Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
  • F04C14/28—Safety arrangements; Monitoring
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
  • E21B43/121—Lifting well fluids
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B47/00—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps
  • F04B47/02—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps the driving mechanisms being situated at ground level
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
  • F04C15/0057—Driving elements, brakes, couplings, transmission specially adapted for machines or pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D57/00—Liquid-resistance brakes; Brakes using the internal friction of fluids or fluid-like media, e.g. powders
  • F16D57/06—Liquid-resistance brakes; Brakes using the internal friction of fluids or fluid-like media, e.g. powders comprising a pump circulating fluid, braking being effected by throttling of the circulation

Definitions

• Drive head for a rotationally drivable linkage, in particular for driving a borehole pump
• the invention relates to a drive head according to the preamble of claim 1.
• any load with one of the torques to be transmitted to the drill pipe results in the drill pipe being twisted elastically and thus in elastic deformation work stores in itself, which can suddenly be released when the load stops with the torque.
• This deformation work which can also be referred to as twisting energy, depends on the torque applied and the length of the boom.
• the torque is transmitted, for example, from an electric motor to the sleeve via a transmission with a reduction ratio of 4: 1 and from there via the linkage, which may be more than a thousand meters long, to a pump rotor connected to its lower end.
• the return brake has a hydraulic circuit with a pump and a throttle point.
• the pump has a rotor, which is connected via a directional lock to the sleeve in a torque-transmitting manner only in the event of a return, via which the rod is driven in normal operation.
• Another known drive head of the type mentioned (DE 196 28 950 AI) has as a return brake a hydrodynamic retarder with a rotor blade wheel and a stator blade wheel, which together form a toroidal working space which is always filled with fluid during operation.
• the rotor blade wheel is at least indirectly in constant drive connection with a drive machine for the linkage.
• the blading of the rotor and stator impeller is designed so inclined to a parting plane between these two impellers that due to the direction of the blades with the linkage driven by the prime mover, the rotor impeller rotates essentially in freewheeling mode, on the other hand if the power flow from the prime mover is interrupted when it occurs of restoring torques on the borehole linkage, a braking torque is generated between the rotor blade wheel and the stator blade wheel.
• Another known drive head for a drivable borehole linkage also has a hydrodynamic retarder with a rotor blade wheel and a stator blade wheel as a return brake; the rotor blade wheel is connected by a mechanical directional lock to a sleeve enclosing the linkage in such a way that the rotor blade wheel is driven only when it returns.
• Viscous brakes (DE 39 09 231 AI) are also known to be suitable for quickly braking masses with high kinetic energy; Such brakes, however, have so far not been proposed as return brakes for drivable rods, in particular borehole rods.
• the stator of a reverse brake is prevented from rotating relative to the housing by a lock.
• the lock can only be released when the drill string is essentially free of twisting energy. It can thus be safely checked whether the twist energy has essentially been reduced. This check must be done manually.
• the invention is also based on the object of developing a generic drive head, in particular for driving a borehole pump, for a rotationally drivable linkage, which has a return brake, in such a way that it can be safely determined whether the twisting energy has essentially been reduced.
• the inventive sensing of the fluid pressure in connection with the throttle point enables the residual pressure that is generated in the fluid by the hydrodynamic return brake to be recognized.
• This residual pressure depends on the twisting energy stored in the linkage and therefore enables a statement to be made about a potential hazard emanating from the drive head. If the pressure is below a predetermined threshold value, it can be assumed that the twisting energy has been almost completely reduced and is no longer a hazard.
• the monitoring signal can, for example, be perceived visually or tactilely by maintenance personnel. Due to the arrangement described in claim 2, the drive head can be realized particularly easily.
• the drive head is again in a basic state after the twisting energy stored in the linkage has been almost completely reduced.
• viscous fluid may initially have blocked the throttle point, so that a controlled reduction of the twisting energy stored in the linkage is only possible when the ambient temperature rises.
• the monitoring signal is switched off according to the invention, so that the drive head is in its basic position and could start again automatically.
• the design according to claim 4 enables a particularly robust and reliable type of pressure sensing.
• the development according to claim 5 makes it possible to completely reduce a residual pressure remaining in the fluid stream by removing a stop.
• the design according to claim 6 is particularly expedient, in which a fluid flow that is stowed in front of the piston is specifically discharged into a fluid line.
• the device according to the invention can be designed to be particularly compact.
• a positive coupling between the monitoring signal and the rotary drive is ensured, so that an automatic restart of the rotary drive is prevented as long as excessive twisting energy is stored in the linkage.
• Fig.l a drive head according to the invention in a vertical axial section; 2 shows the enlarged section II in Fig.l.
• the drive head shown in Fig.l serves to rotate a vertical rod 10, which extends from the earth's surface into a borehole and is connected at its lower end to a pump rotor, not shown, for example a helical rotor of an eccentric screw pump.
• the housing 12 encloses a gear chamber 14, a substantially horizontal partition 16, which separates the gear chamber 14 from a sealing chamber 18 arranged below it, and a locking and braking chamber 20, which is also arranged under the gear chamber 14 and from the side of it lying sealing chamber 18 is separated by a vertical partition wall 22.
• a lower passage 24 and an upper passage 26 are formed vertically one above the other in the housing, through which the linkage 10 can be lowered and raised.
• the gear chamber 14 and the locking and brake chamber 20 are constantly connected to one another by an oil passage 28 and are essentially filled with gear oil.
• the sealing chamber 18 contains a barrier fluid, the level of which can be monitored by a monitoring device, not shown, for example a sight glass or a sensor.
• a sleeve 30 extends vertically downwards into the gear chamber 14 and further through the horizontal intermediate wall 16 into the sealing chamber 18.
• the sleeve 30 is in the intermediate wall 16 by means of a lower radial bearing 32 and immediately above an axial bearing 34 and is also mounted in the upper passage 26 of the housing 12 by means of an upper radial bearing 36.
• the sleeve 30 is connected to the linkage 10 in a torque-transmitting manner by a coupling 40 of a conventional type.
• the clutch 40 is releasable to raise or lower the linkage 10.
• a lower end region of the sleeve 30 is enclosed by a cup-shaped insert 42 which is inserted into the housing 12 through the lower passage 24 and on this is screwed and sealed.
• the insert 42 is sealed against the sleeve 30 by a lower mechanical seal 44 enclosed by it.
• an upper mechanical seal 46 is arranged, which seals the sleeve 30 against the horizontal intermediate wall 16.
• a countershaft 48 is arranged as part of a transmission 50, via which the sleeve 30, and thus the linkage 10, can be driven by a motor, not shown, for example an electric motor, which is arranged outside the housing 12.
• the countershaft 48 is mounted in the housing 12 by means of a lower bearing 52 and an upper bearing 54 and, between these two bearings, has a pinion 56 attached to it or, as shown, integrally formed with it, which is in constant engagement with the gear 38 .
• the countershaft 48 has a shaft journal 58 which extends downward beyond the lower bearing 52 and carries a directional lock 60.
• the directional lock 60 includes two bearings 62 arranged on the shaft journal 58 at an axial distance from one another, between which an inner liner 64 connected to the shaft journal 58 for common rotation is arranged.
• the inner liner 64 is enclosed at a radial distance from an outer liner 66 which is mounted on the two bearings 62.
• the two liners 64 and 66 are arranged coaxially with the countershaft 48 and delimit an annular space which contains clamping rollers 68 which are dependent on the direction of rotation.
• the directional lock 60 designed in this way acts in the operating direction of rotation of the countershaft 48 as a freewheel, but locks and drives a hydraulic pump 70 when the countershaft 48 is driven in the opposite direction.
• the pump 70 includes a pump shaft 72 which is flanged to the outer sleeve 66 and carries a pump rotor 74.
• the pump rotor 74 is connected to the pump shaft 72 for common rotation, for example by a multi-groove profile, and is enclosed by a pump stator 76.
• a pump stator 76 In the pump rotor 74 several, for example six radial cylinders 78 are incorporated at equal angular intervals, each of which contains a piston 80.
• Each piston 80 is biased radially outwards by a spring 82 and is supported via a sliding body 84 on an annular oval track 86 belonging to the pump stator 76, so that the piston 80 reciprocates with each full revolution of the pump rotor 74 Movement.
• a control body 88 arranged next to it and axially resiliently biased, which is secured against rotation on the pump stator 76.
• a throttle point 90 which belongs to a hydraulic circuit fed by the pump 70, is arranged radially outside the control body 88 in the pump stator 76.
• This circuit also includes an inlet duct 92, which leads from the locking and brake chamber 20 through the pump stator 76 and the control body 88 to the cylinder 78, and an outlet duct 94, which leads from the cylinder 78 through the control body 88 and the pump stator 76 to the throttle point 90 leads.
• the oil passage 28 enables a constant fluid exchange between the gear chamber 14 and the locking and brake chamber 20. As a result, heat that is generated by the throttling is distributed , on the entire fluid, which in the example shown is contained to a considerable extent in the gear chamber 14 and lubricates the gear 50.
• the directional lock 60 and the pump 70 are installed in the housing 12 from below through an opening closed with a cover 96. Also flanged to the underside of the housing 12 is an adapter 98 coaxial with the linkage 10, which carries the entire drive head and secures it against rotation.
• Fig.2 the detail designated II in Fig.l is shown.
• the throttle point 90 is formed by a commercially available throttle that is screwed into a threaded bore 100 in a piston 102 in a fluid-tight manner.
• the piston 102 has an axial bore 104, which connects the outlet channel 94 to the throttle point 90 in a fluid-conducting manner.
• the flow resistance in the bore 104 is considerably lower than the flow resistance in the throttle point 90.
• the piston 102 is axially displaceably mounted in a stepped bore 106 in the pump stator 76.
• the stepped bore 106 has a first step 108 and a second step 110; the piston 102 has a reduced-diameter shoulder 112 which, in the position shown in FIG. 2, plunges into the stepped bore 106 up to behind the second step 110.
• the diameter of the shoulder 112 is substantially equal to the diameter of the stepped bore 106 after the second step 110; therefore the piston 102 forms a fluid-tight sealing seat 114 with the pump stator 76 with this shoulder.
• a spring 116 is pushed onto the shoulder 112, which is supported at one end on the piston 102 and at the other end on a support disk 118.
• the spring 116 is preferably designed as a plate spring assembly.
• the support disk 118 is supported in the position shown in FIG. 2 on the first step 108 of the stepped bore 106, the spring 116 being in a prestressed state.
• a securing ring 120 arranged on the circumference of the shoulder 112 prevents the spring 116 or the support disk 118 from being able to be removed from the piston 102 when the piston 102 is not installed.
• the locking ring 120 is not in contact with the second step 110 of the stepped bore 106, so that the piston 102 can be moved axially up to the sealing seat 114.
• a derivation 122 is formed between the first stage 108 and the second stage 110 transversely to the axis of the stepped bore 106 in the pump stator 76, which connects the stepped bore 106 to the locking and brake chamber 20 in a fluid-conducting manner.
• the piston 102 On its axially opposite side of the shoulder 112, the piston 102 bears against an intermediate piece 124, which is separated by a A plurality of spring elements 126 is axially biased.
• the spring elements 126 are supported on a stop piece 128 which is held on the housing 12 by means of a flange 130.
• the bias of the spring elements 126 on the intermediate piece 124 is greater in the position shown in FIG. 2 than the bias of the spring 116 on the piston 102.
• the piston 102 is therefore held by the spring element 126 in the position shown via the intermediate piece 124.
• the intermediate piece 124 encloses the commercially available throttle at the throttle point 90 and has a cross line 138 through which the fluid can get from the throttle point 90 into the locking and brake chamber 20.
• the transverse line 138 represents a lower flow resistance for the fluid than the throttle point 90.
• the intermediate piece 124 is guided radially in a bore 140 in the stop piece 128 and can be axially displaced therein.
• the intermediate piece 124 has an extension 142 on its circumference, which limits the axial movement of the intermediate piece 124 when the spring element 126 is compressed in the bore 140 by coming to rest against the stop piece 128.
• the stop piece 128 passes through the flange 130 and is screwed to it.
• the flange 130 is in turn screwed to the housing 12.
• the interfaces between the housing 12, the flange 130 and the stop piece 128 are sealed in a fluid-tight manner by seals 144, 146, 148.
• the stop piece 128 is axially penetrated by a bore 150 in which a pin 152 is axially displaceably mounted.
• the pin 152 is also sealed fluid-tight with a seal 154.
• the pin 152 rests with its left end in relation to FIG. 2 on the intermediate piece 124 and is biased at its right end by a switching plunger 156 of a switch 158 in this position by a spring 162.
• the switch 158 is fastened to a cover 160 which is screwed to the housing 12 and can assume three switch positions 1, 2, 3.
• the cover 160 ensures that the stop 128 and the flange 130 are not accessible from the outside without the cover 160 being removed.
• the switch 158 In the position shown in FIG. 2, the switch 158 is in the switching position 2.
• the piston 102 on the sealing seat 114 seals against the pump stator 76.
• the spring element 126 biases the piston 102 in this position.
• the pressure sensor device In the position described above and shown in FIG. 2, the pressure sensor device according to the invention is in its rest position.
• the pump 70 displaces fluid into the outlet channel 94, which flows further through the line 104, the throttle point 90 and the cross line 138 into the locking and braking chamber 20.
• the fluid flow is braked at the throttle point 90 so that the pump 70 fulfills the desired function as a hydrodynamic return brake.
• the commercial throttle at throttle point 90 is selected so that the braking power required for the corresponding drive head is achieved.
• the spring element 126 displaces the intermediate piece 124 and the piston 102 against the spring 116 again to the left in relation to FIG.
• the pressure sensor device is again in its rest position. While the movement from the rest position into the switching position 3, the stroke of the piston 102 is limited by the extension 142 on the intermediate piece 124.
• the sealing seat 114 between the shoulder 112 of the piston 102 and the pump stator 76 is retained during the entire stroke. The fluid cannot flow out except through the throttle point 90.
• the dynamic pressure remaining in the outlet duct 94 can be relieved manually.
• the cover 160 with the switch 158 is first removed from the housing 12.
• the switching plunger 156 is pushed into the switching position 1 by the spring 162.
• switch position 1 the rotary drive of the drive head is also switched off. It is guaranteed that the system cannot start up automatically during the following work.
• the stop piece 128 or the flange 130 is removed from the housing 12.
• the spring elements 126 are relieved and the spring 116 moves the piston 102 to the right in relation to FIG.
• This stroke takes place to such an extent that the sealing seat 114 is opened and the fluid accumulating in the outlet channel 94 can flow further through the discharge line 122 into the locking and brake chamber 20.
• the piston 102 can be removed from the stepped bore 106 and, for example, with the conventional throttle of the throttle point 90, the spring 116, the support disk 118 and the locking ring 120 as a unit getting cleaned.
• the drive head is only ready for operation again after the entire pressure sensor device has been properly installed and the cover 160 is fastened to the housing 12 with the switch 158.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Physics & Mathematics (AREA)
• Valves And Accessory Devices For Braking Systems (AREA)
• Details Of Reciprocating Pumps (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7885967

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (5)

Citations (5)

Family Cites Families (1)

• 1998
  • 1998-10-28 DE DE19849756A patent/DE19849756C2/de not_active Expired - Fee Related
• 1999
  • 1999-10-21 EP EP99953907A patent/EP1042586A1/de not_active Withdrawn
  • 1999-10-21 CA CA002316792A patent/CA2316792A1/en not_active Abandoned
  • 1999-10-21 CN CN99801930.5A patent/CN1287590A/zh active Pending
  • 1999-10-21 WO PCT/EP1999/007990 patent/WO2000025000A1/de not_active Application Discontinuation

Patent Citations (5)

Also Published As

Similar Documents

Legal Events