Small lightweight hub motor

Abstract

The utility model discloses a small-sized lightweight wheel hub motor, which relates to the technical field of electric bicycles and comprises a wheel hub shell, a central spindle penetrating through two ends of the wheel hub shell, a planetary gear assembly and a motor assembly are arranged in the wheel hub shell, the planetary gear assembly and the motor assembly are mounted on the central spindle, and the planetary gear assembly and the motor assembly are separated by a baffle. And the baffle plate is fixed in the hub shell. According to the utility model, the baffle plate is additionally arranged between the planetary gear assembly and the motor assembly, so that grease, iron pins and powder residues in the planetary gear assembly can be prevented from leaking to one side of the motor assembly, and the phenomenon that the generator assembly is burnt down can be effectively prevented; the arrangement of the baffle plate can reasonably utilize the space to design the size structures of the clutch (one-way bearing) and the planetary gear assembly, so that the torsion and the power are larger, the noise can be reduced, the service life is longer, and finally the purposes of prolonging the service life of the hub motor and enabling the motor to be larger in force and more stable are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric bicycles, in particular to a small lightweight hub motor and a hub. Background Art

[0002] At present, there are two types of electric bicycle hub motors: direct drive motors and reduction motors. In order to ensure the driving torque required for riding, the direct drive motor must increase the motor size to meet the torque requirements. Therefore, direct drive motors are generally bulky and cannot meet the market demand for miniaturization and lightweight. In order to meet market demand, manufacturers have launched a reduction hub motor with an internal planetary reduction structure, which greatly reduces the overall size of the motor. The direct drive hub motor has been reduced from a diameter of φ160-200mm to φ100-120mm. As mentioned above, although there has been considerable progress, consumers' demand for miniaturization and lightweighting has also increased, requiring smaller hub motors.

[0003] Chinese patent application number CN201710421973.6 discloses a micro-wheel hub motor suitable for electric bicycles. Compared with the prior art, the micro-wheel hub motor suitable for electric bicycles achieves a motor outer diameter of φ65-70mm by improving the shape of planetary gears and related structures while meeting the output power and gear meshing strength standards of electric bicycles, filling the gap in the miniaturization of micro-motors in the field of electric bicycles in the world. On the basis of the original patent application, the plug-in spindle is changed to an integral spindle, which increases the strength of the micro-wheel hub motor and reduces the noise. However, the micro-electric bicycle hub motor still has the problem that grease, iron pins and powder residue in the planetary gear assembly are easy to leak into the motor assembly, causing damage to the motor assembly. Therefore, a small and lightweight wheel hub motor and wheel hub are proposed. Utility Model Content

[0004] Technical issues solved

[0005] The purpose of the utility model is to make up for the deficiencies of the prior art and to provide a small and lightweight hub motor and a hub.

[0006] Technical Solution

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a small and lightweight wheel hub motor, comprising a wheel hub shell, wherein a core shaft penetrating through both ends of the wheel hub shell and a planetary gear assembly and a motor assembly mounted on the core shaft are arranged in the wheel hub shell, wherein the planetary gear assembly and the motor assembly are separated by a baffle, wherein the baffle is fixed inside the wheel hub shell, and a baffle is installed between the planetary gear assembly and the motor assembly, so as to prevent grease, iron pins and powder residue in the planetary gear assembly from leaking to the motor assembly, thereby effectively preventing the phenomenon of burning of the motor assembly; the provision of the baffle can also reasonably utilize space to design the size structure of the clutch (one-way bearing) and the planetary gear assembly, so as to increase the torque and power, reduce noise and extend its service life, and finally achieve the purpose of increasing the service life of the wheel hub motor and making the motor more powerful and stable.

[0008] It also includes hollow spokes, which are installed on the wheel hub shell, and the interior of the hollow spokes is provided with a wire, and the connection between the hollow spokes and the wheel hub shell is provided with a first waterproof structure, the first waterproof structure includes a threaded column provided on the wheel hub shell, a nylon ferrule sleeved on the threaded column, and a nut pressed against the upper end of the nylon ferrule and threadedly connected to the threaded column, the threaded column and the nut are provided with a through hole for the installation of the hollow spoke, the diameter of the through hole is equivalent to the diameter of the hollow spoke, and the end of the hollow spoke away from the first waterproof structure is provided with a second waterproof structure; the second waterproof structure includes a second threaded A column, a rubber sealing ring sleeved on the second threaded column, a second nut pressed against one end of the rubber sealing ring and threadedly connected to the second threaded column, a second nylon ferrule pressed against one end of the second threaded column, and a clamping nut pressed against one end of the second nylon ferrule and threadedly connected to the second threaded column. The first waterproof structure is installed at the connection between the wheel hub shell and the hollow spoke, which can effectively improve the waterproof effect of the hollow spoke when the hollow spoke is installed. The second waterproof structure is installed at the connection between the hollow spoke and the rim, which can effectively improve the waterproof effect of the connection between the hollow spoke and the rim. The two waterproof structures ensure the waterproof effect of the device and avoid water seepage.

[0009] A pressure relief nozzle is also provided on the side of the hub shell opposite to the first waterproof structure, through which the high-pressure gas and heat generated by the high-speed rotation of the hub motor can be effectively discharged, preventing the high pressure and high heat in the hub motor from damaging the motor.

[0010] Preferably, the motor assembly comprises an iron core group fixedly connected to the hub shell, a rotatable rotor group is arranged in the middle of the iron core group, and the rotor group is mounted on the core shaft through a bearing.

[0011] Preferably, the planetary gear assembly includes a sun gear, which is connected to the rotor group through a flange, and a plurality of planetary gears are meshed on the outer side of the sun gear. The plurality of planetary gears are mounted on a planetary bracket, and the planetary bracket is fixedly connected to the core shaft, and a plurality of planetary gears are meshed on the outer side with an outer ring gear, and the outer ring gear is connected to the hub shell through a one-way bearing transmission.

[0012] Preferably, the wheel hub shell is composed of a wheel hub A shell and a wheel hub B shell, the wheel hub A shell and the wheel hub B shell are connected by hub bolts, and a stepped groove for installing a baffle is provided in the wheel hub A shell.

[0013] A small lightweight hub motor also includes a wheel rim fixedly connected to one end of a plurality of hollow spokes, a battery pack is arranged in an annular array inside the wheel rim, the battery pack is connected to a wire, and the end of the wire away from the battery pack is electrically connected to a motor assembly of the hub motor.

[0014] Preferably, a through hole for installing the second threaded column is provided on the rim.

[0015] Beneficial effects:

[0016] Compared with the prior art, the small and lightweight hub motor and hub have the following beneficial effects:

[0017] 1. The utility model installs a baffle between the planetary gear assembly and the motor assembly, which can prevent grease, iron pins and powder residue in the planetary gear assembly from leaking to the motor assembly, thereby effectively preventing the motor assembly from burning;

[0018] Second, the baffle can also reasonably utilize the space to design the size structure of the clutch (one-way bearing) and the planetary gear assembly, increase the torque and power, reduce noise, and extend the service life, ultimately achieving the purpose of increasing the service life of the hub motor and making the motor more powerful and stable;

[0019] 3. The first waterproof structure is installed at the connection between the hub shell and the hollow spoke, which can effectively improve the waterproof effect when the hollow spoke is installed. The second waterproof structure is installed at the connection between the hollow spoke and the rim, which can effectively improve the waterproof effect of the connection between the hollow spoke and the rim. The two waterproof structures ensure the waterproof effect of the device and avoid water seepage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the utility model;

[0021] Figure 2 For the utility model Figure 1 A schematic diagram of the structure enlarged at B in the middle;

[0022] Figure 3 This is a schematic diagram of the structure of the hub motor of the utility model;

[0023] Figure 4 It is a cross-sectional structural schematic diagram of the hub motor of the utility model;

[0024] Figure 5 For this utility model Figure 4 A schematic diagram of the structure enlargement at the center A;

[0025] Figure 6 It is an enlarged schematic diagram of the structure of the first waterproof structure of the utility model.

[0026] In the figure:

[0027] 1. Hub shell; 101. Hub A shell; 102. Hub B shell; 103. Hub bolt; 104. Step groove; 2. Mandrel; 4. Wire; 5. Baffle; 6. Hollow spoke; 7. First waterproof structure; 701. Threaded column; 702. Nylon ferrule; 703. Nut; 8. Second waterproof structure; 801. Second threaded column; 802. Rubber sealing ring; 803. Second nut; 804. Second nylon ferrule; 805. Compression nut; 9. Core group; 10. Rotor group; 11. Bearing; 12. Sun gear; 13. Flange; 14. Planetary gear; 15. Planetary bracket; 16. Outer gear ring; 17. One-way bearing; 18. Pressure relief nozzle; 19. Rim; 20. Battery pack. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] See also Figure 1 to Figure 6As shown, the utility model provides a technical solution: a small and lightweight wheel hub motor, including a wheel hub shell 1, the wheel hub shell 1 is composed of a wheel hub A shell 101 and a wheel hub B shell 102, the wheel hub A shell 101 and the wheel hub B shell 102 are connected by a wheel hub bolt 103, the wheel hub A shell 101 is provided with a stepped groove 104 for installing a baffle 5, the wheel hub shell 1 is provided with a spindle 2 passing through both ends of the wheel hub shell 1 and a planetary gear assembly and a motor assembly installed on the spindle 2, the planetary gear assembly and the motor assembly are separated by a baffle 5, and the baffle 5 is fixed inside the wheel hub shell 1. A baffle 5 is installed between the components. The baffle 5 is made of stainless steel and can prevent grease, iron pins and powder residue in the planetary gear assembly from leaking to the motor assembly, thereby effectively preventing the motor assembly from burning. The baffle 5 can also reasonably utilize space to design the clutch (one-way bearing 17) and the size structure of the planetary gear assembly, increase the torque and power, enhance the fixing effect of the planetary gear and the clutch, and keep the clutch and the planetary gear balanced, stable, and uniform in force, and can reduce noise and extend its service life, ultimately achieving the purpose of increasing the service life of the hub motor and making the motor stronger and more stable.

[0030] A baffle installation process for a small and lightweight hub motor is as follows:

[0031] Step 1: Use liquid nitrogen to lower the temperature of the stainless steel baffle 5 to -180°C to -30°C, at which time the axial diameter of the baffle 5 shrinks by 0.4mm to 0.5mm;

[0032] Step 2: Install the baffle 5 with the shrunk shaft diameter into the hub A shell 101 at room temperature, and the baffle 5 is blocked by the stepped groove 104 so that the baffle 5 is fixed at the position of the stepped groove 104;

[0033] Step 3: Under room temperature, wait for the baffle 5 to recover in temperature and restore its size to its original size, completing the interference fit with the wheel hub A shell 101;

[0034] Step 4: Apply glue to the edge where the baffle 5 and the hub A shell 101 contact each other to seal.

[0035] The baffle 5 is installed by the cold installation method and sealed with glue. Compared with the traditional welding fixing method, the baffle 5 can be easily disassembled and repaired after being damaged during long-term use of the equipment without affecting the installation effect.

[0036] like Figure 6As shown, the hub motor of the device also includes a hollow spoke 6, a wire 4 is passed through the interior of the hollow spoke 6, the hollow spoke 6 is installed on the wheel hub shell 1, and a first waterproof structure 7 is provided at the connection between the hollow spoke 6 and the wheel hub shell 1, the first waterproof structure 7 includes a threaded column 701 provided on the wheel hub shell 1, a nylon ferrule 702 sleeved on the threaded column 701, and a nut 703 pressed against the upper end of the nylon ferrule 702 and threadedly connected to the threaded column 701, the nut 703 presses the nylon ferrule 702 and is locked on the threaded column 701, a through hole for installing the hollow spoke 6 is opened in the threaded column 701 and the nut 703, the diameter of the through hole is equivalent to the diameter of the hollow spoke 6, the first waterproof structure is installed at the connection between the wheel hub shell 1 and the hollow spoke 6, and can effectively improve the waterproof effect of the hollow spoke 6 when it is installed.

[0037] The device also includes a pressure relief nozzle 18 installed on one side of the wheel hub shell 1. The function of the pressure relief nozzle 18 is to exhaust air and cool down to prevent high pressure and high heat in the wheel hub motor.

[0038] like Figure 2 As shown, a second waterproof structure 8 is provided at one end of the hollow spoke 6 away from the first waterproof structure 7; the second waterproof structure 8 includes a second threaded column 801, a rubber sealing ring 802 sleeved on the second threaded column 801, a second nut 803 pressed against one end of the rubber sealing ring 802 and threadedly connected to the second threaded column 801, the second nut 803 presses the rubber sealing ring 802 and is locked on the second threaded column 801, a second nylon ring 804 pressed against one end of the second threaded column 801, and a clamping nut 805 pressed against one end of the second nylon ring 804 and threadedly connected to the second threaded column 801, the clamping nut 805 presses the second nylon ring 804 and is locked on the second threaded column 801, the second waterproof structure is installed at the connection between the hollow spoke 6 and the rim 19, which can effectively improve the waterproof effect of the connection between the hollow spoke 6 and the rim 19, and the two waterproof structures ensure the waterproof effect of the device and avoid water seepage.

[0039] Please pay attention to Figure 4 The motor assembly includes an iron core group 9 which is relatively fixedly connected to the wheel hub shell 1. A rotatable rotor group 10 is arranged in the middle of the iron core group 9. The rotor group 10 is installed on the core shaft through a bearing 11. The planetary gear assembly includes a sun gear 12. The sun gear 12 is connected to the rotor group 10 through a flange 13. A plurality of planetary gears 14 are meshed on the outer side of the sun gear 12. The plurality of planetary gears 14 are mounted on a planetary bracket 15. The planetary bracket 15 is fixedly connected to the core shaft 2. An outer ring gear 16 is meshed on the outer side of the plurality of planetary gears 14. The outer ring gear 16 is connected to the wheel hub shell 1 through a one-way bearing 17.

[0040] A wheel hub of a small and lightweight hub motor, the wheel hub also includes a rim 19, a battery pack 20 is arranged in an annular array inside the rim 19, the battery pack 20 is connected to a wire 4, and the end of the wire 4 away from the battery pack 20 is electrically connected to the motor assembly of the hub motor, and a through hole for installing a second threaded column 801 is opened on the rim 19, and the second threaded column 801 of the second waterproof structure 8 is installed in the through hole.

[0041] The working principle of the small and lightweight hub motor is as follows: a battery pack 20 arranged in a ring array is arranged in the rim 19, and the battery pack 20 provides electrical energy to the motor assembly through the wire 4 (located in the hollow spoke 6). After the motor assembly is energized, the rotor group 10 rotates (set to the positive direction), and the rotor group 10 drives the sun gear 12 to rotate in the positive direction. The sun gear 12 drives the outer ring gear 16 to rotate in the opposite direction through the three planetary gears 14, and the outer ring gear 16 drives the hub shell 1 to rotate through the clutch (one-way bearing 17), so that the entire wheel rotates and starts to move. When the outer ring gear 16 moves in the opposite direction to the above-mentioned direction, due to the action of the clutch (separation), the outer ring gear 16 cannot drive the hub shell 1, so that the planetary gear assembly can only transmit in one direction. This hub motor is suitable for installation on a bicycle. After use, the entire vehicle looks like a non-powered bicycle on the outside, but it is actually an electric motorcycle. The battery pack 20 is evenly built into the rim 19, and the overall product appears to be lighter and simpler, without a sense of bulkiness.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A small and lightweight hub motor, comprising a hub shell (1), characterized in that: The wheel hub shell (1) is provided with a core shaft (2) penetrating through both ends of the wheel hub shell (1), and a planetary gear assembly and a motor assembly mounted on the core shaft (2); the planetary gear assembly and the motor assembly are separated by a baffle (5), and the baffle (5) is fixed inside the wheel hub shell (1); The wheel hub also comprises a hollow spoke (6), wherein the hollow spoke (6) is mounted on the wheel hub shell (1), a wire (4) is passed through the interior of the hollow spoke (6), a first waterproof structure (7) is provided at the connection between the hollow spoke (6) and the wheel hub shell (1), the first waterproof structure (7) comprising a threaded column (701) arranged on the wheel hub shell (1), a nylon ferrule (702) sleeved on the threaded column (701), and a nut (703) pressed against the upper end of the nylon ferrule (702) and threadedly connected to the threaded column (701), the threaded column (701) and the nut (703) are provided with a through hole for mounting the hollow spoke (6), and the diameter of the through hole is equivalent to the diameter of the hollow spoke (6); A second waterproof structure (8) is provided at one end of the hollow spoke (6) away from the first waterproof structure (7); the second waterproof structure (8) comprises a second threaded column (801), a rubber sealing ring (802) sleeved on the second threaded column (801), a second nut (803) pressed against one end of the rubber sealing ring (802) and threadedly connected to the second threaded column (801), a second nylon ferrule (804) pressed against one end of the second threaded column (801), and a clamping nut (805) pressed against one end of the second nylon ferrule (804) and threadedly connected to the second threaded column (801); A pressure relief nozzle (18) is also provided on the wheel hub shell (1) on a side opposite to the first waterproof structure (7).

2. A small and lightweight hub motor according to claim 1, characterized in that: The motor assembly comprises an iron core group (9) fixedly connected to a wheel hub shell (1), a rotatable rotor group (10) is arranged in the middle of the iron core group (9), and the rotor group (10) is mounted on a core shaft (2) via a bearing (11).

3. A small and lightweight hub motor according to claim 2, characterized in that: The planetary gear assembly comprises a sun gear (12), wherein the sun gear (12) is connected to the rotor assembly (10) via a flange (13), a plurality of planetary gears (14) are meshed on the outer side of the sun gear (12), the plurality of planetary gears (14) are mounted on a planetary support (15), the planetary support (15) is fixedly connected to a core shaft (2), an outer ring gear (16) is meshed on the outer side of the plurality of planetary gears (14), and the outer ring gear (16) is transmission-connected to the hub shell (1) via a one-way bearing (17).

4. A small and lightweight hub motor according to claim 3, characterized in that: The wheel hub shell (1) is composed of a wheel hub A shell (101) and a wheel hub B shell (102); the wheel hub A shell (101) and the wheel hub B shell (102) are connected via wheel hub bolts (103); and a stepped groove (104) for mounting a baffle (5) is provided in the wheel hub A shell (101).

5. A small and lightweight hub motor according to any one of claims 1 to 4, characterized in that: The invention also comprises a wheel rim (19) fixedly connected to one end of the plurality of hollow spokes (6), wherein a battery pack (3) is arranged in a circular array inside the wheel rim (19), wherein the battery pack (3) is connected to a wire (4), and an end of the wire (4) away from the battery pack (3) is electrically connected to a motor assembly of the wheel hub motor.

6. A small and lightweight hub motor according to claim 5, characterized in that: The wheel rim (19) is provided with a through hole for installing a second threaded column (801).

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