US2976812A - Heavy oil feed pump - Google Patents

Description

March 28, 1961 F. w. PLEUGER Erm. 2,976,812

HEAVY OIL FEED PUMP 2 Sheets-Sheet 1 Filed Sept. 9, 1958 March 28, 1961 F. w. PLEUGER ErAL 2,976,812

HEAVY OIL FEED PUMP 2 Sheets-Sheet 2 l LII Filed Sept. 9, 1958 nitd SQCS Patent e HEAVY OIL FEED PUMP Friedrich Wilhelm Pleuger, Juthornstrasse 80, and Heinz Ghring, Hamburg-Wandsbek, Germany; said Ghring assignor to said Pleuger Filed Sept. 9, 1958, Ser. No. 759,927

Claims priority, application Germany Sept. 10, 1957 13 Claims. (Cl. 10S-179) The invention relates to a heavy oil feed pump with a hollow piston slidingly mounted on the outer surface of a hollow cylinder, which piston includes a knife-edgeshaped end provided with a ap valve which is linked to a piston rod centrally guided in the hollow cylinder so that the piston rod can be moved by a limited amount with respect to the hollow piston and so that the ilap valve |alternately closes and opens on any reversal of piston movement.

The present invention has the purpose of improving heavy oil pumps of the kind mentioned and of so constructing them that an improved connection is achieved between the ap valve and the hollow piston, whereby wear is reduced and the durability of heavy oil pumps increased. Furthermore, by the invention, a lesser loading of the actuating member provided between the piston rod and the flap valve is achieved.

To solve the problems mentioned, in accordance with the invention, it is proposed to connect the flap valve with a lost motion connection to its actuating rod operated by the piston rod and to mount it eccentrically with respect to the hollow piston axis, so that, after a partial closing by the actuating rod, it is urged into the fully closed position by the hydrostatic pressure of the oil contained in the hollow piston. A bolt and longitudinal slot connection between the piston rod and an -intermediate lever pivotally connected with a pivot arm on the flap valve preferably provides for the necessary lost motion between the ap valve and the piston rod.

According to a further feature of the invention, the flap valve, whose pivot is preferably arranged outside the sealing plane of the valve, is constructed as a circular valve plate, which co-operates with a valve seating ring inserted in the hollow piston and includes a ring provided with sealing surfaces, which ring is axially shiftably mounted in sealing fashion on an inner guide part of the ap valve. To support the flap valve in the closed position, a counter-bearing is preferably arranged in the hollow piston beneath the flap valve.

Further details and features ofthe invention will appear from the following description and the accompanying drawings in which an embodiment of the invention is illustrated.

In the drawings:

Fig. 1 shows the whole of the heavy oil pump accord- -ing to the invention during the upward and supply stroke;

Fig. 2 shows the lower part of the pump illustrated in Fig. l on an enlarged scale; Y

Fig. 3 shows the lower part of the heavy oil pump according to the invention during its downward stroke;

Fig. 4 shows a broken-away sectional illustration of a further embodiment of the heavy oil supply pump accord- `ing to the invention, which can be releasably inserted in a rising pipe as an inserted pump.

In the various figures, the same or corresponding parts are provided with the same references.

The pump housing constructed essentially as a hollow 2,976,812 Patented Mar. 28, 196.1

cylinder 1 is screwed into a connecting member 2, by means of which it can be screwed into a rising pipe in the usual way. The threading between the rising pipe and the connecting member 2 consists of a helical thread 4. The screw connection 5 between the hollow cylinder 1 and the connecting member 2 is sealed by means of a sealing ring 6.

A hollow piston 7 is slidingly mounted on the hollow cylinder 1. The hollow piston 7 carries on its upper end, as a seal, a stop bushing S which can be drawn up by menas of a screw-threaded ring 9. In order to minimize friction between the hollow cylinder 1 and the hollow piston 7, a sand protecting ring 51 is inserted at the lower end of the hollow cylinder 1. At the lower end of the hollow piston 7, across head 10 is arranged which has a guide bushing 11 in its middle part, in which the lower end of a piston rod 12 is guided. The piston rod 12 extends axially through the hollow cylinder 1 land is provided at its upper end with a connecting member 13 by which it can be connected to a pump actuating rod of normal construction. A further guide for the piston rod 12 is the abutment member 14, which is rigidly inserted in the hollow cylinder 1 and is surrounded by a bearing bushing 15.

In the hollow piston 7 in the vicinity of its forward knife-edge-like end, a flap valve 16 made of several parts is provided, including an inner guide member 41 and a valve ring 42. The valve ring 42 is mounted in its axial direction so as to be limited as regards movement relative to the inner guide part 41 and is sealed by a sealing ring 43. On the forward side of the inner guide part 41, a counter-bearing plate 44 is secured by screws 45. This plate has a projecting peripheral part 46 for limiting the axial movement of the valve ring 42. An elastic ring 4'7 inserted between the valve ring 42 and the peripheral part of the counter-bearing plate 44 cushions the relative movements between the valve ring 42 and the inner guide part 41. The flap valve 16 is pivotally mounted about a bolt 17 inserted in the hollow piston 7. The sealing between the flap valve 16 and the hollow piston 7 is eiected by co-operation between the valve ring 42 and a seating ring 48 inserted in the hollow piston 7, which, in the same way as the corresponding ycounter surface of the valve ring 42, is chamfered in conical shape. l

A pivot arm 18 is provided for moving the valve mem ber 16 and is linked by means of a bolt 20 to a rigid intermediate lever 22, which in turn is connected pivotally with the piston rod head 27. The piston rod head Z7 is screwed to the free end of the piston rod 12 by means of a screw thread 28 and is secured by means of a bolt 29.

An elongated slot 49 is located in the piston rod head 27 in which the connection bolt 30 of the intermediate lever 22 is guided.

For inserting the flap valve and the actuating rod, the hollow piston 7 is made in several parts and consists, apart from its main section, of two short end sections 7' and 7, which are connected together by means of screw thread connections. Between the hollow piston sections 7 and 7", the valve seating ring 48 is inserted. Further, in the lowermost hollow piston section 7", a counter-bearing bolt 50 is located, on which the middle part of the flap valve 16 can be supported in the closed position illustrated in Fig. l.

An annular valve seat 3l is inserted above the cross head 10 in the hollow cylinder 1. This valve seat 31 co-operates with a conically-shaped valve body 32 which is mounted with a central bore on the piston rod 12. In order to achieve a satisfactory sealing with the valve body 32 with respect to the piston rod 12, a stop bushing is arranged inside the valve body 32, which consists of the sealing lips 33 and the screw-threaded nipple 34.

By means of the upper abutment member 14, which co-operates with the projection 40 on the piston rod, the downward movement of the heavy oil pump is limited. The limitation of the upward movement of the heavy oil pump is effected with the aid of the piston rod head 27, which abuts the guide bushing 11 of the cross head 10.

The heavy oil pump according to the invention operates as follows:

The pump is installed in the oil supply line in the vertical position and the connecting member 2 is screwed with its helical thread on to the lower` end of a rising pipe. The connecting member 13 of the piston rod is connected with a powered upwardly and downwardly movable actuating rod. It will be understood that the pump does not need to operate with the maximum stroke determined by the upper and lower stroke limits, but that the piston rod can be moved to-and-fro by its drive over a smaller stroke.

In the downward movement of the piston rod 12, the pump parts assume the positions illustrated in Fig. 3. The piston rod head 27 is lowered from the cross head 10 and has swung the flap valve 16 via the intermediate lever 22 so that it is in the position shown in Fig. 3. In this position, the link bolt 30 between the intermediate lever 22 and the piston rod head 27 lies at the upper edge of the elongated slot 49. By the transmission of force from the piston rod 12 via the intermediate lever 22 and the valve ap bolt 17 and also by its weight, the hollow piston 7 is moved downwardly until its sharpened front surface 3S is forced into the viscous heavy oil to be supplied.

As soon as the piston rod has reached its lowest point, its movement reverses and it begins to move upwardly again. The initial movement of the piston rod is elected rstly without carrying up the hollow piston 7, since the piston rod head 27 is not against the cross head 10.

In this initial movement of the piston rod, the flap valve 16 moves from the open position illustrated in Fig. 3 in the direction towards the closed position illustrated in Figs. l and 2. By reason of the long slot and bolt connection 30, 49 provided between the piston rod head 27 and the intermediate lever 22 and the specially selected dimensions, the iiap valve 16 cannot be completely closed by the relative movement between the piston rod and the hollow piston 7, but a slight clearance is initially maintained between the valve ring 42 and the seating ring 48. Since the pivot axis 17 for the flap valve 16 is arranged eccentrically with respect to the hollow piston 7, the amount of heavy oil closed off above the iiap valve operates by its hydrostatic pressure so that it eiects complete closure of the flap valve. In this second completed closure movement of the valve, the valve ring 42 moves in the axial direction with respect to the inner guide member 41 until there is tight engagement of the sealing surfaces of the two rings 42 and 48. In this completely closed position, the middle `part of the ap valve member 16 rests upon the counter bearing bolt t). Y

By the two part closure movement achieved in accordance with the invention, of which the lirst is effected exclusively by the piston rod and the second exclusively by the hydrostatic pressure, there is given, without using corrosion-sensitive spring elements, a very easy operation of the valve and sharp mechanical strokes on the seating surfaces of the valve are safely excluded in operation. The resulting extension of the life of the Ypump is obvious. It may be mentioned that, between the inner guide part 41, 44 and the valve ring 42 of the flap valve 16, a ring 47 consisting of elastic material can be provided, which provides a cushioning additional to that already achieved due to the viscosity of the oil.

After the flap valve 16 has closed and the piston rod head 27 has contacted the cross head 10, the whole hollow piston together with the amount of heavy oil enclosed above the valve plate 16 moves upwardly with respect to the stationary hollow cylinder 1. In this supply movement, the heavy oil at the cross head 10 is forced through the central valve seat 31. The valve cone 32 is raised against thepressure of the oil column but prevents return of the oil on reversal of the movement of the piston rod. Above the valve cone 32, the heavy oil can be raised further by the projection 14 illustrated in section, in order to be advanced with the piston rod 13 and the enclosed pump rod via the rising pipe (not shown) but which is coupled to the member 2 as described.

The embodiment of Fig. 4 is an insert pump which, in contrast to the usual deep well pumps, is not insertable and removable by means of the rising pipe, but exclusively by the pump rod and hence involves a considerfable saving in time and cost. Whereas in the embodiment of Figs. l to 3 the pump housing 1 constructed as a hollow cylinder is screwed into the rising pipe by an intermediate member 2, in the embodiment according to Fig. 4, a rapidly releasable connection between the rising pipe and the pump housing 1 is provided.

For connecting the pump housing 1 and the rising pipe 52, a hardened steel ring 53, a spread connecting sleeve 54 provided at several positions on its periphery with longitudinal slots and a hardened steel ring 55 are provided. The steel ring 55 and the expanded connecting sleeve S4 are secured to a housing part 56 which, instead of the abutment member 14 ofthe construction according to Figs. l to 3, undertakes guiding of the piston rod 12 and is connected with the hollow cylinder 1 by means of a connecting sleeve 57. As can be seen from Fig. 4, the housing part 56 consists of two cylindrical sections which are received between the ring 53 and the sleeve 54. The steel ring 5S is secured in the region of a connesting sleeve 58 by screwing between two sections of the rising pipe 52. The outer diameter of the ring 53 is greater than the inner diameter of the ring S5 and smaller than the inner diameter of the rising pipe 52, so that on inserting the pump 1n the rising pipe the ring 53 can rest on the ring 5S in order to limit downward movement of the hollow cylinder 1. The slotted connecting sleeve 54 is so dimensioned that its minimum outer diameter is smaller than the inner diameter of the ring 55, whereas its maximum outer diameter, that is its outer diameter in its expanded state, is greater than the inner diameter of the ring 55 and somewhat smaller than the inner diameter of rising pipe 52. In this way, the connecting sleeve forms Yan abutment which limits upward movement of the hollow cylinder 1.

The insertion of the pump in the rising pipe 52 is effected by inserting the pump from above into the rising pipe until the initially stressed parts of the connecting sleeve v54 are spread or expanded outwardly behind the ring 55 and the ring 53 comes to rest upon the upper edge of the ring 55.

In order to ensure a tight seating of the pump in the rising pipe, the opposite inclined surfaces between the 'rings 53 and 55 and between the sleeve 54 and ring 55 are made inclined. The inclination between the front surface of the sleeve S4 and the ring 55 preferably amounts to about 30, so that on applying a tensile force to the housing part 56 which exceeds the normal actuating force of the pump, the snap connection between the elements 53, 54 and 55 can again be released.

The operation of the pumping process is the same as 'in the pump embodiment described previously in connection with Figs. l to 3. As shown in Pig. 4, a screwable rod coupling 59 is provided as the connection between the piston rod 12 and the pump actuating rod. In order to release this screwable rod coupling 59, projections 60 of a dog coupling are provided on the downwardly-directed front face of the coupling 59, which can co-operate with upwardly-directed projections 61 on the housing part 56. If the pump rod and hence the piston rod are moved downwardly, the projections 60 and 61 of the dog cou-` phng are engaged together, so that then the pump rod can be rotated relatively to the piston rod 12 to release the coupling.. The projections 60 and 61 form further one lower llimiting abutment for the pump rod and at the same time determine the lowest point of the hollow piston 7, 1n order to prevent the latter from shifting too far with respect to the hollow cylinder 1.

What we claim is: i

1. In pumping apparatus for an oil well the combination of a riser, a piston rod, a hollow cylinder secured to the riser, a hollow piston slidably mounted on the outer surface of the cylinder, a cross head for the piston rod secured to the inner wall of the hollow piston, said piston rod being mounted `to project through and slide with respect to the cross head, an enlargement secured to the piston rod below the cross head, which enlargement is adapted to be moved away from the cross head on the downward stroke of the piston rod and to be returned to engage the cross head on the upward stroke of the piston rod, whereby the hollow piston is supported by the piston rod, a ap valve pivoted in said hollow piston below said cross head upon a transverse axis at one side of the longitudinal axis of the hollow piston, operating linkage means between the piston rod and the flap valve, said linkage means including a lost motion coupling and said ap valve having an axially movable valve ring, and a seating ring carried by the inner wall of the hollow piston in position to cooperate with said valve ring, the flap valve being adapted to be moved by the linkage means to elect partial closing of the hollow piston and said valve ring being adapted to be moved by the hydrostatic pressure of the oil contained in the hollow piston to seat upon said cooperating seating ring and thereby complete the closure of the hollow piston during upward movement thereof.

2. In pumping apparatus for an oil well the combination of a riser, a piston rod, a hollow cylinder, a snap connection securing the hollow cylinder to the riser, the holding force of which snap connection exceeds the piston rod forces, a hollow piston slidably mounted on the outer surface of the hollow cylinder, a cross head for the piston rod secured to the inner wall of the hollow piston, said piston rod being mounted to project through and slide with respect to the cross head, an enlargement secured to the piston rod below the cross head, which enlargement is adapted to be moved away from the cross head on the downward stroke of the piston rod and to be returned to engage the cross head on the upward stroke of the piston rod, whereby the hollow piston is supported by the piston rod, a ap valve pivoted in said hollow piston below said cross head upon a transverse axis at one side of the longitudinal axis of the hollow piston, operating linkage means between the piston rod and the flap valve, said linkage means including a lost motion coupling and said ap valve having an axially movable valve ring, and a seating ring carried by the inner wall of the piston in position to cooperate with said valve ring, the ap valve being adapted to be moved by the linkage means to effect partial closing of the hollow piston and said valve ring being adapted to be moved by the hydrostatic pressure of the oil contained in the hollow piston to seat upon said seating ring and thereby complete the closure of the hollow piston during upward movement thereof.

3. Pumping apparatus according to claim 2 wherein the snap connection includes a tirst ring rigidly secured in said riser, a second ring disposed on said hollow cylinder and an expansible sleeve spaced from said second ring and also disposed on said hollow cylinder, said first ring being arranged to occupy the space between said second ring and said expansible sleeve and being adapted to cooperate therewith.

4. In pumping apparatus for an oil well the combination of a riser, a piston rod, a hollow cylinder, a snap connection securing the hollow cylinder to the riser, the holding force of which snap connection exceeds the piston rod forces, a hollow piston slidably mountedY on the outer surface of the hollow cylinder, a cross head for, the piston rod secured to the inner wall of the hollow piston, said piston rod being mounted to project through and slide with respect to the cross head, an enlargement secured to the piston rod below the cross head, which enlargement is adapted to be moved away from the cross head on the downward stroke of the piston rod and to be returned to engage the cross head on the upward stroke of the piston rod, whereby the hollow piston is supported by the piston rod, a circular valve plate in said hollow piston below said cross head, said valve plate being pivoted in said hollow piston upon a transverse axis at one side ofthe longitudinal axis of the hollow piston, operating linkage means between the piston rod and the circular valve plate, said linkage means including a lost motion coupling, a seating ring carried by the inner wall of the hollow piston, said valve plate including an inner guide surface, a valve ring which is axially slidable on said inner guide surface, said valve ring having sealing surfaces adapted to cooperate with the seating ring on the wall of the hollow piston, said circular valve plate with its sliding valve ring being adapted to be moved by the linkage means to effect partial closing of the hollow piston and said sliding valve ring being adapted to be moved by the hydrostatic pressure of the oil contained in the hollow piston to seat upon said cooperating seating ring and thereby complete the closure of the hollow piston during upward movement thereof.

5. Pumping apparatus according to claim 4 wherein the snap connection includes a tirst ring rigidly secured in said riser, a second ring disposed on said hollow cylinder and an expansible sleeve spaced from said second ring and also disposed on said hollow cylinder, said first ring being arranged to occupy the space between said second ring and said expansible sleeve and being adapted to cooperate therewith.

6. Pumping apparatus according to claim 1 wherein the linkage means includes a pivot arm on the flap valve and a lever coupling said arm with the piston rod, and wherein the lost motion is provided for by a slot and bolt connection at one end of the lever.

7. Pumping apparatus according to claim 1 wherein the ap valve pivot is arranged outside the sealing plane of the valve.

8. Pumping apparatus according to cl-aim l wherein the valve seating ring is disposed in the hollow piston in a plane which is perpendicular to the longitudinal axis of the piston and wherein the ap valve is formed as a circular valve plate.

9. Pumping appartus `according to claim 8 wherein the seating ring and the valve ring are provided with conically inclined cooperating seating surfaces.

10. In pumping apparatus for an oil well the combination of a riser, a piston rod, a hollow cylinder secured to the riser, a hollow piston slidably mounted on the outer surface of the cylinder, a cross head for the piston rod secured to the inner wall of the hollow piston, said piston rod being mounted to project through and slide with respect to the cross head, an enlargement secured to the piston rod below the cross head, which enlargement is adapted to be moved away from the cross head on the downward stroke of the piston rod and to be returned to engage the cross head on the upward stroke of the piston rod, whereby the hollow piston is supported by the piston rod, a circular valve plate pivoted in said hollow piston below said cross head upon a transverse axis at one side of the longitudinal axis of the hollow piston, a valve seating ring disposed in the hollow piston in a plane which is perpedicular to the longitudinal axis of the piston, operating linkage means between the piston rod andthe valve plate, said linkage means including a lost motion coupling and said valve plate including an inner guide member and a sealing ring mounted for axial, sliding movement on the guide member, and means 'limit- 7 ing said movement, whereby, after a partial closing by said linkage means, the valve ring is forced into a fully closed position by the hydrostatic pressure of the oil contained in the hollow piston. i

11. Pumping apparatus according to claim 10 wherein a. counter-hearing is arranged in the hollow piston beneath the valve plate on which the said plate will be supported when the plate is in closed position.

12. Pumping apparatus according to claim 10 wherein an elastic ring is interposed between the guide member and the means for limiting said sliding movement whereby to cushion the sliding movement of the valve ring.

13. Pumping apparatus according to claim 1 wherein said hollow cylinder carries a sand protecting ring at S its lower end adapted to seal the sliding surfaces betwce said hollow cylinder and said hollow piston. Y I Y References Cited in the file of this patent vUNITED STATES PATENTS 90,157 Y Devirs et a1. Mag/18, 1869 282,973 Everitt Aug. 14, 1883 436,548 Smith Sept. 16, 1890 602,869V ONeil T Apr. 26, 1898 '11,871,577 Babin Aug. 16, 1932 2,519,142 Lehr Allg. 15, 1950 V2,825,288 Pleuger Mar. 4, 1958 e v FOREIGN PATENTS 23,271 Great Britain of 1894

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