US3506380A - Self-regulating,automatic rotary vane device and system - Google Patents

Description

SFLF-REGULATING, AUTOMATIC ROTARY VANE DEVICE AND SYSTEM Filed Au 22, 1968 H. H. POWELL April 14, 1970 3 Sheets-Sheet 1 lllll lll ll lllr l lllllllll.

HOWARD H. POWELL INVENTOR.

BY W

FIG.

ATTORNEY April 14, 1970 H. H. POWELL SFLF-REGULATING AUTOMATIC ROTARY VANE DEVICE AND SYSTEM Filed AugQ 22, 1968 5 Sheets-Sheet 2 EVAPORATOR llllllllll CONDENSER FIG. 2

HOWARD H. POWELL INVENTOR.

BYMW/ ATTORNEY April 14, 1970 H. H. POWELL 3,506,380

SFLF-REGULATING, AUTOMATIC ROTARY VANE DEVICE AND SYSTEM Filed Aug. 22, 1968 3 Sheets-Sheet 5 HOWARD H. POWELL INVENTOR.

BY MM ATTORNEY United States Patent Office 3,506,380 Patented Apr. 14, 1970 3,506,380 SELF-REGULATING, AUTOMATIC ROTARY VANE DEVICE AND SYSTEM Howard H. Powell, Fort Worth, Tex.

(1206 John Reagan, Benbrook, Tex. 76126) Continuation-impart of application Ser. No. 606,686, Jan. 3, 1967. This application Aug. 22, 1968, Ser.

Int. Cl. F04c 17/00, 29/08 US. Cl. 417220 5 Claims ABSTRACT OF THE DISCLOSURE A system for a pump of the progressive geometric movement rotary vane type, the pump having vanes radiating from the center of the vane race, the rotor being moveably positioned eccentrically in the casing bore and having provisions for the vanes extending therethrough to progressively vary their angular relationship to the rotor and to each other so that the compression ratio is controlled by the movement of the casing, the rotor displacement or eccentricity is controlled by either the pressure buildup or temperature of the refrigerant through a preset tensioning means, so that no clutch or re-cycling valve is required. The construction is applicable to high speed, high pressure pneumatic devices.

This application is a continuation-in-part of my copending application Ser. No. 606,686, filed Jan. 3, 1967, now abandoned.

This invention relates generally to an improved system for compressors.

More specifically, the invention is drawn to a system utilizing a vane type pump wherein the vanes radiate from the true center of the vane race and are so constructed that the displacement and resultant efficiency of the unit are materially increased through making the included angle between adjacent vanes larger in the low pressure, large volume portion between the rotor and the casing while that between the adjacent vanes in the high pressure, small volume portion diminishes.

THE PRIOR ART Of the many vane types of rotary pumps and motors in use, the most common design is probably the sliding or guided vane type wherein a rotor provided with a number of vanes is mounted eccentrically within the casing bore which serves as a vane race. The vanes slide in slots in the rotor and are caused to maintain contact with the race by centrifugal force or other means. The vanes are made as light as possible'and of abrasive resistant material to keep the centrifugal force required to a minimum. Since these vanes cannot be made to fit the vane race with any degree of accuracy, there is only a relatively light line contact or seal, which offers only a low resistance to leakage. This obviously limits the pressure capacity of the pump. They are therefore used primarily for small or moderate capacities and low speeds and low pressures. For this reason, this type of pump is not considered to be a practical design for pneumatic compressors.

Another type often employed is the so called swinging vane pump. In this construction, the vanes are hinged or articulated to permit them to swing in order that they may swing and adjust to the varying radius of the vane race. Obviously, such a construction imparts deleterious characteristics to the ability of the blades to seal against the vane race because of their inherent, light line contact. This construction lends itself even less to a satisfactory or efiicient seal than does the previously described sliding vane type, and are useful primarily for moderate volumes and low pressure-low speed.

Because of these inherent limitations, the prior art has often had to utilize series of such devices to be able to achieve the pressures it has desired, with an obvious loss in efiiciency.

The closest approach to the pump of the present invented system employs a progressive geometric movement, rotary vane pump, but must depend on external hydraulic means and linkages to vary displacement.

It is an object of the present invention to obviate these and other deficiencies of the prior art by providing a more practical system not heretofore attainable.

It is a further object of the present invention to provide a pump as a pneumatic compressor for gases capable of operation at both high speed and pressure and having a high degree of efficiency.

It is yet another object of the invention to provide a progressive geometric movement rotary vane device wherein the vanes radiate from the center of the casing bore, the rotor being mounted eccentrically within the bore and being provided with rocking spacers whose centers are pivots through which the vanes extend, thus permitting individual vanes of adjacent pairs of vanes to vary their angular relationship one to another, and employing high and low pressure-side demand responsive control means so that the system is self-regulating through its own system fluid.

The rotor and vanes together constitute the impeller. Since the center of the bore of each of the vane slots is a pivot point, as the impeller rotates, the center of the vanes and center of the rotor being offset, the spacers are caused to slide up or down their respective vanes, at the same time rocking or rotating in order to accommodate or adjust to the changing angle of the vane relative to the center of the rotor, the displacement of the rotor responsive to the control means determining both the quantity and pressure of the system fluid.

Since the angle of each vane is fixed in relation to the center of the rotor, the included angle between the two vanes in the outer lobe of the eccentric increases while that of the two vanes in the inner or lower lobe decreases, the angular difference between the vanes developed by the changing angles being a major consideration in calculating displacement.

Other objects and many attendant advantages of this invention will become apparent to those skilled in the art upon consideration of the following description wherein a preferred constructional configuration of the invented device, employed as a variable capacity refrigeration compressor, is disclosed, when taken in conjunction with the drawings wherein:

FIGURE 1 is an isometric view partially in section, with portions thereof broken away and showing the construction of the compressor; and

FIGURE 2 is an elevational view, partially in section, of the pump of FIGURE 1 in relation to the control system.

FIGURES 2A and 2B are sections through the compressor.

Referring first to FIGURE 1, and compressor 10 constructed according to the present invention comprises a housing 12 having side walls 14 and 16 forming an enclosure for casing member 18, which includes side plates 20 and 22, the members 18, 20, 22 forming race 24 on the inside surface of the casing bore.

A drive shaft 26 extends through housing side wall 16 which wall includes extension 28 having bearings 30 journaling drive shaft 26 therein. Integral with shaft 26 is rotor 32, shaft 26 and rotor 32 being mounted eccentrically within casing bore 34 so that the low point on the periphery of rotor 32 slidingly contacts the corresponding low point of casing bore 34, forming an upper lobe 36 having a large volume relative to the opposite lobe. Rotor 32 has the central portion thereof bored out so that it forms a recess having an interior surface 38, the surface 38 having a diameter which is suflicient to clear the vane bearings when rotating in their eccentric position.

Casing side plate 20 is provided with a spindle 40 having a positioning head (not shown), spindle 40 being located at the geometric center of casing bore 34 so that the axis 42 of spindle 40 and axis 44 of (llflVC shaft 26 are offset. Journaled upon spindle 40 are a plurality of vanes 46, 48, 50 and 52 extending outwardly from spindle 40 and consequently forming radii from the center 42 of casing bore 34 to the race 24.

Rotor 32 is provided with vane slots 54 which are spaced equidistantly around the rotor and at equal distance from the center of the rotor, which coincides with the axis 44 of shaft 26. These slots are bored horizontally through the rotor, the diameter of the bore being sufficient to open slot 54 through which the vanes extend. Each vane slot is provided with spacers 62, 64 which have an outside diameter or surface corresponding to the diameter of the bored slot, the interior of the spacers 62 and '64 being smooth and flat to correspond with the sides of the vanes extending therethrough. This construction permits the vanes to change their angularity with respect to each other and to the rotor without binding, the change in angularity being occasioned by the movement of the casing in relation to the rotor.

The housing has extended therethrough inlet 70 (FIG- URE 2) from the cooling coils 210, which inlet communicates with ports 72 extending through casing 18, which ports the low pressure gas into the interior or low pressure side 74 of casing 18. The pump is also provided with outlet line 76 to carry the pressurized vapor from the pump to the condenser 200 (FIGURE 2). Following compression within casing 18, the pressurized vapor is ported through ports 78 into passageway 80, and then into outlet line 76.

As shown in FIGURE 1, and specifically in relation to the system in FIGURE 2, the impeller portion of the pump 10, constituting the housing 12, casing 18, vanes 46, 48, 50 and 52, and rotor 32, are responsive to the regulating means 82, which comprises a receiver housing '84, which housing has inlet 86 to receive liquid from the condenser 200, which liquid flows into plenum 88. Within the housing there is provided a fixed support 90 which supports and positions bellows thermostat 92, thermostat 92 is responsive to temperature differentials within the housing 84, causing it to expand when the liquid from the condenser 200 is relatively hot and to contract the liquid is relatively cold. Yoke member 94 is positioned around thermostat 92, and through adjustable means such as the screw 96 shown, is responsive to expansion of the thermostat, the positioning of adjustable means 96 determining the starting pressure at which the pump unit will begin to pump. Yoke 94 imparts a variable tension to pressure control spring 98, that is, tension spring 98 is caused to increase or decrease as yoke 94 moves up or down responsive to the temperature. Draw-bar 99 is fixedly attached to casing 18 and extends from the receiver through housing 12 and the base of yoke 94, there being sufficient room between the upper end of draw bar 99 and its adjusting means to permit full upward movement of casing 18. As second spring 102 (FIGURE 2) fitting around drawbar 99 and inside spring 98 leans against housing 12, also passing through the base of yoke 94, and against the draw-bar adjusting and retaining means in the other. It is apparent that such a spring may be pre-set to an optimum tension, and furnish the necessary tension to the draw-bar to exert against the casing. As is apparent, the casing 18 is caused to ride up or down dependent on the demand, and when in the up position shown in FIGURES 1 and 2, will remain in that position until the compression pressure forces it downwardly, by overbalancing the tension of the inner spring 102 and spring 98, at which time the springs will permit the casing to move downwardly, carrying with it the vanes. When the center of rotation or axis 42 of the vanes and the casing, and the center of rotation or axis 44 of the rotor are substantially coincident, although the impeller continues to rotate and maintain a pressure field, it stops cycling. However, when a warm refrigerant enters receiver '88, bellows thermostat 92 expands, causing yoke 94 to ride up, the base of yoke 94 compressing spring 98 (but not the inner spring 102) pulling up on draw-bar 99 and causing casing 18 to become eccentric again, thus causing the compressor to work until the condition is overcome. How hard the compressor works is dependent on the expansion of thermostat 92 and the time lapse until the liquid refrigerant entering the receiver cools down. This is a very material advance over the prior art, wherein such compressors of necessity have to depend on outside fluid systems to decrease or increase eccentricity, such as shown in the system of Blackman Patent No. 2,942,774. With the system of the present invention, the pump is caused to work only to meet the need or condition which it encountered at that time, i.e., an automatic condenser has been provided which works no more than the system requires at the given time.

Obviously, many modifications of the above will be apparent to those skilled in the art, and may include a thermostat controlled valve (FIGURE 1) in the upper section of the housing 12, having a passageway 100 from the receiver chamber 88 to a recessed portion 102 between the impeller housing and the casing, the thermostat being preset to open in response to engine (pump) heat and bleed liquid refrigerant from receiver 84 into the housing recess 102, thus obviating any heat build-up within the impeller section from friction or other causes, and permitting the impeller portion to attain maximum efficiency. Obviously, it is also possible within the state of the art to make any of the automatic adjusting means variable or controllable from the outside.

In the functioning of the present invention as shown, the starting pressure is adjusted through means 96. Liquid from condenser 200 flows into receiver 84. Since the spring 98 is normally expanded, and bellows 92 contracted, the casing 18 is normally held against the upper portion of housing 12 by the tension of the draw-bar spring 102. Bellows 92 expands upwardly in response to the warm liquid flow into receiver 84, causing yoke 94 to ride upwardly and thus compressing spring 98, causing casing 18 to be pressed harder against the upper portion of housing 12 through draw-bar 99 fixed to the casing. At the same time, gas from the evaporator 210 enters casing 18 through inlet 70 in housing 12, then through ports 72 into the plenum in the upper portion 36 of the lobe of casing bore 34. Since both rotor 32 and vanes 46-52 are rotating, each vane creates its own compression stroke, the compression of the volume of the gas within any of the sectors between vanes in the upper portion of the race progressively increasing as the volume becomes smaller due to the off center or eccentric positioning of the rotor 32. By the time the compressed volume has approached the bottom portion or highv pressure side of the casing bore, it has built up enough pressure to overcome the resistance imparted to the casing .18 by draw-bar spring 102 and spring 98 responsive to thermostat 92 (provided the thermostat is expanded), thus causing the casing to move downward slightly, the pressurized gas entering ports 78 into cell 80, the pressure opening one way valve 104 and permitting the compressed vapor to enter outlet 76 to the condenser 200. This action occurs for each vane, although so rapidly in this type of compressor that there is little .return movement of the casing 18, and as the cooler liquid is re-cycled from condenser 200 to the receiver, the bellows 92 acting responsive thereto contracts downwardly on support 90, relaxing the tension of spring 98, by permitting to yoke 94 to ride downwardly, thus progressively permitting casing 18 to move progressively downwardly more readily until it is acting against only the draw-bar spring 102 and diaphragm assembly 104, the downward movement of the casing causing the centers of rotation of the vanes and rotor to approach each other, while at the same time causing the variation of the angles of the vanes to be more equalized, that is, since the casing and its vanes are being forced downwardly by pressure from the compressed gas their center 42 approaches the center 44 of the drive shaft 26 and rotor 32, the vanes thus not being forced to assume such varying angles, and the volume between vanes becoming progressively more equal, until, when the pressures (and volumes) between the vanes and the race have substantially equalized through equal angles between vanes and equal volumes in the upper and lower plenums, the compressor is no longer pumping or compressing, and although it maintains the pressure field set, it quits recycling and will remain thus until its system is upset by either movement of the thermostat bellows 92 responsive to an increased liquid temperature entering the receiver 88, or until a drop in pressure within the race resultant from a pressure loss in the gas entering the race from the cooling coils 210 upsets the out-pressure or compression ratio maintained by the vanes and valve 76, at which time the race again moves toward the up position. Obviously, the receiver is provided with an outlet 106 to the evaporator 210 to maintain the closed system.

Although FIGURE 1 illustrates high pressure valve 76 to be off-set from the longitudinal vertical axis of the receiver and compressor for purposes of clarity, it is critical as shown in FIGURE 2 to proper functioning of the automatic operation hBllClllfibOVC described that both valve 76 and automatic control means 92 are at the diametric center of the vane race, rotor and housing. Cutoff valve 220 in the refrigerant line between the pump high pressure valve 76 and condenser 200 will, when closed, cause a pressure build-up in the pump, reducing pump eccentricity to near zero so pump action will cease. Cut-off valve 220 may be actuated either manually or electrically. When open, the system will continue to respond to temperature changes in control means 82 or pressure drop in the refrigerant from the evaporator. It is noted that diaphragm chamber 100 is holding the pressure through means of one-way or check valve 104. The slight pressure drop experienced as each vane passes the outlet port 76 imparts a tendency to casing 18 to rise. This tendency is overcome by diaphragm 106 which, holding the pressure, stabilizes the casing, damping out pulsations.

Thus, there has been provided a rotary vane device which has vanes varying the compression ratio in accordance with the position of the race in relation to the rotor, this positioning controlled by thermostat 92, spring 98 is responsive to the temperature of the liquid from condenser 200 entering receiver 88, i.e., the pump system is independent of internal or auxiliary systems. The compression ratio is at a maximum when the rotor and race are offset their maximum distance and the system liquid is at its highest temperature and equalizes as the offset distance is minimized responsive to system temperature and pressure, the vanes varying from a maximum angle between any two vanes adjacent in the upper quadrant of the race when the race is offset from the center of the rotor a maximum distance, to a substantially 90 angle between any two adjacent vanes when the race has moved downwardly responsive to the attainment of preset equalizing pressures and is substantially coincident with the rotor. Thus, the invented device is of high efficiency and automatic.

In summary, there has been provided a system which does not require any clutch means, permits maximum efliciency by relying wholly on system pressure to control it, is independent of prime mover speed since it can pump only at pressures which are directly responsive to the temperature of the liquid refrigerant in the system and therefore requires no recycling valve, and is directly driven by the prime mover or a belt. This is accomplished, through the progressive geometric movement of the vanes, which is dependent on positioning of the casing bore in relation to the rotor and responsive wholly to internal refrigerant system temperature and pressure.

Having thus described my invention, I claim:

1. A progressive geometric movement rotary vane compressor system comprising:

(A) a housing having a port therein for receiving gaseous refrigerant from an evaporator,

(B) a casing forming a pressure chamber, the interior thereof constituting a vane race mounted eccentrically for vertical movement in said housing, said casing having gaseous refrigerant inlet means forming a communication port to the interior low-pressure side of said pressure chamber from said housing port, and gaseous refrigerant high-pressure outlet means porting the high-pressure side of said vane race to the system,

(C) a rotor eccentrically positioned within said casing and concentrically positioned within said housing having vanes extending from the true center of said casing so that the angular relationship of said vanes varies with respect to each other and to said rotor from a maximum when said casing center is offset a maximum distance from said rotor to a minimum when said casing center coincides with the center of rotation of said rotor,

(D) means responsive to system demand varying the center of said casing from the eccentric position relative to said rotor to a position wherein said casing center, said rotor center of rotation and the center of rotation of said vanes are coincident, said means comprising:

(1) a receiver positioned on said housing for receiving the liquid system refrigerant from a condenser, said receiver commpuicating with the system evaporator,

(2) means responsive to temperature fixedly supported within said receiver, said means expandable upwardly on the introduction of a relatively warm refrigerant and collapsable on the introduction of a relatively cool refrigerant.

(3) a draw bar passing from said receiver through said housing and fixedly attached to said casing and movable vertically therewith, said draw bar responsive to the expansion of said temperature responsive means to cause said casing to move toward the eccentric position against the compressor pressure to affect increased pressure output,

(4) means normally biasing said casing toward the eccentric position and operative to balance the pressure-biasing forces to achieve a pre-set output, and

(5) said receiver having an outlet communicating directly with the system condenser, said outlet comprising in part, casing damping means operative to damp out casing movement due to pressure drop when said vanes pass haid highpressure outlet means.

2. The compressor system defined in claim 1, wherein:

(A) said finely supported temperature responsive means comprises:

( l) a bracket attached to said housing,

(2) a bellows thermostat mounted on said bracket for upward expansion responsive to the introduction of a relatively warm liquid refrigerant into said receiver,

(3) a yoke having a base positioned over said damping means and a condenser operative. to cause thermostat for upward movement therewith rea presure buildup acting upon said casing to subsponsive to said thermostat, stantially off-set the casing tendency to upward (4) a tension spring mounted at its lower end on movement through said tensioning means whereby said yoke base and contained on the upper end said casing maintains its concentric position and by one end of said draw bar and compressible pressure field. by upward movement of said yoke responsive 5. The compressor system defined by cailm 3 wherein: to expansion of said thermostat, said system includes a cut-off between said diaphragm (B) said means normally biasing said casing toward chamber and the condenser operative, on being cut the eccentric position comprises a tension spring 10 off, to cause a pressure buildup within said diapositioned around said draw bar and contained on phragm chamber to overcome said casing biasing one end by said draw bar and on the other by said housing, said spring passing through the base of said yoke so that said yoke is moveable independently of means whereby said casing maintains its concentric position and ceases compression while maintaining the rotation of the rotor.

said spring. 15 3. The compressor system defined by claim 1 wherein: said casing damping means comprises: a diaphragm chamber in communication with the high-pressure References Cited UNITED STATES PATENTS outlet means of said casing, said diaphragm cham- 8/1905 Smith 91 124 ber receiving one end of a gas-porting tube having 20 800923 9/1905 Sharpneck' therein a check valve operative to permit the com- 2470655 5/1949 Shaw 23O 207 pressed gaseous refrigerant from said casing to flow 2716946 9/1955 t only one way, said tube moveable vertically with 21804017 8/1957 Wlrz' said casing, a diaphragm within said chamber and 2942774 6/1960 Blackman 230 138 attached to said gas-porting tube wherein the highpressure within said chamber is operative to dampout pulsations caused by the tendency of said casing to move on the loss of pressure resultant from each stroke, said chamber being in direct communication with the refrigerant system. 30 4. The compressor system defined by claim 1 wherein: said system includes a cut-off between said casing 25 DONLEY J. STOCKING, Primary Examiner W. J. GOODLIN, Assistant Examiner US. Cl. X.R. 417-292

Images