US2824687A - Rotary compressor - Google Patents

Description

Feb. 25, 195s 'Filed oct. 26, 1955 H. C. OSTERKAMP ROTARY COMPRESSOR 2 Sheets-Sheet 1 Feb. 25, 1958 f H. c. osTERKAMP 2,824,687

ROTARY COMPRESSOR Filed oct. 26, 1955 Y 2 sheets-sheet 2 ATTORNEYS v Y.

United States lPatent "f- ROTARY COMPRESSOR Henry C. Osterkamp, Elm Grove, Wis., assignor to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application October 26, V1955, Serial No. 542,832

4 Claims. (Cl. 230-158) The present invention relates generally to improvements in the art of compressing air or the like, and relates more particularly to improvements in the construction and operation of multi-stage rotary air compressors of the sliding vane type.

A primary object of my present invention is to provide an improved multi-stage rotary compressor wherein the low and high pressure rotors are disposed in axial alinement with the low and high pressure chambers being formed by a simple partition plate disposed and sealingly retained within the bore of a common main cylinder.

Another specic object of my present invention is to provide an improved multi-stage rotary compressor of the sliding vane type in which a single unitary cylinder houses both the low and the high pressure rotors which operate in separate chambers segregated and sealed from each other by a readily removable partition.

Still another specific object of the present invention is to provide an improved multi-stage rotary compressor wherein all of the parts are readily accessible merely upon removal of the end head of the cylinder and axial withdrawal of the low and high pressure rotor assembly.

A further specific object of the present invention is to provide an improved rotary compressor assemblage which comprises essentially a single unitary cylinder having a common bore of uniform diameter closed on opposite ends by removable end heads,.a single unitary shaft extending eccentrically through the bore and journalled for rotation in the end heads, low and high pressure rotors mounted on the shaft for rotation therewith and each having radially extending sliding vanes cooperable with the wall of the bore, a partition plate disposed between the rotors and peripherally sealed within the cylinder bore to form low and high pressure chambers, means forming an air communication passageway between the low and the high pressure chambers, and a lubricant pump housed entirely within one of the end heads and driven by the unitary rotor shaft.

These and other specific objects and advantages of the invention will become apparent from the following detailed description.

A clear conception of the features constituting the present improvements, and of the mode of constructing and operating a typical rotary compressor embodying the invention, may be had by referring to the drawings accompanying and forming a part of this specication wherein like reference characters designate the same or similar parts in the various views.

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Fig. 1 is a longitudinal section through a typical multi-vK stage rotary sliding vane type compressor embodying the invention, the section having been taken along the irregular line 1-1 of Fig. 2;

Fig. 2 is a transverse section through the compressor taken along the irregular line 2 2 of Fig. l; and

Fig. 3 is a somewhat enlarged fragmentary longitudinal section through a portion of the unit taken along the irregular line 3 3 of Fig. 2.

While the several features of the present invention have been shown and described herein as being embodied in a compressor of the rotary sliding vane type having two compression stages and being especially applicable for direct connection withan engine flywheel, it is not intended to unnecessarily limit or restrict the invention and its application or' use by reason of such limited ern-y bodirnents, since the same features could of course bez utilized to advantage in rotary compressors of more than two stages and adapted to be coupled in any suitable man'- ner with a suitable driving source.- It is also contemplated that certain specific descriptive terms utilized here-` in shall be given the broadest possible interpretation consistent with the disclosure.

Referring to the drawings, the improved assemblage disclosed therein as illustrating the embodiments of the invention comprises, in general, a single' unitary cylinder S having a single bore 6 of uniform diameter extending longitudinally therethrough, a pair of end heads 7, 8 removably secured to the opposite ends of the cylinder 5 as by means of bolts 9, iii respectively to thereby clos'eV the opposite ends of the bore 6, the end head 8 preferably' being provided with an outwardly open recess 11 therein for purposes hereinafter more fully set forth, a single unitary shaft l2 extending eccentrically through the bore 6 and journalled for rotation in the end heads 7, 8, the shaft 12 having one end extending iritoV the recess l and having the other end thereof suitably' coupled as by means of splining 13 to a driving source such as the flywheel 14 carried by the crank shaft l5 of anvengine or motor, low and high pressure rotors 16, 17 respectively carried by the shaft l2 for rotation therewith, each of the rotors 16, 17 having the usual series of radially extending sliding varies or blades i8, 19 respectively cooperable with the wall of the bore 6, a partition wall or plate 22 disposed loosely on the shaft 12 between the rotors 16, 117 and peripherally coacting with the wall of the bore` 6 to thereby'fcrm low and high pressure chambers 20, 21'respectively therein, the partition 22 preferably being se# cured in position within thebore das by means of a series of machine screws 29 or the like, means forming an air communication passageway 23, 24 between the low and high pressure chambers, the air communication passageway 23, 24 preferably being formed directly in the cylin' der 5 and extending outwardly around the bore 6 therein, means such as a pair of cooperating rotors 25, 26 housed within the recess lli of the end heads 8V and providing alubricant pump, the rotor 25 of the pump'being mounted on and driven by the endl of the shaft 12, and a cover 27 for the recess 1l removably secured to the end head 8 as by means of bolts 28 to protectively confine the pump within the recess 11.

The end head 7 may be conveniently formed in the rotor 16 may, if desired, be formed integral with the shaft 12 as by casting the same of one piece, or it may be rigidly secured to the shaft 12 in any suitable manner as by means of a key or the like, the high pressure rotor also being secured to the shaft 12 for rotation therewith in any suitable manner as by a key 34. The partition 22 should loosely surround the shaft 12 so as to permit free rotation of the shaft relative ,to the partition, and the periphery of the partition 22 should preferably be sealed about the wall of the bore 6 as by means of suitable O-ring seals 35 retained in suitable annular grooves 36 in the wall of the bore 6.

Suitable bearings 37, 38 may furthermore be provided in the end heads 7, 8 respectively for facilitating rotation of the shaft 12, and gaskets may, of course, be provided wherever necessary to minimize leakage and loss of air. The cylinder may be cast or otherwise formed in one piece with integral walls 39, 40, 41, 42 being provided in the casting for forming the air passageways, one side of the cylinder being preferably closed as by a suitable cover plate 43 having an inlet opening 44 for supplying air to the low pressure chamber through suitable ports 45 and another side of the cylinder 5 being closed as by a suitable removable cover plate 46 having a discharge or outlet opening 47 therein for discharging air from the high pressure chamber 21 through suitable ports 48. Accordingly, the walls 39, 40 cooperate with the cover plate 43 to form the low pressure air inlet chamber 49, the walls 39, 42 cooperate with the cover plate 46 to form the low pressure discharge chamber and passageway 23 which receives the initially compressed air from the low pressure chamber 20 through suitable ports 50 and conducts the initially compressed air around a side of the cylinder beyond the bore 6 to the high pressure inlet chamber 24 formed by the walls 40, 41, the initially compressed air being then conducted through suitable intake ports 51 to the high pressure chamber 21 and then through the ports 48 to the outlet 47.

The pump formed by the rotors 25, 26 working in the recess 11 formed in the end head 8 may be of the usual gear type, with the rotor being secured to the end of the shaft 12 as by means of a key 53 and the rotor 26 may be freely rotatable on a stub shaft 54 or the like. The inlet of the lubricant pump formed by the rotors 25, 26 may communicate in the usual manner with a source of lubricant supply and the lubricant discharged by the pump may be conducted in a usual manner through suitable conduits or passageways 55, 56, 57 formed in the end head 8, a wall of the cylinder 5, and the end head 7 respectively. From the conduit 56 lubricant is supplied through a branch or branches 58 to the high pressure chamber 21, while lubricant is also supplied to the low pressure chamber 20 from the conduit 56 by means of one or more branches 59, the conduit 57 in turn supplying lubricant to the bearing 37 with the lubricant escaping from around the bearing 37 to the recess 31 in the end head 7 and being drawn back to the low pressure chamber 20 as by means of a conduit 60. The lubrication system as such is, however, old in the art and does not form a part of this invention except for the pump construction and the manner in which itis recessed and housed separately within the end head 8.

In operation, the shaft 12 is rotated in the direction of the arrow in Fig. 2 by means of the engine through the iiywheel 14. The shaft 12 carries with it the low and high pressure rotors 16, 17, and air to be compressed is drawn in through the inlet 44 into the chamber 49 and then through the ducts 45 into the low pressure chamber `20 as also indicated by the arrows. The vanes 18 act to compress the air entering the chamber 20 as the low pressure rotor revolves, and the initially compressed air is forced through the ducts 50 into the chamber 23 and then through a passageway formed in the cylinder outside of the bore 6 in the direction of the arrows to the chamber 24. From the chamber 24 the initially compressed air `is drawn through the ducts or ports 51 into the high pressure chamber 21 and is further compressed by the revolving blades 19 carried by the rotor 17, the finally compressed air being discharged through the ports 48 and outlet 47, and to add flexibility to the unit, an alternate outlet 61 may be provided in another wall of the cylinder as shown in Fig. 2. As the air is thus compressed, the lubricant pump also forces oil or other lubricant in the direction of the arrows in Fig. 3 through the several conduits to aord lubrication of the compressor.

From the foregoing detailed description, it is believed apparent that the present invention contemplates the provision of a multistage rotary compressor of the sliding vane type possessing extreme simplicity and which may be readily constructed at exceedingly low cost. The improved unit is composed of relatively few parts, all of which are readily accessible for inspection, replacement and/or repair. Access to the high pressure rotor 17 and its vanes 19, may, of course, be readily attained by merely removing the end head 8 in an obvious manner without in any way disturbing the lubricant pump confined within the recess 11, and by removing the machine screws 29, the shaft 12, rotors 16, 17 and partition 22 may be axially removed as a unit, if desired, for access to all of the parts excluding the lubricant pump. On the other hand, access may be attained separately only to the lubricant pump, if desired, by removal of the cover plate 27 in an obvious manner, and access to the various air passageways and ports may be attained through removal of either or both of the cover plates 43, 46, both of which may likewise be secured to the cylinder as by means of bolts 62, 63. All parts of the assemblage may be manufactured and machined in an expedient manner, and these parts may obviously be quickly and easily assembled. While the partition 22 has been shown for purposes of illustration as loosely surrounding the shaft 12, it may be desirable to provide a bearing embracing the shaft within the bore of the partition, in which case a suitable branch lubricant line may be run to the bearing from the line 56. Also, the seals 35 might be entirely eliminated or any suitable number may be provided, and it may or may not be necessary or desirable to secure the partition in position by means of the screws 29. The bearings 37 may likewise be of any suitable type such as ball or roller bearings, and it is believed apparent that the conduit or branch lubricant line should lead into the chamber 20 on the suction side of the rotor. Furthermore, although the lubricant pump has been shown and described as being housed within the recess 11 of the end head 8, it may advantageously be housed within a recess provided for such purpose in the removable plate or cover 27.

.lt lshould be understood that it is not desired to limit this invention to the exact details of construction or to thepreclse mode of use herein shown and described, since various modifications within the scope of the appended claims may occur to persons skilled in the art to which this invention pertains.

I claim:

l. A rotary compressor comprising, a unitary generally cylindrical casing having a single bore of uniform diameter extending therethrough, end heads removably secured to each end of said casing to close the opposite ends of said bore, one of said end heads having an outwardly open recess therein, a single unitary shaft extending eccentrically through said bore and journalled for rotation in said end heads, low and high pressure rotors carried by said shaft for rotation therewith and each having radially extending sliding vanes cooperable with the wall of said bore, a partition disposed between said rotors and peripherally seated on the wall of said bore to form low and high pressure chambers therein, means forming an air communication passageway between said low and high pressure chambers, a lubricant pump housed entirely within said end head recess and driven directly by said shaft, and a flat removable cover plate for said recess to contine said pump therein.

2. A rotary compressor comprising, a unitary generally cylindrical casing having a single bore of uniform diameter extending therethrough, end heads removably secured to each end of said casing to close the opposite ends of said bore, one of said end heads having an outwardly open recess therein, a single unitary shaft journalled for rotation in said end heads and extending eccentrically through said bore and into said recess, a stub shaft extending from said one end head into said recess laterally of said eccentric shaft, low and high pressure rotors carried by said eccentric shaft for rotation therewith and each having radially extending sliding vanes cooperable with the wall of said bore, a partition disposed between said rotors and peripherally seated on the wall of said bore to form low and high pressure chambers therein, an air communication passageway between said low and high pressure chambers formed in said casing out wardly beyond said bore, a lubricant pump housed entirely Within said end head recess and comprising a pair of cooperating rotors, one of which is driven directly by said eccentric shaft and the other of which is carried by said stub shaft, and a at removable cover plate for said recess to confine said pump therein.

3. A rotary compressor comprising, a unitary casing having an integral cylindrical portion provided with a single bore of uniform diameter extending therethrough, end heads removably secured to each end of said casing to close the opposite ends of said bore, a single unitary shaft extending eccentrically through said bore and journalled for rotation in said end heads, low and high pressure rotors carried by said shaft for rotation therewith and each having radially extending sliding vanes cooperable with the Wall of said bore, a partition disposed between said rotors and peripherally sealed against the Wall of said bore to form low and high pressure chambers therein, an air communication passageway between said low and high pressure chambers formed directly in said casing outwardly beyond said bore, a cover removably secured to one side of said casing and having an air inlet communicating with said low pressure chamber, and another cover removably secured to another side of said casing and having an air outlet communicating with said high pressure chamber.

4. A rotary compressor comprising, a unitary casing having an integral cylindrical portion provided with a single bore of uniform diameter extending therethrough, end heads removably secured to each end of said casing to close the opposite ends of said bore, a single unitary shaft extending eccentrically through said bore and journalled for rotation in said end heads, low and high pressure rotors carried by said shaft for rotation there- With and each having radially extending sliding vanes cooperable with the wall of said bore, a partition disposed on said shaft between said rotors and peripherally sealed against the wall of said bore to form low and high pressure chambers therein, exteriorly accessible removable means for positively preventing displacement of said partition Within said bore while permitting axial withdrawal of said shaft, said low and high pressure rotors and said partition as a unit upon removal of said means and one of said end heads, and means forming an air communication passageway between said 10W and high pressure chambers.

References Cited in the tile of this patent UNITED STATES PATENTS 1,054,574 Leutz Feb. 25, 1913 2,215,256 Stoltz Sept. 17, 1940 FOREIGN PATENTS 149,323 Australia Dec. 5, 1952 660,528 France Feb. 19, 1929 1,025,278 France Jan. 21, 1953

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