US2153371A

US2153371A - Refrigerating apparatus

Info

Publication number: US2153371A
Application number: US51760A
Authority: US
Inventors: Earl F Hubacker
Original assignee: Borg Warner Corp
Current assignee: Borg Warner Corp
Priority date: 1935-11-27
Filing date: 1935-11-27
Publication date: 1939-04-04
Anticipated expiration: 1956-04-04

Description

pr 49 1939 E. F. HUBAQKER l 29153937 REFRIGERATING PPARATUS 4 A l Filed Nov. 27, 1955 2 sheetsheet 2 INVENTOR.

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Patented Apr. 4, 1939 REFRIGERATIN G APPARATUS Earl F."Hubacker, Highland Park, Mich., assignorto'Borg-Warner Corporation, a corporation of Illinois Application November 21, 1935, serial No. 51,760

15 Claims.

This invention relates to refrigerating apparatus and has reference to an improved form of compressor construction which is particularly adapted'for use in refrigerating systems of the type wherein a refrigerating medium is circulated through a closed system and is successively compressed in a gaseous state, condensed into a liquid and thence expanded by evaporation at a relatively low pressure.

'Ihe compressor is of the type illustrated in Letters Patent No. 2,028,824, i'lled October 9, 1933,

A principal obj'ect of the invention thereof is I to provide an improved form of rotary compresser construction which is more quiet in operation, and in which, the tendency of certain of the parts thereof to Wear has been minimized.

Another object of the invention is to provide an 30 Another object of the invention is 'to provide a novel form of blade construction for compressors of the type herein disclosed.

Other objects and advantages will be apparent from a consideration of the following specification taken in conjunctionwith the accompanying drawings of which there are 2 sheets; and in 40 which: 4

Fig. 1 is a sectional view through a compressor and illustrating a preferred embodiment of the invention;

Fig. 2 is `a sectionalview taken along the line 2 2 of Fig. 1 and illustrating in elevation the operating parts of the compressor;

Fig. 3 is a sectional view'lalong the line 3-3 of y Figi, looking in the direction of the arrows;

50 Fig. 4 is a sectional v'iew'taken generally along the compressor discharge valve;

Fig. 5 is a fragmentary view of a detail taken in a plane along the lines-5. of Fig. 1, looking' in u the direction of the arrows;

improved form of compressor construction which is particularly adapted for vuse in a refrigerating the line 4-4 of Fig. 3 illustrating the'details of (Cl. 23o-145) Fig. 6 is a perspective view of the compressor blade; and Fig. '7 is a view similar to Fig. 2 of the operating parts of the compressor but with the parts of the compressor illustrated in a position 180 from 5 the position in which the parts are illustrated in Fig. 2. f

'I'he compressor mechanism, in general, may be said to comprise alcylinder, an eccentric oscillatable about the center of said cylinder, a rotor or sleeve'carried by the eccentric,and a blade reciprocable in a radial slot formed in the wall of the cylinder and biased into engagement with the outer surface of the rotor, all of which parts are submerged in a bath of oil for lubrication purposes when such compressor is employed for the purpose of compressing vaporous refrigerant. In the drawings such pumping mechanism is disclosed in connection with a compressor, the operating shaft of which extends through an opening in a wall thereof and which opening is provided with a seal to prevent the escape of lubricant and refrigerant from the compresson. the shaft externally of thel compressor `being adapted to be connected to a moving source of energy to be operated thereby.

A bearing block l0 provided with a base l2 is provided with a bearing I4 in which a shaft I6 is journalled, said shaft projecting at one end thereof from the bearing block i0, and having a seal, indicated generally at I8, operatively associated with such end of the shaft for preventingthe escape of regrigerant and lubricant from the compressor. A dome 20 is secured to the face oi? the bearing block l0 in such a manner as to pro-` vide a gas tight joint therewith, and is adapted to provide internally thereof a chamber forming a lubricant and refrigerant reservoir 22.

'I'he face 24 of the bearing block is provided with an annular flange 2 6, there being provided 40 in the face of the bearingblock within the area determined bythe flange 26, a recess 28 which is f partially closed by a plate 3i)- which lies fiat against the face Yof the bearing block and Within thevflange 26 which serves as a locating member 45 for the plate 30.

'A rigid cylinder block 32 has one face thereof disposed against lche plate 30 and has disposed against the other .face thereof, a somewhat similar plate 34 which is covered by an end cap 36, the 50. y

end cap 36, all of which parts are thereby rigidly secured to the bearing block I 0. The end plate 34 and the cap 36 provide therebetween a discharge valve chamber and are assembled and held together initially by a pair of bolts 39.

The side faces of the cylinder. block 32, which are in contact with the faces of the plates 38 and 34 as well as the faces of such plates, are smoothly `finished and are disposed parallel, and there is provided Within the space defined by the cylinder block 3 2 and the

end plates

36 and 34, a working chamber 44 through which the shaft I6 extends, the .shaft within such chamber being provided with an integral eccentric portion 46. VThe end cap 36 vis formed to provide a bearing 48 for the end of the shaft I6, and a washer is secured to the end of the shaft by a stud bolt 52 which washer bears against the end of the bearing 48 to provide a thrust bearing for the shaft I6.

The inner surface of the cylinder block 32 is arranged concentric with respect to the axis of the shaft I6 and is smooth and continuous except for an inlet opening 54 and a radial slot 56 extending transversely vof the cylinder block 32 and between the

end plates

30 and 34. The'end

plates

30 and 34 are provided with central openings therein through which the shaft I6 extends and through which openings lubricant may be supplied to the working parts of the compressing mechanism.

A rotor or sleeve 58 is freely disposed about the eccentric portion 46 of the shaft. lThe rotor or sleeve 58 is of slightly less length axially than the distance between the

end plates

30 and 34 and is adapted to form aworking seal therewith, lubricant under pressure being supplied to the inside ofthe rotor through the central openings in the end plates 38 and 34 whereby the abutting surfaces of the rotor and the end plates are lubricated. The rotor 58, when assembled on the eccentric 46- andupon rotation of the shaft I6, is adapted to oscillate or gyrate within the working y chamber 44,` the shortest radial distance between the most external portion of the eccentricl 46 and the inside wall of the cylinder block 32 being slightly greater (in the neighborhood of several ten thousandths'of an inch) than the radial thickness of the rotor 58, 'so that the rotordoes not contact the cylindrical wall of the cylinder block 32, a film of lubricant upon the cylindrical wall of the cylinder block 32 and the surface of the rotor 58 being relied upon to form a seal between the rotor and the cylinder wall.

A blade 62, shown in perspective in Fig. 6, is mounted for reclprocation within the radial slot 56 and is backed by a pair of springs 64 which bear against the shoulders 6'6 on the blade, and which springs are secured in position by a bracket 66' which is secured by means of a plurality of screws 10 to a portion of the cylinder block 32.. 'I'he blade 62, it will be observed, is provided on one end thereof with a flange 68. which forms a toe. The end of the blade and the flange 66 form a boot, the edge 69 thereof being designated as a heel. The underside of the toe or ange portion 66 of the boot is adapted to engage the outer surface of the sleeve l5I! for separating the space within the working chamber 44 on opposite sides of the blade 62. The radial slot 56 in. the cylinder block 32 is enlarged at the inner end thereof to provide a space 16 for accommodating the toe 66 ofthe blade during the portion of the stroke in which the rotor 66 travels from the podtion` in which it is illustrated in Pls. 2, to the position slot 12 extending transversely of the cylinder block is in communication with the space 10 and leads to a discharge opening 14 in the plate 3,4 which has associated therewith a discharge valve 16. A restricted communication between the discharge -slot 12 and the working chamber 44 is provided by means of an angularly disposed passageway 16 formed in the end plate 34. Just before the rotor 58 completes a stroke, the passageway 18 operates to place the discharge slot 12 in communication with the suction side of the rotor which tends to relieve the pressure in the discharge slot at such time.

In the normal operation of the pumping mechanism, a certain amount of lubricant passes through the pump and on account of the fact. that such lubricant is in liquid form and hence incompressible, some noise, which is made thereby or which may be due to the sudden drop in pressure in' the discharge slot 12, may be eliminated by use of the restricted passageway. l

. During the operation of the compressor, vaporous refrigerant is drawn in the cylinder chamber 44 through the inlet opening 54 and is compressed therein by the rotor 458 upon oscillation thereof andbetween the rotor 58 and the blade 62. The blade 62 follows the rotor and hence reciprocates within the slot 56. The gas aftercompression within the cylinder chamber 44 is discharged past the discharge valve 16 and through the conduit into the upper portion of the chamber 22. Refrigerant may escape from the upper end of the reservoir 22 through the tube 84 which leads to the exterior of the compressor and thence to an evaporator.

Within the recess 28 and secured to the shaft I6 a counterweight 66 is disposed which, in addition to balancing the shaft, operates as a lubricant pump for circulating lubricant through the passageway 88, the space around the seal I6, the passageway 96 and through a series of slots 92 in the bearing block affording `communication between the recess 26 and the reservoir 22. 'I'he cap 36 is provided with a plurality of openings 94 which communicate with the central opening inl the end plate 34 and afford -a passageway whereby the lubricant may communicatewith the the refrigerant-within the reservoir 22 is under.

the discharge pressure of the compressor since the compressor discharges into thereservoir 22.

'I'he portion of the blade 62 within the working chamber 44 is subject to the difference in,

pressure of the gas on the high and low pressure sides of the pump which, unless counteracted will tend to cause the blade 62 to bind in the slot 66. 'I'he tendency of the blade to bind in the slot under the pressure of the gas in the high pressure side of the compressor is substantially balanced by the head pressure acting on the rear face 1 98 of the blade, the springs 64 acting on therear face of the blade and the pressure on the high pressure side of the compressor to which that portion of the toe 66 of the blade is exposed between the fiat |66 on the high pressure side ofthe blade and the point of contact between the toe of the blade andthe rotor` I6. It will be observed from an inspecticnot Figs. 2 and '1,

l upon its rotor contacting or inner surface that it never contacts the rotor at va point more central than is indicated in Fig. 7.

In the position in which the parts are illustrated in Fig. 2, the point of contact between the toe of the blade and the rotor is near its extreme position where the effective area of the toe 68 exposed to the high pressure side of the compressor is the greatest, and in Fig. 7, the'point of contact between the toe 68 and the rotor 58 is at a position where the effective area of the toe 68 exposed to the high pressure side of the compressor is practically the smallest. It will thus be apparent -that the effective area of the toe 68 exposed to the high pressure side of the lcompressor varies With the position of rotor 58 and also varies with the pressure differential between the high and low pressure sides of the compressor. This design of a blade has the effectof balancing the various forces acting on the blade so as to eliminate any tendency thereof to bind whereby wear of the material of the cylinder blockf which defines the blade slot 56 is largely eliminated.

During the oif cycle of the condensing unit when the compressor is at rest, `the head pressure within the reservoir 422 causes seepage-of lubricant into the low and high pressure sides of the compressor so that upon starting the compressor after the same has been idle for a period of time, the lubricant which has seeped into the compressor is discharged therefrom during the iirst couple of revolutions thereof. As the discharge orifice from the compressor is designed primarily for the passage of a vaporous medium and not for a liquid medium, considerable restriction to the vescape of lubricant from the compressor is offered during its initial movement with the result that relatively high pressures are built up within the high pressure side of the compressor immediatelyafter starting. This high pressure is utilized for aiding in causing. the blade to follow the yrotor 58 as the toe portion 68' provides aneective area exposed to the high pressure side of the compressor which aids in holding the `blade 62 in contact with the rotor il. In this manner blade clicking is eliminated.

Blade clickingis caused by the binding of theblade due to the high pressure differential on opposite sides thereof and the ensuing separation and contact of the blade with'y the rotor'as the presure differential is built up and relieved. The under face |64 of the boot of the blade is on a line tangent to the radius at the point of contactI between the parts when they are in approximately the position illustrated in Fig. 7.

' The axis of the shaft I6 may be offset from the center about which the inner surface of the cylinder block 32 is formed up to one thousandth of an 'inch (.001") in the direction of the arrow to compensate for the eii'ect of the pressure differential between-the high and low pressure sides of the compressor, which pressure diiferenof the travel of the rotor 56 between the positionin which it is illustrated in Fig.v 7 and approxition.

axis of rotation of the shaft I6, and it is desirable to oset the shaft I6 so lasv to prevent the rotor from being forced into rubbing Acontact with the internal wall of the cylinder block 32.

While the invention has been described with some detail, it is to be understood that the description is for the purposes of illustration only and is not definitive of the limits of the inventive idea. 'I'he right is reserved to make such changes in the details of construction and arrangement of parts as will fall within the purview of the attached claims..

I claim:

1. A rotary compressor comprising a cylinder block providing a .cylindrical pumping chamber, a rotor oscillatable in said chamber, a blade reciprocably mounted in the wall of'said cylinder block and cooperable with said rotor for separat- I ing the high and low pressure sides of said comcillation thereof, the relationship, formation and' construction o f the blade and rotor being such that all contact between these two parts occurs upon that side of thecentral blade axis toward the high pressure side of the compressor.

2. A. rotary compressor comprisingv a cylinder, a rotor oscillatable in said cylinder, a blade reciprocably mounted in the wall of. said cylinder' and exposed to the discharge pressure of said compressor externally thereof, and spring means constraining said blade into engagement with said rotor for separatingl the high and low pressure sides of said compressor, said blade internally of said cylinder being provided with a laterally extending flange on the high pressure side thereof, the end of the flange extending farther toward the center of the cylinder than other portions thereof and which flange is engageable with said rotor upon oscillation thereof, thevpoint of engagement betweensaid rotor and said flange upon oscillation of said rotor being movable for varying the effective area of the flange exposed to the low pressure side of the compressor but always occurring at a point laterally oiset with respect to the central blade axis toward the blade flange. m

3. A compressor comprising a cylinder affording .a pumping chamber, a pressure chamber surrounding the cylinder adapted to receive the discharge from the pumping chamber, a rotor mounted for oscillation within said cylinder, said cylinder being provided` with a slot in a Wall thereof, a blade reciprocably mounted in said slot extending into said pumping chamber and exposed at the rear face thereof to said pressure chamber, said blade within said pumping chamber being provided with a laterally extending flange engaging said rotor for separating the high and low pressure sides of the compressor within the pumping chamber, and spring means constraining said blade for causing said flange to follow said rotor upon oscillation thereof, said flange being disposed only on the side of the blade exposed to the high pressure side of the compressor, the

engagement between the blade and the rotor occurring always between the ange and the rotor.

4. In' a compressor, a cylinder providing a pumping chamber internally thereof, a rotor oscillatable in said pumping chamber, said cylinder being provided with a slot in the wall thereof and in communication with said pumping chamber, a blade reciprocably mounted in said slot and provided with a laterally extending flange within the pumping' chamber, said flange being engageable with said rotor for separating the high and low pressure sides of the compressor, and spring means constraining said blade for holding Vsaid flange thereof in contact with said rotor upon osf' cillation thereof, said flange extending from the side of the blade exposed to the high pressure side of the compressor, the rotor contacting surface of the blade being so formed that the blade heel and rotor may never contact one another.

5. A rotary compressor comprising a cylinder, a rotor oscillatable in said cylinder, a blade reciprocably mounted in the wall of said cylinder and exposed to the discharge pressure of the cornpressor externally thereof, and spring means constraining said blade into engagement with said rotor for separating the high and low pressure sides of said compressor, said blade internally of said cylinder being provided with a laterally extending iiange only on the high pressure side thereof and which iiange is engageable with said rotor upon oscillation thereof, said flange providing an eifective area exposed to the high pressure side of the compressor which varies in accordance with .the pressure diierential between the high and low pressure sides of the compressor whereby said blade is constrained to follow said rotor, the parts being so proportioned and arranged with respect to one another that the variation in effective area at no time is so great as to expose a larger area of the rotor contacting surface of the flange to high pressure than is exposed upon the surface of the flange opposite Y the rotor contacting surface. 6. Arotar'y compressor having a cylinder and a rotor mounted for oscillation therein, a blade engaging the rotor for separating the `high an'd low sides of said compressor mounted to slide in a wall of said cylinder, Asaid blade having a flange at its rotor engaging end which extends only toward the high pressure side of the compressor, the rotor contacting surface of which forms Aan obtuse angle with the blade, said angularity being so related to the diameter and eccentricity of the rotor as to prevent contact, between the rotor and blade upon thatside of the central blade axis opposite to said flange.

'1. A rotary compressor having a cylinder and a rotor mounted for oscillation in said cylinder, said rotor comprising a sleeve mounted to rotate upon an eccentric and progressively to be associated with said cylinder, a blade mounted to slide in a slot in said cylinder and having a flanged portion laterally projecting beyond the body of the blade toward the discharge side 'of the compressor, said flange being spring urged in to contact with said sleeve and having its external portion exposed to high pressure said4 contact at all times being between said flange and said rotor. i

8. A rotary compressor comprising a cylinder. a rotor mounted eccentrically upon a shaft for oscillation inv said cylinder, and a blade mounted in a slot in said cylinder for separating the high and low sides of said compressor, the axis of said shaft and about which it rotates beingpermanently displaced from Athe center of said cylinder it rotates being permanently displaced from thecenter of said cylinder a distance sufficient to compensate for clearances in the general direction of the point of highest compression within the cylinder.

10. A rotary compressor comprising a cylinder, a rotor mounted eccentrically upon a shaft for oscillation in said cylinder, and a blade mounted in a slot in said cylinder for separating the high and low sides of said compressor, the axis of said shaft and about which it rotates being permanently displaced from the center of said cylinder a distance not greater than one thousandthof an inch in the general direction of thepoint of highest compression within the cylinder.

1l. A rotary compressor comprising a cylinder, ,l

oscillation in said cylinder, and a blade mounted in a slot in said cylinder for separatingthe high and low sides of said compressor, said shaft being mounted in said cylinder with its axis of rotation permanently displaced from the center of the cylinder toward the point of highest compression within the cylinder a distance suicient to compensate for bearing clearances.

12. A rotary compressor comprising a cylinder` block provided with a slot in the wall thereof, a rotor mounted for oscillation within said cylinder block, and a blade mounted for reciprocation within said slot, and provided with a laterally extending ange portion for engaging said rotor, and means constraining said blade for holding said flange portion thereof in engagement vwith said rotor upon oscillation thereof, said flange extending further toward the center of the cylinder than other portions of the blade, and the rotor, blade and flange being so positioned and dimensioned that the engagement between the blade and the rotor takes place at all times upon the flange portion of the blade.

13. A rotary compressor comprising a cylinder block affording a cylindrical pumping chamber, a rotor mounted for oscillation within said pumping chamber, said cylinder block being provided with a slot in the wall thereof, a blade slidably mounted within said block.and provided .with a ange -portion for contacting said rotor whereby to divide the high pressure side of the compressor from the low pressure `'side thereof. the rotorpresented surface of the flange forming an obtuse loscillation thereof, said blade and rotor contact lying constantly upon the rotor-presented vsurface of the blade-which lies between-the central axis of the blade and the tip of theange portion. Y

14. A rotary compressor comprising a cylinder block provided with acylindrical pumping chauxl 8,153,871 ber, a rotor oscillatable in said chamber, said cylinder block being provided with a slot in the wall thereof, a blade reciprocable in said slot 'and adapted to engage said rotor for dividing the high andlow pressure sides oi said compressor, an inlet to said pumping chamber on one side of said blade, a discharge from said pumping chamber upon the other side of said blade. said blade outside oi said pumping chamber being subject to the discharge pressure of said compressor, and spring means constrainingsaid blade into engagement with said rotor, -said blade internally of the pumping chamber beingprovided with a boot portion which is engageable withl said rotor,

15. Refrigerating apparatus comprising a compressor having a cylinder providing a pumping chamber, a rotor oscillatable in said cylinder, a blade slidably mounted in a slot in the wall oi' said cylinder and extending into the pumping chamber. 'said blade being provided with aV lateral flange upon one sid'e of the blade and exposed to the Lhigh pressure side ci' the compressor, said ilange being engageable with said rotor for separating the high and low pressure sides of the compressor, spring means constraining said blade to follow said rotor upon oscillation thereof, and means whereby the rear face of the blade externally of the cylinder is exposed to the discharge pressure ofthe compressor, the construction and arrangement of therotor, blade and ange being lsuch that the contactA between the flange and vrotor under the inuence ofsaid spring means and said external discharge. pressure produces a ,c moment in the direction of the center of thecylinder on the blade which `tends to rotate the same about its point of contact between the flange and the rotor. I v

EARL F. HUBAGKER.