US2100014A - Compressor - Google Patents

Description

Nov. 23, 1-937. F. M. MO'CRACKEN COMPRES SOB 3 Sheets-Sheet l INVENTOR. FRED M. MCCRACKEN. W 7

ATTORNEY.

Filed May 29, 1933 l a 4A A6 fi ll Z5 Nov. 23, 1937.

4, 11 1 2 N E w R w R CE m m .C M F Filed May 29, 1955 5 Sheets-Sheet 2 INVENTOR.

Fazo M. McCRAcKEN,

' Nov. 23, 1937.

F. M. MCCRACKEN COMPRESSOR Filed May 29, 1955 3 Sheets-Sheet 3 INVENTOR.

FRED M. McCRAcKaNs Patented Nov. 23, 1937 PATENT OFFICE 1 2,100,014 COMPRESSOR Fred M. McCracken, Norwood, Ohio Application May 29, 1933, Serial No. 673,393

10 Claims.

This invention relates to compressors in general. but more'particularly to a compressor suitable for compressing a chemical gas such as used in domestic and other. refrigerating devices but it will beunderstood that it may be used for other compression purposes as well.

Heretofore, two different'principles of com-- pressors have generally been used for this pura ing the's'eal confining the gas.

' pose-the reciprocating piston type and the rotary type. The piston type of compressor has usually been driven by a belt from a power device, such as an electric motor, and this arrangement enabled the use of a fan on the motor shaft to provide a, forced draft for cooling the condenser of the refrigeration device but it made necessary the use of a shaft seal around the shaft of the compressor to prevent escape of the gas from within. Such seals have invariably given considerable trouble and proven very unreliable. Other piston types 'of compressors have been directly connected to the motor and both motor and compressor hermetically sealed in a container .withthe gas thus obviating the requirement fora shaft seal but this arrangem'ent did not; permit of the use'of a fan draft I for cooling thecondenser, and it had the added disadvantagejthat themotor could not be serviced w'ithout-"unsealing the container and thereby liberating the 'gas. The rotary type of compressor, being usually directly connected to the motor, was not favorable'to the use of a shaft seal because of the high speed of the shaft and therefore this type of compressor, together'with the motor could not be serviced without destroy- Another disadvantage of both the piston type and the rotary type of compressor is that an enormous amount of power is wasted in overcoming the friction of the moving parts even with the best of workmanship and good lubrication and in the piston type of compressor there is an additional Waste of powerdue to starting and stopping the recipro'cating parts at each end of their stroke which occurs many hundreds of times per minute. Furthermore, friction inevitably results in wear onthe parts and consequent loss'of efficiency in' compression thus making service and replacement of parts frequently necessary in order to maintain satisfactory performance, and the expense incident thereto greatly increases the cost of electric refrigeration to the user or places a serious burden on the manufacturer or dealer. ."On'e object of this invention therefore is to provide a compressor that is devoid of any reciproc'ating parts, such as pistons or cylinders.

or of any revolving parts, such as the eccentrics, rollers or blades common to rotary types of compressors thereby eliminating the friction and resultant wear incident thereto, conserving pow-1 er and effecting real economy in operating and maintenance expense.

Another object is to provide a compressor which can be hermetically sealed independent of the power device thus having the shaft of the power device available for the application of a fan to provide a forced draft for cooling a condenser and also thus avoiding the use of a shaft seal so that the power device may be readily replaced or serviced without liberating any of the refrigerating gas.

Another object is to provide a compressor that can be directly connected to the actuating member of a power device (such as the shaft of an electric motor) without the use of a clutch, coupling or any tied-up connection.

Another object is to provide a compressor having only one major power-actuated element directly adapted to effect compression of the gas,

thus, making for simplicity and low cost of mancompact form yet easily assembled and the parts thereof readily accessible for examination or replacement.

Another object is to obtain a higher degree of volumetric efiiciency than that which is possible with other types of compressors. I These and other objects will be apparent from the following description and the accompanying drawings which illustrate a preferred form of the invention. 0 My invention will be further readily understood from the following description and claims and from the drawings, in which latter:

Fig. l is an externalside elevation of the compressor unit and the attached power device.

Fig. 2 is an end elevation of the same as viewed from the compressor end.

Fig. 3 is a sectional elevation through the compressor unit taken substantially-on a line 3-3 of Fig.2. 0

Fig. 4 is a sectional of Fig. 3. Fig. 5 is a sectional view taken on a line 5-5 of F g, 3.

Fig. 6 is a sectional view taken on the line 6-6 of Fig. 3.

Fig. '7 is a sectional view taken on a line 1-1 of Fig. 3.

Figs. 8, 9 and 10 are comparative views to Fig. 4 and show the relative positions of the compression elements at different stages of the cycle of movement.

Fig. 11 is a profile view of the discharge valve disc.

Fig. 12 is a perspective view of the blade or division bar.

Fig. 13 is a longitudinal section of a modified form of compressor unit.

Fig. 14 is 'a sectional view'taken on a line |4|4 of Fig. 13.

Figs. 15, 16 and 1'7 are sectional views taken on the line ||5 of Fig. 13, and, in connection with Fig. 14, show the relative positions of the compression elements at different stages of the cycle of movement.

In the drawings, 20 represents'a compressor housing having a portion 2| arranged for attachment to any suitable structure by means of bolts or otherwise.

The body portion of the'housing 20 is preferably of cylindric form and rigidly attached to one end thereof is a cap'or head plate 22 which is secured by means of screws 23. The cap plate 22 not only serves as a closure for that end of the housing but also as one of the side plates for the compression chamber 24 and as a mounting plate for the cylinder 25 and the other side plate 26 which are secured to the plate 22 by means of the screws 27. This assembly consisting of the cylinder 25 and the plates 22 and 26 may be termed the cylinder unit and in order that the annular location thereof relative to the housing 20 may beestablishedwith precision, the said housing is bored out to an accurate diameter and the cylinder 25 is accurately positioned therein concentric to the outside diameter so that .the axis thereof coincides with the axis of the bore in the housing.

Positioned within the cylinder 25 and laterally confined between the plates 22 and 26 is a movable member 28 of cylindric form which. in the absence of a more appropriate term, may be called the eccentric merely because it is normally positioned and held eccentrically within the cylinder, that is, the axis of the eccentric is spaced from the axis of the cylinder 25 a distance equal to exactly one half the difference between the diameter of the cylinder bore and the-diameter of the eccentric so that the peripheral surface of the eccentric isthus in contact with the wall of the cylinder.

The eccentric 28 is provided with a hub-like portion 29 concentric thereto which extends laterally through an opening concentrically located in the plate 26 and comprises a flange 3| and a threaded tenon 32. The eccentric 28 is further provided with a detachable cup-like extension 33 which is concentrically mounted on the tenon 32 and held securely against the face of the flange 3| by a jam nut 34. The extension 33 has a flange 35 to which is rigidly secured one endof a cylindric metal bellows or -sylphon 36 which has its other end similarly .attached to the plate 26. Thus'there is provided a gas-tight connection of conduit form, axially flexible but torsionally rigid, between the cylinder 25 which is stationary and the eccentric 28 which is movable.

Attached to the housing 20 at the end thereof opposite the cylinder unit, is a power device 3?.

here shown as an electric motor having a rotary shaft 38 and bearing caps 38 and 40 which support said shaft.

In order that the annular location and alignment of the shaft 38 relative to the cylinder 25 may be established with precision, the housing 20, at the motor end, is bored out to an accurate diameter and exactly concentric with the bore at the other end which positions thecylinder and the cap 40 is provided with a flange 4| which is accurately machined for a snug fit in the housing and exactly concentric to the bore of the bearing member 42 secured in the cap 46 for supporting the shaft 38. Thus the axis of the said shaft is established exactly concentric and in alignment with the axis of the cylinder 25. The motor 31 is secured to the housing 20 by the screws 43 which extend through ears 4% on the housing and are threaded into the cap 49.

The shaft 38 is so arranged that the rotation thereof will cause movement of the eccentric" 28-not rotary movement because the said eccentric is restrained from any rotary movement by its connection to the plate 26 through the bellows 36 but the movement is'a gyratory movement of the eccentrics" axis around the axis of ference between the diameter of the bore in the cylinder and the diameter of the eccentric 28 so as to hold the eccentric 28 eccentrically within the said bore to such an extent that the peripheral surface of the eccentric 28' is in contact with the wall of the cylinder, as previously referred to. Thus, as the shaft 38 rotates, the eccentric 28 is caused to walk-around within the bore of the cylinder 25, always in peripheral contact with the wall of the cylinder and held in constant peripheral relation thereto by the torsionally rigid sylphon 36.

In order to utilize this movement for compressing a vapor or gas, there is provided a blade or division .bar 46 which is preferably confined in a radial slot 41 in the eccentric 28 and yieldingly held into contact with the wall of the cylinder 25 by compression springs 48, the said blade being angularly located intermediate an intake port 49 in the eccentric 28 and a discharge valve 56 in the cylinder 25 thus serving as a wall to separate the intake from the discharge port. By this arrangement, gas enters the chamber 24 on one side of the blade 46 through the port 49 and is discharged therefrom on the other side of the blade through the valve 58 which comprises a 'port-hole 5| normally closed by a disc 52 under the influence of a compression spring 53 which is located in a chamber'54 and confined between the said disc and a retaining screw 55 mounted in the cylinder 25. The force of the compressed it in correct position.

blade 46, that is, when substantially half a charge of gas has been taken into the chamber on one side of the blade and compression on the other side has been half accomplished. When the eccentric is in this position, the point of contact between the said eccentric and the wall of the cylinder is opposite the blade H6 on a. direct line through the center of the blade and the axis of the said eccentric and the axis of the cylinder 25 is also on said line intermediate the blade and the eccentrics axis.

Figs. 8, 9 and 10 show the position of the eccentric 28 at different stages in its cycle of movement. For example: When the shaft has rotated clockwise substantially 90 degrees from the position shownein Fig. 5, the axis of the said eccentric has thus been moved .90 degrees clockwise around the axis of the cylinder 25 to the position shown in Fig. 8 resulting in nearly full accomplishment of compression and discharge on that side of the blade and almost a full charge of gas in the chamber on the intake side of the blade.

A further 90 degree movement of the shaft 3% brings the eccentric into the position shown in Fig. 9 wherein compression has been fully accomplished and the chamber 2% supplied with a full charge of gas compression of which is about to begin on the discharge side and a new charge about to be taken in on the intake side.

-A-still further 90 degree rotation of the shaft 38 will result in positioning the eccentric as shown in Fig. 10 wherein partial compression has taken place on the discharge side and a partial charge of gas taken in on the intake side.

The complete cycle of movement of the eccentric 28 will have been accomplished with a further 90 degrees of rotation of the shaft 38 resulting in the said eccentric again occupying the position shown in Fig.5. Each rotation of the shaft 33 will thus effect one complete cycle of movement of the eccentric 28, that is, one full planetary circuit of the said eccentrics axis around the axis of the cylinder 25, resulting in one full charge of gas being compressed and discharged and another full charge being taken in.

In order that gas may be conducted from the cooling element of a refrigerator (when the device, is thus applied), or from any other source, to the intake port 49 of the compressor, the plate 22 may be provided with a suitable fitting such as 51 which is arranged for connection with said cooling element by tubing or otherwise. Openings 5B, 59 and 60 arranged respectively in plate 22, cylinder 25 and plate 26 provide a passagewayfor the gas from the fitting 51 into the chamber within the bellows 36 from whence it may pass to the intake port d9 through an opening 6I which extends longitudinally through the eccentric'28 from the flange 3i to the face adjacent the'plate 22. The intake port M is shown as comprising a channel recess in the side face of the eccentric 28 and may, if desired, be arranged in duplicate, one port on each side of the eccentric as shown.

Transit of the compressed gas from the discharge valve 50 may be provided for by a passageway comprising openings 62 and 63 arrangedrespectively in cylinder 25 and plate 22, the opening 62 communicating with the valve chamber 54 and opening 63 with a suitable fitting such as 6A which is arranged for connection, by tubing or other wise with the condenser of a refrigerator or other device.

In order to provide ample lubrication for the bearing of the eccentric 28 on the shaft extension 45 and also for the bearing c2 of the shaft 38,

the chamber within the housing 20 may contain oil in sufficient quantity to immerse both bearings, in which case the cap M is provided with a suitable oil retainer or seal 65 to prevent escape of oil around the shaft into the motor.

Inasmuch as an induced draft of circulating air is advantageous for radiating generated heat from the motor and compressor and as a forced draft is practically necessary for efficient cooling of the condenser coil, the free end of the motor shaft 38 is provided with a fan 66 to serve this purpose.

The modified form of the compressor unit shown in Figs. 13 to 1'7 inclusive embodies the same basic idea hereinbefore described and performs the function of compression in a manner which accomplishes similar results. The practical difference herein resides principally in the reversal of the primary elements-the cylinder being movable and the eccentric being stationary.

In this instance, lil represents the compressor housing having a portion ii for mounting purposes. Rigidly attached to one end of the housing is a supporting cap i2 which is snugly fitted into a bore in the housing and secured by means of screws 73. The cap 12 is provided with an extension M to support the eccentric i5 which is of cyiindric form and comprises a portion it having an extension Ti by which the said eccentrio is supported and securely held in the bore 78 in the cap extension M thus positioning the said eccentric exactly concentric to the bore in the housing '70. e

The cylinder unit, comprises the cylinder Iii and side plates 80 and ti which enclose the compression chamber 82 and which are secured together by screws 83. Rigidly secured to plate fl is one end of a cylindric metal bellows M which has its other end similarly attached to the cap 52. Thus there is provided a gas-tight connection of conduit form, axially flexible but torsionaliy rigid between the eccentric it which is stationary and the cylinder it which is movable.

The motor cap 85 is mounted on the end of the housing Iii and carries abearing 86 which supports the motor shaft t'l.

In order that the annular location and alignment of the shaft tl relative to the eccentric l5 may be established with precision, the housing in at the motor end is bored out to an accurate diameter and exactly concentric with the bore at the other endwhich positions the eccentric and the cap 85 is provided with a flange 88 which is accurately machined for a snug fit in the housing and exactly concentric to the bore of the bearing member 86. Thus the axis of the shaft 81 is established exactly concentric and in alignment with the axis of the eccentric F5. The motor can 85 is secured to the housing iii by the screws 89 which extend through ears W on the housing and are threaded into the cap.

' extension 9! of the shaft Bl said extension being eccentric to the axis of the'said shaft in amount sufficient to hold the cylinder 79 eccentric to the eccentric 15 to such an extent that the peripheral surface of the said eccentric is in contact with the wall of the said cylinder. Thus, as the shaft 81 rotates, the cylinder unit" is caused to walkaround the eccentric 15 always maintaining peripheral contact between the said eccentric and the wall of the cylinder and held in constant peripheral relation thereto by the torsionally rigid sylphon 84.

In this instancefthe blade or division bar 92 is shown as being confined in a radial slot 93 in the cylinder 19 and yieldingly held into contact with the eccentric by compression springs 94, the point of contact being substantially midway between the intake port 95 and discharge valve 96 both of which are positioned in the eccentric 15. By this arrangement, the gas enters the chamber 82 on one side of the blade 92 through the port 95 and is discharged therefrom on the other side of the blade through the valve 96 which comprises a port-hole 91 normally closed by a disc 98 under the influence of a compression spring 99 which is located in a chamber I and confined between the said disc and the bottom wall of the said chamber. The port-hole 91 is embodied in a disc IM which is securely held in a recess in the eccentric 15. The force of the compression acting upon that portion of the surface of the disc 98 which is exposed thereto through the port-hole 91 causes the said disc to move against the action of the spring 99 and thus permit the compressed gas to pass through the said port-hole into the chamber l00. So that the movement of the disc 98 may be limited to a desirable extent, the chamber I00 is formed I with a central stem I82 of proper length and this a'.;o serves as a pilot for the spring 99 to define its position.

In order that gas may be conducted from an external source to the intake port 95, the cap 12 -may be provided with a suitable fitting E03 for tube connection and an opening 194 in the said cap may provide a passageway for the gas from the said fitting into the chamber within the bellows 84 from whence it may pass to the of the eccentric.

Transit of the compressed gas from the valve 96 may be provided for by a passageway E06 extending radially through the eccentric 15 and' communicating at its outer end with the chamber 590 through an opening 901 in the wall of the stem Hi2 and at its inner end with a passageway 9% extending longitudinally through the eccentric 15 to the bore 18 and thence through an opening its to a suitable fitting i 10 mounted in the cap 12 and arranged for tubing connection with the device to be served.

Figs. 14, l5, l6 and 17 show the position of the cylinder is at different stages in its cycle of movement. Fig. 14 shows the position when half a chargeoi gas has been taken into the chamber on one side of the blade and compression on the other side has been half accomplished. Fig. 15 shows the position when the shaft 81 has rotated clockwise 90 degrees from the position shown in Fig. 14 thus moving the axis of the cylinder iii an equivalent amount around the axis of-the eccentric15. Fig. 16 shows the position after an additional 90 degrees of movement and Fig. 17 shows a still further movement of 90 degrees. It will thus be seen that a complete rotation of the shaft 81 will effect a complete cycle of movement of the cylinder 19, that is, one full planetary circuit of the cylinders axis around the axis of the eccentric 15, resulting in one full charge of gas being compressed and another full charge being taken in.

Ample lubrication for the bearing of the plate 88 on theshaft extension 9| and also for the shaft bearing 86 may be provided for by charging the housing 10 with, suflicient quantity of lubricating oil to immerse both bearings. To prevent escape of any of such oil around the shaft into the motor, the cap 85 may be provided with a suitable oil seal Ill.

From the foregoing, it will be apparent that I have provided a compressor which accomplishes, in a novel and practical manner, all of the objectives stated herein.

It is to be understood that the disclosure made. herein is a preferred form and that the various elements of the device may be modified to suit particular requirements without departing from the spirit and scope of the invention as set forth in the following claims.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent, is:

LA compression device comprising a member having a cylindric chamber, a cylindric member enclosed within said chamber and disposed ec-,

centric thereto, an intake port in one of said members, a discharge port in one of said members, ablade movably mounted in one of said members, yieldingly held into peripheral contact with the other of said members and positioned radially intermediate said ports, said members thus functioning as a pump when one member is held stationary and the other member is given a gyratory motion relative thereto, sealed connecting means between said members comprising a vapor-tight flexible tube arranged so that the chamber therewithin receives leakage of vapor from the compression chamber of said pump thus preventing escape thereof to the atmosphere, and a device to actuate said other member in a gyratory manner.

2. A compression device comprising a stationary'cylindric member, a movable cylindric memher, one of said members encompassing the other and arranged with its axis parallel to the axis of said other member but displaced relative thereto, an intake port in one of said members, a discharge port in one of said members, a blade movably mounted in one of said members, yieldingly held into peripheral contact with the other of said members and positioned radially intermediate said ports, said members thus functioning as a pump when said movable member is given a gyratory movement, a vapor-tight flexible tubu .lar structure attachedat one end to said stationtion to said chamber, one of said walls having an aperture located axially therein and said cylindric member having an axially disposed extension projecting through said aperture and terminating in a portion remotely spaced from said apertured' wall, one of said members being stationary and the other being arranged for gyratory movement relative thereto whereby vapor may be compressed within said chamber, a vapor-tight flexible tubular structure encompassing said extension and having one end hermetically connected to said remote portion thereof and having manner.

4. In a gyratory compressor, the combination with a cylinder member and an eccentric member, one of which is stationary and the other movable in a gyratory manner, of a vapor-tight flexible tubular structure having one end hermetically connected to said stationary member and the other end hermetically connected to said movable member, said structure acting to prevent rotation of said movable member about its axis without restricting its freedom to gyrate and being arranged in relation to said members so as to receive within said tubular structure leakage of vapor from the compression chamber of said compressor and thus serve as a seal to prevent escape. of said vapor to the atmosphere.

5. The combination with a gyratory compressor mechanism comprising a cylinder member provided with end walls and an eccentric member confined therebetween, of hermetically attached connecting means joining said cylinder member to said eccentric member, said means comprising a vapor-tight flexible tubular structure arranged in relation to said. members so that compressed vapor escaping between said eccentric member and the surface of the end wall adjacent to said structure will be confined by and within said structure which thus serves as a seal to prevent escape of said vapor to the atmosphere.

6. Means for sealing a gyratory compression mechanism comprising a cylinder element and an eccentric element confined therewithin, which consists in the provision of a vapor-tight tubular structure, axially flexible but torsionally non-flexible, said structure being hermetically connected at one end to said cylinder element and hermetically connected at its other end to said eccentric element, and being arranged in relation to said elements so that the chamber within said struc ture will receive leakage of vapor from the compression chamber of said compression mechanism and thus said vapor will be confined by and within said structure so that it may be available for redelivery to the said compression chamber.

7. In a gyratory compressor mechanism wherein vapor is compressed within a cylinder element by an eccentric element as a result of gyratory motion of one of said elements, thecombination of an intake passageway map be conducted to the compression chamber within said cylinder element, and hermetically sealed connecting means joining said cylinder element to said eccentric element, said means comprising a flexible tubular structure arranged in relation to said elements so that leakage of vapor from said compression chamber will be received by and within said tubular structure, said tubular structure having communication with said passageway whereby said leakage may be returned to said compression chamber.

8. In a gyratory compressor mechanism wherein vapor is compressed within a cylinder element by an eccentric element as a result of gyratory motion of one of said elements, an intake passageway through which vapor may be conducted to the compression chamber within said cylinder element, said passageway comprising a flexible tubular structure having one end hermetically connected to said cylinder element and the other end hermetically connected to said eccentric element, said tubular structure being arranged in relation to said elements so that leakage of vapor from said compression chamber will be received within said passageway so that said leakage may be returned to said compression chamber.

9, Means for sealing a gyratory compression mechanism comprising a cylinder element having a compressor chamber and an eccentric element confined therewithin, which consists in the pro vision of connecting means between said elements comprising a vapor-tight axially flexible but torsionally rigid tubular structure and a fully rigid cylindric structure, one of said structures freely encompassing the other, said cylindric structure being hermetically connected at one end to one of said elements and similarly connected at its other end to one end of said tubular structure, the other end of said tubular structure being hermetically connected to the other of said elements, said structures being arranged in relation to said elements so that the free space between said structures will receive leakage of vapor from the compression chamber of said compression mechanism and thus said vapor will be confined by and within said connecting means so that it may be available for redelivery to the said compression chamber.

10. The combination with a gyratory compressor mechanism comprising a cylinder member provided with end walls and an eccentric member confined therebetween, of hermetically attached cylindric connecting means joining said cylinder member to said eccentric member, said means comprising a vapor-tight flexible tubular structure and being arranged in relation to said members so that compressed vapor escaping between said eccentric member and the surface of the end wall adjacent to said connecting means will be confined by and within said means which thus serves as a seal to prevent escape of said vapor to the; atmosphere.

through which vapor

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