US2878753A

US2878753A - Vane pump

Info

Publication number: US2878753A
Authority: US
Inventors: Cecil E Adams; William E Eschliman; Sun Yung Ho
Original assignee: American Brake Shoe Co
Current assignee: American Brake Shoe Co
Priority date: 1954-03-17
Filing date: 1954-03-17
Publication date: 1959-03-24
Anticipated expiration: 1976-03-24

Description

March 24, 1959 c. E. ADAMS ETAL VANE PUMP Filed March 17, 1954" 5 Sheets-Sheet 1 INVENTORS CECIL ADAMS YUNG HO SUN BY WILLIAM E.E$CHLIMAN MV/(fl March 24, 1959, c. E. ADAMS EI'AL 2,878,753

VANE PUMP Filed March 17, 1954 5 Sheets-Sheet 2 IN V ENTORS CEClL E. ADAMS I YUNG HO SUN M 4 Y WILLIAM E.ESCHLIMAN March 24, 1959 c. E. ADAMS ET AL 2,878,753

- VANEI PUMP Filed March 17, 1954 s Sheets-Sheet s INVENTO cscn. E. ADA BY Yum H0 sum WILLIAM E.ESGHLIMAN March 24, 1959 c. E. ADAMS VEITAL 2,878,753

VANE PUMP Filed March 17, 1954 s Sheets-sheet 4 I O- @56 r24 0 v 57 O O 0 G58 L r w CE. iflflfl i 64 BY waLuAm g z s -l AN ymzm March 24, 1959 c. E. ADAMS EI'AL' 2,878,753

VANE PUMP Filed March 17. 1954 5 Sheets-Sheet 5- IN NTOR CECIL DAM YUNG H0 SUN W. 8 BY WILLIAM E. ESOHLIMAN United States Patent VANE PUMP Cecil E. Adams, William E. Escll'liman, and Yung Ho Sun, Columbus, Ohio, assignors, by mesne assignments, to American BrakeShoe Company, New York, N.Y., a corporation of Delaware Application March 17, 1954, Serial No. 416,768

Claims. (Cl. 103-42) This invention relates generally to hydraulic apparatus andis directed to improvements in fluid pressure generating mechanisms of the type shown in the co-pending application Serial No. 363,098, filed June 22, 1953, by Cecil B. Adamsand William E. Eschliman.

An object of this invention is to provide a compact and practical fluid pumping mechanism having a pump and valve combination adapted to be driven by an internal combustion engine or other variable speed prime mover and designed to provide a constant flow of fluid irrespective of the speed of operation, within limits, of the prime mover, the operating power requirements being variable as the speed of operation changes and at no time being in excess of a predetermined economical maximum.

Another object of the invention is to provide a fluid pressure source having a combined pump and valve mechanism, the former including a plurality of pump sections each having a separate outlet, the latter operating to either combine the outputof the pumping-sections or to re-circulate the output of one or more of the sections to substantially maintain a predetermined volumetric output of the mechanism and limit the consumption of horsepower necessary to effect the operation of the device.

Another object of the invention is to provide a' combined pump and control mechanism in one casing, the latter including pumping and valve chambers and passages connecting portions of the chambers, pressure responsive'valve means being provided in the valve chamber to effect different combinations of connections be-' tween the passages whereby the entire output of: the pump will be directed to a delivery port or varying pro portions of the output of the pump may be directed tothe delivery port and the remainder re-circulated througlrthe pump.

Another object of the invention is to provide the mechanism set forth in the preceding paragraph with a novel valve combination having a spool urged inone direction by a resilient force and in the opposite direction by the-higher pressure of a pressure difierential created in one of the passages by fluid flow therethrough;

Another object of the invention is to provide a fluid pressure source having a combined pumping and valving mechanism, the pumping mechanism having a plurality of pumping sections with separate outlets and the'valving section having valve means responsive to fluid pressure to move from a position in-which the outputfrom all of the pumping, sections is directed to a common delivery portto various positions in which the output of one or more of the pumping sections is r e-circulated through'the pump, checkvalve means being provided to prevent the return or re-circulation of fluid from the sections connected by the valve mechanism withthe delivery port.

A still further object of the invention is to provide the valve mechanism mentioned in the preceding paragraph withflmeans' for forming a flow restricting orifice the Patented Mar. 24, 1 959 2 differential caused by the orifice, a portion of the valve element serving to conduct fluid from one side of the orifice-forming mechanism through a Zone containing fluid at the pressure of the other side of the orificeforming mechanism and applying such pressure tov a portion of the valve means to control its movement.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodiment of the invention J is clearly shown.

In the drawings:

Fig. 1 is a plan view of a hydraulic pumping mechanismformed in accordance with the present invention.

Fig. 2 is a longitudinal sectional view taken through he mechanism shown in Fig. 1 on the plane indicated by the line II-II ofFig. 1.

Fig. 3, is a similar view taken through the mechanism on the plane-indicated by the line III-IIIof Fig. 2.

Fig. 4 is a vertical transverse sectional view taken through the pumping portion of the mechanism on the plane indicated by the line IV-I V of Fig. 2. v

Fig. 5 is a similar, view on the plane indicated by the line VV of Fig. 2.

Figs. 6 and 7 are vertical transverse sectional views taken through the mechanism on the same plane by looking in the direction of the arrows VIVI" and VII-VII, respectively, of Fig. 2.

Fig. 8 is a diagrammatic view partly in section of the combination pumping and valving mechanism showing the connections betweenthe various pumping sections and ports in the valving mechanism.

Fig. 9 is a longitudinal sectional view taken through the valving mechanism showing the parts in' a different position of use than that shown in other figures.

Referring more particularly to the drawings, the numeral'20 designates the combination pumping and valving mechanism in its entirety. In the adaptation ofthe invention shown, this combination pumping and valving mechanism includes a casing or housing formed orfour main parts 21 to 24, inclusive. The

parts

21, 22"and 23 form the casingof the pump while the part '24.forms the casing for the valve mechanism.

Parts

21, 23 and 24 may be formed in any; suitable manner, such as by casting, and may be formed from any desirable. material, aluminum having been used in the construction of a satisfactorily operating device. Part 22, for reasons which will be apparent from the following description, v rnayfltie made of steel or other hardenable material.

The pump casing including the parts 21', 22" and 23 provides a rotor chamber 25 (see Figs. 4 and 8) whi ch is of generally circular formation but which has a plurality of lobes or zones designated by the numerals .'26 to 31, inclusive. The rotor chamber 25 is formedentirely in the section 22 of the casing and, casing, section 221 provides a generally annular wall: for the rotor chamber having arcuateportions at the lobes 26 to 31, inclusive, which areconcentric with the center offthe rotor chamber 25 but whichare spaced different distances from such center. These portions 26 to 31'are joined by other portions, hereinafter termed ramp s f which establish smooth surfaces connecting the. adjacent concentric. portions. The annular wall; of the rotor chamber 25 is ground and lapped to present a. smooth surface for engagement by vane elements 32 carrieduby a rotor 33 disposed forrotation in the rotonchamben characteristics of whic'h will'remainthe same eventhough 1 the valving element moves in response to the pressure Rotor 32 is supportedon a shaft .34njournaled in needle bearings 35 carried by the casing. or housing SCtlOl1Si21.

and23, these'casing or housing sections-being; formed with central. openings to receive.thebearingsu. Thersece tion 21 has the central opening extending completely through it to permit the one end of the shaft to project from the casing for attachment to a suitable prime mover such as an internal combustion engine or a motion transmitting mechanism operated thereby (not shown). While the central opening in the section 23 also extends completely through this section, it is closed at the outer end by the casing section 24. The escape of fluid from the section 21 around the shaft 34 is prevented by a shaft seal member 36 secured in the section 21 adjacent the outer end of the central opening. Between the seal 36 and the bearing 35, the casing section 21 is formed with an annular groove 37 to collect fluid seeping past a second seal 38 arranged in the central opening of section 21 at the outer end of the bearing 35. A similar seal 38 is provided at the outer end of bearing 35 in the casing section 23. The purpose of these seals will be apparent from the following description.

Casing section

21 and 23 are formed to include a plurality of ports registering with the ramps between the lobes or zones 26 to 31, these zones and adjacent ramps forming a plurality of pumping sections. One of the ports, designated by the numeral 40, constitutes an inlet port and serves to admit fluid to the rotor chamber 25. The ramp registering with this port slopes in a direction to permit the vanes 32 moving across the same to move in an outward direction in the rotor 33 and thus increase the volumetric capacity of the fluid transfer pockets between the vanes 32. In operation, the rotor turns in the direction of the arrow shown in Figs. 4 and 8. It will be noted from Figs. 4 and 8 that the vanes 32 employed in the pump include a pair of spaced sealing edges for engagement with the annular wall of the rotor chamber 25. Similar spaced edges are formed on the ends of the vanes 32 to engage the side walls of the rotor chamber 25 formed by the adjacent end surfaces of the

casing sections

21 and 23. In addition to providing spaced seals, the sealing edges also provide passages which establish communication between the inner ends of the slots in the rotor and the space between the sealing edges at the outer end of the vanes 32 where they contact the annular wall of the rotor chamber 25. This arrangement establishes equal fluid pressures at the inner and outer ends of the vanes so that no hydraulic pressure will be exerted upon these ends to move the vanes inwardly or outwardly. Piston pins 41 are provided in the rotor 33 to urge the vanes 32 in an outward direction under a predetermined force, the manner of application of fluid pressure to the pistons 41 being set forth hereinafter. As

the rotor 33 revolves in the direction of the arrow shown in Figs. 4 and 8, the vanes 32 will move across the concentric portion of the annular wall at lobe 26. Both edges of each vane 32 will engage the annular wall and establish a double seal between the fluid transfer pockets at opposite sides of the vane. As the vanes 32 traverse the first ramp after leaving lobe 26, they will be forced inwardly into the rotor a predetermined distance and some of the fluid in the transfer pocket immediately preceding the vane will be expelled through a port 42 of

grooves

47, 48 and 49 through 51 are disposed on opposite sides of a groove 53 and the latter is connected by a conduit or passageway 54 (see Fig. 8) with the inlet port 40.

It will be noted from Figs. 2 and 3 that complemental ports are provided at opposite sides of the rotor to permit rapid flow of fluid to and from the fluid transfer pockets formed by the rotor, vanes and casing walls. Two of these complemental ports are identified by the numeral 39 in Fig. 3 of the drawings.

In the diagrammatic view shown in Fig. 8, the inlet and outlet ports of the pump are connected with the respective grooves in the valve casing. As illustrated, groove 53 is connected by conduit or passageway 54 with inlet port 40. Outlet ports 42 to 46, inclusive, are connected with grooves 47 to 51, respectively, by conduits or

passageways

55, 56, 57, 58 and 59, respectively. Grooves 47 to 51, inclusive, are also connected by a manifold, indicated by the numeral 60, with a common fluid delivery port 64, the manifold 60 being disclosed in Fig. 6 as a recess formed in that end of casing section 23 which abuts casing section 24. As indicated in Fig. 8, check valves 62 are disposed between the

grooves

47, 48, 49 and 50 and the manifold 60 to prevent fluid flow from the manifold 60 to said grooves. These check valves may be of any form, spring-pressed balls 63 (see Fig. 6) being shown in the form of the invention illustrated. It will be noted that no check valve is necessary between groove 51 and the manifold 60, the latter groove being open to a central opening 64 formed in a fitting 65, the opening 64 constituting the common pressure fluid delivery port mentioned above. The fitting 65 is internally threaded to connect port 64 with a conductor leading to the point of use of the fluid.

Fitting 65 is also provided with a disk 67 having a central opening through which fluid may flow from groove 51 to the delivery port 64. Disk 67 cooperates with a projection or stem 68 formed on the end of a valve spool 70 to form a ring-like or annular orifice; the valve spool 70 is disposed for sliding movement in a linear 71 arranged in the bore 52. This liner provides a smooth surface for the slidable reception of the valve spool, the liner being formed with one or more sets of ports establishing communication between the grooves 47 to 51, inclusive, and 53 and the interior of the liner. The spool 70 has a plurality of annular grooves 72 to 75, inclusive, spaced longitudinally thereof, these grooves serving to establish communication between certain sets of grooves formed in the casing section 24 in different longitudinal positions of the spool.

In the position shown in Fig. 2, spool 70 prevents communication between any of the annular grooves 47 through 51 in the section 24. In this position of the spool 70, all of the fluid expelled from the outlet ports registering with such ramp. Port 42 constitutes the outlet for the first pumping section. Subsequent outlets are designated by the

numerals

43, 44, 45 and 46. It will be noted that the ramps registering with these outlets are all inclined in such a manner as to cause the vanes to move into the rotor and fluid to be expelled through the outlet ports. It will be noted also that all of the fluid is drawn into the pockets between the vanes 32 through the single inlet port 40 and that a predetermined portion of this fluid is expelled through each of the outlet ports 42 to 46.

These inlet and outlet ports are connected by passages formed in

casing sections

23 and 24 with annular grooves spaced longitudinally of a bore formed in the casing section 24.

Grooves

47 and 48 are disposed adjacent one end of the bore 52 while grooves 49,. 50 and 51 are disposed adjacent the opposite end of the bore. These groups 42 to 46, inclusive (Fig. 8), is directed through the manifold 60 to the annular groove 51. Pressure in the groove 51 causes the spool 70 to lift slightly from the disk 67 whereby fluid may pass into the delivery port 64. The spool 70 is urged toward the position shown by coil spring 76 arranged in the spool and in a socket formed in a cap 77 closing the open upper end of the bore 52. This cap serves a dual purpose in that it also clamps the liner 71 in place. When the fluid flows from the outlet ports 42 through 46 of the pumping sections to the grooves in the valve casing and from these grooves through the manifold 60 to the delivery port 64, it must flow through the annular orifice formed by the aperture in the disk 67 and around the projection 68 on the spool. This orifice restricts the flow of fluid causing a pressure differential to exist at opposite sides thereof. The higher pressure or the pressure at the inlet side of the orifice and in groove 51 is applied directly to the spool to move it in opposition to the force of the spring 76. This valve functions in the nature of a flow control, the pressure at the outlet side of the orifice and in the port 64 being vapplied through a central passage 69 in the extension 68 to the hollow interior to the valve spool 70 to assist the spring 76 in opposing the movement of the spool. The force of the spring and the assisting lowered pressure .within the spool 70 balance the force at the inlet side of the orifice causing the spool to assume a position of equilibrium. If more fluid is expelled from the pump due to an increase in the rate of operation, the pressure at the inlet side of the orifice will tend to increase causing the spool to move in opposition to the spring. After the spool 70 moves a predetermined distance, groove 72 therein will establish communication between groove 47 in the valve casing and groove 53 and some of the fluid expelled through the outlet port 42 will then be bypassed through conduit 54 back to the inlet 40 of the pump rather than being directed to the delivery port 64. If the rate of operation of the prime mover (not shown) is further increased and the volume of fluid expelled from the pumping mechanism continues to increase, valve spool 70 will continue to move increasing the degree of communication between groove 47 and groove 53 until the entire output of outlet port 42 is being by-passed back to inlet port 40. At this time, the horsepower necessary to eflect the operation of the first section of the pumping mechanism will be decreased to only that necessary to overcome the friction inasmuch as the pressure in that pumping section will be substantially completely relieved. Should the volume of fluid expelled from the pumping mechanism continue to increase, spool 70 move further until groove 48 will become connected with groove 47 and consequently also with groove 53 and part of the output to groove 47 will be directed to the inlet port 40 of the pump. This movement of spool 70 will continue as long as the volume of fluid pumped increases thereby causing groove 74 in the spool to place groove 49 in communication with groove 53 and finally to place groove 50, through groove 75 in spool 70, in communication with

grooves

49 and 53 whereupon all or most of the fluid being discharged from the output ports 42 through 46 will be returned through conduit 54 to inlet port 40. If the rate of operation of the prime mover is reduced and the volume of fluid pumped decreased, the balance in forces at opposite ends of the spool 70 will be destroyed and spring 76 will tend to move the spool to direct more fluid to the delivery port 64 and thus restore the balance. It will be obvious that spool 70 will float in the sleeve 71 to increase or decrease the volume of fluid re-circulated and thus maintain the output through the delivery port 64 substantially constant.

As shown in Figs. 6 and 7, conduit or passageway 54 includes a recess 78 formed in the end wall of section 23 and an opening 79 formed in casing section 24, the opening 79 leading to and communicating with the groove 53. As shown in Fig. 3, an inlet pipe 81 leading from a reservoir 82 communicates with the conduit or passageway 79 and groove 53. Fluid from the reservoir 82 will flow through pipe 81 to the conduit or passageway 79 froming part of conduit or passageway 54 and to the inlet port 40. Fluid by-passed by the valve spool from grooves 47 to 51, inclusive, to the groove 53 will also flow through opening 79 and passage 54 to the port 40. The end wall of casing section 23 is also provided with a plurality of openings and recesses which register with openings formed in casing section 24 to form the passages 55 to 59, inclusive, passage 59 coinciding with the lower end of the manifold 60.

As illustrated in Fig. 5, the end surface of casing section 21 which forms one end wall of the rotor chamber 25, is provided with recesses 83 to 88, inclusive, these recesses being disposed in radial registration with

outlets

40, 42, 43, 44, 45 and 46, respectively. The recesses 83 to 88 also register with the inner ends of the vane slots and, as the rotor revolves, fluid pressure is applied to the respective recesses from the complemental outlets through grooves formed in the end wall of the rotor chamber.

This arrangement insures the equalization of pressure at the inner and outer ends of the vanes as they move through the various pumping sections. A groove 90 extends from the recess 88 to the central opening in the

sections

21 and 23 and conducts fluid at the pressure in outlet 46 to this central opening. This fluid is applied through a groove 91 formed in the rotor to an annular groove 92 formed therein, this groove conducting the fluid to the inner ends of the piston pins 41. This feature of the invention has been disclosed andclaimed in the copending application Serial No, 406,127,,filed January 26, 1954, in the name of Cecil E. Adams and Yung Ho Sun. No claim to this feature is made herein. Fluid supplied through groove 96 is also applied to the needle bearings 35 to effect their lubrication and such fluid is confined to the spaces occupied by the needle bearings 35 by the shaft 34 and by the sealing members 38 previously mentioned.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

We claim:

l. Hydraulic apparatus including a plurality of casing sections assembled to form a rotor chamber having means forming an inlet port and a plurality of outlet ports spaced circumferentially thereof one of said sections forming an annular wall having a plurality of portions concentric with a predetermined axis in said chamber and spaced diiferent distances from" this axis, adjacent portions being connected by ramp portions registering with said inlet and outlet ports, the concentricportion spaced the greatest distance from said axis being disposed between the inlet port and an adjacent outlet port; a vane carrying rotor journalled for rotation in said rotor chamber to draw fluid in through the inlet port and expel it from said outlet ports; one of said sections forming a valve chamber with a plurality of ports spaced therein and a fluid delivery port, certain of said casing sections forming passages connecting said inlet and outlet ports with certain ports spaced in said valve chamber and certain of the latter ports with said delivery port; means between said valve chamber and said delivery port forming an orifice to create a pressure diiferential on fluid flowing to such delivery port; valve means disposed for movement in said valve chamber in response to said pressure differential to connect certain outlet ports with said inlet port to re-circulate the fluid issuing from such outlet ports, and means on saidvalve means exposed to the pressures at opposite sides of said orifice for operating said valve means in response to said pressure diiferential.

2. Hydraulic apparatus including a plurality of casing sections assembled to form a rotor chamber having means forming an inlet port and a plurality of outlet ports spaced circumferentially thereof, one of said sections forming a peripheral wall having a plurality of portions concentric with a predetermined axis in said chamber and spaced different distances from said axis, adjacent portions being connected by ramp portions registering with said inlet and outlet ports, the concentric portion spaced the greatest distance from said axis being disposed between the inlet port and an adjacent outlet port; a vane carrying rotor journalled for rotation in said rotor chamber to draw fluid in through the inlet port and expel it from said outlet ports; one of said sections forming a valve chamber with a number of ports spaced longitudinally thereof, the number of ports in said valve chamber being equal to the number of ports in said rotor chamber, certain of said casing sections forming passages establishing communication between each rotor chamber port and a different port in said valve chamber, said casings forming a manifold and a fluid delivery port connected therewith; means in said manifold in advance of said delivery port forming an orifice to resist fluid flow and cause a pressure difierential; valve means disposed for movement in said valve chamber to connect certain of the ports therein; spring means tending to urge said valve means toward a position to connect all of said outlet ports with said manifold, and means on said valve means exposed to the pressures at opposite sides of said orifice for moving said valve means to other positions to connect said outlet ports with said inlet port.

3. Hydraulic apparatus including a plurality of easing sections assembled to form a rotor chamber having means forming an inlet port and a plurality of outlet ports spaced circumferentially thereof, one of said sections 'forming a peripheral wall having a plurality of portions concentric with a predetermined axis in said chamber and spaced different distances from said axis, adjacent portions being connected by ramp portions registering with said inlet and outlet ports, the concentric portion spaced the greatest distance from said axis being disposed between the inlet port and an adjacent outlet port; a vane carrying rotor journalled for rotation in said rotor chamber to draw fluid in through the inlet port and expel it from said outlet ports; one of said sections forming a valve chamber with a number of ports spaced longitudinally thereof, the number of ports in said valve chamber being equal to the number of ports in said rotor chamber, certain of said casing sections forming passages establishing communication between each rotor chamber port and a diflerent port in said valve chamber, said casings forming a manifold and a fluid delivery port connected therewith; check valve means in said manifold to preventfluid flow therefrom to said valve chameach side of said resistor means, said piston being exposed at one end to the higher of said two pressures; means on said piston forming a passageway for iconnecting the other end of said piston with the lower of j said pressures whereby said piston is rendered responsive to said pressures to move in said bore to disconnect progressively the passage means leading from said separate outlet means from the passage means leading to said delivery port means and to connect the same progressively to the passage means leading to said inlet means.

5. Hydraulic apparatus including a pump having a casing, said pump including means forming an inlet and a plurality of pumping sections with separate outlet -means; means in said casing forming a fluid delivery port through which fluid is delivered from saidapparatus;

means in said casing forming a passage leading to said -delivery port means; fluid pressure responsive valve means including means forming a bore, a spool, in said bore normally cooperating to connect all the passage piston being exposed at one end to the higher of said 'two pressures; means on said piston forming a passageway for connecting the other end of said piston with the lower of said pressures whereby said piston is rendered responsive to said pressures to move in said bore to disconnect progressively the passage means leading from valve means toward a position to connect all of said 'means in said casing forming a passage leading to said delivery port means; passage forming means in said casing extending to said inlet means and from said outlet means; fluid pressure responsive valve means including means forming a bore, a spool in said bore normally cooperating to connect all the passage means leading from said separate outlet means with the passage means leading to said fluid delivery port means; resistor means at one end of said spool and in said passage means leading to said fluid delivery port means to resist fluid flow said separate outlet means from the passage means leading to said delivery port means.

References Cited in the file of this patent UNITED STATES PATENTS 2,074,618 Roeder Mar. 23, 1937 2,129,960 Presby Sept; 13, 1938 2,247,261 Towler et al. June 24, 1941 2,562,615 Huber July 31, 1951 2,568,356 Moulden Sept. 18, 1951 2,600,632 French June 17, 1952 2,611,245 Strehlow Sept. 23, 1952 r 2,611,319 Strehlow et al. Sept. 23, 1952 2,618,932 Taup Nov. 25, 1952 2,696,788 Funston Dec. 14, 1954 2,746,392 Klessig et al. May 22, 1956 2,747,598 Wooldridge May 29, 1956 2,752,853 Eames July 3, 1956 2,759,423 Keel Aug. 21, 1956 FOREIGN PATENTS 420,501 Great Britain Dec. 3, 1934 767,417 Germany Aug. 7, 1952 therethrough thereby to create two pressures, one on