(SECTION 10 and Rule 13)

Title of the Invention:

A rim in a wheel assembly for mounting a tire

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]This invention relates to a rim in a wheel assembly for mounting a tire and a method thereof.

Background of the invention

[0002] It is known to install an electric motor as wheel hub motor in the interior room of a rim. The wheel hub motor has an electric motor with a rotor and a stator, in which the rotor interacts with the stator to produce a motor torque. The rotor is arranged to be rotatable about a main axis of rotation relative to the stator. The stator is arranged rotationally-secured to the vehicle. In contract, the rotor is connected with a wheel in a rotationally secured manner. As known, the rotor and the wheel overlap in radial direction to the main axis of rotation. The wheel is directly connected to the rotor. Existing In-Wheel hub motor configuration has a steel rim, which undergoes a shape bend for higher loads, or loads marginally equal to wheel design load because of their process limitation and increased load requirements. Existing Motor construction will allow water to enter through the miniature gap between both side covers and rim.

[0003] A prior art DE patent application DE3611038 discloses a wheel unit for the tires of motor vehicles. The wheel unit comprises a one-piece cast or forged light alloy wheel with a wheel disc provided with a central hub part and with a rim supporting the tire. The wheel unit also comprises a covering plate, which can be attached non-positively and/or positively to the outside of the wheel disc. This covering plate virtually covers the entire wheel disc. In contrast, the wheel disc positioned independently of the covering plate is designed to reduce weight with sufficient static strength and is mainly composed of individual, radially oriented struts, which connect the central hub part to the rim.

Brief description of the accompanying drawing

[0004] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

[0005] FIG. 1 illustrates a wheel assembly unit in a vehicle in accordance to one embodiment of the invention.

Detailed description of the embodiments

[0006]FIG. 1 illustrates a wheel assembly unit in a vehicle in accordance to one embodiment of the present invention. The wheel assembly 10 comprises a hub motor unit 12 having at least two magnets 14. The wheel assembly 10 further comprises a shaft 16 passing through the hub motor unit 12. The rim 11 is mounted above the hub motor unit 12. The rim 11 is made of a first component 18 and a second component 20, wherein the first component 18 has integrated supporting elements 22. [0007]Further, the construction of the wheel assembly and the components along with their working is explained as follows. The hub motor unit 12 comprises motor windings positioned below the two magnets 14. The two magnets 14 of the motor are placed parallel to each other. The hub motor unit 12 comprises an opening (not shown) to accommodate the shaft 16 of the vehicle. The rim 11 comprising the first component 18 and the second component 20 is mounted on the hub motor unit 12 in the wheel assembly 11. The first component 18 of the rim 11 comprises a hole (not shown) corresponding to the opening of the hub motor unit 12 for accommodating the shaft 16 of the vehicle. The rim 11 is mounted on the shaft 11 by at least one bearing element 29.

[0008]The first component 18 of the rim 11 comprises multiple cut-sections corresponding to multiple cut-sections of the hub motor unit 12, such that, the first component 18 seals one side of the hub motor unit 12, when fitted on said one side of the hub motor unit 12. According to one embodiment of the invention, the first component 18 is fitted on to an internal side of the wheel assembly 10 that faces the inside of the vehicle and the second component 20 is fitted on an external side of the wheel assembly 10 that faces the outer atmosphere.

[0009] The first component 18 has the uniform profile thickness, which helps in sealing the internal side of the wheel assembly 10 effectively. The first component 18 and the second component 20 of the rim 11 is fitted onto the hub-motor unit 12 using at least one fitting technique. The fitting techniques are chosen from a group of fitting techniques comprising a press fit, a screw fit, a fastener and the like.

According to one embodiment of the invention, the first component 18 is press fitted onto the inner side of the hub motor unit 12 and the second component 20 is screw fitted on to the outer side of the hub motor unit 12.

[0010]The supporting elements 22 are integrated into the first component 18 of the rim 11 during the manufacturing process. The supporting elements 22 are made of a material chosen from a group of materials comprising iron, steel and the like. According to one embodiment of the invention, the first component 18 has two supporting elements 22 placed in a position corresponding to the two magnets 14 of the hub motor unit 12. When the first component 18 of the rim 11 is mounted on the hub motor unit 12 and the shaft 16, and the two supporting elements 22 encounters with corresponding two magnets 14 of the hub motor unit 12. However, it is to be understood that, the material of the supporting element 22 is not restricted to the above-mentioned materials, but can be any other material, which is compatible for generating a magnetic field when encountered with the magnet 14 as known to a person skilled in the art.

[0011]The first component 18 comprises a tire mounting area 30 for accommodating a tire of the vehicle. The mounting area 30 on the first component 18 is made in such a way that, a standard size of the tire can be easily placed in the mounting area 30. However, it is to be understood that, the dimensions of the mounting area 30 of the rim 11 can be altered according to the tire dimensions.

[0012]The second component 20 of the rim 11 is detachably fitted onto an other side of the hub motor unit 12. According to one embodiment of the invention, the second component 20 is detachably fitted onto an external side of the hub motor unit 12.

The shaft 16 is made to pass through the first component 18 of the rim 11 and the hub motor unit 12 until the second component 20.

[0013]The second component 20 comprises multiple fins 32 made on an outer surface. The multiple fins 32 present on the outer surface of the second component 20 acts as a heat- dissipating element. The multiple fins 32 represents the struts of the wheel assembly. A braking pad 35 is connected to the outer surface of the second component 20. The second component 20 is fitted to the hub motor unit 12 using the screw fit technique. A plurality of screws 36 are used to fit the second component to the hub motor unit 12. The second component 20 is made detachable such that, the repair and the replacement of the motor unit 12 can be done without much hassle. According to one embodiment of the invention, the rim 11 is made of aluminum material.

[0014]A method of working of the wheel assembly 10 in a vehicle is explained as follows. According to one embodiment of the invention, the vehicle is an electric vehicle. The motor unit is mounted in the hub 12 of the wheel assembly 10 and the rim 11 is mounted above the hub motor unit 12, such that, the supporting elements 22 comes into contact with the magnets 14 of the motor. The shaft 16 is made to pass through the hub motor unit 12 and the rim 11. During the working condition of the vehicle, the shaft 16 acts as a stator/stationary element and the rim 11 along with the hub motor unit 12 acts as a rotating element/rotor. The supporting elements 22 are attracted to the magnets 14 of the motor during this process. When the stator (shaft) 16 is supplied with the current, the rotor (the rim 11 and the hub motor unit 12) starts rotating. Due to the movement of the magnets 14 and the corresponding supporting elements 22, a magnetic field is generated. The rotation of the magnets 14 along with the rim 11 rotates the tire of the vehicle.

[0015]With the above-disclosed rim 11, the entry of the foreign materials like water/dirt particles is prevented as the rim 11 seals the hub motor unit 12. The new design of the rim 11 does not require a separate cover to close the hub motor unit 12, thereby the screws used to fasten the cover is not needed during assembly of motor unit 12. The rotating part of the motor is directly precast to the assimilated rim 11. The rotor/rotating part being precast to rim 11 eliminates a welding process required between the parts. The reliability of the rim 11 increases because of increased in strength and quality of rotor sizing is improved.

[0016]The vibrations are minimized because of precast of rim 11 onto the hub motor unit 12. During assembly of motor, the tangential benefit of achieving more precise orientation (concentricity) of parts on the shaft 16 is improved compared to the conventional design. As the rim 11 is made as a single element, it will be easy for motor assembly 12, it will be easy for servicing and repair / replacement of the motor parts. The assembly efforts are reduced as the cycle time of the motor assembly 12 is reduced. In addition to that, an existing ICE vehicle with drum brake system can be retained with an integrated motor cover with drum housing for converting to an electric Vehicle. Optimizable rim width and diameter for the motor is possible with very less changes to the new design of the rim.

[0017] 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.