US2496668A - Nutating axis rotary compressor - Google Patents

Description

Feb. 7, 1950 D. OQMANSEAU 2,

NUTATING AXIS ROTARY COMPRESSOR Filed Feb. 18, 1946 3 Sheets-Sheet l IN V EN TOR.

Patented Feb. 7, 1950 UNITED STATES fATENT OFFICE was nn'rsrmo AXIS ao'rsar COMPRESSOR.

David 0. Manscau, Berkley, Mich.

Application February 18, 1946, Serial No. 648,331

1 Claims. (Cl. 230-139) This invention relates to fluid pumps or compressors, and more particularly to an improved and simplified device having a minimum number of moving parts and designed to provide a substantially balanced structure in which inertia stresses, vibration, and noise are minimized.

The invention is designed to provide a light weight positive displacement pump capable of functioning to produce either positive fluid pressure or vacuum and wherein low operating stresses are involved. Pumps 01' this character are required in many industrial applications such for example as to compress gaseous refrigerant to convert it to the liquid formin refrigerators of the domestic type, to develop positive fluid pressure or vacuum for operating the brakes of vehicles, and for many other purposes. a

An object of this invention is to provide an improved motor compressor unit, having a minimum number of moving parts, to provide a source of fluid pressure.

A further object of the invention is to provide a motor compressor unit havinga single rotatable element which functions both as the rotor of an electric motor and as the driving element of the compressor unit.

Yet another object of the invention is to provide an improved compressor wherein the ratio of capacity to weight is a maximum.

Yet another object of the invention resides in the provision of a slotted stationary member having abutments oscillatably mounted therein and contacting a gyratory impeller member to form pump chambers for compressing fluid.

Another object of the invention is to provide a fluid compressor having a generally hemispherical impeller designed to gyrate about the geometric center of the sphere in a spherical bearing to produce an improved fluid compressor.

Another object of the invention is to provide a light weight motor compressor unit which is economical to manufacture and eflicient in operation.

Further objects and advantages of the invention will be apparent from the following detailed description, considered in connection with the accompanyingdrawings, submitted for purposes of illustration only and not intended to define the scope of the invention, reference being had for that purpose to the subloined claims.

In the drawings, wherein similar reference characters refer to similar parts through the several views:

Fig. 1 is a vertical sectional viewof a motor compressor unit embodying the present invention;

Fig. 2 is an enlarged view in elevation of the movable abutment;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary sectional view taken substantially on the line 4-4 of Fig. 1 but showing the impeller and valve block in elevation rather than in section;

Fig. 5 is a fragmentary sectional view similar to Fig. 4, but showing the impeller and valve block in section; and

Fig. 6 is a view in perspective of the movable abutment and its associated parts.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of being embodied in other forms and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring now to the drawings, it will be observed that the motor compressor unit includes a base member ID to which is secured in gastight relation as by welding a dome or shell l2, to

form a reservoir for the compressed fluid, as well as to constitute an enclosure for the motor-compressor unit now to be described.

The base III is formed with an upwardly extending casing is upon which is mounted a motor housing. The motor housing comprises a lower projection I6 having horizontal flanges secured to similar flanges on the casing i l by bolts l8, a horizontal circular portion provided with vertical cylindrical flange 20 nested within the shell l2, and an axial bearing 22 forming a journal for the rotor of the electric motor, hereinafter described.

The upper portion of the bore of the casing l4, and the lower portion of the bore of the projection It, are machined to spherical contour as shown at 23 in Fig. 4, the remainder of the bore in each case being cylindrical. The spherical surfaces together form a zone of a sphere, which serves as a bearing for a hemispherical impeller 24, designed to gyrate about its own geometric center 25 in a manner, and for a purpose, hereinafter more fully described.

Within the cylindrical bore of the casing I4 is seated a stationary pad or valve block 26, generally cylindrical in form, but havingits upper end machined to fit snugly within the spherical zone above described, and with its upper surtwo symmetrical halves 28a and 28b, which are:

separated from each other by a slot II. The

central semi-cylindrical bore in which is mounted a pin 13 havingan approximately hemispherical l head 35. The head SI and the upper portion of the pin a are formed with a slot 31 which lies in the plane of slot ff. The head it is seated in a hemispherical recess in the impeller 24. An abutment s4 is mounted for rocking movement within the slots 32, 31, and is provided with a bearing aperture 8' (Fig. 2) which registers with a corresponding bearing aperture it in the head 1!. In these bearing apertures is a bearing pin is which is designed to form a pivot upon which the abutment 34 oscillates in synchronism with the impeller 24, to prevent flow of fluid from one side to the other of the abutment. The respective ends of the abutment thereby constitute walls of the pumping chambers. The pin 38 is located at the geometric center ll of the impeller 2|, and the upper edge ll of the abutment extends substantially diametrically of the sphere and is rounded to flt into a semi-cylindrical groove extending diametrically of the impeller 24, to prevent rotation of the impeller relative to the abutment, and to prevent leakage of fluid from one side to the other of the abutment, while permitting a rocking motion of the impeller upon the edge ll. The outer edges 42 of the abutment are of circular contour as viewed in elevation in Fig. 2, and are also of circular contour as viewed in cross section, to conform to the spherical bearing surface 23. In oscillating about the pin ll, the respective ends of the abutment will alternately move downwardly into the slot 32, the slot beneath the path of the abutment being occupied by spacingblocks 44 which are arranged one on each side of the pin 83.

The electric motor which drives the compressor comprises a stator ll flxedly mounted within the cylindrical flange 20. and a rotor 48 having an impeller shaft ll iournaled in the bearing 22 in driving relation to the rotor. The shaft terminates at its lower end in,a disk-shaped head If, having-a cylindrical outer surface rotatably seated within the cylindrical bore of the proiection is, which forms a Journal therefor, the uppermost point of theimpeller 24 being in contact with the head s2.

- half-blocks 28a and "b are grooved to form a-- various moving parts of the compressor.

' arouse f 4 verticalbcresll," formedintheblockil. At their upper ends. bores I! and ii are provided I with check valves I. Beyond the check valves thebores so, If terminateinports 1|, 1| inthe frusto-conical surface ll of the block II. The portsareformedsspartoftheslotsl,andconstitute the inlet ports to the pumping chambers. Similar ports 12, the outlet ports from the pump cham lead through check valves I4, II and branches IL-ll to an outlet duct II which terminates inthoupperportion ofthe shell is above the oil level. A fluid outlet conduitsiismountedinthetopoftheshell l2,and is provided with a suitable strainer 04 to separate liquid particles'or other non-gaseous matter from the fluid being compre-ed. If the unit is used in refrigeration mechanism to compress gaseous refrigerant and convert it to liquid, the outlet will be connected to a refrigerant condenser to transmit compre-ed gaseous refrigerant thereto, whereas the inlet duct 02 will be connected to the header of a refrigerant evapa'ator to withdraw gaseous refrigerant therefrom. The check valves ll, 14 and II are preferably formed of hard rubber or other similar material, andactasacoustic mufliersbypermitting the gas being pumped to change its volume, any sound created by the operation of the parts being dissipated by the block 20 and the surrounding oil.

Thespacewithintheshell iiisfllledwithlubricating oil to a level below that of the lower edge of stator l0. Oil may therefore flow inwardly through oil hole I! to the upper surface of the impeller 24 whence it is distributed to the The pressureincasing II forcestheoilthroughthe hole to provide increased oiling when said pressureishigh. Ixcessoilispumpedout through the outlet duct II. An additional oil hole I! admits lubricant to the upper surface of head II, where it is picked up by spiral lubricating grooves as on the upper surface of head If, whence it will be entrained in a helical groove ll formed on the outer surface of shaft II, and thence carried upwardly to overflow at the upper end of the bearing 22. By this means a continuous flow of lubricant from the shell I! through the moving parts of the mechanism is maintained. Aplug l2 isseatedinthebase iltoallow withdrawal and replenishing of the lubri- With the parts in the positions shown in the drawings, the space between the impeller 14 and u the conical surface I. is divided by the abutment I into two pumping compartments, equal to each other in horizontal proiection and cubic volume, andindicatedinPig.3-.tl4and OI. Assuming the motor to rotate in the clockwise direction, ro-

10 tation of the shaft is will act through stud l4 Ito'impart motion to the impeller 24, causing it to mate about its geometric center Ii, and causing the radial line of contact between surfaces" and" tomoveintheclockwisedirectionfroma 45 linewhichcoincideswiththelefthalfoftheslot I! as viewed in Pig. 3, to a position displaced clockwise therefrom. In so doing, the line of contact will pass over the inlet port II, and will divide the compartment .4 into two pumping chambers, the chamber to the left of said line being of increasing volume, while the chamber to the right of said line will be of decreasing volume. Fluid will thus be drawn into the chamber at the ieftofthelinethroughinletportll,andwillbe communicate, through suitable couplings, with 75 expelled from the chamber at the right of said line through the port it. The compartment be-- low slot II in Fig. 3 will not vary greatly in volume during this. operation. a

When the electric motor is energized, therefore, the head will be rotated and will act through stud 54 to cause gyration of the impeller 24 about its geometric center, the anglethrough which the working surface of the impeller gyrates being equal to twice the angle between the stud I4 and the axis 58. The surface so will in such gyration define a cone with its apex at the geometric center 25 of the impeller, and the surface 28 of the stationary member lies in that cone.

Operation of the compressor will therefore act to draw fiuid through the inlet 62 and branch 63, bore 66 and port 10 to the chamber of increasing volume, and will force fluid out from the chamber of decreasing volume through port 13, bore I5 and branch 11 to the outlet duct II, where it will increase the fluid pressure within the shell l2. These conditions will obtain until the radial line of contact has passed the right half of slot 32, whereupon the line will define two respectively enlarging and diminishing chambers is within the compartment 06, causing fiuid to be drawn in by suction through the inlet port H and forced out by pressure through the outlet port I2,

in a manner corresponding to that above described. The check valves prevent any retrograde now of fluid.

=N0 upper bearing for the rotor 48 of the electric motor is needed, because the stator 46 is concentrically disposed within the flange 20, and the bearing 22 is vertically extended to give a sub- I stantial bearing area to the shaft 50.

It will be apparent that if desired another fluid pump or compressor element may be positioned at the opposite end of the shaft 50 to provide aseparate fluid pressure generator operating in parallel with the generator just describedgor if desired one of the compressors may be connected in, series with the other't'o receive compressed fiuid therefrom and-further compress it.

The impeller 24 may. be formed in any suit- 7 able mariner, it being contemplated that. for H economy of manufacture it may be made of powdered metal compressed and sintered to provide a solid homogeneous structure. By nature of its design, the impeller is inherently balanced,

both statically and dynamically.

: t il b apparent that the instan device may 1 Although the invention-has been described with particular reference to 'aflspecificembodiment, it may bemodifiedwithiri the skill 'of artisans in this art,an'd is thereforenotto be considered aslimite'd in scope ex'cept by-the. terminology of the following claims T 1 1 ment contacting a groove in said plane surface. said slot being grooved to form inlet and outlet ports communicating with said chambers contiguous to the abutment, and an electric motor having its rotor connected to said impeller in driving relation thereto.

2. A motor compressor unit comprising a housing having a part-spherical inner surface, a hemispherical impeller mounted in said housing for gyration about its geometric center, said impeller having a plane equatorial surface which in such gyration defines a cone, a groove in said surface, a member having a conical surface coinciding with said cone and having a diametrai slot, 9. pin in said slot having a spherical head, an abutment mounted'insaid pin for oscillation in said slot about said geometric center and having an edge contacting said groove to form with the impeller and said member and housing and head a compression chamber, and an inlet and an outlet for said compression chamber.

3. A motor compressor unit comprising a housing having a part spherical inner surface, a hemispherical impeller mounted in said housing for gyration about its geometric center, said impeller having a plane surface which in such gyration defines a cone, a groove in said surface, a member having a conical surface coinciding with said-cone and having a diametric slot, a pin in said slot having a spherical head, an abutment mounted in-said pin for oscillationin said slot about said geometric center, said abutment hav ing a rectilinear edge contacting said groove in fluidtight relation and forming with the impeller and said member and housing and head a compression chamber, and an inlet and an outlet for said compression chamber.

4. A compressor comprising a housing having a part-spherical inner surface, a hemispherical impeller in said housing, drive means for causing said impeller to gyrate about its geometric center, said impeller having a plane surface whichin such gyration defines a cone, a groove in said plane surface, a member having a conical l. A motor compressorunit comprising .meansforming a part-spherical chamber, a stationary member having a conicalsurface' projecting into said chamber, a diametral' abutment mounted for oscillation in a slot in said stationary mem- -ber,- a part-spherical" impeller in said chamber ing and head a compression chamber, and an inlet" and an outlet for said compression chamber. l I, 1

5. The invention definedin claim 4, comprising in, addition a fluidstight container enclosing the mechanism and forming a reservoir for lubricant .and an accumulator for fluid compressed by the compressor. v 7

- 6. The invention defined in claim 4, compris ing} inaddition rotary driving 'means :-for' the compressor, and-means associated with said driving means for: circulating lubricant in contact with the moving partsof the compressor,

7. The invention definedin claim- 4, compris- "m in addition a fluid-tight conta inerfor said compressor-, -a 'fiuid conduit leading from the ex terior .of said container .to the compressor, and a second fluid conduit leading from the to the interior of the container;

I navm'o. memo. (l!efes-encssonfoliowingpagc) 7 8 REFERENCES mm mm M pm The winl references are of record in the g 1:: file of this P tent. 3m mm "nu-"- m, 1, 1m an I! roman mm 3% Tab e? Dec :1 1m numb nm mu-u- 30 Gmt Brltfln July 1'. 1, 958-408 mow my 11, mo m mm m a 1 1,638,133 31 8 1 Au. 9, 1927 an) G? z" "a 3 Vincent 0c; 1, 1935 I. 09ml 2,101,051 Cuny Doc. 7. 1m

Images