Patent Description:
Bicycles were prevalent in many places. With the changes in lifestyles, the environmental awareness and the concept of physical fitness, bicycles are popularly used in daily lives. With development of technology, electric bicycles have been a booming trend, especially in cities. The electric bicycles can be roughly classified into types with hub motor and mid-mounted motor. The advantages of the type with hub motor are that it is compact and artistic in appearance, that the appearance of the bicycle is concise, that the price is low, that there is relatively lower level of requirement for the bicycle frame, and that there is relatively lower requirement for the chain, so the electric bicycles are popular around the world. <CIT>, <CIT> and <CIT> disclose the like electric bicycles. An electric bicycle according to the preamble of claim <NUM> is known from <CIT>.

However, the above-mentioned wheel hub motor has a complicated structure, many parts and components are interconnected, and it is difficult and time-consuming to dismantle and replace. Therefore, it needs a repairer who knows specific model of the wheel hub motor well to repair and/or replace the parts and components, which is inconvenient.

The present invention is, therefore, arisen to obviate or at least mitigate the above-mentioned disadvantages.

The main object of the present invention is to provide an electric wheel hub which can greatly simplify the difficulty of maintenance and/or replacement.

To achieve the above and other objects, an electric wheel hub is provided, including: a shell; a motor assembly, including a stator, a rotor and a shaft, the stator and the rotor being received in the shell and relatively rotatable, the rotor being connected and rotatable with the shell, the shaft defining an axial direction and a circumferential direction, the shaft being movable in the axial direction and disposed through the stator, the shaft and the stator being relatively non-rotatable in the circumferential direction; and a battery unit, received in the shell, electrically connected with the motor assembly.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment(s) in accordance with the present invention.

a preferable embodiment of the present invention.

Please refer to <FIG> for a preferable embodiment of the present invention. An electric wheel hub of the present invention includes a shell <NUM>, a motor assembly <NUM> and a battery unit <NUM>.

The motor assembly <NUM> includes a stator <NUM>, a rotor <NUM> and a shaft <NUM>, the stator <NUM> and the rotor <NUM> are received in the shell <NUM> and relatively rotatable, and the rotor <NUM> is connected and rotatable with the shell <NUM>. The shaft <NUM> defines an axial direction <NUM> and a circumferential direction <NUM>, the shaft <NUM> is movable in the axial direction <NUM> and disposed through the stator <NUM>, and the shaft <NUM> and the stator <NUM> are relatively non-rotatable in the circumferential direction <NUM>. The battery unit <NUM> is received in the shell <NUM> and electrically connected with the motor assembly <NUM>. The shaft <NUM> is detachably connected with the stator <NUM> so that the wheel hub can be quickly detached or installed without dismantling parts in the motor assembly <NUM>, which is easy to uninstall/install and lowers the repairing cost.

Specifically, the electric wheel hub further includes a first bearing <NUM> and a second bearing <NUM>, the shell <NUM> includes a base <NUM> and a cover <NUM>, and the cover <NUM> is detachably covered to the base <NUM>. The cover <NUM> includes a first through hole <NUM>, the base <NUM> includes a second through hole <NUM>, the first bearing <NUM> is received in the first through hole <NUM>, the second bearing <NUM> is received in the second through hole <NUM>, and the shaft <NUM> is disposed through the first bearing <NUM> and the second bearing <NUM> and protrusive out beyond opposing sides of the shell <NUM>. Since the shaft <NUM> is detachably connected to the stator <NUM>, the first bearing <NUM> and the second bearing <NUM> do not have to be detached as the shaft <NUM> is removed, which avoids loss of the first bearing <NUM> and the second bearing <NUM>, and simplifies the detachment process. To replace the first bearing <NUM> or the second bearing <NUM>, the motor assembly <NUM> does not have to be detached, which is easy and convenient.

Specifically, the shaft <NUM> further includes a first end portion <NUM>, a connection portion <NUM>, a flange <NUM> and a second end portion <NUM> in sequence. The first end portion <NUM> is disposed through the first bearing <NUM> and the cover <NUM>, the second end portion <NUM> is disposed through the second bearing <NUM> and the base <NUM>, and the connection portion <NUM> is connected with the stator <NUM>. An intersection of the connection portion <NUM> and the first end portion <NUM> includes a stepped portion <NUM>, the first bearing <NUM> is abutted against the cover <NUM> and the stepped portion <NUM> in the axial direction <NUM>, and the second bearing <NUM> is abutted between the base <NUM> and the flange <NUM> between so as to improve stability of the first bearing <NUM> and the second bearing <NUM>.

The shaft <NUM> further includes an axle <NUM> and a plurality of first engaging portions <NUM>, and the plurality of first engaging portions <NUM> are separately arranged on the axle <NUM> in the circumferential direction <NUM>. The axle <NUM> includes the first end portion <NUM>, the connection portion <NUM>, the flange <NUM> and the second end portion <NUM>, the connection portion <NUM> includes the plurality of first engaging portions <NUM>, and the stator <NUM> includes a perforation <NUM> and a plurality of second engaging portions <NUM>. The plurality of second engaging portions <NUM> are separately arranged around the perforation <NUM> in the circumferential direction <NUM>. The axle <NUM> is disposed through the perforation <NUM>. The plurality of first engaging portions <NUM> and the plurality of second engaging portions <NUM> are engaged with each other so that the shaft <NUM> is detachable from the stator <NUM>. One of each said first engaging portion <NUM> and the second engaging portion <NUM> is a first groove, and the other of each said first engaging portion <NUM> and the second engaging portion <NUM> is a first rib. For example, each said first engaging portion <NUM> is a first rib, and each said second engaging portion <NUM> is a first groove.

Preferably, the shaft <NUM> further includes a third engaging portion <NUM>, the stator <NUM> further includes a fourth engaging portion <NUM>, and the third engaging portion <NUM> and the fourth engaging portion <NUM> are engaged with each other. One of the third engaging portion <NUM> and the fourth engaging portion <NUM> is a second groove, and the other of the third engaging portion <NUM> and the fourth engaging portion <NUM> is a second rib, so that the shaft <NUM> and the stator <NUM> can be easily and accurately assembled. The second groove is not identical to the first groove, and the second rib is not identical to the first rib.

The battery unit <NUM> includes a cartridge <NUM> and a plurality of batteries <NUM>, and the plurality of batteries <NUM> are positionally received within the cartridge <NUM> so that it is easy to install and maintain and is stable. In other embodiments, the battery unit <NUM> may be provided without the cartridge <NUM>. The cartridge <NUM> is preferably made of plastic material (such as ABS-PC material) which is of good insulation.

In this embodiment, the cartridge <NUM> is annular, the cartridge <NUM> is disposed around the motor assembly <NUM>, and the plurality of batteries <NUM> are separately disposed around the motor assembly <NUM>. Specifically, the motor assembly <NUM> is inserted to a central portion of the cartridge <NUM>, and the cartridge <NUM> is connected with the stator <NUM> and is not connected with the shell <NUM>, so that the cartridge <NUM> is non-rotatable for providing good stability of the plurality of batteries <NUM>.

Specifically, the stator <NUM> includes a frame <NUM> and a winding coil set <NUM>, the winding coil set <NUM> is wound around the frame <NUM>, the shaft <NUM> is disposed through the frame <NUM>, the frame <NUM> includes the perforation <NUM>, the plurality of second engaging portions <NUM> and the fourth engaging portion <NUM>, and the cartridge <NUM> is connected with the frame <NUM>. As a result, to replace the battery unit <NUM>, it needs only to withdraw the shaft <NUM> and open the cover <NUM>, and the battery unit <NUM> can be easily replaced without dismantling parts inside the motor assembly <NUM> and without dismantling the first bearing <NUM> and the second bearing <NUM>.

Preferably, inner walls of the cartridge <NUM> and the shell <NUM> define at least one insertion portion <NUM> therebetween, and the at least one insertion portion <NUM> is configured for easy detachment of the cartridge <NUM> from the shell <NUM>. In this embodiment, the at least one insertion portion includes a plurality of insertion portions <NUM>, an outer circumferential wall of the cartridge <NUM> includes a plurality of openings <NUM>, the plurality of batteries <NUM> are partially exposed from the opening <NUM>, and the plurality of openings <NUM> and the inner wall of the shell <NUM> form the plurality of the insertion portion <NUM>. The plurality of batteries <NUM> can be observed from the plurality of openings <NUM>, which helps to evaluate conditions of the plurality of batteries <NUM>.

The electric wheel hub further includes two end caps <NUM> configured to be respectively connected to two fork arms <NUM>, the two end caps <NUM> are detachably disposed respectively around opposing ends of the shaft <NUM>, and the shaft <NUM> is hollow and configured for a spindle <NUM> to be disposed therethrough. The shaft <NUM> which is hollow can lower the weight and increase compatibility for the spindle <NUM>. For example, various types of end caps can be used to receive various types of the spindles (having respective diameters of <NUM>, <NUM> and <NUM>, for example).

Preferably, each of the opposing ends of the shaft <NUM> includes a first positioning portion <NUM>, each of the two end caps <NUM> includes a second positioning portion <NUM>, and the second positioning portion <NUM> and the first positioning portion <NUM> are engaged with each other so as to provide stable and accurate combination of the two end caps <NUM> and the shaft <NUM>. One of the first positioning portion <NUM> and the second positioning portion <NUM> is a projection, and the other of the first positioning portion <NUM> and the second positioning portion <NUM> is a recess.

In this embodiment, each said third engaging portion <NUM> is one said second rib, and each said fourth engaging portion <NUM> is one said second groove. In the circumferential direction <NUM>, the second rib has a length more than <NUM> times a length of the first rib, which further enhances the structural strength of the combination.

An electronic control unit <NUM> is disposed on the base <NUM>, and the electronic control unit <NUM> is positioned to the second end portion <NUM> and abutted against the flange <NUM>. The electronic control unit <NUM> is movable with the shaft <NUM> in the axial direction <NUM>, so that the electronic control unit <NUM> can be individually replaced without dismantling the shell <NUM>. The flange <NUM> includes a penetration hole <NUM> extending in the axial direction <NUM>, and the penetration hole <NUM> is configured for arranged wires to electrically connect the electronic control unit <NUM> outside the shell <NUM> and the motor assembly <NUM> inside the shell <NUM>. A side of the flange <NUM> facing toward the second through hole <NUM> includes a first annular member <NUM>, and a side of the flange <NUM> facing toward the electronic control unit <NUM> includes a second annular member <NUM>. The first annular member <NUM> prevents dust and/or mist form coming into the shell <NUM>, and the second annular member <NUM> improves stability of the combination of the electronic control unit <NUM> and the shaft <NUM> and provides good buffering and shock-absorption.

In sum, in the design of the electric wheel hub, the maintenance and/or
replacement frequency and difficulty of different components are taken into account, which allows the maintenance and/or replacement to be carried out without dismantling the motor assembly. As a result, it can greatly simplify the difficulty of maintenance and/or replacement.

Claim 1:
An electric wheel hub, including:
a shell (<NUM>);
a motor assembly (<NUM>), including a stator (<NUM>), a rotor (<NUM>) and a shaft (<NUM>), the stator (<NUM>) and the rotor (<NUM>) being received in the shell (<NUM>) and relatively rotatable, the rotor (<NUM>) being connected and rotatable with the shell (<NUM>), the shaft (<NUM>) defining an axial direction (<NUM>) and a circumferential direction (<NUM>), the shaft (<NUM>) being movable in the axial direction (<NUM>) and disposed through the stator (<NUM>), the shaft (<NUM>) and the stator (<NUM>) being relatively non-rotatable in the circumferential direction (<NUM>); and
a battery unit (<NUM>), received in the shell (<NUM>), electrically connected with the motor assembly (<NUM>)
characterized in that
the electric wheel hub further includes two end caps (<NUM>) configured to be respectively connected to two fork arms (<NUM>), wherein the two end caps (<NUM>) are detachably disposed respectively around opposing ends of the shaft (<NUM>), and the shaft (<NUM>) is hollow and configured for a spindle (<NUM>) to be disposed therethrough.