US2375923A - Pump - Google Patents

Description

' lcgend= May 15, 1945. @.w. JOHNSON zvsgs" PUMP Filed Aug. 2, 1940 EIG.I

OTTO W. JOHNSON /VVENTR and Patented May 15, 1945 A' UNITED STATES PATENT oFncE PUMP i Otto William Johnson, Oakland, Calif. Application August 2, 1940,'seria1 No. 349,917

.7 Claims.

This invention is particularly concerned with the improvement of that type of pump disclosed in the United States patents to Holmes 2,049,775 issued August 4, 1936, to Kearney 1,678,049 and 1,678,050 issued July 24, 1928, and the patents to Dyer 639,541 issued December 19, 1899. The disclosures of these prior patents are referred to to furnish the basic explanations of the operation of this type of pump as understood prior hereto, as well as to indicate many of the problems recognized in the prior development of the art.

The major objectives of this invention are three-fold; including, the prevention of pump self-destruction by removal of any attempt on the part of the pump to compress uid at any time of its cycle, the substantial diminution of wear and friction losses, and the provision of a construction permitting efficient manufacture.

Subsidiary objects contributing to the diminution of wear and friction losses include; the reduction in frictional thrust bearing areas at vulnerable points; the diminution of unbalanced lateral and end thrusts as respects the axis of rotation, and the provision for automaticallyforced lubrication of vulnerable bearing areas.

In the drawing: l

Figure 1 is a side elevational view of a pump from which the port ducts have been cut away to show the valve port in relief as respects the interior surface of the housing or stator;

Figure 2 is a side elevational view of the pump rotor as it would appear if the housing were removed, and with the rotor parts in a position with one set of valve ports completely covered only at the instant when the rate of change of displacement space is zero;

Figure 3 is an edge-on view, half in mid-crosssection, of the displacement and end-thrust absorbing link; p

Figure 4 is a view from line 4-4 of Figure 3;

Figure is a section through the pump along the line 5-5 of Figure 1 with the rotor in the position of Figure 2.

an intake and discharge and drive shaft accommodatlng portion 4 serving as a. base for the pump and of a precessing shaft accommodating portion 6 providing complemental interior hemispherical surfaces 8 and I0 having valve ports' I I2, I4, and I2', I4', and bearing openings I6 and I8 for the drive and precessing shafts 20 and 22,

The shafts are inclined through the desired v I2' are reciprocal images with respect to the' common or precessing. plane including the drive and precess shaft axes, and numeral paired ports I 4, I4 are in like relation to said precessing shaft and'plane. Numerally paired ports coact in the sense of forming intake and discharge means for the pump, each pair accepting and delivering part of the volume of fluid ow, the ports being equal for purposes of balance for which reasons the ports are all of like proportions. Juxtaposed pairs of ports I2 and I4 coact in the sense of. eitherv delivering the entire ow or accepting the entire ow and juxtaposed pairs of ports I2' and I 4 perform the opposite function.

The ports of juxtaposed pairs, I2 and I4 for example, are symmetrically placed with respect to the median plane ofthe angles between shafts 20 and 22 and normal to the lprecessing plane thereof. Y In other words, all points on the spherical surface edge of a juxtaposed port find their image in its paired port at a point 180 degrees plus the angle inclination 4of the drive and precessing shaft, in the illustrated structure, approximately 200 degrees, or degrees, depending on the point and direction of angular departure, as referred to the axis of the spherical surface normal to the precessing plane.

These dispositions of the ports are disclosed explicitly in the Kearney patent except as hereinafter specified.

The rotor is formed of three principal portions in general conformity with the teachings of the prior art, utilizing the end members 24 and 26 having generally spherical sector contours and sphericalsurfaces with securement to the drive and precess shafts or integration therewith to cause coincidence of sector and shaft principal axes, as in all of the mentioned patent disclosures.

The intermediate member, or link 28, which,

The pump comprises a housing 2 formed of 55 together with the end members causes the displacement of fluid from one set of juxtaposed ports to the other, is provided with trunnions formingbearings for pins 36 and 32 whichtrunnions, in turn, bear in the end members as at 3l and over the outer-cylindrical surface of the end members adjacent trunnions 46. Pins 30 and 32 together with bolts 42 form a positive link holding the end members from displacement away from the link 28. 'I'he pins 30, 36 forming the bearing pivot pins in the intermediate member for the end member 26 have their axes in alignment and disposed to pass through the center of the spherical surface of the pump chamber, in conformity with the teaching in Figures 12 and 13 of the Dyer patent showing the axis of pivots to pass through the'center of the spherical surface. The pivotl pins 32 for anchoring end member 24 in the intermediate member are also disposed in member -28 to pass through the center of the spherical surface, but with their axes at right angles to the axes of pins 30. This construction requires that the pins have their axes of rotation lying in the same plane as shown, the axis of pins 30 lying at right angles to the axis of pins 32 in said plane, and said axis of pins 30 intersecting said axis of pins 32 at the center of the spherical surface. "I'he axis of pivots 30 necessarily lies at right angles to the axis of the precessing shaft 2i, and the axis of pivots 32 necessarily lies at right angles to the drive shaft 20. One construction providing for the pivotal interlinking of the two end members and the intermediate member is illustrated in the Dyer patent, and another in the Hurdle et al. Patent 389.927 issued Sept. 25, 1888.

In order to absorb the endwise thrust upon the end members 24 and 26, and to facilitate the construction so that proper sealing is insured between end and intermediate members, the intermediate member is provided with radial pin receiving wells 34 which wells are provided with cylindrical sector openings 36. The end members are provided with central radial ridge pieces 36 having laterally disposed projections 40 disposed through the sector openings 36.

'Ihe projections 40 are concave to iit the pins 30 and the end pieces are secured to the pins to rmly about these concave projections 40 by bolts 42 having their heads disposed in wells 44 formed/in the valve quadrants of the end members.

The Icentral portion 46 of the intermediate member is exteriorly cylindrical at one side concentric upon the pivots and the intermediate portion of the ridge pieces 38 is recessed with respect to the projections and cylindrically concave to tightly iit the central cylindrical portion 46 of the intermediate member. In this way the pins 30, for example, bear at their ends on the end trunnions 48 formed on the intermediate members, and on the interior bearing surfaces 60 of the cylindrical portion 46 to withstand expansive pressure tending to move the end members against the spherical surfaces of the housing and to diminish the friction and wear due to this tendency to expand. In addition, the portions 46 and 48 are of substantial strength and receive support from the central portion 52 of the interi mediate member so that there is no appreciable distortion at high speeds and pressures.

The wells 34 are otherwise continuously cylindrical, and opposite the trunnions 48 and 60, the sectors 64 may, as illustrated in Figure 5, form a continuous barrier between the ypin vanti the variable chambers 66.

By the construction and arrangement ofthe u parts of the roto Pins, and bearing and sealing surfaces in the ner described, large bearing pins may be used to give adequate strength without seriously interI is of minimum volume or. fully collapsed.

The three members of the rotor are assembled as indicated and the spherical surface is turned on all three while in assembled relation, the spherical surface being formed continuously around the peripheryy 66 of the intermediate member and over the ends of the trunion portions 48 and 64.

In order to decrease friction between the spherical surfaces of the end members and the housing, and to diminish the degree of unbalance from the high to the low pressure side which tends to force the shafts against the low pressure side of the bearings, the lateral spherical surfaces 62 of the end members are recessed as at 64 to provide uid receiving pockets, and which, with the spherical surface of the housing, always form a closed lateral thrust equalizing chamber.

The thrust equalizing chamber is placed in communication with displacement chamber 66 beneath the opposite lateral spherical surface, by a passage 66. In this manner, a. high duid pressure in the displacement chamber of the delivery side is directly communicated to the moving pocket 64 disposed in movement on the intake side of the pump to thereby tend to equalize, and actually to substantially diminish the effect of the high pressure thrust toward the low pressure side.

In addition, as soon as valving removes high pressure from the displacement chamber. this compensating thrust is removed from the particular equalizing chamber associated therewith, and the `pressure in said equalizing chamber reduces to that of the low pressure side.

Because of this fact, there is always a thrust due to fluid pressure tending to bring the end members against the central pivot pins from both vmeasure, decreases the requirements for bypasses to protect the pump as a positive displacement Pump.

In order to effectively prevent the battering eilect upon bearing surfaces, vibrations, and noise, and fatigue in the metals caused by failure of` prior devices to fully appreciate and overcome such effects. the construction here described provides for escape of duid from the displacement chamber at all times wheny the nuid is' placed under any pressure from thecollapsing This is accomplished by providing for the instantaneous change of valving at exactly the instant when the rate of change of volume of the displacement space communicating with such valves is zero. Further, this is accomplished by making the valve portion of the end members, illustrated in projection by crisscross hatching in Figure 2, of exactly the same dimension S in the direction of rotation of the end member, as the dimension S' -of the valve port. The spherical surface of the end member between planes normal to the paper in Figure 2 and equidistantly parallel to the axis of 22 is delimited by cutting the metal away along such planes, as at 68, to form cavities in the end member opening into the displacement chamber.

These cavities are preferably deeper than the `dimension r, extending to a depth r plus t, in

order to provide a large approach to the uncovered portion of the valve port at all times. The width of the valve ports, transverse to the direction of rotation is limited by the dimension 'r which is determined by the normal plane immediately beneath the centerwardmost rim of pockets 64 as indicated by the line u. In order to increase the transverse dimension r, the points 70 of the pockets in each end member must approach each other so that the pockets themselves will not rotate into registry with the ports. Valve registry with the ports occurs only when the rate of change of displacement space controlled by the valve is zero.

In order to further control the forces of heavy duty operation, circumferential bearing support for the intermediate member over a maximum area may be provided throughout its oscillatoryl movement by increasing the distance between the adjacent boundaries b of the valve portsto thereby increase the webs 12, Figure 5.

Reference is made to the claims for a definition of that for which protection is afforded hereby.

I claim:

1. In a pump having an internal generally spherically surfaced stator. or housing and a three member positive displacement rotor comprising externally spherically surfaced end members of equal curvature to, and disposed within,

the stator; means mounting said rotor for rotation within said housing; pockets in the spherical surfaces of said end members, and means for communicating high-pressure-side fluid to the pockets only when said pockets are disposed toward the low pressure side of the pump.

2. In a pump having an interiorly spherically surfaced housing and a three member positive displacement rotor comprising externally spherically surfaced end members of equal curvature to, and disposed within, the stator; means mounting said rotor for rotation in said housing; fluid receiving 4pockets between the spherical surfaces of the end members and the spherical surface of the housing; and means for communicating pump fluid pressures of the same intensity as are exerted by the pump on the discharge side of the pump to the pockets disposed at the intake side of the pump.

3, In a pump having a generally interiorly spherically surfaced housing and a positive displacement rotor of external spherical shape equal to the shape of said housing surface comprised of end members and an intermediate member disposed within said housing, means mounting said rotor for rotation within said housing, said intermediate member providing axially displaced and aligned pivot pins and pin bearing journals, a

ridge member having concave projections thereon adapted to fit said pivot pins formed within said end members and radially detachably secured to said aligned pin members to provide a iiuid tight fit, said intermediate member and said end members having contacting concentric cylindrical surfaces extending between the adjacent ends of aligned pin members and additional concentric contacting cylindrical surfaces adjacent to ends of the pin members to provide a fluid seal.

4. In a pump having an internally spherically surfaced housing and a positive displacement rotor of external spherical vshape equal to the shape of said housing surface comprised of end members disposed in said housing; means mounting said rotor for rotation in said housing, pockets disposed between said end members and said spherical surface of said stator housing and formed in said end members, and means for conducting iluid under pressure created by said rotor into the pockets only when the pockets are disposed away from the side of the rotor exposed to rotor created pressure.

5. In a pump having a generally interiorly spherically surfaced housing and a positive displacement rotor of spherical shape equal to the shape of said housing' surface, comprised of end members disposed within said housing; means mounting said rotor for rotation in said housing, pockets disposed between said end members and said spherical surface of said stator housing and formed in the end members, and means for conducting iluid to said pockets from the side of the pump diametrically opposite the pockets only when the said side of the pump is experiencing pressure created bythe pump.

6. In a pump having a generally spherical stator or housing and a three member positive displacement rotor comprising externally spherically surfaced end members and a spherically surfaced intermediate member and an interior spherical surface on said housing member fitting said rotor, the end members being fitted to said intermediate member for pivoting about spherical surface diameters at right angles to each other as respects the intermediate member, and the end members being so related to the intermediate member and the spherical interior surface of the housing and so mounted for rotation within the housing that two variable volume spaces are providedbetween each end member and the intermediate member and so that fluid cannot pass from one of said two spaces to the other of said two spaces, the end members rotating about axes intersecting in an obtuse angle at the center of said spherical surface; pockets in the spherical surfaces of said end members in the regions respectively lateral to the plane in; cluding their rotating axes and the axes of pivoting of the end members to the intermediate member, said pockets being closed at all times and positions of rotation by the spherical surface of said housing and adapted to contain a fluid for lubricating the contacting areas. of said housing and said end members, and means for conducting fluid from one of the two spaces adjacent one end member to the pocket adjacent the other space which is adjacent said one end member.

7. A construction according to claim 6, wherein the last named means includes means for conduction of the uid through said one end member. v

A OTTO WILLIAM JOHNSON.

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