US1951613A - Motorized counterbalance - Google Patents

Description

March 20, 1934. w JONES 1,951,613

MOTORIZED COUNTERBALANCE Filed May 23, 1932 5 Sheets-Sheet l INVENTOR. 14 600? M (70/765.

March 20, 1934.

IQTORI ZED QOUNTERBALANCE Filed May 23, 1932 3 Sheets-Sheet 2 A INVENTOR.

ATTORNEY w. M; JONES 1,951,613

March 20, 1934. w. M. JONES 1,951,613

MOTORIZED COUNTERBALANCE Filed lay 23, 1.932 3.Sheets-Sheet 3 Patented Mar. 20, 1934 PATENT OFFICE "UNITE-D; STATES MOTORIZED COUNTERBALANCE Wendell M. Jones, Los Angeles, Calif., assignor to Rotating Pumper Company, Los Angeles, Calif., a copartnership comprising William G. Corey,

-Wendell M. Jones, and L. O. Harbert Application May 23, 1932, Serial No. 613,116

Claims.

' In the operation of many' types of machines,

rotary driving means are provided, and due to the fact that there are load variances at periods in the cycle of rotation of the driving means, it is necessary t'oco'unterbalance the mechanism n so that there will be, as'nearly' as possible, a uniform stress upon the driving mechanism or power unit, irrespective .of the load variations of the driven unit.- This is especially true of such devices as reciprocating oil well pumps which are actuated by a long and heavy string of sucker rods or cable. If the string of rods or cable and part of the fluid -weight which is on the pump plunger were not counterbalanced, it would be necessary for the driving mechanism to lift this entire load of the-rods plus fluid onthe up stroke of the pump plunger, while on the down stroke the heavy weight of the rods would exert driving force on the driving mechanism. By

properly counterbalancing, the driving mechamore efficient operation; In view of the fact that reciprocating oil well pumps are operated at great depths with heavy strings of rods or cable, and upon their up stroke carry the weight of a relatively long and heavy" column of liquid, it is nec- 3 essary to supply counterweight means of large proportions and weight in order to maintain the driving unit in a smooth running operation. This requirements has produced a serious problem in oil well pump driving'and"counterbalance mechanism :4 desig'n'due to the-fact that-"the counterweight requires a special mountingof some form and often occupies considerable'space. This is aside from'thefa'ct that the counterweight itself is of such proportions as to make it an expensive item of construction and a difiicultobject to handle during operations other than pumping. It is the principal object of the present invention, therefore, to provide a well pumping organization with a continuous rotating drive unit and a reciprocating pump 'unit, and to eliminate expensive weight means by utilizing the motor driving unit as the counterweight for the organization.

The present invention contemplates the provisicn of a reciprocating pump unit connected by its actuating rods to one end of a walking beam. The opposite end of said beam being connected by a simple form of pitman rod to a driving crank shaft upon which a sprocket is freely mounted and held against rotation, or caused to rotate 1 at a governable rate of speed and direction, and upon which crank shaft a counterweight arm is keyed to rotate with the shaft while extending radially therefrom, said arm carrying a motor drive unit and a sprocket, the sprocket being fitted with a sprocket chain passing around it and the fixed driven sprocket by which arrangement the entire motor unit upon its radial counterweight arm will gyrate around and with the crank shaft to drive the same.

The invention is illustrated by way of exam-:

ple in the accompanying drawings, in which:

Figure l is a view in elevation showing a form of my invention in which the main body of the drive is mounted between jack posts.

Fig. 2 is a view in end elevation showing the structure as seen on the line 2-2 of Fig. 1.

Fig. 3 is a view in side elevation showing another form of the invention in which the drive mechanism is mounted at the outside of one of the jack posts.

Fig. 4 is a view in end elevation showing a variation in the drive of the structure as shown along line 4-4 of Fig. 3.

Fig. 5 is a small diagrammatical view showing the application of the present invention to an oil well pumping rig.

Fig. 6 is a diagrammatical view in side elevation showing a variation of the present givention.

Fig. '7 is a graph indicating typical power curve obtained by the present invention, and other types of drives.

Referring more particularly to Fig. 6 of the drawings, 10 indicates a derrick floor above which is erected an oil well derrick 11. This derrick is disposed over an oil well 12 into which a pump rod 13 extends. The lower end of the pump rod is suitably connected with a pump plunger mechanism 14 of any preferred design, it being understood that the pump operates by reciprocation. The upper end of the pump rod 13 connects to the one end of a walking beam 15 which beam is pivotally mounted upon a Samson post 16. The opposite end of the walking beam 15 is pivotally connected to a pitman rod 17, the lower end of which is secured to a crank 18 mounted upon the usual band wheel shaft 19. The shaft 19 is rotatably supported in a horizontal position in bearings carried at the upper ends of jack posts 20. The rod and fluid load is usually counterbalanced by some preferred means, such as a counterweight disposed radially of the shaft and eccentric thereto, or counter- Weights associated with the pitman rod 17 or the walking beam 15. In the present instance, however, the motor driving unit provides its own counterweight. This unit comprises an electric motor 21 secured to a reduction gear unit 22. It is to be understood that other types of motive power might be utilized if found practicable, and that various designs of reduction gears might be used. In the present instance, however, the reduction gear unit is enclosed within a housing 23 and includes a driven shaft 24 connected with the rotor shaft of the motor 21. This driven shaft is provided with a gear pinion 26 in mesh with gears 27 and 28 disposed upon opposite sides of the pinion 26 and carried upon parallel shafts 29 and 30. The lower ends of these shafts carry gear pinions 31 and 32, respectively, which are in constant mesh with a gear 33 mounted upon a driven shaft 34. The driven shaft 34 carries a sprocket 35 around which a sprocket drive chain 36 is led. The sprocket drive chain 36 also passes around a main sprocket 37. This last named sprocket may be formed in any manner, as for example, mounted to become a part of the bearing carried upon one of the jack posts 20, or being separate if so desired. In any event, the sprocket is disposed concentrically of the axis of the band wheel shaft 19 and is either fixed with relation th reto, or driven by a sep arate power mechanism of a predetermined speed, and direction, which speed and direction determine the rate of rotation of the main unit and crank shaft. The motor 21 and its gear unit 22 are carried upon a radial counterweight arm 38. This radial arm is formed with a hub 39 through which the band wheel shaft 19 ex-- tends, and within which it is keyed. In this manner the counterweight arm will gyrate around the axis of the band wheel shaft as the band wheel shaft rotates. The outer end of the counterweight arm is formed with a base plate 40 upon which the base member 41 of the gear unit 22 may be bolted as indicated at 42. It will, therefore, be evident that the counterweight arm with adjustable weights and the motor and gear unit mounted at the outer end thereof will provide a lever arm which may act as a suitable counterweight when of the proper weight and when placed in proper counterbalancing relation to the actuating crank of the pump unit 14 at the opposite end of the walking beam 15.

In order that the motor and gear unit may act through the driving sprocket 35 to drive the band wheel shaft 19, it is necessary to anchor the main sprocket 37 against rotation, or to drive it at a predetermined rate of speed through another gear or sprocket which is made a part of and concentric with its main sprocket. In the first instance, that is when the main sprocket is anchored against rotation, the rate of rotation of the motor and gear unit around the axis of the band wheel shaft is governed by the rate of rotation of the prime mover and the gear and sprocket ratios between the prime mover and the main sprocket. This rate of rotation can be changed only by changing the rate of rotation of the prime mover, or by changing the gear or chain ratios. In the latter instance, that is when the main sprocket is driven by a predetermined rate and direction of speed, by an auxiliary prime mover and gear unit, this predetermined rate of rotation of the main sprocket willgovern the rate of rotation of-the main motor and .gear unit'around the axis of the band wheel shaft. In this latter case, by using a variable speed mechanism for driving the main sprocket, the rate of rotation of the main motor and gear unit around the axis of the crank shaft can be easily and quickly changed. This change of speed possibility is a valuable asset to the operation of some wells.

When this mainsprocket is not formed integral with one of the shaft bearings, or designed to rotate as explained, it may be secured against rotation by a holding bracket 43 which is here indicated as comprising a radial arm 44, having a bolting pad at its outer end. This radial arm or mainv sprocket holding device may be held by a shock absorbing mediumif sofidesired'. For adding strength to the counterweight arm 38 and to provide convenient. bolting. spaces, the arm is formed with a plurality-of spaced longitudinal ribs 45 betweenwhich webs occur. Bolt holes 46 are formed through the: webs and mayreceiVe additional counterweight-blocks 47- which may be variably applied to. add further weight to the outer end of the arm as pumping conditions may require it.

The motor.2l receives its supply of electricity through a conduit 48; here. shown as enclosing the Wires 49 .of a 3-phase. electric circuit, and which wires connect separately with commutator rings 53, 54, and 55,- respectively; The commutator structure may be housed in. an-y suitable manner. Suitable conductors'ar-e connected with the several commutator rings and-are led along the counterweight arm-to connect to the binding posts of the motor2 1.

In the form of the device which has been described in the foregoing portionof the specification and which relates particularly-to Figs. 1 and 2 of the drawings, the counterbalanced motor drive is only intended for use at such times as a variable load driven structure is operated thereby. In well pumping operations, however, it some timesbecomes necessary to pullthe pump rods and tubing and perform othenhoisting duties in connection with, the well operation, andat such times the provision ofa counterbalance on the band wheel shaftis not desired. In order to meet such emergencies the present invention is embodied in the particular structures shown in Figs. 3 and 4 of thedrawings, This structure differs from that previously. described in that the counterbalance arm 38 is mounted on the outerend of the band wheelshaft 19 and may be optionally connected or disconnected from the shaft. The same object can beaccomplished with the counterbalance located aslin Figs. 1 and-2. The connection comprises-- a series of capscrews 56 which pass throughga. headportion- 57 carried by the band wheel shaft.'1-9, and'-' secure the bearing 58 of the counterweight "arm 38 to theshaft'to.

rotate therewith. When-however, the cap screws 56 are removed, the counterweight arm 38 will be idle and will. not driven-theband-wheel shaft 19. Band wheel shaft 19 may-thenbe driven in the conventional manner by'another prime mover and the hoisting may be accomplished by the usual calf wheel or bull wheel drive combinations.

By removing the fastening 59 by which gear 60 is normally held against rotation, and by providing another gear or sprocket made an integral part of and concentric with; gear 60, the motor unit 21 may be caused to drive the gear 60 and by connecting the integral gear or sprocket to suitable hoisting mechanism the motor unit 21 may be used for hoisting. I

Any suitable hoist mechanism may be placed in driving relation to the gear or sprocket which is integral with gear 60 or in relation to the motor unit drivingpinion when it is desired to do so, and may be operated thereby without in anywise effecting the rotation of the crank 19.

By referring to Fig. 3 of the drawings, it will also be seen that the gear train is somewhat different from that shown in Figs. 1 and 2 of the drawings, in that the outer end of the gear drive shaft 34 is provided with a sprocket wheel 61 which is disposed in the same plane with the sprocket wheel 62 and around both of which wheels a sprocket chain 63 is led. The sprocket chain 63 is mounted upon a jack shaft 64 suitably housed in a bearing 65 carried by the counterweight arm 38, and at the opposite end of which shaft is a gear pinion 66 which is in mesh with the large gear 60. This latter gear serves the same purpose as the main sprocket 3'7 previously described, and when it is constrained from rotation, the motor and gear unit together with the counterbalance arm will gyrate around the axis of the band wheel shaft.

In operation of the present invention, the devices are assembled as particularly shown in Figs. 1 and 3 of the drawings. After being properly assembled and installed on the jack posts of a well rig, the drive structure may be suitably connected with the pitman rod 1'7. The counterweight arm 38 is then properly positioned in correct relation to the main crank 18, and in order to give the most desirable counterbalance for the pump mechanism 14. Electric current may then be supplied through the commutator structures to the motor 20. This will cause the motor to drive its sprocket 35 through the gear reduction train enclosed within the housing 23 of the re-- duction gear unit 22. Due to the fact that the main sprocket 37 or the main gear 60 are restrained from rotation the driving action will cause the complete motor unit and its gear train to assume a planetary motion around the axis of the band wheel shaft 19. In doing this the counterweight arm will be given a gyrating motion and the weight of this arm and the mass supported thereby will properly counterbalance the variable reciprocating load of the pump 14. In the case where the main sprocket 3'7 is driven at a predetermined and governable rate of speed by an auxiliary driving mechanism instead of being constrained from rotation as described above, the motor unit and its gear train will still assume a gyrating motion around the axis of the band wheel shaft although this speed of movement will be relative to the speed at which the main sprocket is being driven.

The motor 21 may be of any design, but due to the fact that even on a properly counterbalanced well the power input to the prime mover may vary as shown in Fig. 8, better results and a smoother power curve may be obtained by use of a "high slip rotor motor. Its action is, that on the top and the bottom positions of the pump plunger, when there istheor'etically no input power required the high slip rotor motor speeds up the entire mechanical train, thus absorbing energy, while at the points in the cycle when the pump plunger is in the middle of its stroke when most of the power is required, the high slip rotor motor and its mechanical train is dragged or slowed down, and in so doing, gives up some of the energy stored up at the no load points. Thus the input power curve may be appreciably flattened and the mean average efficiency of the motor increased.

It will be evident that by use of such a mechanism as described, the mechanism may be fitted onto standard band wheel shafts and installed in existing jack post bearings, thus eliminating the necessity of making special heavy foundations for the motor and gear unit as is the case in conventional practice and making it possible to readily move the unit for installation at different points.

The operation of a necessary hoist at a well may also be accomplished in another manner. The counterweight arm with motor unit may be blocked with a blocking post of some suitable means in an approximately horizontal plane. The driving chain is disconnected, thus freeing the main sprocket or gear 60. The motor unit with its driving pinion is thus projecting towards the derrick floor and the drive chain can then be placed on the sprocket of a suitable hoist as shown. When power is turned on the motor unit in this position it drives the hoist instead of pulling itself and the crank around gear or sprocket 60 as it does during the pumping operation.

Attention is further directed to the fact that due to the construction here shown and its symmetry of action around the axis of the band wheel shaft, expensive and complicated pitman rod counterbalance structures, or other counterbalance structures are unnecessary, making it possible to utilize any pitman rod of simple construction by which the crank 18 may be properly connected with the walking beam.

In some instances it may be desirable to mount the motor on the side of the counterweight arm as indicated in Fig. 7 of the drawings. By this arrangement the effective amount of counterbalance can be easily obtained by fastening the motor at a desired point of radial adjustment on the arm.

While I have shown the preferred forms of my invention, as now known to me, it will be understood that various changes may be made in combination, construction, and arrangement of parts by those skilled in the art without departing from the spirit of my invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:--

1. In combination with a variable load device, means to counter-balance the same comprising a drive shaft, bearings rotatably supporting said shaft, power transmission means between the drive shaft and the variable load device, a counter-weight arm fixed upon the drive shaft and so set with relation to the variable load device as to be in a counter-weight position when the variable load device is under load, a motor mounted at the outer end of said counter-weight arm the weight of which motor adds counter-balanceto the arm and gearing driven by the motor whereby the arm will be caused to move in a gyratory path around the axis of the drive shaft and will simultaneously drive said shaft acting through the power transmission means to drive and counter-balance the variable load device.

2. In combination with a reciprocating pump mechanism, drive and counter-weight means therefor. including .a rotary drive shaft, power transmission means to translate the rotary motion of the drive shaft into the reciprocating motion of the pump mechanism. a counter-weight arm disposed radially of the drive shaft and fixed therewith,,an electric motor mounted upon the free end of the counter-weight arm to provide additional counter-balance for the arm, a gear disposed. concentric of the axis of the drive shaft andheld against rotation, gear means driven by the motor andin mesh with the first named gear whereby driving action of the motor will causelthe motor, and its gear means to travel around the fixed gear and the axis thereof to produce gyratory motion of the counter-weight arm and rotation of the drive shaft whereby the pump mechanism will be driven and the counter-weight arm and the weight of the motor will act during the load period of the pump to counter-balance the same.

3. In combination with a reciprocating pump mechanism, drive and counter-weight means therefor including a rotary drive shaft, power transmissionv means to translate the rotary mo tion of the. drive shaft into the reciprocating motion of the pump mechanism, a counter-weight arm disposed radially of the drive shaft and fixed therewith, an electric motor mounted upon the free end of the counter-weight arm to provide additional counter-balance for the arm, a gear disposed concentric of the axis of the drive shaft tory motion of the counter-weight arm and rotationof the drive shaft whereby the pump mechanism, will be driven and the counter-weight arm and the weight of the motor will act during the load period of the pump to counter-balance the 'same,land means for disconnecting the counterweight. arm from the drive shaft when desired.

4. In combination with a reciprocating pump mechanism, drive and counter-weight means therefor including a rotary drive shaft, power transmission means to translate the rotary motion of the drive shaft into the reciprocating motion. of the pump mechanism, a counter-weight arm disposed radially of the drive shaft and fixed therewith, an electric motor mounted upon the free end of the counter-weight arm to provide additional counter-balance for, the arm, a gear disposed. concentric of the axis of the drive shaft and held against rotation, gear means driven by the motor and in mesh with the first named gear whereby driving action of the motor will cause the motor and its gear means to travel around the fixed gear and the axis thereof to produce gyratory motion of the counter-weight arm and rotation of the drive shaft whereby the pumpmechanism will be driven and the counterweight arm and the weight of the motor will act during the load period of the pump to counterbalance the same, said motor being of the high sliptyp e whereby its driving action will be automatically retarded as sudden load is imposed upon the motor.

5. In combination a drive shaft, bearings rotatably supporting the same, a counterweight arm extending radially from saidshaft and fixed thereto, a prime mover mounted upon the free end of the counterweight arm, gearing disposed concentric to said shaft and held against movement with relation thereto, power transmission means connecting the gearing and the prime mover whereby rotation of the driving element of the prime mover will act, to cause the counterweight arm to gyrate around the axis of the shaft rotating the shaft as the power transmission means drives against the gearing, and means acting upon the power transmission gearing to produce a differential driving action between the prime mover and-the shaft.

6. In combination a drive shaft, bearings rotatably supporting the same, a counterweight arm extendingradially from said shaft and fixed thereto, a prime mover mounted upon the free end of the counterweight arm, gearing disposed concentric to said shaft and held against movement with relation thereto, power transmission means connecting the gearing and the prime mover whereby rotation of the driving element of the prime mover will act to cause the counter-:

weight arm to gyrate around the axis of the shaft rotating the shaft as the power transmission meansdrives against the gearing, and means adjustably disposing the prime mover upon the counterweight arm whereby different counterbalance effects may be obtained.

7. In combination a drive shaft, bearings rotatably supporting the same, a counterweight arm extending radially from said shaft and fixed thereto, a prime mover mounted upon the free end of the counterweight arm, gearing disposed concentric to said shaft and held against movement with relation thereto, power transmission means connecting the gearing and the prime mover whereby rotation of the driving element of the prime mover will act to cause the counterweight arm to gyrate around the axis of the shaft rotating the shaft as the power transmission means drives against the gearing, and additional weight meansadapted to be optionally mounted upon the counterweight arm to produce the desired counterbalance effect.

8. In combination a drive shaft, bearings rotatably supporting the same, a counterweight arm extending radially from said shaft and fixed thereto, a prime mover mounted upon the free end of the counterweight arm, gearing disposed concentric to said shaft and held against movement with relation thereto, power transmission means connecting the gearing and the prime mover whereby rotation of the driving element of the prime mover will act to cause the counterweight arm to gyrate around the axis of the shaft rotating the shaft as the power transmission means drives against the gearing, additional weight means adapted to be optionally mounted uponthe counterweight arm to produce the desired counterbalance effect, and means for moving said weights longitudinally of the arm and radially of the shaft to vary the counterweight action.

9. A driving mechanism for oil well rigs comprising a crank shaft, a crank thereon, a walking beam connected at one end with the crank to be operated thereby, connections from the opposite end of the walking beam extending into the well, a reciprocating pump structure actuated thereby, a driving motor, a rigid mounting for supporting the driving motor in concentric relation to the drive shaft, said mounting being fixed to rotate with the shaft and to cause the motor to pursue a concentric circular path of travel around the shaft, said motor being disposed in relation to the axis of the shaft to counterbalance the crank and the Walking beam, and a gear train in engagement with the motor and which will cause'the motor and its support to swing around and with the drive shaft as the motor is driven to drive the shaft and counter-balance the same.

10. A driving mechanism for oil well rigs comprising a walking beam, a connection at one end thereof extending into an oil well and operating a reciprocating pump mechanism, a drive shaft, a crank carried thereby and operatively connected at the other end of said Walking beam,

an arm fixed to and extending radially of said crank, a driving motor carried at the outer end of said radial arm, a fixed gear element disposed concentric with the axis of the drive shaft, and a gear train connecting said gear element and the motor whereby the driving operation of the motor will cause the motor to pursue a path around the axis of the drive shaft while driving the same, said motor being so set with relation to the crank on the drive shaft as to counter-balance the crank and walking beam by its weight.

WENDELL M. JONES.

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