Downhole mud motor

摘要

A downhole mud motor (100) is disclosed which has an improved bearing mandrel (107) and a bearing stop (105) to transfer a larger percentage of the weight of a drill string to the bit. Also improved sealing systems (113) (114) (220) (515(706) for the transmission section and bearing section (116) (310) (117) (118) (119) prevent drilling mud from entering critical components. A piston stop is provided to prevent the piston from damaging other parts as the piston moves under pressure. Compensating pressure assembly (204) preferably including a disk (1408) is placed in the lower housing (108) to prevent pressure from building up in the bearing section (308). A combination of grooved ball seats (130) and circumferentially spaced balls (127) are provided in the transmission section (200) (207) to allow for greater flow of lubricant around the ball bearings.