US2765750A - Fluid pump or motor - Google Patents

Description

@CL 9, 1956 P. HARTMANN 2,765,750

FLUID PUMP 0R MOTOR Filed Maron 9. 1954 llllll' II| All; l

6/ WVU/TOR.- /Qy 62 By PHILIP HARTMANN /3 IUI IH ll'lm /4 I /4/ /3 AHORA/5% United States Patent lO FLUID PUMP R MOTOR Philip Hartmann, Racine, Wis., assignor to Hartmann Manufacturing Company, Racine, Wis., a corporation of Wisconsin Application March 9, 1954, Serial No. 414,959 1 Claim. (Cl. 1113-138) This invention pertains to a fluid pump or motor, and, more particularly, it pertains to a liuid pump or motor of the vane type.

In vane type pumps or motors there is generally provided a shaft with a concentric rotor having radially movable vanes or hinged pivotally movable bucket type vanes. There is also provided an eccentric bore within which the rotor and vanes are disposed. With this construction there is only one position in every complete revolution of the rotor when the vane is fully extended from the rotor to thereby present the maximum pressure surface of the vane to the driving fluid medium such as oil or water. This position is attained when the vane is extended from the rotor and into the eccentric bore at the point of eX- treme eccentricity. For a phase of approximately fortyve degrees of angularity prior to and forty-live degrees subsequent to this position, the vane is being respectively extended from the rotor and retracted into the rotor.

The vane extending action is generally effected by centrifugal force, or a spring, or a rod, or a ring, with the eccentric bore providing the limitation on the vane movement as the vane is always in contact with the bore during rotation of the rotor. The vane retracting action is effected by the eccentric bore as the degree of eccentricity decreases during the latter forty-tive degree phase of rotation.

It is an object of this invention to provide a vane type pump or motor which has a maximum pressure area of a vane exposed to the Huid driving medium for a substantial portion of the power or work phase of said pump or motor.

Another object of this invention is to provide a vane type pump or motor wherein the vanes do not move with respect to the rotor during the power phase of operation. Thus, the vanes are fully projected at the beginning of the power phase and remain projected to the end of the power or work phase. In this manner the vanes are not required to slide or pivot on the rotor at the time when the vanes are subjected to the pressure of the fluid medium.

Still another object is to provide a pump or motor which will produce a large torque at the beginning 0f operation.

An additional object is to provide a pump or motor which operates with a reduced amount of wear and friction thereby increasing the life and eiciency of the pump or motor which also then requires less maintenance and repair attention.

Another object is to provide a vane type pump or motor which has its maximum vane pressure area eX- posed throughout the power phase of operation with a positive means of maintaining the vane and thereby not relying upon centrifugal force.

Other objects and advantages of this invention will become apparent upon reading the following description in conjunction with the accompanying drawings, in which,

Fig. 1 is an end view of a pump or motor of a preferred embodiment of this invention with the cover plate and an inner end plate removed.

Fig. 2 is a sectional View taken on the rotated line 2-2 of Fig. l but with the said cover plate and the said inner end plate in position.

Fig. 3 is a fragmentary end View of the pump or motor of Fig. l but with the said inner end plate in position.

Similar reference numerals refer to similar parts throughout the three views.

Referring to Fig. l, there is shown an end View of a pump or motor with the end cover plate and the inner end plate removed to permit a clear view of the machine. Also, for the purpose of explaining certain actions of the machine, the parts of Figs. 1 and 2 are shown in a selected position.

The pump or motor consists of a housing 10 with a uid inlet opening 11 and a fluid outlet opening 12 on opposite sides of the housing and shown by dotted lines. It should be understood that the function of the openings 11 and 12 could be interchanged with respect to forming the inlet `and the outlet. The bottom of the housing 10 is preferably provided with anchoring bases 13 which contain bolt holes 14 for attaching the housing 10 in a stationary position.

The housing 10 includes a top portion 16 of a generally cylindrical shape wherein the working parts are contained. Thus, a cylindrical bore 17 is formed within the housing to extend therewithin to an end wall 18. A ring 19 is preferably provided to be positioned within the bore 17 with its outer diameter conforming to the diameter of the bore 17 while its inner surface or periphery 21 is of a special configuration which is described later. At this time it should be noted that this invention could be practiced without the inclusion of the ring 19 if the ring inner surface were made as an integral surface of the housing 10. However, for the well-known purposes of forming the ring configuration, and for employing a metal which is superior to that of the housing, the use of a separate ring is preferred.

Referring to Fig. 2, it will be seen that the ring 19 does not extend the entire length of the bore 17. Instead, it is preferred that a circular end plate 22 be positioned against the wall 18 while a second circular end plate 23 is positioned to be spaced therefrom. The plates 22l and 23 are non-rotatable and therefore maintain the position shown in Fig. 3. Together the end plates define the length of the working chamber while the ring 19 extends through this length to abut the opposed faces of the plates. As shown by dotted lines in Fig. 1, the ring 19 has ports 24 and 25 extending therethrough to respectively communicate the housing openings 11 and 12 with the inside of the ring.

Rotatably mounted within the housing 1() and concentric to the bore 17 is a shaft 28 which has a rotor 29 keyed thereto. The rotor is preferably of a length equal to that of the ring 19. Fig. 2 shows the shaft mounted in a concentric opening 31 in the end of the housing 10 with needle bearings 32 and ball bearings 33. In this manner the shaft is maintained in a concentric position and is also secured against axial movement by the ball bearings as a snap ring 34 abuts the side of the ball bearing race to maintain it in place. A cover plate 36 is preferably bolted to the end of the housing 10 to fluid tightly close the same. The opposite end of the housing 10 is enclosed by a circular cover plate 37 which contains a centrally located bore 38 wherein needle bearings 39 are disposed to'provide rotating ease for the shaft 28 which extends therethrough. The plate 37 has an inner periphery 41 which abuts the outer surface of the end plate 23 to retain the later against the ring 19 when the cover plate is bolted into position as shown in Fig. 2.

Also, it is preferred that the plate 37 contain about its periphery a liquid seal O-ring 42 to make the housing uidtight. A uid seal may also be provided about the bore 38 as well as the cover plate 36.

Referring again to Fig. 1, it will be seen that four slots 46 are provided in the rotor 29 to be radial therewithin and spaced ninety degrees apart on the rotor pe riphery. As shown in Fig. 2, the slots preferably extend the length of the rotor. Slideably disposed separately Within the slots are four vanes 47, 48, 49, and 50 which are free to move radially with respect to the rotor 29 as hereinafter described. A pair of preferably cylindrical rods 51 and 52 is located within the rotor at right angles to each other to separately abut the bases or the radially inner ends of the diametrically opposed vanes as shown. 1n this construction, the rods 51 and 52 are free to slide radially with respect to the rotor and the shaft as the rods pass through the shaft and the rotor as shown by the dotted lines in Fig. l. Also, Fig. 2 shows how the rods are offset with respect to each other to permit them to be diametrically positioned transversely through the shaft 28. An important feature of this construction is that the rods and the vanes are of a uniform respective length so that a constant dimension is maintained from an outer vane tip 53 of the vane 47 to theV outer tip 54 of the diametrically opposite vane 49 and that dimension is the same on both pairs of rods and their respective vanes.

Attention is again directed to the surface or periphery 21 of the ring 19 where the top segment is formed as an arc of a circle preferably spanning an angle of ninety degrees measured from the vane 47 clockwise to the vane 48. This top arc is concentric about the center of the shaft 28 and the rotor 29. Thus, a constant and uniform clearance exists from the top of the rotor 29 to the top of the surface 21 throughout the top ninety degree seg'-- ment. As shown in Fig. 1, the bottom ninety degree seg` ment of the surface 21 between the vane 49 and the vane 50 is also concentric with the shaft and rotor axis and of a radius of a length equal to that of the rotor. Therefore, the bottom arc is co-incident'with the bottom curva-V ture of the rotor. With this arrangement, there is provided a uniform and constant dimension between any two diametrically opposite points on the top-and the bottom arcs. The constant dimension provided is the same as that provided between the tips S3 and 54, respectively, of the vanes 47 and 49, and that dimension is alsoprovided between the tips of the vanes y48'and 50. The remaining left and right hand side ninety degreesegmentsof the periphery 21 are then formed as tangentially as possible with the ends of the adjacent top and bottom arcs to connect therebetween and form a continuously curved surface 21. These side segments are curved to also provide the same constantV dimension between any two diametrically opposite points on their curvature; In this terminology, diametrically opposite points are two points which lie on a straight line through the centerior axis of the shaft 28 and intersect the surface 21.

For the purpose of the following explantion, it is assumed that the machine shown is a motor and the passageV 11 is the inlet of a liquid driving medium such as oil. Then oil under pressure would exert its pressure onto the side of the vane 47. Since the vane 47, in the position shown, is extended from the rotor 29 to its maximum extent, the left side face of the vane, as viewed in Fig; l, is exposed to the oil pressure fora full ninety degree clockwise rotation of he rotor and vane to the Fig, l position of the vane 48. Of course this means that the exposed side area of the vane is always at'its maximumand the oil pressure acting on that area produces the maximum power. Also, the vane is not required to slide radially within its slot during the rotation oftherotor through the top ninety degree angle and vthere is then no power expendedfor that.

When the rotor rotates clockwise through an angle of ninety degrees to move the vane 47 to the position shown of the vane 48, the vane tip 53 continually remains against the surface 21 as the vane 49 correspondingly rotates to the position of the vane 50, andthe vane 49 and the rod 51 maintain the constant dimension explained in the foregoing. Then when the vane 48 rotates clockwise to the position of the vane 49, the vane is forced into the rotor slot by the surface 21 since the clearance decreases between the periphery 21 and the periphery of the rotor. in this action, the vane 48 forces axially on the rod 52 and extends the opposite vane from its slot. In this manner, the vanes are constantly maintained against the surface 21.

To further assist the vanesV in their radial movement in the slots, as shown in Fig. 3, the plates 22 and 23 are provided with two pairs of arcuate slots 55 and 56 and also 57 and 5S, which are located concentrically but at different radii to conform approximately and separately, one to the tips of the vanes and the other to the base of the rotor slots. Also, radially disposed along the inner faces of the plates to communicate the slots 55 and 56 are radial grooves or channels 59, while grooves 60 communicate the slots S7 and 58. Oil inlet pressure then gets into the slot 55 and is exerted in the rotor slot since the plate groove S9 communica-tes between the slots 55 and 56, and since the slot 56 connects with the rotor slot. Thus, the vane 50, in the rotor rotating ninety degrees clockwise to move the vane 50 from its original position to the position of the vane 47, has oil pressure at its base to avoid a suction there which would impede its radial movement. The opposite effect is obtained in connection with the plate slots 57 and 53. Here the pressure is removed from the base of the rotor slot and -thereby allows the vane 48 to be easily retracted radially during a ninety degree clockwise rotation of the rotor to the original position of the vane 49.

A groove 61 is preferably formed radially on the inside face of the plate 23 and it communicates between the shaft-,28 and an outlet opening 62 in the base of the housing 10. Oil or other uids can then flow out through the opening 62 if any fluid does get between the end of the rotor and the face of the plate 23. This arrangement minimizes the loss. of power Vdue to retarding forces created .by the uid medium.

While a speciiic embodiment of this invention has been shown and described, it would be obvious that changes could be made within the scope of the invention. One such changecould be altering the number of vanes from thefour shown. Of course, the provision of an odd number of vanes would not readily permit the use of diametrically disposed rods such as rods 51 and 52 but a ring could be mounted to maintain the vanes against the periphery 21 of the working chamber. The use of a ring could be in the manner shown in U. S. Patent No. 2,623,470 and, in thebore of the coniiguration described above, the outer periphery of the ring would be shaped andpositioned exactly like the surface 21. 1t is also obvious thattthe well-.known construction of compression coil springs located between the base of the rotor slots and the base of the vanes, could be employed to maintain the vanes outwardly. Therefore, in view of the foregoing statements, this invention should be limited only by the scopeof the appended claim.

I claim:

A uid pump or motor comprising a housing having a uid inlet opening on one side thereof and a fluid outlet opening on the other side thereof and with an intermediate bore therein in communication with said inlet opening and said voutlet opening, a shaft rotatably mounted in said housing, a circular rotor concentrically mounted on said shaft for rotation therewith and disposed in said bore and having four radial slots equally spaced around the circumference of said rotor, a vane slidably disposed in each of said slots, pins radially and slidably disposed through said shaft and said rotor for alignment with and abutting the radially inner edges cf said vane for limiting radially inward movement only of said vane, said housing bore being defined by an endless surface including a rst quarter circle segment uniformly spaced from the circumference of said rotor and including a second quarter circle segment co-incident with the circumference of said rotor and disposed diametrically opposite said first segment and with said rst segment disposed intermediate said ud inlet and said liuid outlet and defining the working chamber of said pump or motor, said housing bore being further defined by having the same dimension between all pairs of points lying on said surface and a straight line transverse through the axis of said shaft, a plate disposed within said bore and axially adjacent said rotor and having uid passages respectively communicting said inlet opening and said outlet opening with the radially inner ends of said slots in said rotor immediately before and after said slots are rotated past said working chamber but not when said slots are adjacent said Working chamber.

References Cited in the file of this patent UNITED STATES PATENTS 138,334 Lucas Apr. 29, 1873 6 Austin July 2, 1907 Beach et al Aug. 29, 1911 Killman Oct. 10, 1916 Rasmussen Jan. 7, 1919 Beidler et al Mar. 27, 1934 McCann Apr. 9, 1935 Garrison July 7, 1936 Mann Mar. 9, 1937 Curtis July 11, 1939 Heckert Mar. 5, 1940 Davis Oct. 28, 1941 Roessler Apr. 7, 1942 Brennan Mar. 28, 1944 Curtis July 4, 1944 Kendrick et al. Sept. 5, 1944 Hagstrom Sept. 12, 1944 Fanning Oct. 10, 1944 Rosen Jan. 15, 1946 Roth et al Oct. 10, 1950

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