US1742215A

US1742215A - Rotary fluid unit

Info

Publication number: US1742215A
Application number: US179236A
Authority: US
Inventors: Reginald J S Pigott
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-03-29
Filing date: 1927-03-29
Publication date: 1930-01-07
Anticipated expiration: 1947-01-07

Description

Jan. 7, 1930. R. J. s. PlGoTT komm! FLUID UNH Filed March 29. 1927 4 Sheets-Sheet 1 Jan. 7, 1930'. R. J. s. PlGorr 1,742,215

ROTARY FLUID UNIT Filed Maron 29. 1927 4 sheets-sheet 2 Z 10 @nvm/woz 1290i? 351g @MSM/maj mM/c Jan. 7, 1930. R. J. s. PlGoTT 1,742,215

ROTARY FLUID UNIT Filed March 29. 1927 4 Sheets-#Sheet 3 il W' Z Z4 1.9 ,Z0 7 a,

if W j j/' 52?" i 5 1, 33a lo L? 2g '357i .9 "v w" "vii n Swventoz RfI-Sllzgolt @51j 14436 Gbtomea WM5/ELA l Jan. 7, 1930. R, J s, FIGO-r1' 1,742,215

ROTARY FLUID UNIT Filed Ilarch 29. 1927 4 Sheets-Sheet 4 Snom/1to1 Patented Jan. 7, 1930 UNITED STATES PATENT OFFICE BEGINALD J. S. PIGOTT, 0F NEW YORK, N. Y.

ROTARY FLUID UNIT Application led March 29, 1927. Serial No. 179,236.

My invent-ion relates to devices for delivextremely flexible drive and is widely suitering fluids and more particularly to rotai'y able for the propulsion of motor vehicles and units of a type capable of delivering a variaother motor vehicles and other transportation ble volume of fluid per unit of time at conmeans as well as in industrial uses. Among 5 stant speed or conversely, of maintaining a other advantages of such transmissions, be- I5 constant volume at variable speed. sides the constant-speed-variable-volume fealn the present forms of rotary unitsture are that one unit may supply several gear, inipeller or otherwise-the volume of motors in parallel-such as might be a stoker fluid delivered is a function of the speed and feed-where, shouldfine motor be stalled by 10 only by varying the speed can the volume be part of the mechanism which it drives, the 60 varied. This has been a limiting factor in remaining motors will speed up to take care such units and has prevented their use where of the output of the unit and keep the mechotlierwise it would be greatly extended, not anisin to its capacity although one part has only for transferring fluids from one point to failed. Likewise, motors may be placed in another but as a means to supply and control Series to drive separate but dependent mechaa fluid motor. nisms in syiiclironism at any given speed. As

In general, my invention embraces a pluthe whole unit output must pass through each rality of revolving members enclosed in a motor, the stoppage of one will cause all of casingdriven from a source of power-as the others to stop and so prevent damage or is well known in the art. The amount of loss. 70 fluid delivered is then dependent upon the ef- The form which I have chosen to illustrate fective width of the faces of the revolving my invention is that ofagear pump although members. As long as the width of these it will be understood that other forms of r0- faces remains constant, the volume of fluid tary units having a, plurality of rotors can 5 delivered will also remain constant for anfy equally well be adapted to the same principles given speed. llowever, by changingr these e for other uses and I am not confined solely fective widths, the output of the unit may be to gear pumps. varied to any extent desired from minimum The following specification, of which the to maximum at any given speed. It is in this drawings form a part, describes my invention 39 manner that I secure a variable volume of in this preferred form. 80

delivery with constant speed and further- In the drawings:

more, may automatically maintain that vol- Fig. 1 is a side elevation of the discharge ume at any given amount by a valve arrangeside of the pump.

nient which utilizes the pressures within the Fig. 2 is an isometric of a stripped pump 35 unit to control the extent to which the faces showing the gears, spiders and follower plate.

of the revolving members are exposed for Fig. 3 is an elevation of the drive end of a any given setting of the valve. pump arranged for non-lubricating fluids.

Such units, as illustrated by pumps or Fig. 4 is a longitudinal section of a pump blowers` are widely adaptable to industrial at full volume setting. J uses where variable volume or rate of delivery Fig. 5 is a section through 5 5 of Fig. 4. 90

is desired such as for hydraulic presses, con- Fig. (i is a section through 6 6 of Fig. 4. trol of' volume in different stages of oil refin- Fig. 7 is a longitudinal section Similar to ing and in chemical processes, temperature Fig 4, but at minimum volume setting. control by fluids. supply to oil burners, draft Fig. 8 shows the valve and port arrangeaild air pressures and inniiiiiei'able other uses ment. 95 which are evident. Similarly, units embody- Fig. 9 is an isometric phantom showing the ing my invention are especially well adapted connections and passages to the valve chamto feed fluid motors and many advantages acber.

crue therefrom. This form of transmission- Fig. l0 illustrates a transmission arrange- 5" variable unit and fluid motor-provdes an ment. 10

The pump casing is shown at 1, supported by the base 2 and having an inlet 3 and an outlet 4. The casing is closed by the head 7 with bolts or studs 8. In the lower part of the casing is a shaft 9 (Figs. 4 and7) which lits in the casing and head as shown and is held against movel'nentby. a set screw (not shown) in the casing end. On the casing end of this shaft is a spider 10 having a bearing 11 and a gear 12 having a bearing 13 in which is an ofl'set 14 against which the gear 12 abuts. This spider and gear are always in engagement (Fig. 2) and both fit closely within the circular portion of the cas ing where they revolve. The inner portion of the spider is hollow to a depth approximately equal to the width of the face of the gear 12 and is so arranged Circumferentially as to be the complement of the gear; that is, the spider conforms in shape to the tooth spaces and is of the same diameter as the gear so that, in effect, the spider acts as a movable wall or sealing means as it closes over the gear in the manner to be described later.

Above the fixed shaft 9 is the power driven shaft 15 which turns in the bearings 16 of the casing and 17 of the head. Fixed to this shaft by the key 18 is another gear 19 adapted to mesh with the gear 12. Also on this same shaft and in engagement with the gear 19 is the spider 20 of similar construction to the spider 10 and having a like relation to gear 19. So far it will be seen that gear 19 will drive gear 12 and that

spiders

20 and 10 will revolve with their respective gears and that the effective width of the gear teeth in engagement can he varied by the spiders coming over their respective gears. In order that these movements may be simultaneous, I provide a follower plate 21. This follower fits over a reduced end of the spider 20 and is retained by the nut 22 (Fig. 4) the spider being free to rotate while the follower is stationary. Extending downward, the follower is developed into a hollow portion around the shaft 9 with its outer edge abutting against the lower gear 12 and flush with the inner face of spider 20. Gear 12 is retained against the follower plate 21 by the nut 23 on the bearing 13 which rotates with gear 12 on shaft 9. It will thus be seen that any longitudinal movement of the follower 21 will move the spider 20 over the gear 19 and the gear 12 into the spider 10 to decrease the degree of engagement of the working gears so that-the two spiders fitting closely within the casingthe effective width of the gear faces 24 (Flg. 4) is reduced and may be still further reduced to its minimum shown in Fig. 7 at 24.

When lin operation` the internal pressure developed in the pump will act longitudinally against the faces of the spiders and against the exposed area of the follower plate and tend to force the upper spider and the fOllower plate to their extreme position toward the head 7 and thus keep the gears in their maximum degree of mesh as in Fig. 4 and the pump at its greatest output. In order to overcome this and permit of any easily made and stable setting of the follower plate 21 with its attached spider 20 and gear 12 at any desired point for the particular volume or delivery wanted, I provide a balanced valve whereby the pressures are balanced andthe follower-spider-gear assembly will automatieally seek its position according to the setting of the valve.

Within the follower 21 (Figs. 8 and 9) is apvalve chamber 25 in which fits a piston valve 26 having

pistons

27 and 28. Toward the extremities of this valve chamber are two

exhaust ports

29 and 30 connected by the cut 31 in the side of the follower 21. A second exhaust passage 33 leads from the valve chamber across the follower 21 to an outlet 34 on the inlet or suction side of the pump. Therefore the portions of the valve chamber nutside of the

pistons

27 and 28 will always be open to the suction of the pump. From the outlet or pressure side of the pump another cut 35 in the side of the follower 21 leads to the port 36 in the central portion of the valve chamber. Therefore the space between the

pistons

27 and 28 of the valve will always be at the output pressure developed by the pump. Also leading from the valve chamber is a port 37 and passage 38 leading upward to theannular groove 38 in the rear of spider 20 which in turn connects with the passage 38b to the interior of this spider. Also a port 39 goes to the passage 40 and thence to the point 41 where it opens into the circular cut 42 in the face of the follower 21. concentric series of holes 43 passing through the gear 12 and opening into the inner portion of the spider 10 (Figs. 4, 8 and 9). Likewise, there is a passage 44 connecting the valve chamber with the lower recessed Portion of the follower plate.

The valve/26 may be connected to any suitable actuating mechanism such as is shown This circular cut 42 registers with al in Fig. 1 where the valve is connected to the operating arm 45 pivoted by the link 46 and having a guide 47 upon which the arm 45 maybe locked in any position by the wing .nut and bolt 48.

The operation of the pump is as follows. The shaft 15 will drive the gear 19 and carry the spider 20 with it-these two always being in some degree of engagement. Gear 19 drives gear 12 which in turn carries spider 10 with it-these two also being always in some degree of engagement (Fig. 2). Then with the parts in the positions of Fig. 4,

the pump will deliver maximum volume and the valve will be in the position of Fig. 8 with passages 38, 4() and 44 closed by the

pistons

27 and 28. The internal pressure acting against the faces of the spiders and follower late will tend to force them apart and keep t e gears at maximum effective width. The pressure entering through the cut 35 and port 36 will be confined between the

pistons

27 and 28 and be without effect. The

exhaust ports

29 and 30, connecting to the exhaust opening 34, remain open as always.

If it is desired to change the output of the pump-to reduce the volume or outputthe valve 26 is advanced into the valve chamber the desired amount. In so doing, a portion of the port 44 is uncovered by the pi'ston 27. This results in pressure flowing through cut 35, ort 36, between the pistons of the valve an out port 44 to all of the space between the back of the follower plate 21 and 'the head 7. Also

ports

37 and 39 are uncovered by piston 28 so that the space between the upper spider and gear is open to the exhaust port 30 through passage 38,

roove 38 and passage 38b and a similar space p 1n the lower gear and spider is open to the exhaust port 30 through holes 43 in gear 12, circular cut 42 in the follower and the passage 40. Therefore, the pressure exerted behind the follower plate as just described will force it forward; the fluid between the gears and their spiders will be exhausted as just described and the upper spider 20 will move over its gear 19 while the lower gear 12' will move a corresponding amount into its spider 10. Thus the effective width of engagement of the gears will be decreased and the volume, or output, of the pump is reduced accordingly. This forward motion of the followerspider-gear assembly will continue until

ports

38 and 44 are again closed by this followingup of the valve by the aforesaid assembly or a balance of pressures established at which time the follower-spider-gear assembly comes to rest and the pump will continue to deliver the reduced volume. If the forward movement of the valve is continued, the effective width of the gear teeth will continue to be reduced until the position of Fig. 7 is reached which is that of minimum or zero volume of the ump.

If it is desired to increase the volume delivered by the pump, the valve is drawn outwardly and functions as follows. The port 44 is uncovered so that the fluid formerly under pressure between the follower 21 and the head 7 is opened tothe exhaust and will flow out through the valve chamber and the passage 33 to the exhaust opening 34 (Figs. 8 and 9). The

ports

37 and 39 will be uncovered so that fluid under pressure will flow through cut 35, port 36, between the

pistons

27 and 28 and out of port 37, passage 38, annular groove 38a to the inside of the spider 20. Fuid will also pass out of port 39, passage 40, circular cut 42 and through the holes 43 in gear 12 to the in side of spider 10. Ther-eL fore, as pressure 1s removed from behind the follower and there is pressure back of the ears in the spiders as well as against the aces of the spiders and follower, the follower will move toward the head 7, the gears will be drawn into a greater degree of engagement and the effective width of the gear teeth increased to raise the pump volume.

Consequently, it will be seen that b a movement made easily and without e ort the valve is shifted to change the volume of the pump at will without change of speed and that the elements of the pump will adjust themselves to their proper positions according to the position of the piston valve as so moved.

Theoretically, the follower will move to a position where the

ports

44, 37 and 39 are closed by the

pistons

27 and 28 but it may be that the position of equilibrium may be slightly to one side or the other but this in no way affects the operation of the valve or ump inasmuch as, when equilibrium is established, the follower will retain the psition to which it moves until the valve setting is again changed. It is also obvious that, instead of having the valve 26 manually operated as shown, it may equall well be arranged to adjust automatically t e position of the follower plate-and hence the output of the pump-in accordance with conditions of flow, pressure, temperature, etc.

The foregoing description contemplates the use of a fluid having lubricating qualities or where the faces of the rotors can be lubricated but where other fluids are used, the wear on the rotors would be undesirable and lead to excessive leakage. In such event, I extend the

shafts

9 and 15 and mount upon them a pair of gears 49 and 50 (Fig. 3) preferably of finer pitch than the pumping gears or of any desirable pitch where rotors other than gears are used. The driving is then done by these gears and while the pumping rotors will mesh as before, there will be no driving as between them and consequently no wear.

In Fig. I show in diagram form a transmission to which my invention is well adapted. This pump is shown at 51 and its valve control at 52. The Huid passes through pipe 53 to motor 54, is exhausted through pipes 58 and 59 to tank 60 where it is again taken up by the pump through pipe 61. The motor 54 is shown as being of .the gear type for low speeds where the gear 55 is smaller than the gear 56 on the driving shaft 57. Such a transmission with a pump embodying the principle of my invention provides a range of all motor speeds between minimum and maximum without change in the speed of the pump. Also this form of transmission is invaluable for all forms of transportation, speed changers, industrial and marine uses, etc., and may be combined in a very small space, is simple, ef-

iicient and rugged. No packing or other sealing means are necessary and runnin the ump at relatively high periphera spee the fluid leakage past the rotors will be a ver small percentage of the pump volume an practically constant.

It will be understood that the preferred form of m invention just set forth in the foregoing t escription of a pump and a transmission is illustrative and that many changes and adaptations in design and combination may be lnade without departing from the spirit thereof, or affecting the principle and I include all such within the scope of my claims.

I claim:

1. A rotary pum tors, one being fixe and the other bein another shaft, axial? having a pair of roupon a rotatable shaft axiall movable upon mova le means adapted to move over an closel fit around said fixed rotor, other similar but axially fixed means Iadapted to receive and closely fit around said movable rotor and a connection between the axially movable means and gear.

2. A rotary pump having a fixed rotor and a slidable spider, a fixed spider and a slidable rotor and a follower plate connecting the slidable gear and spider.

3. In a rotary pump having rotors in engagement, a shaft on which is fixed a rotor and a slidable spider, another shaft on which is a slidable rotor and a fixed spider and a follower plate connecting the slidable spider and the slidable rotor.

4. A rotary pump having rotors in engagement, splders coacting with each of the rotors and a follower plate associated therewith, means to distribute the internal pump pressures to selected points with relation to said rotors, spiders and follower plate and a valve device arranged to control said distribution of pressures.

5. A rotary pump having rotors, means coacting with each rotor to vary the volume of the pump independently of its speed, an element connecting one of said means and one of said rotors and a valve device adapted to maintain said volume varying means in any selected position.

6. In a rotary pump, a fixed gear and a slidable spider on a shaft, a slidable gear in engagement with the fixed gear and a fixed spider on another shaft, a follower plate connecting the slidable spider and the slidable gear and a valve device in said follower plate in association with passages to selected points within the pump.

7. A rotary pump havin a casing containing a fixed rotor and a sli able spider on one shaft, a slidable rotor and a fixed spider on a second shaft, a follower plate connecting the slidable rotor and spider and a pair of meshed gears mounted on said shafts exterior to said casini 8. rotary pump havin one shaft carrying a slidable spider and a xed gear, a second shaft carrying a fixed spider and a slidable gear in engagement with the fixed gear, a follower late connecting the slidable s ider and slidab e gear and a valve device within said follower plate adapted to maintain the connected slidable gear slidable spider and follower plate in any selected position.

9. A rotary pump having a shaft carryin a slidable s ider and a fixed gear, a secon shaft carrymg a fixed spider and a slidable gear in engagement with the fixed gear, a follower plate connecting the slidable spider and slidable gear; a valve device within said follower plate adapted to maintain the connected slidable gear, slidable s ider and follower plate in any selected position and means exterior to the pump to actuate said valve dev1ce.

10. A rotary pum havin a casing containing a fixed rotor an a slidale spider, a fixed spider and a slidable rotor, a follower late connecting the slidable gear and slidab e rotor and a valve Iwithin said follower plate adapted to distribute the pressure within the casing to selected points with respect to said rotors, spiders and follower plate.

11. A rotary pump having rotors in engagement and means coacting with each rotor to vary the volume of the pump independently of its speed; said means bein actuated by the pressures generated within t e pump.

12. A constant speed, variable volume pum) having rotors in engagement and means acte upon by the ressures generated within the pump to vary t e degree of engagement of said rotors; said means forming a movable wall to seal the tops and ends of the rotors and forming a closed chamber to the extent of the meshing width of the gears.

13. A rotary pump having rotors in engagement and means co-actin with each rotor to vary the effective portlons of said rotors.

14. A rotary pump having rotors in engagement, means co-acting with each rotor to vary the effective portions of these rotors and a valve device controllin said means.

15. A constant spee variable volume pump having rotors in engagement and means to vary the volume of the pump independently of its speed; said means coacting with each of the rotors to form the walls of a chamber extending the meshing width of the gears.

16. A constant speed, variable volume pump having rotors in engagement, means to vary the volume of the pump independently of its speed and a valve device contained in the means; said means coacting with each of the rotors to form the walls of a chamber extending the meshing width of the gears.

17. A variable volume, constant speed pump havinglrotors in engagement and means coacting wit each rotor to vary the meshin width of the gears in response to pressure di ferentials created within the pump.

18. A variable volume, constant speed pump having meshed rotors in a chamber and means coacting with each rotor to form a movable wall of said chamber.

19. A variable volume, constant speed pump having meshed rotors in a chamber,

means coacting with each rotor to form a movable wall of said chamber and a valve device contained in said means.

In testimony whereof I have signed my name to this specification this 26th day of March, 1927.

REGINALD J. S. PIGOTT.