US2185680A - Well pumping mechanism - Google Patents

Description

1940- E. w. PATTERSON ,1 ,63

WELL PUMPING MECHANISM Filed June 1'7, 1936 Patented Jan. 2, 1940 WELL PIMPING MECHANISM Edgar W. Patterson, Los Angeles, Calif., assignor of one-half to Margaret D. Patterson, Long Beach, Calif., and one-half to Charles M. OLcary, Jr., Los Angeles, Calif.

Application June 17,

7 Claims.

The present invention relates generally to well pump operating mechanism and has to do in particular with the application of an air balancing apparatus, or pneumatic counterbalance,

6 to well pumpin units of standard manufacture and use, employing walking beams of the type pivoting at or near the centers thereof on Samsonposts and wherein power for pumping purposes is applied to the opposite end of the walktached to, and operates, the polish rod.

Pneumatic counterbalances or air balancing apparatus are well known at the present time and may be applied to standard walking beams of the above type or, as generally applied, to walking beams which extend to one side only of the Samson posts forming their pivotal support, the power being applied to the beam between the Samson post and the end thereof connected to the polish rod. Since, however, the air balance exerts itself in a direction assisting the power applied to lift the polish rod and resist the same as applied during lowering of the polish rod, applications of air balances up to' the present time to standard units have resulted in alternately placing the Samson post under tension andcompression, and this is a decided disadvantage which it is the primary object of the present invention to avoid.

For the above reasons, and in carrying out the present improvements, an air balance is so constructed and applied to the intermediately pivoted walking beam of a standard pumping unit that downward pressure will be created upon the 35 pivot during both upward and downward movements of the power end of the beam so 'as'to thus continuously maintain the Samson post under compression.

The above is preferably accomplished in a manner which will now be described in detail, with reference to the accompanying drawing, which forms a part of this specification, and in which,

Figure 1 is a side elevation of a pumping unit embodying the present invention, and

Figure. 2 is a detail vertical sectional view through the air cylinder and associated parts.

Referring now to Figure 1, the walking beam III, as shown, of a standard pumping unit, has a pivotal support I l intermediate its ends upon the upper end of a Samson post I21 Power is applied to one end of beam l through a connecting rod l3 and crank M, from a shaft I5, the

large pulley [6 of which is driven by a belt I1.

55 from any suitable source of power. The opposite ing beam with respect to that end which is at- 1936, Serial No. 85,774

end of the beam may have a cable segment I8, the cables I9 from which depend to a polish rod clamp 20 by which they are made fast with the upper end of the polish rod 2|. As usual the polish rod 2| passes downwardly through a stufi- I ing box 22 of the well casing 23 and, within the latter, is fixed to the sucker rods which extend, as well known, to the pump plunger deep in the well.

'All of the above are conventional parts of the standard pumping unit or rig and may therefore be widely varied in detail insofar as the present invention is concerned as long as a beam is employed with an intermediate pivot on a Samson post for the application of power to one end and the actuation of the polish rod from its other end, or in other words as long as a walking beam constituting a lever of the first class is present.

'As shown in Figure 1, a cable segment 24 is, according to the present invention, mounted on beam l0 between its pivot bearing I l and its end engaged by the connecting rod 13, and the cables 25 from this segment 24 are connected at their lower ends to a crosshead 26 to which the lower end of a piston rod 21 is fixed.

A piston 28 at the upper end of piston rod 21 works in the air cylinder 29 and this cylinder is securely mounted in upright position upon a pedestal 30 having vertical side slots 3| which form guides for the crosshead 26. The upper 80 end of cylinder 29 is closed except for the communicating end of an air supply pipe 32 which leads from a reservoir tank 33 and is provided with a cut-01f valve 34 and a branch pipe 35 between the cylinder and cut-ofi valve 34, which 85 branch pipe 35 opens into the atmosphere and is provided therein with a cut-01f valve 36.

As seen in Figure 2, piston rod 21 may enter the lower end of cylinder 29 through a lubricant holding cup 31 which forms an oil trough 38 around the lower inner portion of the cylinder, and which opens upwardly so that at the end of each downward stroke of the piston 28 the lower edge of its skirt dips into the oil in the oil trough 38 whereby to maintain efiicient lubrication of the piston at all times. However, other means of lubrication may be resorted to with the same object in mind.

The reservoir tank 33 is in practice maintained with an internal air pressure which is substantially uniform during operation, and this may be accomplished in any suitable manner, air pressure being supplied by a suitable air compressor 39 actuated by a motor 40 and connected to tank bearing l I with a downward pressure on the Samson post l2. The power thus absorbed by the compression of air in cylinder 29 expends itself in the next downward stroke of the power end 1 of beam l0, during which it assists the applied power to the extent of equalizing the weight o1 the rods plus one-half the weight of the fluid being lifted in the pumping operation. Obviously, during this latter stroke the pressure of bearing l l is downwardly on the Samson post i2 and thus the latter is uniformly subjected to compression throughout the entire pumping operation in a manner which aids greatly in prolonging the effective life of the unit.

It is plain the cylinder 29 may be vented to the atmosphere by opening valve 36 at any time it is desired to lower the polish rod 2I,. after closing valve 34, and that the rod end of beam I0 may be raised by closing valve 36 and then opening valve 34 where this movement would be difficult to control from the power connections.

It is thus plain the invention contemplates a novel, advantageous arrangement of coacting parts in a well pumping mechanism, wherein the power operation is effectively balanced and wherein the opposite stresses and strains to which the Samson post is ordinarily subjected are elimian air balancing apparatus including means for creating and maintaining a constant air pressure in connection with the beam. to counterbalance its movements and at the same time exerting continuous downward pressure of the beam pivot on the Samson post throughout both upward and downward movements of the power end of, the beam. I

2. In a well pumping mechanism, the combination of a Samson post, a walking beam pivoted intermediate its ends on said post, power means for raising and lowering one end of said beam, connections extending from the other end of the beam for actuating the sucker rods of a well, and

an air balance including an air cylinder and piston and means for creating and maintaining a constant air pressure in said cylinder in connection with the beam. at a point between its pivot and the power end of the beam and serving to create downward pressure of the pivot on-the Samson post continuously throughout both upward and downward movements of said power end of the beam.

3. In a well pumping mechanism, the combination of a Samson post, a walking beam pivoted intermediate its ends on said post. power means for raising and lowering one end of said beam, connections extending, from the other end of the beam for actuating the sucker rods of a well, a

stationarily supported air cylinder, a piston therein having a rod depending below the cylinder, a connection between the said piston rod and the beam at a point between the beam pivot and its power end, and means for maintaining a constant air pressure in communication with the cylinder at a point above its piston.

4. In a well pumping mechanism, the combination of a Samson post, a walking beam pivoted intermediate itsends on said post, power means for raising and lowering one end of said beam, connections extending from the other end of the beam for actuating the sucker rods of a well, an air cylinder, a piston therein, a rod depending from the piston below the cylinder, at crossheadcarried by the piston rod, a stationary support for the cylinder having guides for said crosshead, a cable segment connected to the beam at a point between its pivot and the power end thereof, cables depending from said segment and connected to said crosshead, a pressure reservoir connected to the cylinder above the piston therein and means for maintaining a constant pressure in said reservoir.

5. In a well pumping mechanism, the combination of a Samson post, a walking beam pivoted intermediate its ends on said post, power means for raising and lowering one end of said beam, connections extending from the other end of the beam. for actuating the sucker rods of a well, an air cylinder, a piston therein, a rod depending from the piston below the cylinder, a crosshead carried by the piston rod, a stationary support for the cylinder having guides for said crosshead, a cable segment connected to the beam at a point between its pivot and the power end thereof, cables depending from said segment and connected to said crosshead, and pressure supply means including a reservoir connected to the cylinder above the piston therein and means for maintaining a constant pressure in said reservoir, said pressure supply means also including a supply pipe having a cut-off valve therein and having a valve controlled vent between said cut-01f valve and the cylinder. v

6. In combination with a well pumping apparatus including a walking beam having pump connections at one end and power connections at its opposite end, anda Samson post on which the beam is intermediately pivoted, an air bal* ance including means for creating and maintaining a constant air pressure in connection with said beam to equalize its efiective movements and maintaining the Samson post pivot under uniform compression continuously during pumping operation.

7. In a well pumpingmechanism, the combination of a Samson post, a walking beam pivoted intermediate its ends on said post, power means for raising and lowering one end of said" beam, connections extending from the other end of the beam for actuating the sucker rods ofa well, an air cylinder having a closed upper end, a piston therein, a rod depending from; the piston below the cylinder, a guide forfthe piston rod .below the cylinder, flexible connections attached at their lower ends tothe piston rod and at their I upper ends to the walking beam at a point between its pivot and the power end thereof, pres- I sure supply means leading to the cylinder above

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