US2117448A

US2117448A - Compressor

Info

Publication number: US2117448A
Application number: US577986A
Authority: US
Inventors: William G Pontis; William A Chryst; Carl H Kindl; Bayard D Kunkle
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1931-11-30
Filing date: 1931-11-30
Publication date: 1938-05-17
Anticipated expiration: 1955-05-17

Description

w. G. PON-ns Er AL May 17,- 193s.

5 Sheets-Sheet l COMPRESSOR Original Filed Nov. 30, 1931 May 17, 1938. w. G. PoNTls ET Al, 2,117,448

COMPRESSOR Original Filed Nov. 30, 1931 5 Sheets-Sheet 2 May 1 7, 1938. w. G. PON-'ns ET AL COMPRESSOR Original Filed Nov. 30, 1931 5 Sheets-Sheet 3 9:/3/ n j ,q

Jmcntow abbr vuur( May l7, 1938. w. G. PNTIS ET AL 2,117,448

COMPRESSOR Original Filed Nov. 30, 1931 5 Sheets-Sheet 4 l May 17, 1938. w.VG. PoNTls Er A1.l i 2,117,448

` coMFREssoR original Filed Nov. so, 1951 ssheets-sheet 5 f IVI, l* II'll gwuentou E1 cwww Patented May 1 7, `1938 -CODWRESSOR William G. Pontis, William A. Chryst, Cari H. Kindl, and Bayard D. Kunkle, Dayton, Ohio,

assignors, by mesne assignments, to Generai Motors Corporation, Detroit, Mich., a corpora tion of Delaware Application November 30, 1931, Serial No. 577,986 Renewed November 25, 1935 21 Claims.

This invention relates to improvements in motor compressors of the sealed unit type.

By sealed unit type is meant a device in which the compressor prime mover and the medium to be circulated are contained within a sealed housing.

It is among the objects of the present .invention to provide a sealed unit motor compressor of simple structure and design, compact, and capable of operating quietly and without substantial vibration. x

A further object of the pres-ent invention is to provide a lubricating system for the moving parts of the device, which system is so constructed and arranged that no appreciable amount of lubricant is discharged with the outiowng compressed medium.

These objects are attained by providing the combination of a stator, an armature, a cylinder contained within the armature, a piston, a shaft supporting the armature and the cylinder, and means for reciprocating the piston in respense to the movement of the rotor.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of one form ofthe present invention is clearly shown.

In the drawings:

Fig. 1 is a front elevation of the motor compressor having a horizontal shaft, and. is shown in a smaller scale than the other figures.

Fig. 2 is a cross sectional view of the motor compressor in an idle state, and is taken on the line 2--2 of Fig. 1.

Fig. 3 is a fragmentary sectional view of the motor compressor, and is taken on the line 3 3 of Fig. 2.

Fig. 4 is a fragmentary sectional view taken on the line 4-4 of Fig. 2 and is submitted for the purpose of emphasizing the unloading valves.

Fig. 5 is a fragmentary sectional view taken l on the line 5-.-5 of Fig. 2 and is submitted for the purpose of emphasizing thedischarge valves.

Fig. 6 is a fragmentary sectional view taken on the line 6 6 of Fig. 8.

Figs. 7, 8, and 9 are fragmentary sectional views through the piston 'and cylinder, showing different relative positions thereof.

Fig. 10 is a fragmentary sectional view taken on the line lil--IU of Fig. 5, and is drawn to an enlarged scale.

Fig. 11 is a fragmentary sectional view taken on line II-II of Fig. 10.

(Cl. B30-177) Fig. 12 shows .the cross section through a modi ed form of compressor having a vertical shaft.

Referring to the drawings the numeral 2li designates a housing comprising a cylindrical wall 2l and an end wall 22. The end wall 22 extends somewhat into the cylinder formed by the wall 2i and has a reverse curve 2Q near its mid-portion. Both walls are provided with spaced ribs 23 and 2t for cooling and reinforcing purposes. A cover plate 25 is provided for the housing, said plate having a machined surface 2l to engage the housing. Ribs 2t are formed on the cover for cooling and reinforcement purposes. counterbore 28 in the edge of the housing receives the machined part of the cover plate. The plate is secured to the housing by a clamping ring @il which has openings 32 for receiving screw-studs 35, which in turn are threadedly received by the housing. To insure a gas tight seal between the cover 25 and the housing, a gasket 35 is provided, said gasket being of any suitable materialv adapted to be pressed between the cover and housing.

Bosses it are provided on the housing, said bosses having provisions for the attachment of suitable shock or vibration absorbing pads 52.

The electrical equipment of the present device comprises a stator, having laminations 5t, seu cured together and anchored within the housing in any suitable manner. In the drawings the stator is shown press-fitted into the housing. The numeral 55 designates pins or rivets for holding the laminations clamped together between outside plates 53 and 54. A rotor, having laminations 56 which are held clamped between plates 51 and 58 by pins or rivets 59. is supported on a part of the compressor as will be described.

The terminals of the stator windings are connected to lead-in plugs 60 of any suitable design. The plugs in the present instance are hermetically secured in openings provided in the housing, said plugs having provisions on the outside of the housing for the attachment of the power lines.

The end wall22 of the housing has a recess 66 in its interior surface, said recess being substantially concentric of the cylindrical wall of the housing. The end cover 25 has a similar recess 61 substantially in coaxial alignment `with recess 66. A shaft 62 having

concentric end portions

63 and 64 and an eccentric portion 65 has its one end 63press-tted into the recess 61 of cover plate 25, so that a gas tight t obtains., The end 63 of the shaft is spaced from the bottom surface of the recess 6l, forming chamber 61a. Cover plate 25 has an interiorly threaded passage leading into said chamber 61a, and receives a lead-in pipe 86 as shown in Fig. 2. 'I'he other end 64 of shaft 62 fits snugly into the recess 66 so that the shaft is non-rotatably supported between cover 25 and end wall 22.

A cylinder block 10, comprising a cylindrical middle portion 1| and diametrically smaller end portions `12 and 15, is rotatably supported upon the concentric portions of the` shaft 62. One end of block 10 engages a machined surface 68 on the inner side of the end Wall 22, the other end of the block engaging the finished surface |1311 of end cover 25, thus preventing endwise movement of the block relative to the shaft. A transverse bore k13 is provided in the block 10 so that its axis intersects the axis of the shaft 62 at substantially right angles. A cylinder head 14 in the form of a ring is press fitted over the middle portion of the block 10, -thereby hermetically closing both ends of the. cylindrical transverse bore 13 in said block. The rotor laminations 56 are press fitted uponthe cylinder head 18. This secures the block 10 to the rotor laminations, thereby making the cylinder block a part of the rotor of the electric machine.

The chamber formed by the cylinder bore 13 in the block 10 and the cylinder head ring 14 has a piston 18 therein, forming compression chambers A and B. For purposes of description double acting piston 18 has two head portions, the faces thereof being designated by the

numerals

84 and 85, the former forming one wall of compression chamber A, the latter of compression chamber B. Piston 18 has a rectangular, transverse opening 19 through which the shaft 62 extends. Specifically the eccentric portion 65 of the shaft is positioned within theconlines of said piston opening. The dimension of the said opening 19 transversely of the piston is longer than the dimension thereof longitudinally of the piston. The piston head portion having face 84 has a passage |0| leading from said face into the opening 19 in the piston. A similar passage |02 is provided in the piston portion having .face 85. To prevent rotative movements of the piston within the cylinder, a pin 84a is press-fitted into the block 10 and extends into a longitudinal slot a in the surface of the piston, the slot being of sufficient length to permit ample longitudinal movements of said piston. I

' The piston, carried within the block 10 which is rota-ted about shaft 62 due to the fact that block 10 forms a part of the rotor of the electric machine, is therefore also rotated about the eccentric portion 65 of shaft 62. To translate this relativeA rotative motion of the piston and shaft into a reciprocatory movement of the piston, a cross head 11fis interposed between the piston and the eccentric portion 65 of the shaft. This cross head isa rectangular block 11 fitting upon said eccentric portion of the shaft and within the transverse opening 19 in the piston. The longer or transverse surfaces of the piston opening 19 slidably support the block 10, however, the shorter or longitudinal surfaces of the piston'opening 19 are spaced a greater distance than'the corresponding surfaces of block 11,

thereby providing the space between these block land opening surfaces and thus permitting the block 11 to move in the piston opening transversely of the piston.

The eccentric portion 65 of shaft 62 has a peripheral groove 9| of predetermined length.

This groove has a channel opening therethrough, which channel communicates with a longitudinal duct or passage in the shaft 62, which passage leads in the chamber 61a in end cover 25 as shown in Fig. 2. Cross head 11 has openings or

channels

93 and 94 provided in diametrically opposite sides respectively, these openings or

channels

93 and 94 providing communication between passages 0| and |02 and the peripheral groove 9| in proper recurrent intervals as will be described later. Due to the latter fact, the cross head has to maintain its relative position transversely of the piston which at all times maintains its relative position to the piston. For this purpose, pins and 96, press fitted into the piston 18 provide ngers 91 and 98, respectively, which have the cross head 11 interposed therebetween.

Within the chamber 61a there is provided a check valve 81 which permits fluid to flow from pipe 86 into the channel 90 under proper circumstances, but which will prevent a return flow of uid under all circumstances.

Preferably this valve comprises a disc 81, urged upon an annular valve seat formed by a ridge 88 on the bottom wall of recess 61. A spring 89 yieldingly urges the disc 81 upon its seat.

The cylinder head ring 14 has ports |01 providing for the discharge of fluid from the respective compression chambers into the housing. For purposes of preventing a back flow of compressed iiuid into the compression chambers, particularly when the respective piston ends are traveling on ltheir suction strokes check valves |03 and |06 have been provided in the cylinder head ring 14. These discharge valve mechanisms are constructed in the following manner, and due to the fact that 'both compression chambers are provided with similar discharge valves, only one will be described for the sake of brevity.

Adjacent the compression chamber A the cylinder head ring 14 is provided with an annular recess |05 in its outer surface, the bottom of said recess having an annular ridge |06, providing a seat for the disc valve |03, as clearly shown in Figs. 10 and 11. Ports |01, arranged in a circular, row preferably'on one side of its centers provide for communication between the compression chamber A and the compression side of the valve |03. Another recess ||0 cuts into the recess |05 and opens into the housing. A tubular member |09 is press-fitted upon the cylinder head ring 14, thereby covering'the recesses |05 and ||0. A blade spring 2 secured at one end to member |09 by a rivet ||3 has its free end engaging the disc valve 03, yieldingly urging it against its seat |06.

A baiile plate |8| is attached to the inner surface |13a of cover plate 25, so that a space is provided between the baille plate and end cover, this space being properly located so that the discharged fluid will engage the cover plate for cooling purposes. The baille plate has a flared extension |82 defining an opening into which the cylindrical member |09 extends. From this, it may be seen that annular member |09 not only supports the discharge valve spring ||2, but it also acts as a deflector, directing the discharged uid from ports |01 into the flared end of the rectly to the interior surface of the cover plate.V

'Ihe aforedescribed construction provides for a flow of fluid from any suitable source through pipe 86 into the chamber 61a after valve 31 has piston passage IDI, thus iuid from the supply been moved from its seat by fluid pressure. From the chamber 61aA the fluid flows through the shaft channel 90 and the passage leading into the` peripheral groove 9|. From groove 9| the fluid enters one or the other of the

passages

93 and 94, dependent upon the rrelative position ofthe cross head 11 to shaft 62.` If the fluid enters passage 93, then it proceeds through the piston passage into the compression chamber A, as the surface 84 of the piston moves away from the piston head ring 14. Upon reversal of this piston movement the communication between passages 93 and groove 9| is cut off and naturally the fluid in the compression chamber A will have pressure exerted thereupon, which, when sufcient, will force the fluid through ports |01 to move valve |03 from its seat, the iiuid then proceeding through recess ||0 along the inner surface |38 of baille ring |09 into the flared portion |32 of the baille plate |8I. Now the fluid enters the cooling space |95 between the baffle |8| and end cover 25 from whence said fluid will ow through opening |9| and pipe |92 to the desired device which is connected with pipe |92.

If on the other hand passages 94 and |02 are in communication with the` groove 9|, then the fluid flow is directed through the following path 94, |02, chamber B, ports |01 of said chamber, past valve |04 into chamber ||1, thence into the cooling space |05.

A feature of this invention resides in the `fact that the cross head 11 not only acts as a driving medium between the eccentric portion G5 of shaft 62 and the piston 19, but it also functions as a distributing valve for the uid flow into the proper compression chambers. As a distributing valve it operates in the following manner.

Referring to Figs. 3, 7 to 9 and at present particularly to Fig. 3, the piston is shown in its lower dead center position, considering chamber B the bottom chamber. Here the piston completely occupies the chamber B so that chamber A is at maximum capacity. In this position of the piston, passage 93 of the cross head is in full communication with the peripheral groove 9|, which under all conditions is the fluid supply groove. Passage 94 of the cross head is entirely cut of! from communication with the supply groove. The passage 93 of the cross head aligns with. the

groove 9| may flow through passages 93 and Inl into the compression chamber A. Communication between passages 9| and 93 was not eifected until the piston had been rotated by the cross head through a part of its cycle, thus piston 18,

' or more specifically its head surface `84 had been .the supply groove 9|, the other passage 93 being entirely cut olf therefrom.

Fig. 8 shows the piston midway between the cylinder heads. Chamber A is still cut oil from the supply groove 9|, while chamber B is still receiving a fluid supply therefrom.

In Fig. 9 the piston is shown in ayposition in which it has practically nished its compression stroke as regards to chamber A, while chamber 5 B is substantially charged to full capacity and ready to have the uid therein compressed. Now port 94 will be moved o'ut of register with the supply groove 9| and passage 93 will be moved into fluid intake relation therewith.

From the aforegoing it may be seen that while one compression chamber is being charged with fluid, .the fluid in the opposite chamber is having pressure exerted thereupon, and thus, due to this concurrent loading and discharging of uid a substantially constant flow of fluid under pressure into the housing is obtained.

To facilitate the starting of a compressor and particularly under load such as a back pressure, it is desirable to provide a device, which for a period will permit the prime mover to operate substantialb' free of said load. In the present instance "applicant has provided a centrifugal unloading device which circulates the uid flow so that, as one side of the piston discharges its lluid under pressure into the housing, the fluid vpressure in the housing will be introduced into the opposite cylinder to assist the piston in its movement to compress the fluid in the first mentioned chamber.

Each cylinder chamber has such a centrifugal unloading device, and because both of these are alike, only one of them will be described de` tailedly. A recess |23 is provided in block 10 alongside the cylinder bore 13 in the block. A passage |49 in the block 10 leads from the in- .terior of lthe housing into this recess. Another4 opening |41 in the block connects the compression chamber A with the recess |23. A cupshaped member |25 is press-fitted into said recess, a head portion on the cup-shaped member closingl the recess adjacent the cylinder head ring 14. In the head portion of the cup-shaped member there is provided a central passage |21, leading into the interior of the recess |23,vsaid passage communicating with a duct |45 which leads to the opening |41. An opening in the side wall of ,the cup-shaped member aligns with pas-` sage |49,.thus connecting the interior of the housing with the interior of thecup-shapedmember. A weight member |3I, centrally recessed as at |35 is slidably carried within the cup-shaped member. A valve pin |31, having a tapered end. has one end of a spring |4| engaging it, the other end of said spring is seated in a recess in the interior surface of the head` of the cupshaped member. Valve pin |31 is substantially in coaxial alignment with the 'passage |21. Spring |4| yieldably urges the valve pin |31 into the bottom of the recess |35 of the weight block |3I, thereby maintaining its tapered end in spaced relation with the passage |21.

The parts of the unloading device for compression chamber B correspond to the parts of the unloading device for chamber A as follows: |24 like |23; |50 like |49; |48 like |41; |26 like |25; |28 and |46 likeV |21 and |45, respectively; |32 like |3|; |38 and |42 like |31 and |4|, respec tively; and |36 like |35. u

These unloading devices operate as follows. Assuming that a pressure exists within the housing 20, and it is desired to start the compressor, the circuit through the electric machine is then closed, causing rotation of the rotor and consequenny of the cylinder block 1o which forms a 7 lcompression chambers.

part of the rotor. As has been described before,

-rotation of the block 10 causes reciprocation of .communication with the interior of the housing 20 through passages |41, |45, |21, and |49, the other through passages |48, |46, |28, and |50. If chamber A is discharging fluid under pressure through the aforementioned ducts or passages into the housing, then the housing is exerting pressure into the chamber B through its respecltive passages, and consequently a counter-balance of pressures on opposite sidesof the piston obtains, thereby providing a substantially free acting piston.' The motor may accelerate to a predetermined speed substantially without load.

The said predetermined speed having been at` tained, the weight members |3| andJ |32 will be thrown outwardly toward the closed end of the respective cup-shaped members |25 and |26, thus the respective valve pins |31 and |38 will be moved to close the passages |21 and |28 respectively, and thereby the chambers 'A and B are completely shut ol from communication with the interior of the housing through their respective pressure relieving passages.

'I'he necessary lubricating system for the device will now be described; referring more particularly to Figs. 1 to 3, the motor housing 20 provides a supply of lubricant |6I. A nipple |62 is threaded with one end into a boss |63 of the motor housing 20 and with its other end into an elbow |64, which also threadedly receives a second vertically directed nipple |65. A cap |65a is threaded upon the nipple |65 and prevents -lubricant in the housing 20 from being discharged. The length of the nipple |65 is-such that when the oil reaches a proper level in the housing, the nipple |65 will overflow.

The coverg25 provides a lug |66, interiorly recessed to receive a pivot member |61 for rotatbakelite or like material, to eliminate noise while cooperating with a gear ring |69, press-fitted upon a reduced portion |10 of .the cylinder block 10. 'I'his gear ring |69 which is to drive the lubricant conveying gear |68 is held against lateral movement by inter-position between the adjacent end of the cylinder block 10 and the bottom |1| of an annular recess |12 in the end cover 25. The gear |68 is received within an annular recess |13 Yand its inner face is flush with the finished surface |13a of the cover 25. A retainer plate |14, preferably screwed on the inner'surface |13a of the cover 25 as at |15, retains the gear |68 in position and also obstructs the passage of lubricant from the voil carrying tooth spaces into the motor housing. A groove |16 in the bottom |1| of the annular recess |12 receives the lubricant lifted by the gear |68. A longitudinal groove |11 in the outer surface of shaft 62 transports the lubricant from groove |16 to the piston opening 19. The oil then passes through the` piston opening 19. A longitudinal groove |18 at the opposite end of the shaft con-A veysrthis lubricant from the piston opening 19 being thrown against'the'windings, and cause the lubricant to pass over the end wall 22 and be cooled in returning to the housing.

Some of the oil will naturally leak into the compression chambers and intermix with the fluid therein and be discharged therewith into the housing. As has been mentioned before, baille ring |09 directs substantially all of the discharged fluid into the cooling space |85. As this lubricant containing fluid strikes the substantially cool end cover 25 and baille plate |8I, the lubricant in the fluid will be condensed. The condensed oil will flow to the lubricant supply, thereby passing through a depreion |82a in the baille plate |8I.

The fluid discharged from the housing is therefore comparatively free of oil vapor. This is a very desirable feature of this as well as of all.

compressors, since otherwise oil vapor, carried by the discharged fluid would condense along the inner wall of the discharge pipe |92 and settle therein, forming oil mud. In the space of time this oil mud would accumulate to such an extent that it would finally obstruct the free passage of compressed fluid through the pipe |92. l

In Fig. 12 a modified form of compressor is shown. In this device shaft 2| l, corresponding to shaft 620i the main construction, is so supported andvarranged in the housing 202 so that .the rotor is adapted to rotate in a vertical position. The modified compressor, disclosed in Fig. 12 is practically of the same construction as the one described. Thus the prime mover and the operating parts of the modified form of compressor are substantially identical to the respective parts of the main construction, only the oiling system and the cooling baffle necessitating essential constructive changes which will be dealt with now.

In this construction the end wall 20| of the housing, which now forms the bottom thereof has an annular extension 206 coaxially of the rotor, this extension being recessed to receive the end 2|0 of shaft 2| A plate 205, centrally' recessed,

is press-fitted upon the annular extension 206.A

The inner edge of said extension and the surface of the plate 205 which is substantially flush with said edge provide an end thrust bearing for the cylinder block 204. The lower end of the cylinder block has an annular cut-away portion,

whichA together with the plate 205 and the inner surface ofthe cylinder head ring 14 forms an annular chamber 2|3. The cylinder head ring has a spiral groove 2|5 in its outer, peripheral surface adjacent the lower end thereof. The chamber 2 I3 is in communication with the lowest convolution 2|4 of the spiral groove 2|5 through a plurality of ducts 2|6 inthe cylinder head ring. A radial groove 201 is cut in the inner surface of the end wall 20| and connects the convolution 2 4 ofthe spiral groove 2|5 with a recess 208 in the central portion of plate 205. The recess 208 is in communication with a longitudinal groove 209, provided in the outer surface of the shaft portion 2|0. Passage 209 leads directly to the piston opening 19. Lubricant from the lubricant supply within the housing must pass through an annular filter 224 comprising an annular screen 222l fitting over an annular extension 223 within the housing, said screen being covered by any suitable illtering material 224. After passing through the lter. the oil enters a duct 2|2 in the end wall of the housing, said duct leading into the annular chamber 2|3. The lubricant, vhaving entered chamber 2|3, will be ejected through openings :sok

aliases or ports 2&6 by a centrifugal force, entering the convolution 2id of the spiral groove 205 under pressure. The characteristic of the spiral groove 2 it is such that it will force said lubricant downwardly into the radial groove 2M, from whence the lubricant is forced through recess 208 and longitudinal channel 229 into the cross head containing piston opening I9. From this opening the fluid will pass through a longitudinal channel tdda in the upper end of the shaft 2l l. From this channel the lubricant will enter radial grooves 2id and 2H, formed in the upper end of the cylinder block 2M, and is then thrown out onto a plate 2id rotating with the rotor. The plate 2id extends over and beyond the edge of the inner opening in the baffle plate 22d, which is secured to the cover plate 25 of the housing by screws 220m, so that the lubricant on plate 2 it is thrown upon the bame plate 22h from which it drops into the main lubricant supply. To pass the rotor on its way from bame plate 22u to the lubricant supply, the lubricant flows through passages 224 formed by recesses in the annular wall of the housing. In passing along the recesses 22i of the ribbed annular wall, the lubricant is cooled whereby the main lubricant supply is maintained at a substantial proper temperature. A lug 221 of the housing 202 provides a'threaded hole 22e wherein a nipple 225 is received, said nipple also being threaded into an elbow 228. Another nipple 22@ is also threadedly received by the elbow 222. Lubricant may be poured into the housing from the outside through nipple 229, elbow 228 and nipple 225. A cap 23d threaded upon the nipple 22h prevents oil in the housing from being discharged. l

The heme ring 235 is slightly flared as clearly shown in Fig. 12. This is for the purpose of utilizing centrifugal force to transport the condensed oil on the interior surface of said baille ring, which was mixed with the discharged compressed huid in the form of oil vapor. When the condensed oil reaches the upper edge of said baffle ring it will be thrown onto the cooling baffle 222 and follow the already described course of the circulating lubricant.

While the form of embodiment of the present invention constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the present invention.

at is claimed is as follows:

ll. In a motor compressor, the combination of a sealed housing; a stator; a rotor; a cylinder block having a cylinder bore therein carried within the rotor; a shaft having concentric and eccentric portions, the cylinder block being rotatably carried by the concentric portion of the shaft; a double acting piston in said cylinder bore forming compression chambers therein, said piston engaging the eccentric shaft portion and being reciprocated thereby in response to rotation of the cylinder about said shaft; ducts provided in the piston and shaft and cooperating to introduce a huid medium into the compression chambers; openings in the chambers having valve seats formed on one side thereof; and spring-loaded valves yieldingly urged against said seats and operated at a predetermined pressure to provide connication between the sealed housing and the compression chambers.

2. In a motor compressor, the combination of a sealed housing; a stator; a rotor; a cylinder bloclr having a cylinder bore therein carried within the rotor; a shaft having concentric and eccentric portions, the cylinder being rotatably carried by the concentric portion of the shaft; a double acting piston in said cylinder bore forming compression chambers therein, said piston engaging the eccentric shaft portion and being reciprocated thereby in response to rotation of the cylinder about said shaft; ducts provided in the piston and shaft, and cooperating to introduce a huid medium into the compression chambers; a check valve in one of said ducts adapted to admit fluid into the compression chambers in response to a predetermined pressure thereon; valved ports opening out of the chambers for the discharge of the compressed uid from said compression chambers, said check valve and ducts admitting fluid to one of said chambers while one of said valved ports permits the discharge of compressed fluid from another chamber into said housing.

3. In a motor compressor, the combination of a sealed housing adapted to carry fluid under pressure; a stator; a rotor; a cylinder block; a cylinder head forming a piston chamber in said block; a double acting piston in said chamber forming compression chambers therein; a shaft having an eccentric portion operatively connect-4 ed with said piston to operate it in response to rotation of the cylinder block upon said shaft; channels in the shaft and the piston adapted to be aligned to provide a fluid flow into the piston chambers; outlet ports in the cylinder head; valves for said channels and ports; ducts connecting the compression chambers with the interior of the sealed housing; and means adapted to close said ducts in response to a predetermined rotary speed of the cylinder block.

d. In a motor compressor unit, the combination of a sealed housing; a stator; a rotor; a cylinder block carried by the rotor said block having a. transverse bore; a cylinder head on the block closing the ends of said'bore to form a piston chamber; a double acting piston in said chamber forming compression chambers therein; a shaft having an eccentric portion operatively connected with said piston to reciprocate itin response to rotation of the cylinder block upon said shaft; channels in the shaft and piston adapted to introduce fluid into the piston chambers; outlet ports in the cylinder head; valves for said channels and ports, and centrifugal means normally connecting the cylinder cham` bers and adapted at a predetermined speed to discontinue the said connection.

5. In a motor compressor. the combination of a. sealed housing adapted to carry fluid under pressure and containing; a stator; a rotor; a

cylinder block supported within the rotor; a head for closing the cylinder block; a double acting piston in the cylinder block forming compression chambers therein; a shaft having an eccentric portion for rotatably supporting said piston and operating it in response to rotation of the cylinder block upon said shaft; channels in the shaft and piston for introducing fluid into the compression chambers; outlet ports in the cylinder head; valves for said channels and ports; ducts connecting the compression chambers with the interior of the sealed housing; and centrifugal means normally, yieldably urged to maintain connection between the cylinder chambers and housing and adapted at a predetermined speed to discontinue the said connection.

6. In a. motor compressor, the combination ci a sealed housing adapted to carry compressed duid and containing; a stator; a rotor; a block carried within the rotor and providing a cylinder; a cylinder head ring on said block; a double acting piston in said cylinder forming compression chambers therein; a stationary shaft rotatably supporting the cylinder block and piston Aand having means for reciprocating the piston to close said ducts.

7. In a motor compressor, the combination comprising, a housing; a cylinder block having recesses and a cylinder bore therein; a cylinder head forming a piston chamber in said block; a double acting piston in said bore forming compression' chambers therein; a shafty for rotatably supporting the cylinder block, said shaft having an eccentric portion for drivingly engaging the piston; means for causing relative rotation-be tween the shaft and the cylinder block, whereby the piston is caused to slide within the chamber; a low pressure fluid supply; means actuated in response to relative rotation between the cylinder block and the shaft for providing communication between said fluid supply and the cylinder chamber; pressure responsive valves carried by the cylinder block for discharging compressed fluid from 'the compression chambers; meansproviding direct fluid communication between said compression chambers andrvalves mounted in said recesses for rendering the last mentioned means ineective when a predetermined rotary speed of the cylinder block is reached, said valves including, weight members slidably mounted within said recesses so as to be moved by centrifugal force, valve pins actuated by said weight members, and springs for resisting the centrifugal force on said weight members and valve pins.

8. In a motor compressor, the combination comprising, a housing; a cylinder block having recesses and a cylinder bore therein; a cylinder head forming a piston chamber invsaid block; a double acting piston in said bore forming compression chambers therein; a shaft for rotatably supporting the cylinder block, said shaft having an eccentric portion for drivingly engaging the piston; means for causing relative rotation between the shaft and the cylinder block, whereby the piston is caused to slide within the chamber; a low pressure fluid supply; means actuated in response to relative rotation between the cylinder block `and the shaft for providing communication between said fluid supply and the cylinder chamber; pressure responsive valves carried by the cylinder block for discharging compressed fluid from the compression chambers; means providing direct uid communication between said compression chambers and valves mounted in said recesses for rendering the last mentioned means ineffective when a predetermined rotary speed of the cylinder block is reached, said valves including, centrally recessed weight members slidably mounted within said recesses so as to be moved by centrifugal force, valve pins mounted in the central recesses in said weight members and adapted to be actuated thereby, and springs 'forresisting the centrifugal force on said weight members.

9. In a motor compressor, the' combination comprising, a housing; a cylinder block having recesses and a cylinder bore therein; a cylinder head forming a piston chamber in said block; a

double acting piston in said bore forming compression chambers therein; a shaft for rotatably supporting the cylinder block, said shaft having an eccentric portion for drivingly engaging the piston; means for causing relative rotation between the shaft and the cylinder block, whereby the piston is caused to slide within the chamber; a low pressure fluid supply; means actuated in response to relative rotation between the cylinder block and the shaft for providing communication between said fluid supply and the cylinder chamber; pressure responsive valves carried by the cylinder block for discharging compressed fluid from the compression chambers; means providing direct fluid communication between said compression chambers and valves mounted in said recesses for rendering the last mentioned n means ineffective when a predetermined rotary speed of the cylinder block is reached, said valves including, cup-shaped members press fitted into said recesses and each having a central passage therein, weight members slidable within said cupshaped members and moved therein by centrifugal force, valve pins actuated by said weight members and adapted to close said central passages,Y

and springs urging said weight members to resist the centrifugal force on said weight members.

l0. In a motor compressor, the combination comprising, a sealed housing; a cylinder block having recesses and la cylinder bore therein; a cylinder head forming a piston chamber in said block; a double acting piston in said bore forming compression chambers therein; a shaft for rotatably supporting the cylinder block within said housing, said shaft having an eccentric portion for drivingly engaging the piston; means for causing relative rotation between the shaft and the cylinder block, whereby the piston is caused to slide within the chamber; a low pressure fluid supply; means actuated in response to relative rotation between the cylinder block and the shaft for providing communication between said fluid supply and the compression chambers; pressure responsive valves carried by the cylinder block for discharging compressed fluid from the compression chambers into said housing; and means for relieving the pressure ou the end surfaces of said double acting piston until a predetermined operating speed is reached.

l1. In a motor compressor, the combination comprising, a sealed housing; a cylinder block having recesses' and a cylinder vbore therein; a cylinder head forming a piston chamber in said block; a double acting piston in said bore forming compression chambers therein; a shaft for rotatably supporting the cylinder block within said housing, said shaft having an eccentric portion for drivingly engaging the piston; means for causing relative rotation between the shaft and the cylinder block, whereby the piston is caused to slide within the chamber; a low pressure fluid supply; means actuated in response to relative rotation between the cylinder block and the shaft for providing communication between said fluid supply and the cbmpression chambers; pressure responsive valves carried by the cylinder block for discharging compressed fluid from the compression chambers into said housing; and means for equalizing the pressure on the4 end surfaces of said double acting piston until a predetermined operating speed is reached.

l2. In a motor compressor, the com/bination lli comprising, a sealed housing; a cylinder block having recesses and a cylinder bore therein; a cylinder head forming a piston chamber in said block; a double acting piston in said bore forming compression chambers therein; a shaft for rotatably -supporting the cylinder block within said housing, said shaft having an eccentric portion for drivingly engaging the piston; means for causing relative rotation betweenV the shaft and the cylinder block, whereby the piston is caused to slide within the chamber; a low pressure fluid supply; means actuated in `response to relative rotation between the cylinder block and the shaft for providing communication between said uid supply and the compression chambers; pressure responsive valves carried by the cylinder block for discharging compressed fluid from the compression chambers into said housing; and means for admitting fluid from within said sealed housing to the end surfaces of said double acting piston until a predetermined operating speed is reached.

13. In a motor compressor for compressing a fluid medium, the combination comprising, a rotary cylinder block having a cylinder bore and recesses therein; cup-shaped members press tted into said recesses, said cup-shaped members each having a passage in the end thereof; means proriding communication `for said medium from said cylinder bore through said passages to the outside of said cylinder block; weight members slidable in said cup-shaped members and moved therein by centrifugal force; valves actuated by said weight members and adapted to close said passages; and springs for opposing the centrifugal force, and urging said valves away from said passages. v Y

1d. lin a motor compressor, an unloading `valve for reducing the load on the motor at start; and comprising in combination, a cup-shaped member having a passage therein; a weight member having a recess therein and slidable within said cup-shaped member; a valve pin having a head thereon and disposed within said recess, said pin being movable with said weight memberto close said passage; and a spring interposed between said head and said cup-shaped member.

15. In a motor compressor, the combination comprising, a sealed housing having lubricant and fluid cooling surfaces; a cylinder block having a cylinder bore therein; a cylinder head forming a piston chamber in said block; a piston in said bore forming a compression chamber therein; a shaft for rotatably supporting the cylinder block, said shaft having an eccentric portion for drivingly engaging the piston; means for causing relative rotation between the shaft and the cylinder block, whereby the piston is caused to slide within the chamber; a low pressure fluid supply; means including said shaft and piston for intermittently providing communication between said fluid supply and said compression chamber; a lubricant supply in said housing; means also including said shaft for providing a communicating passage for said lubricant from said supply to said piston; means providing a return passage for said lubricant over a cooling surface; valves for controllingthe discharge of compressed fluid from said compression chambers to within said housing; and a baffle cooperating with said valves and within said housing for causing the discharged iiuid to contact the cooling surfaces.

i6. in a motor compressor, the combination comprising, a sealed housing having lubricant and duid cooling surfaces; a cylinder block having a cylinder bore therein; a cylinder head forming a piston chamber in said block; a piston in said bore forming a compression chamber therein; a shaft for rotatably supporting the cylinder block, said shaft having an eccentric portion for drivingly engaging the piston; means for causing relative rotation betweenthe shaft and the cylinder block, whereby the piston is caused to slide within the chamber; a low pressure uid supply; means including said shaft and piston for intermittently providing communication between said fluid supply and said compression chamber; a lubricant supply in said housing; means also including said shaft for providing a communicating passage for said lubricant from said supply to said piston; means providing a return passage for said lubricant over a cooling surface; valves for controlling the discharge of compressed fluid from said compression chambers to within said housing; baffles cooperating with said valves and within said housing for causing the discharged uid to contact the cooling surfaces, said bafiiescomprising an annular member mounted on vsaid cylinder head and a baiiie plate surrounding a portion of said annular member and attached to said housing and spaced therefrom.

17. In a motor compressorV having a sealed housing, a shaft supported by said housing, a rotor, a cylinder block within said rotor and having a cylinder bore therein, a stator within said housing surrounding said rotor and having windings thereon, and a piston mounted in said bore and4 having an opening therein, a lubricating system comprising in combination, a lubricant supply chamber formed by said housing; communicating passages for the lubricant flow to and from said opening; a lubricant conveyor carried by said housing and adapted to convey lubricant to one of said passages; said opening providing a lubricant supply chamber for said piston: means communicating with another of said passages for returning the lubricant to said supply chamber; and means cooperating with said last mentioned means for preventing said lubricant from being thrown against the windings.

18. In a motor compressor, a rotor assembly adapted to be mounted on a stationary shaft having a fluid conducting opening therein, comprising, in combination, a substantially cylindrical cylinder block having an axially extending shaft opening and a transversely extending cylinder bore therein; a piston in said cylinder bore having an opening therethru through which the shaft extends, said piston also having fluid conducting openings therethru; a member within the rst mentioned opening in said piston for drivingly connecting the shaft and piston, said member having fluid conducting openings therein for intermittently establishing fluid communication between the opening in said shaft and those in said piston; a sleeve member fitted over said block to provide a cylinder head and forming compression chambers at each end of said piston, said sleeve having fluid outlet openings therein communicating with said compression chambers; a second sleeve secured to said sleeve member and providing a fluid baflle for defiecting the oW of fluid from the compression chambers; spring urged valves for controlling the discharge of uid from the compression chambers; and a motor rotor surrounding said sleeve member and drivingly secured thereto.

19. A compressor unit having a casing enclosing a body of oil and into which the high pressure uid is discharged and having a flat plate wall, a rotating discharge part of said compressor tti in said casing rotating adjacent to and on an axis perpendicular to said wall, an outlet from the casing in said wall thereof, and a flat baille parallel to said wall and surrounding said rotating part and having a surface adjacent -said outlet, said rotating discharge part of said compressor discharging into the space between said at plate wall and said baille.

20. A motor-compressor unit including a substantially cylindrical casing having an end Wall, an outlet in said end wall, a baille in front of said end wall and having a circular opening, a compressor Within said casing having a rotating discharge part extending into said circular opening.