US1696674A - Compressor - Google Patents

Description

Dec. 25, 1928.

W. FOURNESS CQMPRESSOR Filed March 8, 1927 2 Sheets-Sheet ATTOB NE V Dec. 25, 1928. 1,696,674

w. FOURNESS COMPRESS 0R Filed March 8, 1927 2 Sheets-6h?) 2 ME TOE/ IY/LFEED Foue/vssa ATTOENEK Patented Dec. 25, 1928.

UNITED STATES.

WILFRED FOURNESS, OF PASADENA, CALIFORNIA, ASSIGNOBQ BY MESNE ASSIGN- PATENT OFFICE.

MENTS, TO THE FOURNESS DEVELOPMENT CORPORATION, OF NEW YORK, N. Y,

A CORPORATION OF NEW YORK.

COMPRESSOR.

Application filed March 8, 1927. Serial No; 173,759.

pressors? I describe a compressor structure enclosed'in a housing, and having angularly displaced cylinders, and pistons operated by eccentrics to reciprocate therein. Valve pistons are also provided which control openings from the cylinders to the casing, and

similarly operated. In that form, the eccentrics serve to operate eccentric blocks, and upon these blocks are accommodated several slides, carrying the pistons operating in the stationary cylinders. It is obvious that such an arrangement involves somewhat complex mechanism. It is one of the objects of my invention to provide an eccentric operated compressor mechanism that is much simpler than the form just referred to, thereby making it possible to manufacture such compressors inexpensively.

It isanother object of my invention to improve in general reciprocating compressors of this type.

In such compressors, the valve pistons must of course be operated in synchronism with the main pistons, and this is accomplished as heretofore stated, by the aid of a valve eccentric. Usually the valve stroke lags behind that of the piston stroke, whereby the outlet valve is opened when the pistou nears the end of its stroke, and closes soon before the piston reverses. It is thus evident that the angular settings of the operating eccentrics must be such as to produce this effect. When operating the compressor shaft always in the same direction, it is a simple matter to fix the relative positions of the eccentrics once and for all to cause proper operation of the compressor.

However, it sometimes happens that the source of motion for the compressor shaft reverses in direction, as for example when that source is an electric motor. Under such circumstances, the relative angular positions of the valve eccentric and the piston eccentric must be changed. It is accordingly another object of my invention to make it possible to adjust these angular positions.

It is still another object to arrange matters in such a way that the change in angular position is produced automatically in response to the reversal of the direction of rotation.

My invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment of my invention. For this purpose I have shown a form in the drawings accompanying and forming part of the present specification. I shall now proceed to describe this form in detail, which illustratesthe general principles of my invention; but it is to be understood that this description is not to be taken in a limiting sense, since the scope of my invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a sectional perspective view, showing a compressor embodying my invention;

Fig. 2 is an elevation of an eccentric block that is used in connection with the compressor shown in Fig. 1;

Fig. 3 is a side view, partly in section,

of an eccentric assembly incorporating my invention; and n Fig. 4 is a sectional view, taken along plane 44 of Fig. 3.

In Fig. 1, there is shown a casing 11, with radiating fins 12, that can serve as an enclosure for the operating parts of the compressor. This casing is shown as a casting, with apertured standards 13 by the aid of which it may be appropriately supported on a base or the like. The casing 11 has a removable wall portion 14 to provide access to the interior, and also to support certain of the parts of the compressor, as hereinafter described. The removable wall 14 carries a pipe-like boss 15 in which is formed the inlet passageway 16, into which a pipe can be screwed at the threaded mouth 16. This inlet passageway serves to conduct the expanded refrigerant to the compressor, which refrigerant is thereby compressed, and escapes through the outlet openingl? on the top of the casing.

The wall 14 alsoprovides'in this instance for the insertion of a drive shaft 18, whereby motion is imparted to the compressor. For this purpose, the wall is provided with a comparatively long bearing boss 19. This boss has a bushing 20 serving as a bearing. In'order to provide a fluid tight packing and prevent substantial leakage of fluid from the interior of casing 11, I provide a plurality of conical packing rings 31 of resilient fibrous material, which surround shaft 18 and are urged in close contact with the bushing 20 by the aid of a compression spring 32. A plug 33 screwed into boss 19 serves to regulate the compression of this spring.

- In the present instance, a compressor body 34 is formed integrally with wall 14: Upon this body are supported cylinder blocks such as 37; two are shown in the drawings, arranged radially of shaft 18 and opposite each other. However, there are preferably four such blocks, angularly displaced from each other around the axis of shaft 18, the displacement being 90; Each cylinder block has a flange 35 which seats into a corresponding depression on the outer surface of body 34. A packing ring 36 is interposed between the flange and the body 37, and screws 38 serve to bolt the block securely in place.

The arrangement is such that the inlet passageway 16 communicates with the interior of the body 34 whence the gas to be compressed can enter the, cylinders. From the cylinders, the compressed gas is expelled into casing 11. Each block 37 therefore has a cylinder bore 39, radial with respect to shaft 18 in which piston 40 is reciproeated. Each cylinder block also has a slot 41 which is partly uncovered at the beginning "of the stroke, to permit gas to enter the bore 39 from body 34. Furthermore, a port 42 is provided adjacent the end of the bore for permitting the compressed gas to flow out of the cylinder. 7

This outlet port 42 is controlled in each instance by a reciprocating valve piston 43 operating in a valve bore 44 that parallels the cylinder bore. The-valve pistons 43 are arranged to operate in such manner that the port 42 is open during the latter part of the travel of main piston 40, but is closed soon before the piston 40 starts retracting. The manner in which the rotation of shaft 18 causes the pistons and valves to recipro cate can be most clearly understood from Figs. 2, 3 and 4. v

Locatedon shaft 18 are a pair of eccentries, 45 and 46. Each of these eccentrics operate in blocks, such as 47 and 48 each of which is provided with a bushing bearing 49 or 50. It is evident that if blocks 47 and 48 are restrained against rotation but not against radial motion, then rotation of cocentrics 45 and 46 will cause the center of the bore in the blocks to move in 'a circle around the axis of shaft 18, thereby causing the blocks to be moved closest successively to the angularly displaced cylinder blocks. Therefore, if these blocks be arranged to operate on pistons 40 and 43, a reciprocation could be effected; but provision of course must be made to permit the blocks to slide transversely of the piston axes. In my prior patent, this was accomplished by yokes, which however I obviate in a simple manner in my present invention.

-' For this purpose, I provide a sliding tongue and roove connection between the pistons and the blocks. This connection interlocks the pistons and the blocks, whereby the block movement serves to pull as well as push the pistons; and of course the pistons working in their bores effectively restrain the blocks from being carried around with the eccentrics. I As shown in Figs. 3 and 4, pistons 40 each have a flange 51 which may be round; and a tongue 52 is formed on the flange that coacts with groove 53 on block 47. The overhanging lip 54 on the block prevents movement of the pistons 40 radially of block 47 but the groove permits transverse movement of the block with respect to the piston. It is evident that this keyed construction needs no further lock, for the tongue 52 cannot be withdrawn from slot 53 when pistons 40 are in the cylinder bores.

The valve pistons 43 are of entirely similar construction, the tongues 55 thereof operating in grooves 56 on the block 48. Furthermore, it is found that for proper operation, thevalve pistons 43 must operate 120 behind the main pistons 40; and as shown in Fig. 4, this requirement necessitates having the eccentric 46 for the valves set at an angle of' 120 behind the main eccentric 45, the rotation of shaft 18 being counterclockwise as viewed in this figure. In case the shaft 18 should be reversed, it is evident,

that the valve eccentric would lag by 240 instead of 120 as it should.

In order to overcome this, I provide an angular adjustment for one of the eccentrics about shaft 18. Thus eccentric 46 can have a circular slot or depression 57 of about 240 extent, which is cut in its. face adjacent eccentric 45, and is freely movable on shaft 18. ,Its movement is however, limited by a key 58 carried by the shaft and working in the slot. This key can also serve to hold eccentric 45 in place on the shaft. \Vhcn the rotation of shaft 18 is counterclockwise, the key 58 is in the position indicated in Fig. 4, engaging one wall of slot 57 and driving the loose eccentric thereby. Now if the shaft 18 should be reversed, the eccentric 46 would momentarily remain stationary, until key 58 travels to the other wall of the slot. When that happens, and all lost motion is taken up, the main eccentric 45 is in the alternative position shown by the dotand-dash' lines. The valve eccentric then follows the main eccentric with a lag of 120, which is the desired relation.

not

It is thus seen that a lost motion connection is provided between the valve eccentric and the shaft 18, which is automatically taken up upon movement ofshaft 18 in either direction.

Referring now again to Fig. 1, the remaining mechanical features of the compressor can be outlined. The compressor body 34 has an end closure 59 in which there is a bearing 60 for shaft 18. A disc-like closure 61 covers this bearing. A connection 62 is provided in this closure for a safety valve 63, which permits escape of gas back to body 34, if it attains undesirably high pressure in the Casing 11. Furthermore, oil 64 is present in the bottom of casing 11, which serves as a reservoir for lubricant. Of course the vapor coming into the compressor at the inlet 16 may carry some lubricant, which finally settles and is commingled with oil 64.

For lubrication purposes, a pipe 65 connects the oil 64 with an aperture 66 in the bearing 60, the gas pressure in housing 11 serving to force oil upwardly into said pipe. The shaft 18 has an axial aperture 67 through which oil is forced, and the eccentrics 45 and 46 have passageways 68 and 69 communicating with this axial aperture and also with the bearings 49 and 50 of the blocks 47 and 48.

The mode of operation is apparent from the foregoing; As the eccentrics 45 and 46 are rotated, the pistons 40 and 43 move in and out of their bores, and the blocks 47 and 48 slide along the tongues 52 and 55 attached to these pistons. The valves operate to open the outlet ports 42 near the end of the stroke, to pass the compressed gas into casing 11.

' I claim:

1. In a compressor, a cylinder, an eccentric rotatable about an axis non-parallel with that of the cylinder, :1 block in which said eccentric rotates, and a piston operating in the cylinder, said piston being provided with an integral extension having a sliding connection with the block for causing the block to reciprocate the piston as the eccentric is rotated, and for permitting relative motion between the piston and the block transverse to the cylinder axis.

2. In a compressor, a cylinder, an eccen-' tric rotatable about an axis non-parallel with that of the cylinder, a block in which said eccentric rotates, and a piston operating in the cylinder, said piston having an integral extension, said block and extension having a tongue and groove connection permitting relative movement between the piston and the block in a direction transverse to the axis of the cylinder.

8. In a compressor, a cylinder, an eccentric, the axis of the cylinder being perpendicular to that of the eccentric, a piston opabout an axis, a plurality of cylinders angularly spaced aroundsaid axis and having axes radial to said axis, a block in which said eccentric rotates, a piston for eachof the cylinders, each of said pistons having an integral extension and a transverse sliding connection between each of the extensions and the block.

1 5. In a compressor, an eccentric rotatable about an axis, a pluralit of cylinders angularly spaced around said axis and having axes radialto said axis, a block in which said eccentric rotates, a piston for each of the cylinders, each of said pistons-having an integral extension, and a tongue and roove sliding connection between each of t e extensions and the block, said connection being transverse and of such form as to prevent separation between the pistons and the block while permitting relative sliding.

6. In combination, a piston, a cylinder, rotatablemeans for causing relative motion between the piston and the cylinder, valve mechanism for the cylinder operated b said means, and means whereby the operation of the valve mechanism stays properly timed for either direction of rotation of the means that causes relative motion between the piston and cylinder, comprising a lost motion connection between said latter means and one of the mechanisms operated thereby.

7. In combination, a piston, a cylinder in which said piston operates, a rotatable shaft,

mechanism whereby the shaft operates the piston, a valve mechanism for the cylinder also operated by the shaft, and a lost motion connection between one of said mechanisms and the shaft, whereby the valve mechanism remains properly timed for either direction of rotation of the shaft.

8. In combination, a shaft, a pair of coeentrics driven by the shaft, one of said eeccntries having a lost motion connection with the shaft, of such angular extent that for either direction of rotation of the shaft, one of said eccentrics leads the other by the same angle, a piston and a cylinder operated for relative motion by one of said eccentrics, and a valve mechanism therefor operated by the other eccentric.

' 9. In combination, a shaft, a pair of cocentrics, one of said eccentrics being rigidly fastened to the shaft, the other eccentric having a groove adjacent the shaft of circular form but of less angular extent than a complete circle, a key carried by the shaft and operating in the groove in such manner that the eccentric is driven thereby as soon as the key moves to the end of the groove, a piston and cylinder operated by one of said eccentrics, and a valve mechanism for 5 the cylinder operated by the other eccentric, the angular extent of the groove in one of the eccentrics being such that the angular lag between the two eccentrics remains the same for either direction of rotation of the shaft. It)

In testimony whereof I have hereunto set my hand.

WILFRED FOURNESS.

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