US3453968A - Positive displacement pump - Google Patents

Description

July 8, 1969 Filed April 24, 1967 5. W. WORTLEY POSITIVE DISPLACEMENT PUMP Sheet Ora INVENT OR. STEWART W WORTLEY ATTORNE Y5 July 8, 1969 s. w. WORTLEY 9 3,453,968

POSITIVE DISPLACEMENT PUMP Filed April 24, 1967 INVENT OR. STEWART W. WORTL EY A TTO RNEYS July 8, 1969 s. w. WC 'JRTLEY POSITIVE DISPLACEMENT PUMP Filed April 24, 1967 Sheet INVENTOR. STEWART W. WORTLEY ATTORNE Y5 United States Patent Ofice 3,453,968 Patented July 8, 1969 3,453,968 POSITIVE DISPLACEMENT PUMP Stewart W. Wortley, 1814 S. Cheyenne, Tulsa, Okla. 74119 Filed Apr. 24, 1967, Ser. No. 633,156 Int. Cl. F04b 19/22, 1/16, 39/08 U.S. Cl. 103-157 9 Claims ABSTRACT OF THE DISCLOSURE Summary of the invention Most positive displacement pumps, by their nature, pump at a continuous rate. The only widely used present arrangement for varying the pumping rate of positive displacement pumps is by varying the speed of drive. This normally requires either a variable speed prime mover or some sort of variable speed transmission arrangement. Both of these are relatively expensive to provide and maintain. This invention provides a pump in which the pump rate is easily variable over a wide range even when driven by .a constant speed motor. In addition the pump is characterized by extreme simplicity and economy of construction so as to make it adaptable for a wide variety of applications. The pump includes an arrangement wherein a unitary valve structure functions both as an inlet and an outlet valve and wherein the valve system is totally contained within the pump cylinder. In

this pump the valve system is actuated simultaneously with the actuation of the piston so that no external valve linkages or other devices are required.

The pump of this invention, in one embodiment, includes a duplex arrangement wherein two cylinders are axially aligned and wherein the pistons are connected in axial relationship and reciprocated by a single power source. The invention is further characterized by the ease by which the volume of the pump may be varied and in the duplex arrangement wherein the volume of each portion of the pump may be individually adjusted while using the same power source.

Description of the views FIGURE 1 is a top elevational view of a duplex pump according to this invention including a driving motor.

FIGURE 2 is a perspective view of a duplex pump according to this invention having one cylinder of the pump shown in cut-away view so that the interior components thereof are disclosed.

FIGURE 2A is a cut-away view of one cylinder of a pump according to this invention.

FIGURE 3 is a partial perspective view of valve components and the valve actuating member according to this invention.

FIGURE 4 is a cross-sectional view taken along the lines 4-4 of FIGURE 1.

FIGURE 5 is a cross-sectional view of a pump chamber according to this invention similar to FIGURE 4 and showing a modified form of valve biasing members.

FIGURE 6 is a perspective view of a piston rod and piston assembly as used in a duplex pump of this invention.

FIGURE 6A is a perspective view of a modified form of piston rod and piston assembly according to this invention.

FIGURE 7 is a perspective view partly cut-away of a piston rod adjustment means.

FIGURE 7A is a top view showing the piston rod adjustment means of FIGURE 7.

FIGURE 8 is a crosssectional view taken along the line 88 of FIGURE 1 showing the relationship between the motor rotated crank arm and the pump drive extension.

FIGURE 9 is a view as shown in FIGURE 8 disclosing an improved embodiment of the invention wherein the displacement of the pump may be varied without changing the speed of rotation of the drive motor.

Detailed description The reciprocating piston pump of this invention will be described by reference to an exemplified embodiment showing the application of the principles of the invention to a duplex pump. The duplex pump includes a pair of coaxially aligned cylindrical chambers with each chamber having an inlet and an outlet port and a piston positioned therein. A single piston rod is in coaxial alignment with the chambers and is secured to each piston to reciprocate each piston within its own chamber. The piston rod has a perpendicular drive extension attached, at its outer end, to a crank arm rotated by a drive source, such as an electric motor. Within each chamber is a peripherally positioned valve member reciprocated arcuately to alternately open and close the inlet and outlet ports.

Referring now to the drawings and first to FIGURES 1 and 2, a pump embodying this invention is shown, comprising a housing generally indicated by the numeral 10, having a first cylindrical portion 12 and a coaxial second cylindrical portion 14. Each cylindrical portion 12 and 14 of the pump housing has a chamber or cylinder 16 therein. An end plate 18 closes one end of each chamber and provides access to each chambers interior. The other end of cylinder 12 is closed by a wall 20 and cylinder 14 is closed by wall 22. Wall 20 has an axial opening 24 therein reciprocally receiving a piston rod 26, and wall 22 likewise has an axial opening 28 reciprocally receiving piston rod 26. Secured to each end of piston rod 26 are piston members 30 and 32 (see FIGURES 6 and 6A), with only piston member 32 being shown in FIG- URE 2. Reciprocation of piston rod 26 with pistons 30 and 32 bring about the flow of fluid into and out of chambers 16 of cylinders 12 and 14 through ports 34, 36, 38 and 40.

Piston rod 26 has a drive extension 42 perpendicularly connected thereto including a ball member 44 at the outer end thereof. Ball member 44 is pivotally received in a recess 46 of a crank arm 48 secured to shaft 50 of motor 52. Thus, motor 52 causes crank arm 48 to rotate, and since extension arm 42 is received eccentrically in recess 46 in the crank arm, two motions are given to piston rod 26, that is, the piston rod is rectilinear reciprocated and at the same time is oscillated about its axis.

An extension sleeve 54 extends from piston 30 and likewise an extension sleeve 56 extends from piston 32, as shown in FIGURE 6, with FIGURE 2 showing only sleeve member 56. Extension sleeves 54 and 56 are semitubular in shape and preferably extend from pistons 30 and 32 adjacent the peripheral edge thereof. An enlarged diameter valve receiving recess 58 is provided in each cylinder in a plane perpendicular the cylindrical axis and in the plane of the valve ports. A semi-tubular floating valve member 60 having an external diameter equal to the internal diameter of recess 58 is slidably received within recess 58. Valve member 60 alternately closes ports 36 and 50 in response to oscillatory movement of sleeve 56 within chamber 16. Oscillatory movement of sleeve 56 about the axis of piston 32 alternately brings shoulder 62 of sleeve 56 into abutment with shoulder 64 of valve member 60 and shoulder 66 of sleeve 56 into abutment with shoulder 68 of valve member 60. It is not necessary that shoulders 62 and 66 be in continuous abutment against shoulders 64 and 68. That is, with shoulder 62 in abutment with shoulder 64, a space may exist between shoulder 66 and 68, and vice-versa. Although not shown, a valve member is provided in a recess in cylinder 12 as described with reference to cylinder 14.

Valve member 60 may operate in an unbiased condition within recess 58, but preferably, means is provided as described in FIGURES 2, 3, 4, and 5, whereby valve 60 is biased against the wall of recess 58. One means of effecting this biasing condition is shown in FIGURE 2 and with greater detail in FIGURE 3. A bolt member 70 extends through a threaded opening 72 in each cylinder 12 and 14 and through a slot 73 in each sleeve 54 and 56. Exterior of each cylinder a lock nut 74 is threaded onto the outer end of each bolt 70. The end of bolt 70 within each cylindrical chamber is received within a recess 76 in a bracket 78. As shown in FIGURES 3, 4, and 5, bracket 78 has pivotally attached thereto two supporting arms 80 which are held to bracket 78 by pins 82. At the other end of each supporting arm 80 is a reduced diameter portion forming a pin 84 which fits into a recess 86 in valve member 60. Pins 84 fit loosely enough so that pivotal movement is allowed. A coil spring 88 is compressibly received around each supporting arm 80 resiliently or yieldably urging valve 60 into sealing engagement with the cylindrical surface of recess 58. By adjustment of bolt 70 and lock nut 74, valve 60 may be brought into proper tensionable abutment against the wall of recess 58 in each chambered portion of the pump housing FIGURES 4 and show two means of attachment of supporting arms 80 to bracket 78. In FIGURE 4 each supporting arm 80 extends substantially across the circular bracket portion 78. In FIGURE 5 each supporting arm 80 is attached to brackets 78 at the nearest edge of brackets 78 to that particular supporting arm. FIGURE 5 also demonstrates the manner in which valve 60 moves so as to alternately cover port 36 and port 40. The rotation of crank arm 48 imparts, by way of drive extension 42, both a rectilinear and an oscillatory rotative movement to piston rod 26. The combination of the two modes of movement of piston rod 26 are further imparted to pistons 30 and 32 so that in one direction each piston will bring about a reduction in the volume of each piston chamber between the face of the piston and the end plate closing that chamber. That is, for example, when piston 32 moves to the right in FIGURE 2, the volume of chamber 16 described between the face 90 of piston 32 and in end plate 18 becomes smaller. The movement of each piston to reduce the volume of its chamber 16 described between the face 90 of piston 32 and in end plate 18 becomes smaller. The movement of each piston to reduce the volume of its chamber brings about the flow of fluid from that chamber when the chamber is initially filled with fluid. At the same time that piston 32 moves to the right to reduce the volume of chamber 16, rotative movement of piston 32 causes shoulder 62 of extension sleeve 56 to abut shoulder 64 of valve 60 and rotate the valve so that it closes the inlet port 36 and opens the outlet port 40.

The piston in cylinder 12 functions the same as the piston in cylinder 14 but in 180 phase relationship, that is, cylinder 12 discharges when cylinder 14 is on the intake cycle, and vice-versa. Piping connections from outlet ports 34 and 40 may be manifolded so that discharge of fluid from the two cylinders of the duplex pump is alternately obtained, thereby reducing outlet pressure pulsations. Inlet ports 36 and 38 may likewise be manifolded.

FIGURE 6A describes a modified form of piston rod, piston, and extension sleeve assembly in which extension sleeves 54 and 56 are on opposite sides of the respective pistons 30 and 32.

FIGURES 7 and 7A illustrate a means of adjusting the length of stroke of one of the pistons. The piston rod is made in two parts, identified as 26A and 26B. To piston rod 26A is secured a sleeve portion 96 which has attached thereto a first upstanding end bracket 98, a second upstanding end bracket 100 having threaded opening 114 therein. Paralleled and spaced apart wall portions 102 and 104 extend between and support end brackets 98 and 100, forming in effect, an open top and bottom box. A flattened portion 106 of piston rod 26B is slidably received within the confines of brackets 98 and 100 and walls 102 and 104. At the end of fiattened portion 106 is an integral perpendicular shoulder 108. A bolt 112 is threadably received within an opening 114 in bracket 100. Bolt 112 has an enlarged end portion 110.

FIGURE 7 shows the device wherein the bolt 112 is threaded as far as possible inward clamping the shoulder portion 108 against bracket plate 98. In this position the two piston rods 26A and 26B are locked together and are in effect the same as the prior disclosed arrangements such as shown in FIGURE 6. In this position of bolt 112 the same length of stroke is imparted to both piston rods 26A and 26B. However, if it is desired to shorten the length of stroke of piston rods 26A, bolt 112 can be backed off as shown in FIGURE 7A. It can be seen that in the mode of operation of FIGURE 7A the reciprocation of the piston rod extension 42 causes the piston rod 26B to move the full stroke thereof and this movement is transmitted to the shoulder 108. However, shoulder 108 is free to move between the confines of the interior wall of bracket plate 98 and the enlarged portion 110 on the end of bolt 112. Thus, as the piston rod 26B is moving in either direction no movement is imparted to piston rod 26A until the shoulder portion 108 has traveled the distance between the bracket plate 98 and the enlarged end 110 of bolt 112. By varying the position of bolt 112 the length of stroke of piston rod 26A can be adjusted to the full length of the stroke of piston rod 26B, as shown in the mode of FIGURE 7, or to only a friction of the stroke as shown in FIGURE 7A. It is noted that regardless of how far bolt 112 is retarded and thus the length of stroke of piston rod 26A is reduced in comparison to that of rod 26B, nevertheless the same degree of rotation of piston rod 26A is imparted and therefore the valve element associated with piston 30 is actuated through the arc necessary to open and close the ports on each stroke of the piston even though the pistin be displaced only a small portion of its full stro e.

In the embodiment shown in FIGURES 7 and 7A, the adjustability of the stroke of piston rod 26A is shown. It can be seen that by an identical device piston rod 26B may be equipped in the same way so that its stroke may be varied. By use of two such arrangements the stroke of each of the pistons of the duplex pump can be individually and independently adjusted. The embodiment of FIGURES 7 and 7A is only exemplary of the lost motion arrangement for varying the relative stroke lengths of the two pistons of the duplex pump of this arrangement. Obviously other arrangements may be devised in keeping with this concept and principle.

FIGURE 8 shows the crank arm 48 which is rotated by a shaft 50 extending from motor 52. Received in opening 48 is ball portion 44 at the outer end of the drive extension 42. In this simple embodiment the drive extension ball portion 44 is rotated in a plane causing the piston shaft 26 (see FIGURES 1 and 2) to reciprocate back and forth and at the same time oscillate. FIGURE 9 shows an alternate arrangement of the crank arm 48. In this arrangement a ball receiving element 90 is slidably received in a slot 92 formed in the crank arm. The ball receiving element 90 includes opening 46 which receives the ball portion 44 of drive extension 42. A threaded opening 94 in the outer end of the crank arm 48! receives a bolt 96 which in turn is rotatably affixed at its inner end to the ball receiving element 90. By threadable adjustment of bolt 96 the distance between the ball portion 44 and the shaft 50 is varied. It can be seen that the longitudinal motion imparted by the rotation of crank arm 48 to drive extension 42 is the diameter of the circle of the ball portion 44 as it rotates around shaft 50. A counter-balance weight 98 may be aflixed to the crank arm 48 opposite the ball receiving element, however, this is strictly optional.

The length of stroke of the piston rods 26A and 268 may be varied from a full to a relatively short stroke. The stroke, however, must not be so short that the axial rotation imparted to the shafts 26 is insufficient to rotate the valve element 60 beween positions to open and close the fluid ports. The amount of axial rotation required to move the valve members from open to closed position and vice-versa is only that required to cover or open the ports as the case may be and therefore it is related only to the diameter of the ports. Thus, the amount of axial rotation required to open and close the ports is relatively small which means that the stroke of the pump can be reduced to a very small amount by means of the arrangement of FIGURE 9. Of course, by incorporating the arrangement of FIGURE 9 with that of FIGURE the stroke lengths can be reduced to zero but still maintain the small angular rotation of the drive shaft 26 to open and close the ports.

It is important to note that the pump of this invention requires only a relatively small axial rotation regardless of the stroke length.

In the illustrated embodiments the ports 36 and 40 are shown as diametrically opposed. This is not a requirement of the pump as the ports may be located adjacent to each other in which case the valve element 60 would be of a much shorter circumferential length.

The improvements are shown in FIGURES 7, 7A and 9 by merely exemplary of the adaptability of the pump of this invention to various other improvements. The basic invention lies in the fundamental pump arrangements and many other improvements of the nature shown in these figures may be added without departing from the basic concept of the invention.

The invention has been described with a certain degree of particularity. It is understood that the invention is not limited to the abstract herein, to the summary of the invention nor to be detailed description of the exemplified embodiments.

What is claimed:

1. A positive displacement pump comprising a cylindrical housing having inlet and outlet ports provided in the cylindrical walls thereof, floating valve means disposed within said housing and having an. outer periphery of a configuration complementary with the inner periphery of the housing, yieldable means constantly urging said floating valve means into sealing engagement with the inner periphery of the housing, a reciprocal piston disposed within said housing, means carried by said piston for transmitting combined oscillatory and axially reciprocal movement thereto, and extension means c0- operating between the piston and the floating valve means for transmitting rotational movement only to the floating valve means whereby a first position of said floating valve means covers said inlet port and exposes said outlet port and a second position of said floating valve means covers said outlet port and exposes said inlet port for alternate opening and closing of said ports upon reciprocation of the piston.

2. A positive displacement pump as set forth in claim 1 wherein the rotational movement of said floating valve means comprises oscillation of said valve means about the longitudinal axis of the housing and between said first and second positions.

.3. A positive displacement pump as set forth in claim 1 wherein the extension means includes means for precluding longitudinal movement of the valve means within the housing for permitting reciprocation of the piston independently with respect to the valve means.

4. A positive displacement pump as set forth in claim 1 wherein the yieldable means comprises spring means interposed between the housing and floating valve means, said spring means providing a constant radially outward pressure of the floating valve means against the inner periphery of the housing for a sealing engagement therebetween.

5. A positive displacement pump as set forth in claim 1 wherein the extension means comprises longitudinally extending means carried by the piston and having slot means extending longitudinally therein for slidably receiving the yieldable means therethrough, said slot means cooperating with the yieldable means and floating valve means for precluding longitudinal movement of the floating valve means while providing oscillation thereof between said first and second positions.

6. A positive displacement pump as set forth in claim 1 wherein said means for transmitting combined oscillatory and axially reciprocal movement to the piston comprises a rod member extending radially outwardly from said piston and through said housing, a prime mover having a rotatable drive shaft, crank arm means connecting said prime mover with said rod member whereby said piston is simultaneously oscillated and axially reciprocated upon rotation of said drive shaft.

7. A positive displacement pump as set forth in claim 6 wherein means is provided for cooperating between the drive shaft and crank arm means for varying the longitudinal reciprocation of said piston.

8. A positive displacement pump as set forth in claim 1 wherein the floating valve means comprises a first floating valve mechanism disposed on one side of said piston and a second floating valve mechanism disposed on the opposite side of said piston, and said yieldable means comprises independent spring means interposed between the housing and each of said floating valve mechanisms for urging said floating valve mechanisms into sealing engagement with said housing.

9. A positive displacement pump as set forth in claim 8 wherein said extension means comprises oppositely disposed longitudinally extending members carried by the piston and each having slot means extending longitudinally therein for slidably receiving the yieldable means of the respective floating valve mechanism therethrough,

References Cited UNITED STATES PATENTS 1,384,941 7/1921 Dilley 103-227 1,872,503 8/1932 Repschleger et a1. 103171 2,034,964 3/1936 Thompson 103-171 2,166,111 7/1939 Bancroft 103157 2,291,889 8/1942 Evans et al. 10338 2,538,463 1/1951 Lloyd 103157 12/1958 Tursky 103171 2/1965 Pinkerton 103157 8/1919 Dourte 103-l57 8/1966 Wortley 103-157 FOREIGN PATENTS 5 1919 Great Britain. 1/ 1959 Great Britain. 8/1922 France.

10 WILLIAM L. FREEH, Primary Examiner.

US. Cl. X.R.

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