Power assist system and method for a vehicle

Abstract

A power-assist system and method for a bicycle, comprising three main sections, namely: a motor section, a speed-reducing section, and a power-assist section. It is capable of operating in four modes, namely: a) a power-assist pedaling mode (where the bicycle rider is pedaling to supply power and the power-assist section is also providing power); b) a pedal only mode (where power is supplied solely by pedaling the bicycle; c) a power-assist only mode (where the bicycle rider is not providing any power by pedaling, and all the power is supplied by the power-output section); and d) a coasting no-power mode where the bicycle is traveling with the pedal section stationary, and no power is being delivered either by the pedal section or the power-assist drive system.

1 . A motor assist power system for a bicycle which has, at least one drive wheel, a second wheel, and a bicycle frame with front and rear ends, said system comprising:
 a) a pedal section comprising a crank shaft connecting a plurality of pedal members, a crank housing in which the crank shaft is located;   b) a sprocket section coupled to the pedal section having a power drive connection to the drive wheel;   c) a power-assist drive section comprising a power assist drive member concentrically mounted around and mechanically coupled to said crank shaft;   d) a motor positioned directly forward of the second wheel and the crank housing, wherein the motor is mechanically coupled to the power-assist drive section;   e) an overrunning drive connection coupled to the power-assist drive connection; whereby said bicycle is configured to operate in four operating modes, namely:
 i a power-assist mode where a bicycle rider is pedaling to supply power, and the motor through the power-assist section is providing additional power; 
 ii a pedal-only mode where power is being supplied solely by pedaling the bicycle; 
 iii the power-assist-only mode where the bicycle rider is not providing power by pedaling, but power is supplied by the motor through the power output section; 
 iv a coasting no-power mode where the bicycle is traveling with the pedal section stationary, and no power is being supplied by either the pedal section or the power-assist drive section. 
   
     
     
         2 . The motor assist power system as recited in  claim 1  wherein the power drive is a chain-and-sprocket power drive. 
     
     
         3 . The motor assist power system as recited in  claim 1  further comprising a speed reducing section positioned between and mechanically coupled between the motor and the overrunning drive connection. 
     
     
         4 . The motor assist power system as recited in  claim 1  wherein the speed reducing section comprises an eccentric gear cluster. 
     
     
         5 . The motor assist power system as recited in  claim 4  wherein the speed reducing section comprises epicyclical eccentric gear cluster further comprising a power input component and a power output component wherein the power input component is structurally and rotationally co-axial with the power output component. 
     
     
         6 . The motor assist power system as recited in  claim 1  wherein the motor is a gasoline powered motor. 
     
     
         7 . The motor assist power system as recited in  claim 1  wherein the motor is an electrically powered motor. 
     
     
         8 . The motor assist power system as recited in  claim 7  further comprising a gasoline powered motor. 
     
     
         9 . The motor assist power system as recited in  claim 1  wherein the motor is positioned laterally between the second wheel and the crank housing.