US3172368A - Pump - Google Patents

Description

March 9, 1965 w. H. MASHINTER PUMP 3 Sheets-Sheet 1 Original Filed July 24, 1958 WWW wmm

BY film m),

PUMP

3 Sheets-Sheet 2 Original Filed July 24, 1958 w W W 0 7 .U y @mW March 9, 196 w. H. MASHINTER 3,172,363

PUMP

Original Filed July 24, 1958 3 Sheets-Sheet 3 t 45 INVENTQR.

States are The present invention relates to a novel fluid pumping structure. This is a division of my copending application Serial No. 750,760 filed July 24, 1958, now Patent No. 3,070,030.

The present invention relates particularly to positive displacement pumps suitable for a wide variety of uses as well as for installation in the specific pumping structure disclosed in the aforementioned copending application. It is an important general object of the present invention to provide a novel pump capable of relatively accurately and efliciently providing a variable output while at the same time being constructed in a manner which promotes more economical production.

An object of the present invention is to provide a novel fluid pump including reciprocable piston means actuated by rotary cam or Wobble plate means on a rotary shaft, which pump is constructed so as to eliminate any need for heavy thrust bearings for the shaft.

Another object of the present invention is to provide a novel fluid pump or driver including reciprocable piston type pumping means, which pump is constructed so as to start pumping action when the piston means has Zero velocity whereby to obtain a substantially shockless pumping station.

Further object of the present invention is to provide a novel fluid pump or driver of the above described type which is constructed so as to provide a substantially constant fluid flow or output.

Still another object of the present invention is to provide a novel fluid pump utilizing reciprocable piston pumping means, which pump is adjustable so that the output thereof may be varied in infinite increments and so that complete filling of pumping chamber means during each stroke of the piston means is obtained regardless of any adjustment for controlling the output whereby a substantially constant compression ratio and more uniform and etlicient pumping action are obtained.

A more specific object of the present invention is to provide a novel fluid pump which is constructed so that when it is adjusted for reducing the fluid output, a portion of the fluid will be circulated within the pump so as to reduce agitation of the fluid and power losses.

Still another object of the present invention is to provide a novel pump including a plurality of reciprocable piston means, which pump is constructed so that a single element controls the output of all of the piston means whereby construction is simplified and made more economical and close manufacturing tolerances are not required since any error in the control element will be introduced into the output of all of the piston means.

Qther objects and advantages of the present invention will become apparent from the following description and the accompanying drawings wherein:

FIG. 1 is a sideelevational view showing a pumping structure including a pump or driver incorporating features of the present invention;

FIG. 2 is a front elevational view partially broken away for showing certain features of the pumping structure;

FIG. 3 is an enlarged sectional view showing fluid pump or driver means constructed in accordance with features of the present invention and adapted to be installed in the pumping structure shown in FIGS. 1 and 2;

FIG. 4 is an enlarged fragmentary sectional view taken generally along line 4-4 in FIG. 1;

3,172,358 Patented Mar. 9, 1965 FIG. 5 is a cross sectional view on a reduced scale taken generally along line 5-5 in FIG. 3;

FIG. 6 is a fragmentary partial sectional view taken generally along line 6-6 in FIG. 3;

FIG. 7 is a fragmentary cross sectional view taken along line 7-7 in FIG. 6; and

FIG. 8 is a perspective view showing a control element of the fluid pump or driver structure constructed in accordance with features of the present invention.

Referring now more specifically to the drawings, wherein like parts are designated by the same numerals throughout the various figures, a pumping apparatus 30 including a pump 36 incorporating features of the present invention is shown generally in FIGS. 1 and 2.

The apparatus 30 is one installation in which the pump 36 is of particular value, but it is to be understood that the pump 36 is suitable for various uses. For a complete disclosure of the apparatus 30 reference is made to the above mentioned copending application. It suflices to state here that the apparatus 30 comprises an upstanding frame 32 which provides a sump or reservoir 34 for actuating fluid or hydraulic oil which is to be pumped in the manner described below. In order to provide suflicient power for enabling the pumping apparatus to deliver relatively high volumes of fluid without unduly increasing the size and weight of the apparatus, the high speed fluid pump or driver means 36 is mounted within the reservoir 34. A high speed electric motor 33 or other suitable prime mover is mounted on the frame 32 for actuating the pump 36. As indicated in FIGS. 1 and 3, an output shaft 4-6 of the motor is connected with a rotatable shaft 42 of the driver by suitable coupling means 44. It will be understood that in other types of installations, different means may be provided for driving the pump shaft 42.

The pump 36 is adapted to deliver a continuous and substantially constant stream of fluid or oil under pressure. This stream of fluid is directed by conduits 46 and 43 to a diaphragm pump assembly 50 which is secured to a side of the frame means 32. As is described in the aforementioned copending application, the pump assembly 50 is adapted to be actuated by the fluid under pressure from the pump36.

Referring particularly to FIGS. 1 and 3 through 8, the pump 36 will now be described in detail. The pump is provided with a main body member 52 having a central aperture 54 through which the rotatable shaft 42 extends. Cylindrical members 56 and 58 are respectively disposed against ends of the body member 52 and provide annular chambers 66 and 62 which are traversed by opposite end plates 64 and 66. The end plate 64 and the cylindrical member 56 are secured to the body member 52 by a plurality of screws 68. The end plate 66 and the cylindrical member 58 are similarly secured to the body member by a plurality of screws 70. Bearing assemblies 72 and 74 are mounted in suitable recesses provided in the end plates 64 and 66 respectively for rotatably supporting the shaft 42. It is to be noted that the structure does not include any heavy or substantial thrust bearing means for preventing axial shifting of the shaft 42 whereby the structure is simplified and made more economical. This feature is one result of other features described in detail below.

As shown in FIGS. 3 and 5, the body member 52 is provided with a plurality of piston accommodating bores or pump chambers 76 equally spaced about the axis of the body. Preferably there is an odd number and at least three of these bores and associated piston pumping means since such an arrangement facilitates phasing of the pumping action of the piston means associated with each bore so that the driver is capable of delivering a substantially continuous and constant stream of fluid. Opposed pis- 3 tons 78 and 80 are reciprocably mounted in opposite end portions of each of the bores 76. Inlet openings or passageways 82 are provided in the body member 52 for each of the bores 76, which passageways are located midway between the opposite ends of the bores '76 and communicate with the central bore or chamber 54 of the body member. Preferably the driver 36 is adapted to be mounted substantially completely submerged in the body of oil in the reservoir 34. Thus, oil from the reservoir will flow into the driver and completely fill the chambers 6t), 62 and 54 so that a supply of oil is available for entering the inlet ports 82. The opposite end assemblies of the driver are not fluid-tight so that oil may readily enter the driver chambers 60 and 62, and if desired openings, not shown, may be provided through the end plates 64 and 66 to facilitate entry of the oil into the driver. The body member 52 is provided with a plurality of outlet passageways 84 which extend radially from the bores 76 and are located so as to communicate with the bores midway between their opposite ends. The outer ends of the passageways 84 are respectively closed by plugs 86 I and communicate with upwardly extending outlet ports 83.

The outlet ports 88 are provided in a radially extending flange portion 90 of the body member 52 on which there is disposed a valve ring 92. The ring 92 is provided with a plurality of valve chambers 94 respectively communicating with the outlet ports 88. A flat centrally apertured valve seat member 96 is provided in each chamber 94 and a flat one way check valve 98 is also provided in each chamber for permitting fluid to flow from the outlet ports and through the valve chambers while preventing reverse flow of the fluid. Preferably springs 100 are provided for resiliently biasing the valve members 98 to closed positions. The outlets of the valve chambers 94 communicate with an annular manifold 102 provided in a ring member 1% mounted on top of the annular member 92. The annular members 104 and 92 are secured to the flange 90 by means of a plurality of screws 106 indicated in FIG. 5. The manifold 102 has an outlet connected with the above mentioned pipe 46 which directs the fluid discharged from the driver to the pumping assembly 50.

In order to actuate the pairs of opposing pistons 7 8 and 80 in the various bores 76, cam or wobble plates 108 and 110 are keyed or otherwise fixed to opposite end portions of the shaft 42 within the chambers 60 and 62 respectively. Preferably lock rings 112 and 114 are provided between the cam plates and the adjacent bearing assemblies 72 and 74. In addition, hardened wear resisting annular facing elements 116 and 118 are preferably provided over the cam faces of the cam members 108 and 110 respectively. Bearing slide blocks 120 are respectively provided between the piston '78 and the cam element 116, and similar bearing slide blocks 122 are provided between the ends of the pistons 80 and the cam element 118. It will'be noted that each of these blocks has a spherical seat 124 for accommodating a rounded end 126 of an associated piston. These blocks are free to slide over their associated cam elements 116 and 118 as the cam elements are rotated by the shaft 42. Of course, relative sliding action will take place between the bearing blocks and the rounded ends of their associated pistons. The bearing blocks are maintained in assembled relationship between the cam elements and the pistons merely by the clamping pressure exerted through the pistons, which clamping pressure is provided by springs 128 between each pair of opposing pistons and by the fluid pressure created during a pumping operation.

It is important to note that the cam plates 108 and 119 are formed and connected to the shafts 42 so that their opposing annular cam faces provided by the elements 116 and 118 are disposed in planes inclined at identical but oppositely arranged acute angles with respect to thelongitudinal axis of the shaft 4-2. In other words, the cam plates are oppositely disposed so that they will serve to actuate each pair of pistons 78 and in opposing relationship. For example, with the elements in the positions shown in FIG. 3, the pistons '78 and 80 at the lefthand side of the drawing are aligned with the lowermost portions of the cam surfaces so that both of these pistons are fully retracted or, in other words, these pistons have completed their suction strokes and are ready to begin their pumping strokes. It will be appreciated that as the cam plates are rotated, theopposing pistons will be axially shifted toward each other in unison so as to pump fluid which has been sucked into the bores '76 outthrough the associated discharge passageways and check valve chambers 94. It is important to note that during such a pumping operation, the axial thrusts exerted on the cam plates 1G8 and will be equal and oppositely directed. As a result of the fact that both carn thrust loads are absorbed in the common shaft none of the thrust load is transferred to the housing, thus obviating the necessity for thrust bearings.

In accordance with another important feature of the present invention, the driver is provided with a novel construction for controlling the pumping operation of the various pistons. More specifically, a rotary valve member 130 is mounted on the shaft 42 and secured against rotation relative to the shaft by an elongated key 132. However, the valve member 130 is adapted to be shifted axially of the shaft 42 in the manner described below for adjusting the output of the driver. As shown in FIGS. 3, 6, 7 and 8, portions of the peripheral'surface of the valve member 130 are cut away as at 134, 136, 138, and 142 so as to provideifiuid passageway means communicating with the chambers 60 and 62 within the driver and also adapted to communicate with the inlet ports 82 of the various pumping chambers or bores '76. The valve member is provided with a scroll 144 having a helical edge 146, which scroll is adapted to cover and seal the inlet ports 82 in a predetermined manner so as to control the pumping action.

The construction and arrangement of the valve member 130 is correlated with the construction and arrange ment of the cam plates 108 and 110 so that the inlet ports 82 are respectively uncovered by the scroll 144 during substantially the entire suction stroke of the piston means respectively associated with the various inlet ports 82. It is understood of course that the various inlet ports will be successively opened as the valve member 131 rotates and the various piston means will be succesively actuated through their suction strokes. However, the construction may be such that some overlapping in the suction and pumping operation of successive piston means may be obtained for promoting the discharge of a continuous stream of fluid. It will be appreciated that since the inlet port for each pumping chamber is openduring the entire suction stroke of its associated piston means, each pumping chamber will be completely filled with fluid or oil. This promotes more efiicient operation and enables the rate of discharge of the pumping mechanism of the driver to be accurately controlled.

It is also important to note that when a port 82 is uncovered so as to terminate pumping of fluid through an associated outlet 84, fluid will be forced from the associated chamber back into the cavity or reservoir between thevalve member 130 and the member 52. The construction is such that when'ithis occurs, the pistonsin an adjacent chamber having an uncovered port 82 are starting their suction strokes. Thus, excess fluid spilled under pressure from one chamber serves to help fill an adjacent chamber and to prevent cavitation so as to insure complete filling of the chambers.

In accordance with a feature of the present invention, the pump 36 is constructed so that a substantially shockless pumping action may be obtained. More specifically, the scroll 144 on the valve member 130 is positioned so that when, for example, the piston elements shown at the lefthand side of FIG. 3 have completed their suction strokes and have not yet started their compression strokes so that they are at a standstill, the scroll will accomplish complete closing and sealing of the inlet port 82 associated with these pistons. Thus, when these pistons begin their pumping strokes, compression of the fluid begins immediately. In other Words, the pumping action starts with the pistonsat zero velocity so that any possibility of the occurrence of substantial shock is eliminated. Of course the structure is such that the remaining pistons function in an identical manner.

Referring again to the pistons 78 and 80' at the lefthand side of FIG. 3, it will be appreciated that as the cam plates continue to rotate from the positions shown, these pistons will be advanced toward each other so as to pump the fluid from the bore 76 and out through the associated check valve chamber 94. In accordance with the present invention, this pumping action will continue until the inlet port 82is uncovered by the land or scroll 144 of the valve member 130 whereby to relieve the pressure Within the chamber 76. More specifically, the pumping action will continue until the valve member 138 has rotated sufficiently to cause either the helical edge 146 of the land or the narrow end 148 of the land to pass the inlet port 82 so as to uncover the port. It will be appreciated that the length of the pumping action may be varied even though the piston strokes remain constant by axially adjusting the valve member 130 to change the time at which the helical land edge 146 passes the port 82. In the position shown in. FIG. 3, the valve member 138 is substantially at. its uppermost position so that the full circumferential extent of. the land 144 will serve to close the port 82 and thereby provide for maximum pumping action and output. Upon lowering of the valve member 130 from the position shown, the helical edge of the land will be disposed so as to traverse the port 82 at any desired time, to shorten the length of the pumping action and thereby reduce the output of the driver. It is to be appreciated that the structure just described permits substantially infinite variations in the output of the pump 36 between zero output and maximum delivery. While the operation of the pistons at the lefthand side of FIG. 3 and the manner in which the pumping action thereof is controlled by the valve 130 has been described, it is to be understood that the remaining pistons of the pump 36 are identically actuated and controlled.

In order to facilitate adjustment of the output of the pump 36, means is provided for quickly and easily axially adjusting the valve member 130 along the shaft 42. This means comprises a rod 150 which is axially slidably disposed within a central bore 152 formed in the lower end of the shaft 42. A transverse pin 154 is connected with the upper end of the rod 150. Opposite ends of the pin 154 extend through axially elongated slot means 156 formed in the shaft 42 and into complementary apertures provided in the valve member 130 for connecting the valve member with the rod 150. Thus by axially adjusting the rod 150, axial adjustment of the valve member 130 is accomplished. The rod 150 rotates with the shaft 4-2 and therefore bearing means is provided at the lower end of the rod 150 to enable the rod to be connected with means for accomplishing adjustment thereof. This bearing means includes an inner race 158 fixed against axial movement relative to the rod by snap rings 160 and 162. An outer ball race 164 is suitably mounted within the ring 166. A bar 168 is pivotally connected to the ring 166 by a pin 170. In order to balance the forces involved, an identical bar, not shown, may be provided at the opposite side of the ring 166 from the bar 168 and pivotally connected thereto by a pin axially aligned with the pin 170. Additional pins 172 and 174 extend between and are secured to opposite ends of these bars. Stem means 176 which is welded or otherwise secured to the end plate 66 depends from the end plate at one side of the shaft 42 and has a horizontally elongated slot 178 adjacent its lower end for receiving the pin 1'72.

A flexible element 180 is connected with the pin 174 at the opposite ends of the bars from the pivot pin 172, which. flexible elements extends upwardly through passageways provided in the main body member 52, the cylindrical members 56 and 58 and the opposite end plates 64 and 66 of the pump 36. An upper end portion of the flexible element 189 is wrapped around a small drum 182, see FIG. 4, which drum is pinned or otherwise fixed to a shaft 184; The shaft is rotatably supported by a bushing 186 mounted in a suitable aperture provided in a wall of the frame means 32 of the apparatus. A hand knob 188 is fixed to an outer end portion of the shaft 184 to permit turning of the shaft and raising or lowering of the flexible element 180. A nut member 1% is threaded onto the outer end of the shaft in such a manner that the frame wall 32 and the bushing 186 are clamped between the pulley or drum 182 and the knob 188 with a force which provides sufficient frictional resistance to rotation of the shaft 184- to prevent accidental or unauthorized rotation of the shaft. It will be appreciated that upon rotation of the hand knob 188 in a direction which causes raising of the flexible element 180, the bar 168 will be raised so as to raise the rod 150 and thus the valve member 130. Upon opposite rotation of the hand knob 188, the bar 168 and thus the valve member 1313 are lowered. In order to insure lowering of the valve member when the hand knob 188 is turned in the appropriate direction, a spring 192 is compressed between the lower end of the shaft 42 and the bearing race 158. An indicator plate 191 may be secured to the frame for cooperating with the knob which may be calibrated for indicating to an operator the output for which the pump 36 has been adjusted.

It will be appreciated that during a pumping operation the bearing pressures between the mating surfaces of the pistons and the bearing blocks 128 and 122 and between the blocks and the cam elements 116 and 118 will be very high. In order to prevent undue wear of the mating bearing surfaces, the pistons and the bearing blocks are formed in a manner which insures lubrication of the surfaces after each pumping stroke of the pistons. More specifically, the pistons 78 and are respectively provided with relatively large passageways 194 and 196 which extend axially from the counterbores which receive opposite ends of the springs 128. The passageways 194 and 196 respectively merge with restricted orifices 198 and 200 which open centrally of the rounded ends of the pistons and communicate with enlarged passageways or chambers 202 and 204 in the bearing blocks 121) and 122. These last mentioned passageways or chambers merge with restricted orifices 206 and 208 formed centrally in the bearing blocks and 122, which orifices in turn communicate with relatively large diameter recesses or chambers 211i and 212 which open at the cam engaging ends of the bearing blocks.

During a pumping stroke of the pistons, the pistons are forced against the bearing blocks and the bearing blocks are in turn forced against the cam elements 116 and 118 with suflicient force to prevent fluid or oil from leaking between the mating surfaces of these elements. At the same time, fluid is forced under high pressure and in a slightly compressed state through the passageways and restricted orifices in the ends of the pistons into the chambers 202418 and 284-212. As long as the pumping pressure is maintained the fluid will remain trapped and in a compressed state in these chambers in the bearing blocks. When the pumping pressure is relieved by the opening of the outlet port 82, the forces clamping the pistons against the bearing blocks and the bearing blocks against the cam elements are also largely relieved. The fluid or oil under pressure and in a compressed state in the chambers in the bearing blocks tends to flow back toward the passageways 194 and 196 in the pistons but such flow is retarded by the restricted orifices 198 and 268 and 286 and 208. As a result of these restrictions to such reverse flow and of the fact that the pressure between. these various bearing surfaces is relieved, the fluid and the pressure in the chambers in the bearing blocks is forced out between the mating surfaces of the pistons and the hearing blocks and between the mating surfaces of the bearing blocks and the cam elements 116 and 118 so as to lubricate these surfaces. As will be understood, this lubricating action takes place at the end of each pumping stroke of the pistons so that constant lubrication of these mating surfaces is continuously insured.

While the preferred embodiment of the present invention has been shown and described herein, it is obvious that many structural details may be changed without departing from the spirit and scope of the appended claims.

The invention is claimed as follows:

1. A pump structure comprising a rotatable shaft, body means surrounding said shaft and providing a plurality axially spaced portions of said shaft at opposite ends of said body means and between said first and second bearing means for actuating said pump elements in opposition to each other so that thrust of said pump elements against said pair of actuating means is absorbed in said shaft, said body means having combined inlet and vent apertures communicating with said chambers between said pump elements, means providing outlets communicating with said chambers betweensaid pump elements, check valve means including annular seats and valve elements axially shiftable and engageable with said seats respectively connected with said outlet means for preventing reverse flow to the outlet means, a rotary valve member axially slidable on and rotatable with said shaft for cooperating with said combined inlet and vent apertures for controlling venting of said chambers and thereby controlling the pump output, and means connected with said valve member through said shaft for axially adjusting said valve member for varying the pump output.

2. A pump structure as defined in claim 1, wherein said opposing pump elements have hollow end portions, said 8 pump structure comprising compression springs disposed between said pump elements'and extending into said hollow end portions for biasing the pump elements away from each other.

3. A pump structure, as defined in claim 1, wherein said rotary valve member isdisposed and actuated for closing said inlet and vent ports when said pump elements have reached ends of their suction strokes andhave substantially zero velocity soas to obtain substantially shockless pumping action.

4. A pump structure,.as defined, in claim 1, wherein said pump elements have rounded opposite outer end surfaces, said opposing means having generally axially facing annular cam surfaces inclined at opposite acute angles with respect to the longitudinal axis of said shaft, said pump structure including a pair of bearing blocks respectively disposed between the rounded end surfaces of said pump elements and the adjacent cam surfaces, said bearing blocks having bearing surfaces complementary to said rounded surfaces and the cam surfaces, and aperture means extending generally axially'through said pump elements and said bearing blocks for directing fluid from the pump chamber to said bearing surfaces for lubricating purposes.

References (Iited in the file of this patent UNITED STATES PATENTS 1,697,853 Coursen Ian. 8, 1929 1,934,344 Coles Nov. 7, 1933 2,142,086 Alden Jan. 3, 1939 2,403,854 Geyer et al July 9, 1946 2,405,938 Beeh Aug. 20, 1946 2,492,688 Dall Dec. 27, 1949 2,573,792 Jakobsen Nov. 6, 1951 2,709,339 Edelman et al May 31, 1955 2,745,350 Capsek May 15, 1956 2,842,068 Sundin July 8, 1958 FOREIGN PATENTS 980,939 France May 21, .1951

OTHER REFERENCES German Application, S31175Ia/59a, May 17, 1956. German Application, K16993Ia/ 59a, Mar. 22, 1956.

Claims (1)

1. A PUMP STRUCTURE COMPRISING A ROTATABLE SHAFT, BODY MEANS SURROUNDING SAID SHAFT AND PROVIDING A PLURALITY OF PUMP CHAMBERS SPACED AROUND SAID SHAFT, SAID SHAFT EXTENDING THROUGH SAID BODY MEANS, FIRST AND SECOND BEARING MEANS ROTATABLY SUPPORTING SAID SHAFT AT OPPOSITE ENDS OF SAID BODY MEANS, A PLURALITY OF PAIRS OF OPPOSITELY DISPOSED RECIPROCABLE PUMP ELEMENTS RESPECTIVELY WITHIN SAID CHAMBERS, A PAIR OF OPPOSING MEANS CONNECTED WITH AXIALLY SPACED PORTIONS OF SAID SHAFT AT OPPOSITE ENDS OF SAID BODY MEANS AND BETWEEN SAID FIRST AND SECOND BEARING MEANS FOR ACTUATING SAID PUMP ELEMENTS IN OPPOSITION TO EACH OTHER SO THAT THRUST OF SAID PUMP ELEMENTS AGAINST SAID PAIR OF ACTUATING MEANS IS ABSORBED IN SAID SHAFT, SAID BODY MEANS HAVING COMBINED INLET AND VENT APERTURES COMMUNICATING WITH SAID CHAMBERS BETWEEN SAID PUMP ELEMENTS, MEANS PROVIDING OUTLETS COMMUNICATING WITH SAID CHAMBERS BETWEEN SAID PUMP ELEMENTS, CHECK VALVE MEANS INCLUDING ANNULAR SEATS AND VALVE ELEMENTS AXIALLY SHIFTABLE AND ENGAGEABLE WITH SAID SEATS RESPECTIVELY CONNECTED WITH SAID OUTLET MEANS FOR PREVENTING REVERSE FLOW TO THE OUTLET MEANS, A ROTARY VALVE MEMBER AXIALLY SLIDABLE ON AND ROATABLE WITH SAID SHAFT FOR COOPERATING WITH SAID COMBINED INLET AND VENT APERTURES FOR CONTROLLING VENTING OF SAID CHAMBERS AND THEREBY CONTROLLING THE PUMP OUTPUT, AND MEANS CONNECTED WITH SAID VALVE MEMBER THOUGH SAID SHAFT FOR AXIALLY ADJUSTING SAID VALVE MEMBER FOR VARYING THE PUMP OUTPUT.

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