US2578196A - Screw compressor - Google Patents

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Publication number
US2578196A
US2578196A US713342A US71334346A US2578196A US 2578196 A US2578196 A US 2578196A US 713342 A US713342 A US 713342A US 71334346 A US71334346 A US 71334346A US 2578196 A US2578196 A US 2578196A
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Prior art keywords
rotor
housing
rotors
grooves
outlet
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US713342A
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Montelius Carl Oscar Josef
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Imo Industri AB
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Imo Industri AB
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04CROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C18/00Rotary-piston pumps specially adapted for elastic fluids
    • F04C18/08Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C18/082Details specially related to intermeshing engagement type pumps
    • F04C18/088Elements in the toothed wheels or the carter for relieving the pressure of fluid imprisoned in the zones of engagement
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04CROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C18/00Rotary-piston pumps specially adapted for elastic fluids
    • F04C18/08Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C18/12Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
    • F04C18/14Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
    • F04C18/16Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type

Description

Dec. 11, 195] c J MONTELIUS 2,578,196
SCREW COMPRESSOR Filed Nov. 30, 1946 3 Sheets-Sheet 1 IN! 'E.\' TOR.
(arl Oscar Josef [10111611116 Dec. 11, 1951 c. o. J. MONTELIUS 2,578,196
SSSSS SSSSSSSS OR I I 7 INVENTOR.
19 32. 15 arl Oscar Joaef Monielius Patented Dec. 11, 1951 scunw oomrlmssoa Earl Gscar Josef Montelius, Stockholm, Sweden,
assignor to Alt-:tieholaget Hmo-Industri, Stoolshohn, Sweden, or company or Sweden Application November 3d, 1943, Serial No, 713,343
d llllas, (i, 230-ll4ii-l) This invention relates to screw compressors oi the type having a plurality of intermeshing rotors enclosed in a housing and has particular reference to the securing of proper discharge from such a compressor.
in screw compressors the rotors are placed in a housing having inlet and outlet openings, the inside of the housing having intersectin bores to fit the outsldes of the rotors. Contrary to the practice in the case of pumps for incompressible liquids, an end wall of the housing is located against the pressure (outlet) end or the rotors, to compress the volume enclosed in the individual grooves lociore the rotors have reached the rotary position where these grooves open to the outlet. Further: it is a common practice to sup port the rotors by hearings avoid contact ha tween the rotors and the housing and to couple them by gear wheels to avoid direct friction between the screw threads of the intermeshing rotors. The shape of the screw threads is such that one of the cooperating rotors (the male" rotor) is arranged with convex flange sides, the other (the female rotor) with concave flange sides (as in Patents 1,708,891 or 2,321,696) to avoid unnecessary leakage in all positions.
The outlet opening in the housing, which should be placed and dimensioned so that it permlts a discharge at the right moment, when the compression in the grooves has reached a desired value, has been either placed sideways along the circumference of the rotors or in the pressure end wall or both ways. None of these arrangements, however, is satisfactory.
If the outlet is placed only sideways, it will allow the main part of the compressed gas to escape, but a small volume will be entrapped between the rotor threads and the end wall.
If, on the other hand, the outlet is placed in the end wall or so that it opens both sideways and to the end wall, this entrapped volume can escape, but then a direct passage from the out let or high pressure side to the low pressure side cannot be avoided in certain positions of the rotors.
In the present invention a free outlet is arranged only sideways, the end of one oi the cooperating rotors being closed by a valve plate fixed on this rotor with a. necessary clearance with the end wall. In this valve plate passages from each rotor groove are made adjacent to one side of the rotor threads and cooperate with a. channel in the end wall, which is connected to the outlet but covered by the valve plate. This channel is placed in such position that it drains the trapped volume to the outlet.
In the drawings,
Fig. 1 shows a length-wise seotion of a coinpressor according to the invention;
Fig. 2 is an and side viewer the same compressor;
Figs. i and 5 show a section alon the line Jimill in Fig. 1 illustrating the rotors in three diflerent positions; and
Fig. 6 corresponds to Fig. 3, but involves avalve plate fixed upon the male screw instead of the female screw.
lln l. and Fig. 2 the housing is divided in two parts i and 22 secured together by four bolts and nuts indicated at The ends of. the housing are closed. by two end covers 6 and 5. In the housing two rotors and i are supported at one end hy roller hearings t; and at the other end by hall hearings The rotor has a driving shaft it) to be driven by a motor. At the opposite end gear "vheels El and G2 are fixed upon the rotor shafts, coupling them together. The inside of the two parts i and 22 of the housing is machined in the shape of two intersecting bores fitting the cylindrical outside surfaces of the rotors and the end walls of these bores are machined to planes fitting the plane ends of the rotors. The rotors are machined to screw shapes or opposite pitch, the rotor 6 being a male screw with convex flanges, the rotor l a female screw with concave flanges. The housing is further provided with an inlet openin it at one side and an outlet opening it at the other side. In Fig. l the inlet it and the outlet M are indicated by dotted lines.
At the outlet end of the rotor l a plate is fixed upon the rotor. This end plate is and the rotors are further illustrated in Figs. 3, 4 and 5. The female screw TI is designed with four threads l6 and is rotated in the direction indicated by the arrow. Along the back side ll of each thread anoblong opening I8 is cut in the end plate. Along the end wall of the inside of the housing facing the plate a groove or channel I9 is machined formin a. conduit for the compressed gas to the outlet It.
In the operation of the machine the rotor 6 is rotated, driven by the shaft l0 and driving the rotor I by the gear wheels II and Hi. The rotor threads have such a shape that the grooves on both rotors are closed by the threads of the other rotor and by the housing, making a set of closures, which are constantly moving lengthwise from the suction end wall 20 in Fig. 1 to the pressure and wall 2|. These closures are filled by a fluid through the inlet [3 which is compressed during the rotation. In a. certain 3 position the tops of the threads by their rota.- tion reach a position where the closures open to the outlet opening ll. Durin the following rotation the main part of the volume in the 010- sure is expelled through this outlet H.
In Figures 3-5 the rotor ends close to the pressure end wall 2| are illustrated. The rotor groove 22 in the rotor 6 in Fig. 1 is marked by the same number in Fig. 3. This rotor groove opens to groove 23 in the rotor 1 in both Figs. 1 and 3. They form together a closure, which is in this position open to the outlet [4. The following grooves 24 in rotor 6 and 25 in rotor 1 form together another closure with a greater volume. This latter closure is open neither to the inlet, nor to the outlet and its volume will be compressed. The main part of the gas in these rotor closures, for instance 22 and 23, will escape to the outlet [4, but in each case a small part of the gas is trapped in the space 26, when the front face 21 of a flange of the male rotor 6 closes a groove 28 of the female rotor. This trapped volume escapes through the valve opening l8 to the channel I9 in the housing, which opens to the outlet I4.
During the following rotation the position shown in Fig. 4 is reached. The opening I8 is still open to the channel 19, but when the rotors have reached the position in Fig. 5, the opening I8 is shut off from the channel Hi.
It is necessary that the opening I8 is placed only along the back side of the female rotor threads. Otherwise a passage would be created from the outlet I4 and the groove [9 to the back side 29, Fig. 4 and Fig. 5, of the male thread. The crescent-shaped area between the back side 29 and the female front side 30 indicates the beginning of a canal along the rotor threads, widening to the suction side or inlet. If therefore the opening I8 would be too wide and open to this crescent-shaped passage, the compressed fluid would escape this way causing a considerable loss and noise.
The valve plate can be fixed upon the male rotor instead of the female one. In Fig. 6 the arrangement of the passages is illustrated in a position corresponding to that of Fig. 3. The arrangement differs only from that previously described in that the openings 3| in Fig. 6 are placed along the front side 32 of the male screw instead of along the back side of the female screw as was previously described.
rotor cooperate with two or more female rotors.
Each of these female rotors should then be provided with a valve plate according to the invention. It is also possible, when a plurality of female rotors are used, to arrange a single valve plate upon the male rotor.
Having now particularly described the nature of my invention and the manner of its operation what I claim is:
l. A screw compressor including a housing, intermeshing male and female screw rotors within the housing, said housing having inlet and outlet openings, the outlet opening being laterally related to said screws to provide escape for elastic fluid compressed within the rotor grooves, and a valve plate carried by one of said rotors at the compression end thereof, said valve plate having a plane face engaging fiatwise a plane surface on an end wall of the housing, said end wall of the housing having a passage therein providing communication between the region inside the part of the end wall which is within the circumferences of both screws and said outlet opening, and said plate being provided with openings furnishing communication between the rotor grooves and said passage for the escape of elastic fluid entrapped in said grooves after closure of the grooves following their communication with the outlet opening.
2. A screw compressor including a housing, intermeshing male and female screw rotors within the housing, said housing having inlet and outlet openings, the outlet opening being laterally related to said screws to provide escape for elastic fluid compressed within the rotor grooves, and a valve plate carried by the male rotor at the compression end thereof, said valve plate having a plane face engaging fiatwise a plane surface on an end wall of the housing, said end wall of the housing having a passage therein providing communication between the region inside the part of the end wallwhich is within the circumferences of both screws and said outlet opening. and said plate being provided with openings furnishing communication between the rotor grooves and said passage for the escape of elastic fluid entrapped in said grooves after closure of the grooves following their communication with the outlet opening.
3. A screw compressor including a housing. intermeshing male and female screw rotors within the housing, said housing having inlet and outlet openings, the outlet opening being laterally related to said screws to provide escape for elastic fluid compressed within the rotor grooves, and a valve plate carried by the female rotor at the compression end thereof, said valve plate having a plane face engaging fiatwise a plane surface on an end wall of the housing, said end wall of the housing having a passage therein providing communication between the region inside the part of the end wall which is within the circumferences of both screws and said outlet opening, and said plate being provided with openings furnishing communication between the rotor grooves and said passage for the escape of elastic fluid entrapped in said grooves after closure of the grooves following their communication with the outlet opening.
4. A screw compressor including a housing, intermeshing male and female screw rotors within the housing, said housing having inlet and outlet openings, the outlet opening being laterally related to said screws to provide escape for elastic fluid compressed within the rotor grooves, and a valve plate carried by one of said rotors at the compression end thereof, said valve plate having a plane face engaging fiatwise a plane surface on an end wall of the housing, said end wall of the housing having a passage therein providing communication between the region inside the part of the end wall which is within the circumferences of both screws and said outlet opening, and said plate being provided with openings furnishing communication between the rotor grooves and said passage for the escape of elastic fluid entrapped in said grooves after closure of the grooves following their communication with the outlet opening, each opening in said valve plate being adjacent to a side of a thread of the rotor which carries the plate.
5. A screw compressor including a housing. intermeshing male and female screw rotors within the housing, said housing having inlet and outlet openings, the outlet opening being laterally related to said screws to provide escape for elastic fluid compressed within the rotor grooves, and
a valve plate carried by the male rotor at the compression end thereof, said valve plate having a plane face engaging fiatwise a plane surface on an end wall of the housing, said end wall of the housing having a passage therein providing communication between the region inside the part of the end wall which is within the circumferences of both screws and said outlet opening, and said plate being provided with openings furnishing communication between the rotor grooves and said passage for the escape of elastic fluid entrapped in said grooves after closure of the grooves following their communication with the outlet opening, each opening in said valve plate being adjacent to the leading side of a thread of said male rotor.
6. A screw compressor including a housing, intermeshing male and female screw rotors within the housing, said housing having inlet and outlet openings, the outlet opening being laterally related to said screws to provide escape for elastic fluid compressed within the rotor grooves, and a valve plate carried by the female rotor at the compression end thereof, said valve plate having a plane face engaging flatwise a plane surface on an end wall of the housing, said end wall of the housing having a passage therein providing communication between the region inside the 6 part of the end wall which is within the circumferences of both screws and said outlet opening, and said plate being provided with openings furnishing communication between the rotor grooves and said passage for the escape of elastic fluid entrapped in said grooves after closure of the grooves following their communication with the outlet opening, each opening'in said valve plate being adjacent to the trailing side of a thread of said female rotor.
CARL OSCAR JOSEF MONTELIUS.-
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 165,805 Disston July 20, 1875 1,409,868 Kien Mar. 14, 1922 1,708,891 Montelius Apr. 9, 1929 1,994,397 Loveridge et al. Mar. 12, 1935 2,130,054 Whitfield Sept. 13, 1938 2,236,980 Ungar Apr. 1, 1941 2,287,716 Whitfield June 23, 1942 2,321,696 Montelius June 15, 1943 2,460,310 Rathman Feb. 1, 1949
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Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2655309A (en) * 1950-05-01 1953-10-13 J F Nevins Dual rotor compressor
US2656972A (en) * 1949-01-31 1953-10-27 Dresser Ind Adjustable port arrangement for the high-pressure ends of fluid pumps and motors of the rotary screw type
US2705922A (en) * 1953-04-06 1955-04-12 Dresser Ind Fluid pump or motor of the rotary screw type
US2804260A (en) * 1949-07-11 1957-08-27 Svenska Rotor Maskiner Ab Engines of screw rotor type
US2935247A (en) * 1958-12-30 1960-05-03 Atlas Copco Ab Screw-rotor compressor
US3057543A (en) * 1960-02-05 1962-10-09 Ingersoll Rand Co Axial flow compressor
US3097359A (en) * 1963-07-09 Axial compressor
US3209990A (en) * 1962-01-18 1965-10-05 Atlas Copco Ab Two stage screw rotor machines
US3275226A (en) * 1965-02-23 1966-09-27 Joseph E Whitfield Thrust balancing and entrapment control means for screw type compressors and similardevices
DE1281626B (en) * 1958-12-30 1968-10-31 Atlas Copco Ab Screw compressors
US3518975A (en) * 1967-05-09 1970-07-07 Reinhold Schmidt Rotary-piston engine
US3535060A (en) * 1969-03-21 1970-10-20 Arthur E Brown Rotary displacement machines
US4443170A (en) * 1981-11-25 1984-04-17 Sullair Technology Ab Arrangement at oil-injected high-pressure screw compressor
US4556373A (en) * 1984-09-04 1985-12-03 Eaton Corporation Supercharger carryback pulsation damping means
US4569646A (en) * 1984-09-04 1986-02-11 Eaton Corporation Supercharger carry-over venting means
US20070264146A1 (en) * 2006-05-10 2007-11-15 Dieter Mosemann Screw compressor for high input power
US20090148331A1 (en) * 2008-10-28 2009-06-11 592301 Alberta Ltd. Roots type gear compressor with helical lobes having feedback cavity
US20110083647A1 (en) * 2009-10-14 2011-04-14 Hansen Craig N Internal combustion engine and supercharger
US20110083432A1 (en) * 2009-10-14 2011-04-14 Hansen Craig N Internal combustion engine and supercharger
US20110204654A1 (en) * 2005-04-01 2011-08-25 Hansen Craig N Engine and supercharger
WO2011149444A1 (en) * 2010-05-28 2011-12-01 Hansen Craig N Engine and supercharger
US8419399B2 (en) 2008-10-28 2013-04-16 592301 Alberta Ltd. Roots type gear compressor with helical lobes having communication with discharge port
EP2264319A3 (en) * 2009-05-28 2014-05-21 Hitachi, Ltd. Oil free screw compressor
US20140301767A1 (en) * 2013-04-09 2014-10-09 Aura Systems, Inc. Mechanical Interface for an Auxiliary Power Source

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US165805A (en) * 1875-07-20 Improvement m rotary blowers
US1409868A (en) * 1920-08-05 1922-03-14 W M Hardwick Pump
US1708891A (en) * 1924-11-10 1929-04-09 Montelius Carl Oscar Josef Rotary engine for compressible or expansive mediums
US1994397A (en) * 1933-03-23 1935-03-12 Loveridge Claude Warren Rotary engine
US2130054A (en) * 1935-07-02 1938-09-13 Joseph E Whitfield Blower
US2236980A (en) * 1937-12-02 1941-04-01 Joseph F Keller Liquid pump or motor
US2287716A (en) * 1941-04-22 1942-06-23 Joseph E Whitfield Fluid device
US2321696A (en) * 1940-02-06 1943-06-15 Imo Industri Ab Screw rotor
US2460310A (en) * 1943-11-20 1949-02-01 Roots Connersville Blower Corp Screw pump

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US165805A (en) * 1875-07-20 Improvement m rotary blowers
US1409868A (en) * 1920-08-05 1922-03-14 W M Hardwick Pump
US1708891A (en) * 1924-11-10 1929-04-09 Montelius Carl Oscar Josef Rotary engine for compressible or expansive mediums
US1994397A (en) * 1933-03-23 1935-03-12 Loveridge Claude Warren Rotary engine
US2130054A (en) * 1935-07-02 1938-09-13 Joseph E Whitfield Blower
US2236980A (en) * 1937-12-02 1941-04-01 Joseph F Keller Liquid pump or motor
US2321696A (en) * 1940-02-06 1943-06-15 Imo Industri Ab Screw rotor
US2287716A (en) * 1941-04-22 1942-06-23 Joseph E Whitfield Fluid device
US2460310A (en) * 1943-11-20 1949-02-01 Roots Connersville Blower Corp Screw pump

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3097359A (en) * 1963-07-09 Axial compressor
US2656972A (en) * 1949-01-31 1953-10-27 Dresser Ind Adjustable port arrangement for the high-pressure ends of fluid pumps and motors of the rotary screw type
US2804260A (en) * 1949-07-11 1957-08-27 Svenska Rotor Maskiner Ab Engines of screw rotor type
US2655309A (en) * 1950-05-01 1953-10-13 J F Nevins Dual rotor compressor
US2705922A (en) * 1953-04-06 1955-04-12 Dresser Ind Fluid pump or motor of the rotary screw type
US2935247A (en) * 1958-12-30 1960-05-03 Atlas Copco Ab Screw-rotor compressor
DE1281626B (en) * 1958-12-30 1968-10-31 Atlas Copco Ab Screw compressors
US3057543A (en) * 1960-02-05 1962-10-09 Ingersoll Rand Co Axial flow compressor
US3209990A (en) * 1962-01-18 1965-10-05 Atlas Copco Ab Two stage screw rotor machines
US3275226A (en) * 1965-02-23 1966-09-27 Joseph E Whitfield Thrust balancing and entrapment control means for screw type compressors and similardevices
US3518975A (en) * 1967-05-09 1970-07-07 Reinhold Schmidt Rotary-piston engine
US3535060A (en) * 1969-03-21 1970-10-20 Arthur E Brown Rotary displacement machines
US4443170A (en) * 1981-11-25 1984-04-17 Sullair Technology Ab Arrangement at oil-injected high-pressure screw compressor
US4556373A (en) * 1984-09-04 1985-12-03 Eaton Corporation Supercharger carryback pulsation damping means
US4569646A (en) * 1984-09-04 1986-02-11 Eaton Corporation Supercharger carry-over venting means
US8256403B2 (en) 2005-04-01 2012-09-04 Hansen Engine Corporation Engine and supercharger
US20110204654A1 (en) * 2005-04-01 2011-08-25 Hansen Craig N Engine and supercharger
US20070264146A1 (en) * 2006-05-10 2007-11-15 Dieter Mosemann Screw compressor for high input power
US7618248B2 (en) * 2006-05-10 2009-11-17 Grasso Gmbh Refrigeration Technology Screw compressor with intermediate plate
US20090148331A1 (en) * 2008-10-28 2009-06-11 592301 Alberta Ltd. Roots type gear compressor with helical lobes having feedback cavity
US8419399B2 (en) 2008-10-28 2013-04-16 592301 Alberta Ltd. Roots type gear compressor with helical lobes having communication with discharge port
US8096797B2 (en) 2008-10-28 2012-01-17 592301 Alberta Ltd. Roots type gear compressor with helical lobes having feedback cavity
EP2264319A3 (en) * 2009-05-28 2014-05-21 Hitachi, Ltd. Oil free screw compressor
US20110083432A1 (en) * 2009-10-14 2011-04-14 Hansen Craig N Internal combustion engine and supercharger
US20110083647A1 (en) * 2009-10-14 2011-04-14 Hansen Craig N Internal combustion engine and supercharger
US8539769B2 (en) 2009-10-14 2013-09-24 Craig N. Hansen Internal combustion engine and supercharger
US8813492B2 (en) 2009-10-14 2014-08-26 Hansen Engine Corporation Internal combustion engine and supercharger
WO2011149444A1 (en) * 2010-05-28 2011-12-01 Hansen Craig N Engine and supercharger
US20140301767A1 (en) * 2013-04-09 2014-10-09 Aura Systems, Inc. Mechanical Interface for an Auxiliary Power Source

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