Hub motor for low-speed unmanned vehicle

Abstract

The invention discloses a hub motor which comprises a motor stator, a motor rotor, an encoder stator, an encoder rotor, a fixed shaft, a hub, a power-off brake assembly and a reduction gear assembly. The motor rotor is arranged on the outer side of the motor stator, the encoder rotor is arranged on the outer side of the encoder stator, the encoder rotor is fixedly connected to the motor rotor, and the encoder rotor rotates along with the motor rotor; the motor rotor and the encoder rotor are rotatably connected to the fixed shaft, and the encoder stator is connected to the fixed shaft; the hub is connected with the motor rotor through the reduction gear assembly, and the motor rotor drives the hub to rotate through the reduction gear assembly. The power-off braking assembly is at least used for braking the hub after the motor stator loses power, and the hub is prevented from rotating. The encoder is additionally arranged in the motor, so that the position information and the rotation angle of the motor rotor can be accurately detected and can be accurately controlled, and the rotation precision of the hub is high.

Description

Technical Field

[0001] The invention relates to a wheel hub motor, belonging to the technical field of motors. Background Art

[0002] An electric motor (commonly known as a "motor") is an electromagnetic device that converts or transmits electrical energy based on the law of electromagnetic induction.

[0003] The movement of a drone or wheelchair is driven by a wheel hub motor, but the existing wheel hub motor has inaccurate control of the rotation angle, resulting in low control accuracy. The existing wheel hub motor has low transmission efficiency and large size. At the same time, when the wheel hub motor suddenly loses power (especially when the drone or wheelchair is walking on a slope), the drone or wheelchair may slip, causing the drone or wheelchair to overturn, posing a safety hazard. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a hub motor for a low-speed unmanned vehicle which has high rotation angle control accuracy, high transmission efficiency, large torque, small structure, light weight, and braking effect when power is lost.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0006] A wheel hub motor comprises a motor stator, a motor rotor, an encoder stator, an encoder rotor, a fixed shaft, a wheel hub, a power-off brake assembly and a reduction gear assembly.

[0007] The motor stator drives the motor rotor to rotate at least when power is supplied; the motor rotor is arranged on the outside of the motor stator, and the motor rotor rotates at least under the drive of the motor stator; the encoder stator is at least used to detect the position information and rotation angle of the motor rotor; the encoder rotor is arranged on the outside of the encoder stator, and the encoder rotor is fixedly connected to the motor rotor, and the encoder rotor rotates with the motor rotor; the motor rotor and the encoder rotor are rotationally connected on a fixed shaft, and the encoder stator is connected to the fixed shaft; the wheel hub is connected to the motor rotor through a reduction gear assembly, and the motor rotor drives the wheel hub to rotate through the reduction gear assembly; the power-off brake assembly is at least used to brake the wheel hub after the motor stator loses power to prevent the wheel hub from rotating.

[0008] Furthermore, the motor rotor is connected to the outer surface of the fixed shaft through a fourth bearing; the encoder rotor is connected to the outer surface of the fixed shaft, and the encoder stator is installed on the fixed shaft through an encoder mounting seat.

[0009] Furthermore, the reduction gear assembly includes a sun gear connected to the motor rotor, the sun gear is externally meshed with a first planetary gear, a second planetary gear, a third planetary gear and a fourth planetary gear, the first planetary gear, the second planetary gear, the third planetary gear and the fourth planetary gear are externally meshed with a ring gear, and the outer wall of the ring gear is fixedly connected to the wheel hub.

[0010] Furthermore: a planetary carrier is provided on one side of the sun gear, and a first support column, a second support column, a third support column and a fourth support column are fixedly connected to the planetary carrier, the first support column corresponds to the position of the first planetary gear, and the first support column is connected to the first planetary gear through a first bearing; the second support column corresponds to the position of the second planetary gear, and the second support column is connected to the second planetary gear through a second bearing; the third support column corresponds to the position of the third planetary gear, and the third support column is connected to the third planetary gear through a third bearing.

[0011] Furthermore, a tire is provided on the outer surface of the wheel hub.

[0012] Furthermore, the power-off brake assembly includes a brake disc, which is fixed on the wheel hub and is provided with a plurality of brake grooves. A brake pin, a cylinder, an electromagnetic induction coil and a spring are provided on one side of the brake disc. When power is on, the brake pin retracts into the cylinder near one end of the brake disc under the action of the electromagnetic force of the electromagnetic induction coil. When power is off, the brake pin extends out into the brake groove under the action of the spring force.

[0013] Furthermore, a mounting frame is fixedly connected to one side of the cylinder, and a plurality of mounting holes are arranged on the mounting frame.

[0014] Furthermore, a shock absorbing ring is installed in each of the installation holes.

[0015] Compared with the prior art, the advantages of the present invention include:

[0016] 1) The wheel hub motor provided by the present invention has an encoder added to the motor, which can accurately detect the position information and rotation angle of the encoder rotor, that is, can accurately detect the position information and rotation angle of the motor rotor and can accurately control the position information and rotation angle of the motor rotor, so that the wheel hub rotates with high accuracy;

[0017] 2) The hub motor provided by the present invention uses a reduction gear assembly to drive the hub to rotate. Compared with the traditional direct-drive gear, the present invention has higher transmission efficiency, greater torque, and better load-bearing performance;

[0018] 3) The hub motor provided by the present invention includes a power-off brake assembly, which can brake when the hub motor loses power, preventing the drone or wheelchair from slipping due to sudden power failure when walking on a slope, thereby improving the safety of the drone or wheelchair. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the overall structure of a hub motor provided in a typical implementation case of the present invention;

[0021] Figure 2 It is a front view of a hub motor provided in a typical implementation case of the present invention;

[0022] Figure 3 It is a cross-sectional view of AA;

[0023] Figure 4 It is a structural schematic diagram of a reduction gear assembly provided in a typical implementation case of the present invention;

[0024] Figure 5 is a schematic structural diagram of a planet carrier provided in a typical implementation case of the present invention;

[0025] Figure 6 It is a structural schematic diagram of a power-off brake assembly provided in a typical implementation case of the present invention;

[0026] Explanation of the accompanying drawings: 2. Motor rotor; 3. Encoder stator; 4. Encoder rotor; 5. Fixed shaft; 6. Wheel hub; 7. Power-off brake assembly; 8. Reduction gear assembly; 9. Fourth bearing; 10. Tire; 11. Mounting frame; 12. Mounting hole; 13. Shock absorber ring; 81. Sun gear; 82. First planetary gear; 83. Second planetary gear; 84. Third planetary gear; 810. Fourth planetary gear; 85. Ring gear; 86. Planetary carrier; 87. First support column; 88. Second support column; 89. Third support column; 811. Fourth support column; 71. Brake disc; 72. Brake groove; 73. Brake pin; 74. Cylinder. DETAILED DESCRIPTION

[0027] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0028] The present invention discloses a hub motor, such as Figure 1-Figure 3 As shown, the wheel hub motor includes a motor stator, a motor rotor 2, an encoder stator 3, an encoder rotor 4, a fixed shaft 5, a wheel hub 6 and a power-off brake assembly 7. The encoder includes an encoder stator 3 and an encoder rotor 4. The outer surface of the wheel hub 6 is sleeved with a tire 10. The encoder stator 3 is at least used to detect the position information and rotation angle of the motor rotor 2; the encoder rotor 4 is arranged on the outside of the encoder stator 3, and the encoder rotor 4 is fixedly connected to the motor rotor 2, and the encoder rotor 4 rotates with the motor rotor 2; the encoder stator 3 is installed on the fixed shaft 5 through an encoder mounting seat, the wheel hub 6 is connected to the motor rotor 2 through a reduction gear assembly 8, and the motor rotor 2 drives the wheel hub 6 to rotate through the reduction gear assembly 8; the power-off brake assembly 7 is at least used to brake the wheel hub 6 after the motor stator loses power to prevent the wheel hub 6 from rotating.

[0029] The present invention adds an encoder to the motor, which can accurately detect the position information and rotation angle of the encoder rotor 4, that is, can accurately detect the position information and rotation angle of the motor rotor 2 and can accurately control the position information and rotation angle of the motor rotor 2, so that the wheel hub 6 rotates with high precision; the present invention adopts a reduction gear assembly 8 to drive the wheel hub 6 to rotate. Compared with the traditional direct-drive gear, the present invention has higher transmission efficiency, greater torque, and better load-bearing performance. The present invention includes a power-off brake assembly 7, which can brake when the wheel hub 6 motor loses power, prevent the drone or wheelchair from slipping due to sudden power failure when walking on a ramp, and improve the safety of the drone or wheelchair.

[0030] Specifically, Figure 3 As shown, the motor rotor 2 is connected to the outer surface of the fixed shaft 5 through the fourth bearing 9; the encoder rotor 4 is connected to the outer surface of the fixed shaft 5, and the encoder stator 3 is installed on the fixed shaft 5 through the encoder mounting seat. After the motor stator coil is energized, the motor stator drives the motor rotor 2 to rotate, and the motor rotor 2 drives the encoder rotor 4 to rotate. The encoder stator 3 detects the position information and rotation angle of the encoder rotor 4. Since the encoder rotor 4 is fixed on the motor rotor 2, the position information and rotation angle of the encoder rotor 4 are the position information and rotation angle of the motor rotor 2. Since the motor rotor 2 drives the wheel hub 6 to rotate through the reduction gear assembly 8, the encoder can accurately detect the position information and rotation angle of the wheel hub 6.

[0031] In some implementation cases, such as Figure 4 , Figure 5As shown, the reduction gear assembly 8 includes a sun gear 81 connected to the motor rotor 2, the outer portion of the sun gear 81 is meshedly connected with a first planetary gear 82, a second planetary gear 83, a third planetary gear 84 and a fourth planetary gear 810, the outer portions of the first planetary gear 82, the second planetary gear 83, the third planetary gear 84 and the fourth planetary gear 810 are meshedly connected with a ring gear 85, and the outer side wall of the ring gear 85 is fixedly connected to the wheel hub 6. A planet carrier 86 is provided on one side of the sun gear 81, and a first support column 87, a second support column 88, a third support column 89 and a fourth support column 811 are fixedly connected to the planet carrier 86, the first support column 87 corresponds to the position of the first planetary gear 82, and the first support column 87 is connected to the first planetary gear 82 through a first bearing; the second support column 88 corresponds to the position of the second planetary gear 83, and the second support column 88 is connected to the second planetary gear 83 through a second bearing; the third support column 89 corresponds to the position of the third planetary gear 84, and the third support column 89 is connected to the third planetary gear 84 through a third bearing. The motor rotor 2 rotates under the drive of the motor stator. Since the motor rotor 2 is fixedly connected to the sun gear 81, the motor rotor 2 drives the sun gear 81 to rotate during its rotation. Then, the sun gear 81 rotates to drive the first planetary gear 82, the second planetary gear 83, the third planetary gear 84 and the fourth planetary gear 810 meshing therewith, thereby driving the ring gear 85 to rotate. The ring gear 85 rotates to drive the wheel hub 6 to rotate, thereby driving the unmanned vehicle or wheelchair to move. The present invention drives multiple large-diameter planetary gears to rotate through a small-diameter sun gear 81, so that the output torque is large and the torque transmission efficiency is high, and at the same time, the load-bearing performance of the unmanned vehicle or wheelchair is good.

[0032] Specifically, Figure 6As shown, the power-off brake assembly 7 includes a brake disc 71, and the brake disc 71 is fixed on the wheel hub 6. The brake disc 71 is provided with a plurality of brake grooves 72. Preferably, the brake grooves 72 in this embodiment are arc-shaped waist-shaped grooves; a brake pin 73, a cylinder 74, an electromagnetic induction coil and a spring are provided on one side of the brake disc 71. When power is on, the brake pin 73 retracts into the cylinder 74 near one end of the brake disc 71 under the action of the electromagnetic force of the electromagnetic induction coil. When power is off, the brake pin 73 extends out into the brake groove 72 under the action of the spring force. More specifically, the cylinder 74 is provided with a brake pin 73, a cylinder 74, an electromagnetic induction coil and a spring. A spring is arranged, and when the power is on, the brake pin 73 overcomes the force of the spring and retracts into the cylinder 74. When the unmanned vehicle or wheelchair fails and the power is suddenly cut off, the electromagnetic force disappears, and the brake pin 73 extends under the action of the spring force and is inserted into the brake groove 72, so that the brake disc 71 stops rotating. Since the brake disc 71 is connected to the wheel hub 6, the wheel hub 6 also stops rotating, and the sun gear 81, the planetary gears (the first planetary gear 82, the second planetary gear 83, the third planetary gear 84 and the fourth planetary gear 810), the ring gear 85 and the wheel hub 6 also stop rotating, preventing the car from sliding on the ramp and improving the safety factor. Preferably, a mounting frame 11 is fixedly connected to one side of the cylinder 74, and a plurality of mounting holes 12 are provided on the mounting frame 11. The wheel hub 6 motor is connected to the frame through the plurality of mounting holes 12. Preferably, a shock absorbing ring 13 is installed in each of the mounting holes 12, and the installation of the shock absorbing ring 13 in the mounting hole 12 can reduce the vibration generated by the vehicle body and improve the comfort of the user.

[0033] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A hub motor, characterized in that: include A motor stator, the motor stator driving the motor rotor (2) to rotate at least when powered on; A motor rotor (2), the motor rotor (2) being arranged outside the motor stator, and the motor rotor (2) being rotated at least under the drive of the motor stator; An encoder stator (3), the encoder stator (3) being used at least to detect position information and a rotation angle of a motor rotor (2); An encoder rotor (4), the encoder rotor (4) being arranged outside the encoder stator (3), and the encoder rotor (4) being fixedly connected to the motor rotor (2), and the encoder rotor (4) rotating along with the motor rotor (2); A fixed shaft (5), the motor rotor (2) and the encoder rotor (4) are rotatably connected to the fixed shaft (5), and the encoder stator (3) and the motor stator are connected to the fixed shaft (5); A wheel hub (6), wherein the wheel hub (6) is connected to the motor rotor (2) via a reduction gear assembly (8), and the motor rotor (2) drives the wheel hub (6) to rotate via the reduction gear assembly (8); A power-off braking assembly (7) is provided, wherein the power-off braking assembly (7) is at least used to brake the wheel hub (6) after the motor stator loses power, thereby preventing the wheel hub (6) from rotating.

2. The hub motor according to claim 1, characterized in that: The motor rotor (2) is connected to the outer surface of the fixed shaft (5) via a fourth bearing (9); the encoder rotor (4) is connected to the outer surface of the fixed shaft (5); and the encoder stator (3) is fixed to the shaft (5) via an encoder mounting seat.

3. The hub motor according to claim 1, characterized in that: The reduction gear assembly (8) comprises a sun gear (81) connected to the motor rotor (2); the sun gear (81) is externally meshed with a first planetary gear (82), a second planetary gear (83), a third planetary gear (84) and a fourth planetary gear (810); the first planetary gear (82), the second planetary gear (83), the third planetary gear (84) and the fourth planetary gear (810) are externally meshed with a ring gear (85); the outer side wall of the ring gear (85) is fixedly connected to the wheel hub (6).

4. The hub motor according to claim 3, characterized in that: A planet carrier (86) is provided on one side of the sun gear (81), and a first support column (87), a second support column (88), a third support column (89) and a fourth support column (811) are fixedly connected to the planet carrier (86), wherein the first support column (87) corresponds to the position of the first planetary gear (82), and the first support column (87) is connected to the first planetary gear (82) through a first bearing; the second support column (88) corresponds to the position of the second planetary gear (83), and the second support column (88) is connected to the second planetary gear (83) through a second bearing; the third support column (89) corresponds to the position of the third planetary gear (84), and the third support column (89) is connected to the third planetary gear (84) through a third bearing.

5. The hub motor according to claim 1, characterized in that: The outer surface of the wheel hub (6) is provided with a tire (10).

6. The hub motor according to claim 1, characterized in that: The power-off brake assembly (7) comprises a brake disc (71), the brake disc (71) is fixed on the wheel hub (6), a plurality of brake grooves (72) are arranged on the brake disc (71), a brake pin (73), a cylinder (74), an electromagnetic induction coil and a spring are arranged on one side of the brake disc (71), when power is on, the brake pin (73) is retracted into the cylinder (74) at one end close to the brake disc (71) under the action of the electromagnetic force of the electromagnetic induction coil, and when power is off, the brake pin (73) is extended into the brake groove (72) under the action of the spring force.

7. The hub motor according to claim 1, characterized in that: A mounting frame (11) is fixedly connected to one side of the cylinder (74), and a plurality of mounting holes (12) are provided on the mounting frame (11).

8. The wheel hub motor according to claim 7, characterized in that: A shock absorbing ring (13) is installed in each of the installation holes (12).

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