US2719002A - Compressor - Google Patents

Description

F. A. GLOMB 2,719,002

COMPRESSOR 3 Sheets-Sheet 1 Sept. 27, 1955 Filed May 29, 1950 INVENTOR FRANK A. GLOMB Sept. 27, 1955 F. A. GLOMB 2,719,002

COMPRESSOR Filed May 29, 1950 5 Sheets-Sheet 2 W\ a 23 gg u IN VEN TOR.

' FRANK A. GLOMB Sept. 27, 1955 GLOMB 2,719,002

COMPRESSOR Filed May 29, 1950 3 Sheets-Sheet 3 INVENTOR. HPANK A. GLOMB M am, W

United States Patent COMPRESSOR Frank A. Glornb, Park Forest, 111., assignor to Barnes & Reinecke, Inc., Chicago, 111., a corporation of Delaware Application May 29, 1950, Serial No. 165,090

' 4 Claims. ((31. 230-172) My invention relates to an improved compressor and inlet and delivery structures for use therein characterized by high volumetric efliciency, small leakage, simplicity of construction, low energy loss and ability to operate at high piston velocity, and at the same time have a high compression ratio.

Piston type compressors inherently involve some residual volume of fluid which is not driven from the compressor during the stroke of the piston. This residual volume is undesirable because the fluid contained in that volume is worked upon by the piston and yet is not delivered to the high pressure manifold. It is furthermore undesirable because it prevents the compressor from effectively utilizing its full suction strike, suction not taking place until this residual Volume has expanded back to intake pressure. Moreover, in compressors of the piston type, it is highly desirable to provide inlet and outlet valve mechanisms that operate in accordance with the piston movements with a minimum time delay so that the quantity of 'back flow and energy lost thereby is minimized. Rapid valve response also minimizes the pressure gradient that accumulates during the time the valves are opening. In addition to the foregoing it is desirable in a compressor to provide intake and outlet ports and associated valve mechanisms that define large capacity streamlined fluid passages giving rise to minimum eddy loss and pressure drop.

The foregoing considerations are particularly acute in the case of compressors operating at high piston speeds for such compressors require correspondingly high intake and delivery air velocities. Compressors with high piston speed have the important advantage of high output in proportion to their size and weight.

In accordance with the present invention an improved compressor is provided which has large, streamlined intake and outlet passages in which the various fluid streams flow parallel to each other with minimum mixing and eddy loss. Moreover, very thin light weight fluid operated valves are utilized in conjunction with backup or stop members which arrest motion of the valves without imposing bending stress upon them. These valves cover ports of relatively large area so that limited motion of them provides ample inlet area. Moreover, the compressor of the present invention utilizes a cylinder head construction wherein a relatively thin plate defines the outlet ports and carries relatively thin fluid operated outlet valves. A reinforcing backup plate in spaced relation to the first plate sustains the same against the cylinder pressure and at the same time forms a stop surface to arrest the motion of the valves without creating substantial bending stress on them.

It is therefore a general object of the present invention to provide an improved compressor characterized by high operating efficiency.

A more particular object of the present invention is to provide an improved compressor having minimum residual volume.

Another object of the present invention is to provide an improved compressor and valve structure for use 2,719,002 Patented Sept. 27, 1955 therein wherein fluid passages of maximum size for intake and outlet flow are provided.

Still another object of the present invention is to provide an improved compressor and valve structure for use therein wherein intake and outlet flow takes place with minimum eddy flow.

Yet another object of the present invention is to provide an improved compressor and valve structure for use therein wherein the valves operate in response to the piston movements with a minimum time delay to the end that back flow and unnecessary pressure buildup is minimized.

My invention further resides in providing an improved compressor and valve structure thereby having features of construction combination and arrangement wherein a high degree of simplicity, reliability, and ruggedness is obtained and at the same time maximum operating efficiency is achieved even at high piston speed.

The novel features which I believe to be characterized by my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

Figure l is an axial cross-sectional view of a complete compressor constructed in accordance with the present invention;

Figure 2 is a cross-sectional view on section line 22, Figure 1;

Figure 3 is a fragmentary cross-sectional view on section line 3-3, Figure 1;

Figure 4 is an. enlarged fragmentary cross-sectional view on section line 4-4, Figure 3;

Figure 5 is a fragmentary cross-sectional view on section line 5-5, Figure 1; and

Figure 6 is a fragmentary cross-sectional view on section line 6-6; Figure 2.

Figure 7 is a fragmentary cross-sectional view on section line 77; Figure 2.

Figure 8 is a fragmentary cross-sectional view on section line 88; Figure 3.

Referring now to Figure 1, there is shown generally at 10 the cylinder block of a piston type compressor. This block defines a plurality of annular surfaces 12 which mate with and receive the cooperating external surfaces of the sleeve 14 which defines a cylinder within which the piston'16 fits. An intermediate plate 18 fits over and mates with the top surface of block 10 and the annular surface 14a of the sleeve 14. A cylinder head 20 fits over the intermediate plate 18 to define a complete cylinder in conjunction with the sleeve 14 and the inner cylindrical face 18a of the intermediate block 18. The head 20 and the intermediate block 18 are held in place by the studs 22 and the cooperating nuts 24.

The sleeve 14, block 10, intermediate block 18, and the head 20 cooperatively define intake passages to the cylinder. The block 10 defines an annular intake manifold 26 which communicates with the coupling pipe 28 which receives the end of the inlet pipe for air or other fluid to be compressed. From the manifold 26, the air passes through the annular series of passageways 30 (Figure 5) into the relatively flat or disk shaped submanifold 32. As indicated, this manffold is defined by the top of the block 10, the outer conical face 14b of the sleeve 14, and the lower face of the intermediate block 18.

The ceiling of the flat sub-manifold 32 has three sets of circular inlet passages or ports, the ports of the respective sets being indicated at 34, 36, and 38 respectively. Each port extends entirely through the intermediate block 18 to open on one step or land of the stepped upper face of that member. This face is covered by the cylinder head to define the stepped inlet passage described in further detail hereafter.

The ports 34, 36, and 38 are closed or opened in accordance with the movements of the piston 16 by annular valves 40, 42, 44, respectively. These valves are of annular shape and have rectangular cross-section as seen in Figure 1. Each valve seats snugly on the fiat annular land or seat extending around each step of the auxiliary member 18 so that when the pressure in the inlet passage 46 exceeds the pressure in the chamber 32 the valves rest snugly over the respective ports to prevent back flow of air.

Eight equally spaced radial ribs or wings 54, Figure 3, depend from the head 20 and have a stepped configuration to mate with the stepped upper surfaces of the interme diate block 18.

When the pressure in sub-manifold 32 exceeds the pressure in the passage 46, the valves 40, 42, and 44 are lifted to expose the ports 34, 36, and 38, thereby permitting flow of air into the passage 46 and into the cylinder.

In accordance with one feature of the present invention, the motion of the valves 40, 42, and 46 is arrested by the annular stop plates 48, 50 and 52, respectively. These plates are bonded or otherwise attached to the depending radial wings 54, Figure 3, formed on the cylinder head 20. Each of the valves is made of relatively thin light weight metal but, since the overlaying stops engage the full area of each valve, no bending stress is produced when the upward motion is arrested and consequently there is no undue flexure of the valves.

Each of the stops 48, 50, and 52 is cut out in the region under each wing 54 to prevent interference with the spiral springs 56 provided to urge the valves to the seated condition. These springs are received in the cups 59 formed by upwardly extending bores in the ribs. Each bore is aligned with the corresponding valve and forms a seat for one spring.

As shown in Figures 1, 3, and 4, the upper face of the intermediate block 18 is formed in three annular steps. The ports 38 open into the first step and the ports 36 and 34 open into the second and third steps, respectively. Moreover, the top surface of the stop 52 is about level with the second step and the top of stop 50 is about level with the third step. Consequently, the tops of these stops form a relatively continuous surface across which air can travel radially inwardly into the cylinder.

As shown in Figures 1 and 4, the walls defined by the successive steps of the member 18 are cupped as indicated at 58. This defines a surface adjacent the radially outward side of each valve to direct the issuing air radially inwardly (the downstream direction). This is seen best in Figure 4 where the air flow lines have a velocity component in the radial inward, downstream, direction.

As shown in Figure 4, the air flow from the cupped surfaces adjacent the valves 42 and 44 joins the inwardly directed air stream from the valves 40 and 42, respectively. However, since the direction of fiow of the air flow 60 is substantially parallel to the air that it joins, the streams join without undue eddy flow and the energy loss from such eddy flow is minimized.

As seen best in Figure 4, each of the stop plates 48, 50, and 52 has an overhanging portion 48a, 50a, and 52a at its outer periphery. This portion of the stop extends downwardly to define a conformation to receive the corresponding valve to define a relatively smooth inner surface for the passage defined in conjunction with the corresponding cupped face 55. The flow of air through this passage is further facilitated by the curved outer face of each overhanging portion 480, 50a, and 52a.

The eddy flow energy loss associated with passage of air through the passage 46 is further reduced by the heights of the respective steps to give approximately the same flow velocity at each level. In other words the height of each step is approximately in proportion to the quantity of air intake through the corresponding valve. As a consequence of this construction the pressure gradient along each flow path is nearly the same as the corresponding pressure gradient in the adjacent flow paths and there is little tendency for the streams to mix.

The cylinder head 20 has a central portion 20a extending over the top of the cylinder. As seen in Figure 2 this portion consists of a spider having six ribs 21 spaced at equal angular increments. Outboard of this portion, the head 20 forms an annular seat 20b which mates with and receives the mating annular seat of the delivery air manifold 62. The latter defines a chamber 64 into which air is delivered.

A relatively thin valve plate 100 is positioned below portion 20a of the head 20. This plate has conformations seating against and mating with the circular seat 20c formed in the head 20 immediately below portion 20a. Plate 100 is secured in position by bolts 88 which are threadedly received therein and by nuts 90 which extend through and bear against the top of ribs 21 to draw up the plate 100.

Plate 100 of the head 20 has four series of holes, each series being in annular configuration. The holes of the four series are indicated at 66, 68, and 72 respectively, in Figures 1 and 2. The top face of the plate 100 is smooth adjacent each hole to define four annular seats which receive the four mating annular valves 74, 76, 7S, and as shown.

The plate 100 is reinforced by the spider portion 20a of the head 20 which is mounted above plate 100 and in spaced relation with the upper face thereof. As seen in Figures 1 and 2, the central hub of the spider portion 20a is afiixed at its center to the plate 100 by the stud 84 and nut 86. The spider is also anchored to the plate 100 near its periphery by the six studs 88 which receive the nuts 90 as shown.

As seen best in Figure 2, each arm 21 of the spider 20a has a plurality of cups 82a, one hole disposed in registry with each annular valve 74, 76, 78, and 80. These cups face downwardly and receive the springs 92 which seat against the bottom of each cup and the corresponding valve to urge the valve to a seated position against the plate 100. These springs are of the spiral ribbon type as shown in Figure l.

A boss 21a is formed on each spider arm 21 in the region between the valves 74 and 76. Each boss is of generally rectangular shape and in conjunction with the other like bosses confines the valves 74 and 76 to registered positions relative to the series of holes 72 and 70, respectively. Similar bosses 21b are formed on each spider arm between the valves 78 and 80 and confine these valves to positions in registry with the ports or holes they cover.

A series of annular webs 23 extend between the arms 21 of spider 20a as shown in Figure 2. These define annular stop surfaces which arrest the opening motion of the valves 74 to 80, and are of generally V-shaped crosssection as shown in Figure 6 to form relatively rigid stop faces. The bottom of each web 23 is flat to engage the corresponding valve without creating any bending stress.

The under side of the plate is cupped at 100a to receive a corresponding protuberance 16a on piston 16. This minimizes the residual volume in the cylinder when the piston is at the top position. Since the plate 100 is rigidly supported from the portion 20a of the cylinder head 20 at its center and at its periphery, it forms a truss in conjunction with head 20 and acts as a relatively rigid body.

The valves 74 to 80 are of relatively thin light Weight construction. This construction can be used since the stops defined by the webs 23 engage substantially the entire surfaces thereof to arrest opening motion without creating significant bending stress.

In operation of the compressor of the present invention, the annular valves 40, 42, and 44 open very quickly when the piston down stroke starts. Valves 74 to 80 execute like quick closing motions. This closes off the delivery manifold 64 and opens the passages to the intake manifold 30. The piston thus draws air into the cylinder. When the piston subsequently starts its upward motion, the valves 40 to 44 execute like rapid closing motions and the valves 74 to 80 thereafter open as soon as the air pressure within the cylinder exceeds the air pressure in the manifold 64. It will be observed that with this structure the flat annular valve design can be used and opening and closing time is reduced to a minimum relative to the area opened by the valve. This is achieved by making the ratio of thickness of the valve plate to its pressure area very small. Correspondingly, the ratio of the weight of the valve and the net pressure force urging it to the open or closed position becomes very small, thus giving high values of accelerating and correspondingly high velocity valve motion. Since the total valve travel distance is very small, short valve opening and valve closing times are achieved. When the valves 74 to 80 open, a relatively large delivery passage area is defined and the piston works against substantially constant delivery pressure for the remainder of the stroke.

It will be observed that the residual volume when the piston is in the up position is the space defined by the relatively short ports 66, 68, 70, and 72, the clearance space between the piston and head 20, and the volume of the stepped chamber 46. This is a relatively small space particularly in relation to the relatively large cross-sectional areas of the intake and delivery air passages. In a compressor designed in accordance with the present invention, for example, a clearance volume of only 8 per cent was required while at the same time it was possible to keep the maximum air velocity down to approximately four times the maximum piston speed.

Moreover, since the spaced levels or strata of air flow in the stepped passage 46 flow at substantially the same velocity, the tendency for eddy flow is minimized, thus minimizing the pressure required to produce the flow. This pressure is further reduced by the flow directing cupped faces 58 between the steps and the streamlined surfaces defined by the mating valves 40, 42, and 44 and stops 48, 50, and 52, respectively.

A passage 94 is formed between the intermediate portion of the sleeve 14 and the cylinder block 10. A finned member 96 is positioned in this passage and cooling air driven therethrough by suitable blowing means (not shown).

The valves 40, 42, 44, 74, 76, 73, and 80 are made as thin as possible to achieve minimum inertia. Since the main bending stress on each valve associated with operation is the stress associated with the back pressure resisted, and this pressure operates only over the relatively small diameter port openings, it is possible to use a very light construction. In an actual compressor design these valves are of stainless steel, 7 inch wide, 0.04 inch thick, and move approximately 0.05 inch from the closed to open position.

While I have shown and described a specific embodiment of my invention, it will of course be understood that I do not wish to be limited thereto since many modifications and alternative constructions may be made without departing from the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a piston type compressor, means defining a cylinder adapted to receive a piston, a laterally-extending intake passage provided by said means in communication with the cylinder through the side walls thereof and having its cross-sectional area stepped in accord with distance from the cylinder, said passage narrowing due to said steps with increasing distance from said cylinder, ports in communication with the intake passage opening through the surfaces of a plurality of the steps that form a side of said intake passage, and valves operable to open and close the ports adapted to operate in sequence with piston movements, the steps in cross section area of the intake passage being dimensioned and arranged to provide substantially uniform fiow velocity and pressure gradient in the air streams through the passage.

2. In a piston type compressor, means defining a cylinder adapted to receive a piston, a laterally-extending circumferentially-disposed intake passage provided by said means in communication with the cylinder through the upper end portion of the side walls thereof and having its cross-sectional area stepped in accord with distance from the cylinder, said passage narrowing due to said steps with increasing distance from said cylinder, ports in communication with the intake passage opening through the surfaces of a plurality of the steps that form a side of said intake passage, relatively thin light weight valves adapted to seat on the openings of the ports, yieldable means biasing the valves to the closed position, said first means defining stops operable to engage the valves over substantially their entire area to arrest motion thereof without creating bending stress.

3. In a piston type compressor, means defining a cylinder adapted to receive a piston, a laterally-extending, circumferentially-disposed intake passage provided by said means in communication with the cylinder and having its cross-sectional area stepped in accord with distance from the cylinder, said passage narrowing due to said steps with increasing distance from said cylinder, ports in communication with the intake passage opening through the surfaces of a plurality of the steps that form a side of said intake passage, relatively thin light weight valves adapted to seat on the openings of the ports, yieldable means biasing the valves to the closed position, and a fixedly supported stop plate overlaying at least one valve to engage the same over substantially its entire area to arrest motion thereof without creating bending stress, the upper surface of the plate being in substantial alignment with the adjacent step of the passage.

4. A valve structure for simultaneously introducing a plurality of streams of gas into a chamber with a minimum of mixing and eddy loss, comprising a manifold providing a passage extending toward said chamber and terminating in an enlarged outlet opening communicating with said chamber, said passage having at least one of its walls extending towards said chamber provided with a plurality of steps arranged to progressively increase the cross-sectional area of said passage toward said outlet opening, the upper surface of said steps being generally parallel and in alignment with said outlet opening, at least one inlet port communicating with said passage through the upper surface of each of said steps, and a valve member associated with each of said inlet ports and arranged to defiect the streams of gas entering said passage through said inlet ports into generally parallel streams moving toward said outlet opening.

References Cited in the file of this patent UNITED STATES PATENTS 1,001,305 Rix Aug. 22, 1911 1,080,322 Brown Dec. 2, 1913 1,614,124 Hansen Jan. 11, 1927 1,939,801 Wells Dec. 19, 1933 1,996,762 Halleck Apr. 9, 1935 2,089,630 Teeter Aug. 10, 1937 2,109,541 Le Valley Mar. 1, 1938 2,147,767 Crosley Feb. 21, 1939 2,193,123 DesRoches Mar. 12, 1940 2,215,017 Schmitt Sept. 17, 1940 2,297,942 Collins Oct. 6, 1942 2,506,751 Trask May 9, 1950 FOREIGN PATENTS 103,173 Australia Feb. 2, 1938 604,968 Great Britain July 13, 1948

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