| 摘要 |
A fluid motor for incorporation downhole in a well drill string includes a thrust bearing disposed in an annular space between the output shaft of the motor and the motor housing, the bearing including an inner race fast with shaft, and outer race fast with the housing and rolling contact elements between the races. Drilling mud drives the motor but is prevented from reaching the thrust bearing by at least one mechanical seal including inner and outer friction discs which are in sealing engagement with each other over confronting radial faces thereof and which are fast with the inner and outer races respectively and secured to the shaft and the housing respectively. Particularly for driving jet bits. The seal is effective regardless of the direction of thrust, and the thrust s taken jointly by the bearing and the seal so that the service life of these components is extended. |
