US2371081A

US2371081A - Vane pump

Info

Publication number: US2371081A
Application number: US423338A
Authority: US
Inventors: Warren R Tucker; George A Waldle
Original assignee: Hydraulic Development Corp Inc
Current assignee: Hydraulic Development Corp Inc
Priority date: 1941-02-06
Filing date: 1941-12-17
Publication date: 1945-03-06
Anticipated expiration: 1962-03-06

Description

Mrch e, 1945. CKE ETAL 2,371,081

VANE PUMP ori inal Filed Feb. 6, 1941 2 sheets-sheet 1 INVENTORS By WARREN R TUCKER k scones A.WALD|E ATTORNEYS Mafch s, 1945.

W. R. TUCKER ET AL h S y t e e Penman". e, 1945 vans rum Warren R. Tucker and George A. Waldie, Dayton, Ohio, assignors to The Hydraulic Development Corp. Inc., W tion of Delaware 11, Del., a corpora- Original application February 6, 1941, Serial No.

Divided and this application Decent "T ber 17, 1941. Serial No. 423,338 1 Claim. (01. 103-138) This invention relates to fluid pumps 01' the vane type, and more particularly to fluid pumps which are adapted for circulating liquids and for producing pressure with said liquids for actuating various operating elements.

In this invention the fluid pump is adapted to pump hydraulic fluid from a storage chamber to a hydraulically actuated device, such as a press,

molding machine or other conventional hydraulically actuated mechanisms. There are many types of pumps which are adapted for placing fluids under pressure, but the types of pumps which have heretofore been used in placing liquid under pressure have been limited to the radial piston type of liquid pump. This type of pump produces high pressure with relatively low power consumption and has been the most efllcient type for use in producing high fluid pressures for actuating mechanical presses requiring high fluid pressures.

In this invention, however, mechanical alterations have been made to a vane type of fluid pump which makes it adaptable for producing high fluid pressures, and particularly, high liquid pressures which are of sufllcient value that the pump can be used as the pressure supply mechanism for actuating hydraulic mechanisms. In former vane type pumps considerable difficulty has been encountered in producing high pres-' sures, since the liquid slip past the vane has been considerable. There have been attempts to secure the vanes in constant engagement with the cylindrical wall of the cylinder and to increase the volumetric efficiency of vane type Dumps when used for liquid delivery. These applicants have produced a mechanism which promotes the maximum efliciency of a vane type liquid delivery pump and which retains the vanes of the pump in constant engagement with the cylindrical wall of the cylinder to prevent liquid slip past the endsof the vanes which are in engagement with the cylinder wall.

It is an object of this invention to provide an improved pump structure for use as a liquid It is another object of the invention to provide means for retaining the vanes ofa vane type pump in engagement with the cylindrical wall of the cylinder.

It is another object of the invention to provide 'a mechanism in accordance with the foregoing object whichresiliently urges the vanes outwardly into engagement with the cylindrical wall.

It' is another object of the invention to retain thevanes of a vane type pump in engagement with the cylinder wall by means of fluid or liquid under pressure. X

It is another object of the invention iio provide a vane type liquiddelivery pump having means for retaining the vanes in constant engagement with the walls of the cylinder, and which cylinder is adapted to be moved with respect to the pump rotor in order'to change the direction of delivery of the pump.

It is another object of the invention to provide a variable delivery reversible flow liquid pump of the vane type having a mechanism ior maintaining the vanes in engagement. with the cylinder wall, and which is constructed and arranged for movement of the cylinder with respect to the rotor without effecting the mechanism for maintaining the vanes in constant engagement with the cylindrical wall of the cylinder.

It is another object of the invention to provide .a variable delivery reversible flow fluid pump with means for conducting fluid under pressure under the vanes to force the same outwardly into engagement'with the cylinder walls, wherein means are pr'ovided for changing the flow of pressure fluid in the conducting means when the flow oi fluid through the pump is reversed.

It is another object of the invention to provide a; vane type fluid pump wherein the vanes are a loose fit within cooperating slots in the rotor to permit fluid to enter the slots which, when under pressure, will force the vane outwardlymentioned object wherein the vane can tilt an-,

gularly in either direction with respect to the slot and the sealbetween. the high and low pressure sides will be eflfective in either position of the vane. Y

It is another object of the invention to providev a variable delivery reversible flow fluid pump of. v the vane type having vanes which are a loose flt in the rotor slots for the same, and which has the advantages aforementioned for this type pump. It is another object of the invention to provide a vane type pump for liquid delivery which has Y a straight-through liquid flow through the pump. Further objects and advantages will become apparent from the description and the drawings.

In the drawings: Figure 1 is a longitudinal cross-sectional view I of the pump of this invention.

Figure 2 is a transverse cross-sectional view of a portion of the pumping mechanism showing a modified arrangement of pumping mechanism. Figure 3 is a perspective elevational view of one of the vanes used in the pump of Figure 2.

In this invention the fluid or liquid pump consists of. a casing having passageways l l and I2 extending therethrough. A substantially rectangular member 11 forms a cylinder block within which there is provided a cylindrical bore 18 which extends transversely of the block l1. This bore 18 forms the cylinder wallof the cylinder of the pump. The cylinder block 11 is carried between parallel faces I9 and 20 provided on the casing It, the parallel faces provided on the cylinder block 11 slidably engaging the faces l9 and 20 to permit the cylinder block H to be reciprocated thereon. A passageway 2| provided in the cylinder block l1 communicates with the passageway II, and a passageway 22 provided diametrically opposite thepassageway 2| communicates with the passageway I2.

A rotor member 23 has a body portion 24 pcsitioned within the cylinder bore l8. One side of the body portion 24 carries a flanged portion 25 which engages the wall of the cylinder block IT, as indicated at 28. An end plate 21-is secured to the rotor body 24 by means of the bolts V 28 and is adapted to engage the opposite face of the cylinder block 11, as indicated at 29.

The flanged portion 25 of the rotor 23 has a hub 30 extending therefrom which is carried by the inner. race 3| of a ball bearing 32 which is positioned within a recess provided in the casing 10. The end plate 21 has a hub 34 which carries a bushing 35. The bushing 35 is carried by the inner race 33 of a ball bearing 31 mounted within a recess 39 of the end plate 40 of the casing 10. The end plate 40 is secured to the casing ill by means of the bolts 41 and encloses the pumping mechanism within the casing in. The hub 30, on the flanged portion 25, extends outwardly of the casing 10 and provides a drive shaft 42 which can be suitably connected to a driving mechanism, such as an electric motor or any other suitable power device.

A conventional oil seal 43 is positioned around the drive shaft 42 and is retained within a recess 44 in the casing ill by means of a closure plate The body 24 of the rotor 23 is provided with a plurality of radial slots 46 in each of which there is positioned a vane 41. The vanes 41 have their outward ends in engagement with the cylindrical bore l8 and which cooperate with the cylindrical bore l3 and the body of the rotor 24 to provide means for pumping fluid between the passageways and I2. The vanes 41 have their inner readily be seen that the vanes 41 will extend into the bore 43 in the rotor body 24, and that the extending portion of eachvane will have a different length according to the position of the vane with respect to the eccentric positioning of the cylinder bore l8 with respect to the rotor body 24.

In order to retain the vanes 41, in constant engagement with the cylinder bore It a frustoconical pin 501s positioned within the bore 48 and is of such diameter that the surface thereof engages a complementary surface on each .of the inner ends of the vanes 41. Since the vanes 41 are all of equal length it can be seen that the pin 50 will be arranged concentric with respect to the cylindrical bore l8, and since the end surfaces 5| of the vanes 41 have'a form complementary to that of pin 50, it can readily be seen that the vanes 41 will remain in constant engagement with the cylindrical bore l8 at all points throughouttheir rotation about the pin 50. The pin 50 thus becomes a member which is floated by the inner ends of the vanes 41, which provides a rigid bearing surface upon which the vanes ride in order to mechanically urge the same into constant engagement with the cylindrical bore l8.

These complementary frusto-conical surfaces on the pin 50 and the vanes 41 cooperate, as indicated at 52, to provide surfaces by which the radial position of the vanes 41 can be altered. Longitudinal or axial movement of the pin 50 forces the vanes 41 outwardly to the right as seen in Figure 1 to thereby decrease the clearance between the end of the vanes 41 and the cylinder bore I8.

The adjusting means for axially or longitudinally moving the pin 50 consists of a cylindrical plunger 53 mounted within a bore 54 provided in the hub 30 of the rotor 23. The plunger 53 extends into the bore 49 within the body 24 of the rotor and engages the pin 50, as indicated at 55. A compression spring 58 is positioned between the end wall 51 of the

plunger

53 and 45 the end wall 58 of the bore 54, which spring tends ends extending within a central bore 48 provided in the rotor body 24. Thebore 43 extends into the flanged portion 25 and a cooperating bore 49 is provided in the plate 21. The vanes 41 are all of equal length and since the cylinder' bore I3 is eccentric with respect to the rotor. body 24 when the pump is in operating position, it can to urge the tapered pin 50 to the right, as indicated in Figure 1. The taper on the pin 50 extends from the left to the right thereof, viewed in Figure 1, so that movement of the pin 50 to the right will tend to force the vanes 41 outwardly into engagement with the cylinder bore 7 13. The spring 56 thus provides means for resiliently urging the tapered pin 50 into pressure engagement with the vanes 41. A small hole 53a is provided in the end of the plunger 53 to prevent the plunger from acting as a piston.

An adjusting screw is provided in the end plate 21 and engages a friction button 60 which en-.

gages the righthand end of the tapered pin 5|). The adjusting screw 59 is in threaded engagement within the hub 34 of the end plate 21. An inspection plate BI is provided on'the end plate 40 of the casing III to permit access to the adjusting screw 59. Means for binding the adjusting screw in position after an adjustment has been made is provided on the hub 34 of the end plate 21 and consists of a portion 62 of the hub which has been separated from the main body thereof by means of a slot 63. A screw 64 extends through the portion 62 and into threaded engagement with the body of the hub 34. When the screw 64 is tightened the flanged portion 62 will bind upon the threads of the adjusting screw 59 to retain the same in its properly adjusted position. A drain opening 96 is provided in the casing I to remove liquid or fluid leaking into the casing from the pumping mechanism.

The mechanism just described provides a fluid or liquid pump wherein the fluid flow through the pump is an in-line flow, whereby minimum resistance to fluid flow is obtained and which provides a structural arrangement whereby the .r intle.

' The pump can be operated as a variable delivery pump, or the fluid flow therethrough can be reversed. As previously described the cylinder block I! is in sliding engagement with the surfaces I0 and of the casing II. The plane of eccentricity of the cylinder bore I0 with respect to the rotor 23 is parallel to these surfaces I0 and 20 so that reciprocation of the cylinder block I! parallel to the surfaces I0 and 20 alters the eccentricity of the cylinder bore II with respect to the body 24 of the rotor.

In Figure 2 there is disclosed a modified form of pump rotor which can be used in the pump previously described. When used in the pump described with regard to 'Figure 1, the only modiflcation required of this pump is the removal of the tapered pin and the operating mechanism for the same.

This modified form of rotor consists of a rotor body 90 which is positioned within a cylinder bore 90 provided in a cylinder block 01. Suitable end plates are provided on the rotor 00 for sealing the ends of the bore 90 and thereby providing a pumping chamber. The structure of these end plates has been previously described and the specific manner of mounting the same in the pump casing has also been described so that the pumping mechanism in this modified .form contains the same advantages of minimum of friction developed between the working parts. Suitable bolts 98 extend through the rotor and secure the end plates thereto. I

A plurality of slots 90 extend longitudinally of the rotor 85 and also extend radially thereof. Vanes I 00 are adapted to be positioned within the slots 98 for reciprocation therein. It is of course understood that when the pump is in operating position the cylinder'bore 90 is eccentric with respect to the rotor 95, which rotor rotates concentric with respect to the bearing supportfor the same. It is also understood that the cylinder bore 90 is shiftable with respect to the rotor 00 to vary the flow of the pump or to reverse the flow thereof.

The vanes I00 have a cross-sectional dimension which is less in thickness than the width of the slot in which the vane is to operate, thereby providing clearance between the face surface I0l of the vane and the face surfaces I02 oi the slot. The faces -l0l of the vanes I00 are provided with an undercut portion toward the lower edge thereof which is angularly disposed with respect to the faces I0-I so that an angular face I0! i provided near the central portion of the lower edge of both of the faces IN on each of the vanes I00. The outer edge of the face IOI remains rectangularinshapeas shown at I 04.

With the vanes I00 constructed as Just described, it can readily be appreciated that fluid or liquid can pass between the surfaces IN and I 02 of the vane and slot and enter the chamber Ill just below the vane I00, and a the fluid or liquid is under pressure that the pressure of the fluid will act upon the end of the vane m to with thee-cylinder bore 00.

force the vane I00 outwardly into encasement- However, when the pump no pressure existing on either side thereof the initial rotation of the rotor 00 causes the vanes I00 to be moved outwardly due to the centrifugal force. Also, the rotation of the rotor 05 causes the vanes I00 to assume an angular position with respect to a slot I02 so that the end ofthe vane lags behind the slot thereby providing-a deflnite passageway I06 between the forward face of the vane I00 and the forward face of the slot 00 whereby fluid will enter the chamber I05. when the vane I00 assumes this position the rear face of the vane I00 will engage the upper and rearward edge of the slot 00, as indicated at I01; thereby providing a sealing engagement there between for sealing the chamber I05 from the chamber I08 which trails the vanes I00.) It is understood that each of the vanes I001 has a chamber in advance thereof and a chamber which trails the same, the chamber in advance of the vane being the compression chamber or fluid moving chamber, while the chamber trailing the vane is the suction chamber. The pressure in the chamber in advance of the vane I00 will thus provide a rearward pressure on the vane I00, to cause the rear face thereof to seal against the upper and rearward edge of the slot 09, which i in direct proportion to the pressure in the chamber in advance of the vane. Since the passage I00 permits fluid or liquid to enter the chamber I0! the vane I00 will be forced outwardly into engagement with the cylinder bore 00 by a force which is proportionate to the surface area of the inner edge of the vane exposed to thepressure, this force being relieved to some extend by the pressure exerted on the outer edge, surface of the vane I00. However, since-the inner edge 40 surface of the vane has a greater surface area exposed to the pressure than the outer surface edge the resultant of the forces will be such that the vane will be moved outwardly into engagement with the cylinder wall 96. While the fluid or liquid pressure is also exerted upon the rear face of the vane I00 below the edge I01, yet the surface area of the vane exposed to this force is less than the surface area exposed on the forward face thereof so that the resultant of the forces will be a rearwardly directed force opposed to the direction of rotation of the rotor.

This condition is true at all points on all vanes of the rotor, with the exception of one position and that is the position of the vane passing over ,the land betweenthe high and low pressure sides of the pump. When the vane is in the land he- Ween the high and low pressure sides of the I pump the pressure from the high side of the the high side of the pump, or in proportion to the pressure existing in the chamber in advance of each of the vanes .so that .as the pressure against which the pumpis working increases, the

is first started with sealing engagement of the vane with the cylinder bore 98 will be increased. Also, by the same course of events, the sealing engagement between the vane and the rearward edge of the slot 99 will be increased.

Since the angular face I03 is provided on both sides of each of the vanes I00, it can readily be 7 invention these various mechanical modifications.

) This application is a division of my copending application Serial No. 377,709, filed February 6,

1941, patented July 18, 1944, No. 2,354,076.

Having thus [fully described our invention, what we claim as new and desire to secure by Letters Patent is:

A reversible variable delivery pumpincluding, a cylinder having fluid flow passages, a rotor having therein a plurality of radiallyand axially extending slots, said rotor being Journaled within said cylinder, said cylinder and rotor being relatively movable to change the eccentricity between their axes, a generally rectangular vanein each slot, respectively, each vane having an axial dimension greater than its radial dimension, and -a thickness substantially less than the corresponding dimension of its slot whereby each vane tilts circumferentially within its slot in a direction depending upon the direction of rotation of said-rotor, the outer end of each vane slidably. engaging the walls 01 said cylinder and being shaped to give, when so tilted, substantially line contact along elements of said cylinder, each vane, when so tilted having substantially line contact with its slot on opposite sides thereof, each vane having its opposed faces chamfered along and adjacent a mid-portion of its inner edge, whereby fluid under pressure may have access to the slots when the vanes are so tilted, to thereby urge each vane radially outward.

WARREN R. TUCKER. GEORGE A. WALDIE.