Speed changeable gear drive apparatus for a wheeled vehicle

A speed changeable gear drive apparatus for transmitting a drive of an output shaft of an electrically powered motor to drive a wheeled vehicle, comprising:

• a pair of frame supports disposed to be spaced apart from each other in an axial direction;
• a drive shaft with a first axis oriented in the axial direction, said drive shaft having two ends journalled respectively on said frame supports, and being adapted to couple with and be driven by the output shaft to rotate about the first axis;
• first and second driving gears respectively having first and second teeth in different number and mounted in tandem on said drive shaft and so as to be rotatable therewith;
• a driven shaft with a second axis disposed to be journalled relative to said frame supports, said driven shaft extending parallel to said drive shaft, and including left and right end portions and an intermediate portion interposed therebetween;
• a first driven gear mounted on said left end portion and rotatable with said driven shaft, said first driven gear having a first rim portion with third teeth thereon to mesh with said first teeth, and a first hub portion which includes a first outer annular wall radially spaced apart from said first rim portion, and a first inner annular wall opposite to said first outer annular wall radially, said first inner annular wall being disposed around and being spaced apart from said left end portion so as to define an annular coupling area;
• a plurality of first spline members disposed on said first inner annular wall and angularly displaced from one another;
• an annular bearing member including an inner annular race sleeved on and rotatable with said first outer annular wall, and an outer annular race opposite to and rotatable relative to said inner annular race and spaced apart from said first rim portion radially to define an annular accommodation area;
• a second driven gear mounted on said intermediate portion, and including a second rim portion having fourth teeth thereon to mesh with said second teeth, and a second hub portion which includes a second inner annular wall radially opposite to said second rim portion, and a second intermediate annular portion interposed between said second rim portion and said second inner annular wall;
• an annular anchoring member disposed to be coaxial to and extending from said second intermediate annular portion and towards said first driven gear and into said annular accommodation area so as to be sleeved on and be rotatable with said outer annular race of said annular bearing member;
• a plurality of second spline members disposed on said second inner annular wall and angularly displaced from one another;
• an annular coupling member sleeved on and retainingly shiftable relative to said driven shaft along the second axis, and including an output end portion adapted to drive the wheeled vehicle, and a splined end portion disposed to be spaced apart from said output end portion along the second axis such that when said annular coupling member is shifted to a first position or a second position, said splined end portion is coupled with said first spline members or with said second spline members so as to transmit the drive of said first driving gear or said second driving gear to said output end portion;
• and
• a shifting member disposed to shift said annular coupling member between the first and second positions.