US1696635A

US1696635A - Air and water pump in combination

Info

Publication number: US1696635A
Application number: US650519A
Authority: US
Inventors: Irving C Jennings
Original assignee: Nash Engineering Co
Current assignee: Nash Engineering Co
Priority date: 1923-07-09
Filing date: 1923-07-09
Publication date: 1928-12-25
Anticipated expiration: 1945-12-25
Also published as: DE445764C; GB218995A; FR584425A

Description

Dec, 25, 1928. 1,696,635

I. c. JENNINGS AIR LANDWATER Wm IN comifmmzou @riginal FildiJuly e, 1923 5' Sheet'wsheet 1 l. (1. JENNINGS AIR AND WATER PUMP IN COMBINATION Original Filed y 391923 5 Sheets-Sheet 2 Dec. 25, 1928.

l. C. JENNINGS AIR AND WATER PUMP IN COMBINATION OriginalFiled July 9, 1923 5 Sheats-$ht Dec. 25, 1928. 1,696,635

I. C. JENNINGS AIR AND WATER PUMP IN COMBINATION Original Filed July 9,. 1923 5 Sheets-Sheet 5 W WM 2 "132% Patented Dec. 25, 1928.

UNITED STATES 1,696,635 PATENT OFFICE.

IRVING 0. JENNINGS, OF SOUTH NORWALK, CONNECTICUT, ASSIGNOR TO NASH ENGINEERING COMPANY, OF SOUTH NORWALK, CONNECTICUT, A CORPORATION OF CONNECTICUT.

AIR AND WATER PUMP IN COMBINATION.

Application filed July 9, 1923, Serial No. 650,519. Renewed April 12, 1928.

The present invention relates to pumping apparatus and particularly to that type which is adapted for use in connection with systems where it is desired to handle air and water under pressure less than atmospheric such, for example, as vacuum steam heating systems. The pumping apparatus shown and described herein embodying the invention is particularly designed for use in connection 0 with the fiat boxes of paper machines. Heretofore the air and water pumps for such fiat boxes have been separate and driven by individual motors. According to the present invention the air and water pumps are both mounted on a single shaft and driven from a single source of power, which may be a motor directly connected to the shaft or a belt drive.

One of the principal features of the present invention resides in the construction of the pumping unit, the air and water pumps being removably secured together in such manner that any one of a seriesof water pumps can be combined with any one of a series of air pumps. As the construction is much simpler than the prior combined units, it is possible to manufacture a pumping unit at less cost than heretofore. There is. also a great saving in the capital tied up in manuactured stock at the factory and agents warehouse To illustrate according to the present invention, suppose there are'three water pumpsand three air pumps. Any one of the water pumps can be combined wit any one of the air pumps to make a pumping unit. Consequently with the said three water pumps and three air pumps, nine combinations of pumping units are-possible. Thus instead of being obliged to manufacture and carry in stock nine pumping units of the old style (that is to say nine units each consisting of a water pump and an air pump) according to the present invention it is only necessary to carry three water pumps and three air pumps. 6

Another feature of the invention resides in the construction of the pumps whereby the opposite heads are removable for the purpose of givin access to the interior of the pumps and the impellers.

Another feature of the invention resides in providing the inlets and outlets for both pumps in the main portions of the pump 4-4 of Figure 3;

Another feature resides in the arrangement whereby hydraulic b-alance'of. the impeller of the water pump is obtained, thus reducing and practically eliminating any axial thrust 6 on the shaft of the pumps.

Another feature resides in the provision of an improved means for adjusting the shaft of the pumps axially, so'that the impeller of one of the pumps may be accurately and delicately adjusted axially, the impeller of the other pump being held against axial movement by the walls of its casing.

Other objects and features of novelty willbe apparent from the description taken in connection with the drawings, in which Fig. 1 is a side elevation of the pump mechanism embodying the invention with adjacent attached parts of the system in which it is-used;

Fig. 2 is an end view of the mechanism shown in F igure 1 looking from the right Fig. 3 is a vertical longitudinal section through the pump mechanism embodying the invention;

Fig. 4 is a horizontal section on the line Fig. 5 is a vertical section on the line 55 of Figure 3 looking to the right;

Fig. 6 is an enlarged longitudinal section of the adjustable ball bearing support for the drive shaft shown in Figure 3 at the right; and

Fig. 7 isa side view of onev of the ring nuts used in said adjustable bearing.

Referring first to Figures 1 and 2 which show side and end views of the pump mechanism together with the adjacent parts of the system with which it may be connected in use. there is a vertical container or tank 10 infixed position adapted to receive air and Water through suitable piping which enters it through the header 11 carried by the container 10 slightly above its central portion. This-water and air may be that from the flat boxes in paper mills but it is of course adapted for receiving air and Water coming from other sources.

A centrifugal water pump in the housing 12 draws water from the lower portion of the container through inlet pipe 13 shown in dotted lines in Figure 1. The water thus drawn in is discharged by the centrifugal water pump through pipe 14 and is conveyed to any point desired for use. The pipe 15 at its lower end is connected to the top of the water pump housing and having its other end connected to the upper part of the container 10 is for the purpose of allowing any air which may enter the water pump through the inlet when the water is too low or by leakage to escape and return to the upper part of the tank. Air in the container 10 is drawn off through pipe 16 connected to its upper end by the air pump in the housing 17 entering at the rear of the housing, as shown in Figure 1, the air being discharged from theair pump through the outlet opening 18 into the open air as shown. If desired however a pipe 95 Fig. 2 may be connected to the outlet 18 so as to convey the air to a distance before it is discharged. In commercial use of the device some known form of automatic control is desirable and should be used so as to maintain a substantially uniform water level in the container 10 and substantially uniform air pressure in that container above the water. Such mechanism however is well known in the art and forms no part of the present invention and is therefore not shown or described in this application. An automatic control mechanism where the pumps are operated by an electric motor in a similar system is disclosed and claimed in my prior Patent N 0. 1,447,854 granted March 6, 1923. As above stated, the present invention relates to the structural characteristics of the pump mechanism. 7

Referring now to the pump mechanism it will be noted from an inspection of Figures 1, 3, and 5 that the air pump housing 17 is supported on a stand 19 by longitudinal.

flanges 20- having outturned lower end portions fitting the surface of the stand 19 and these flanges are formed on the main body portion 21- of the housing.- They constitute the support for not only the air pump'housing but also for the water pump housing and the drive shaft. The air pump housing. includes the main body portion 21 above mentioned.

which has the end wall 22 spaced a material distance from the adjacent end wall 23 of the casing for the rotor 24, thus forming-a space for the air between them. The housing 17 of the air pump also includes the head portion 25 which is made separately from the main body portion, the two portions being divided on substantially a vertical plane at the end of the'rotor and the end 26 of the rotor casing constitutes a part of the header portion. This end wall 26 of the rotor casing is spaced from the end wall 2710f .theheader a materialdis tance so as to form an air space between them. A drive shaft 28 passes centrally through the two portions of the air pump housing and is keyed to the inner cylindrical or hub portion 29 of the rotor so as to rotate together but the connection is such as to permit relative longitudinal movement between the shaft and the rotor.

The inlet pipe connection 30, as shown 'in Figures 4 and 5, is a part of the main body portion 21 and it has next to the periphery of the rotor casing an enlarged portion 31 extending partly around the rotor casing and having a slot 32 (see Figure 4) on the side next to the head portion 25 adapted to permit air to enter and pass into the head portion and also being connected to the space between the end wall 22 of the main body portion and tight contact. The head portion 25'has an outwardly extending portion 35 adjacent the enlar ed portion of the inlet connection 30 and tting it at 36 on the outer side of its opening 32 whereby the air may enter the header through an opening 32 in the head wall 26 corresponding to opening 32.

The outlet connection 37 for the main body portion of the air pump has an outwardly projectingportion 38 with a side opening 3. communicating with the air space in the header as in the case of the inlet pipe con nection, as indicated in Figure 3. The outlet is of course in direct connection with the corresponding'air space in the main body porthe rotor casing and corresponding openings 42 and 43 on that side of the partition 41 which receives theair from the inlet conncction and thus there are inlet openings for the rotor from the air spaces in both ends of the casing. There-are also corresponding openings 44 and 45 spaced around the circumfer- Jence a material distance from the other openings WhlCh are on that side of the partition 41 which is in open communication with the outlet connection 37 and therefore the air leaves the rotor through these openings on both sides.

The water pump housing 12 includes the main bod "portion 46 which includes the volute casing 47 and the impeller 48 and the wall of the impeller on the side next to the air pump and a circular projecting portion 49 having an end contact surface 50 circular in form and surrounding an enlarged central liiU opening in the end wall of the water pump housing. The contact surface 50 fits the cor connection 52 for water, as will be seen in Figure 4, and the outlet or discharge pipe connection 53 is also a part of this body portion of the housing. The head portion 54 of the water pump includes as a part of it the outer wall 55 of the impeller casing and also the end wall 56 constituting the end closure for the housing, the walls 55 and 56 being spaced apart a material distance. It will be seen by reference to Figure 4 that the inlet connection 52 of the main portion has a flat side wall 57 through which there is an opening 58 at the outer side of the volute casing and that the head portion has an outwardly exending portion 59 fitting the outer face of the part 57 and having an opening therein 60 corresponding to the opening 58 whereby the entering water may pass into the head portion on the outer side of the volute casing as well as on the inner side. 'The impeller 48 has a hub portion 62 mounted on the shaft 28 So as to rotate therewith its inner end abutting a shoulder 63 formed by the reduction in diameter of the shaft at that point and its outer end being held by a screw threaded nut 64 on shaft 28. Water enters the impeller on both sides of the casing at the hub. The end wall 56 of the head portion 54 has on its inner side an integral wall 65 which extends around the shaft 28 forming a chamber around the bearing connection in the end 56 and extending upwardly in the form of a channel or passageway 66 to the upper portion of the chamber in the head portion. The purpose of this is to guide any air which may leak into the housing through packing 67 in the end 56 to the upper part of the air pump so that it will not be drawn in by the, impeller. In order that any air which may accidentally enter the housing of the water pump and that which may be drawn into the housing with the entering water when the level 1n the tank is too low may escape from the housing, the main body portion is prov ded with apassageway 68 extending over the upper top portion of thevolute casing, as shown 1n Figure 3, and isconnected by opening 69 to the upper part of the chamber in head portion 54 and there isa vent opening 70 in 1ts upper portion adapted'to be connected to pipe 15 and convey the air to the tank 10.

- The chamber in'the body portion of the air pump housing between the end wall 22 and the end wall 23 of the rotor cas ng is on the inlet side of the pump and thus the 7 air in it during operation is always rarified due to the action of the rotor drawing it out creating a partial vacuum. The open-- ing 7 in the end wall 22 of the air pump is cylindrical in form and an integral sleeve is formed on the inner face of the Wall exabove stated, the air in the air pump at this point is under partial vacuum and will not pass into the water pump. Such water as passes through the opening will serve to furnish the supply for the air pump. The end of the drive shaft projecting beyond the end of the air pump is supported by a ball bearing 72 carried by a. bracket 73 which has a ring-like portion 74 fitting bearing surfaces on the end of the header portion 25 of the air pump housing and having longitudi nally inclined arms carrying at their outer ends a sleeve 75 which has the ball bearing within it. Collars 76 and 77 are secured to the sleeve 75 fitting its ends and having central openings through which the shaft passes the ball bearing belng between them. The inner raceway 78 of the ball bearing is heldin stationary position by a shoulder on the the end wall of the header portion ofthe water pump by bolts 83 through radially extending lugs'or projections, as shown in Figure 2. The bracket 73 is secured to the air pump head portion by similar means. The raceways of bearing 81 are in stationary position the inner raceway being held between a shoulder on the end of the shaft formed by a reduction in diameter of the outer portion and a screw threaded nut 84. The outer raceway is held in position by two ring nuts 85 having spaced holes 86 in their .outer sides for locking and turning. A cap 87 fits the inner face of the sleeve 88 which is carried by the bracket and has a central opening surrounding the shaft and a projecting pin' 93 entering one of the holes 86 in the ring nut to hold it in adjusted position and the ca'p89 constitutes a closure for the outer end of the sleeve across the end of the shaft,

and is provided with'a pin 94 entering a hole in the adjacent ring nut to hold it in fixed 'position. The

caps

87 and 89 when placed in position with their pins 93' and 94 in holes in the ring nuts 85 may be used to turn and'adjust those nuts. It will be noted that the roller bearing 81 is the only bearing in either casing'adapted to prevent longitu- 180 dinal movement of the shaft therein and thus a slight longitudinal movement of the shaft in the other bearings is permitted. As will be seen by reference to Figures 1, 3 and at the housing 17 and head portion of the air pump are detachably connected together by means of integral peripheral flanges 97 and 98 at their meeting ends provided with aligned radial slots 99 in which bolts 100 fit.

It will be noted that the shaft 28 varies in diameter having the largest diameter where it passes through the end wall 22 of the air pump and the arrangement is such that the different parts of the two pumps through which it passes may be brought to position over the ends of the shaft in proper succession. The brackets carrying the bearings may be removed from the shaft and from the head portion of the pump or may he removed with the head portions. It will be noted that the head portion 54: has a marginal flange 91 with a surface in a radial plane fitting a corresponding surface on the body portion 68 and may be detachably secured to the body portion by bolts 92 passing through this flange or by other means.

In assembling impeller 48 of water pump can be properly adjusted axially by means of the adjustable bearing 81. The shaft 28 is slid-able in the rotor of the air pump although keyed. to rotate therewith, and the bearing 7 5 permits axial movement of the shaft,'so the bearing 81 is the only means for adjusting the rotor of the water pump. Furthermorethe improved construction of this bearing is such that a very delicate axial adjustment of the water pump rotor may be obtained. For this purpose the cap screws 105 are removed and the

caps

87 and 89 turned carrying with them the rings 85. If, as shown, there are four cap screws for each cap the rings can be turned any multiple of a quarter turn. If a finer adjustment is required then the

pins

93 and 94 are inserted in different holes 86 after the rings have been adjusted.

The shaft 28 may be rotatively driven from any suitable source of power by any suitable means but a belt pulley 90 is shown for the purpose, it being attached to the outer end of the shaft beyond the air pump.

Although one specific embodiment of the invention has been shown for purposes of illustration, it -is to be understood that it is not limited to that particular form beyond what is indicated in the following claims.

Having thus describe-d the invention what is claimed as new and desired to be secured by Letters Patent is:

1. A combined unit for installation in a gas and liquid system which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said umps, means forremovably con'necting sai housings respectively to said system,

said housings being provided with mating surfaces whereby said housings may be re-' movably and directly secured together end to end, permitting the housings to be separated and another gas or liquid pump substituted, and a common shaft for both of said umps, whereby both of said pumps operate 1' t the same speed.

2. In a gas and liquid system, the combination of a rotary gas pump and a rotary liquid pump provided with separate housings removably and directly secured together end to end whereby they may be separated, a part of the end wall of one forming a corresponding part of the end wall of the other, a single drive shaftextending through them, and means for connecting said pumps to said system. v

3. A combined unit for installation in a gas and liquidsystem which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said pumps, means for removably connecting said housings respectively to said system, said housings being provided with mating surfaces whereby said housings may be removably and directly secured together end to end, permitting the housings to be separated and another gas or liquid pump substituted, a common shaft for both of said pumps, whereby both of said pumps operate at the same speed, and detachable brackets secured to the outer ends of said housings carrying anti-friction bearings for said shaft, said detachable brackets facilitating the said substitution of the pumps.

4. A combined unit for installation in a gasand liquid system which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said pumps,- means for removably connecting said housings respectively to said system, said housings being provided with mating surfaces whereby said housings may be removably and directly secured together end to end, permitting the housings to be separated and another gas or liquid pump substituted, a common shaft for both of said pumps, whereby both of saidpumps operate atthe same speed, and removable outer head portions for each of said housings permitting access to the interior of the main body portions.

5. A combined unit for installation in a gas and liquid system which requires gas and liquid to besinmltaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each-of said pumps, means-for removably connecting said housings respectivel to said system, said housings being provi ed with mating surfaces whereby said housings may ill) be removably and directly secured together end to end, permitting the housings to be separated and another gas or liquid pump substituted, a common shaft for both of said pumps, whereby both of said pumps operate at the same speed, and means attached to the main body portion of one of said pumps for supporting the unit in elevated fixed position.

6. A combined unit for installation in a gas and liquid system which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said pumps, means for removably connecting said housings respectively to said system, said housings being provided with mating surfaces whereby said housings may be removably and directly secured together end to end, permitting the housings to be separated and'another gas or liquid pump substituted, a common shaft for both of said pumps, whereby both of said pumps operate at the same speed, removable outer head portions for each of said housings permitting access to the interior of the main body portions, brackets detachably secured to the outer ends of said portions and bearings in said brackets for the projecting portions of the shaft.

7. A combined unit for installation in a gas and liquid system which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said pumps, means for removably connecting said housings respectively to said system, said housingsbeing provided with mating surfaces whereby said housings may be removably and directl secured together end to end, permitting the housings to be separated and another gas or liquid pump substituted, a common shaft'for both of said pumps, whereby both of said pumps operate at the same speed, brackets secured to said housings carrying bearings for said shaft, said shaft being so mounted in said gas pump housing and the bearing on the bracket attached to it so constructedas to permit slight relative longitudinal movement and the bearing on the bracket carried by the liquid pump housing being so connected to said shaft and the bracket as to prevent relative longitudinal movement.

8. Acombined unit for installation in a gas and liquid system which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of.

said pumps, meansfor removably connectingsaid housings respectively to said system, said housings being provided with mating surfaces whereby said housings may be removably and directly secured together end to end,permitting the housings to be separated and another said pumps operate at the same speed, detachable brackets at the outer ends of said housings having ring-like portions concentrically surrounding said shaft having contact surfaces fitting corresponding contact surfaces of said ends, inclined. spider arms connecting said ring-like portions to bearing sleeves for said shaft, and means for rigidly securing said brackets to said housings.

9. A combined unit for installation in a gas and liquid system which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said pumps, means for connecting said housings respectively to the said system, the facing ends of said housings being provided with corresponding contact surfaces adapted to closely fit each other making a tight joint,'means for rigidly securing said housings together with said surfaces in contact, and a single drive shaft extending through both. housings.

10. A combined unit for installation in a gas and liquid system which requires. gas and liquid to be simultaneously pumped, comprising. in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said pumps, means for connecting said housings .respectively to the said system, one end wall of said liquid pump housing having an enlarged central circular opening surrounded by a contact surface and said gas pump housing having at one end a contact surface closely tting that of the liquid pump housing, means for rigidly connecting said housings together end to end with said surfaces in contact, and a single drive shaft extending through both housings.

11. A device of the character described, comprising in combination'a rotary gas pump and a rotary liquid pump provided with separate housings, one end wall of said liquid pump housing having an enlarged central circular opening surrounded by a contact surface and said gas pump housing having at one end a contact surface closely fitting that of the liquid pump housing, means for rigidly connecting said housings together end to end with said surfaces in contact, and a single no I drive shaft extending through both housings,

the said contact end of the gas pump housing constituting a part of its inlet chamber whereby no air can pass into the liquid pump housing around the shaft thus rendering packing between said shaft and end unnecessary.

12. A device of the character described, comprising in combination a rotary as pump and a rotary liquid pump provided with separate housings secured with a watertight joint directly together end to end with the, inlet chamber of the gas, pump next to the liquid pump, a single drive shaft extending through said housings, bearings for said shaft carried by the outer ends of said housings on their outer sides, the openings in the outer end walls of said housings through which said shaft extends being provided with packing to prevent leakage and the corresponding opening in the intermediate wall between the housings being smooth and cylindrical without packing.

13. A device of the character described,

comprising in combination a rotary gas pump and a rotary liquid pump provided with separate housings, one end wall of said liquid pump housing having an enlarged central circular opening surrounded by a contact surface and said gas pump housing hav ng at one end a contact surface closely fittmg that of the liquid pump housing, means for rigidly connecting said housings together end to end with said surfaces in contact, and a single drive shaft extending through both housings, the said contact end of the gas pump housing constituting a part of its inlet chamber whereby no gas'can pass into the liquid pump housing around the shaft thus rendering packing between said shaft and end unnecessary, the outer end of the liquid pump housing having on its inner side an 1nwardly projecting wall forming a small chamber around the shaft and an upwardly extending passageway to guide any gas entering said housing around said shaft to the upper part of said housing and a vent opening at the top of said housing for the escape of said gas adapted to receive a discharge pipe.

14. A combined unit for installation in a gas and liquid system which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said pumps, means for connecting said housings respectively to the said system, each of said housings including a main body portion having inlet and discharge pipes connected thereto and enclosing the rotary member and a detachable head portionhaving integral therewith the outer side wall of the casing of the enclosed rotary member, means for detachably and rigidly securing said body portions to each other end to end, and means for detachably securing said head portions to' said body port-ions whereby access may be had to the rotary members without disconnecting or connecting pipes and whereby the pumps may be separated for substitution.

15. A combined unit for installation in a gas and liquidsystem which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said pumps, means for connecting said housings respectively to the said system, each of: said housings including a main body portion having inlet and discharge pipes connected thereto and enclosing the rotary memand enclosing her and a detachable head portion having integral therewith the outer side wall of the casing of the enclosed rotary member, means for detachably and rigidly securing said body portions to each other end to end and means for detachably securing said head portions to said body portions, brackets including ringlikq portions fitting contact surfaces on the outer faces of said head portions around said shaft, sleeves carrying bearings for said shaft, spider arms connecting said ring-like portions and sleeves and means for detachably connecting said brackets to said head portions.

16. A combined unit for installation in a gas and liquid system which requires gas and liquid to be simultaneously pumped, comprising in combination, a rotary gas pump, a rotary liquid pump, separate housings for each of said pumps, means for connecting said housings respectively to the said'system, a single drive shaft extending through them, each of said housings including a main body portion having inlet and discharge pipes connected thereto and enclosing the rotary member, and a detachable head portion havin integral therewith the outer side wall of the casing of the enclosed rotary member, the end wall of said body portion of the pump housing having an enlarged central circular opening surrounded by a projecting cont-act surface fitting a contact surface on the end of the body portion of the other pump housing and detachable means for rigidly connecting said portions with said surfaces in contact and means for detachably securing said head portions to said body portions whereby access may be had to the rotary members without disconnecting or connecting pipes and whereby the pumps may be sepa- 5 rated for substitution.

17. A rotary water pump comprising a housing including a main body portion having the inlet and discharge pipe connections the rotary member, and-a detachable hea portion having integral therewith the adjacent side wall of the casing of the rotary member but spaced therefrom forming a chamber between them, a drive shaft extending through said housing, means for detachably securing said head portion to said body portion, said head portion having on its inner side an inwardly projecting wall forming a small chamber around the shaft .and an upwardly extending passageway therefrom to guide any air entering around said shaft to the upper part of said housing and an air vent pipe connecting at the top of said housing, and a chamber on the other side of said rotary member also in communication with said vent pipe;

18. In combination, a liquid pump constituting one of'a series graduated in capacity, a gas pump constituting one of a. similar series of gas pumps, said liquid pump and said gas pump each having an housing constructed so that either may be secured to an-- other of the opposite series to thereb form a single unit consisting of a combine liquid and gas pump. e

19. In combination, a liquid pump constituting one of a series graduated in capacity, a gas pump constituting one of a similar series of gas pumps, said liquid pump having a housing provided with a contact surface common to its series, and said gas pump having a housing provided with amating surface common to its series, whereby either may be secured to another of the opposite series to thereby form a-single unit consisting of a combined liquid and gas pump.

20. In combination, a liquid pump having a housing and an impeller therein constituting one ,of a series graduated in capacity, a gas pump having a housing and a rotor therein constituting one ofa similar series of rotors, and a common shaft for said impeller and rotor, said impeller being provided with of the opposite series to thereby form a single unit consisting of a combined liquid and gas a 21. In combination, a gas pump anda liquid pump having separate housings, said liquid pump housing having an openin surrounded by a contact surface and said gas pump housing having a mating contact surface and a common drive shaft extending through said opening, the contact part of the gas pum housing constituting part of its inlet chain er whereby no air can pass into the liquid pump housing around the shaft,

thus rendering packing between said shaft and end unnecessary.

In testimony whereof I hereunto afiix my signature.

ravine oanumues.