Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B13/00—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion
  • F01B13/04—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder
  • F01B13/06—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder in star arrangement
  • F01B13/068—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder in star arrangement the connection of the pistons with an actuated or actuating element being at the inner ends of the cylinders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
  • F03C1/00—Reciprocating-piston liquid engines
  • F03C1/22—Reciprocating-piston liquid engines with movable cylinders or cylinder

Definitions

• This invention relates to hydraulic motors which derive their output power from the flow of fluid under pressure to the rotating parts.
• the invention will be described in relation to a hydraulic motor of the kind that may be installed as a down-hole drill motor at the lower end of a long drill string and be driven by the pressurised slurry normally used for drill bit lubrication and cooling.
• the invention is not limited thereto as the motor (albeit with or without minor modifications) may be used with general purpose hydrostatic transmission systems as a high torque/slow speed motor.
• Down-hole drill motors are known in various forms, the most familiar and widely known of which, is the turbo ⁇ drill.
• the turbo-drill is based on the multi-stage turbine principle with drilling mud as the working fluid.
• positive displacement hydraulic motors used commercially, or which may still be at the experimental stage, include eccentric lobed rotor (as in the mono pump) and flexible vane types. Most down-hole turbo-drills or positive displacement motors derive their high torque/slow speed characteristic from a gradual pressure drop of the motive fluid over a relatively large axial length.
• a hydraulic motor comprising a body defining a chamber that has a plurality of cylinders formed therein, a drive element within the chamber adapted to be coupled to an output shaft, a multi-lobed rotor mounted on the drive element with the lobes adapted to co-operate sequentially with the cylinders, a passageway in each lobe through which fluid applied to the interior of the rotor is directed to the cylinder during pre-deter ined locations of each lobe whereby the lobe is forced from the cylinder and the force so produced is transferred as torque to the drive element.
• the motor is capable of staged assembly whereby each individual power module or motor may be connected in line with one or more further modules to increase the final output shaft power.
• the working fluid is the pressurized mud slurry used for flushing of drilling debris and lubrication and cooling of the drill bit at the end of a drill string.
• the working fluid passes through each stage in turn and a portion of the total flow is extracted at each intermediate stage to provide motive power for the module of that stage.
• the motor modules are, in effect, operating hydraulically in parallel and mechanically in series.
• Fig. 1 is a cross-sectional view of a single stage hydraulic motor according to one embodiment of the invention.
• Fig. 2 is a cross-sectional view of a second stage or module hydraulic motor adapted to be connected to the first stage shown in Fig. 1
• Fig. 3 is a diagrammatic representation of the porting arrangement by which fluid is transmitted to and discharged from the cylinders of the hydraulic motor shown in
• Fig. 1 is a diagrammatic representation of the porting arrangement by which fluid is transmitted to and discharged from the cylinders of the motor shown in Fig. 2,
• Fig. 5 is an exploded view of the central portion of the motor shown in Fig. 1
• Fig. 6 is a schematic view of a down-hole drill string, motor and drill bit arrangement.
• the hydraulic motors shown in Figs 1 and 2 each include a hollow body 10 that is closed by a non-drive end housing 12 and a drive end housing 13 all of which are held in position by bolts 11.
• a plurality of radial slots or recesses 14 formed in the inner face of the body 10 constitute the working cylinders of the motor (see Fig. 3).
• the first and second stages are substantially similar and will, when appropriate, be described together.
• the end housings 12 and 13 have taper roller bearings 16, 17 which support a drive element 15 in the chamber defined by the body 10. Oil or grease is sealed within the bearings 16, 17 by polymer seal plates 18 which act against mating faces of the drive element or rotor 15 and by plates 18a sealing against locking rings 20 attached to the non- drive end stub shafts 24 (Fig. 2) and 24a (Fig. 1) and to the drive-end stub shafts 26 (Fig 2) and 26a (Fig. 1). As shown in Fig. 2, sealing pressure is provided by compression springs 40, 41 which act against seal plates 18 and 18a respectively.
• the drive element 15 (see Fig. 2) consists of two flanged components 19, 19a that are connected together by three equally spaced circular, hollow pins 21. Each pin 21 carries a rotor 22 having three lobes 23 free to rotate on the pin 21.
• the drive element for the second stage motors also has three transfer tubes 50 between the flange components 19, 19a (see Fig. 4) and the drive element for the first stage has three rotor torsion pins 51 between the flange components 19, 19a (see Fig. 3).
• Figs. 3 and 4 the rotor lobes 23 engage each cylinder 14 in turn as the drive element 15 and rotors 22 turn (in opposite directions) thereby forming a sealed chamber to which the pressurised fluid is admitted.
• the porting arrangement and method of transfer by which fluid is transmitted to and discharged from the cylinders 14 is shown diagramatically in Fig. 3 for the first stage motor of Fig. 1 and in Fig. 4 for the second stage motor of Fig. 2.
• High pressure (i.e. inlet) fluid is indicated by solid lines and low pressure (i.e. discharge) fluid by broken lines.
• the non-drive end flange component 19 has a hollow stub shaft 24 (Fig 2), 24a (Fig. 1) and a - b
• pressurised fluid passageway 25 (Fig. 2), 25a (Fig. 1) through which the driving fluid is introduced into the motors of Figs. 1 and 2 in the direction of arrows A.
• the drive end flange component 19a has a hollow stub shaft 26 (Fig. 2) having a passageway 27 (Fig. 2) through which a portion of the pressurised driving fluid is discharged in the case of the Fig. 2 motor in the direction of arrows B to the motor of Fig. 1.
• An annular connector flange 28 is used to join the first and second stages and the drive end stub shaft 26 of one unit receives the non-drive end shaft 24a of the next unit with a seal 29 therebetween.
• Each rotor pin 21 has a port slot 31 which overlaps, in turn, with three corresponding ports 32 in the rotor • 22.
• the rotor ports 32 provide a passageway for fluid under pressure through each lobe 23 into the cylinder chambers 14 to provide the power stroke by forcing the lobe from the cylinder.
• the rotor ports 32 open at the top dead centre of each lobe 23 in a cylinder 14 and close at the point of departure of the lobe from the cylinder.
• the force produced on the rotor 21 is transferred as torque to the drive element 15 and to the final output shaft (not shown) of the motor.
• the body of the motor is full of fluid at discharge pressure.
• discharge fluid is then released from the first stage by passageway 34 in the non-drive end plate 12 and passageway 35 in the drive end plate 13, in the direction of arrows D.
• FIG. 5 The use of an hydraulic motor of the invention as a down-hole drill motor is shown in Fig. 5 where the first motor unit 60 is bolted direct to- the lower flange of the drill string of pipes 61 which provide the inlet supply fluid from supply line 62.
• the outward shaft of the final motor unit is connected direct to the drill bit 64 or through an intermediate coupling.
• the hydraulic motor derives its output power from a flow of fluid supplied under pressure to the rotating parts.
• the motor is designed principally as a down the hole drill motor for deep wells it may also be applied (with suitable modifications) to general purpose hydrostatic transmission systems as a high torque/slow speed motor.
• the motor can be readily adapted for 'staged' assembly whereby each individual motor as described above may be connected in line with one or more further motors to increase the final output shaft power.
• the working fluid When used as a drill motor, the working fluid is pressurised mud slurry as used conventionally for flushing, lubrication and cooling a drill bit, which passes through each stage in turn. A portion of the total flow is extracted at each motor stage to provide motive power for that drive element. After discharge from the working stroke the fluid is released from the motor body to provide flushing, lubrication and cooling for the drill bit attached to the motor output shaft.
• the hydraulic motor is not subjected to the stringent diametral constraints of a down the hole drill motor and thus the inlet and outlet connections for the working fluid (such as hydraulic oil) could be located in one plate or casting at the non-drive end of the motor.
• the working fluid such as hydraulic oil

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Hydraulic Motors (AREA)

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Publications (2)

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• 1986
  • 1986-05-06 JP JP61502803A patent/JPS62502834A/ja active Pending
  • 1986-05-06 WO PCT/AU1986/000126 patent/WO1986006787A1/en not_active Application Discontinuation
  • 1986-05-06 EP EP19860903127 patent/EP0223788A4/en not_active Withdrawn
  • 1986-05-06 BR BR8606658A patent/BR8606658A/pt unknown
  • 1986-05-07 ZA ZA863426A patent/ZA863426B/xx unknown
  • 1986-05-08 CN CN198686103246A patent/CN86103246A/zh active Pending

Non-Patent Citations (2)

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