US2247922A

US2247922A - Pump

Info

Publication number: US2247922A
Application number: US228975A
Authority: US
Inventors: Robert S Potter
Original assignee: Yale and Towne Manufacturing Co
Current assignee: Yale and Towne Manufacturing Co
Priority date: 1938-09-08
Filing date: 1938-09-08
Publication date: 1941-07-01
Anticipated expiration: 1958-07-01

Description

R. S. POTTER 2 Sheets-Sheet 1 lNVENTOR July 1, 1941. s, POTTER PUMP Filed Sept. 8, i938 2 Sheets-Sheet 2 I IIIIIA'IIII/I/I 4 lllllllll I lllllllllllllill INVEN'IDOR 41,4 x mar BY TORNEY IIIIIIIIIAIIII Patented July 1, 1941 PUMP Robert S. Potter, Stamford, Conn., assignor to The .Yale & Townc Manufacturing Company,

Stamford, Coma, a corporation of Connecticut Application September 8, 1938, Serial No. 228,975

- started, this pressure 'being gradually built up 13 Claims.

This invention relates to pumps, and more especially to control means for pumps of large volume. I

Those skilled in the art will of course appreciate that while my invention relates more especially to large pumps, it may be useful on other types of pumps.- Those skilled in the art will also appreciate that while I shall describe my invention as applied to a particular type of pump, that is, the type shown in the Waite Patent No.

2,018,693, granted October 29,1935, it is alsoapplicable to other types of pumps More particularly, my invention relates to the. means for effectively actuating and controlling a pump of large volume, so that the pump may be driven by a relatively small motor. Thus, due

toward a. predetermined maximum to gradually increase the volume of the main pump. Through the arrangement of a suitable by-pass valve in the auxiliary pump outlet side, whenever the pressure developed by' the auxiliary pump is greater than a predetermined value, the excess pressure will be relieved through the by-.pass valve, all as will be well understood by those skilled in the art.

I am able in my pump to obtain the basic feature set forth by Waite in his patent, that is,

, the feature whereby when the pressure on the to the manner in which the pump of my invention'is controlled. it starts at zero or low volume and gradually reaches full pumping volume. Thereafter, the volume is controlled, preferably, without by-passing pumped liquid.

- Those skilled in the'art fullyappreciate that it requires a comparatively large electric motor 'to start a three hundred gallon per minute pump equipped with the usual by-pass. In such a pump. full volume must be pumped immediately. If a pump of the type disclosed by Waite is utilized, that is, a pump requiring no by-pass, a fairly high torque motor is also required because the maximum volume must be pumped at once. It should of course be understood that in Waite, because there is no by-pass, by-pass pressure need not be overcome after the pump is once started. This does not relieve the necessity for alarge starting motor.

In my invention, I utilize the basic structure disclosed in the Waite patent including a volume controlling piston. However, while'in the Waite patent the control piston is always pressed by its spring intov a full eccentric or maximum position, in my pump, the volume control piston is normally in a, non-pumping or concentric position, and therefore it is possible to start the rotation of the pump with a minimum of effort. Thereafter, pressure is brought against the volume control piston in a novel manner so as to force it into a more and more eccentric position against the force of its spring so as to gradually increase the pumping capacity.

For applying pressure to the volume control piston, an auxiliary pump is utilized which is preferably mounted on the main pump casing and is driven preferably by a take-off from the main pump drive shaft. This auxiliary pump develops pressure as soon as the main pump is discharge side of the main pump increases beyond a predetermined degree, the pump volume -is decreased, thereby making it unnecessary toutilizes. lay-pass valve. In the preferred form of my invention, the pressure on the discharge side of the main pump is led to the side of the volume control piston opposite the side to which is applied the pressure from the auxiliary pump.

Therefore, when the pressure on the discharge side of the main pump increases beyond'a desired predetermined limit, it will merely operate against the volume control piston to move it into a more and more concentric position so as to decrease the volume, all against the pressure from the auxiliary pump:

Summarizing my contribution, it will readily be seen that through my invention it is possible to employ a drive motor for a large volume pump of a mating required :only for the movement of the amount of liquid desired, the usual heavy starting load of a large volume pump being eliminated. It is also seen that I am able through the controls I have already explained generally to control very effectively the volume of my pump under all conditions.

Having thus described generally my invention and its contribution to the art, I shall now refer to the drawings in connection with which I shall describe a preferred form of my invention. In

the drawings, Fig. 1 is a partial vertical-section and elevation showing my pump construction.v

Fig. 2 is a view looking. down on the pump of Fig. 1 with certain parts omitted for clarity. Fig. 3 is a section taken substantially along the lines H of Fig. 1 with certain parts omitted, and showing the construction of my pump, this construction being better shown in the Waite patent referred to. Fig. 4 is a section takerralong lines 4- 4 of Fig. 1, while Fig. 5 is' a section taken along lines 5-5 ofFig. 4.

Referring now more particularly to the drawings, and especially to Figs. 1 and 3, reference numeral I indicates a rotor having a transverse slot II in which reciprocates a pumping piston I2. This pumping piston I2 is reciprocated relatively to the rotor ID as that rotor rotates, be? cause of its positioning relatively to an eccentric shuttle block I3. The block I3 is itself maintained in an eccentric position by a pin l4 rotatable relatively to the shuttle block l3 through a sleeve l5. As has been previously indicated, the pump construction so far described is that shown in the Waite patent referred to, and does not per se form part of this invention.

The rotor l0 rotates in a chamber formed by the union of a main casting I6 and side plates I I1 and 8 united by a series of bolts l9, as best illustrated in Figs. 1 and 2. The intake side of the pump is designated in the various flguresby reference numeral 20, while the pressure or outlet side of .the pump is designated by reference numeral 2|. During each revolution, the piston l2 executes one pumping stroke relatively to the slot l and rotor III, while the shuttle block l3 will move through one pumping operation relatively to-the

openings

22 and 23 formed in the rotor. Thus, there will be two pumping strokes relativey to the pressure side of the pump 2| during each revolution of the rotor 50.

Secured against the plate I 1 is a cylinder 24 capped at its upper end, as is best shown in Figs. 1 and 4, by a plate 25 held through bolts 26, and at its lower end by a plate 21 held through bolts 28. The cylinder 24 is open as at 29, the opening being capped by a plate 36 held by a series of bolts 3.|. Mounted for sliding movement within the cylinder 24 is a hollow piston 32. A spring 33 rests at one end against the plate 25, and at its other end against a seat 34 within the piston 32, thus urging the piston downwardly into its position of Figs. 1 and 4.

The pin l4 which, as was previously described, determines the eccentricity of the shuttle -l3 and therefore the volume which will be pumped, passes through a bore 35 in the piston 32 and is secured to the piston by a nut 36, so as to slide with the piston as determined by a slot 31 formed in the plate H. The slot 31 will determine the limits within which the piston 32 and the pin M will move under the influence of the spring 33 in one direction, and under liquid pressure in a reverse direction, as will be described presently.

One end of the cylinder 24 in which the piston 32 slides, is connected through a passage 38 in the end plate l1 and a passage 39 in body l6 to the pressure side 2l of the pump, so that the pressure side of the pump will always be in communicagian with the cylinder, and therefore the piston The end of the piston 32 opposite the spring actuated end has secured thereto a leather washer 46 through means of a bolt 4| and a metal washer 42, the leather washer acting in the nature of a piston ring. The lower endof the cylinder 24 is in communication through a bore 43 in the plate II, a bore 44 in the body l6 and a screw threaded bore 45 in the plate l8, with a screw threaded nipple 46, which in turn leads through

various connections

41 and 48 to the presure side 49 of a pump 56.

This pump 56 is illustrated in Figs. 1 and 2 and is mounted through its base 5| on an extension 52 of the plate l8, that is, in effect, on the casing of the main pump. Its actuating shaft is coupled through the coupling 53 to a shaft 54 traversing a stufllng box 55 andterminating in a portion 56 on which is mounted a gear 51. The

will rotate the gear 51, which will in turn rotate shaft 54, 46, which through coupling 53 will rotate the rotor of the pump 58. The pump 50 is preferably the same type of pump as the main pump, only much smaller and not equipped with a volume control.

The intake side of the pump 50 is connected through pipe 6| and a further pipe 62 to a reservoir 63. This, is necessary only when the main pump is to pump nongubricating or other liquid which is not suitable for the purpose of the liquid to be pumped by pump 50. The outlet side of the pump, in addition to being connected through the

pipes

41, 48, nipple 46and various passages to the lower side of the cylinder 24, is also connected through pipe 64 to a by-pass valve 65 and thence through, pipe 66 to either the intake pipe St or through pipe 62 to the reservoir 63. The by-pass valve may be-of any type which may be set to a predetermined pressure, and functions in a way to be described presently.

Having described the mechanical construction of my pump combination, I shall now explain its action. When the pump drive shaft 60 is at rest, there is of course no pumping action in the auxiliary pump 50, and no pressure is being transmitted to the lower side of the cylinder 24 against the lower side of piston 32. The spring 33 therefore presses against piston 32 urging it to its lowermost position determined by slot 31. In this lowermost position, the pin l4 will be in full concentric position.

If now the drive shaft 66 is rotated through suitable means, no pumping will take place because of the concentri position of the pin l4. The rotation of the drive shaft 68 does, however, through gears 58 and 51 cause rotation of the pump 56 and consequent generation of fluid pressure by that pump. The pump 50 will accept liquid from the reservoir through pipes 62 and 6|, and will force it outwardly through'pipe 48, elbow 41, nipple 46 and

passages

45, 44, 43 into the cylinder 24 and against the lower side of the piston 32.

As the pressure from pump increases, the

piston 32 will be gradually forced upwardly against the pressure of the spring 33 until it reaches the position of Fig. 1, which is its maximum pumping position. Should the volume of the main pumpat its maximum pumping position illustrated in Fig. 1 be greater than desired, then the by-pass valve 65 of the auxiliary pump 50 may be set to a pressure which is below the pressure necessary to maintain the piston 32 in its position of Fig.1. If this is done, then, when the pressure from pump 56 is greater than that for which the by-pass, valve ,65is set, fluid ,will flow upwardly through pipe 64 past the by-Iaass valve 65 and into pipe 66, rather than through the pipe 48 and elbow 41 .until the pressure drops. Thus, by

suillcient to force the-cylinder opposite 2 ia. It is the function of

passages

38 and 39 to 'control through piston 32 the volume oi my ing volume of said pump,

main pump,- in accordance with the volume which is demanded.

Assuming that a valve or other means at the end of the pipe Ila in Fig, 1 is closed fully or partially, it will be appreciated that the pressure in chamber 2| will gradually increase. This will be applied through

passages

38 and 39 against the piston 32, and will tend to move piston 32 against the pressure being exerted by the pump 50. This pressure from the main pump may become relatively great, as where the entire flow through pipe 2la is cut oil, and may become 32 downwardly into a position bringing the pin it into full concentric position, thus cutting oii the volume of the main pump to zero. despite the pressure being exerted by the pump 50. In this way, the volume of the main pump may be adequately controlled without by-passing pumped fluid, much in the same way as is controlled the volume of the pump of the Waite Patent N0. 2,018,693.

Those skilled in the art will of course appreciate the considerable advance inthe art which is made by my construction over that ot'waite.

It may be well, however, to point out that my application is owned by the manufacturers of the construction shown in the Waite patent.

Shouldthere be any leakage of fluid past the This can take place leather washer carried by the piston 32, I

have provided meansbest shown in Figs. 1, 4

and 5, for carrying oil. that liquid. Thus, there is a counter bore II formed within the cylinder 24 and connected with passages Ii and II. In a pump assembly rotor intended for rotation in one direction, only the pipe Ii is used, it being connectedv to the intake side 20 of my pump,-

thus adequately disposing of the fluid which may leak past the washer l0.

My pump is so constructed that it may be spring to a pumping the pressure thereafter developed-.by said main readily assembled for operation in either one of r directions. Thus, there are two passages 39 shown inthe pump body II, as is readily seen from Fig. 1, just as there are two passages H and I2. I believe that those skilled in the art will now fully understand the operation or my pump combination, and that no further explanation is required.

I new claim:

main pump, control means auxiliary pump is controlled and thereby the volume of said main pump.

4. In a combination of the class described, a main pump, control means for varying the pumping volume of said pump, means normally urg-- ing said control means toward a non-pumping position whereby when said pump operates it will pump substantially no'fluid, an auxiliary pump, and means of connection between said auxiliary pump andsaid control means whereby the output of said auxiliary pump urges said control means toward a pumping position against the said means urging said control means toward a non-pumping position, and additional means oi. connection between pump and said control means whereby the out- 'put of said main pump also urges said control means toward anon-pump s position.

5. In a combination of the class described, a main pump, control means for varying the pumping volume of said pump, 'a spring control means in agdirection corresponding to non-pumping of said main pump, an auxiliary P auxiliary pump to said control means whereby the pressure developed by said auxiliary pump moves said control means in opposition to said position, and means whereby pump urges said control means in a non-pumping direction.

6. In a combination of the class described, a main pump, control means for varying the pumping volume, of said pump. a spring normally urging said control means'in a direction corresponding to non-pumping of said main pumpwhereby when said pump operates it will pump substan-' I tially no fluid. an auxiliary pump. means of con- 1. In a combination of the class described, a

main pump, control means for varying the pumping volume of. said pump, means normally urging said control means toward a non-pumping position whereby when said pump operates ,it

will pump substantially no fluid, an auxiliary pump, and means of connection between said auxiliary pump and said control means whereby the output of said auxiliary pump urges said control means toward a pumping position against the said means urging said control means toward a non-pumping position. i

2. In a-combination of the class described, a main pump, control means for varying the pumping volume of said pump, a spring normally urging said control means toward a non-pumping position whereby when said pump operates it will pump substantially no fluid, an auxiliary pump, and means of connection between said auxiliary pump and said control means whereby the output of said auxiliary pump urges said control means against said spring toward a pumping position.

nection between said auxiliary pump and said controimeanswhereby the output or said auxiliary pump urges said control means in a pumping direction, and additional means or connection between the output side of said main pump and said control means whereby the output of said main pump also urges said controimeans in a non-pumping direction.

7. In a combination of the class described, a main pump, control means (or varying the pumping volume of said pump, a spring normally urging said control means in a direction corresponding to non-pumping of said main pump whereby. when said pump operates it will pump substantially nov fluid, an auxiliary pump, means of connection between said auxiliary pump and said control means whereby the output of said auxiliary pump urges said control means in a pumping direction, additional means of wnnection between the output side of said main pump andsaid control means whereby the output of said main pump also urges said control means in .a non-pumping direction, and pressure relief means in the output line of said auxiliary pump whereby the volume of said main pump is controlled.

In a combination oi the class described, a

position, and a pressure reliei valve whereby the pressure developed by said the output side or said main rs s said.

means connecting the output side of said main pump, control means for varying the pumping volume of said pump, a spring urging said control means in a direction corresponding to non-pumping of said main pump, an auxiliary pump, means connecting the output side of said auxiliary pump to said control means whereby the pressure developed by said auxiliary pump moves said control means in opposition to said spring to a pumping'position, a pressure relief valve whereby the pressure developed by said auxiliary pump is controlled and thereby the volume of said main pump, and means whereby the pressure-thereafter developed by said main pump urges saidcontrol means in a non-pumping direction.

9. In a combination of the class described, a main pump having an eccentric volume control member, a piston for controlling the eccentricity of said volume control and therefore the pumping volume of said pump, a spring urging said piston into a position corresponding to a non-pumping or -concentric position of said volume control, an auxiliary pump, means leading from the output side of said auxiliary pump to said piston whereby the pressure developed by said auxiliary pump moves said piston against the pressure of said spring to a pumping position, and means leading from said main pump to the opposite end of said piston whereby the pressure developed by said main pump assists said spring in urging said piston to a concentric or non-pumping position.

10. In a combination of the clas described, a main pump having a casing and a pumping mem ber movable in said casing, a drive shaft for actuating said pumping member, volume control means for said main pump, means normally bias ing said control means into non-pumping posi: tion, an auxiliary pump supported on the casing of said main pump, a power connection between the drive shaft of said main pump and said auxiliary pump, and means whereby the output of said auxiliary pump moves said volume control means into pumping position against the said means normally biasing said control means into non-pumping position.

11. In a. combination of the class described, a main pump having a casing and a pumping member movable in said casing, a drive shaft for actuating said pumping member, volume control means for said main pump, means normally bias- I of said main pump, a power take-off from said drive shaft to said auxiliary pump for operating said auxiliary pump, and means of connection between said auxiliary pump and said'volume control means whereby the output of said auxiliary pump moves said volume control means into pumping position against the said means normally biasing said control means into nonpumping position.

12. In a combination of the class described, a main pump having a casing and a pumping member movable in said casing, a driveshaft for actuating said pumping member, eccentric volume control means for said main pump normally biased into concentric or non-pumping position, an auxiliary pump supported on the casing of said main pump, a power take-off from said drive shaft to said auxiliary pump for operating said auxiliary pump simultaneously with said main pump, and means of connection between the output side of said auxiliary pump and said eccentric volume control means whereby the output of said auxiliary pump moves said volume control means into eccentric or pumping position.

13. In a combination of the class described, a main pump having a casing and a pumping element movable in said casing, a drive means for said pumping element, eccentric positioning means for said pumping element including a piston and a cylinder in which said piston slides,

a spring in said cylinder pressing said piston and therefore said eccentric positioning means into a non-pumping position, an auxiliary pump secured on the casing of said main pump, a power take-off from said drive means for said main pump adapted to drive said auxiliary pump, a passage connecting the output of said auxiliary pump with said cylinder whereby the pressure developed by said auxiliary pump actuates said control piston against said spring whereby to move said piston and said eccentric positioning means into a pumping position, and means of communication between said cylinder and the output side of said main pump whereby the pressure developed by said main pump assists said spring in moving said piston and said eccentric positioning means into a non-pumping position.

ROBERT S. POTTER.