US2341195A

US2341195A - Hydraulically reciprocable pump mechanism

Info

Publication number: US2341195A
Application number: US349842A
Authority: US
Inventors: Ernest J Svenson
Original assignee: Odin Corp
Current assignee: Babcock and Wilcox Co; Odin Corp
Priority date: 1940-08-02
Filing date: 1940-08-02
Publication date: 1944-02-08
Anticipated expiration: 1961-02-08

Description

Feb. 8, 1944. E. .1. SVENSON v HYDRAULICALLY RECIPROCABLE PUMP MECHANISM Filed Aug. 2, 1940 5 Sheets-Sheet 1 1. Q IIIII VWJ Fil Feb. 8, 1944. E. J. SVENSON HYDRAULICALLY RECIPROCABLE PUMP MECHANISM Filed Aug. 2, 1940 5 Sheets-Sheet 2 506726022 a m a% Feb. 8, 1944. E. J. SVENSON HYDRAULIGALLY RECIPROCABLE PUMP MECHANISM INVENTOR.

uezzesarw %0@ 4 04 5 Sheets-Sheet 4 jivzasf 9 0 l 2 mm A. M 4% d 5 e i m M 7 row. J

Feb, 3, 1944. E. .1. SVENSON HYDRAULICALLY RECIPROCABLE PUMP MECHANISM 5 sheetsfsheet 5 Filed Aug. 2, 1940 INVENTOR.

Patented Feb. 8, 1944 HYDRAULICALLY mesne assignments,

1i Claims.

This invention relates generally to hydraulically reciprocable pump mechanisms and more particularly to pump mechanisms known generally in the art as deep well pumps.

I am familiar with a number of conventional deep well pump. devices now available to the public wherein power actuators are employed in RECIPROCABLE PUMP MECHANISM Ernest J. Svenson, Rockford, 111., assignor, by

to Odin Corporation. Chlcago, 111., a corporation of Illinois Application August 2, 1940, Serial No. 549,842

I'he invention also contemplates a pump actuator unit which may be coupled with conventional suckerrodswithout requiring rearraising water and the like within a drop pipe. A

number of these conventional devices require complete reorganization and reconstruction of the well pump proper, that is, the usual reciprocating piston located in the vicinity of the lower end of the well casing. For example, centrifugal pumps have been employed in place of the conventional reciprocating pump piston, making it necessary to drive this centrifugal pump through some means such as a shaft or rod extending downwardly within thedroplpipe. Experience has shown, however, that conventional reciprocable type well pumps have proven highly emcient, provided that suitable actuating means is used to impart reciprocation to the pump sucker rod. It is, therefore, one oi'the important objects or the present invention to provide a power operated pumping mechanism which incorporates as one element thereof a rangement or reconstruction oi the pump parts connected with the sucker rods, as, for example, the reciprocable pump proper located toward the bottom of the drop pipe, and the upper ex 'tremities of both the drop pipe and the well casing. To this end I propose to provide a unit which is adaptable for use with drop pipes and well casings of varied diameters.

The invention also contemplates a pump actuator unit wherein an electric motor, a fluid propelling mechanism or pump and a hydraulic actuator connected therewith are housed in compact relationship and are readily accessible for adjustment, repair or replacement.

The foregoing and numerous other objects and advantages will be more apparent from the followingdetailed description when considered in connection with the accompanying drawings,

' wherein:

reciprocable type of pump, as, for example, the

well-known .reciprocable piston type pump which has been used for many years in deep well pump installations.

. More specifically, the invention contemplates in combination with the aforesaid highly emcient reciprocable plunger or piston pump, a

hydraulic actuator mechanism of extremely simple and practical design which will serve to actuate said pump with the utmost efflciency.

:It is also an object of the present invention to provide a mechanism of the type set forth above wherein the well casing and associated parts will be absolutely free from lubricant or the like and to this end I propose to so arrange the pump actuator and the source of fluid pressure supply as to completely isolate these parts from the well casing.

A further object of the present invention is to provide a hydraulic actuator for shifting a part such as a reciprocable deep well pump piston which is completelysell-contained, requiring no external element for controlling the reciprocation of the actuator.

Another object of the present invention is to provide pumping mechanism of the type referred to above wherein the parts are readily detachable for servicing the well pump proper with aminimum amount of effort and skill.

Fig. 1 is an elevational view of a pumping .mechanism incorporating features of the present invention, the lower portions of the well casing and drop pipe. as well as the pump proper, being broken away for the purpose of more clearly disclosing parts otherwise hidden;

Fig. 2 is an enlarged fragmentary vertical sectional view taken substantially along th line 2-2 01' Fig. 1. such parts as the hydraulic actuator, gear pump and motor housing being shown in elevation;

Fig. 3 is an enlarged fragmentary sectional view taken substantially along the line 3-3 of Fig. 4, disclosing the hydraulic actuator for shifting the sucker rod and the gear pump associated therewith:

Fig. 4 is a plan view of the structure as shown in Fig. 3, said view being taken substantially along the line 4-4 of Fig. 3;

Fig. 5 is a vertical sectional view of the hydraulic actuator disclosed in Fig. 3, showing said actuator in its lowermost position;

Fig. 6 is a fragmentaryvertical sectional view of the actuator structure of Fig. 3, said view being taken substantially alongthe line 6-6 of' Fig. 3;

Fig. 7 is a fragmentary vertical sectional view of the hydraulic actuator shown in Fig. 3, said.

view being taken substantially along the line "l-i of Fig. 3;

Fig. 8 is a horizontal transverse sectional view' taken substantially along the line 8-8 of Fig. 3; Fig. 9 is a vertical'sectional view of a hydraulic actuator oi modified design. the shiitable cylinder structure of the actuator being shown in its uppermost position;

Fig. is a fragmentary vertical sectional view similar to Fig. 9, disclosing the cylinder structure of the hydraulic actuator in its lowermost position;

Fig. 11 is a horizontal sectional view taken substantially along the line ll-il of Fig. 9;

Fig. 12 is a horizontal sectional view taken substantially along the line l2-l2 of Fig. 9;

Fig. 13 is a transverse sectional view taken substantially along the line l3l3 of Fig. 9;

Fig. 14 discloses an expanded or "rolled out" sectional view of the actuator piston disclosed in Figs. 9 to 13, inclusive; and

Figs. 15 to 18, inclusive, constitute sectional disclosures of the pistons taken at Various points in order to more clearly disclose the arrangements of the fluid passage-ways therein, the valve members being removed for purposes of cleamess, these views being substantially as follows: Fig. 15 is taken substantially along the line iii-l5 of Fig. 13; Fig. 16 is taken substantially along the line lG--l8 of Fig. 13; Fig. 1'7 is taken substantially along the line "-11 of Fig. 12; and Fig. 18 is taken substantially along the line l8l8 of Fig. 11.

Referring now to the drawings more in detail. wherein like numerals have been employed to designate similar parts throughout the various figures, it will be seen that the invention conward stroke of the piston, fluid within the cyltemplates a pumping mechanism comprising an upper structure which I shall refer to as the power and actuator mechanism designated generally by the numeral 20. This power and actuator mechanism 20 presents a unitary or selfcontained structure which may be mounted as a unit immediately above and in operative association with parts of a conventional deep well pump such as a conventional drop pipe 22 and a well casing 24. It will be seen that this power and actuator unit 20 includes a frame or housing 26 having a flange 28 adapted to rest upon the upper surface of a well platform 30, this platform in turn being supported by any suitable mounting such as the concrete base 32 shown in Fig. l. The concrete base is supported by the upper surface of the ground or soil, into which the aforesaid drop pipe 22 and well casing 24 extend. It will be noted that a skirt or flange 34 is formed integral with and extends downwardly from the frame or housing 26, Fig. 2, so as to enclose the upper portion of the well casing 24. The drop pipe has a threaded connection with a suitable adapter bushing 36 which is externally threaded to engage a complementary internal threaded portion of the frame or housing 25. I propose to have the internal diameter of the skirt or depending flange 34 such as to accommodate well casings of varied diameters, and I also propose to use adapter bushings of varied internal diameters to accommodate various sizes of drop pipes.

Before entering into a detailed description of the power and actuator devices within the unit 20, I shall refer briefly to the conventional well pump proper designated generally by the numeral 38 in Fig. 1. This conventional well pump device 38 comprises the usual casing or cylinder 40 which is secured to the lower extremity of the drop pipe 22. A piston 42 is reciprocated within the cylinder 40 in response to movement imparted to the usual sucker rod 44. The check valve 46 permits fluid to enter the inder during this downward movement oi. the piston passing through the usual check valve, not

shown. The upward movement-of the piston 42 causes fluid to be raised within the drop pipe 22 and delivered to a chamber 48 positioned at the mouth of the drop pipe 22, as clearly shown in Fig.2.

One of the important features of the present invention resides in the mechanism for imparting reciprocating movement to the sucker rod 44 and this mechanism includes a hydraulic actuator device designated generally by the numeral 50, Figs. 2 to 8, inclusive. This hydraulic actuator device or mechanism 50 includes a vertically reciprocable cylinder structure 52 and a fixed or immovable piston structure 54, which is formed integral with a piston rod 58. The

piston rod 56 is secured at its upper extremityv to a base or mounting member 58 as clearly shown in Fig. 3, a shoulder or flange 60 being provided upon the piston rod 56 which is sealingly clamped against a suitable gasket 62. The upper extremity of the shiitable actuator cylinder 52 includes a suitable cap 64 which is threaded within the internal wall of the cylinder and is clamped against suitable sealing material 66. Packing glands 68 carried by the cap '64 surround the piston rod 56 and are secured in proper position by means of an adjustable clampingnut l0. cylindera62 includes a cap or end member I2 which may be welded at 14 to the cylindrical wall structure of the actuator. Formed integral with and depending from the cap or plate 12 is a suitable connector rod 16 which is threaded for the purpose of being coupled either directly or indirectly with the sucker rod 44, as will presently appear. In the disclosed embodiment an indirect coupling of the threaded member 16 is made with the upper extremity of the sucker rod 44 through the agency of an intermediate connector rod 18, Fig. 2. This rod 18 is enlarged at its upper extremity and threaded to receive the lower end of the member 18 and is threaded at its lower extremity to receive a suitable sucker rod coupling which is indicated in it .would be possible to directly couple the J threaded member 16 with the sucker rod 44.

Referring again to the hydraulic actuator mechanism 50, attention is directed to the manner in which pressure fluid is supplied thereto. In this connection it will be observed that an electric motor 84 is disposed above and centrally with respect to the frame 26, said motor being mounted along the upper margin and flange or skirt 86 which forms a part of the mounting member or base 58. The shaft 88 of the motor 84 extends downwardly through a suitable bearing 90 provided in the base 58, the lower extremity of said shaft extending below the base 58 and into a fluid pressure generating mechanism or gear pump designated generally by the numeral 92. The essential details of construction of this gear pump 92 are disclosed in my issued Patents Nos, 1,912,737 and 1,912,738 and, therefore, a de- The lower extremity of the assures i3 carried by a shaft I and the gear 88 being driven directly from. the motor shaft 88. The gear pump 92 is secured in place by suitable bolts I02,

a threaded cap I04 serving to close the opening presented immediately beneath the lower extremity of the motor shaft 88. I

Fluid such as oil is drawn into the pump 92 through a pipe line or conduit I06, Fig. 2, which extends within an oil reservoir I08 contained within and forming a part of the frame 26. The lower extremity of the intake pipe I06 is hellshaped and cut off at an angle, as shown in Fig.

2, for the purpose of counteracting fluid turbulence. With this bell-mouthed arrangement the tendency for the oil to experience turbulence, and

consequently air occlusion, is reduced to a mini- Fluid under pressure is directed by the pump 92 into a vertical passage-way or channel H0 and thence through a horizontally disposed communicating passage-way II2, Fig. 3.v This passage-way H2 is blocked at itsouter extremity by a. suitable threaded plug II4. Fluid under pressure from the channel H2 is directed'downward- 1y through a longitudinal passage II6 provided within the piston rod 66 and thence through a radial opening II8 into the chamber I20 within the cylinder 52. At this point it will be understood that upward movement 01' the actuator cylinder 52 constitutes the working stroke with respect to the actuation of the um ro or 38. In.- t

p p p p 40 within the chamber no and the left side of the Fig. the actuator cylinder 52 is shown at its lowermost position in readiness to impart an upward stroke to the sucker rod 44, and in Fig.- 3 said cylinder is shown at the limit of its upward stroke.

Assuming that the constituent elements of the actuator 50, to-wit, the cylinder 52 and the piston 54, occupy the relative positions shown in Fig. 5.

it will be seen that fluid under pressure enters the restricted portion or the chamber I20 immediately above the fixed piston 54. This fiuid acting against the under side ot the pylinder cap 64 causes said cylinder, and consequently the sucker rod 44, to experience an upward movement. Just'prior to this upward movement, fluid under pressure from the chamber I20 communicates with a valve chamber I22 through a radial opening I24, a longitudinal opening or passage I26, a radial opening I28, and a channel I30 extending axially through a threaded cap or plug I32. This causes a transversely shii'table valve member designated generally by the numeral I34 to be shifted to the position shown in Fig. 5. Fluid from the advancing side of the valve member I34 passes through a channel or passage I38 extending through and axially of a threaded plug or cap I 38, a radial opening I40 in the cylinder 52, a longitudinal passage I42, a radial opening I40, and thence into an annular groove I46 provided within the piston 54. This annular groove I 46 communicates with a discharge opening or longitudinal passage I48 Within the piston rod 56 through a radial passage I50, a longitudinal passage I52, and an inclined passage I54, Fig. 6. The outer extremity of the inclined passage I54 is obstructed by a suitable plug I56 and the lower extremity of the longitudinal passage I52 is ob- .u the cylinder chamber I60.

structsd by suitable threaded plugs I58. with the valve in the position shown in Figs. ti and t, fluid item the chamber I60 below the piston 64 is free to pass from said chamber into the discharge 5 passage I40,*through a longitudinal passage I02,

I which is coextensive with the passage I48, and through crescent shaped ports I64 and I86 positioned on opposite sides or the valve member I34.

These crescent shaped ports I64 and I66, when the valve member I34 occupies the position shown in Figs. 5 and 6, main communication through groove I68 provided in the valve member it l. Thus. as the actuator cylinder 52 experiences its upward movement, fluid under pressure from the longitudinal passage II6 enters the cylinder chamber I and fluid from the cylinder cham ber I60 is discharged through ,the longitudinal passage I48. The upper extremity of the longitudinal passage I48 is blocked by a pin I10 and a 20 radial opening I12 connects said passage I48 with a chamber I14 which communicates with a discharge pipe or conduit I16 through a channel or passage I 18 provided in the base 58- (see Fig. 4). The outer extremity of the passage or channel I18 is blocked by suitable threaded plug I80. The

lower or discharge end of the pipe I18 is flared or bell-mouthed similarly to the lower extremity of the intake pipe I06 for the purpose of reducing as far as possible fluid turbulence.

As the actuator cylinder 52 reaches the uppermost limit of its movement, as shown in Figs. 2. 3, '7 and 8, fluid pressure acting upon the valve 'member I34 causes said valve to shift to the position shown in Fig. 3. The shifting of this 35 valve member I34 takes place as the passage I36 in the threaded plug I 38 is brought into registry with a port I82 provided in the inner wall 01 the cylinder 52. This por I82 serves to establish communication between the pressure fluid drill hole I30 which now communicates with a port I84, which at this instant also communicates with the annular groove I46 in the piston. As previously described, this groove I46 communicates with the discharge passage I48 through the 50 passages I50, I52 and I54. In this connection it is to e noted that the screw plug I58 may be adius ed so as to restrict communication between the passages I50 and I52 and thus control the speed of movement of the'valve member I34 when .5 such conditions are required.

It will also be noted that when the valve mem ber I34 occupies the position shown in Figs. 3 and 8, the annular groove I68 of the valve communicates with crescent valve ports I86 and I88.

These crescent ports communicate respectively with longitudinal passages I90 and I92. The upper extremities of these passages I90 and I02 communicate with the cylinder chamber I20. Thus, fluid pressure discharging from the 10ngic5 tudinal passage II6 into the cylinder chamber I20 also flows into the passages I90-I92, the

crescent ports I86-I88, the annular valve groove I68, and thence into a longitudinal passage I94 which communicates at its lower extremity with Thus, the fluid under pressure acting upon the greater cross-sectional area presented by the end plate or member 12 of the cylinder as compared with the oppositely disposed end suface of lesser cross-sectional area. causes the cylinder'52 to experience downward movement. During the downward movement or the actuator cylinder 32. fluid irom the chamber I20 is simply transferred to thechamber I80 through the passage-ways within the piston, as=

Just described. When the actuator cylinder 02 reaches its lowermost position, as shown in Fig. 5, the valve member I34 is automatically shifted to the left and a reversal of actuation takes place, as previously described. In other words, fluid under pressure delivered from the gear pump 82 to the actuator 50 serves to automatically reciprocate said actuator without the necessity of employing any external control elements such as dogs, trip elements and the like.

It will also be noted that the valve member I34 is positively locked against movement at all intermediate points oi! the cylinder stroke so that it cannot be joltedor shaken from the position it occupied at the beginning of the stroke. That is to say, the valve member I34 is locked against movement by fluid within the chamber in which the valve reciprocates. The fluid between the valve member I34 and the threaded plug I30 serves as ablock to prevent shifting of the valve member from the position shown in Fig. 3 and occupies the position shown in Fig. 5. In this connection it will also be noted that when the valve member I34 occupies the position shown in Fig. 5 the crescent ports I88 and I88,are blocked and when said valve occupies the position shown in Fig. 3 the crescent ports I64 and I86 are blocked. A series of piston rings I86 cooperates in preventing leakage oi fluid longitudinally of the piston suriaca, One of said piston rings traverses the screw plugs I82 and I38 in grooves extending transversely of said plugs and thereby secures them against rotation so as to maintain registration between the drill holes I30 and I36 and their companion ports or passages in the actuator cylinder. The looking of the valve member I34 in either of its positions may be subject to one difiiculty, namely, the tendency for slight leakage of fluid past a piston ring when the fluid pressure exceeds a certain maximum. This is particularly true with respect to the upper port of the piston in the vicinity of the screw plug I38 because only one piston ring is interposed between the upper end of the piston and the drill hole I36. On the other hand, two piston rings are interposed between the upper end of the piston and the drill hole I30 in the screw plug I32. Hence, leakage from the cylinder chamber I20 is counteracted by two piston rings at one side or the valve member I34 and by only one piston ring at the opposite side of said valve member. Leakage from the cylinder chamber I20 past the first piston ring I36 may have a tendency to cause the valve member to creep away from the screw plug I38. Any fluid thus displaced by the-,valve member would have a tendency to leak past the piston ring interposed between the valve member and the annular groove I46. To prevent this action from taking place a very small hole or bleed passage I98 is provided in the left section of the valve member I34 (see Figs. 3 and 6). This small hole I 98 serves to drain any slight leakage of fluid into the return channel I48 which, when the valve member occupies its left position shown in Fig. 5, communicates with the annular valve groove or port I68. When the valve member occupies the position shown in Fig. 3 adjacent the screw plug III, fluid may pass through this bleed passage from the annular valve groove Ill and in this event such fluid would tend to hold the valve member more flnnly in its position against the screw plug I32 because of the greater cross-sectional valve area against which the fluid acts. Hence, the presence of the vent I38 introduces no difliculty when the valve member I34 occupies the position shown in Fig. 3, and the only tendency for the valve member to creep would be in a directionaway iron: the.

screw plug I38.

In Figs. 9 to 18, inclusive, a modified hydraulic actuator designated generally by the numeral 50a is shown. Constituent elements of the actuator 50a which correspond with the elements of the actuator 50, such as the cylinder, end caps, 1 piston, piston rod. etcetera are designated by numerals corresponding to those. previously employed, together with the letter "a." In the actuator 60 just described the automatic reciprocation of the actuator cylinder takes place due to an arrangement of ports and passages provided in the cylinder wall and piston in such a manner as to preclude the necessity of employe ing any mechanically shiitable valve or pilot means for controlling the shifting of the valve.

member I34. In the actuator mechanism 68a shown in Figs. 9 to l8,'inclusive; a valve member I34a corresponding functionally with the valve member I34 previously described is employed. The shifting of the valve member I34a, however, is controlled by a pilot valve 200 which is longitudinally reciprocable within the piston 64a. As the actuator cylinder 02a reaches the limit or its downward movement, as illustrated in Fig.

10, the upper extremity of the pilot valve 200 is 'carried into engagement with the end member passage-ways and channels will be had. Withv the pilot valve 200 in the position ,shown in Fig.

10, fluid under pressure from the passage Illa, I

communicates through a passage 202 witha longitudinalpassage 204, the upper end of which communicates with the upper portion of the valve 200 and the lower extremity with the lower portionoi the pilot valve 200. With the pilot valve 200 in the positionshown, the lower extremity oi the longitudinal passage 204 commu- Y nicates with the annular groove or valve passage 206 which now registers with passages 208, 2I0 and 2I2. These passages are in communication with a passage 2, communicating with the valve chamber at the lower extremity of the valve member I34a. Thus, fluid pressure acting upon the valve member I340 causes said valve to be shifted to its uppermost position. Fluid from the chamber at the upper extremity of the valve member I 3411 communicates with a discharge passage I48a through passages 2I6, 2I8, 220, annular valve groove or port 222, radial opening 224, and annular groove or. passage 228 provided in the periphery of the piston 64a. This'annular groove 226, as shown in Fig. 14, communicates with the discharge passage I48a through an inclined passage 228. It will be apparent that when the valve member lfla occupies its uppermost position, fluid under pressure from the passage Ilia enters the annular groove 230, communicating with peripheral or segmental fluid passages '232 in the valve member i34a. These segmental valve passages 232 are now in communication with an annular passage 234 which in turn communicates with the cylinder chamber i2lla througha longitudinal passage 236, Fig. 14. This causes fluid pressure to act against the under side of the cylinder cap 64a, thus urging the actuator cylinder 52a upwardly. Fluidfrom the oppositely disposed chamber Hilla passes through a longitudinal passage 238 and into an annular valve .passage 240 which is now in communication with the annular piston passage or groove 226 through aradial passage 242.- As previously stated, this annular piston groove or passage 226 communicates with the return or .discharge passage 8a. 1

When theactuator cylinder 52a reaches the limit of its upward movement, the plate or cap 72a engages the depending lower extremity of the pilot valve 200, causing said valve to be shifted to the position shownin Fig. 9. When the valve is shifted to this position, fluid under pressure from the passage l I 6a. is directed by the pilot valve 200 through passages previously referred to into the chamber at the upper extremity of the valve member I34a so as to automatically cause said valve to be shifted to its lowermost position. In this position the segmental valve ports 232 serve to direct fluid under pressure from the longitudinal passage Ilia into the cylinder chamber ltna. through the annular valve passage 230, the annular passage 240 and the longitudinal passage 238. Fluid discharged from the cylinder chamber I200 during the downward movement of the cylinder 52:; is directed by the valve member l34a into the peripheral piston passage 22B and the return passage or duct Illa through channels or passages previously referred to.

For the purpose of more clearly understanding the locations of the various passages and ports Just referred to, I have disclosed the somewhat schematic sections in Figs. 15 to 18, inclusive, in addition to the rolled out" section shown in Fig. 14. Also the horizontal sectional views shown in Figs. 11 to 13, inclusive, considered in connection with the vertical sectional views shown in Figs. 9 and 10 clearly illustrate the structural and functional relationship of the cooperating ports and passages.

From the foregoing it will be apparent that the invention contemplates a hydraulic actuator arrangement which iscapable of receiving fluid under pressure from a given source, such as a mon practice to discharge water from a well into a suitable tank or container, not shown, and to maintain the air abovethe suriace of the water in the tank under pressure which is suflicient to force water from the tank when a faucet or valve connected with the tank is opened. The present invention contemplates the use of the air' pressure generating mechanism 82. This mechanism includes a cylinder 250 secured at its lower extremity to a base or support 252. Reciprocable within the cylinder zen and carried by the threaded portion 16 of the hydraulic actuator mechanism 50 are leather piston rings 254 and :56 carried by

suitable piston members

268 and 260, respectively. As these leather piston rings 254-d are urged downwardly within the cylinder 250, air is forced through a check valve 262 into the passage-way 2 and through the check valve 246. During the upward stroke of the leather piston rings 254-256 air is drawn through a tire inflation check valve 264 which communicates with the chamber within the cylinder 250 by suitable passage-ways 268 and 288. During this upstroke the check valve 282 prevents air from entering therethrough. It will be apparent, therefore, that the

hydraulic actuators

50 or 50a Just described cause the pump piston 42 to raise water and discharge same into the passage-way 244 during the upward stroke and cause air under pressure to be delivered into said passage-way during the downward stroke. Obviously, suitable controls, not shown, may be employed to start and stop the motor 84. For example, control mechanism for the motor may be governed by a float in the tank to which fluid is delivered or by the pressure of air therein, etcetera.

In order to facilitate access to the hydraulic actuator, the air pressure generating actuator and other parts within the housing 26, a suitable inspection guard or plate 210 is employed. Also, the inner wall of the oil reservoir is equipped with a detachable plate 212 held in place by suitable 1 screws 214, Fig. 2. When it is desired to drain fluid pressure generating means or pump, and

without the use of externally located control elements, causing the pump piston to experience continuous reciprocation as long as the electric motor 84 functions to propel the gears in the pump 92. Each upward movement of the pump piston 42 causes a charge of fluid, such as water, to be directed into the chamber 48 (Fig. 2) and thence through a passage 244 through a standard check valve designated generally by the numeral 246. This check valve permits fluid to be forced outwardly from the passage 2 and into a suitable pipe line 248 but prevents fluid from flowing back into-the passage 2.

Many pump installations require means for supplying air under pressure to the body fluid delivered by the pump. Thus, it has been comthe oil from the reservoir, a valve 216 in a pipe line 218 connected with the reservoir may be opened. Also, a suitable oil level indicator and flller 280, Fig. 1, may be used to facilitate fllling the reservoir and noting the level of oil therein.

From the foregoing it will be apparent that the present invention contemplates a well pump mechanism and hydraulic actuator arrangement of improved practical construction. It will also be apparent that the structural arrangement of the constituent elements is such as to make for simplicity in manufacture, emciency in operation and the utmost durability under the most severe operating'conditions. It will also be noted that the air pressure generating mechanism beneath the hydraulic actuator mechanism not only serves to provide air under pressure as described above, but also cooperates with the hydraulic actuator mechanism to provide a balanced cycle of operation. That is to say, the electric motor which supplies the power for generating fluid pressure within the actuator experiences no sudden change in operating speeds when the actuator stroke changes in direction. This is to be distinguished from conventional deep well pump water within the pipe and upon the other stroke is substantially free from any load. If an electric motor operated a well pump under such circumstances. it would have a tendency to speed up during the no-load stroke and to slow down during the pressure or working stroke. In the preaent arrangement as described here there are no' "power humps in the cycle of operation and hence the electric motor functions at maximum operating efficiency. Also the unique arrangement of the hydraulic actuator mechanism per se materially contributes toward the efficient and satisfactory functioning of the described mechanism. In this connection it will be observed that in instances where repair or replacement of the actuator mechanism becomes necessary the entire actuator including the cylinder and piston structure may be detached from the pump housing or frame and replaced by another. In this manner actuator mechanisms may be maintained in stock by a supply house, furnished for replacement on short notice, and installed with a minimum amount of effort and'skill.

Obviously, the invention is by no means limited to the specific embodiment disclosed herein but is capable of other applications and modifications without departing from the spirit and scope of the appended claims.

The invention is hereby claimed as follows:

1. A well pump mechanism including a vertical conduit adapted to extend downwardly from a well platform, reciprocable pumping means located at the lower extremity of said conduit, a

hollow housing adapted to extend upwardly from said platform, reciprocable hydraulic actuator mechanism in and mounted on said housing and including a cylinder and piston construction extending downwardly from said housing through said conduit to said pumping means for reciproeating said pumping means, fluid pressure generating means for delivering fluid under pressure to said hydraulic actuator mechanism, means including fluid pressure actuated valve mechanism housed within said actuator mechanism for controlling the automatic reciprocation of said cylinder and piston construction, means for mounting said fluid pressure generating means in' said housing, said housing being constructed to enclose said actuator mechanism and said fluid pressure generating means and provided with means for mounting the housing on said well platform as a self-contained unit.

2. A well pump mechanism including a conduit adapted to be positioned beneath the surface of the ground, pumping means positioned at the lower extremity of said conduit, hydraulic actuator mechanism for actuating said pumping means, fluid pressure generating means for delivering fluid under pressure to said hydraulic actuator mechanism, air pressure generating means driven by said hydraulic actuator mechanism for supplying air under pressure to the body of fluid delivered by the pumping means, and a unitary housing and supporting structure mounting said hydraulic actuator mechanism, said fluid pressure generating means and said air pressure generating means as a self-contained replaceable unit adjacent the upper end of said conduit.

3. A driving mechanism for a well pump having a drop pipe and a well sucker rod therein, said driving mechanism including a unitary frame structure adapted for positioning above the drop pipe of a well, a hydraulic actuator mechanism including a reciprocable cylinder and stationary piston construction carried by said frame and adapted for connection with the well sucker rod, fluid pressure generating means carried by said frame for delivering fluid under pressure to said hydraulic actuator mechanism. and hydraulically actuated means in said cylinder for automatically controlling the direction of movement of li-ld hydraulic actuator cylinder, said unitary frame being constructed to enclose said hydraulic actuator mechanism and said fluid pressure generating means and providing integral supporting means for mounting the driving mechanism as a self-contained unit above the well drop pipe.

4. An actuator unit for a well pump having a drop-pipe, and a sucker rod, said unit including a unitary frame structure adapted for positioning above the drop pipe of a well, a hydraulic actuator mechanism carried by said frame structure and adapted for connection with the well sucker rod, fluid pressure generating means carried by said frame structure for delivering fluid under pressure to said hydraulic actuator mechanism, means supported by said actuator mechanism for automatically controlling the direction of movement of said hydraulic actuator mechanism, and

an electric motor carried by said frame structure 7 for propelling said fluid pressure generating means, said unitary frame structure being constructed to form a housing for said hydraulic actuator mechanism and said fluid pressure generating means and a support for said electric motor and being formed with integral mounting means for mounting of the mechanism as a unit above the drop pipe of a well.

5. A self-contained well pump actuator including a well sucker rod, a unitary frame structure, a hydraulic actuator mechanism carried by said frame structure and connected with the well I well pump, said frame structure and said mechanisms and means carried thereby forming a selfcontained actuator for mounting as a unit above the drop pipe of a well.

6. A well pump actuator including a well sucker rod, a unitary frame structure, a hydraulic actuator mechanism carried by said frame structure and connected with the well sucker rod, fluid pressure generating means carried by said frame structure for delivering fluid under pressure to said hydraulic actuator mechanism, means carried by said hydraulic actuator mechanism for automatically controlling the direction of movement of said hydraulic actuator mechanism, a

fluid reservoir carried by said frame structure, conduit means for conducting fluid from said reservoir to said fluid pressure generating means, and conduit means for directing fluid from said fluid pressure generating means to said reservoir, said unitary frame structure comprising means forming an open top housing enclosing said hydraulic actuator mechanism and said reservoir. means mounting said motor on said housing to close the open'top of said housing, said conduit means and said fluid pressure generating means being supported on said last mentioned mounting means and depending within said housing, said housing having an opening in the bottom thereof through which the well sucker rod extends.

7. An actuator mechanism for a well pump having a well platform, a drop pipe depending from said platform and a sucker rod extending through said drop pipe, said mechanismv including a unitary housing structure, a hydraulic actuator mechanism including a cylinder and piston construction carried by said frame structure and adapted for connection with a well sucker rod, fluid pressure generating mechanism carried by said frame structure for delivering fluid under pressure to said hydraulic actuator mechanism, and means carried by one of said mechanisms for automatically controlling the direction of movement of said hydraulic actuator mechanism, said housing structure forming a casing enclosing said actuator mechanism and having an open top, an electric motor mounted on said housing and closing the open top thereof, means for mounting said fluid pressure generating mechanism within said housing, the means for mounting said fluid pressure generating mechanism having conduits connecting said fluid pressure-generating mechanism to said hydraulic actuator mechanism, means for securing the piston of said hydraulic actuator mechanism to said mounting actuator unit comprising an upstanding, enclosing housing adapted to be mounted on the well platform. said housing having an open top wall,

' a pump mounted on said housing enclosing said open top wa1l,-a fluid motor having a vertically extending piston mounted on the casing of the pump and projecting within the housing, said fluid motor including a cylinder slidably mounted on said piston and enclosing the same, fluid passages in the pump casing and in the piston connecting fluid forcing elements of the pump to the inner chamber of the cylinder, a pump driving motor supported by and surmounting said pump, a fluid reservoir within the housing and carried thereby, means forming with wall portions of the enclosing housing a fluid receiving chamber therewithin, means adapted to establish fluid communication between said fluid receiving chamber and the drop pipe of the well pump mechanism, an actuated rod connected to the cylinder of. the fluid motor and adapted to project from said housing through said fluid communicameans forthe fluid pressure generating mechanism and depending therefrom, said housing having an opening in the bottom thereof in alignment with saidpi'ston, a reciprocable cylinder enclosing said piston, said piston having conduits therein for conducting fluid to and from said cylinder, an actuator rod aligned with said cylinder and extending through the opening in the bottom of the housing for connection to a well pump, said housing being formed to provide integral mounting means whereby said actuator mechanism may be mounted and replaced as a unit.

8. A self-contained actuator unit including a unitary housing structure, a pump mounted in said housing structure and secured thereto, ;a hydraulic motor mounted in said housing structure and secured thereto, means forming with said housing a reservoir within the housing, means carried by and enclosed within said housing structure and providing fluid conduits connecting said reservoir to said pump, said pump to said motor, and said motor to said reservoir, a fluid controlled reversing valve carried by said motor for determining the direction of movement of said motor, and an electric motor carried by said housing structure and connected to said pump to drive said pump, and a connection from said fluid motor projecting from said housing structure for attachment to a member to be operated, said housing structure supporting and enclosing the aforementioned elements so as to present a self-contained actuator unit.

9. A self-contained hydraulic actuator unit comprising an enclosing housing having an open wall, a pump mounted on said housing and closing said wall, a fluid motor mounted on the casing of said pump within said housing, fluid passages in the casing of the pump connecting fluid forcing elements of the pump to the fluidmotor,

a reservoir having wall portions formed integrally with the housing and a separable wall portion attached to said integral wall portions to form a reservoir tank within the housing, conduits within the housing and connecting passages in the pump casing from the fluid motor and the fluid forcing elements of the pump to the reservoir and an actuator member connected to the fluid motor and projecting from the housing.

tion establishing means for connection to-the pump of the well pump mechanism, an exhaust 10. A self-contained hydraulic actuator unit for driving a well pump mechanism including a well platform, a drop pipe, and a well pump, said passage from said housing for the fluid received within said fluid receiving chamber from the drop pipe of the deep well pump mechanism, and valve means automatically controlling said exhaust passage;

' 11. A deep well pump mechanism including a vertical conduit adapted to extend downwardly from a well platform, pumping means positioned at the lower extremity of said conduit, a hollow housing adapted to extend upwardly from said platform, hydraulic actuator mechanism in and mounted on said housing and including an actuator extending downwardly from said housing through said conduit to said pumping means for actuating said pumping means, fluid pressure generating means for delivering fluid under pressure to said hydraulic actuator mechanism, an electric motor for driving said fluid pressure generating means, and means for mounting said motor and fluid pressure generating means in and on said housing.

12. An hydraulic actuator unit comprising reciprocable hydraulic actuator mechanism including a cylinder and piston construction, hydraulic pressure generating means for delivering an incompressible fluid under pressure to said hydraulic actuator mechanism, an hydraulically actuated reversing valve housed within said actuator cylinder for automatically controlling the direction of reciprocation of said actuator mechanism, and means including mating fluid directing passages in said cylinder and piston controlled by the relative movements of said cylinder and piston for supplying fluid from said pressure generating means to one side of said valve and returning it from the other side to said pressure generating means, and conversely, to effect movements of said valve in opposite directions at the opposite limits of the relative movements of said piston and cylinder.

13. In a well pump mechanism an hydraulic actuator mechanism including a cylinder and piston construction, hydraulic pressure generating means for delivering an incompressible fluidunder pressure to said hydraulic actuator mechanism, said hydraulic actuator mechanism having a piston rod apertured to conduct the fluid into inder chamber on one or the other side or the piston and the return of fluid from the one or the other side of the piston to the pressure generating means whereby to control the relative movements of the piston and cylinder in'opposite directions, selectively, said valve means including a shiftable valve member and means including spaced fluid directing passages in said cylinder and mating fluid directing passages in said piston for supplying fluid from the cylinder to one side of said valve member and returning it from the other side to said pressure generating means, and conversely, to elTect opposite movements of said valve member at opposite limits of the relative movement of said piston and cylinder.

1 4. An hydraulic actuator mechanism including reciprocable cylinder and piston means for coupling said actuator mechanism to a source of liquid under pressure, liquid directingpassages.

within said piston structure for directing liquid under pressure to the area within the cylinder on either side or the piston. hydraulically shiftable of said valve means to said source, and conor the other side of the'piston whereby to control the direction of movement of said hydraulic actuator. mechanism, said piston having passages therein for directing operating fluid into said valve means and returning it from said valve means to the source, and spaced passages in the wall of said cylinder for alternatively establishing communication between certain of said piston passagesv and said cylinder and between other of said piston passages and said source for supply ing fluid from said cylinder to one side of said valve means and returning it from the other side versely, to eflect reversing movements of said valve means at opposite limits of the relative movement 01' said piston and cylinder.

ERNEST J SVENSQN.