US 2100716 A
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Description (OCR text may contain errors)
Nov. 30, 1937. c. E, L. LIPMAN 2,100,716
MOTOR COMPRESSOR UNIT FOR REFRIGERATING APPARATUS Filed April 3., 1935 '2 Sheets-Sheet? Patented Nov. 30,1937
MOTOR-COMPRESSOR UNET FR REFRG- ERATING APPARATUS Carl E. L. Lipman, Chicago, lili., assigner to Lipman Patents Corporation, Chicago, 1li., a corporation of Delaware Application April 3, 193e, seriali Ne. ecarte 11 claims.
This invention relates generally to refrigerating apparatus particularly adaptable for house-- hold refrigeration, although it will be manifest that many of the novel features of my invention are capable or" embodimentin apparatus suitable for purposes other than that of refrigeration.
More specifically my invention relates to hermetically sealed refrigerating units in which the lubricating oil is utilized to lubricate and cool the driving motor, a portion of the oil at least being cooled to remove the heat units absorbed therein.
An object of my invention is to provide means automatically operable to control the cooling of the oil in such a Ymanner as to maintain or quickly restore a proper working temperature of the unit which will ,prevent overheating of the motor, and alsoprevent undue absorption of refrigerant in the oil. Another object is to improve the motor construction so as to facilitate the absorption of heat units therefrom by the circulating oil and thereby increase. the life and efficiency o f 'the motor.
Other objects and inherent advantages of' invention will be appreciated as the same become better understood froman examination'of this specification and claims in connection with.the accompanying drawings therein.
Fig. 1 is a schematic view of a complete refrigerating apparatus with the motor compressor unit-shown in section,
Fig. 2 is a fragmentary section of the base of the motor compressor unit with the oil strainer removed, Y
Fig. 3 is a plan of the thermostatically controlled valve,
Fig. fi isa vertical central section through the thermostatically controlled valve taken approxlmately along line I-Il of Fig. 3,
40 Fig. 5 is a vertical section through the therl mostatically controlled valve taken approximately along line 5--5 of Fig. 4, Fig. 6 is a fragmentary plan of the motorv stator, and
Fig. 7. is a fragmentary side elevation of the motor stator. f A
Referring now to the drawings in more detail, and particularly to the diagrammatic lay out shown in Fig. "l, reference character i indicates 50 generally the hermetically sealed unit in which the operating parts, all in the apparatus to be fdescribed, aredisposed and into which the compressor discharges the refrigerant compressed 55' thereby. The refrigerating medium is delivered from the sealed casing' through a pipe 2 to a condenser 1% cooled by fan 4 which may also circulate air through the unit l, if desired, from which the condensed refrigerant is conveyed by a pipe 5 to a float chamber 6, and thence through pipe 'l to an expander or evaporator 8 from which the expanded refrigerant is conducted through pipe 9, check valve ll, and pipe l2 to the suction side of the compressor.
It should be understood that While l have illustrated a conventional flooded type of refrigerating system, including an evaporator, any other type of system including an expansion valve or expander may be employed if the system is operated on some other principle than the flooded system principle.
The motor compressor unit shown 4in section (Fig. l) comprises generally a base i3 providing an annular oil sump and having a central table i4 shaped to provide a central oil well l5 in the interior thereof. The table constitutes a support for a pump housinor comprising a disc or base plate IB formed in the bottom of the housing, and an annular member i'l forming the 'sidewalls of the housing and provided with a -jcentlal'bore constituting the rotor chamber. A
' tubular standard it having a bottom flange I9 which constitutes the top plate of the rotor chamber-is seated upon the top of the annular member Withwthe tubular standard rising upwardly therefro'm Upon the flange I9 an annular spider 2l is supported which carries the stator 22 of the electric driving motor.
The standard yi8 serves as the journal bearing for both the rotor of the electric driving motor and the shaft of the pump so that the rotor and compressor or pump are coaxially disposed. A rdtor sleeve 23 carrying the rotor structure 24 surrounds and is journalled upon the periphery of standard I8. The compressor rotor shaft 26 is formed integrally with the pump and compressor rotor 21, and is journalled within standard I8 concentrically with sleeve 23. The upper portion of shaft 2B above standard I8 is squared to receive a driving disc 28 provided with radially projecting arms which engage in slots formed in the upper end of sleeve 23 whereby a direct but laterally adjustable driving connection between the rotor sleeve and the pump shaft is r accomplished.
The rotor of the pump and compressor is diS- posed eccentrically within the bore of the rotor housing and is provided with a plurality of' radially disposed blades 29 adapted to reciprocate radially in the rotor. The blades are maintained `surface of the shaft to lubricate the latter.
at all times-a predetermined distance apart by pin 3l extending transversely of the rotor between lthe blades. The length of the abutment pins is such that the outer ends of the blades which are provided with sealing members 32 will always be maintained in contact with the surrounding walls of the rotor housing. As one blade is forced inwardly during rotation of the rotorfthe corresponding blade will be forced through the rotor'and against the opposite wall.
The gas to be compressed by the pump is admitted in the usual manner to the cylindrical bore around the rotor before being connected thereto by suction pipe l2. The admitted gas is compressed by the rotation of the blades and discharged through an outlet port, not shown, and finally discharged into the interior of the sealed casing.
For lubricating and cooling the motor and compressor unit, I have provided a continuous lubricant circulation system in which the lubricant serves for lubricating the compressor and also sealing the same, as well as to cool the stator and/or rotor of the driving motor.
It is understood, of course, that a sufficient amount of oil is placed in the unit and settles to the sump from which it is piped by conduit 33 into an oil cooler orradiator 3d from which it is piped by conduit 35 to the well l5 through a duct 31 formed in the base. Oil will be sucked into the pump through a duct 3S extending from well l5 and leading to the space between the inner ,ends of the blades and the outer periphery of the pump rotor, the latter constituting the inlet for the oil pump which, in the present instance, is the compressor, the inner ends of the blades being used for circulating the oil and the outer ends being used for compressing the refrigerant.
The oil is discharge-d under pressure from the pumpv partly through an oil port 39 communicating with a central bore fil formed in the lower end of shaft 3G, which bore communicates with a spiral oil groove ft2 formed in the periphrlal e upper end of spiral groove Q2 communicates with a central bore 43 formed in the upper end of shaft 26 communicating with lateral ports dit which direct the oil outwardly upon a separating and distributing disc i6 which separates what refrigerant vmight be included in the oil and throws the oil outwardly between an outer cap or shield (il and an inner cap or shield 48 which directs the oil over the peripheral margin of stator 22.
Another portion of the oil discharged by the pump passes upwardly through a duct 59 which communicates with an annular groove 5l formed in the outer peripheral surface of standard I8 and which communicates with a spiral groove 52 which terminates at its upper end in a lateral duct 53 which directs the oil outwardly beneath a cap or shield 54 carried by the upper face of the motor rotor and which directs the oil downwardly through vertical apertures 56 formed in the rotor.
The stator is provided with vertical apertures 51 through which the oil passing between caps 4l and i8 is directed.` The periphery of the stator may also be serrated or grooved as at 58 to provide additional channels for conducting oil in intimate contact with the stator whereby greater cooling veffect is obtained. The latter are particularly effective when the quantity of oil passing between caps 41 and 48 is too great to be conducted by apertures 51, which are quite small, and flows over the peripheral rim of cap 1&8. The latter condition is also likely to occur when the oil is quite cool and consequently fairly thick.
The oil owing through apertures 56 and 51 collects in the bottom of spider 2l and passes out through a port 59 formed therein. The oil passing over the outer periphery of the stator and through`channels 58 is collected by an annular inclined trough 6l surrounding the spider and having its two ends terminating adjacent port 59.
To maintain the lubricating oil at a sufficiently high temperature to prevent absorption of refrigerant therein, the circulation of the oil through the cooling' radiator 313 is controlled. For this purpose duct 31 is provided with a pair of side outlets 52 communicating with the oil sump in the casing. These ports are controlled by a thermostatic valve shown more particularly in Figs. 3, 4 and 5, and comprising a valve body 63 secured over ports 62 having an interior chamber closed by a cap E4. The body is provided with a pair of side outlets or ports S8 communicating with the sump in the casing, the ports being disposed below the normal oil level in the casing.
The ports are arranged to be sealed by a bimetallic closure member 6l in the form of a ring secured at its mid point to a fixed abutment. 68 and having its end portions free to expand when the ring is heated to alpredetermined temperature to seal ports "66. The thermostatic valve is disposed below port 59 and the ends of trough 6l so that the warm oil delivered over and through the stator and rotor of the electric motor will be delivered upon the thermostatic valve. The screen 69 (Fig. l) is secured to and surrounds the thermostatic valve to strain the oil prior to its entering into the valve and thus prevents any foreign matter from affecting the operation of the valve. y
In operation the valve functions to permit warm oil to be circulated from the sump through the pump and over the motor, that is, when the oil in the casing reaches a temperature suiciently low so that there is danger of refrigerant being absorbed therein, the oil is by-passed directly.
from the motor through the thermostat valve to the suction side of the pump. When the oil reaches a temperature sufciently high so that there is no danger of refrigerant being absorbed in detrimental amounts, valve 6l closes ports 66 and the oil is circulated through the oil cooler Sli.
`It will be apparent that when valve 61 is open Av separate inlet port 'Hl and duct 'Il (Figs. 2lv
and 5) is provided to permit warm oil being utilized for seal oil at all times, which oil comes in direct contact with the gas in the compression chamber of the compressor. To assist in maintaining constant temperature and completely insulating the motor compressor unit both as to heat and noise, the unit is provided with an insulating cap 'l2 for the dome d? and an insulating cover 'I3 for the base. The` unit standsupon three arcuate feet 14.
From the foregoing description it will be apparent that I have not only provided for circulation of the lubricating oil in a manner which insures intimate contact oithe oil in heat-absorbing relation to both the stator and rotor but have also provided means for controlling or regulating the circulation of oil through the unit and oil cooler in such a manner as to assure a substantially constant temperature in the unit to prevent absorption of the refrigerant in the lubricating oil. Other novel features and their resultant advantages will be apparent to those skilled in the art, and to whom it will also be obvious that changes may be made in the details of construction without departing from the spirit and scope of this invention.
1. An apparatus comprising a casing, a pump within said casing, an electricrmotor within said casing, a driving connection between said motor and pump, means for delivering oilthrough certain of said pump and motor bearings and into heat absorbing contact With the stator of said motor, and means for delivering oil through other of the pump and motor bearings and into heat absorbing contact with the rotor of said motor.
2. An apparatus comprising a casing, a pump,4
within said casing, an electric motor within said casing, a driving connection between said Lmotor and pump, means for delivering oil through cer- -tain of said pump and motor bearings and into heat absorbing contact with the stator of said motor, means for delivering oil through other of the pump and motor bearings and into heat absorbing contact with the rotor of said motor, means for cooling all of the oil passing over said motor, and thermostatically controlled means'f'or regulating the cooling of said oil.
4. An apparatus comprising a base, an electric motor, a pump, a driving connection between said motor and pump, an oil distributor above said motor, means for delivering oil from said pump to said distributor whereby the same is distributed over said motor, a shield disposed in proximity to but spaced from said distributor for directing the distributed oil into contact with the motor stator, a case associated with said base to provide a sealed enclosure within which said pump, motor, distributor andshield are disposed, means for dissipating heat removed by said oil from the motor, thermostatically controlled means v for regulating'the dissipation of heat from said oil, and a collector associated with said stator arranged to collect the oil distributed into contactwith said motor stator and direct it over said thermostatic control. v
5. An apparatus comprising a base, an electric motor, a pump, a driving connection between said motor and pump, an cil distributor, means for delivering oil to said distributor whereby the same is distributed into contact with the motor stator,
said stator being provided with passages through the interior to permit flow of the oil therethrough, a ca associated with said base to provide a sealed enclosure within which said pump, motor and distributor are disposed, means for dissipating heat removed by said oil from the stator, thermostatically controlled means for regulating the dissipation of heat from said oil, and
l a collector associated with said stator arranged to collect the oil distributed into contact withsaid motor so that it may return by gravity in intimate heat absorbing relation with the motor and back into the lower portion of said case, and means for collecting the portion of the distributed fluid and directing it into contact with said therniostatic control.
7. An apparatus comprising a hermetically sealed casing adapted to contain lubricant, a pump and an electric motor disposed within said casing, means for directing lubricant from the pump into heat absorbing contact with the motor to absorb excess heat units therefrom, a lubricantt cooling device exteriorly of the casing, a connection through which lubricant is delivered from the lower part of the casing to said device, a connection through `which the cooled lubricant is delivered from said device back to the pump, a thermostatically controlled by-pass valve through which lubricant may be delivered directly from the casing to the pump, and means for collecting lubricant heated by the motor and directing the same against said valve whereby the opening and closing of the valve is controlled by the temperature of said' collected lubricant to vary the amount of lubricant circulated through perature of the apparatus.
8. An apparatus comprising a sealed casing providing a lubricant sump, a pump and a driving motor therefor located within the casing, means for directing lubricant delivered by the pumpinto heat absorbing contact With the motor to cause the absorption of excess heat units from the motor by said lubricant, means comprising a closed lubricant circuit including a cooling device for cooling the lubricant whichis withdrawn through said circuit from the sump and returned to said pump, a thermostatically controlled bypass v alve adapted to establish direct communication between said sump and the suction side of said pump, and means for collecting the lubricant heated by said motor and directing the same into thermal relation with said lthermostatic valveto thereby regulate the circulation of lubricant through said cooling device.
9. An apparatus comprising a casing providing an o'il sump, a pump and an electric motor within the casing, a driving connection between the motr and pump, means for directing oil delivered by the pump into heat absorbing contact with the motor to cool the vmotor, a cooler for removing from the oil the excess heat units absorbed from the motor, a conduit connecting the sumpto the inlet of the cooler, a conduit connecting the'outlet of the cooler with the suction side said cooling device and thereby regulate the temof the pump, said suction conduit being provided with apart opening into the sump, and thermostatically controlled means associated with said port for permitting a direct flow of oil from said sump to the suction side of said pump when the temperature of said oil is below a predetermined minimum, said pump being connected to circulate oil through said cooler when said thermostatic means is closed.
10. An apparatus comprising a casing, a pump and an electric motor disposed therein, an oil cooler, a pipe for conducting oil from the casing to the cooler, a pipe for conducting cooled oil from said cooler to the pump, a port for establishing communication between said casing and the pump intake through Which oil may be delivered directly from the casing to the pump and a thermostatic valve controlling said port, said valve being influenced by the temperature of the oil ,in said casing to permit direct iioW of oil from the casing to the pump under low temperatures and to prevent such direct flow and cause flow through said cooler under high temperatures, whereby the temperature of the oil delivered by the pump is regulated, and means for directing said oil into heat absorbing Contact with said motor to cool the same.
11. In a refrigerating apparatus, the combination of a casing member providing a lubricant sump in the lower portion thereof, an electric motor including a stator member and a rotor member mounted within said casing, a vertically disposed shaft supporting said rotor member, a lubricant circulating pump driven by said shaft and having inlet and outlet ports, means for dividing the lubricant under pump pressure into a. plurality of streams, means for conducting all of the lubricant discharged by the pump to an elevation above said motor from which elevation both of said streams are separately returned under the influence of gravity to said sump, means for directing the lubricant of one of said returning streams into heat transferring relation with one of said members, independent means for directing the lubricant of the other of said returning streams into heat transferring relation with another of said members, and means whereby heat units transferred from the motor to said lubricant may be delivered from the casing.
CARL E. L. LIPMAN.