Floating head reaction turbine rotor with improved jet quality

A method for pressure balancing a rotor in a rotary jetting tool, the method comprising the steps of:

• (a) introducing a pressurized fluid into the rotor via an inlet disposed at a proximal portion of the rotor, such that a direction of the pressurized fluid as it enters the rotor is coaxial with the rotor;
• (b) discharging a major portion of the pressurized fluid introduced into the rotor from a distal portion of the rotor, such that a rotational force is imparted upon the rotor, and such that an axial force is exerted on the rotor, in a direction generally opposite the direction of the pressurized fluid as it enters the rotor;
• and
• (c) directing a minor portion of the pressurized fluid along a different fluid path, thereby exerting an axial force on the rotor in a direction generally corresponding to the direction of the pressurized fluid as it enters the rotor, thus pressure balancing the rotor.

A method for pressure balancing a rotor in a rotary jetting tool, the method comprising the steps of:

• (a) providing a pressure balancing volume defined by the rotor and a non-rotating portion of the rotary jetting tool;
• (b) introducing a pressurized fluid into the rotor via an inlet disposed at a proximal portion of the rotor, such that a direction of the pressurized fluid as it enters the rotor is coaxial with the rotor;
• (c) discharging the pressurized fluid from the rotor from a distal portion of the rotor, such that a rotational force is imparted upon the rotor, and such that the rotor moves axially, thereby reducing a size of the pressure balancing volume;
• (d) directing a portion of the pressurized fluid into the pressure balancing volume, thereby establishing a hydrodynamic bearing between the rotor and the non-rotating portion of the rotary jetting tool;
• and
• (e) increasing the amount of pressurized fluid in the pressure balancing volume, such that the rotor moves axially, thereby increasing a size of the pressure balancing volume, until a vent placing the pressure balancing volume in fluid communication with an ambient volume is opened, thereby pressure balancing the rotor.

A rotary jetting apparatus comprising:

• (a) a housing defining a fluid path for a pressurized fluid;
• (b) a rotor, at least a portion of which is disposed coaxially within the housing, the rotor including a proximal end and a distal end, the rotor being configured to rotate relative to the housing and to move axially relative to the housing, the distal end comprising at least one nozzle in fluid communication with the fluid path, the at least one nozzle being configured to discharge a jet of the pressurized fluid, thereby causing the rotor to rotate relative to said housing;
• (c) a first pressure balance volume defined by the housing and the rotor, the first pressure balance volume being disposed adjacent to the proximal end of the rotor;
• (d) a second pressure balance volume defined by the housing and the rotor, the second pressure balance volume being disposed adjacent to the distal end of the rotor;
• and
• (e) a vent configured to selectively place the first pressure balance volume in fluid communication with an ambient volume, based upon an axial position of the rotor relative to the housing.

A rotary jetting apparatus comprising:

• (a) a housing defining a fluid path for a pressurized fluid;
• (b) a rotor, at least a portion of which is disposed coaxially within the housing, the rotor including a proximal end and a distal end, the rotor being configured to rotate relative to the housing, the distal end comprising at least one nozzle in fluid communication with the fluid path, the at least one nozzle being configured to discharge a jet of the pressurized fluid, thereby causing the rotor to rotate relative to said housing;
• and
• (c) a centrifugal brake disposed between the proximal end and the distal end of the rotor, the centrifugal brake being configured to frictionally engage the rotor at a predetermined rotational speed, thereby limiting a maximum rotational speed of the rotor.