Harmonic drive bearing is cross roller structure.According to its application area there are two types ,one is outer ring split and inner ring integraty ,another one is outer ring and inner ring all integraty.Rolling body are cylindrical rollers which arranged orthogonality,this structure can make one bearing can bear the load from every direction e.g. radial,axial and tilting torque etc. Bearing with high rigidity,rotation accurancy and load carrying capacity. This series bearing has compact appearance,with mounting hole,customer can mount directly,suitable for every kinds of harmonic drives.