Description:
FIELD OF THE INVENTION:

[0001] The present invention pertains to the field of hub motor assemblies for electric vehicles and also in any vehicle motor with a power cable passage through the shaft. More particularly, the present invention relates to a sealing mechanism designed for a hub motor. The present invention, therefore, addresses the prevention of water seepage at the cable entry point of a hub motor shaft by applying a sealant and enhancing the sealing process with the incorporation of an O-ring.

BACKGROUND:

[0002] Hub motors are electric motors integrated into the wheel hubs of vehicles, typically electric or hybrid vehicles. Instead of relying on a central motor and a complex mechanical drive train, hub motors directly power the wheels. The hub motor comprises an electric motor, usually a brushless DC motor, and a gearbox, all contained within the wheel hub.

[0003] The purpose of hub motors is to provide direct drive power to the wheels, eliminating the need for a separate transmission system. This design offers several advantages, including improved efficiency, better torque control, regenerative braking, and simplified vehicle design. By placing the motor at the wheel, hub motors allow for independent control of each wheel, enabling advanced features like all-wheel drive and torque vectoring.

[0004] To ensure the reliability and performance of hub motors, effective sealing mechanisms or sealants are utilized for contaminant ingress protection, environmental durability, and optimal performance.

[0005] Specifically, water ingress can be a significant concern for hub motors, especially in applications like e-bikes and electric scooters that are frequently exposed to rain or wet conditions. The intrusion of water into the motor housing can lead to corrosion, short circuits, or damage to internal components, resulting in motor failure and reduced performance.
[0006] The power cable assembly plays a vital role in preventing the ingress of contaminants, such as water, air, and dust, into the hub motor assembly. It enables the transmission of electrical power from the power source to the motor. To create a protective barrier, sealants are filled to the hole and power cable entry area of the motor housing or shaft.

[0007] Existing sealing mechanisms in hub motors are currently facing challenges. While a sealant was indeed filled between the shaft and cable, it did not provide complete coverage around the entire circumference of the shaft hole and cable assembly. Moreover, the sealant failed to extend along the entire length of the shaft hole. The fundamental issue leading to this problem was the misalignment of the cable within the shaft hole during the assembly process, causing it to be skewed in one direction. This misalignment, in turn, hindered the sealant from achieving complete omnidirectional coverage along the entire length of the cable. Consequently, water ingress becomes a problem in the hub motor shaft, leading to rust and malfunction of essential components like the hall sensor, leading to product failure in the field.

[0008] To overcome the aforementioned drawbacks, the present invention provides an improved sealing mechanism for hub motor cable assemblies. This mechanism aims to eliminate the gap between the cable and the shaft hole by preventing any skewing of the cable. Additionally, this improved mechanism preventing the sealant from fully encircling the shaft hole for the cable. Instead, a passage of sealant throughout the length of the shaft is ensured facilitating an omnidirectional coverage of the interior walls of the shaft and cable assembly, resulting in effectively eliminating the ingress of water and contaminants.

OBJECTIVES OF THE INVENTION:

[0009] The primary objective of the present invention is to incorporate an O-ring in a hub motor shaft around the hub motor cable in a hub motor assembly.
[0010] Another objective of the present invention is to provide a corresponding O-ring groove on the internal walls of the shaft, to ensure a proper placement of the O-ring within the shaft.
[0011] Yet another objective of the present invention is to create a uniform gap between the cable and shaft to insert a hub motor cable within the shaft which comprises an O-ring, thereby preventing the skewing of the cable within the shaft.
[0012] Yet another objective of the present invention is to achieve a complete omnidirectional coverage of sealant, by applying it through a sealant filling hole present on the shaft
[0013] Further objective of the present invention is to provide for an arrangement wherein the O-ring serves a dual role by preventing the outward flow of the inserted sealant from traversing the O-ring and its associated groove, effectively eliminating the ingress of liquids and contaminants.
[0014] Other objects and advantages of the present invention will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the invention.

SUMMARY

[0015] To achieve the aforementioned objectives, the present invention provides an effective sealing mechanism for hub motor assemblies to cover a shaft and cable assembly completely in all directions so as to eliminate the ingress of liquids and contaminants.

[0016] A sealing arrangement is disclosed for a hub motor assembly (300), featuring a shaft (102) connected to a stator of the hub motor (302). The shaft (102) is equipped with a shaft hole (104) and an O-ring groove (106) on the internal wall of the shaft. An O-ring (108) is inserted into the groove (106) to ensure proper placement. The shaft further comprise a hole/ aperture for sealant filling. Hub motor cable (202) is inserted through the shaft hole (104) within the shaft (102), and a sealant is then added the sealant filling hole (110) in the shaft (102), before curing the filled sealant.

[0017] The O-ring (108) serves to obstruct an outward flow of the sealant filling. The sealant filling that is filled via the sealant hole entirely covers the cable in the added spacing. Moreover, the presence of the O-ring ensures that the filled sealant does not traverse the placed O-ring, as the O-ring plugs the outward movement of the sealant. The arrangement therefore, achieves an omnidirectional coverage of the sealant within the spacing between the shaft (102) and the cable (202). The O-ring (108) may be made of rubber, plastic, or a combination thereof and is positioned in the middle of the total length of the cable groove for complete coverage. The O-ring (108) is round, with an outer diameter falling in the range of 13mm to 16mm or 23mm to 26 mm, while the width of the O-ring groove falls in the range of 3mm to 4mm, and the depth of the O-ring groove falls in the range of 2mm to 3mm.

[0018] In a method for sealing a hub motor assembly (300), a shaft (102) is provided with an O-ring groove (106), and an O-ring (108) is inserted into the groove to establish a seal between the cable (202) and the shaft (102). The O-ring (108) arrests a spacing between the cable (202) and the shaft thereby preventing an outward flow of the sealant. Sealant is filled via the sealant filling hole (110) following established procedures for curing, resulting in an omnidirectional coverage of the sealant within the spacing between the shaft (102) and the cable (202). Furthermore, the method allows for the insertion of the O-ring (108) via any specialized or any customized tools before inserting the cable (202) into the shaft hole (104).

[0019] The arrangement of the present invention has other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following brief description, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be better understood fully from the detailed description that is given herein below with reference to the accompanying drawings of the preferred embodiments of the present invention, which, however should not be deemed to be a limitation to the invention to the specific embodiments, but are for the purpose of explanation and understanding only.

[0021] FIG. 1 illustrates the O-ring, the hub motor cable and a hub motor shaft incorporated with an O-ring, according to the present invention.

[0022] FIG. 2 illustrates the hub motor shaft comprising an O-ring groove and a shaft comprising an O-ring , according to the present invention.

[0023] FIG. 3 illustrates the front and side view of an arrangement of a hub motor according to the present invention.

[0024] FIG. 4 illustrates a sealing mechanism according to the present invention.

[0025] FIG. 5 illustrates the hub motor arrangement before and after filling a sealant, according to the present invention.

REFERENCE NUMERALS
[0026] The list of reference numerals that are used in the accompanying drawings are provided below.

102 –shaft
104 – shaft hole
106 – O-ring groove
108– O-ring
110 – sealant filling hole
112 – sealant
202 – cable
300 – hub motor assembly
302 – hub motor

DETAILED DESCRIPTION OF THE INVENTION

[0027] The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments and drawings in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0028] The present invention discloses an effective sealing arrangement for hub motor assemblies to completely cover the shaft and cable assembly and to eliminate the ingress of liquids and contaminants such as water, liquid or any fluid, air, mud, dust, but not limited to it. The term “O-ring” is a mechanical gasket, typically a loop or ring-shaped, made from elastomer materials such as rubber or silicone. Its design allows it to be compressed between two mating surfaces to create a seal.

[0029] The introduction of an O-ring around the cable in this invention serves to eliminate the gap between the hub motor cable and hub motor shaft by preventing cable skewing. Moreover, the O-ring acts as a barrier, blocking the passage of sealant, ensuring effective a complete sealing around the shaft hole for the cable. In essence, the combination of O-ring sealing and sealant application results in a comprehensive and effective sealing solution.

[0030] The hub motor further experienced water ingress problems, leading to rust and product failure in the field. Despite the application of sealant between the shaft and cable, it failed to provide complete omnidirectional coverage around the shaft hole and cable assembly, extending the entire length of the hole. The core issue stemmed from the cable getting misaligned inside the shaft hole during assembly, hindering the sealant from achieving full complete coverage along the cable's length.

[0031] To address this, the concept involves incorporating an O-ring around the hub motor cable and a corresponding O-ring groove in the shaft. This arrangement aims to eliminate any gaps between the cable and shaft hole, with the O-ring also serving to obstruct the passage of sealant. This ensures that the sealant achieves comprehensive complete coverage without crossing the O-ring and its groove, resolving the water ingress problem.

[0032] Fig1 discloses an O-ring (108), hub motor cable (202) and a hub motor shaft (102) incorporated with the O-ring (108) according to the present invention. As stated, this involves placing an O-ring (108) within an O-ring groove (106) in the shaft, encircling the hub motor cable (202) to enhance the sealing beyond what the sealant provides. The O-ring (108) serves to eliminate any gap between the cable (202) and the shaft (102). This obstruction is established as the O-ring (108) makes contact with the cable and the shaft, acting as a barrier to prevent the sealant (112) from traversing the O-ring to the other end and further, ensuring complete comprehensive coverage.

[0033] Referring to Fig.2(a), the shaft (102) of the hub motor is incorporated with the cable (202) and grooves for the placement of O-ring (108), hole for sealant filling (110), and groove for the cable i.e the shaft hole (104) is disclosed. According to the present invention, the effective sealing arrangement for a hub motor assembly (300) comprises a shaft (102) as shown in Fig 2(b). The shaft further comprises an O-ring (108) which is then set to receive a cable (202) and a sealant hole (110) to seal the portion of the cable by applying sealant via the sealant hole as seen in Fig.2(b).

[0034] Figs. 2a & 2b further illustrate the shaft assembly along with the hub motor cable and shaft. The O-ring (108) mounted on the groove (106) seals and hold the cable (202), mounted within the shaft (102) in position without skewing, but also results in providing a uniform gap between the cable and the shaft (102). The sealant hole (110) is used for applying sealant (112) inside the shaft (102). The sealant (112) covers the sealant filled area of the cable, but is not allowed to traverse the O-ring throughout the shaft length. Moreover, it prevents the ingress of liquids and contaminants into the hub motor.

[0035] In Fig. 3, the depiction showcases the hub motor along with the shaft and cable assembly as per the current invention. According to Fig.3, the figures provide a representation of the hub motor assembly (300), including the shaft (102) and cable (202). Additionally, the O-ring (108) situated within the hub motor's shaft is featured in this figure. The inclusion of the O-ring (108) serves to hinder the outward movement of the filled sealant. It also maintains the alignment of the cable, preventing any skewing within the shaft of the hub motor assembly. Moreover, it acts as a barrier to prevent the entry of water, liquids, or contaminants into the hub motor shaft assembly. Furthermore, Fig.4 further illustrates the arrangement for the sealing of the hub motor assembly according to the present invention.

[0036] ¬It is important to highlight that the provision of the O-ring (108) in a proper O-ring groove effectively closes the gap, preventing the entry of contaminants into the hub motor assembly. When inserting a cable (202) through the shaft (102) equipped with the O-ring (108), the O-ring holds the cable firmly in position without chances of skewing. The O-ring further acts as a seal acting as a barrier to contaminants and fluids. Moreover, the O-ring prevents the movement of a sealant that is filled via the sealant hole. Instead, complete coverage of the filled sealant is achieved as a consistent gap facilitated by the O-ring (108), is established between the cable (202) and the shaft (102).

[0037] In Fig. 4, the shaft (102) is designed to accommodate a cable (202). The shaft (102) is initially crafted with a groove (106) for the O-ring (108), strategically placed in an appropriate location along the cable passage area. Following this, the O-ring (108) is carefully inserted into the groove (106) of the hub motor shaft (102), ensuring a secure placement within the designated groove on the shaft, before introducing the cable (202). Next step emphasizes that the O-ring (108) acts as a barrier, preventing or sealing any gap that may exist between the cable (202) and the shaft (102). This process effectively safeguards against the infiltration of liquids and contaminants into the hub motor shaft assembly, as further depicted in Figs. 5 (a) and (b). Notably, the sealant application through the sealant filling hole (110) maintains a uniform spread without traversing the O-ring, as illustrated in Fig. 5(b).

[0038] FIG. 6 illustrates the process flow depicting the operation of the sealing mechanism in the hub motor arrangement. According to the present invention, a method for effectively sealing a hub motor assembly comprises a shaft (102) for receiving a cable (202) and is equipped with an O-ring groove designed for the precise placement of an O-ring. Subsequently, the O-ring (108) is inserted into the groove of the shaft ensuring its proper positioning

[0039] Moving on, the cable (202) is introduced into the shaft hole (104), allowing the O-ring (108) to establish a seal between the cable and the shaft. The next step emphasizes the O-ring within the cable acting as a barrier, preventing or sealing any gap that may exist between the cable and the shaft hole as seen in Fig.5(a)

[0040] The sealant (112) is then filled via the sealant hole (110) within the shaft, and conventional procedures are followed to cure the sealant. In the presence of the O-ring make sure that the sealant filling does not cross over /traverse the seal barrier set by the O-ring. As a result, in the final step, the sealant provides comprehensive coverage, spanning spherically on one end of the shaft hole or cable insertion area. Once the sealant filling is cured, dual protection from the O-ring as well as the sealant is established ensuring effective sealing and protection in the hub motor assembly.

[0041] Therefore, the O-ring effectively eliminates or closes any gap between the cable and the shaft. This obstruction is established by the O-ring making contact with the cable, serving as a barrier to prevent the sealant filling from moving to the opposite end. Consequently, the O-ring functions as a blockage, ensuring the sealant covers a complete circular coverage without spreading to the other end, before being cured.

[0042] The O-ring, is typically composed of materials like rubber or plastic, and an O-ring groove is embedded inside the shaft. The insertion of the O-ring into the shaft's groove can be accomplished using any specialized or customized tool. A strategically placed O-ring groove, preferably in the middle of the total cable groove length or another suitable area, facilitates a seamless omnidirectional flow of sealant. The preferred structural shape for the O-ring is round.

[0043] Additionally, the specifications for the O-ring, without limiting the scope of the invention, include an outer diameter ranging from 13mm to 16mm or 23mm to 26mm, an inner diameter ranging from 8mm to 10mm or 15mm to 20mm, and a cross-section diameter ranging from 2mm to 3mm. Concerning the O-ring groove within the shaft, the preferred width is between 3mm and 4mm, with a depth ranging from 2mm to 3mm. The main procedural step involves placing the O-ring into the designated groove within the shaft and subsequently inserting the cable into the shaft hole. This ensures the effective elimination of any existing gap between the cable and the cable shaft hole, preventing cable skewing post-insertion.

[0044] The present invention introduces several advantages. Firstly, the incorporation of an O-ring in the designated groove ensures a comprehensive seal, effectively covering any gaps and enveloping the cable and one end of the shaft hole or cable insertion area in an omnidirectional sealant. Additionally, the O-ring functions to obstruct any gaps, preventing the sealant from reaching the opposite end of the shaft hole. This innovation facilitates an efficient seal between the cable and shaft through the utilization of the O-ring in the cable.

[0045] Moreover, the implementation of this solution is not only easy but also cost-effective. Its seamless integration allows for immediate application without the need for additional testing, infrastructure, manpower, or specialized skill sets. The solution leverages readily available elements in the market, eliminating the necessity for additional manufacturing processes. In essence, this inventive approach presents a practical and economical solution to sealing challenges.

[0046] While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above-described embodiment, method, and examples, but by all embodiments and methods within the scope of the invention as claimed.
, Claims:WE CLAIM:

1. A sealing arrangement for a hub motor assembly (300), wherein the arrangement comprises:
a shaft (102) having a shaft hole (104) for receiving a cable (202); and
the cable (202) inserted through the shaft hole (104) of the shaft (102);
the said shaft (102) connected to a stator of the hub motor (302);
wherein
the shaft (102) comprises
an O-ring groove (106) for positioning an O-ring (108) on an internal wall of the shaft (102); and
a sealant filling hole (110) for sealant filling (112).

2. The sealing arrangement as claimed in claim 1, wherein the filled sealant (112) omnidirectionally covers an area of the cable.
3. The sealing arrangement as claimed in claim 1, wherein the positioned O-ring (108) seals the sealant (112) and obstructs an outward flow of the said filling.
4. The sealing arrangement as claimed in claim 1, wherein the filled sealant (112) is cured post filling.
5. The sealing arrangement as claimed in claim 1, wherein the O-ring (108) is made of rubber, plastic, or a combination of the same thereof.
6. The sealing arrangement as claimed in claim 1 wherein the outer diameter of the O-ring (108) falls in the range of 13mm to 16mm diameter or 23mm to 26 mm diameter.
7. The sealing arrangement as claimed in claim 1 wherein the width of the O-ring groove (106) falls in the range of 3mm to 4mm and the depth of the O-ring groove falls in the range of 2mm to 3mm.
8. A method for a sealing arrangement in a hub motor assembly (300), the method comprising steps of:
a. providing a shaft (102) having a shaft hole (104) configured for receiving a cable (202), with an O-ring groove (106) positioned on an internal wall of the shaft;
b. placing an O-ring (108) within the O-ring groove (106) provided on the internal wall of the shaft;
c. inserting a cable into the shaft hole (104), such that the O-ring (108) establishes a tight seal between the cable and the shaft;
d. filling a sealant (112) via a sealant filling hole (110) to obtain a sealant filled area; and
e. curing the filled sealant (112);
wherein
an omnidirectional coverage of the sealant (112) is achieved, and
the O-ring (108) placed in the groove seals the shaft and the cable preventing an outward flow of the sealant.

9. The method for a sealing arrangement as claimed in claim 8, wherein inserting an O-ring (108) may be done via tools.

Dated this the 24th Day of February 2024