US2275774A - Compression or vacuum machine - Google Patents

Description

Patented Mar. 10, 1942 Seat Ch 1 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to improvements in compression or vacuum machines, and has for a main object the provision of means for introducing lubricant to the bearings and moving parts of such machines, said means being controlled entirely by the movement of displacement elements in said machines.

This application is a continuation in part of application Serial Number 105,426, filed October 13, 1936, now issued as Patent No. 2,144,681 of January 24, 1939.

Another object of the invention is the provision in a compression or vacuum machine employing a rotary piston having recesses formed therein in which displacement elements may move, of means for supplying lubricant successively to recesses in one portion of the machine for lubricating said elements, said lubricants also serving to cushion said elements as they pass through other portions of the structure.

Still another object of the invention is the provision in compression or vacuum machines employing rotary pistons and reciprocating displacement elements, of ducts communicating with recesses in which said displacement elements move whereby a. void or partial vacuum is created in said recesses behind said elements, there by permitting oil to flow through said ducts and into said recesses, and the provisionof other ducts communicating with said recesses in other portions of said machines whereby said oil serves both as a cushion for said elements and as a lubricant for said elements and the bearing of said machine via said closed ducts.

A further object of the invention is the .provision in a rotary compressor of reciprocating displacement elements, outer portions of which are adapted to move air or gas and the inner portions are adapted to move a liquid.

Still another object of the invention is the provision in compression or vacuum machines of reciprocating displacement elements moving within recesses formed in the rotary pistdn of said devices and having formed therein passages, the discharge cross sections of which vary-- with the depths of the displacement elements in their associated recesses.

Other objects and advantages of the invention will be apparent to those skilled in the art.

Referring to the drawings:

Figure 1 is an elevation, partly in section, showing details of construction which effect one embodiment of the new and improved method of lubricating the working parts and cushioning the moving blades or displacement elements;

Figure 2 is a sectional elevation of the pump shown in Figure 1;

Figure 3 is a sectional view of the pump shown in Figure 2 taken along the line 3-3 thereof;

Figure 4 is an inner face view of one of the end plates of the pump shown in Figure 1;

Figure 5 is a sectional elevation of a. roller type of rotary pump employing substantially the same method of oiling and cushioning;

Figure 6 is a face view of an end plate of the pump shown in Figure 5;

Figure '7 is a side view of a new and improved blade or displacement element;

Figure 8 is a sectional view of the blade taken along the line 8-8 of Figure 7;

Figure 9 is a bottom view of the blade shown in Figure 7;

Figure 10 is a sectional elevation showing a further modification of the invention;

Figure 11 is a fragmentary view of a portion of a compressor employing the improved blades or displacement elements shown in Figures 7-9;

Figure 12 is a view similar to Figure 11, showing a further arrangement of the blades or dis placement elements shown in Figures 7-9 in connection with a vacuum pump;

Figure 13 is an elevation, in section of the pump employing new types of blades and in which the duct communicating with the recesses behind the blades on the compression side of the pump are omitted;

Figure 14 is a sectional view of a portion of a rotary pump showing one method employed in Figure 10 of leading the oil to the duct communicating with the recesses behind the blades on the suction side of the pump; and

Figure 15 is a view similar to Figure 11 showing a further modification.

Referring first to Figure 5 which is a sectional elevation of a rotary pump or compressor employing rollers as displacement elements, a tapped hole 33 is provided to receive a. suitable oil fitting (not shown) to which a pipe may be connected leading to a source of lubricant. A duct 34 is formed in the pump body 35 by drilling a hole therein and closing the lower end of the hole by means of an oil-tight plug. The upper end of the duct 34 communicates with a transverse hole 3'! which in turn communicates on each end thereof with straight grooves 38 formed in the end plates one of which is designated by the numeral 40 and shown in Figure 6. A curved groove 39 in the end plate 40 communicates with the straight groove 33 and is so positioned that it also communicates with the slots Ha, llb, llc,

4Id and Me, behind the blades 42a, 42b, 42c, 42d and 42e while said blades are making suction strokes in the pump. As the rotor rotates, the slpts 4If, 4Ig and Mn also pass through the suction zone and at that time communicate with the curved groove 39.

A second transverse hole 45 in the pump body 35 communicates with slots 43 in the end plates and also with holes in the end plates, one of which is designated by the numeral 46, which communicate with the bearings of the pump. One of the bearings is designated by the numeral 41 in Figure 6.

The same method of leading oil to the bearings will be more clearly shown in connection with the description of the vane type pump illustrated in Figures 1-4 inclusive. The end plate shown in Figure 4 is similar to that shown in Figure 6 except that the spacing of the ducts is slightly different to conform to the type of pump with which it is used.

The spaces behind the blades or vanes 42f, 42g and 42h become filled with oil while the blades associated therewith are moving out on their suction strokes. Therefore, during the compression stroke (and the blades named are illustrated as on the compression stroke) the oil which entered the spaces behind the blades not only lubricates them but also acts as a cushion behind the blades and the action of the blades in moving toward the bottoms of the slots forces the oil out into the bearings via the curved grooves 44, the straight slots 43 and the transverse holes 46. While the pump is operating air or gas enters the inlet end 21 and is discharged from the discharge end 48.

In the vane" type of pump shown in Figures 1, 2, 3 and 4, the body I41 is provided with a cylindrical bore I48 having flanged ends I49 and I50, to which end plates II and I52 are respectively secured. The end plate I52 is provided with a bushing I53 which forms a bearing for one end of the shaft I54. Likewise, the end plate I5I is provided with a bushing I55 which forms a second bearing for the shaft I54. The end plate I5I is also provided with a stumng box comprised of packing material I56, a gland I51, and a tightening nut I58. The body I41 is provided with an inlet port I59 and a discharge port I60. The shaft I54 carries a rotor I6I, which has formed therein a plurality of slots, one of which is indicated by the numeral I62. Each of these slots is provided with a blade or vane I63. Due to the fact that the shaft I54 is positioned eccentric to the bore I48, the vanes I63 reciprocate in the slots I62 as the shaft and rotor are revolved.

As the action of the rotary pumps of the vane type is well known in the art, it will not herein be described in detail except in connection with the description of my new features.

An oil pipe 200 may be secured to the tapped hole I64 by means of a suitable fitting I99. A duct I65 formed in the end plate I 5I communicates with a cross hole I66 formed in the body I41, and also with a duct I61a which in turn communicates with the space I19 between the bushing I55 and the packing I56. The duct I65 also communicates with a groove I61 in the end plate I 5I The cross hole I66 communicates with a groove I69 in the end plate I52, and in turn this slot communicates with a. curved groove I10, which is similar to and parallel with the curved slot I68 in the end plate I5I.

The pair of curved grooves I68 and I10 span an angle of approximately 180. In other words, they extend from a line cutting the sealing point of blade I1I to a line cutting the blade I63 at the point of its greatest outer movement in the slot I62. This permits a maximum amount of lubricant to be drawn into the slots and grooves and the spaces in the slots I62 behind the blades. In cases where it is desirable that a less amount of lubricant be supplied to the moving parts of the pump, the polar angle of the curved grooves I66 and I10 may be decreased according to the amount of lubricant desired. It will be noted that the radius of the curved grooves I68 and I10 is such that the grooves are in line with the bottoms of the slots I62 in the rotor I6I.

The end plate I5I is also provided with a second curved groove I12 (Figure 3) having substantially the same radius as the grooves I68 and I10. Likewise, the end plate I52 is provided with a curved groove I13. The groove I12 terminates in a straight slot I14, and the groove I13 terminates in a straight slot I15. A cross hole I16 formed in the body I41 communicates with the straight slots I14 and I15.

A duct I11 formed in the end plate I5I commum'cates with a second duct I18 which serves to lead oil to the bushing I55. Some of the oil fed to the bushing I55 enters the cavity I19 and lubricates the packing I56 and the gland I51 of the stufling box. The end plate I52 has a cross hole I having one end communicating with the slot I15, and the other end communicating with the duct I8I which serves to lead lubricant to the bushing I53. As the blades or vanes I63 are forced downwardly in the slots I62 of the compression stroke, the cushion of oil in the slots I62 is forced into the grooves I12 and I13, from whence it passes via the slots I14 and I15 to the ducts I18 and I8I, thence to the bushing I55 and I53, respectively, thereby furnishing an infallible source of oil under pressure for lubricating the bearings and the stuffing box. The lubricant is supplied from a suitable body or supply of lubricant, passes via the pipe 200 and thence via the passages I65 and I66, and via the grooves I61 and I69 the curved grooves I68 and I10 to the bottoms of the rotor slots of those blades which are then passing through the suction zone of the pump, due to the suction created behind said blades. The passage I61a (Figure 1) communicates with the outer end of the bearing I55 and with the suction zone of the pump via the curved groove I68. Likewise the passage "01) communicates with the outer end of the bearing I53 and with the curved groove I10 and the pumps of the rotor slots of those blades which are then passing through the suction zone of the pump. The action of the blades in this suction zone removes excess oil after the same is passed through the bearings I55 and I53.

The new and improved blade illustrated "n Figures 7, 8 and 9 and designated by numeral 20I may be generally rectangular in form and has formed therein a plurality of grooves, one of which is designated by the numeral 202. The grooves 202 are of maximum depth at the bottom 203 of the blade and taper toward the top 204 of the blade, terminating at a point 205 near the upper surface or top 204 of the blade.

In other modifications the blade may be provided with the usual packing strip in which event the top 204 would be curved to fit the packing strip. As packing strips are old and well known in the art, it is not deemed necessary to show a modified form of the blade with the packing strip.

Referring now to the Figure 11, a portion of the pump body 206 is shown carrying a rotor 20'! on shaft 208. This pump carries the new and improved blades, those shown being designated as 201a, 20|b and 20lc.

The oil groov I68a similar to the oil groove I68 shown in Figure 4, is in communication with the area 209 at the bottom of the blade 201a and the area 2) underneath the blade 20lb. In the position shown, these areas have become filled with oil via the oil groove 58.10. The rotor 20'! rotates counter-clockwise in the direction of the arrow and as the blades move out of the suction zone, they are descending in their slots, that is to say, moving toward the bottoms of the slots, thereby reducing the areas and tending to compress the oil underneath the blade in said areas. Due to the presence of the grooves 202 some of the oil squirts out via the grooves and lubricates the surface of the cylin der bore 2l2. The blade 20lc has moved in a counter-clockwise direction to a point where the area 2 between the bottom of the slot and the blade 20lc is in communication with the groove [10a which corresponds to the groove H in the pump shown in Figure 2. Since the blade 20lc is continuing to descend in its slot, some oil has squirted out via the grooves 202 and the remainder of the oil is passed on to lubricate the bearings as described above in connection with Figures 1 and 2 via the groove 110a.

The oil which is deposited on the surface of the cylinder bore 2l2 forms a lubricant for the same blade which caused the oil to be there. For example, the oil which passed to the cylinder walls via grooves in the blade 20l b forms a lubricant for said blade.

In the modification shown in Figure 12 in which the grooves 202 face in opposite direction from those shown in Figure 11, the oil deposited on the cylinder bore by one blade lubricates the following blade. For example, the oil deposited on the cylinder bore by the blade 20Ib' lubricates the blade 20la'.

In the modification shown in Figure 10, the pump body generally designated by the numeral 2|5 has an inlet port 2|6 accessible via the inlet opening 2ll. An oil sump H8 is formed within the body communicating with the discharge port of the pump and a vertical passage 2I9 terminates with an outlet opening 220. A bafile plate 22| is provided adjacent to the discharge port 222 of the pump so that the compressed fluid medium, together with the oil contained therein impinging against the same will separate the heavier particles of oil from the compressed material. A bafile 223 extends downwardly from the casing M and a passage 224 is formed between the bafile 2H and the baffle 223.

The sump 2|8 contains a body of oil 225 and as the oil is used up, fresh oil may be replaced via the hole 226. A plug 221 is provided for closing the hole 226 and an extension 228 of the plug 221 is provided for determining the oil level.

The rear end plate 229 is provided with an annular groove 230 communicating with those slots of the rotor 23| which are in the suction zone, for example, the slots 232a, 232b, and 2320. The arcuate slot 230 as may be seen in Figure 14 has communicating therewith a passage 233. The passage 233 in turn communicates with a passage 234 which extends through the pump body parallel to the axis of the shaft 235. A fitting 236 communicates with the passage 234 and has secured thereto a pipe 231 which extends through a wall 238 to communicate with oil 225 in the sump 2l8.

When the pump is operating the partial vacuum created behind the blades 240 while said blades are in the suction zone of the pump is communicated to the slot 230 and thence via the passages 233 and 234 and the pipe 237 to the body of oil 225, thereby causing oil to enter the spaces behind the blades (232a, 232b, 2320 as illustrated in Figure 10). The disposal of this oil will presently be described in connection with a similar groove communicating with the bottoms of the rotor slots in a compression zone in the pump. An arcuate groove 24l formed in the end plate 229 communicates with the bottoms of said last-mentioned slots and receives oil from said slots as the blades therein are moved toward the bottoms of said slots in said compression zone. Communicating with the arcuate groove 24l is a series of passages such as those shown in Figure 3 leading to the bearings of the pump, and a passage 242 which terminates in an outlet 243 whereby excess oil may be returned to the body of oil 225 in the sump.

The drive end plate of the pump shown in Fig ure 10 is not shown, the same being similar to the drive end plate I5I shown in Figures 1 and 3. An arcuate groove similar to the groove 230 in the end plate 229 is provided in the drive end plate and means is provided to connect this arcuate groove with the passage 234. The oil which passes into the slots behind the blades while on the suction stroke as above described, acts as cushions for the blades as they pass from the suction zone to the compression zone and the blades descending in the slots against said oil cause some of the oil to discharge via the grooves 202, to the cylinder wall. The remainder of the oil passes via the arcuate groove and the passages associated therewith to the bearings, and the excess oil passes via the passage 242 and the outlet 243 to the main body of oil 225. Thus is provided a pump for air or gaseous mediums in which the outer portions of the blades act upon said mediums, and a second pump within the first pump provided for pumping liquid (oil) and positively directing said liquid to definite points within the structure.

The modification shown in Figure 13 is similar to that shown in Figure 11, with the exception that the arcuate groove or slot |a communicating with the bottoms of the rotor slots M0 is omitted. In this arrangement, the oil at the bottom of the slots in the compression zone, for example 21m, 2!": and 2llc acts as a cushion behind the blades and as the blades descend toward the bottoms of the slots, the oil is discharged via the grooves or slots 202a to the walls of the cylinder. Some oil is also discharged into the clearance spaces between the ends of the blades and the end plates and thereby some oil would reach the bearings. The used oil would pass out through the discharge I60a.

In the last arrangement described, the outer portions of the blades serve to pump air or gaseous medium and the inner ends of the blades serve as a liquid pump, thereby providing two pumps within a single body, both pumps discharging through one and the same outlet.

In the modification shown in Figure 15, a shaft 300 carries a rotor 301 in which the slots, one of which is designated by the numeral 302 are formed therein at obtuse angles instead of radial (as shown in the other modifications) and while these slots are formed at such an angleJs to support the blades 303 tangential they may be formed at other angles than those shown. The pump may be provided with an annular (suction zone) groove 304, and an annular (compression zone) groove 305 in the end plates, one of which is designated by the numeral 306.

Where the blades 303 are provided with grooves 301, some of the oil passes via said grooves to the wall 309 of the cylinder 308.

In some instances the annular groove 305 may be omitted in which case the pump functions in the manner described for Figure 13.

It is obvious that the herein described combi-- nation of suction and pressure for lubricating pumps may be modified and many changes may be made in the embodiments herein shown and described without departing from the spirit of the invention, as defined in the following claims.

What is claimed is:

1. In a rotary air pump in combination, a pump body having a cylindrical bore and inlet and outlet ports formed therein, inlet and outlet passages formed in said body. a cavity formed in said body to one side of said .bore, said cavity being in open communication with said outlet passage and having its lower portion forming an oil sump, an upper portion of said cavity forming a pocket adjacent to the discharge end of said outlet port, a curved baflle in said cavity having its upper end terminating in and sumciently spaced apart from the upper end of said pocket to prevent the discharged air from being restricted, the lower end of said baffie terminating in spaced relation to the surface of a normal level of oil in said sump, a slotted rotor in said bore carrying blades reciprocating in said slots and moving in suction and compression zones in said pump, said blades moving away from the bottoms of said slots when in said suction zone and moving towards the bottom of said slots when in said compression zone, means including ducts communicating with the bottoms of all of those of said slots in the suction zone and connected to receive oil from said sump, whereby said oil is supplied to the slots behind the blades in said suction zone, means including ducts connected to the bottoms of all of those of said slots in said compression zone for lubricating at least some of the moving parts of said pump due to the compressing action of the blades descending toward the bottoms of said slots during the entire time said blades are moving in said compression zone, and means whereby said oil after lubricating the parts as aforesaid passes with the compressed air via said discharge port to said pocket, said air being unrestrictedly divided into two streams by said curved baflle, permitting the oil to impinge gently upon both sides of said baflle to facilitate the separation of the oil from said air.

2. A rotary air pump according to claim 1 in which a second curved baflle, spaced apart from and substantially parallel to said first curved bafile, forms an extension of said outlet passage and has its lower end terminating in said cavity a greater distance from the surface of oil in said sump than the distance of the lower end of said first bafile from said oil.

FREDERICK KRAISSL, JR.

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