Claims:We claim:
1. A hub motor assembly (100) for a vehicle, comprising a stator (108) mounted to a shaft (114), a rotor (104) mounted to a wheel rim (102) and coupled to said shaft (114) through at least one bearing unit (122), and a cable harness (112) to supply electric power from a power source to said stator (108), characterized in that:
an opening (110) in said at least one bearing unit (122) to route said cable harness (112) to said stator (108).

2. The hub motor assembly (100) as claimed in claim 1, wherein said opening (110) is made in an inner race (116) of said bearing unit (122).

3. The hub motor assembly (100) as claimed in claim 1, wherein said opening (110) is made in a sleeve (302) in contact with an inner race (116) of said bearing unit (122), and wherein said sleeve (302) is located between said inner race (116) and said shaft (114).

4. The hub motor assembly (100) as claimed in claim 1, wherein said opening (110) is made at the interface of an inner race (116) and an a sleeve (302) of said bearing unit (122) in a manner, that said opening (110) is partially in said inner race (116) and partially in said sleeve (302), and wherein said sleeve (302) is located between said inner race (116) and said shaft (114).

5. The hub motor assembly (100) as claimed in claim 1, wherein said opening is a through bore.

6. The hub motor assembly (100) as claimed in claim 5, wherein said through bore is at least one of a skewed, parallel and curved with respect to a central axis of said bearing unit (122).

7. The hub motor assembly (100) as claimed in claim 1, wherein said vehicle is any one of a motorcycle, a scooter, a car an auto-rickshaw and the like.

8. A bearing unit (122) for a wheel shaft (114) of a vehicle, comprising an inner race (116), an outer race (120), and plurality of bearings (118) between said inner race (116) and said outer race (120), characterized in that,
an opening (110) provided in any one of said inner race (116) and said outer race (120) for the passage of a cable harness (112).

9. The bearing unit (122) as claimed in claim 8, wherein said opening (110) is a through bore.

10. The bearing unit (122) as claimed in claim 9, wherein said through bore is at least one of a skewed, parallel and curved with respect to a central axis of said bearing unit (122).
, Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:

Field of the invention:
[0001] The present invention relates to a hub motor assembly for a vehicle.

Background of the invention:
[0002] According to a patent literature US 2012/0065825, an electric front wheel drive system for motorcycle is provided. A two-wheel drive motorcycle having a motor-generator driving the front wheel, an embodiment of the present invention, in addition to and independent of a conventional rear wheel drive train. The front wheel drive disclosed herein may be adapted to a conventional motorcycle front wheel and telescoping (or shock-absorbing) front fork suspension systems. The front wheel drive of the two-wheel drive motorcycle may be applied to a number of different types of motorcycles including motocross, enduro, dual-sport and touring motorcycles.

Brief description of the accompanying drawings:
[0003] An embodiment of the disclosure is described with reference to the following accompanying drawing,
[0004] Fig. 1 illustrates a cut-section view of a first hub motor assembly, according to an embodiment of the present invention;
[0005] Fig. 2 illustrates different views of first bearing unit, according to an embodiment of the present invention;
[0006] Fig. 3 illustrates the cut-section view of a second hub motor assembly, according to an embodiment of the present invention, and
[0007] Fig. 4 illustrates different views of the second bearing unit, according to an embodiment of the present invention.

Detailed description of the embodiments:
[0008] Fig. 1 illustrates a cut-section view of a first hub motor assembly, according to an embodiment of the present invention. The hub motor assembly 100 for a vehicle, comprises a stator 108 mounted to a shaft 114, a rotor 104 mounted to a wheel rim 102 and coupled to the shaft 114 through at least one bearing unit 122, and a cable harness 112 to supply electric power from a power source (not shown) to the stator 108. The hub motor assembly 100 is characterized by an opening 110 in the at least one bearing unit 122 to route the cable harness 112 to the stator 108. The opening 110 is made in an inner race 116 of the bearing unit 122. The opening 110 is a hole or a slot (of any dimension suitable for a cable entry of different sizes) made in the bearing unit 122. A pair of covers 106 are fixed on either sides of the wheel rim 102. The covers 106 rest on the bearing unit 122. It is understood that another bearing unit is either the same bearing unit 122 or a separate bearing unit without any opening 110. Another bearing unit is provided for the other side of the shaft 114.

[0009] In accordance to an embodiment of the present invention, the hub motor 100 comprises two bearing units 122 one each for each side or the side covers 106. The opening 110 is provided in both the two bearing units 122. The cable harness 112 is routed through the opening 110 of both the bearing units 122.

[0010] Fig. 2 illustrates different views of a first bearing unit, according to an embodiment of the present invention. The bearing unit 122 shown in Fig. 1 and Fig. 2 is referred to as a first bearing unit 122. A numeral 210 illustrates a front view of the first bearing unit 122. A numeral 220 illustrates a side cross-section view of the first bearing unit 122. A numeral 230 illustrates a perspective view of the first bearing unit 122. The width or the thickness of the inner race 116 and the outer race 120 is dissimilar, i.e. the width of the inner race 116 is larger than the width/thickness of the outer race 120 to accommodate the opening 110. The bearing 118 used is either a roller bearing or a ball bearing or any other type of bearing which could take radial loading and axial loading.

[0011] Fig. 3 illustrates the cut-section view of a second hub motor assembly, according to an embodiment of the present invention. The second hub motor assembly 100 is same as the first hub motor assembly 100, but the opening 110 is made in a sleeve 302 other than the inner race 116 of the bearing unit 122. The sleeve 302 is located between the inner race 116 and the shaft 114. The bearing unit 122 illustrated in Fig. 3 and Fig. 4 is referred to as a second bearing unit 122. The sleeve 302 is mounted in contact with the inner race 116. The inner race 116 of the second bearing unit 122 is thinner as compared to Fig. 1 and Fig. 2 i.e. the dimensions of the inner race 116 is of a standard type (which are available in market for a respective type of vehicle) i.e. no custom bearing is required, as in the case of the first bearing unit 122 in the Fig 1. The sleeve 302 is press fit to the inner race 116 of the bearing unit 122 and the sub-assembly of the second bearing unit 122 with sleeve 302 is fitted on the shaft 114. In fig. 1, the sleeve 302 and the inner race 116 are provided as an integrated or single part.

[0012] In accordance to an embodiment of the present invention, the opening 110 is made at the interface of the inner race 116 and the sleeve 302 of the bearing unit 122. The opening 110 is made in a manner that the opening 110 is partially in the inner race 116 and partially in the sleeve 302. The sleeve 302 is located between the inner race 116 and the shaft 114.

[0013] Fig. 4 illustrates different views of a second bearing unit, according to an embodiment of the present invention. A numeral 410 illustrates a front view of the second bearing unit 122. A numeral 420 illustrates side cross-section view of the second bearing unit 122. A numeral 430 illustrates perspective view of the second bearing unit 122. The second bearing unit 122 is similar to the first bearing unit 122, except the addition of the sleeve 302.

[0014] In accordance to an embodiment of the present invention, the vehicle is any one of a motorcycle, a scooter, a car, an auto-rickshaw and the like, or wherever the hub motor is used. The rotor 104 of the hub motor assembly 100 comprises plurality of permanent magnets arranged around an inner surface of the wheel rim 102. The stator 108 comprises excitation coils (not shown) and connected with the power source (not shown). The power source is at least one of a battery, an electrical generator, a fuel cell and the like.

[0015] In accordance to another embodiment of the present invention, the opening 110 is a through bore. The axis of the through bore is any one of a skewed, parallel and curved with respect to a central axis of rotation of the bearing unit 122.

[0016] In accordance to an embodiment of the present invention, the bearing unit 122 for a wheel shaft 114 of the vehicle is provided. The bearing unit 122 comprises the inner race 116, an outer race 120, and plurality of bearings 118 between the inner race 116 and the outer race 120. The bearing unit 122 is characterized by, an opening 110 provided in any one the inner race 116 and the outer race 120 for the passage of a cable harness 112. If the inner race 116 is stationary, then the opening 110 is provided in the inner race 116. Similarly, if the outer race 120 is stationary, then the opening 110 is provided in the outer race 120.

[0017] The opening 110 is a through bore. The opening 110 is at least one of a skewed, parallel and curved with respect to a central axis of rotation of the bearing unit 122. Further, the bearing unit 122 is provided for a shaft 114 of a hub motor assembly 100.

[0018] In accordance to an embodiment of the present invention, the hub motor assembly 100 allows a solid shaft to be used without any holes or slots therein, thereby improving the strength and durability of the shaft 114. Manufacturing of such hub motor assembly 100 is easy and simple. Ease in assembling and routing the cable harness 112. Possibility of damage to the cable harness 112 is negligible as there are no sharp edges at the entry and exit of the opening 110.

[0019] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.