Powder metallurgy unidirectional needle roller bearings are bearings that produce metal powder or use metal powder (or a mixture of metal powder and non-metal powder) as raw materials. After forming and sintering, they are assembled with spring plates and needle rollers to form a unidirectional motion bearing. They can be used as converters, check devices, and overrunning clutches, and are widely used in fitness equipment, cash counting machines, washing machines, fishing gear, dishwashers, surface mount machines, textile machines, floor sweepers, toy cars, and other transmission components that require reverse movement.