CA1193345A - Pump jack control apparatus - Google Patents
Pump jack control apparatusInfo
- Publication number
- CA1193345A CA1193345A CA000412302A CA412302A CA1193345A CA 1193345 A CA1193345 A CA 1193345A CA 000412302 A CA000412302 A CA 000412302A CA 412302 A CA412302 A CA 412302A CA 1193345 A CA1193345 A CA 1193345A
- Authority
- CA
- Canada
- Prior art keywords
- pump
- relay
- switch means
- cylinder
- closing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000012530 fluid Substances 0.000 claims abstract description 15
- 230000033001 locomotion Effects 0.000 claims description 8
- 230000001276 controlling effect Effects 0.000 claims 3
- 230000009849 deactivation Effects 0.000 claims 1
- 230000001133 acceleration Effects 0.000 description 4
- 230000007935 neutral effect Effects 0.000 description 2
- 241000242759 Actiniaria Species 0.000 description 1
- 241000003910 Baronia <angiosperm> Species 0.000 description 1
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
Classifications
-
- 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
- E21B43/126—Adaptations of down-hole pump systems powered by drives outside the borehole, e.g. by a rotary or oscillating drive
- E21B43/127—Adaptations of walking-beam pump systems
-
- 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
- F04B47/022—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps the driving mechanisms being situated at ground level driving of the walking beam
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The flow of hydraulic fluid to the pump of a pump jack and consequently the stroke of the polished rod is con-trolled by a pair of magnetic proximity limit switches mounted on the frame of the pump jack, and a magnet mounted on the polished rod. Closing of one switch by the magnet actuates a relay, which connects a battery to a solenoid for opening a valve through which hydraulic fluid is fed to one side of a double acting control cylinder. The control cylinder operates a pump, which feeds hydraulic fluid to one of a pair of oper-ating cylinders which move the walking beam, horsehead and polished rod. Closing of the other switch reverses the flow of hydraulic fluid to the control cylinder which causes the pump to feed hydraulic fluid to the other operating cylinder while taking oil from the first operating cylinder.
The flow of hydraulic fluid to the pump of a pump jack and consequently the stroke of the polished rod is con-trolled by a pair of magnetic proximity limit switches mounted on the frame of the pump jack, and a magnet mounted on the polished rod. Closing of one switch by the magnet actuates a relay, which connects a battery to a solenoid for opening a valve through which hydraulic fluid is fed to one side of a double acting control cylinder. The control cylinder operates a pump, which feeds hydraulic fluid to one of a pair of oper-ating cylinders which move the walking beam, horsehead and polished rod. Closing of the other switch reverses the flow of hydraulic fluid to the control cylinder which causes the pump to feed hydraulic fluid to the other operating cylinder while taking oil from the first operating cylinder.
Description
~ ~ 3~5 This invention relates to a control apparatus, and in par-ticular a control apparatus for a pump jack.
Canadian Patent Application Serial No. 366,803, filed by applicant on December 15, 1980, cliscloses a drive for a pump jack. There are presently avai].able mechanical and electrical systems for controlling pump jack dri.ves, i.e. for ensuring the precise turn around of the polished rod at the -top and bottom of the stroke. Examples o:E such systems are disclosed by U.S.
Patents Nos. 3,075,466, issued -to B. G. Agnew et al on January 29, 1963; 3,363,573, issued to W. S. Jaeger on January 16, 1969;
and 3,939,656, issued to Fl. A. Goldfein on February 24, 1976.
In general, the available mechanl.cal systems include complicated linkages, and the electrical systems employ sophisticated elec-tronics.
The object of the present i.nvention l.s to avoici the drawbacks o:E exi.StincJ systems by prov.iclincJ a relati.vely simple appara-tus for accurate control o~f the clr:ive of a pump jack.
Accorclingly, the present inverlt:ion relates to a con-trol apparatus for controll.ing the flow oE hydraulic flu:id from a pump in a pump jack of the t~pe :includincJ a samson post, a walking beam p;.votally mounted on the samson post for rotation around a horizontal axis, a horsehead on one end of the walking beam for driving connec-tion to a pump, said apparatus comprising first swi.-tch means for mounting on a fixed position on said pump jack; second switch means for mounting in a second fixed position ~ ~; s...
on said pump jack; actuating means for mounting on a movable element of said pump jack for elosing said firs-t switch means near one end of the walking beam stroke and ~or closiny said second switch rneans near the o-ther end of said walking beam stroke; circuit means incorporating said first and second switch means, said circuit means including relay means for closing by said first and second swi-teh means at the top and bottom of said wal]cing beam stroke; valve eontrol means for ac-tuation by sai.d relay means; cylinder means for controlling operation of said pump mechanism; and valve means for feeding hydrau.lie fluid -to said cylinder means, sa.id valve means being controlled by said valve control means in response to the closing of said first and second switch means, whereby closing o:E one o:E said first and seconcl switeh means causes movement of said polished rod in one direetion, and elosing of the other said swi.teh means eauses movement of said polished rocl in the opposite di.reetion.
The inventlon wi:Ll now be deser:ibecl :in CJre~ter detail with referenee to the aecompa.nyincJ clraw.i.rlcJs, wh:ieh illustrate a preEerrecl embodiment of -the invent.ion, and wherein:
E`igure 1 is a side eLevatl.on view of a pump jaek and drive of the type on whieh -the eontrol apparatus of the present invention is used;
E~igure 2 is a eross-sectional view taken generally along line II II of Figure l;
Figure 3 is a sehematie elevation view of switches and a switch actuator used in the appara-tus of -the present inven-tion;
Figure 4 is a circuit diagram of a control circuit for use in the apparatus of the present invention; and Figure 5, which appears on the second sheet of draw-ings, is a schematic longitudinal sectional view of a hydraulic control cylinder for use in -the apparatus of the present inven-tion.
With reference to Figures 1 and 2, a conven~ional pump jack includes a walki.ng beam 1 pivotally mounted on the top of a samson post 2 for rotation around a horizontal axis defined by a sadclle bearing 3. The samson post 2 .includes four inelined legs 4 extendi.n~ upwardly Erom a base 5, a top plate 6, and crossbars 7 e~-tencling between the legs 4 at the :Eront and rea.r ends oE the post 2. A counterweight 8 is mounted on the rear end 9 of the walking beam, and a horsehead 10 ls mounted on the :Eront end 11 oE such b~am. ~ wire line assembly o:r wire :rope bridal 12 :is eonnected at one end to the horsehead :I.0 and at the other end to a p~m~p meehanism, incluc1ing pol:i.shed rod 13. The briclal 12 and rod 13 are intercorlnected by a eonnector 14.
Usually, -the polishecl rod 13 ree:iprocates a sueker rod or pump rod associated with a downhole pUlTlp (not shown).
The walking beam 1 is driven by hydraul.ic cylinders 15 and 16 connected to -the rear and front ends 9 and 11, re-spectively of the walking beam. The bottom ends of the hydraulic ~3~
cylinders 15 and 16 are pivotally connected to an I-beam 17 by clevises 18. The I-beam 17 is supported by the crossbars 7.
Piston rods 19 extend upwardly from the top ends of the cylinders 15 and 16 to the walking beam 1. The top ends of the piston rods 19 are pivotally connected to the walking beam 1 by clevises 20.
The hydraulic cylinders 15 and 16 are operated by a hydraulic pump 21, which is driven by a prime mover in the form of a mo-tor 22. Hydraulic fluid is stored in hydraulic ~luid reservoir 23. The pump 21, -the motor 22 and -the reservoir 23 are mounted on the rear end of the base 5. A V-belt 2~ passes around pulleys 25 on the motor 22 and the pump 21, respectively.
The pump 21 is controlled by a pump control lever 26 (:Figure 5). Movement of the lever 26 i.n one direction results in -the flow of fluid -to one cyl.in.der 15, and movemen-t of such lever in the other d:irection causes :Elow o.E flu:id to the other cylinder l.6. Movement o.E the lcver 26 is controlled by the apparatus o.E the presellt .invelltion. Such apparatus will now be describecl reEerrin~ :Eirst to ~tLcJure 3.
rl~he apparatus lnclucles a pair o.E swi-tches Sl and S2 mountec~ on a vertically oriented bar 27. The switches are slidable on the bar 27, so -that the vertical positions thereoE
can readily be adjusted. The switches Sl and S2 are locked in position by bolts 28. The bar 27 is mounted on a fixed portion of the pump jack such as the I-beam 17.
The swi-tches Sl and S2 are normally open, magnetieal-ly actuated proximity switches for ac-tuation by a magnet 30, which is moun-ted on -the polished rod 13 or on another movable part of the pump ~ack which moves in -the same manner as the polished rod 13. The switches Sl and S2 may also be mechanical-ly actuated, i.e. microswi-tches actuated by a lug or bar instead of -the magne-t 30. Referring to Figure 4 of the drawings, the switches Sl and S2 are used to actua-te relays 31 and 32, respectively. When the magnetic field of the magnet 30 causes closing of the switch Sl, cur:rent is supp].ied to terminal 7a of the relay 31 c:Loslng con-taet la wl-th eontact 4a, and contact 2a wi.th contact 6a. The eontaet la is eonneeted to the positive terminal o.E a 12-volt battery 33 by means o:E an ON/OFF switeh S7. Curren-t Elows through the contacts la and 4a to a terminal 7a. Thus, power is introdueed into a rel.ay~35 of the relay 31, so that the .~elay~35 remains :I.n the ~ctuated eond:lt:Lon. In sueh eond:Ltion, no eurrerlt flows to a terminal 7e oE a eo:Ll 35 wh:ieh i.s eonneeted to a eontaet 3a oE the rel;~y 3.1. Contaets 2e and 5e o.E the relay 35 are ln the eLose~ eondlt:l.on, allow:LncJ eurrent to f:Low to a solenoicl 36. Power to the soleno:Ld 36 causes the pump jaek to move downwardly (i.n the manner de:ser:Lbed herein-a:E-ter) until the .Eield oE the magnet 30 closes the switeh S2.
When the magnet 30 eauses the switehes to elose, power is supplied to a terminal 7b of the relay to aetuate a eoil 37 in the relay 32. This aetion eloses eontaets lb-4b and 2b-6b ~,, ~ . I
3~
of -the relay 32, while breaking con-tact lb-3b and 2b 5b. It will be noted -that in each of the relays, the contac-ts 1-3 and
Canadian Patent Application Serial No. 366,803, filed by applicant on December 15, 1980, cliscloses a drive for a pump jack. There are presently avai].able mechanical and electrical systems for controlling pump jack dri.ves, i.e. for ensuring the precise turn around of the polished rod at the -top and bottom of the stroke. Examples o:E such systems are disclosed by U.S.
Patents Nos. 3,075,466, issued -to B. G. Agnew et al on January 29, 1963; 3,363,573, issued to W. S. Jaeger on January 16, 1969;
and 3,939,656, issued to Fl. A. Goldfein on February 24, 1976.
In general, the available mechanl.cal systems include complicated linkages, and the electrical systems employ sophisticated elec-tronics.
The object of the present i.nvention l.s to avoici the drawbacks o:E exi.StincJ systems by prov.iclincJ a relati.vely simple appara-tus for accurate control o~f the clr:ive of a pump jack.
Accorclingly, the present inverlt:ion relates to a con-trol apparatus for controll.ing the flow oE hydraulic flu:id from a pump in a pump jack of the t~pe :includincJ a samson post, a walking beam p;.votally mounted on the samson post for rotation around a horizontal axis, a horsehead on one end of the walking beam for driving connec-tion to a pump, said apparatus comprising first swi.-tch means for mounting on a fixed position on said pump jack; second switch means for mounting in a second fixed position ~ ~; s...
on said pump jack; actuating means for mounting on a movable element of said pump jack for elosing said firs-t switch means near one end of the walking beam stroke and ~or closiny said second switch rneans near the o-ther end of said walking beam stroke; circuit means incorporating said first and second switch means, said circuit means including relay means for closing by said first and second swi-teh means at the top and bottom of said wal]cing beam stroke; valve eontrol means for ac-tuation by sai.d relay means; cylinder means for controlling operation of said pump mechanism; and valve means for feeding hydrau.lie fluid -to said cylinder means, sa.id valve means being controlled by said valve control means in response to the closing of said first and second switch means, whereby closing o:E one o:E said first and seconcl switeh means causes movement of said polished rod in one direetion, and elosing of the other said swi.teh means eauses movement of said polished rocl in the opposite di.reetion.
The inventlon wi:Ll now be deser:ibecl :in CJre~ter detail with referenee to the aecompa.nyincJ clraw.i.rlcJs, wh:ieh illustrate a preEerrecl embodiment of -the invent.ion, and wherein:
E`igure 1 is a side eLevatl.on view of a pump jaek and drive of the type on whieh -the eontrol apparatus of the present invention is used;
E~igure 2 is a eross-sectional view taken generally along line II II of Figure l;
Figure 3 is a sehematie elevation view of switches and a switch actuator used in the appara-tus of -the present inven-tion;
Figure 4 is a circuit diagram of a control circuit for use in the apparatus of the present invention; and Figure 5, which appears on the second sheet of draw-ings, is a schematic longitudinal sectional view of a hydraulic control cylinder for use in -the apparatus of the present inven-tion.
With reference to Figures 1 and 2, a conven~ional pump jack includes a walki.ng beam 1 pivotally mounted on the top of a samson post 2 for rotation around a horizontal axis defined by a sadclle bearing 3. The samson post 2 .includes four inelined legs 4 extendi.n~ upwardly Erom a base 5, a top plate 6, and crossbars 7 e~-tencling between the legs 4 at the :Eront and rea.r ends oE the post 2. A counterweight 8 is mounted on the rear end 9 of the walking beam, and a horsehead 10 ls mounted on the :Eront end 11 oE such b~am. ~ wire line assembly o:r wire :rope bridal 12 :is eonnected at one end to the horsehead :I.0 and at the other end to a p~m~p meehanism, incluc1ing pol:i.shed rod 13. The briclal 12 and rod 13 are intercorlnected by a eonnector 14.
Usually, -the polishecl rod 13 ree:iprocates a sueker rod or pump rod associated with a downhole pUlTlp (not shown).
The walking beam 1 is driven by hydraul.ic cylinders 15 and 16 connected to -the rear and front ends 9 and 11, re-spectively of the walking beam. The bottom ends of the hydraulic ~3~
cylinders 15 and 16 are pivotally connected to an I-beam 17 by clevises 18. The I-beam 17 is supported by the crossbars 7.
Piston rods 19 extend upwardly from the top ends of the cylinders 15 and 16 to the walking beam 1. The top ends of the piston rods 19 are pivotally connected to the walking beam 1 by clevises 20.
The hydraulic cylinders 15 and 16 are operated by a hydraulic pump 21, which is driven by a prime mover in the form of a mo-tor 22. Hydraulic fluid is stored in hydraulic ~luid reservoir 23. The pump 21, -the motor 22 and -the reservoir 23 are mounted on the rear end of the base 5. A V-belt 2~ passes around pulleys 25 on the motor 22 and the pump 21, respectively.
The pump 21 is controlled by a pump control lever 26 (:Figure 5). Movement of the lever 26 i.n one direction results in -the flow of fluid -to one cyl.in.der 15, and movemen-t of such lever in the other d:irection causes :Elow o.E flu:id to the other cylinder l.6. Movement o.E the lcver 26 is controlled by the apparatus o.E the presellt .invelltion. Such apparatus will now be describecl reEerrin~ :Eirst to ~tLcJure 3.
rl~he apparatus lnclucles a pair o.E swi-tches Sl and S2 mountec~ on a vertically oriented bar 27. The switches are slidable on the bar 27, so -that the vertical positions thereoE
can readily be adjusted. The switches Sl and S2 are locked in position by bolts 28. The bar 27 is mounted on a fixed portion of the pump jack such as the I-beam 17.
The swi-tches Sl and S2 are normally open, magnetieal-ly actuated proximity switches for ac-tuation by a magnet 30, which is moun-ted on -the polished rod 13 or on another movable part of the pump ~ack which moves in -the same manner as the polished rod 13. The switches Sl and S2 may also be mechanical-ly actuated, i.e. microswi-tches actuated by a lug or bar instead of -the magne-t 30. Referring to Figure 4 of the drawings, the switches Sl and S2 are used to actua-te relays 31 and 32, respectively. When the magnetic field of the magnet 30 causes closing of the switch Sl, cur:rent is supp].ied to terminal 7a of the relay 31 c:Loslng con-taet la wl-th eontact 4a, and contact 2a wi.th contact 6a. The eontaet la is eonneeted to the positive terminal o.E a 12-volt battery 33 by means o:E an ON/OFF switeh S7. Curren-t Elows through the contacts la and 4a to a terminal 7a. Thus, power is introdueed into a rel.ay~35 of the relay 31, so that the .~elay~35 remains :I.n the ~ctuated eond:lt:Lon. In sueh eond:Ltion, no eurrerlt flows to a terminal 7e oE a eo:Ll 35 wh:ieh i.s eonneeted to a eontaet 3a oE the rel;~y 3.1. Contaets 2e and 5e o.E the relay 35 are ln the eLose~ eondlt:l.on, allow:LncJ eurrent to f:Low to a solenoicl 36. Power to the soleno:Ld 36 causes the pump jaek to move downwardly (i.n the manner de:ser:Lbed herein-a:E-ter) until the .Eield oE the magnet 30 closes the switeh S2.
When the magnet 30 eauses the switehes to elose, power is supplied to a terminal 7b of the relay to aetuate a eoil 37 in the relay 32. This aetion eloses eontaets lb-4b and 2b-6b ~,, ~ . I
3~
of -the relay 32, while breaking con-tact lb-3b and 2b 5b. It will be noted -that in each of the relays, the contac-ts 1-3 and
2-5 are normally closed, and -the contacts 1-4 and 2-6 are normally open. The ground for the relay 31 is connected -through terminal 3a to -the con-tacts lb and 3b -to the ground for the re-lay 32. The breaking of the circuit involving contacts lb and 3b causes a breakdown of the relay 31, thus breaking contacts la-4a and 2a-6a, making contacts la-3a and 2a-5a. The ground line for the relay 32 is connected through terminals 8b, 2a and 6a to the ground. Since contact be-tween the -terminals 2a and 6a is broken when power is applied to the terminal 7b, the switch S2 cannot aEfect -the coil 32 unti] -the swi-tch Sl has again been closed. With -the relay 31 in the broken down condition, power is supplied through contacts la and 3a, and terminal 7c oE the relay 35, coil 3~ of the re].ay 35 to close eontacts 2c-5c and disconnect contaets 2c-6c. 'rhus, eurrent flows to a seeond solenoid 39 throucJh contacts 2c ancl 5c, and the direction oE
movement oE the pol:ished roci 13 ls reversed, :i.e. the polished rod moves upwardly.
The solenolcls 36 ancl 39 are connected to a Eour-way spool valve 40 (Fi~ure 5), which opera-tes a double ac-ting cyllnder 41. The double actiny cylinder 41 is defined by a hollow cylinder, closed at each oE its ends 42 and 43, with a central partition 44 dividing the cylinder into a pair of chambers 45 and 46. The chambers 45 and 46 are connected to the ~3~
valve 40 by lines 47 and 48, respectively. The lines 47 and 48 contain valves 49 and 50, respec-tively. A piston Sl is slidably mounted in ~he chamber ~5, and fluid is introduced into the chamber 45 on either side of the piston 51 through the lines 47 and 48. The valve 40 opens the line 47 or 48 to a line 52 con-nected to a source of hydraulic fluid under pressure (no-t shown) or to a hydraulic fluid reservoir (not shown) via line 53. A
piston rod 54 is connec-ted -to the piston 41 and extends through the partitlon 44 and the end wall 43 of -the cylinder 41 -to the pump control lever 26. ~ Eirst adjustable stop 55 is provlded on the rod 54 between the end wall 43 oE -the cylinder and the lever 26. A second adjustab].e stop 56 is provided on the piston rod 54 in the chamber 46 oE the cylinder 41. The posltions of the stops 55 and 56 can be chancted to adjust the stroke of the piston 51 in either direction. The lever 26 is connected to the variable displacement pump 21. The output and dlrection of oil Elow throucJh the pump 2l. are cJoverrlccl by the dlrection and decJree oE cleElectlorl o~ the cont~ol lever 26. 'rhe clirection arld deyree oE deEIection of the control. lever are determined by acljustincJ
the stops 55 and 56 on the pistorl rod 54. The stop 55 controls the speed oE the pump jack when travellincJ upwardly, and the stop 56 controls the speed of the pump jack and polished rod 13 when travellin~ downwardly. The acceleration of the rod 13 at the turn around points in the stroke are determined by the time required for the cylinder rod 54 to travel the distance between ~3~
the stops 55 and 56. The acceleration time is adjusted by metering the oil flow into the cylinder ~l using -the valves 49 and 50. The valve ~9 con-trols acceleration at the bottom turn around, and -the valve 50 con-trols acceleration at the top -turn around. A spring return system (no-t shown) is used to re-turn -the piston 51 to the neutral position with respect -to the lever 26.
Referring again to Figure ~ ~f the drawings, a safety shut-down system is provided, inclu~ding saEety switches S3, S4, S5 and S6. The swi-tches are normally open and are connected in parallel to terminal 7d oE a relay 60. Closing of any of the safety swi-tches applies power to the terminal 7d, causinc3 closing of contacts ld-4d and 2c1-6d, while breaking contaet betwet-~n contaets ld-3d and 2d-~d. Thus, eurrent Erom -the hattery 33 Elows through contacts ld and 3d to the terminal 7d, and the eoil 61 of the relay 60 remains cnergl~zetl to hoLd open eont~ets 2d and ~d. Power to the eontae~ 2e ol thelreLay~35 is :Lnter-ruptt-~d, and tilus no powt-~r Ls suppLled to elther o tht solt-~noitls 36 and 39. Thus, :L any oE tht sa;Lety swlteht-~s S3-S6 :Ls aetu-ated, the pUIllp jae]c stops. ~rhe saE~ty swltches S3 and S6 are commonly part oE cireuits :i.nvolvlng tht-~ hydraulie system. For examples, the safety switches would be used to de-tect exeess pressure in the hydraulie system, excess pressure in flow lines, over travel oE the switching system and low hydraulie fluid. If no eurrent flows to either of the solenoids 36 and 39, the valve
movement oE the pol:ished roci 13 ls reversed, :i.e. the polished rod moves upwardly.
The solenolcls 36 ancl 39 are connected to a Eour-way spool valve 40 (Fi~ure 5), which opera-tes a double ac-ting cyllnder 41. The double actiny cylinder 41 is defined by a hollow cylinder, closed at each oE its ends 42 and 43, with a central partition 44 dividing the cylinder into a pair of chambers 45 and 46. The chambers 45 and 46 are connected to the ~3~
valve 40 by lines 47 and 48, respectively. The lines 47 and 48 contain valves 49 and 50, respec-tively. A piston Sl is slidably mounted in ~he chamber ~5, and fluid is introduced into the chamber 45 on either side of the piston 51 through the lines 47 and 48. The valve 40 opens the line 47 or 48 to a line 52 con-nected to a source of hydraulic fluid under pressure (no-t shown) or to a hydraulic fluid reservoir (not shown) via line 53. A
piston rod 54 is connec-ted -to the piston 41 and extends through the partitlon 44 and the end wall 43 of -the cylinder 41 -to the pump control lever 26. ~ Eirst adjustable stop 55 is provlded on the rod 54 between the end wall 43 oE -the cylinder and the lever 26. A second adjustab].e stop 56 is provided on the piston rod 54 in the chamber 46 oE the cylinder 41. The posltions of the stops 55 and 56 can be chancted to adjust the stroke of the piston 51 in either direction. The lever 26 is connected to the variable displacement pump 21. The output and dlrection of oil Elow throucJh the pump 2l. are cJoverrlccl by the dlrection and decJree oE cleElectlorl o~ the cont~ol lever 26. 'rhe clirection arld deyree oE deEIection of the control. lever are determined by acljustincJ
the stops 55 and 56 on the pistorl rod 54. The stop 55 controls the speed oE the pump jack when travellincJ upwardly, and the stop 56 controls the speed of the pump jack and polished rod 13 when travellin~ downwardly. The acceleration of the rod 13 at the turn around points in the stroke are determined by the time required for the cylinder rod 54 to travel the distance between ~3~
the stops 55 and 56. The acceleration time is adjusted by metering the oil flow into the cylinder ~l using -the valves 49 and 50. The valve ~9 con-trols acceleration at the bottom turn around, and -the valve 50 con-trols acceleration at the top -turn around. A spring return system (no-t shown) is used to re-turn -the piston 51 to the neutral position with respect -to the lever 26.
Referring again to Figure ~ ~f the drawings, a safety shut-down system is provided, inclu~ding saEety switches S3, S4, S5 and S6. The swi-tches are normally open and are connected in parallel to terminal 7d oE a relay 60. Closing of any of the safety swi-tches applies power to the terminal 7d, causinc3 closing of contacts ld-4d and 2c1-6d, while breaking contaet betwet-~n contaets ld-3d and 2d-~d. Thus, eurrent Erom -the hattery 33 Elows through contacts ld and 3d to the terminal 7d, and the eoil 61 of the relay 60 remains cnergl~zetl to hoLd open eont~ets 2d and ~d. Power to the eontae~ 2e ol thelreLay~35 is :Lnter-ruptt-~d, and tilus no powt-~r Ls suppLled to elther o tht solt-~noitls 36 and 39. Thus, :L any oE tht sa;Lety swlteht-~s S3-S6 :Ls aetu-ated, the pUIllp jae]c stops. ~rhe saE~ty swltches S3 and S6 are commonly part oE cireuits :i.nvolvlng tht-~ hydraulie system. For examples, the safety switches would be used to de-tect exeess pressure in the hydraulie system, excess pressure in flow lines, over travel oE the switching system and low hydraulie fluid. If no eurrent flows to either of the solenoids 36 and 39, the valve
3~
40 returns -to the neutral position, -thereby opening both of -the chambers 45 and 46 to the line 53, i.e~ to the reservoir.
Because piston 51 of the cylinder 4] is spring-centered, the piston returns to the central position. Thus, -the pump control lever 26 is also returned to -the central position, causing the pump jack to stop.
40 returns -to the neutral position, -thereby opening both of -the chambers 45 and 46 to the line 53, i.e~ to the reservoir.
Because piston 51 of the cylinder 4] is spring-centered, the piston returns to the central position. Thus, -the pump control lever 26 is also returned to -the central position, causing the pump jack to stop.
Claims (6)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A control apparatus for controlling the flow of hydraulic fluid from a pump in a pump jack of the type including a samson post, a walking beam pivotally mounted on the samson post for rotation around a horizontal axis, a horsehead on one end of the walking beam for driving connection to a pump, said apparatus comprising first switch means for mounting on a fixed position on said pump jack; second switch means for mounting in a second fluid position on said pump jack; actuating means for mounting on a movable element of said pump jack for closing said first switch means near one end of the walking beam stroke and for closing said second switch means near the other end of said walking beam stroke; circuit means incorporating said first and second switch means, said circuit means including relay means for closing by said first and second switch means, at the top and bottom of said walking beam stroke; valve control means for actuation by said relay means; cylinder means for controlling operation of said pump and valve means for feeding hydraulic fluid to said cylinder means, said valve means being controlled by said valve control means in response to the closing of said first and second switch means, whereby closing of one of said first and second switch means causes movement of said polished rod in one direction, and closing of the other said switch means causes movement of said polished rod in the opposite direction.
2. A control apparatus according to claim 1, wherein said first and second switch means are magnetic proximity switches, and said actuating means is a magnet mounted on said polished rod.
3. A control apparatus according to claim 1, wherein said relay means includes a first relay for actuation by said first switch means, and a second relay for actuation by said second switch means, said first and second relays being inter-connected, whereby actuation of one said relay results in the deactivation of the other said relay.
4. A control apparatus according to claim 3, wherein said valve control means includes a first solenoid for actuation by said first relay, and a second solenoid for actuation by said second relay.
5. A control apparatus according to claim 4, wherein said cylinder means includes a double acting cylinder for con-trolling operation of said pump.
6. A control apparatus according to claim 5, including stop means associated with said cylinder for limiting the move-ment of said cylinder and consequently the stroke of said polished rod.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000412302A CA1193345A (en) | 1982-09-27 | 1982-09-27 | Pump jack control apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000412302A CA1193345A (en) | 1982-09-27 | 1982-09-27 | Pump jack control apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1193345A true CA1193345A (en) | 1985-09-10 |
Family
ID=4123669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000412302A Expired CA1193345A (en) | 1982-09-27 | 1982-09-27 | Pump jack control apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1193345A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3170968A1 (en) * | 2015-11-20 | 2017-05-24 | Weatherford Technology Holdings, LLC | Well pumping system and method |
| US9903187B2 (en) | 2015-08-05 | 2018-02-27 | Weatherford Technology Holdings, Llc | Hydraulic pumping system with enhanced piston rod sealing |
| US10167865B2 (en) | 2015-08-05 | 2019-01-01 | Weatherford Technology Holdings, Llc | Hydraulic pumping system with enhanced piston rod sealing |
| US10344573B2 (en) | 2016-03-08 | 2019-07-09 | Weatherford Technology Holdings, Llc | Position sensing for wellsite pumping unit |
-
1982
- 1982-09-27 CA CA000412302A patent/CA1193345A/en not_active Expired
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9903187B2 (en) | 2015-08-05 | 2018-02-27 | Weatherford Technology Holdings, Llc | Hydraulic pumping system with enhanced piston rod sealing |
| US10167865B2 (en) | 2015-08-05 | 2019-01-01 | Weatherford Technology Holdings, Llc | Hydraulic pumping system with enhanced piston rod sealing |
| US10619464B2 (en) | 2015-08-05 | 2020-04-14 | Weatherford Technology Holdings, Llc | Hydraulic pumping system with detection of fluid in gas volume |
| US10760388B2 (en) | 2015-08-05 | 2020-09-01 | Weatherford Technology Holdings, Llc | Slant mounted hydraulic pumping system |
| US11098708B2 (en) | 2015-08-05 | 2021-08-24 | Weatherford Technology Holdings, Llc | Hydraulic pumping system with piston displacement sensing and control |
| EP3170968A1 (en) * | 2015-11-20 | 2017-05-24 | Weatherford Technology Holdings, LLC | Well pumping system and method |
| US10344573B2 (en) | 2016-03-08 | 2019-07-09 | Weatherford Technology Holdings, Llc | Position sensing for wellsite pumping unit |
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| MKEC | Expiry (correction) | ||
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