Oil seal for inner hole positioning installation and hub motor thereof

Abstract

The utility model relates to an oil seal positioned and installed in an inner hole and a hub motor thereof. According to the oil seal positioned and installed in the inner hole, an oil seal body comprises a metal framework and an elastic body, the metal framework is embedded in the elastic body, the oil seal is provided with a sealing lip part and an assembling inner hole, the sealing lip part is of a circumferential structure, the diameter of the sealing lip part is larger than that of the assembling inner hole, and the assembling inner hole is formed in the assembling inner hole. And the difference value range between the diameter of the sealing lip part and the diameter of the assembling inner hole is greater than or equal to 4mm. The oil seal and the motor thereof have the beneficial effects that the oil seal and the motor thereof have more excellent airtight and waterproof functions of the motor, the oil seal is fully lubricated, the rotary sealing resistance is small, the motor efficiency is high, the service life is long, the abrasion of the oil seal is obviously slowed down by the grease storage groove structure, and the service life of the oil seal is prolonged; the opening direction of the oil seal is opposite to the external environment, the working environment of the oil seal is greatly optimized, the service life of the oil seal is greatly prolonged, and the waterproof service life of the motor is also prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of wheel hub motors, and specifically discloses an oil seal with inner hole positioning installation and a wheel hub motor thereof. Background Art

[0002] With the promotion of the global low-carbon concept, a wave of electric vehicles replacing oil vehicles has emerged worldwide. In my country, two-wheeled electric vehicles are widely used as a means of transportation for people's daily transportation. The country has also issued a series of policies for the management of two-wheeled electric vehicles, such as the "Electric Bicycle Safety Technical Specification" (GB17761-2018), a new national standard for electric bicycles. The new national standard strictly restricts a series of configurations of the whole vehicle, especially in terms of weight, speed, power and drive structure. For example, the whole vehicle needs to have a flywheel pedal drive structure; the size of the axial opening of the hub motor is limited, etc. Many manufacturers have begun to focus on optimizing the motor performance by improving the structure of the hub motor. For example, the development of non-standard flywheels has appeared on the market to improve the motor output power. For the new national standard hub motor, its motor power is limited by the motor weight, motor output structure, and motor size. The existing motor still cannot effectively break through the limitations of the above factors to improve the motor's power performance.

[0003] For example, the oil seals disclosed in the Chinese patents / applications with application publication number CN117267379A; application publication number CN117628186A; application publication number CN117948430A; authorization announcement number CN221033957U; authorization announcement number CN220980329U; authorization announcement number CN221033958U, etc. In these disclosed prior art documents, without exception, the oil seals with the outer ring used for assembly and fixed connection and the inner hole used for forming a rotating sealing structure are disclosed. This outer solid inner seal oil seal structure,

[0004] For the new national standard hub motor, the installation size of its national standard flywheel strictly limits the thickness of the motor's lead wire, which in turn limits the motor's current overload capacity, resulting in a small peak stall torque of the motor, a long acceleration time for repeated start and stop of the motor, and a waste of electricity, and weak overall motor power characteristics. Because the inner hole of the flywheel installation limits the size of the matching part of the end cover, the oil seal is installed in the inner hole of the threaded structure of the end cover, and the oil seal requires a certain amount of space, which makes it impossible to enlarge the sealing inner hole of the oil seal, and the lead wire of the motor is on the shaft. First of all, the shaft cannot be thick, and the lead wire can only be made thin, and the current carrying capacity is weak. This is the main factor that limits the new national standard hub motor's output torque and short-term overload capacity. Therefore, how to increase the square number of the motor's lead wires under the restrictions of the national standard flywheel structure, thereby improving the motor's output torque characteristics and current overload capacity, is the goal that the hub motor manufacturers in the industry are constantly working hard to achieve. Utility Model Content

[0005] In view of the deficiencies of the prior art, the utility model discloses an oil seal with a fixed inner hole, a rotary seal on an outer ring and an inner hole positioning installation for expanding the outlet space of the motor lead wire and a hub motor thereof.

[0006] In order to achieve the above-mentioned purpose, the utility model discloses an oil seal for inner hole positioning installation, and its technical solution is as follows:

[0007] An oil seal for positioning and installation in an inner hole, wherein the oil seal body comprises a metal frame and an elastomer, wherein the metal frame is embedded in the elastomer, and wherein the oil seal body is provided with a sealing lip and an assembly inner hole, wherein the sealing lip is a circumferential structure, wherein the diameter of the sealing lip is greater than the diameter of the assembly inner hole, and the difference between the diameter of the sealing lip and the diameter of the assembly inner hole is ≥4mm. This scheme expands the sealing lip from the inner hole rotation seal to the rotating body part outside the shaft, and while maintaining the assembly structure and assembly dimensions of the hub motor, breaks through the limitation of the size of the threaded mating part of the hub motor end cover of the new national standard, and can effectively thicken the diameter of the hub motor shaft, and also provides sufficient space for the outlet of the lead wires with a larger square number. In addition, the diameter difference range set by this scheme is ≥4mm, which fully guarantees the strength of the sealing structure.

[0008] As a further optimization of the above technical solution: the oil seal body is located outside the rotating structure, and the sealing lip forms a dynamic rotating seal with the matching rotating structure. This solution moves the rotating seal matching structure outward and is tailor-made for the outer rotor hub motor.

[0009] As a further optimization of the above technical solution: a shaft is passed through the assembly inner hole, and the assembly inner hole and the shaft form an interference fit fixed connection.

[0010] As a further optimization of the above technical solution: the oil seal body is provided with a grease storage groove, and the grease storage groove is located between the sealing lip and the assembly inner hole. The grease storage structure of this solution ensures a long-term, continuous and sufficient lubrication environment for the motor, effectively reduces the rotation resistance of the oil seal, reduces its loss, and slows down the wear of the oil seal lip, avoiding the problem of dry grinding of the oil seal lip after the grease of the existing oil seal structure dries up, and effectively prolongs the service life and sealing effect of the oil seal.

[0011] The utility model also discloses a hub motor, comprising the oil seal installed by positioning the inner hole in the above technical solution, and also comprising a support cover, the support cover is the rotating structure, the mating surface between the support cover and the sealing lip is a circumferential surface, and the front section of the mating part of the rotating structure is provided with a guiding inclined surface. This solution conforms to the assembly characteristics of the hub motor and effectively avoids the assembly damage of the oil seal lip.

[0012] Compared with the prior art, the advantages and positive effects of the utility model are:

[0013] In view of the structural and size limitations of the new national standard hub motor standard parts, the utility model has specially developed an oil seal with an "inner hole fixed, outer ring rotating seal" structure, so as to expand the outlet space of the motor lead wires and increase the square number of outlet wires, so as to improve the current overload capacity of the motor. At the same time, the grease storage tank is reasonably designed to store sufficient spare grease to supply the grease loss of the motor during long-term operation for a long time. The oil seal has low resistance, sufficient lubrication and long service life.

[0014] The electric vehicle hub motor provided by the utility model is used to drive electric vehicles. Compared with existing electric vehicle motors, it has excellent airtight and waterproof functions, the oil seal is fully lubricated, the rotation seal resistance is small, the motor efficiency is high, and the service life is long, which is particularly suitable for the use scenarios of new national standard motors; the grease storage tank structure of the oil seal of the utility model significantly reduces the wear of the oil seal and extends its service life; the motor of the utility model, the radial size of the sealing lip is larger than the size of the assembly inner hole, providing a larger space for the lead-out wires of the motor, and the square number of the lead-out wires is significantly increased, thereby greatly improving the current overload capacity of the motor; when the oil seal of the motor of the utility model is installed, the direction of the oil seal opening is away from the external environment, which greatly optimizes the working environment of the oil seal. Different from the conventional installation method of the oil seal with the sealing lip facing outward, the motor structure of the utility model effectively avoids the situation where the sealing lip of the oil seal is eroded by external foreign objects or the natural environment, greatly extending the service life of the oil seal, and also extending the waterproof life of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the cross-sectional structure of the oil seal body in the utility model.

[0016] Figure 2 It is a schematic diagram of the assembly structure of the oil seal body in the utility model.

[0017] Figure 3 for Figure 2 Schematic diagram of the enlarged structure at point A in the middle.

[0018] Figure 4 This is a schematic diagram of the assembly structure of the hub motor in the utility model

[0019] In the figure, 1. oil seal body; 2. rotating structure; 3. rotor; 4. stator; 5. shaft; 6. bearing; 11. metal frame; 12. elastomer; 13. grease storage tank; 31. rim; 32. magnetic ring; 33. permanent magnet; 41. stator core; 42. enameled wire; 43. bracket; 44. bushing; 121. sealing lip; 122. assembly inner hole. DETAILED DESCRIPTION

[0020] The following are specific embodiments of the present invention and the technical solution of the present invention are further described in detail in conjunction with the accompanying drawings. It should be noted that the described embodiments are only intended to facilitate the understanding of the present invention by those skilled in the art and do not have any limiting effect on the protection scope of the present invention.

[0021] Embodiment 1:

[0022] See also Figure 1 , 2 As shown in Figures 3 and 4, the present embodiment provides an oil seal for positioning and installing an inner hole. The oil seal body 1 includes a metal frame 11 and an elastic body 12. The metal frame 11 is embedded in the elastic body 12 to play a supporting role. The oil seal body 1 is a rotating body structure. A sealing lip 121 and an assembly inner hole 122 are provided on the oil seal body 1. The sealing lip 121 is a circumferential structure. The diameter of the sealing lip 121 is larger than the diameter of the assembly inner hole 122. The difference between the diameter of the sealing lip 121 and the diameter of the assembly inner hole 122 is ≥4 mm.

[0023] The oil seal body 1 is located on the axial outer side of the rotating structure 2, and a gap is left between the oil seal body 1 and the outer side of the rotating structure 2. The oil seal body 1 is provided with a grease storage groove 13, and the grease storage groove 13 is located between the sealing lip 121 and the assembly inner hole 122. The rotating structure 2 partially extends into the grease storage groove 13 of the oil seal body 1 in the axial direction, and the sealing lip 121 of the oil seal body 1 and the extending part of the rotating structure 2 form an elastic interference rotary seal fit, and the spare lubricating grease is stored in the grease storage groove 13. A guide slope is provided at the front section of the matching part of the rotating structure 2. The assembly inner hole 122 is penetrated by a shaft 5, and the assembly inner hole 122 and the shaft 5 form an interference fixed connection. In this embodiment, the axial thickness of the oil seal body 1 is 7mm to 8mm, the inner diameter of the sealing lip 121 is 32mm to 35mm, the elastomer 12 is made of nitrile rubber, and grease lubrication is used for lubrication.

[0024] like Figure 4As shown, a hub motor includes a stator 4, a rotor 3, a support cover, a shaft 5, and also includes the oil seal body 1 in the above technical solution. The rotating structure 2 in the above technical solution is the support cover of the hub motor. The support cover is used to refer to the rotating structure 2 for description. The mating surface between the support cover and the sealing lip 121 is a circumferential surface. The rotor 3 is sleeved on the outside of the stator 4 and connected to the shaft 5 through the support cover and the bearing 6. The rotor 3 includes a rim 31, a magnetic ring 32 and a permanent magnet 33. The rim 31 and the magnetic ring 32 are welded and fixed, and the permanent magnet 33 is arranged on the inner circumference of the magnetic ring 32. The stator 4 includes a stator core 41, an enameled wire 42 and a bracket 43. The stator core 41 is made of stacked silicon steel sheets. A sleeve 44 is welded on the bracket 43. The sleeve 44 and the shaft 5 are fixed by interference connection. The outer circumference of the bracket 43 is fixed to the inner circumference of the stator core 41 , and the rotor 3 is fixedly connected to the support cover by screws. The support cover is provided with a bearing 6 , and the inner hole of the bearing 6 is fixedly matched with the shaft 5 .

[0025] Aiming at the structural and size limitation problems of the new national standard wheel hub motor standard parts, the utility model specially develops an oil seal with "inner hole fixed, outer ring rotating seal" structure. On the basis of not increasing the axial opening size, the radial size of the sealing lip is enlarged. Compared with the oil seal with the traditional structure of "outer ring fixed, inner hole rotating seal" used on the existing motor, it breaks the size limitation of the new national standard motor due to the flywheel and other standard parts on the basis of not changing the motor assembly structure and assembly size. The size of the sealing lip is enlarged, and the motor has a larger lead-out wire outlet space, which can increase the number of outlet wires, thereby improving the current overload capacity of the motor. In addition, the grease storage tank provided in the sealing lip of the oil seal can store enough spare grease for a long time to supply the grease loss of the motor during long-term operation, thereby reducing the dry wear of the oil seal lip and the rotating structure, greatly reducing the energy consumption of rotational friction, and the oil seal has small resistance, sufficient lubrication, and long service life.

[0026] The electric vehicle hub motor provided by the utility model is used to drive electric vehicles. Compared with existing electric vehicle motors, it has excellent airtight and waterproof functions, the oil seal is fully lubricated, the rotation seal resistance is small, the motor efficiency is high, and the service life is long, which is particularly suitable for the use scenarios of new national standard motors; the grease storage tank structure of the oil seal of the utility model significantly reduces the wear of the oil seal and extends its service life; the motor of the utility model, the radial size of the sealing lip is larger than the size of the assembly inner hole, provides a larger space for the lead-out wires of the motor, and the square number of the lead-out wires is significantly increased, thereby greatly improving the current overload capacity of the motor; when the oil seal of the motor of the utility model is installed, the direction of the oil seal opening is facing away from the external environment, which greatly optimizes the working environment of the oil seal. Different from the conventional installation method of the oil seal sealing lip facing outward, the motor structure of the utility model effectively avoids the situation where the oil seal sealing lip is eroded by external foreign objects or the natural environment, greatly improves the use environment of the oil seal, delays its light aging, greatly extends the service life of the oil seal, and also extends the waterproof life of the motor.

[0027] The embodiments described above are only preferred embodiments of the present invention, which are only used to illustrate the technical solution of the present invention, and are not intended to limit the patent scope of the present invention. Any modification or equivalent replacement of the technical solution of the present invention using the contents of the present invention specification and drawings, or any direct or indirect application in other related technical fields, are also included in the patent protection scope of the present invention.

[0028] Although the terms such as oil seal body 1, rotating structure 2, rotor 3, stator 4, shaft 5, bearing 6, metal frame 11, elastic body 12, grease storage tank 13, rim 31, magnetic ring 32, permanent magnet 33, stator core 41, enameled wire 42, bracket 43, sleeve 44, sealing lip 121, assembly inner hole 122 are used more frequently in this article, the possibility of using other terms is not excluded. The use of these terms is only for more convenient description and explanation of the essence of the utility model; interpreting them as any additional restrictions is contrary to the spirit of the utility model.

Claims

1. An oil seal for inner hole positioning installation, the oil seal body (1) comprises a metal frame (11) and an elastic body (12), the metal frame (11) is embedded in the elastic body (12), characterized in that: The oil seal body (1) is provided with a sealing lip (121) and an assembly inner hole (122); the sealing lip (121) is a circular structure; the diameter of the sealing lip (121) is greater than the diameter of the assembly inner hole (122); and the difference between the diameter of the sealing lip (121) and the diameter of the assembly inner hole (122) is ≥4 mm.

2. An inner hole positioning and installation oil seal according to claim 1, characterized in that: The oil seal body (1) is located outside the rotating structure (2), and the sealing lip (121) forms a dynamic rotating seal with the matching rotating structure (2).

3. The inner hole positioning and installation oil seal according to claim 1, characterized in that: A shaft (5) is inserted into the assembly inner hole (122), and the assembly inner hole (122) and the shaft (5) are connected in an interference fit manner.

4. The inner hole positioning and installation oil seal according to claim 1, characterized in that: The oil seal body (1) is provided with a grease storage groove (13), and the grease storage groove (13) is located between the sealing lip (121) and the assembly inner hole (122).

5. A hub motor, characterized in that: It comprises an inner hole positioned oil seal as described in any one of claims 2 to 4, and also comprises a support cover, wherein the support cover is the rotating structure (2), the mating surface between the support cover and the sealing lip (121) is a circumferential surface, and the front section of the mating part of the rotating structure (2) is provided with a guide slope.

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