circular cross section is integrally formed between the left half shaft (20) and the right half shaft (21); two water pipe channels (210) are arranged in the right half shaft (21) along its axial direction; and an inner cavity (4) matching the outer cavity (22); a water inlet pipe (40) and a water outlet pipe (41) are arranged on the inner cavity (4); the inner cavity (4) is arranged inside the outer cavity (22); the starting ends of the water inlet pipe (40) and the water outlet pipe (41) are arranged in the inner cavity (4); the water inlet pipe (40) and the water outlet pipe (41) respectively pass through a water pipe channel (210), and the ends thereof extend to the outside of the right half shaft (21); the outer side of the outer cavity (22) is circumferentially covered with an iron core (25) for arranging a winding; The outer rotor (3) comprises a left end cover (30), a right end cover (31), and a wheel hub (32); the left end cover (30) is movably connected to the left half shaft (20) via a left end bearing (23); the right end cover (31) is movably connected to the right half shaft (21) via a right end bearing (24); the wheel hub (32) is fixedly connected to the left end cover (30) and the right end cover (31); and a plurality of magnetic steels (33) are evenly distributed on the inner side wall of the wheel hub (32) along the circumferential direction.

2. The water-cooled hub motor for an electric bicycle according to claim 1, characterized in that: The starting end of the water inlet pipe (40) is bent downward in the inner cavity (4), and the pipe opening is arranged below the horizontal axis of the inner cavity (4).

3. The water-cooled hub motor for an electric bicycle according to claim 1, characterized in that: The starting end of the water outlet pipe (41) is bent upward in the inner cavity (4), and the pipe opening is arranged above the horizontal axis of the inner cavity (4).

4. The water-cooled hub motor for an electric bicycle according to claim 1, characterized in that: It also includes a water tank and a circulation pump. The inner cavity (4) forms a closed pipeline through a water inlet pipe (40), a water outlet pipe (41), the circulation pump and the water tank.

5. The water-cooled hub motor for an electric bicycle according to claim 1, characterized in that: It also includes a water tank arranged on the electric vehicle and higher than the inner cavity (4); the inner cavity (4) is connected to the water tank via a water inlet pipe (40); the free end of the water outlet pipe (41) extends beyond the right half shaft (21) and then bends downward; the free end of the water outlet pipe (41) is also connected in series with a one-way valve.

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