US2071870A - Motor compressor unit - Google Patents

Description

Feb. 23, 1937. E. w. BALLENTINE 2,071,870 7 MOTOR COMPRESSOR UNIT Filed Sept. 3, 1955 s Sheets-Sheet 1 m 3 Q N Feb. 23, 1937. E. w. BALLENTINE 2,071,870

MOTOR COMPRESSOR UNIT Filed Sept. 3, 1955 s Sheets-Sheet 2 Feb. 23, 1937. E. w BALLENTINE MOTOR COMPRESSOR UNIT Filed Sept. 3, 1955 3 Sheets-Sheet 3 ZZUZMW 7Z6 P Feb. 23,1937

UNITED STATES PATENT OFFICE MOTOR comsssoa UNIT flollofllllllois Application September 3, 1935, Serial No. 39,034

Claims.

This invention relates to improvements in motor compressor units and, more especially, such a device particularly adapted for compressing or pumping fluids. The device is particularly use-- ful, for example, for compressing a iluid used in refrigerating apparatus, such as freon, methyl chloride, or the like. 7

Among the features of my invention is the provision of a single bearing for supporting the 10 motor shaft, said shaft also carrying the crank operating the compressor. This feature makes a very compact unit with a consequent saving in material. Another advantage of this feature is that the bearing is made to lie inside of the 16 space occupied by the stator of the motor. thus aflecting a further economy in space with resulting compactness and strength.

My improved unit is made of three principal castings, one of these being the cylinder block orcornpressorcasting. Ontopofthisisasecond casting operating the main bearing and the stator. Over this is a third casting acting both as a housing and as a cast rotor.

Another feature of my invention is the provision of a single long bearing with a seal at the outer end thereof, thus increasing the eiiiciency of the seal.

My improved device is especially adapted for operating on a refrigerant having a lubricant carried thereby or mixed with the same so that said lubricant is available for oiling both the motor and the compressor. I have provided improved means for circulating the oil.

Another feature of my invention is the provisionofamechanicalsealthatactsalsoasa thrust bearing for supporting the rotor.

Another feature of my invention is the provision of a suction line entering through the side wall of the cylinder head casting so that it is necessary to seal only the low pressure side of the system.

My improved unit is so designed that it is relatively inexpensive to manufacture. This is due largely to the fact that all the machining is either flat or round work.

Another feature'of my invention is the utilization of an internal stator induction motor to elect extreme compactness and simplicity in construction, assembly and operation.

Other features and advantages of my invention willappearmorefullyaslproceedwithmyspeciflcation.

In that form of device embodying the features of my invention shown in the accompanying III Figure 1isatopplanview;l"ig.2isaviewin side elevation; Fig. 8 is a vertical sectional view: and Pig. 4 is a view taken as indicated by the line 4 of Hg. 3.

As shown in the drawings, A indicates a compressor casting or cylinder block. On top of this is fastened a second casting B which carries the central upwardly projecting tubular member III. This tubular member carries on its outside the stator of the motor and on its inside the shaft to be hereinafter described. C represents the third principal casting carried by the shaft and also serving as a rotor. This casting also serves as a housing for the motor.

The casting A is of cup or reservoir form open at the top and provided with four radial inwardly projecting cylinders I I, I I and has cooling flns I! on its outside. Inside of the cylinders are the pistons II. ll, ll indicate connecting rods, one of these, It, being keyed to the crankbearing I! by the key It to act as a master crank. il indicates the crank-pin carried on the lower end of the shaft i8 and it indicates a counterweight.

The fluid to be pumped is taken into the reservoir portion of crank-case 20 through the inlet pipe 2| and enters the cylinders ll through the milled intake ports 22. These ports preferably extend through an arc of about and are so located that they are just uncovered when the piston is at the limit of its stroke inwardly.

The outlet ports 23 are arranged in the outer ends of the cylinders and they are adapted to be closed by outlet valves 24 in the form of steel discs held on their seats by the springs 2|.

The casting B comprises a circular plate 28 provided with an upstanding rim 21 and the central upstanding sleeve Ill. The plate 26 serves as a closure for the upper side of the crank-case 20. The casting B is bolted to the casting A by the bolts 22. The shaft I. is iournaled on the inside of the sleeve or tubular member II and there is preferably provided a bushing 29. This may be made of suitable bearing metal and is provided with vertical oil return grooves 28'. The upper end ofthe bushing 20 is provided with an oil outlet port 2!" opening into an annular recess or manifold 2l joining the upper ends of the vertical oil grooves 29''. The shaft II is provided with a spiral groove ill designed to pump oil upwardly to lubricate the bushings, the oil being permitted to escape through the hole 29" and thence return through the grooves 29- to the crank-case. The lubricant is carried by the refrigerant and is availableforcilingboththemotorandcompressor.

It enters the crank-case with the refrigerant, thus lubricating the cylinders, wrist pins. crankpin and other working parts of the compressor. some of it is also pumped up by the oil groove 33, as explained above, to lubricate the shaft bearing. It returns to the crank-case through the grooves 23", as described above.

The tubular member ll carries on its outside the stator 3| 0! an induction motor. This need not be described in detail as the construction and operation oi. stators and rotors oi electrical induction motors are well known and may be made in a variety of forms. As here shown, the stator 3| may include a plurality of iron plates 3|- provided with central holes and carried on the tubular member ID. 3| may indicate the windings of the stator. The entire stator and rotor are shown more or less diagrammatically and, consequently, the wires and wiring connections are omitted. It is to be understood that suitable wiring connections are provided to the stator 3|.

The casting C in the shape of a bell is pinned to the upper .end of the shaft l8 by the pin 32. This casting carries at its periphery the rotor 33 of the induction motor.

A seal for the shaft i8 is provided by the cupshaped member 34 mounted on the shaft l8 and sealed thereto by suitable packing material 35 pressed into the cup 34 by a spring 36 pressing against the washer 31. The lower edge of the cup 34 is sealed against the upper edge of the bushing 29 by providing smooth gas-tight surfaces. The lower edge of the cup 34, for example, may be hardened polished steel and rest on the upper end of the bushing 29. The upper end of said bushing may be suitable bearing metal and smooth in order to make a gas-tight seal with the lower end of the cup 34 rotating on it. The cup 34 and sealing material 35 rotate with the shaft l8. It will be seen that the long bearing sleeve 29 sealed on top as above described, makes a very effectual seal for the crank-case 2U.

33 indicates the exhaust pipes communicating with the exhaust ports 23. The pipes 38 may be connected by a suitable header (not shown) if desired.

The upper end of the shaft l8 may carry a fan 39 to assist in cooling the unit.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is my intention to claim all novelty inherent in my invention as broadly as permissible, in view of the prior art.

What I claim as new, and desire to secure by Letters Patent, is:

1. A motor compressor unit, including in combination: a cup-shaped casting forming a cylinder block and crank-case with the upper side open; compression mechanism in said casting; a second casting fastened to the compressor casting and closing the open side oi the crank-case, said second casting carrying a tubular bearing member; a shaft iournaled in the tubular member of the second casting and provided with driving connections to the compressing mechanism: a motor stator carried on the tubular member of the second-mentioned casting and surrounding said tubular member; and a third casting secured to the shaft and provided with a motor rotor whereby the compressing mechanism is actuated.

2. A device as claimed in claim 1, with a seal between the shaft and the tubular member adjacent the third casting.

3. A motor compressor unit, including in combination: a compressor casting forming a cyl inder block and crank-case of reservoir form with the upper side open; compression mechanism in said casting; a second casting fastened to the compressor casting and closing the open side of the crank-case, said second casting carrying a tubular member; a shaft journaled in the tubular member of the second casting and provided with driving connections to the compressing mechanism; a motor stator carried on the tubular member of the second-mentioned casting; and a third casting carried by the shaft and provided with a motor rotor surrounding the stator whereby the compressing mechanism is operated.

4. A device as claimed in claim 3, with a seal between the shaft and the tubular member adjacent the third casting.

5. A motor compressor unit, including in combination: a compressor with a crank-case and radial cylinders; pistons in the cylinders; connecting rods attached to the pistons; a centrally arranged tubular bearing member; a shaft journaled in the tubular member; a driving connection between one end of the shaft and the con-- necting rods; a motor stator surrounding and carried by the tubular member; and a motor rotor attached to the other end of the shaft and surrounding the stator.

6. A motor compressor unit, including in combination: a compressor with a crank-case and radial cylinders; pistons in the cylinders; connecting rods attached to the pistons; a centrally arranged tubular bearing member at one side of the crank-case; a shaft journaled in the tubular member; a driving connection between one end of the shaft and the connecting rods; a motor stator surrounding and carried by the tubular member; and a motor rotor attached to the other end of the shaft and surrounding the stator.

EARLE W. BALLEN'I'INE.

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