US1915097A

US1915097A - Rotary pump

Info

Publication number: US1915097A
Application number: US322227A
Authority: US
Inventors: Ralph E King
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1928-11-27
Filing date: 1928-11-27
Publication date: 1933-06-20
Anticipated expiration: 1950-06-20

Description

R. E. KING ROTARY PUMP June 20, 1933.

Filed Nov. 27, 1928 2 Sheets-Sheet l OOOGOGOOGOGOm/UOGOO HI n ll, 5

Inventor' RcLLph E. K'Lng @1MM HLS Attorney.

June 20, 1933. R E K1N@ 1,915,097

ROTARY PUMP Filed Nov. 27, 1928 2 Sheets-Sheet 2 PLQ; g, PLS. 5. 45 44 47 26 @1% 24 ,27 72 Y YI" 66 70 VK i HLS ttoPne-H.

Patented June 20, 1933 UNITED STATES PATENT OFFICE RALPH E. KING, OF FORT WAYNE, INDIANA, .ASSIGNOR T GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK ROTARY PUMP Application led November 27, 1928. Serial No. 322,227.'

My invention relates to rotary pumps of the type including a body having a chamber with a displacement member loosely fitted therein.

In pumps of'this kind, as heretofore constructed it has been the practice to actuate the displacement member by a shaft extending through the pump body. This complicated ,the construction of the pump and also necessitated the use of packing glands on the shaft which were difficult to maintain Huidtight without excessive friction. Moreover, diiiiculty has been experienced with these pumps in lubricating the moving parts and also in obtaining good volumetric efficiency on account of leakage between the displacement member and the walls of the pump chamber.

An object of my invention is to provide a simplified rotary pump construction in which the number of working parts is minimized, in which packing glands are not required, and which involves little or no unbalanced mass in its construction, so that vibration and wear will be reduced as compared with prior constructions.A I accomplish this by providing a. pump including a body having a chamber, a displacement member smaller than said chamber arranged therein in contact with the wall thereof, and an arrangement for rotatably supporting the pump body and the diS- placement member on axes eccentric with respect to each' other so as to move the displacement member and the pump body with respect to cach other and to produce a pump` ing action.

Another object of my invention is to "provide an improved arrangement for lubricating the bearings and other working surfaces of the pump and to supply oil or the like under pressure between the contacting surfaces of the wall of the pump chamber and the dis placement member therein so as to seal the pump and improve the volumetric efiiciency thereof.

A further object of my invention is to provide a simplified arrangement for unloading the pump during a predetermined variation in speed of rotation thereof, so that the motor 510 or other device used to drive the pump will not be loaded to any substantial extent until it reaches a predetermined speed.

Further objects and advantages of my invention will become .apparent as the following description roceeds, and the features of novelty which c aracterize my invention will be pointed out with particularity in the claims annexed-to and forming a part of this specification.

In the drawings Fig. 1 is a perspective 60 View of a compression refrigerating machine including a pump embodying my invention, the machine being partly broken away to more clearly illustrate the constructign; Fig.

2 is a transverse section'on the line 2-2 of 65 Fig. 1 showing the displacement member of the pump in mid-position in which the intake and compression spaces are equal; Fig. 3 is a view similar to Fig. 2 showing the displacement member in the position in ,which the compression space is substantially a minimum andthe intake space is substantially a maximum; Fig. ,a is a view similar to Fig. 2 showing the displacement member in the position in which the intake space is substantially a minimum and the compression space substantially a maximum, and Fig. 5 is a perspective view of the moving parts of the pump,

in section, or partly broken away.

Referring to the drawings I haveI shown the pump embodyingmy invention in connection with a compression refrigerating machine arranged on a cabinet 10 which comprises a cooling unit 11 in the cabinet, a condenser 12 supported on anv air-tight casing S5 13 secured to the base member 14:.v The driving motor 15, which isconnected to an eX- ternal circuit by conductors, one of which is shown at 16, and the pufmp of the machine are resiliently supported on the base member 14 by springs 17 so as to prevent noise and vibration being transmitted from the motor and pump through the walls of the casing 13. In this construction evaporated refrigerant is supplied from the cooling unit 11 to the intake` 18 of the pumpI through a pipe 19. vThe refrigerant is compressed and discharged through a port 20 into the casing 13 and then passes into the intake 21 of the condenser. The refrigerant is cooled and Y.the desired refrigerating el'ect on the cooling unit 11, as will be readily apparent to those skilled in the art;

In accordance with 1n invention, the pump which I emplo in thls machine for compressinglthe re rigerant includes a body havmg a c amber and a displacement member smaller than the chamber and arranged therein in contact with thek wall thereof, `and an arrangement for rotatably supporting the body and the displacement member on axesf eccentric with respect to each other so as' to move the displacement member and the body with respect to each other and to produce a pumping action. The pumping action is caused by the movement of the periphery` of the body with respect to the point of contact between the body and the displacement member, as will be hereinafter more fully exlained. The pump may be of any suitable orm, but I prefer to construct the pump as shown in the drawin This construction includes a body 24 havmg a cylindricalchamber 25 therein which is open at one end and a shaft 26 formed integral with the body and coaxial with the chamber 25, which is connected to the motor 15 for driving .the pump. A cylindrical displacement member 27 is arranged in the pump chamber with the end 28 thereof in engagement with the end wall 29 of the chamber, and is formed with a portion or flange having a surface 30 presented toward the end wall of the chamber and engaging the body 24 about the open end of the chamber 25. The displacement member is of smaller'diameter than the chamber 25, and is formed so that the end 28 thereof and the flange 30 are both retained in engagement respectively with the end wall 29 and the end 31 of the body 24 about the open end of the chamber 25, so as to provide a compression space between the displacement member and the body. The displacement member 27 is also provided with an integral shaft 32 coaxial therewith. The

shafts

26 and 32 are supported in bearings 33 and 34 respectively which are eccentric with respect to each other and arranged so that a portion of the periphery of the displacement member 27 is in close contact with a portionl of the periphery of the wall of the chamber 25, as clearly shown in Figs. 2, 3 and 4.

The bearing 33 is secured in a central bore of the frame 35 on which the motor 15 is supported, and the bearing 34 is supported eccentrically with respect to the bearing 33 in a housing 36,A which is secured to the frame 35 by bolts 37. The lower end of the shaft 32 is su ported on a thrust bearing 38 which is bo ted to the pump housing 36, and inlet ports 39 of the pump, which are formed in the displacement member 27 (Figs. 2 to 5),

18 of the pump throu h assa es 40 and 41,

g dP g a surge chamber 42, an inwardly openin check valve 43. The discharge ort 44 o th pum is formed in the perip eral wall of the c amber 25, and is provided with an outwardly opening'eheck valve 45.

In order to render the displacement member 27 operative to pump fluid, I provide means extending between the displacement member 27 of the chamber 25 which divides thespace between them into intake and

compression spaces

47 and 48. In the construction illustrated I prefer to do this by arranging a blade 49 to slidably fit a slot 50 formed in the displacement member 27, which is arranged between the intake port 39 and the discharge port 44 of the pump. The outer end of the blade is formed with a rounded enlargement 51, which is adapted to closely fit into a socket 52 formed in the peripheral wall of the body 24 and extending axially thereof so that the blade can swing in'the socket 52 to permit the angular movement of the blade 49 necessary during the operation of the L2:

pump, when the displacement member swings back and forth from theposition shown in Fig. 3 to that shown in Fig. 4. The blade is also slidably fitted between the flange 30 and the end wall 29 of the chamber 25 so that it effectively prevents the direct flow of fluid in the pump from the.compres l sion space 47 to the intake space 48. The blade 49, however, not only serves to separate the space between the displacement greatly simplified over prior constructions,

and that the only moving parts are the rotatable body 24` the rotatable displacement member 27 and the blade 49. As the body 24 is rotatable about an axis substantially on the center of gravity thereof, and the displacement member 27 is also rotatable about an axis substantially on its center of gravity, the only unbalanced weight in the pump is the portion of the blade 49 extending between the outer periphery of the displacement meinber and the periphery of the chamber 25. As a result the unbalanced rotating mass of the pump is so small that there is little or no vibration during its operation.

During the operation of the pump structure which I have described, the rotation of the pump body 24 and the displacement member 27, in the direction indicated by the arrow in Fig. 2 about axes eccentric with respect to each other, causes their peripheries to move with respect to the point of contact between them which remains stationary with respect to the housing of the pump, as shown in Figs. 2 to 4. In Fig. 4 the pump is shown at the beginning of its intake movement.

.During substantially the first 180 degrees of movement of the pump from this position to that shown inFig. 3 the intake space 48 gradually increases because the intake ports 39 of the pump move clockwise about the periphery of the pump chamber with respect to the point of contact between the displacement member and the wall of the pump chamber. Further rotation of the ypump causes the intake ports'to pass the point of contact between the displacement member and the periphery of the pump chamber cuts off the fluid in the compression space47 from the intake ports. Continued rotation of the pump then compresses the fluid in the space 47 against the blade 49 and discharges the .same throughl the outwardly opening check valve 45. This cycle of operation is continually repeated during the operation of the pump so as to draw fluid through the inwardly opening check valve 43 and discharge the same through the outwardly opening check valve 45. l

If good volumetric efficiency is to be obtained in a pump of this kind, it is necessary to effectively seal the surfaces of the displacement member and the pump body in contact with each other to prevent leakage of the fluid being pumped therebetween, and I do this by supplying oil under pressure between these surfaces. In the particular construction illustrated, therefore, I form an oil groove 53 in the end 31 of the body 24 extending about the open end of the chamber 25 and supply oil thereto through

passages

54 and 55 from an oil pocket 56 above the bearing 33. I also form an oil groove 57 on the upper end 28 of the displacement member 27 for maintaining an oil film between the end of the displacement memberand the end wall of the chamber 25 and supply oil to this groove through a passage 58 communicating with the oil groove 59 formed in the shaft 32 and in the bearing 34 which supports the shaft 32. I prefer to supply oil under pressure to the oil grooves 53 and 57, and this may 64 be done in any convenient manner.

In pump constructions of this kind heretofore proposed oil has been supplied to the pump bearings by an auxiliary pump. This adds considerably to the cost of the pump and is often inconvenient and clumsy. I have found that an auxiliary pump can be embod1ed in the pump construction Without the necessity of a separate pump construction, wh1ch can be used for supplying lubricating oil to the bearings and to the wearing surfaces of thepump, or for any other desired purpose. In accordance with my invention, therefore, I utilize the means extending between the displacement member 27 and the pump body 24 to provide an auxiliary pump. During the operation of the pump the rotation of the body 24 and the displacement member about their axes, which are eccentric w1th respect to each other, causes the blade 49 to reciprocate in the slot 50. As the blade 49 closely fits the slot and the end of the displacement member 27 is seated against the end wall 29 of the chamber 25, a suitable compression space is formed between the end of the blade 49 and the walls of the slot 50.` In order to utilize the reciprocatory movement of the blade 49 for pumping, I provide suitable inlet and discharge ports. I do this in the present construction by providing a smglepassage 60 which extends from a point adjacent the outer periphery of the end of the shaft 32 to the slot through which fluid is drawn into slot when the blade 49 is moved outwardly therein, and through which fluid is discharged when the blade 49 is moved toward the axis of the displacement member. The flow of fluid in the desired time relation of the movement of the blade in the slot is controlled by an arcuate valve port 61 formed in the flat surface of the thrust bearing 38,

which communicates with the'intake pipe 62, and an arcuate discharge port 63 formed in the surface of the thrust bearing which communicates with a discharge port 64. The

arcuate ports

61 and 63 are arranged the same radial distance from the center line of the shaft 32 as passage 60 so that the intake and discharge fluid therefroln is controlled by these ports. Moreover, the angular relation of the

ports

61 and 63 to the blade 49 are such that the port 61 affords communication between the passage and intake pipe 62 during substantially the entire range of movement of the blade 49 outwardly from the axis of the displacement member, and the port 63 affords communication between the passage 60 and the discharge port 64 substantially throughout the entire range of movement of the blade 49 toward the axis of the displacement member. By this arrangement I utilize reciprocatory movement of the blade 49 for drawing fluid through the intake passage 62 and discharging it through the port In the construction illustrated I prefer to extend the intake pipe 62 into the body of oil 65 in the base member 14 and arrange a strainer 62a thereon through which oil is supplied to the intake pipe and utilize the pumping action of the blade 49 for supplying lubricating oil under pressure to the wearing surfaces of the pump. I lubricate the socket 52 of the blade 49 by providing an oil duct 66 extending from the end of the blade therethrough to the socket, as clearly shown in Figs. 2, 3 and 4. In order to supply oil under pressure to the bearings 33 and 34 and the oil grooves 53 and 57, I provide passages 67 and 68 extending from the discharge passage 64 to the oil pockets 56 and 69 of the bearings 33 and 34 respectively. Oil is supplied under pressure from the oil pocket 56 to the oil groove 53 in the body 24 through a passage 54, and oil is supplied from the oil pocket 69 to the oil groove 57 in the end of the displacement member 27 through passage 58. By this construction all of the wearing surfaces of the pump are thoroughly lubricated by oil under pressure so that frictional resistance in the bearings 33 and 34 is minimized and the sealing action of the oil film maintained between the displacement member and the body of the pump greatly improves the volumetric eflciency thereof. y

lVhen the motor 15 is started, if the pump is required to compress fluid during the period in which the motor comes up to normal speed, the load on the motor will be excessively high so that stalling or vibration results, I therefore provide a centrifugally responsive arrangement for rendering the pump inoperative to pump fluid until a predetermined speed of rotation thereof. In the construct-ion illustrated I do lthis by providing a port 7 0 communicating with the pump chamber adjacent intake port 39. The port 7 0 communicates with the high pressure side of the pump through an enlarged transverse bore 71 in the body of the pump, and a valve 73 is arranged in the bore 7l for controlling the port 70. In this construction as long as the port is open fluid will be bypassed between the intake and compression sides of the pump, so that no fluid will be compressed thereby. In order to render the pump operative at a predetermined speed of rotation thereof, I arrange an enlarged body 74 of the valve 7 3 eccent-rically with respect to the axis of rotation of the body 24. The enlarged portion 74 of the valve is provided with longitudinal ribs 75 for centering the valve with respect to the port 70, and for permitting fluid to flow freely between the port 70 and the passage 72. The enlarged portion 74 of the valve is arranged eccentrically"`with respect to the axis of rotation of the body 24 of the pump'and is normally retained in this position so that the valve 73 is out of engagement with the port 70 by a spring 76 secured to the enlarged portion 74 and to a plug 77 which is threaded into the end of the port 71. The tension of the spring 76 is such that the valve 73 does not move outwardly into engagement with the port 70 to close the by-pass and render the pump operative until the pump has attained a predetermined speed whicli is preferably substantially the normal running speed 0f the motor '15. In this Way thc starting load onthe motor is maintained within reasonable limits', and the vibration of the mechanism which would be likely to result from starting the pump suddenly under load is avoided.

Modifications of the rotary pump construction which I have described will occur to those skilled in the art, so that I do not desire my invention to be limited to the particular arrangement disclosed, and I intend in the appended claims to cover all modifications thereof which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

l. A. pump including a body having a chamber, a displacement member in said chamber having a slot, a blade arranged in said slot, means for actuating said displacement member to pumpfluid and for reciprocating said blade in said slot, said displacement mclnber having a single port communieating with said slot, and means actuated by said displacement member for controlling said port so as to utilize the reciprocatory movement of said blade for pumping fluidi.

2. A pump including a body having a chamber, a displacement member in said chamber having a slot, a blade arranged in said slot, means for actuating said displacement member to pump fluid and for reciproeating said blade in said slot, said displacement member having a single port communieating with said slot, means for supplying oil to said p0rt,'and for supplying oil therefrom to lubricate said pump, and means actuated by said displacement member for controlling said port so as to utilize the reciprocatory movement of said blade for pumping oil to lubricate said pump.

3. A pump including a body having a chamber open at one end', a displacement member smaller than said chamber and arranged therein in contact with the side wall thereof, said displacement member engaging the end wall of said chamber and having a surface presented toward the end wall of said chamber and engaging the open end of said body, means extending between the Wall of said chamber and said displacement member for separating the space between them into intake and compression spaces, means including said last-mentioned means for supplying oil under pressure between the surfaces of said body and said displacement member in contact with each other to seal the pump, and means for moving said displacement member about in contact with the llO side wall of said chamber to produce a pumping action.

4. A pump including a body having a cylindrical chamber open at one end, a cylindrical displacement member of smaller diameter than said chamber and arranged therein `in contact with the side wall thereof, said displacement member engaging the endwall of said chamber and having a surface presented toward the end wall of said chamber and engaging the open end of said body, means extending between the wall of said chamber and said displacement member for separating the space between them into intake and compression spaces, means including said last mentioned means for supplying oil under pressure between the surfaces of said body and said displacement member in contact with each other to seal the pump and means for moving said displacement member about in contact with the side wall of said chamber to produce a pumping action.

5. A pump including a body having a chamber, a displacementmember smaller' than said chamber and arranged therein in vcontact with the wall thereof, means extending between then wall of said chamber and said displacement member for separating the space between them into intake and compression spaces and for mechanically connecting ranged therein in contact with the side wall thereof, said displacement member engaging said body about the open end of said cham- 1 ber, means extending between the wall of said chamber and said displacement member for separating the space between them intoiintake and compression spaces, means including said last mentioned means for supplying oil under pressure between the surfaces of said body and said displacement member in contact with each other to seal the pump, means for moving said displacement member in contact with the side wall of said chamber to produce a pumping action, said body having a port communicating with said chamber for rendering said pump inoperative, a valve for closing said port to render the pump operative, and means for causing said valve to close said port at a predetermined speed of rotation of said body.

In Witness whereof, I have hereunto set my hand this 23d day of Nov., 1928.

RALPH E. KING.

chamber open at one end, a displacement member smaller than said chamber and arranged therein in contact with the side Wall thereof, said displacement member engaging the end wall of said chamber and having a surface presented toward the end Wall of said chamber and engaging the open end of said body, means extending between the wall of said chamber and said displacement member for separating the space between them into intake and compression s aces, means including said last mentione 4means for suplying oil under pressure between the suraces of said body and said displacement member in contactI with each other to seal the pump, means for movingsaid displacement pum fluid during a predetermined range of spee of rotation of 'said body.

7. A pump including a bod having a l chamber open -at one end, s; isplacement member lsmaller than said chamber and ar-