Pulley/gear that rotates disk table in Sony CD Changer CDP-C77ES, CDP-C87ES, CDP-C715. There is no official replacement part, the gear does not have any part number.
replacement part 
replacement part 
3D model 
Gear/pulley replaced in CD Changer assembly
Faulty gear can be replaced with 3D printed one. Replacement gear was fully tested for correct operation.
Gear position in the schematic:
Gear is compatible with following devices:
Sony CD Changer CDP-C77ES, CDP-C87ES, CDP-C715. .
However, it might work also with other devices – just check your service manual.
Available for purchase in e-shop.