Elliptical machine capable of realizing three-dimensional pedaling training

An elliptical machine, comprising:

• a machine frame;
• two pedal units located on opposing left and right sides, each said pedal unit comprising a vertical arm, a driving main arm, a pedal mount, a slanting rod, a pedal and a rocking link, said vertical arm having a top end thereof pivotally connected to said machine frame and swingable back and forth relative to said machine frame, said driving main arm having a front end thereof pivotally connected to a bottom side of said vertical arm and swingable up and down relative to said machine frame, said pedal mount having a front end thereof pivotally connected to an opposing rear end of said driving main arm and swingable left and right relative to said driving main arm, said pedal being pivoted to an opposing rear end of said pedal mount and swingable left and right relative to said pedal mount, said slanting rod having a front end thereof pivotally connected to said vertical arm in a vertically swingable manner and located above the front end of said driving main arm and an opposing rear end thereof pivotally connected to the front end of said pedal mount in a universally rotatable manner, said rocking link having a front end thereof pivotally connected to the opposing rear end of said driving main arm and swingable back and forth and up and down relative to said driving main arm and an opposing rear end thereof pivotally connected to said pedal in a universally rotatable manner;
• two handlebars located on opposing left and right sides of said machine frame, said two handlebars each having a bottom end thereof respectively pivotally connected to a center of the respective driving main arms and swingable back and forth relative to the respective driving main arms;
• and
• a flywheel set comprising two flywheels and two crankshafts, said two flywheels being respectively pivotally mounted on the left and right sides of said machine frame in a rotatable manner, said two crankshafts having respective one ends thereof respectively connected to said two flywheels and respective opposite ends thereof respectively connected to said driving main arms so that said two crankshafts are drivable by said driving main arms to rotate said two flywheels;
• and
• a step length adjustment unit, said step length adjustment unit comprising a motor, a lead screw, an internally-threaded tube and a slide, said motor being pivotally connected to said machine frame in a vertically swingable manner, said lead screw having one end thereof connected to said motor, said internally-threaded tube being threaded onto said lead screw and drivable by said lead screw to move along an axial direction of said lead screw, said slide being connected to said internally-threaded tube and the top ends of the two said vertical arms of said two pedal units so that said slide is drivable by said internally-threaded tube to move the two said vertical arms of said two pedal units;
• wherein said step length adjustment unit further comprises two guide rails respectively disposed on opposing left and right sides of the two pedal units;
• said slide comprises two guide wheels respectively disposed on opposing left and right sides thereof and respectively rotatably mounted in said guide rails.