US2539339A

US2539339A - Controlling device for pumps

Info

Publication number: US2539339A
Application number: US663531A
Authority: US
Inventors: Alexey J Stepanoff
Original assignee: Ingersoll Rand Co
Current assignee: Ingersoll Rand Co
Priority date: 1946-04-19
Filing date: 1946-04-19
Publication date: 1951-01-23
Anticipated expiration: 1968-01-23

Description

Patented Jan. 23, 1951 GONTROLBING DEVICE FOR PUMPS Alexey J. Stepanoff, Phillipsburg, N. J assignor to Ingersoll-Rand Company, New York, N. Y., a corporation of New Jersey Application April 19, 1946, Serial No. 663,531

This invention relates to pumps, and more particularly to a controlling device for changing the angular relationship of the pump vanes with respect to the direction of fluid flow through the pump.

One object of the invention is to selectively vary the impelling effect of the pump in accordance with immediate requirements or conditions of operation.

Another object is to enable the impelling effect of the pump to be thus varied at a point remote from the pump impeller and with a minimum of manual effort.

A more specific object is to avoid the overloading of the motor driving the pump when operating at reduced capacity.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals refer to similar parts: v t

Figure 1 is an elevation of a centrifugal pump equipped with a controlling device constructed in accordance with the practice of the invention,

Figure 2 is an elevation, partly in section, showing an enlarged view of a portion of the pump, and

Figure 3 is a transverse view taken through Figure 2 on the line 3-4.

Referring more particularly to the drawings, the-pump designated, in general, by 20 is shown extending into a pit 2| defined by a foundation 22 for removing liquid 23.

The pump casing 24 is formed in sections some of which lie within the pit 2| and one section, designated 25, has a flange 26 to seat on the foundation 22 and supports a motor only the casing 21 of which is shown. The pump is of the vertical type and the lowermost end of the casing 24 is flared outwardly to define an inlet opening 2| for the passage of liquid from the pit 2| into the casing 24. The outlet conduit 29 for the pump is shown as leading from the casing section 25.

Within the casing 24 is a series of support members 39 which are connected to the casing by ribs II, and the uppermost support member 39, of those shown, contains a bearing 32 for a pump shaft 39 that may be secured in any suitable manner to the shaft of the driving motor. The shaft 33 terminates between the support members II and extends at its lower end into a hub 34 that is secured to a flange I on the shaft by bolts 48. L

The hub 34 comprises a casing 41 of generally 6 Claims. (Cl. 103-89) cylindrical shape that is closed at its upper and lower ends, respectively, by cover plates 38 and 39 fastened to the casing 31 by screws 49. On the cover plate 38 is a depending skirt 4| having apertures 42 that are axially aligned with similar apertures 43 in the casing 31 to serve as bearings for trunnions 44 of the pump vanes 45, and between each trunnion 44 and its vane is a collar 46 that lies in a recess 41 in the outer surface of the casing 31 to prevent movement of the vanes in the direction of the axis of the pump.

v The trunnions 44 are rotatable in the apertures 42-43 to change the pitch of the vanes, and such movement is efiected by a fluid actuated piston 48 reciprocable in a piston chamber 49 in the casing 31 and operatively connected to the vanes in such wise that all the vanes will be rotated about their axes in unison and in equal degree. To this end, the piston is provided on its upper surface with an extension 59 that is slidable on the skirt 4| and has slots 5| in its outer surface to receive the ends of crank pins 52 seated in collars 53 on the trunnions 44.

Each collar 53 bears against the inner surface of the casing 31 and has an annular sleeve portion 54 that encircles the trunnion to serve as a renewable wearing surface therefor. The collars are secured to the trunnions by pins 55, and the sleeve portions 54 extend through the apertures 56 in the extension 59 for engagement with the skirt 4|. Theapertures 56 are of oblong shape to permit of endwise movement of the extension 50 with respect to the skirt 4| and their vertical side surfaces have a slide fit on the sleeve portions 54 so that the piston will rotate with the shaft.

The piston 48 is located in the lower portion of the casing 31, below the trunnions 44, and its lowermost pressure surface 51 and an elevated portion 58 of its upper pressure surface 59 cooperate, respectively, with a seating surface 60 on the cover plate 39 and a seating surface 6| at the lower end of the extension 4| to limit the stroke of the piston 48.

extends through the piston 48 and opens into the piston chamber 49 above the piston 48 which carries a sealing member 85 to prevent the leakage of fluid along the cooperating surfaces of the tubes and the piston.

The

tubes

62 and 83 are threaded at their lower ends into a fitting 68 on the support member 38 and communicate, respectively, with recesses 61 and 68 in said fitting. Motive fluid for moving the piston 48 upwardly is conveyed to the recess 61 by a conduit 69 connected to a control valve mechanism Hi to which motive fluid is delivered by the discharge conduit II of a pump 12 the inlet pipe 13 of which extends into a reservoir 14 containing a liquid I5, oil for example.

The valve mechanism 18 comprises a chest 18 havin a passage H in constant communication with the conduit II and with the opposed ends of a valve chamber 18, and motive fluid flows through an end portion of the valve chamber to the conduit 89. Communication between the said end of the passage 11 and the conduit 69 is controlled by a flange 19 of a reciprocatory valve 88 and said flange also controls communication between the conduit 69 and a conduit 8| leading from the intermediate portion of the valve chamber 18 to the reservoir 14. The valve 88 also controls the motive fluid serving to cause movement of the piston 48 in a downwardly direction and accordingly has a second flange 82 to valve fluid from the passage 11 through the other end of the valve chamber I8 to a conduit 83 and to control communication between the conduit 83 and the conduit 8|.

The valve is shifted to its controlling position by

solenoids

84 and 85 the armatures of which are not shown but may be connected to stems 88 on the valve projecting through the end walls of the valve chest 16. The

solenoids

84 and 85 are, respectively, provided with electric circuits 8! and 88 each having a switch 89 to control the flow of current to the solenoids from a circuit 98 for the motor 9I which drives the pump 12. The circuit 98 also has a switch 92 for controlling the operation of the motor.

The conduit 83 controlled by the valve head 82 leads from the valve chest 16 to an end 93 of a cylinder 94 which is of a volume equal to the amount of fiuid displaced by the piston 48 during its full upward stroke in the piston chamber 49. The opposite end 95 of the cylinder 94 is in constant communication with the recess 88, and thus with the upper portion of the piston chamber 49, through a conduit 98.

Within the cylinder 94 is a plunger, or piston. 91 having a rod 98 extending slidably through a stufllng box 89 in the end of the cylinder 94 to actuate an indicating device designated, in general, by I88 and serving to indicate the pitch of the vanes 45. The indicating device I88, and which may be of any suitable type, comprises a dial I8I having markings I82 thereon to indicate different angular positions in which the vanes may be placed for varying their impelling effect. The dial IOI is mounted upon a bracket I83, and a shaft I84 journaled in the bracket extends axially through the dial IM and carries a pointer I85 for cooperation with the markings I82. The shaft I84 also carries a pinion I88 that meshes with the teeth of a rack I81 on the rod 88 for rotating the pointer I85.

The valve mechanism 18 controls the flow of motive fluid only to and from one end of the piston chamber 49 and of the cylinder 94, and in the conduit 86 and the other ends of thepiston i chamber and the cylinder 94 is a constant volume or body, of oil to transmit movement from the piston 48 to the plunger 81 and, conversely. to transmit movement from the plunger to the piston. Such oil is delivered to these chambers by a conduit I88 leading from the conduit H to the conduit 88 and a check valve I89 in the conduit I88 is biased to pass oil only in the direction of the conduit '86 and to open for that purpose only at a pressure somewhat higher than that supplied to the piston chamber 49 and the cylinder 94 through the valve mechanism 18.

In order to avoid the introduction of oil into the conduit 96 and the associated chambers at pressures in excess of that through which the check valve I89 is set, the conduit 98 is provided with a discharge conduit II8 having a relief valve III, of any suitable type, that operates at the pressure at which the check valve I89 opens to permit the escape of oil from the conduit 96 to the reservoir. Preferably, the discharge conduit II is also provided with a branch II2 that leads to the reservoir 14 and has a relief valve I I3 therein adapted to open at a pressure somewhat in excess of the maximum pressure of the fluid required for rotating the vanes to avoid subjecting the fluid conducting system to unnecessarily high pressures.

The operation of the device is as follows: Whenever it is intended to decrease the pitch of the vanes 45, and with the pump 12 in operation, the circuit 81 is closed, by means of its switch 89, and the solenoid 84 will then pull the valve 88 toward the right to communicate the left-hand end of the passage 11 with the conduit 69. Motive fluid then flows through the end of the valve chamber and the tube 82 into the lower end of the piston chamber 49 and moves the piston 48 upwardly, thereby rotating the vanes 45.

During such movement of the piston 48, the fluid passes from the upper portion of the casing 31 through the tube 63 and the conduit 98 into the end 95 of the cylinder 94 and shifts the plunger 91 to rotate the pointer I and to expel fluid from the end 93 of the cylinder 94 through the conduit 83, the valve chest 76 and the conduit 8I to the reservoir 14. When the pointer reaches a marking I82 corresponding to the desired pitch of the vanes the switch 89 is opened and the solenoid 84 is thereby deenergized. The armature of the solenoid 84 and valve 88 will then return to neutral positions and cut off the flow of fluid from the pump through the valve mechanism 18.

Whenever it is desired to increase the impelling effect of the vanes 45, the switch 89 of the circuit 88 will be closed to cause the armature of the solenoid 85 to shift the valve 88 leftward and uncover the conduit 83. Fluid will then flow from the passage 11 through the right-hand end of the valve chamber 18 and the conduit into the end 93 of the cylinder 94. The plunger 91 is moved thereby in the direction of the end 95 and the fluid thus expelled from the cylinder 94 passes through the conduit 98 and the tube 83 into the piston chamber 49, above the piston 48, and forces the latter downwardly to tilt the vanes 45 to a steeper pitch.

During such downward movement of the piston 48 the fluid it displaces passes through the tube 62 and the conduit 89 and through the valve chamber between the flanges I8 and 82, thence through the conduit 8 I to the reservoir 14. When the vanes 45 have been rotated to the desired position. as indicated by the pointer ll! on the dial III, the switch I! is opened to deenergize the solenoid 85. The valve 80 will then again return to a neutral position and cut on the further flow of fluid through the valve mechanism. As will be readily appreciated, owing to the heavy pressure required for rotating the vanes, some of the fluid pushed back and forth by the piston Cl and the plunger 91 may escape along their surfaces so that its volume is reduced. The driven piston will then short-stroke and the position indicated by the pointer I05 will not be a true indication of the pitch of the vanes. In order. therefore, to minimize the chances of error incident to such leakage the pump 12 is continued in operation after the flow of fluid through the valve mechanism has been cut off, and when the discharge pressure exceeds the value for which the valves Hi9 and Ill have been set make-up fluid will flow through the conduit 96 and cause the driven piston to complete its stroke. If, on the other hand, the body of fluid between the pistons should become increased through.

linkage along the driving piston, and in consequence of which the driven piston completes its full stroke ahead of the driving piston, the latter is actuated to the end of its stroke by the continued application of driving fluid thereto and the fluid in excess of normal requirements will thereby be ejected from the conduit 96 through the relief valve ill and the conduit ill! to the reservoir II.

From the foregoing description it will be readily apparent that, irrespective of the nature of any variations in the volume of the fluid between the pistons, both pistons may be conveniently brought to definitely known positions prior to each blade-tilting operation, and a subsequent setting of the vanes may then be effected with little or no error between their actual positionand that indicated by the pointer on the dial itll I claim:

1. In a controlling device, the combination of a pump casing and a rotary shaft therein, vanes on and rotatable with respect to the shaft, a piston for rotating the vanes having opposed pressure surfaces. indicating means for indicating the pitch of the vanes, a plunger operatively connected to the indicating means and having opposed'pressure surfaces, means for communicating one pressure surface of piston and of the plunger, means for maintaining a constant volume of liquid between the last said surfaces for transmitting movement from the piston to the plunger and vice versa, and means for selecthe piston and of the plunger to motive liquid for rotating the vanes.

2. In a controlling device, the combination of a pump casing and a rotary shaft therein, vanes on and rotatable with respect to the shaft, a piston chamber having a piston therein for rotating the vanes, indicating means for indicating the pitch of the vanes, a cylinder of the same volume as the piston chamber, a plunger in the cylinder for effecting operation of the indicating means, a conduit to afl'ord constant communication between one end of the piston chamber and one end of the cylinder, means for maintaining a constant volume of liquid in the conduit and in said one end of the piston chamber and the cylinder for transmitting movement from the piston to the plunger and vice versa, and means for selectively subjecting another pressure surface of the piston and of the plunger to motive liquid for rotating the vanes.

3. In a controlling device, the combination of a pump casing and a rotary shaft in the casing. vanes on and rotatable with respect to the shaft, means on the shaft to provide a piston chamber, a reciprocatory piston in the piston chamber to rotate the vanes, indicating means located at a point remote from the vanes for indicating the pitch of the vanes, a cylinder of the same volume as the piston chamber, a plunger in the cylinder for effecting operation of the indicating means, a conduit to afford constant communication between one end of the piston chamber and of the cylinder, a predetermined volume of liquid in the conduit and in the said one end of the piston chamber and the cylinder for transmitting movement from the piston to the plunger and vice versa, means for replenishing such volume of liquid to compensate for leakage of liquid from said one end of the piston chamber and the cylinder, and means for selectively subjecting another pressure surface of the piston and of the plunger to motive liquid for rotating the vanes.

4. In a controlling device, the combination of a pump casing and a vertical rotary shaft therein, vanes on and rotatable with respect to the shaft, means at the lower end of the shaft having a piston chamber therein, a reciprocatory piston in thepiston chamber for rotating the vanes, conduits entering into the lower end of the casing and communicating the opposed end portions of the piston chamber with a source of liquid under pressure, a valve in said conduits for controlling the direction of flow of motive liquid through the conduits, a cylinder in one of said conduits, a plunger in the cylinder, a constant volume of liquid between the ends of the piston and plunger communicated by one of said conduits, and means actuated by said plunger for indicating the pitch 'of the vanes.

5. In a controlling device, the combination of a pump casing and a rotary shaft therein, vanes on and rotatable with respect to the shaft, means on the shaft for defining a piston chamber, a reciprocative piston in the piston chamber for rotating the vanes and having opposed pressure surfaces, indicating means for indicating the pitch of said vanes, a pump, valve means for tively subjecting another pressure surface of directing the flow of liquid from said pump, a pair of conduits communicating said surfaces with said valve means, a cylinder in one of said conduits, a plunger in the cylinder connected to saidindicating means, a conduit connected between one of the first said conduits and the discharge side of said pump, a check valve in the last said conduit, a conduit connected between the intake side of said pump and one of the first said conduits, and a relief valve in the last said conduit.

6. In a controlling device, the combination of a pump casing and a rotary shaft therein, vanes on and rotatable with respect to the shaft, means on the shaft defining a piston chamber, a reciprocative piston in the piston chamber for rotating the vanes and having opposed pressure surfaces, indicating means for indicating the pitch of said vanes, a pump, valve means for directing the flow of liquid from said pump, a pair of conduits communicating said surfaces with said valve means, a cylinder in one of said conduits, a plunger in the cylinder connected to said indicating means, a conduit communicating the discharge side of said pump with one of the first said conduits, a

1 pass liquid from the pump whenever the pres- REFERENCES CITED sure on the downstream side of said check valve The following references of record m the exceeds the value of the pressure required to actuate said piston, a conduit communicating the of this patent intake side of said pump with one of the first said 5 UNITED STATES PA'I'ENTS conduits. and a relief valve in the last said con- Number Name Date duit biased to pass liquid to said inlet side at the 1377.048 Sept. 13, 1932 opera ing pres r of said check valve. 1,952,566 Ring Man 1934 2,227,417 Ring et al Dec. 31, 1940 ALEX SIEPANOFF- 2.231.292 Neugebauer Feb. 11, 1941 2. 57.228 Seewer Aug. 29, 1944