A wave gear apparatus comprising: a spline having a top surface , a bottom surface , an exterior surface , and an interior surface , said top surface and said bottom surface being axially spaced from one another, and said exterior surface and said interior surface extending about a center axis (A) connecting said top surface with said bottom surface ; a plurality of spline teeth extending from said interior surface toward said center axis (A); a wave generator rotatably disposed in said spline ; a belt extending about said wave generator , said belt including a plurality of belt teeth extending radially outwardly from said belt engaging said spline teeth whereby a total number of said belt teeth is less than a total number of said spline teeth ; and an output member defining a recess receiving said wave generator and said belt and in engagement with said wave generator and said belt whereby, in response to a rotational movement from said wave generator , said output member rotates in a direction same or opposite of said wave generator ; characterized by that said output member includes a base plate disposed in abutment relationship with said belt and said wave generator and said base plate have a periphery extending about said center axis (A); said wave gear apparatus further includes a wall extending outwardly from said periphery and about said center axis (A); said output member further includes a collar , located radially inwardly from said base plate , coupled to said base plate , and extending annularly about said center axis (A) and defining a hole extending along said center axis (A), said collar extends through a bore of said wave generator ; and said recess extends about said center axis (A) and between said collar , said base plate , and said wall . a spline having a top surface , a bottom surface , an exterior surface , and an interior surface , said top surface and said bottom surface being axially spaced from one another, and said exterior surface and said interior surface extending about a center axis (A) connecting said top surface with said bottom surface ; a plurality of spline teeth extending from said interior surface toward said center axis (A); a wave generator rotatably disposed in said spline ; a belt extending about said wave generator , said belt including a plurality of belt teeth extending radially outwardly from said belt engaging said spline teeth whereby a total number of said belt teeth is less than a total number of said spline teeth ; and an output member defining a recess receiving said wave generator and said belt and in engagement with said wave generator and said belt whereby, in response to a rotational movement from said wave generator , said output member rotates in a direction same or opposite of said wave generator ; characterized by that said output member includes a base plate disposed in abutment relationship with said belt and said wave generator and said base plate have a periphery extending about said center axis (A); said wave gear apparatus further includes a wall extending outwardly from said periphery and about said center axis (A); said output member further includes a collar , located radially inwardly from said base plate , coupled to said base plate , and extending annularly about said center axis (A) and defining a hole extending along said center axis (A), said collar extends through a bore of said wave generator ; and said recess extends about said center axis (A) and between said collar , said base plate , and said wall . <EOS>