A wave gear apparatus comprising: a spline (22,202) having a top surface (30,210), a bottom surface (32,212), an exterior surface (34,214), and an interior surface (36,216), said top surface (30,210) and said bottom surface (32,212) being axially spaced from one another, and said exterior surface (34,214) and said interior surface (36,216) extending about a center axis connecting said top surface (30,210) with said bottom surface (32,212); a plurality of spline teeth (42,218) extending from said interior surface (36,216) toward said center axis; a wave generator (24,204) rotatably disposed in said spline (22,202); a belt (26,206) extending about said wave generator (24,204), said belt (26,206) including a plurality of belt teeth (52,222) extending radially outwardly from said belt (26,206) engaging said spline teeth (42,218) whereby a total number of said belt teeth (52,222) is less than a total number of said spline teeth (42,218); and an output member (28,208) defining a recess (54,224) receiving said wave generator (24,204) and said belt (26,206) and in engagement with said wave generator (24,204) and said belt (26,206) whereby, in response to a rotational movement from said wave generator (24,204), said output member (28,208) rotates in a direction same or opposite of said wave generator (24,204); characterized by that said output member (28,208) includes a base plate (56,226) disposed in abutment relationship with said belt (26,206) and said wave generator (24,204) and said base plate (56,226) have a periphery (58,228) extending about said center axis; said wave gear apparatus further includes a wall (60,232) extending outwardly from said periphery (58,228) and about said center axis; said output member (28,208) further includes a collar (64,234), located radially inwardly from said base plate (56, 226), coupled to said base plate (56, 226), and extending annularly about said center axis and defining a hole (66,238) extending along said center axis, said collar (64, 234) extends through a bore (50,220) of said wave generator (24,204); and said recess (54, 224) extends about said center axis and between said collar (64,234), said base plate (56, 226), and said wall (60, 232). a spline (22,202) having a top surface (30,210), a bottom surface (32,212), an exterior surface (34,214), and an interior surface (36,216), said top surface (30,210) and said bottom surface (32,212) being axially spaced from one another, and said exterior surface (34,214) and said interior surface (36,216) extending about a center axis connecting said top surface (30,210) with said bottom surface (32,212); a plurality of spline teeth (42,218) extending from said interior surface (36,216) toward said center axis; a wave generator (24,204) rotatably disposed in said spline (22,202); a belt (26,206) extending about said wave generator (24,204), said belt (26,206) including a plurality of belt teeth (52,222) extending radially outwardly from said belt (26,206) engaging said spline teeth (42,218) whereby a total number of said belt teeth (52,222) is less than a total number of said spline teeth (42,218); and an output member (28,208) defining a recess (54,224) receiving said wave generator (24,204) and said belt (26,206) and in engagement with said wave generator (24,204) and said belt (26,206) whereby, in response to a rotational movement from said wave generator (24,204), said output member (28,208) rotates in a direction same or opposite of said wave generator (24,204); characterized by that said output member (28,208) includes a base plate (56,226) disposed in abutment relationship with said belt (26,206) and said wave generator (24,204) and said base plate (56,226) have a periphery (58,228) extending about said center axis; said wave gear apparatus further includes a wall (60,232) extending outwardly from said periphery (58,228) and about said center axis; said output member (28,208) further includes a collar (64,234), located radially inwardly from said base plate (56, 226), coupled to said base plate (56, 226), and extending annularly about said center axis and defining a hole (66,238) extending along said center axis, said collar (64, 234) extends through a bore (50,220) of said wave generator (24,204); and said recess (54, 224) extends about said center axis and between said collar (64,234), said base plate (56, 226), and said wall (60, 232).