Single direction thrust ball bearing is a shaft washer (slide fit) with raceway groove, ball & cage assembly and a housing washer (tight fit) with raceway groove. The contact angle is 90. Shaft washer (rotating ring) have a flat back face, the housing washer (fixed ring) can have either a flat or spherical back (to take some misalignment) and may be provided a with additional sphered seat washer.
They accommodate axial loads in one direction.
They should not be subjected to any radial load.
They are provided with pressed steel cages (in small sizes) or machinal brass or steel cages (in large sizes)
Generally these bearings are unsuitable for high speed operation.