US2643817A - Compressor - Google Patents

Description

-3Q 1953 v. s. MAKAROFF EI'AL 2,643,817

June 1953 v. s. MAKAROFF ETAL 2954398317 COMPRESSOR Filed Nov. 22, 1952 2 Sheets-Sheet 2 Fig? INVENTOR ww/m S.MHKHROFF Patented June 30, 1953 Vadim s. Makaroff, New York, N. Y., and Alexis I E. Jackson, Norwalk,-Conn.

Application November 22,1952, Serial No. 321,965

Claims. (01. 230-147). v

The invention relates to rotary compressors of the type shown in U. S. Patent No. 1,664,733 to Braun and is a continuation-in-part of our U. S. application, Serial No. 304,512, filed August 15, 1952.

The prior patent relates to a compressor having a cylindrical chamber in which an eccentrically mounted cylindrical piston gyrates. The

, piston is provided with a tail blade which reciprocates within an oscillatory valve block to control the discharge of the compressed gas.

, The prior patent discloses a structure which is mechanically simplebut is not thermo-dynamically efficient. Among the reasons for such inefficiency are the opening and closing of the port in'the valve block at the wrong times and the failure to recognize the fact that different generated pressures require different relationships between the tail blade on the one hand, and the center of the piston or of the'valve block v on the other hand.

Among the objects of the present invention are to overcome the aforesaid disadvantages.

In the drawings:

Fig. 1 is a diagram of a compressor, illustrating the position'of the piston at the opening point of the discharge valve port, of an embodiment .of the invention in which the tail blade is mounted on a radius of the the slot for the tail valve center;

piston, and in which blade passes through the Fig. 2 is a diagram of the same compressor as Fig. 1, illustrating the position of the piston at the closing point of the discharge valve port;

Fig. 3 is a diagram of another embodiment of a compressor, illustrating the position of the piston at the opening point of the discharge valve port, with the tail blade in non-radial position with respect to a piston radius; 7, I v

Fig. 4 is a diagram of the same compressor as Fig. 3, illustrating the position of the piston at the closing point of the discharge valve port;

Fig. 5 is a diagram of another form of compressor, illustrating the position of the piston at 'the opening point of the discharge valve port, in

which the tail blade is mounted'on a radius of the piston, and in which the slot for the tail. v blade is offset from the center of the valve member;

Fig. 6 is a transverse vertical section through a compressor, according to the invention, taken on the line 6-6 of Fig. 7 and illustrating the I compressor structure; and

Fig. '7 is a transverse vertical section of a compressor, according to the invention, taken on the valve-port partly open. In this figure the offset of the tail blade is the same as in Figs. 3 and 4. Fig."8 is a diagram of still another'form of fcompressor, illustrating the position of the piston at the'opening point of thedischarge valve port, in which the tail blade is in non-radial position with respect to a piston'radius, and in which the slot for the tail blade is offset from the center of the valve membe In the following description in the claims,

various details will beidentified by specific names for-convenience, but'theyare intended to be as generic in their application as the art will permit.

v the several figures of the drawings.

Like reference characters denote like parts in In the drawings accompanying and forming part of this specification, certain specific disclosure of the invention is made for purposes of explanation, but-it willbe understood that the details may be modified in'various respects: withu out departure from the broad aspectof the in- :ventioni- Referring to the drawings; and more particularly to Figs; 6 and 7, 'the compressor structure will first'be described. The compressor comprises a casing I 0 having amain cylindrical chamber or cylin'der I I; acylindrical valve housing I2 parallel-'thereto,'=the housing and chamber intersect- I ing to: form an arcuate'space through which the 1 block l5 has-a: slot in which the tail blade 13 j The casing] 01 tailbladelil of the piston passes. An eccentrically gyrated cylindrical piston I4 is mounted in the main chamber and an oscillatory valve block' or member I 5 is mounted in the valve housing I2. The piston I4 has the'ofi'set, integral tail [blade I3 whose center line is non-radial with respect to the center of the piston I4. The valve reciprocates. V 1 has a lowpressure inlet duct I B and a high pressure outlet duct II. The valve block I5 has adischar'ge port I8 adapted to connect the high pressurefduct 'll 'and'the main f chamber II at times, and to disconnect the high pressure duct and the maincha'mber at other times. The casing has-recess 2| to provide clearance for tail blade l3. It will be noted that the intersectionof the valve housing -I2-and*main cylindrical chamber forms a 1ip2 2 adjacent-the port I 8. It will be seen from discussion below of closing of the valve port I8.

that'this lip 22 is'a critical point for completion The"casinglll'coinprises end plates I9 with a body member '20- clamped in between bya line I--I of Fig. 6, and showing the discharge halves of the valve member. -I5- together.

series of bolts. "'--Th'e end-plates I9 have recesses 24 for ring-like hubs 23 which connect thetwo The ;pipes leading to a common piped-1 valve member bears on, and, is journaled in, the housing or socket ii. The sides of the tail blade [3 slidably engage with the end plates IS.

The end plates l9 have bearings 25 journaling a main shaft 26 which has crank arms 21 between which extends a crank pin 28. Around the crank pin 28 is a split bearing 29 having longitudinal holes 30 therein. The split bearing 29 is shorter than the length of the piston [4, thus providing spaces 32 communicating with the holes for the circulation of oil. The

, piston l4 slidably engages the end plates 19.

The end plates have clearance spaces 3! to permit rotation of the crank arms '21.

An oil circulating system is provided for lubricating and sealing the parts. Thedischarge duct (1 connects with a storage tank (not shown) for the compressed gas as indicated in the prior application. The bottom of the storage tank constitutes an oil reservoir. The main oil feed pipe 33 feeds oil from the bottom of the oil reservoir to the space 32. inside of the piston 14-. The main bearings .-2;5 have annular oil recesses to which pipes 36 are connected, these which leads to. the supply pipe 38 which connects with the intake duct. Y

It will be understood that the crankshaft 26 r en y any suitab e means through a suitab e c up n 39: This causes-th p st n 14 to gyrateeccentrically around the main cylinder H clockwise as indicated'by the arrows. Gas is drawn inthrough the intake duct 16 and dis har d throu h; the outletdu t The lubrication system works as follows. Oil

un er p e su r m the r erv ir is forc d through pipe 33, in the direction of the arrow, in orth pac 3.2, hence int the ma n cylind r ljl into the crank; bearing and piston bearin thence out. through the two main bearings 25, thence into the bearing drain pipes 35 and through common pipe .31 into. the inlet pipe 38. The tail blade l3 is-provided with oil channels 39 which conduct oilto the valve block l5, which oil drains back into the main cylinder.

Itwill be noted that the tailblade' l3 .in-Figs. 6 and HS offset with respect to thepiston center, that is, it is noneradial; and that the center line of the tail blade passes through the center of rotation of the valve block l5. This particular relationship of piston, tail blade and valve is but one example of a variety of relationships.

W have und tha or est efficiency at any ,given speed of rotation, this relationship depends upon the value oi the-pressure to which it is desired to compress the gas.

Examples of other relationships. for other press r s a e hew in Figs 1 to. 5. and}. In 1 and 2, the center line of the tail coincides with the piston radius and passes through the center of the valve. member. In Figs. 3 and 4, the relationship is substantially the same as illustrated in Figs. 6,:and 7. In Fig; 5, the center line. of the tail blade is coincident with a piston radius and passes through the-valve member at a pointyofi'set from the center of rotation, It will be understood that, the tail-blade may have other angles with respect: to the piston, and the slot for the tail blade may be offset other distances from the valve axis. Also. as illustrated in Fig. 8, arrangements of both offset: tail blade and offset slot in the same compressor may be provided according to our invention.

I It willbeunderstood thatthe: bearing between the gyrating piston I14 .andthe crank Din-on times referred to as the contact point or sealing point; this is the point (42 for example in Fig. 1) through which the line 43 passes, which line also passes through the center 44 of the cylindrical chamber and the center 48 of the piston. This contact point is not always the same point on the piston, but changes with the position of the piston, as will be understood. In

.the description when the position of the piston is referred to, it usually refers to the position of the contact point.

The importanceof always having proper relationship between position, tail blade andvalve will be more apparent from the following discussion, particularly withrespect to Figs. 1-5.

As, stated, the piston l4 gyrates in a clockwise direction, as indicated by the arrow. Dead center will be assumed to be position the piston takes when its center is located on a vertical line 41 passing through the center of the, valve cylinder and through the center of the ,main chamber. All angular relationships of the piston, as it sweeps around in its cylinder, will be referred to with respect to upper dead center which is designated as zero degrees. Lower dead center is indicated as 180..

As stated, asthe piston l4 gyrates around in its cylinder, it draws gasin behind it through intake opening l6 and forces gas ahead of, it out through discharge opening l1. It will be noted that-the gasbegins to compress as soon as the piston l4 passes the inlet port. This gasis compressed during the angular rotation of the piston from the inlet portto the valve-opening point (42 in Fig. 1). When the piston [4 reaches the opening point, the valve I5 opens and compressed air is forced into thedischarge ductfl until the piston l4 reaches the closing point. (45 in Fig. 2), at which point the valve 15. closes. The valve l5 remains closed all the while the piston describes the angle from the closing point 45 around to'the opening point again.

It will be notedthat the, closing point 45 is exactly at the lip 22 formed by theintersection of the valve housing and the main cylinder. Thisrelationship is important. It will be noted,

particularly-from Fig. 2, that if thevalve does not close until after the contact point reaches the near edge or lip of the arcuategap, high pressure generated in the high pressure disposition of the valve mustalways beat the lip 2-2, regardless of generated pressure.

In; building a compressor for a given pressure,

the angular position of thecontact point for valve opening, i. e. the valve-opening point (42 in Fig. 1, for example) must first be determined, This may be determined empirically, or by test. Specific examples of the correct anglesfor the valve-opening point for different pressures will be given below."

Astraight line (46 in Fig. ,1) is then drawn between the valve-opening point 42 and the valve-closing point or lip 22. If it is desired to have the-slot for the tail blade 13 pass through the. valve center, a parallel line (41 in Fig. 1) is drawn through the center of thevalve l5.

'It-will' be noted that, in Figs. 1 and 2, this line 41 passes through the center of the piston l4, making the tail blade 13 radial with respect to the piston; this is pure coincidence, as this condition occurs only for the special case where the valve-opening position is at about 203. With the piston in valve-opening position and the radial tail blade passing through the valve center, the valve port [8 will then be cut to such a length as to time valve opening exactly at this point.

The manner of determining the length of valve port [8 for other generated pressures should be clear from the above explanation. In Figs. 3 and 4, the valve-closing point will be at the lip 22, as explained above. The valve-opening point 42 is located at about 230. The line 46 is drawn between these two points. A parallel line 4! is drawn through the valve axis. This parallel line defines the position of the tail blade l3, which is nonradial with respect to the piston. The valve port I8 is cut to just open the valve at this point.

In Fig. 5, the valve-opening point 42 is located at about 210. A line 46 is drawn through point 42 and lip 22. A parallel line ll is drawn through the piston center, which line passes through the valve member I5 at a point oiTset from the valve axis. This line 41 determines the position of the slot through which the tail blade passes. The valve port is then cut to just open the valve at this point.

In Fig. 8, the valve opening point 42 is located at about 220. A line 46 is drawn through point 42 and lip 22. A line All parallel to 46 is drawn, as shown. This line ll passes neither through the piston center nor the center of the valve member.- This line 41 determines the position of the tail blade and also the position of the slot through which the tail blade passes. The valve port I8 is then out to just begin to open the valve at this point.

Ordinarily, variation for compressed gas pressure will be accomplished by properly positioning the tail blade I3 as in Figs. 1, 2, 3, 4, 6 and 7, instead of using the treatment illustrated in Fig. 5 or Fig. 8.

It will be noted that, in any of the above constructions, the valve-opening and valve-closing points of the piston beara definite fixed relationship to each other; this can be better understood by considering a theoretical movement of the piston from one position to the other. That is to say, assuming the piston to be disconnected from its crank pin, and assuming the valve block to occupy a fixed position with the valve just ready to open or close, the piston may be moved between its valve-opening and valve-closing points by simply moving the piston tail blade lengthwise in its slot.

As stated above, there is only one position of the piston at which the valve should close, re-

gardless of generated pressure. This is when the contact point is at the lip 22. There are many positions at which the valve should open,- depending upon the particular pressure for which the compressor is designed. In our tests we found that at 1740 R. P. M. when the valve-opening position is at about 180, the compressor is efficient up-to generated pressures of about 50 pounds gauge; if the valve opens at 215, the best efiiciency is obtained at about 150 pounds gauge generated pressure.

It will be understoodthat liquids other than oil may be used for-sealing and lubricating. Also, the compressor may beused as a vacuum pump; and the compressor may be run as a motor, without change, by applying motive pressure to the discharge duct. Hence, in the claims the use of the term compressor and other terms to describe the compressing function are intended to cover the use of the present invention as a vacuum pump and as a motor, as well as a compressor.

The operation of the compressor is not dependent upon spring pressed check valves which,

by their very nature, are not sufiiciently fast acting for all purposes, at high speeds. This enables the present compressor to be run at higher speeds, tests indicating up to 2000 and even3600 R. P. M.

While certain novel features of the invention have been disclosed herein, and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. A rotary compressor comprising a casing having a main cylindrical chamber, a valve chamber intersecting said main chamber and forming a pair of lips therewith, an eccentrically gyrating piston in said main chamber, an

oscillatory valve member in said valvechamber, a discharge port in the valve member adjacent one of the lips, a tail blade on said piston and integral therewith, said valve member having a slot in which said tail blade reciprocates, said casing having a low pressure inlet duct and a high pressure outlet duct, said inlet duct communicating with said main chamber, said discharge port being adapted to connect said high pressure duct and said main chamber at times and to disconnect said high pressure duct and said main chamber at other times, as the valve member oscillates, characterized in this that the center line of the tail blade has such a position with respect to the center of the piston and with respect to the center of the valve member that, at any selected contact point of the piston with the wall of the main chamber on the compression stroke of the piston, predetermined for the beginning of the opening of the outlet duct, the center line of the tail blade is parallel to a line drawn from said contact point to the' tip of the lip adjacent the discharge port whereby the closing of the outlet duct'is completed when the point of contact of the gyrating piston with the wall of the main chamber reaches the said tip of the lip adjacent the discharge port. I

2. The rotary compressor according to claim 1 in which the center line of the tail blade is oifset from the center of the piston.

3. The rotary compressor according to claim 1 in which the center line of the slot is offset from the center of'the valve member.

4. The rotary compressor according to claim 1; in which the center line of; the. tail blade is 5. The rotary compressor according to claim 1- in which said inlet duct communicates with said main chamber at a point spacedfrom the valve member and from the tail blade.

VADIM S. MAKAROFF. ALEXIS E. JACKSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 751,014 Rein Feb. 2, 1904 1,335,577 Handley Mar. 30, 1920 Num e Number 8 Name Date.

e r v--. ly 24, 1923 raw 3, 9 Brouse S V Aug. 2 1, i928 Knowles, June 24,1947 FOREIGN PATENTS Country Date Great Britain of 1914 r nce ----c-- -v-t--.-- F b- 8, 92 France Feb. 8, 1 921 GreatBrita in Sept. 1 ,1927 Germany Aug. 26, 1924 Germany Oct. 13 1924 Germany, Feb. 18, 1925 Germany Sept. 2 1925

Images