Down hole drilling motor with pressure balanced bearing seals
A downhole drilling motor, e.g., a turbodrill is described, which is connected to a string of drill pipe has a rotating shaft for driving a drill bit which may be a rotary bit or a high speed solid head diamond bit. The turbine section has rotor and stator blades which are crescent shaped in cross section with each blade having an exit angle of 14-23/sup 0/ for maximum turbine efficiency. The drilling motor may alternatively be a positive displacement motor. The bearing shaft is provided with chevron rotary seals positioned below the rotary bearings carrying both radial and vertical thrust. Fluid lubricant fills the space from the rotary seals to a predetermined level above the bearings. A piston seals the lubricant chamber and is pressurized by drilling fluid (i.e. mud) flowing through the tool. A layer of lubricant fluid overlies the first piston and has a second piston covering said fluid and transmitting pressure from the drilling fluid to the lubricant fluid surrounding the bearings. The drilling mud is divided into two streams, one of which rotates the drill bit, and the other of which passes through the drill bit. The pressure drop across the drilling motor equals the pressure drop across the drill bit, thus balancing the pressure on the bearing seals.
- Assignee:
- Maurer Engineering Inc
- Patent Number(s):
- US 4225000
- OSTI ID:
- 6625090
- Resource Relation:
- Patent File Date: Filed date 11 Sep 1978
- Country of Publication:
- United States
- Language:
- English
Similar Records
Well drilling tool with diamond radial/thrust bearings
Bearing system for a downhole motor. [Bearings and drill fluid circulation systems]