Hub motor

Abstract

The utility model provides a wheel hub motor, a planet carrier is provided with a central through hole, the central axis of the central through hole and the rotation axis of a planet wheel are coaxially arranged, the axial direction of a fixed shaft is provided with a threading channel, one end of a wire is connected with a motor assembly, and the other end of the wire sequentially passes through the central through hole and the threading channel and extends out of the fixed shaft. The threading channel is formed in the axial direction, the machining difficulty is greatly reduced, meanwhile, an airflow path for axial heat dissipation is provided, and heat accumulation in the motor is reduced; in addition, the central axis of the central through hole and the rotating axis of the planet wheel are coaxially arranged, interference between the wire and other structures is avoided, the wire is protected against damage, and the compactness of the whole structure is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to a hub motor. Background Art

[0002] In-wheel motors are integrated directly into the wheel, eliminating complex drivetrains such as gearboxes, drive shafts, differentials, belts, chains, or gear sets. This makes the device extremely compact and frees up valuable internal space. This is crucial for space-constrained devices such as robot vacuums, small power tools, and compact lawn mowers, as it allows for larger batteries or other components.

[0003] Chinese patent document "CN219697434U" discloses a hub motor with an internal speed change mechanism. A cable routing channel is provided on the through-shaft, extending from the motor's core position through the housing's axial hole and connecting to the exterior of the hub shell. The motor's lead-out cables are routed through this routing channel to the exterior of the hub shell. This hub motor utilizes an oblique channel machining method, which makes it difficult to manufacture and prone to significant coaxial deviation. Furthermore, the oblique channel, which penetrates the shaft, blocks the axial heat dissipation airflow path, leading to heat accumulation within the motor. Utility Model Content

[0004] In view of this, the purpose of the present invention is to provide a hub motor, which aims to solve the problem that the hub motor in the prior art adopts the processing method of oblique holes, which makes the processing more difficult and is prone to large coaxiality deviation of the oblique holes. In addition, the oblique holes pass through the shaft body, blocking the air flow path for axial heat dissipation, resulting in heat accumulation inside the motor.

[0005] The utility model provides a hub motor, comprising a housing, a fixed shaft, a planetary carrier, a planetary gear, a motor assembly and a wire, wherein the housing has an accommodating cavity, the planetary carrier and the motor assembly are both located in the accommodating cavity, one end of the fixed shaft extends into the accommodating cavity and is connected to the planetary carrier, and the other end extends outside the housing, the planetary gear is rotatably connected to the planetary carrier, the motor assembly is located on a side of the planetary carrier away from the fixed shaft, and the motor assembly drives the housing to rotate relative to the fixed shaft through the planetary gear, a central through hole is provided on the planetary carrier, the central axis of the central through hole is coaxially arranged with the rotation axis of the planetary gear, a threading channel is provided in the axial direction of the fixed shaft, one end of the wire is connected to the motor assembly, and the other end passes through the central through hole and the threading channel in sequence and extends to the outside of the fixed shaft.

[0006] According to some embodiments of the present invention, the planetary carrier includes an upper enclosing plate and a lower enclosing plate, both of which are provided with the central through hole, and an installation groove is formed between the upper enclosing plate and the lower enclosing plate, and the installation groove allows the planetary gear to be embedded along the radial direction of the planetary carrier.

[0007] According to some embodiments of the present invention, a wheel axle is connected to the central through hole, and the wheel axle is used to fix the planetary gear in the installation groove. The wheel axle is a hollow structure for the wire to pass through.

[0008] According to some embodiments of the present invention, the planet carrier and the fixed shaft adopt an integrated structure.

[0009] According to some embodiments of the present invention, the motor assembly is provided with a sun gear meshing with the planetary gears, and the housing is provided with a ring gear meshing with the planetary gears, and the sun gear is used to drive the ring gear together with the housing to rotate through the planetary gears.

[0010] According to some embodiments of the present invention, the motor assembly includes a stator, a rotor and a motor shaft, the stator is fixedly arranged relative to the planetary carrier, one end of the motor shaft is fixedly connected to the rotor, and the other end is connected to the sun gear, and the stator is used to drive the rotor together with the motor shaft to rotate relative to the planetary carrier, thereby driving the sun gear to rotate.

[0011] According to some embodiments of the present invention, an installation chamber is provided on the planetary carrier, and a plurality of installation steps are arranged in sequence along the axial direction of the planetary carrier in the installation chamber, and the inner diameter sizes of the plurality of installation steps decrease gradually. Each installation step is used to install a bearing that matches its inner diameter, and the installation direction of the bearing points from the installation step with the largest inner diameter to the installation step with the smallest inner diameter, so that the bearings are pressed into the installation chamber in ascending order of outer diameter, and the inner ring of the bearing is connected to the shaft body of the motor shaft.

[0012] According to some embodiments of the present invention, a protrusion is provided at the bottom of the box body, and the protrusion extends toward the axial direction of the fixed shaft. The rotor is provided with a recess corresponding to the protrusion, and the recess is accessible to the protrusion.

[0013] According to some embodiments of the present invention, the motor assembly further includes a driving plate, on which a plug-in terminal is provided, and a central axis of a notch of the plug-in terminal is parallel to the driving plate.

[0014] According to some embodiments of the present invention, a flattened plane is provided at one end of the fixed shaft extending outside the box body, the normal direction of the flattened plane is parallel to the radial direction of the fixed shaft, and a thread is provided at a position on the fixed shaft corresponding to the flattened plane.

[0015] Beneficial Effects: The present invention provides a hub motor having a central through-hole formed in a planetary carrier, the central axis of the central through-hole being coaxial with the rotational axis of the planetary gear, and a wire passage being formed in the axial direction of the fixed shaft. One end of the wire is connected to the motor assembly, and the other end extends out of the fixed shaft through the central through-hole and the wire passage in sequence. The wire passage in the present invention is formed axially, greatly reducing the difficulty of machining, while providing an airflow path for axial heat dissipation and reducing heat accumulation within the motor. Furthermore, the central axis of the central through-hole is coaxial with the rotational axis of the planetary gear, avoiding interference between the wire and other structures, protecting the wire from damage, and improving the compactness of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Fig. 1 This is a schematic diagram of the structure of the hub motor of the utility model;

[0018] Fig. 2 This is a schematic diagram of the internal structure of the hub motor of the utility model;

[0019] Fig. 3 This is a schematic structural diagram of the fixed shaft and planetary carrier of the utility model;

[0020] Fig. 4 This is a structural schematic diagram of the fixed shaft and planetary carrier from another perspective of the present invention.

[0021] In the figure: 1. Box body; 11. Accommodating chamber; 12. Ring gear; 13. Protrusion; 14. First cover body; 15. Second cover body; 2. Fixed shaft; 21. Threading channel; 22. Flat plane; 23. Thread; 3. Planet carrier; 31. Center through hole; 32. Upper enclosure plate; 33. Lower enclosure plate; 34. Mounting groove; 35. Axle; 36. Mounting chamber; 37. Mounting step; 38. Bearing; 4. Planetary gear; 5. Motor assembly; 51. Stator; 52. Rotor; 521. Recessed portion; 53. Motor shaft; 54. Drive plate; 541. Plug terminal; 6. Wire; 7. Sun gear. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] See also Figs. 1 to 4 The present invention provides a hub motor, comprising a housing 1, a fixed shaft 2, a planetary carrier 3, a planetary gear 4, a motor assembly 5 and a wire 6. The housing 1 has an accommodating cavity 11, the planetary carrier 3 and the motor assembly 5 are both located in the accommodating cavity 11, one end of the fixed shaft 2 extends into the accommodating cavity 11 and is connected to the planetary carrier 3, and the other end extends to the outside of the housing 1, the planetary gear 4 is rotatably connected to the planetary carrier 3, the motor assembly 5 is located on the side of the planetary carrier 3 away from the fixed shaft 2, and the motor assembly 5 drives the housing 1 to rotate relative to the fixed shaft 2 through the planetary gear 4. A central through hole 31 is opened on the planetary carrier 3, and the central axis of the central through hole 31 is coaxially arranged with the rotation axis of the planetary gear 4. A threading channel 21 is opened in the axial direction of the fixed shaft 2, one end of the wire 6 is connected to the motor assembly 5, and the other end passes through the central through hole 31 and the threading channel 21 in sequence and extends to the outside of the fixed shaft 2.

[0024] The threading channel 21 in the present application is opened axially, which greatly reduces the difficulty of processing, and at the same time provides an airflow path for axial heat dissipation, reducing heat accumulation inside the motor; in addition, the central axis of the central through hole 31 is coaxially arranged with the rotation axis of the planetary gear 4, avoiding interference between the wire 6 and other structures, protecting the wire 6 from damage, and improving the compactness of the overall structure.

[0025] Furthermore, the planet carrier 3 and fixed shaft 2 are integrally constructed, die-cast from a zinc alloy to form a rigid, non-detachable connection. This integration of the traditionally separate planet carrier 3 and fixed shaft 2 into a single metal body eliminates the need for bolts, splines, and other interfaces, addressing issues such as fretting wear and accumulated assembly errors between the planet carrier 3 and fixed shaft 2. This integrated structure improves the center positioning accuracy of the planetary gear train and provides more even meshing load distribution.

[0026] The housing 1 includes a first cover 14 and a second cover 15. The second cover 15 is fixedly connected to the first cover 14. Specifically, the first and second covers 14, 15 are fixed together by four copper nuts. The first and second covers 14, 15 enclose a housing chamber 11. The first and second covers 14, 15 are used to prevent external impurities from entering the housing chamber 11, thereby protecting the components of the hub motor located within the housing chamber 11 to ensure long-term normal operation and increase the service life of the hub motor. The first and second covers 14, 15 are both made of glass-fiber reinforced nylon, which combines strength and noise reduction.

[0027] According to some embodiments of the present invention, the planetary carrier 3 includes an upper enclosing plate 32 and a lower enclosing plate 33, each of which is provided with the central through hole 31. A mounting groove 34 is formed between the upper enclosing plate 32 and the lower enclosing plate 33, and the mounting groove 34 allows the planetary gear 4 to be embedded in the radial direction of the planetary carrier 3. Similarly, in this embodiment, the upper enclosing plate 32 and the lower enclosing plate 33 are an integral structure. Therefore, the traditional installation method of placing the planetary gear 4 on the planetary carrier 3 along the axial direction is not applicable to the planetary carrier 3 with an integral structure. Therefore, when using the planetary carrier 3 in this embodiment for installation, the planetary gear 4 is embedded in the planetary carrier 3 along the radial direction and then fixed, which greatly improves the assembly efficiency.

[0028] According to some embodiments of the present invention, a wheel axle 35 is connected to the central through hole 31 , and the wheel axle 35 is used to fix the planetary gear 4 in the mounting groove 34 . The wheel axle 35 is a hollow structure for the wire 6 to pass through.

[0029] According to some embodiments of the present invention, the motor assembly 5 is provided with a sun gear 7 that meshes with the planetary gears 4, and the housing 1 is provided with a ring gear 12 that meshes with the planetary gears 4. The sun gear 7 is used to drive the ring gear 12 to rotate together with the housing 1 through the planetary gears 4. The sun gear 7 is used to drive the ring gear 12 to rotate together with the housing 1 through the planetary gears 4. A plurality of planetary gears 4 are provided, and the plurality of planetary gears 4 are arranged around the sun gear 7. For example, three planetary gears 4 can be provided. In this embodiment, the sun gear 7 and the motor shaft 53 can be provided independently of each other. The sun gear 7 is constructed as an independent component. The sun gear 7 can be sleeved on the motor shaft 53 and fixedly connected to the motor shaft 53. In some other embodiments, the sun gear 7 and the motor shaft 53 are integrally formed to improve the integration of the hub motor and make the hub motor structure compact.

[0030] According to some embodiments of the present invention, the motor assembly 5 includes a stator 51, a rotor 52, and a motor shaft 53. The stator 51 is fixed relative to the planetary carrier 3. One end of the motor shaft 53 is fixedly connected to the rotor 52, and the other end is connected to the sun gear 7. The stator 51 is used to drive the rotor 52 and the motor shaft 53 to rotate relative to the planetary carrier 3, thereby driving the sun gear 7 to rotate. For example, the stator 51 may be provided with a coil winding, and the rotor 52 may be provided with a magnet. The motor shaft 53 is coaxial with the planetary carrier 3 and the fixed shaft 2, and the central axis of the motor shaft 53 coincides with the central axis of the mounting shaft. The rotor 52 can be provided independently of the motor shaft 53. The rotor 52 and the motor shaft 53 can be fixedly connected together by bonding, clamping, welding, screwing, etc. In some embodiments, the rotor 52 can be integrally formed with the motor shaft 53 to improve the integration of the motor assembly 5.

[0031] According to some embodiments of the present invention, the planet carrier 3 is provided with a mounting chamber 36. Within this chamber 36, several mounting steps 37 are arranged axially along the planet carrier 3. The inner diameters of these mounting steps 37 decrease in a gradient. Each mounting step 37 is used to mount a bearing 38 corresponding to its inner diameter. The bearing 38 is installed in a direction from the mounting step 37 with the largest inner diameter to the mounting step 37 with the smallest inner diameter, so that the bearings 38 are press-fitted into the mounting chamber 36 in ascending order of outer diameter. The inner rings of the bearings 38 are connected to the shaft of the motor shaft 53. In this embodiment, since the inner diameters of the mounting steps 37 vary, the bearings 38 can be press-fitted into the mounting chamber 36 in ascending order of outer diameter on the same side during installation, thereby reducing the difficulty of the assembly process. For example, two mounting steps 37 are provided: one adjacent to the sun gear 7 with a smaller diameter, and the other, further away from the sun gear 7 with a larger diameter. Therefore, during installation, the smaller diameter bearing 38 is installed first, followed by the larger diameter bearing 38.

[0032] In some other feasible embodiments, the inner peripheral wall of the mounting chamber 36 is formed with a uniform inner diameter for mounting bearings 38 of the same size. Accordingly, a retaining groove for placing a retaining spring is formed on the inner peripheral wall of the mounting chamber 36, and the retaining spring is used to secure the bearing 38.

[0033] According to some embodiments of the present invention, a protrusion 13 is provided at the bottom of the housing 1, and the protrusion 13 extends in the axial direction of the fixed shaft 2. The rotor 52 is provided with a recessed portion 521 corresponding to the protrusion 13, and the recessed portion 521 can be entered by the protrusion 13. In this embodiment, the protrusion 13 is a bottom bearing 38 provided on the housing 1. The bottom bearing 38 of the housing 1 is connected to the motor shaft 53, thereby improving the stability of the motor shaft 53 during rotation. Since the protrusion 13 occupies axial space, in order to avoid the protrusion 13 from affecting the rotor 52, the rotor 52 correspondingly forms a recessed portion 521 corresponding to the protrusion 13, thereby reducing the axial space occupied by the rotor 52 when the rotor 52 is installed in the accommodating cavity 11.

[0034] According to some embodiments of the present invention, the motor assembly 5 also includes a drive plate 54, on which a plug-in terminal 541 is provided. The central axis of the slot of the plug-in terminal 541 is parallel to the drive plate 54, thereby reducing the axial space occupied by the plug-in terminal 541, making the structure of the motor assembly 5 more compact.

[0035] According to some embodiments of the present invention, a flattened surface 22 is provided at one end of the fixed shaft 2 extending outside the housing 1. The normal direction of the flattened surface 22 is parallel to the radial direction of the fixed shaft 2. Threads 23 are provided on the fixed shaft 2 at a position corresponding to the flattened surface 22. In this embodiment, the flattened surface 22 contacts a flat surface on the device, blocking the circumferential rotational freedom of the fixed shaft 2. This replaces traditional keyways / splines and eliminates vibration and noise caused by clearance. Furthermore, the threads 23 provided on the flattened surface 22 further ensure the secure connection and adjustability of the fixed shaft 2 to the device.

[0036] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present application is defined by the appended claims, not the foregoing description, and all variations within the meaning and scope of the appended claims are intended to be included herein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0037] The above-described embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A hub motor, characterized in that: The invention comprises a housing (1), a fixed shaft (2), a planetary carrier (3), a planetary gear (4), a motor assembly (5) and a wire (6), wherein the housing (1) has a receiving cavity (11), the planetary carrier (3) and the motor assembly (5) are both located in the receiving cavity (11), one end of the fixed shaft (2) extends into the receiving cavity (11) and is connected to the planetary carrier (3), and the other end extends outside the housing (1), the planetary gear (4) is rotatably connected to the planetary carrier (3), and the motor assembly (5) is located on the planetary carrier (3) away from the fixed shaft. On one side of the shaft (2), the motor assembly (5) drives the box (1) to rotate relative to the fixed shaft (2) through the planetary gear (4); a central through hole (31) is provided on the planetary frame (3); the central axis of the central through hole (31) is coaxially arranged with the rotation axis of the planetary gear (4); a threading channel (21) is provided in the axial direction of the fixed shaft (2); one end of the wire (6) is connected to the motor assembly (5), and the other end passes through the central through hole (31) and the threading channel (21) in sequence and extends to the outside of the fixed shaft (2).

2. The hub motor according to claim 1, characterized in that: The planet carrier (3) comprises an upper enclosure plate (32) and a lower enclosure plate (33), both of which are provided with the central through hole (31), and a mounting groove (34) is formed between the upper enclosure plate (32) and the lower enclosure plate (33), and the mounting groove (34) allows the planet gear (4) to be embedded along the radial direction of the planet carrier (3).

3. The hub motor according to claim 2, characterized in that: A wheel axle (35) is connected to the central through hole (31), and the wheel axle (35) is used to fix the planetary gear (4) in the mounting groove (34). The wheel axle (35) is a hollow structure for the wire (6) to pass through.

4. The hub motor according to claim 1, characterized in that: The planet carrier (3) and the fixed shaft (2) adopt an integrated structure.

5. The hub motor according to claim 1, characterized in that: The motor assembly (5) is provided with a sun gear (7) meshing with the planetary gears (4), and the housing (1) is provided with a ring gear (12) meshing with the planetary gears (4). The sun gear (7) is used to drive the ring gear (12) and the housing (1) to rotate through the planetary gears (4).

6. The hub motor according to claim 5, characterized in that: The motor assembly (5) comprises a stator (51), a rotor (52) and a motor shaft (53); the stator (51) is fixedly arranged relative to the planetary carrier (3); one end of the motor shaft (53) is fixedly connected to the rotor (52), and the other end is connected to the sun gear (7); the stator (51) is used to drive the rotor (52) and the motor shaft (53) to rotate relative to the planetary carrier (3), thereby driving the sun gear (7) to rotate.

7. The hub motor according to claim 6, characterized in that: The planet carrier (3) is provided with a mounting chamber (36), and a plurality of mounting steps (37) are sequentially arranged in the axial direction of the planet carrier (3) in the mounting chamber (36), and the inner diameters of the plurality of mounting steps (37) decrease gradually. Each mounting step (37) is used to mount a bearing (38) that matches its inner diameter. The mounting direction of the bearing (38) points from the mounting step (37) with the largest inner diameter to the mounting step (37) with the smallest inner diameter, so that the bearings (38) are press-fitted into the mounting chamber (36) in ascending order of outer diameter. The inner ring of the bearing (38) is connected to the shaft body of the motor shaft (53).

8. The hub motor according to claim 6, characterized in that: The bottom of the box body (1) is provided with a protrusion (13), the protrusion (13) extending toward the axial direction of the fixed shaft (2), and the rotor (52) is provided with a recess (521) corresponding to the protrusion (13), the recess (521) allowing the protrusion (13) to enter.

9. The hub motor according to claim 1, characterized in that: The motor assembly (5) further comprises a driving plate (54), wherein a plug-in terminal (541) is provided on the driving plate (54), and a central axis of a notch of the plug-in terminal (541) is parallel to the driving plate (54).

10. The hub motor according to claim 1, characterized in that: One end of the fixed shaft (2) extending outside the box body (1) is provided with a flat plane (22), the normal direction of the flat plane (22) is parallel to the radial direction of the fixed shaft (2), and a thread (23) is provided at a position on the fixed shaft (2) corresponding to the flat plane (22).

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