Motorized driving device

A motorized driving device for mounting to a frame of a bicycle, said bicycle comprising a pedal drive mechanism coupled to a chain for transferring a drive force to at least one chainwheel, said motorized driving comprising:

• a) a power source of rotary power, said power source further comprising:
• i) a battery pack;
• and
• ii) an electric motor coupled to said power transmission mechanism;
• said battery pack detachably fixed to said electric motor;
• said battery pack electrically connecting to said electric motor to provide electric power to said electric motor;
• and
• b) a power transmission mechanism for coupling between said pedal drive mechanism and said chain;
• said power transmission mechanism further comprising a first unidirectional power transmission module and a second unidirectional power transmission module, such that an auxiliary power transmitted by said power transmission mechanism from said power source to said chain is independent from a pedal power transmitted by said power transmission mechanism from said pedal drive mechanism to said chain;
• wherein said first unidirectional power transmission module further comprising an active flange for coupling to said pedal drive mechanism, and said second unidirectional power transmission module further comprises a passive flange coupled to said power source;
• said active flange providing said pedal power from said pedal drive mechanism to said chain;
• said passive flange providing said auxiliary power from said power source to said chain;
• said second unidirectional power transmission module further comprising:
• i) a plurality of pawl bases fixed to a crank shaft which is capable of fitting into said pedal driving mechanism;
• ii) a plurality of pawls each disposed in one of said plurality pawl bases;
• and
• iii) a second ratchet mounted on an inner circumference of said active flange;
• said second ratchet further comprising a plurality of second saw teeth formed on an inner circumference of said second ratchet;
• said plurality of second saw teeth engaging with said plurality of pawls in a way that when said crank shaft rotates in a first direction with respect to said active flange, said plurality of pawl bases driving said active flange to move in said first direction;
• when said active flange rotates in said first direction with respect to said crank shaft, said crank shaft not driven by said active flange.

A motorized driving device for mounting to a frame of a bicycle, said bicycle comprising a pedal drive mechanism coupled to a chain for transferring a drive force to at least one chainwheel, said motorized driving comprising:

• a) a power source of rotary power, said power source further comprising:
• i) a battery pack;
• and
• ii) an electric motor coupled to said power transmission mechanism;
• said battery pack detachably fixed to said electric motor;
• said battery pack electrically connecting to said electric motor to provide electric power to said electric motor;
• and
• b) a power transmission mechanism for coupling between said pedal drive mechanism and said chain;
• said power transmission mechanism further comprising a first unidirectional power transmission module and a second unidirectional power transmission module, such that an auxiliary power transmitted by said power transmission mechanism from said power source to said chain is independent from a pedal power transmitted by said power transmission mechanism from said pedal drive mechanism to said chain;
• c) a sensor module for sensing a pedal strength and a pedal speed on said pedal driving mechanism;
• and
• d) a controller connected to said sensor module and said power source;
• said controller receiving a data representing said pedal strength and said pedal speed from said sensor module and sending a command to said power source to control an operation of said power source.

A motorized driving device for mounting to a frame of a bicycle, said bicycle comprising a pedal drive mechanism coupled to a chain for transferring a drive force to at least one chainwheel, said motorized driving comprising:

• a) a power source of rotary power, said power source further comprising:
• i) a battery pack;
• and
• ii) an electric motor coupled to said power transmission mechanism;
• said battery pack detachably fixed to said electric motor;
• said battery pack electrically connecting to said electric motor to provide electric power to said electric motor;
• and
• b) a power transmission mechanism for coupling between said pedal drive mechanism and said chain;
• said power transmission mechanism further comprising a first unidirectional power transmission module and a second unidirectional power transmission module, such that an auxiliary power transmitted by said power transmission mechanism from said power source to said chain is independent from a pedal power transmitted by said power transmission mechanism from said pedal drive mechanism to said chain;
• and
• c) a two-stage gear reduction module coupled between said power source and said power transmission mechanism wherein said gear reduction module further comprises:
• a casing;
• a planet gear reduction stage contained in said casing;
• said planet gear reduction stage connecting to said power source;
• a cylindrical gear reduction stage contained in said casing, said cylindrical gear reduction stage connecting to said planet gear reduction stage and coupled to said power transmission mechanism, wherein said rotary power from said power source is received by said planet gear reduction stage and outputted to said cylindrical gear reduction stage, said cylindrical gear reduction stage outputting said auxiliary power with reduced speed and increased torque compared to said rotary-power from said power source;
• said motorized driving device further comprising a crank shaft which is capable of fitting into said pedal driving mechanism;
• said gear reduction module capable of reducing a speed of said rotary power outputted by said power source and increase a torque thereof.

A method of installing a motorized driving device to a bicycle, said bicycle comprising a frame, a bottom bracket located at the bottom of said frame, a crank shaft rotatably hinged in said bottom bracket, a bicycle sprocket fixed to said crank shaft and on which a chain rests, and two crank arms fixed to said crank shaft;

• said method comprising the steps of:
• a) removing said crank shaft, said crank arms and said bicycle sprocket from said bicycle;
• b) fixing a body of said motorized driving device to said frame of said bicycle, said motorized driving device comprising a battery pack and an electric motor coupled to said power transmission mechanism;
• said battery pack electrically connecting to said electric motor to provide electric power to said electric motor;
• wherein said fixing step further comprises the steps of:
• i) inserting an inner sleeve of said motorized driving device into said bottom bracket;
• a device shaft rotatably received in said inner sleeve;
• said device shaft connecting to said body of said motorized driving device;
• ii) tightening a screw cap on a protruding end of said inner sleeve to fix said inner sleeve to said bottom bracket;
• iii) positioning a screw protruding from said body between two forks of a chain stay of said frame of said bicycle;
• iv) placing a holding plate on said chain stay such that said chain stay placed between said body of said motorized driving device and said holding plate;
• said screw penetrating said holding plate;
• and
• v) tightening a first nut on said screw to fix said holding plate to said screw, whereby said body of said motorized driving device mounted on said frame of said bicycle;
• and
• c) connecting said chain to said body of motorized driving device.

A motorized driving device for mounting on a bicycle, said bicycle comprising a frame and a bottom bracket located at the bottom of said frame, said motorized driving device comprising:

• a) a body;
• and
• b) an inner sleeve connected to said body;
• said inner sleeve capable of inserting into said bottom bracket, such that said body of said motorized driving device is secured to said frame of said bicycle;
• c) a battery pack;
• d) an electric motor coupled to said power transmission mechanism;
• said battery pack detachably fixed to said electric motor;
• said battery pack electrically connecting to said electric motor to provide electric power to said electric motor;
• e) a first fastening means;
• said inner sleeve capable of fixing to said bottom bracket by said first fastening means;
• said first fastening means further comprising a screw cap;
• said inner sleeve capable of fixing to said bottom bracket by tightening said screw cap on a protruding end of said inner sleeve to fix said inner sleeve to said bottom bracket.