Referring particularly to the drawings, there is shown in FIG. 1 a conventional bicycle 10 which has a tubular frame 12 upon which is mounted a foot operational pedal assembly 14, a front wheel 16 and a rear wheel 18.
The frame 12 includes a handlebar assembly 20 on which is mounted an electrical Switch 22.
The electrical Switch 22 is connected by a conductor 24 to a battery 26.
The battery 26 is connected by a cable 28 to the hub motor assembly 30 of this invention.
The hub motor assembly 30 is shown mounted in conjunction with the front wheel 16.
However, it is considered to be within the scope of this invention that the hub motor assembly 30 could be mounted in conjunction with the rear wheel 18.
The front wheel 16 includes a rubber tire 32 which is mounted on a tire Supporting rim 34.
The tire Supporting rim 34 is connected to a series of wire spokes 36.
The inner end of the wire spokes are attached to annular flange 38 and annular flange 40 of a motor housing 42.
Fixedly mounted between the fork members 44 and 46 of the bicycle frame 12 is a centre shaft 48.
The ends of the centre shaft 48 are threaded with a nut 50 being used to fixedly mount the centre shaft 48 to the fork member 44 and the nut 52 being used to fixedly secure the centre shaft 48 to the fork member 46.
Mounted on the centre shaft 48 are a pair of Spaced apart bearing assemblies 54 and 56.
The motor housing 42 is rotationally mounted on bearing assembly 54.
The motor housing 42 includes a removable access plate 43 which is bolted to housing 42 by bolt fasteners 45.
The centre shaft 48 has a longitudinal centre axis 128.
The centre shaft 48 includes a cutout 58.
The cable 28 is to be passed through the cutout 58 to be located within the internal chamber 60 of the motor housing 42.
The cable 28 comprises a plurality of electrical conducting wires like 62, 64 and 66 which are connected to electronic components Such as component 68, mounted on a printed circuit board 70.
Note that all the wires are not shown and the number of US 6,321,863 B1 3 the wires will vary based on control functions required.
Printed circuit board 70 is then fixedly mounted on a mounting plate 72.
The mounting plate 72 is made of heat conductive material like aluminium and is basically disc shaped and is fixedly attached by means of a set screw 74 and a key 76 to the centre shaft 48.
One side of the mounting plate 72 abuts against a retaining ring 78 which is fixedly mounted to the centre shaft 48.
Integrally formed to the mounting plate 72 is a sleeve 80.
The sleeve 80 has a through opening 82.
Fitted within the sleeve 80 are a pair of bearing assemblies 84 and 86.
Fitted into the bearing assemblies 84 and 86 is a drive shaft 88.
Drive shaft 88 includes a pair of spaced apart annular grooves 90 and 92.
Glue is to be applied within the grooves 90 and 92 with groove 90 to connect with the inner race of bearing assembly 84 and groove 92 connecting with the inner race of bearing assembly 86.
It is the function of the glue to provide a means of further securement of the inner races of the bearing assemblies 90 and 92 so as to affix Such to the drive shaft 88.
In order to minimize the creation of noise and provide for smooth rotation of the drive shaft 88 there is mounted a circular leaf spring 94 between annular ridge 96 of the sleeve 80 and the outer race of bearing assembly 86.
This will exert a constant axial torque applying an actual force against retaining ring 98 which is mounted on the drive shaft 88.
The inner race of the bearing assembly 84 abuts against the retaining ring 98.
The drive shaft 88 is capable of being rotated about rotational axis 100.
It is to be noted that the rotational axis 100 is located parallel to the longitudinal centre axis 128.
The locating of the axes 100 and 128 parallel provides for smoother operation of the motor.
The aft end of the drive shaft 88 includes a spline connection 102 with the forward end of the drive shaft 88 including a spline connection 104.
The spline connection 102 connects with rotor bushing 106.
Rotor bushing 106 is Securely mounted onto a cup shaped member which is defined as rotor 108.
Mounted interiorly of the rotor 108 are a series of magnets 110.
These magnets 110 are to be located directly adjacent but slightly Spaced from a series of radially located coils 112.
There are multiple numbers of the coils 112 each of which comprises electrically conductive wires that are wound about a Series of radially disposed spokes called Stator laminations, which are not shown.
The coils 112 are connected by leads 114 to the printed circuit board 70.
Spline connection 104 connects with the circular shaped driven gear 116.
The driven gear 116 has a centre opening 118.
Press fitted within the centre opening 118 is a clutch assembly 120.
The clutch assembly 120 is mounted on sleeve 122 which is an integral part of the motor housing 42.
Clutch assembly 120 is what is termed as a one-way clutch.
Driven gear 116 is mounted within a chamber 124 which is defined by a circular shaped stub wall 126.
The stub wall 126 is integrally connected to the motor housing 42 and is located within the internal chamber 60.
The operation of the hub motor assembly 30 of this invention is as follows: When the bicycle rider wishes to drive the bicycle 10 by means of electrical power, the user is to manually move Switch 22 from the off position to the on position.
This will result in electrical power from the battery 26 being Supplied through the cable 28 to the printed circuit board 70 and then through lead wires 114 to the coils 112.
This will cause the rotor 108 to be rotated due to the forming of a magnetic field between the coils 112 and the magnets 110.
This rotation of the rotor 108 will cause the rotor bushing 106 to rotate which rotates the drive shaft 88.
The rotation of the drive shaft 88 will cause the driven gear 116 to be rotated.
In comparing the Size between the Spline connection 102 and the driven gear 116, it can be seen that there will be a Substantial number of revolutions of the drive shaft 88 for each revolution of the driven gear 116.
This gear reduction is required So that the motor housing 42 will be rotated at a Substantial number of less revolutions per minute than the drive shaft 88.
Let it be assumed that the driven gear 116 is rotated clockwise in order to achieve the desirable similar rotation of the motor housing 42 which in turn will produce, in essence, the same rotation of the front tire 16 propelling the bicycle 10 on the supporting surface 130.
It is to be noted that the driven gear 116 is mounted by 132 and 120 one-way clutch assembly 132, the construction of which is deemed to be conventional, relative to the sleeve 122.
When the Switch 22 is moved to the off position and power is not being transmitted to the coils 112, the rotor 108 begins to Slow down in rotation and will actually come to a stop in a short period of time.
The front wheel 16 of the bicycle 10 will continue to rotate which is permitted by means of the one-way clutch 120.
In an alternate embodiment of this invention, which is not shown in the drawings, the one-way clutch 120 could be mounted between the drive shaft 88 and the sleeve 80.
In some installations, this mounting would be preferred as it further compacts the overall Structure of the present invention so that the hub motor assembly 30 can actually be Smaller in size.