US2644635A - Compressor - Google Patents

Description

L. K. WARRICK ET AL I July 7, 1953 COMPRESSOR Filed on 20. 1950 1 .fnr Jenl art I leZandKZUczrrzlc/ i and f nk Patented July 7, 1953 COMPRESSOR Leland K. Warrick, Muskegon Heights, and Frank E. La Flame, Spring Lake, Mich., assignors to Borg-Warner Corporation, Chicago, 111., a corporation of Illinois Application October 20, 1950, Serial No. 191,277

This invention relates in general to refrigerating apparatus and has reference to an improved form of compression constructions therefor.

Otherwise stated, the invention is embodied in refrigerator compressor constructions and is directed to simplify the structural features thereof and their mode of operation and to provide a refrigerant compressor which'may readily and'conveniently be employed universally to various types of refrigerator systems presently being commercially exploited.

More specifically stated, it is a particular object and accomplishment of the invention to provide a motor compressor assembly having sealed compartments providing convenient access and repair of parts thereof Without disturbance of the hermetic seal.

Moreover, the present device seeks to employ conventional parts Wherever necessary and possible, thereby to effect a further substantial reduction in the cost over the prevailing types of refrigerant compressors presently being employed.

It is a general object and accomplishment of the invention to provide a compressor construction which is particularly adaptable for employment in a refrigerating system of the type Wherein a refrigerating medium is circulated through a closed system and is successively compressed a gaseous state, condensed into a liquid and then expanded by evaporation at a relatively high pressure, the invention being particularly concerned with a compressor, the type generally applicable for employment for domestic or other uses where individual units of relatively small capacity are employed and have particular relation to an improved arrangement of parts having special application as a combination refrigerant motor and compressor unit.

It is a detailed object and accomplishment of the invention to provide amotor compressor unit for refrigeration purposes and employing an axial air gap motor as a power source.

It is another detailed object of the invention to provide a motor compressor unit of the above type and having an improved lubricating arrangement for insuring the delivery of the necessary lubricant to each of the vital moving parts.

Another object and accomplishment of the invention is to provide an improved refrigerating system by co-relating and especially designing the various elements of the motor compressor combination units to effect advantageous cooperation between said improved elements as will best serve the purpose of providing an eflicient 7 Claims. (01. 230-139) system capable of being manufactured at low cost and yet giving the maximum of satisfactory service in use.

A further object and accomplishment of the invention is to provide an improved unit designed for refrigeration purposes and which shall havea novel and compact arrangement of parts wherein said parts can be easily and readily assembled andserviced.

Another aspect of the invention is to provide a motor compressor combination unit having an improved arrangement of elements forming a sealed housing refrigerant compressor assembly having the minimum over-all co-axial dimen sion while maintaining a high efficiency of operation and effecting a reduction in the cost of manufacturing over'thatof similar units of present manufacture.

An ancillary object and accomplishment of the invention is to provide a new and improved motor compressor unit which is adapted to be economically manufactured and which is so designed as to permit the manufacture and assembly thereof in accordance with present day large scale mass production manufacturing methods of construction and assembly.

The invention seeks, as a further object and accomplishment, to provide a motor compressor unit particularly characterized by a design arrangement to more advantageously and satisfactorily perform the functions required of it and adapted to provide a compact unit which Will successfully combine the factors of structural simplicity and durability, and yet be economical to manufacture.

Additional objects, features and advantages of the invention disclosed herein will be apparent to persons skilled in the art after the operation and construction thereof are understood from'the within description.

' It is preferred to accomplish the various ob- I refrigerant motor compressor unit depicted in Fig. 2 and being taken substantially on the plane of the line it 3 in Fig. 2; and

Fig. l is a top plan View of a portion of the refrigerant motor compressor unit depicted in Fig. 2 and illustrating the construction of the seal partition wall disposed within the compressor proper and forming an important feature of the present invention, this View being taken substantially on the plane of the line 4-4 in Fig. 2.

The drawings are to be understood as being more or less of a schematic character for the purpose of illustrating and disclosing a typical or preferred form of the improvements contem" plated herein and in the drawings like reference characters identify the same parts in the several views.

As one possible example of advantageous em" ployment of the combination refrigerant compressor motor unit, reference is made to the drawings, particularly Fig. 1, wherein there is illus trated the refrigerant motor compressor unit with which the present invention is particularly concerned, and designated in its entirety by the numeral Iii as being adjunctively employed, for example, with a conventional refrigerating system designated in its entirety by the letter A.

The illustrated refrigerating system may ccm prise the motor compressor unit IE, herein shown as being of the hermetically sealed type and a directl connected condenser. After undergoing compression, the hot refrigerant flows through a discharge line l2 and through the convolutions of the condenser II which is air-cooled in the conventional manner, this extraction of heat be ing effective to reduce in some degree both. the pressure and thetemperature of the refrigerant, although both are quite high compared to normal atmospheric conditions.

After. the mixed vapors and liquid refrigerant are discharged from the condenser, they will flow through a conduit l3 into a valving device, which in this particular case is illustrated as a capillary tube or restrictor M, which is connected. to an evaporator 15 having a header I6. It is notable that the refrigerant is throttled in passing the restrictor I4 and thereafter will be expanded. at the discharge side of the restrictor and will be further expanded in the evaporator so that it will become quite cooled and is, therefore, capable of absorbing heat from the storage compartment from the refrigerator and from the contents thereof. After making its circuitous path through the evaporator, the expanded and expended re frigerant is then returned to the motor compressor unit Hi by means of a suction line ll, thus completing the closed circuit.

Suilice it to say, since the invention is not particularly concerned With the precise construction of the entire refrigerating system as illustrated, and/or its associated parts, they will not be further described in detail, and it is deemed sufficient for all intentions and purposes herein con tained to. show only portions thereof adjacent to and cooperating with the motor compressor unit contemplated herein.

I It is to be understood that details of construction of such refrigerating systems with which the refrigerant motor compressor unit contemplated herein may advantageously be employed, and/or their associated parts, may be modified to suit particular conditions or to satisfy the engineering genius of various manufacturers, and I do not wish to be limited tothe construction of these elements as set forth except where such co s u '4 tion particularly concerns the invention contemplated herein.

Heretofore, in prior art compressor constructions such units were usually disposed in a machinery compartment forming a part of the lower portion of a refrigerator cabinet. In such applications, the specific space requirements were not of paramount importance and the forward part of the cabinet adjacent the machiner compartment was provided with a hinged vegetable bin in an effort to utilize some of this space. In re cent years, the cubical content of a refrigerator has become a very important item and, therefore, it has become necessary to find Ways and means to effect reduction of the size of the mechanical elements of a refrigerator so as to provide, as much as possible, more usable space in the food compartment. It has been found that this can be accomplished in several ways. For example, the compressor may be reduced in size, thereby requiring a smaller machinery compartment, or, because of the reduction in size, the compressor and condenser forming a part of the mechanical structure of a refrigerator may be disposed on the back side of the refrigerator cabinet in the upper regions thereof adjacent the evaporator, thereby eliminating the necessity of a machinery compartment in the lower portion of the cabinet. This position of the compressor as described would permit utilization of the space formerly occupied by the mechanism as a part of the food storage compartment.

It is recognized that in the prior art numerous attempts have been made to provide a relatively small refrigerant compressor unit and yet main tain th desired capacity of the unit, but to the best of the applicants knowledge, only very few of the prior art structures have had limited suc=- cessful applications and have been accorded only limited commercial. recognition.

It is believed that this fact results from the deficiencies of the prior art structures, and their non-adaptability to effectively overcome the difficulties hereinbefore set forth.

Having thus described, by way of example, a possible adaptation of the sealed motor compressor unit and having described the general environment surrounding the adaptation, the specific construction and function of the parts of said sealed motor compressor unit will now be described in detail.

In the exemplary embodiment of the invention depicted in Fig. 2, the compressor 28 is shown as being enclosed within a casing 22 and as being in operative association with an electric motor generally indicated at 24 and which is illustrated as being constructed in part integrally with the casing 22 and arranged as a power source for operating the compressor. The construction of the motor 24 is a unique feature of the invention and preferably is of the alternating current type and adapted to be supplied with electrical energy through suitable conduits 25 operatively connected to the motor windings indicated generally at 26 and which are arranged internally of the casing 22. Electric current may be supplied to the motor for operating the same at intermittent periods and the supply of current to the motor may be under the control of a switch 2! which is operatively associated with the evaporator or freezer element l5 of the refrigerating system so that the compressor may be operated in such a way as to maintain the temperature thereof, and of the heated insulated compartment within which such evaporator may be arranged, within said predetermined temperature limits.

Attention is invited to Fig. 2, wherein it can be seen that the casing 22 is divided into two chambers 22a and 2%, the chamber 22a being hermetically sealed by virtue of the seal partition indicated in its entirety by the numeral 98 and has the compressor operativcly disposed therein, and the chamber 221) is provided with conventional seals and is adapted to have the stator portions of the motor operatively disposed therein.

In the construction illustrated in Figs. 2 and 3. the compressor 28 is arranged within the hermetically sealed chamber 22a. and the vaporous refrigerant from the evaporator is supplied to the intake side of the compressor through the suction port 28 via the suction line ll. The refrigerant is discharged from the compressor into the chamber 22a, of the casing 22 and the refrigerant is con-- ducted from the chamber 220,, through the discharge port 29 by means of the conduit 52, to the condenser E I. Portions of the chamber 22a func" tion as a lubricant reservoir and the lubricant therein preferably stands to a level indicated by the lines 30, or 3 l, in 2, depending on whether the compressor is mounted on a vertical. or horizontal plane, and the lubricant is subjected to the discharge pressure of the compressor. Because the refrigerant medium is supplied to the evaporator element [5 under control of a suitable refrigerant expansion control, such as a low side float or the like, the space defined by the chamber 22a and the condenser E I constitute the high pressure side of the refrigerating system.

The lubricant is provided for lubricating the working parts of the system such as the moving parts of the compressor 26 and parts of the motor 24 and some of the lubricant will circulate with the refrigerant throughout the system; however, a body of the lubricant will collect, as shown, in the lower portions of the chamber 220, which forms a part of the casing 22 to such an extent as to partially submerge the compressor 28 therein. Because the lubricant in the casing is subject to the discharge pressure of the compressor and as the compressor is partially submerged in the lubricant, the working parts of the compressor will be lubricated and sealed.

The casing 22 comprises a cup-shaped shell and a cover 4|. formed to define the shape as shown to take advantage of structural strength and save as much space as possible. 'The cover t! is provided with a flanged centrally disposed through aperture 62 provided with threaded formations adapted to receive for removable securement thereto a central stud-like support indicated in its entirety by the numeral 43, said stud-like support 63 being arranged to receive a suction line connection M and is provided with suitable channels such as for the passage of refrigerant. The stud-lilre member 43 is provided with a substantially cir=- cular-shaped radially projecting flange 43a provided with a finished surfacets which will form an end plate or closure for the rotary compressor, a circular shaped eccentric i? which can be seen in Figs. 2 and 3 as being disposed off center from the central axis of the compressor, and projecting axially from said eccentric 4? there is provided a bearing 48.

It is notable that the stator 36 and the motor windings are suitably secured to the cover 4| and it is important to understand that the cover H, the stator 36, the stud-like support member 43 in- It is notable that the cover M is 0 cluding the flange 43a, the eccentric 41 and the bearing 48 all remain stationary.

The compressor 20 further includes a cylinder 5d, a rotor 5!, a divider 54 and an end plate 55. Thus, it can be seen that the flange 43a which is provided with the finished surface 46, and the cylinder 50 including the end plate when assembled together, form a closed cylindrical chamber 52 or pumping space in which the rotor 51 is'arranged for rotative movement on the eccentric 41. The rotor 51 is freely journaled on the eccentric 4'5 and, it will be observed, is of less diameter than the pumping chamber 62 in which it is arranged.- The rotor 5! is of such 9 size, relative to the cylinder 50, that there is a small working clearance between the vertical faces of the rotor and the adjacent vertical faces defined by the finished surface 46 and the inside face of the end plate 55. Also, the diameter of the rotor 5! is such that there is a slight clearance between the periphery of the rotor 55 and the adjacent cylinder wall of the pumping chamber 62 at that point where the rotor 51 divides one side of the pumpin chamber 62 from the other side thereof, as illustrated in Fig. 3, and this clearance is maintained throughout the operation of the compressor as the cylinder 58 moves around an axis defined by the center of the compressor body in the direction of the arrow 63 in Fig. 3.

In Fig. 2 it can be observed that the bottom plate 55 is suitably secured to the cylinder 59 by means of the bolts as at 55 and the cylinder 5% is in turn fixedly secured to the rotor 35 of the motor 24. Thus, it can be seen that when the compressor is in operation, the cylinder will revolve in the direction indicated by the arrow 63 while the rotor 5| may freely rotate about the eccentric element 41 but the eccentric ele ment will remain stationary. This arrangement of parts defines important differential characteristics of construction heretofore not found in prior art practice.

The divider 54 is arranged for reciprocation within a slot 18 formed in the cylinder 50 and is disposed so that end portions thereof are in engagement with the periphery of the rotor, as illustrated in Fig. 3, so as to separate the suction gas from the discharge gas in the pumping chamber 52. The divider 54 defines fiat surfaces which slide on the flat surfaces of the slot in which the divider 54 reciprocates. The divider 54 preferably is of the same dimension with respect to thickness as the roto 5|, so that the divider 54 will form a movable seal between the periphery of the rotor 5i and the walls of the pumping chamber 62.

The pumping chamber is provided with an intake port as at l! and with a discharge port 72 preferably, but not necessarily, controlled by a valve as at 13, the divider 54 is reoiprocably disposed in the slot Hi and is guided in its movement by a spring '14, one end of which being received into a recess 16 disposed in the end portions of the divider 54 and the other end of the sprin being held in engagement with a wall defined by a refrigerant outlet chamber is forming a part of the cylinder 50, Spring [4 acts to hold the divider 54 in contact with the periphery of the rotor 5|.

The discharge port 12 is cut into portions of the cylinder 5!! and opens into the chamber '55 in which the valve 13, which controls the discharge port, is arranged. It can be seen in Fig. 2 that the chamber 75 opens into the chamber 22a of the casing 22. The valve 13 may be a flap valve or a check valve and is preferably anchored at one end thereof by means of screws as at "H.

In order to prevent a reversal of the pressures during certain operations of the compressor, there is provided a spring pressed valve 80 which is disposed in the suction line and it can be seen that when the compressor is in operation, the suction of the refrigerant coupled with the discharge pressure running through the entire circuit of the refrigerating system and entering the suction conduit 28 will force the valve 8!? to open and permit refrigerant to flow through the compressor. When the compressor is not in operation, discharge and suction pressures are not present and therefore the spring pressed valve 80 will be closed to prevent a reverse in the cycle of operation.

Thus, it can be seen that the path of the refrigerant through the compressor is defined by its passage through the suction conduit 28 and past the valve 80, through the conduit 45 and into the compression chamber 62, whereupon the rotary action of the cylinder 50 cooperating with the function of the divider 54 will compress the refrigerant and discharge the same through the discharge port 72, past the valve 13 and into the chamber 22a, whereupon it will be discharged from the chamber 22a by virtue of discharge connections 29 forming a part of the conduit 12.

It is notable that an important feature of the invention is the unique association of parts, particularly the departure from conventional compressors in that the cylinder 50, which in prior art constructions remains stationary, is rotated in this case which provides an assembled cornpressor unit of relatively small co-axial dimension giving the advantage of being able to mount the compressor unit on the back portions of the refrigerator cabinet if desired. In some adaptations it may be desirable to mount the compressor assembly in the conventional lower portions of the refrigerator cabinet. In this connection a minimum of space will be required and any savings in space may be transferred to enlargement of the food storage chambers, this being particularly true when the currently popular long door refrigerators are employed.

Particular attention is invited to Figs. 2 and i which clearly illustrate the specific construction of the partition wall 90 which is an important feature of the present invention. This wall effectively seals off the chamber 22d, thereby to provide a hermetically sealed compresso chamber in this region. The partition wall 9!] comprises a substantially circular plate-like element preferably formed of stainless steel or of another metal having similar characteristics. It can be seen in Fig. 2 that the peripheral edges of the partition wall 90 may be welded or frozen to adjacent portions of the casing 22 and the flange 43a as shown.

An important advantage of the aforementioned construction is that the cover 4| may be removed from its position on the central post 43, thereby to expose the motor windings and the stator 35 for convenient repairs thereon. Because the partition wall 90 provides the necessary seal to the chamber 22a, the motor windings can be repaired without disturbance to this seal arrangement.

Other important advantages of this construction are (1) that the complete refrigerating unit and the compressor dehydrating time period is much less than that now required because the motor windings and insulation do not have to be 8 dehydrated, (2) that the total possible residue in the refrigerating system is small because the motor stator (source of most 0f the metal chips, rust particles and cellulose fibres) is outside of the refrigerant system, and (3) that longer service life can be expected from refrigerating systems incorporating these compressors because the moisture and other minute deterioration compounds released from the stator insulation during infrequent operating temperature peaks cannot enter the refrigerating system causing progressive breakdown of the lubricating oils and motor stator insulation were it in the refrigerating systems, as well as causing restriction or plugging of the refrigeration system.

Moreover, another important feature of this invention is that there are very few moving parts. The moving parts of this construction being the cylinder 50 which is fixedly secured to the motor rotor 35, the rotor 5| which is rotatably mounted on the eccentric 41, and the divider 54. Because all Of these moving parts are suitably submerged in the lubricant and also sealed thereby, there will be very little wear of the parts and this construction will then tend toward long life and trouble-free operation.

The instant motor compressor combination unit, being formed of simple parts and readily available materials, lends itself to mass production manufacturing principles, thus affording a substantial saving in the manufacturing costs.

From the foregoing disclosure, it may be observed that we have provided an improved combination motor compressor unit which emciently fulfills the objects thereof as hereinbefore stated and which provides numerous advantages which may be summarized as follows:

1. structurally simple, efficient and durable;

2. Economical to manufacture and readily adaptable to mass production manufacturing principles; and

3. The provision of a combination motor compressor for refrigeration purposes employing an axial air gap motor as a power source thereby substantially effecting a reductionin the manufacturing costs thereof while providing an effective seal arrangement dividing the compressor into separate sealed compartments and further providing an improved arrangement of the elements of the compressor to obtain a minimum over-all coaxial dimension while maintaining a high efficiency of operation and thereby effecting a reduction in the cost of manufacturing over that of similar units of present manufacture.

While we have illustrated embodiments of our invention, many modifications may be made without departing from the spirit of the invention, and we do not wish to be limited to the precise details of construction set forth but wish to avail ourselves of all changes Within the scope of the appended claims.

We claim:

1. A combination motor-compressor unit comprising a housing divided by a partition wall into two compartments one of which being hermetically sealed and the other being defined by a removable bell-shaped cover, said motor comprising a stator and a motor rotor, said compressor comprising a stationary eccentric, a rotor mounted on said eccentric for relative rotation therebetween, a compression chamber, a rotatable cylinder eccentrically mounted in respect to said motor and surrounding said rotor and eccentric to define said compression chamber, an inlet leading to and an outlet leading from said compression chamber, and adivider located between said inlet and outlet carried by said cylinder for reciprocation in said compression chamber, said motor rotor being fixedly secured to said cylinder of the compressor and said cylinder being coaxially mounted for rotation responsive to the rotative forces of the motor rotor, and the elements of said compressor including the motor rotor being disposed in the hermetically sealed compartment while the stator is disposed in the other of said compartments with .the par tition wall being disposed between the stator and the motor rotor.

2. A compressor comprising a stationary eccentric, a rotor mounted on said eccentric for relative rotation therebetween, a compression chamber, axcylinder eccentrically mounted in respect to said rotor and for rotation and surrounding said rotor and eccentric to define said compression chamber, an inlet leading .to and an outlet leading from said compression chamber, a divider located between said inlet and outlet and carried by said cylinder and arranged for rotation therewith and having portions thereof in engagement with said rotor and arranged for reciprocation in said compression chamber responsive to the rotation of the cylinder and the action of the eccentric, an axial air gap electric motor comprising a stator and a motor rotor fixedly secured to said cylinder whereby said cylinder may be caused to rotate responsive to the rotative forces of the motor rotor, a housing for said compressor and motor, a partition wall dividing said housing into two compartments one of which being hermetically sealed and the other being defined by a removable bell-shaped cover, the elements of said compressor including the motor rotor being disposed in the hermetically sealed compartment while the stator is disposed in the other of said compartments with the partition wall being disposed between the stator and the motor rotor.

3. The combination of a casing, an axial air gap electric motor and a compressor both disposed within the casing, said compressor comprising a stationary eccentric, a rotor mounted on said eccentric for relative rotation therebetween, a compression chamber, a rotatable cylinder eccentrically mounted in respect to said rotor and surrounding said rotor and eccentric to define said compression chamber, an inlet leading to and an outlet leading from said compression chamber, a divider located between said outlet and inlet carried by said cylinder for reciprocation in said compression chamber, and said axial air gap motor comprising a stator and a motor rotor fixedly secured to said cylinder of the compressor, said cylinder being coaxially mounted for rotation responsive to the rotative forces of the motor rotor, said casing being divided by a partition wall into two compartments one of which being hermetically sealed and the other being defined by a removable bell-shaped cover, and the elements of said compressor including the motor rotor being disposed in the hermetically sealed compartment while the stator is disposed in the other of said compartments with the partition wall being disposed between the stator and the motor rotor.

4:. A compressor comprising a stud-like support member including a stationary eccentric, a rotor mounted on said eccentric for relative rotation therebetween, a compression chamber, a cylinder eccentrically mounted in respect to said rotor and for rotation and surrounding said rotor and eccentric to define said compression chamber; an inlet leading-to andan outletleading from said compression chamber, adivider located between said inlet and outlet and carried by said cylinder and arranged for rotation therewith and having portions thereof in engagement with said, rotor and arranged for reciprocation in said compression chamber responsive to rota- :tion of the cylinder and action of the eccentric,

in combination 'with-an axial air gap electric motor comprising a stator, a motor rotor fixedly secured to vsaid cylinder whereby said cylinder may be caused to rotate responsive to rotative forces of the motor;rotor, and means including aipartition wall disposed between the stator and the motor rotor and cooperating with thestudof the compressor and formed integral with said stud-like support member, a rotor mounted on said eccentric for relative rotation therebetween, a compression chambena rotatable cylinder eccentrically mounted in respect to said rotor and surrounding said rotor and eccentric and cooperating with said end plate to define said compression chamber, an inlet leading to and an outlet leading from said compressor, a divider located between said inlet and outlet and carried by said cylinder for reciprocation in said compression chamber, an electric motor comprising a stator carried by said closure member, a motor rotor fixedly secured to said cylinder, said cylinder being coaxially mounted for rotation responsive to the rotative forces of the motor rotor, a partition wall afiixed to said housing and said end plate and disposed between said stator and said motor rotor forming two compartments whereby to provide a hermetically sealed compartment for said compression chamber and motor rotor and a removable bell shaped compartment for said stator thereby permitting removal of said closure member and stator for access thereto without disturbing said compression chamber and motor rotor.

6. In a motor compressor assembly, the combination of a base and a cover therefor to provide a casing, a stud-like support member centrally disposed of the casing and having portions thereof formed to define a stationary eccentric, a bearing and an end plate which comprise parts of the compressor, a rotor mounted on said eccentric for relative rotation therebetween, a compression chamber and an eccentrically mounted cylinder surrounding said rotor and said eccentric and cooperating with said end plate to define said compression chamber, said stud-like support member having fluid conduits opening into said compression chamber and forming the suction side of the compressor, an inlet leading to and an outlet leading from said compression chamber, a divider located between said outlet and inlet carried by said cylinder for reciprocation in said compression chamber, an electric motor comprising a stator carried by said cover, and a motor rotor fixedly secured to said cylinder, said cylinder being coaxially mounted for rotation responsive to the rotative forces of the motor rotor, and a partition Wall secured to said housing and said stud-1ike sup- 11 port and disposed between said stator and said motor rotor to effectively seal the compression chamber from said stator.

7. A motor assembly comprising the combination of a housing with a closure member to provide a casing, a stud-like support member centrally disposed Of the casing and having portions thereof to define a stationary eccentric, a bearing and an end plate which comprise parts of the compressor, a rotor mounted on said eccentric for relative rotation therebetween, a compression chamber, a cylinder eccentrically mounted in respect to said rotor and surrounding said rotor and eccentric and cooperating with said end plate to define said compression chamber, said stud-like support having fluid conduits opening into said compression chamber and forming the suction side of the compressor, an inlet leading to and an outlet leading from said compression chamber, a divider located between said outlet and inlet carried by said cylinder for reciprocation, an electric motor comprising a stator carried by said closure member and a motor rotor fixedly secured to said cylinder, said cylinder being coaxially mounted for rotation responsive to the rotative forces of the motor rotor, a partition wall afiixed to said 12 housing and said end plate and disposed between said stator and said motor rotor forming two compartments to effectively seal the compression chamber from the stator, one being a removable bell shaped compartment for said rotor, said stud-like support extending through said closure member and having threads thereon, means defining a threaded aperture in said closure member cooperating with said stud-like support thus threadably securing said closure member to said housing whereby easy access is available to said stator.

LELAND K. WARRICK.

FRANK E. LA FLAME.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,992,348 Belden Feb. 26, 1935 2,172,500 Clements Sept. 12, 1939 2,415,011 Hubacker Jan. 28, 1947 2,541,906 Anderson Feb. 13, 1951 2,557,879 Lewis June 19, 1951 FOREIGN PATENTS Number Country Date 600,056 Germany July 13, 1934

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