US2301656A - Compression refrigerating machine with oil collecting space in the crankcase - Google Patents

Description

W. HIRCHE Nov. 10, 1942.

COMPRESSION REFRIGERATING MACHINE WITH OIL COLLECTING SPACE IN THE CRANK CASE Filed Aug. 29, 1939 Patented Nov. 10, 1942 COMPRESSION REFRIGERATING MACHINE WITH OIL COLLECTING SPACE IN THE CRANKCASE Willy Hirche, Leopoldshain, Gorlitz-Land, Germany; vested in the Alien Property Custodian Application August 29, 1939, Serial No. 292,383 In Germany September 1, 1938 4 Claims. (Cl. 62115) The invention relates to a compression refrigerating machine, in which the crank case is constructed to provide an oil collector with the crank case shut off on all sides. In such machines it is unavoidable, that traces of oil escape from the crankcase between piston and cylinder wall and that, on the other hand, refrigerant vapours get from the stroke space of the cylinder into the crank case. Both these occurrences are detrimental to the operation of the machine. Travelling oil particles reduce the oil quantity in the crank case and deposit it at other points of the plant thereby reducing its efiiciency. Refrigerant vapour which has leaked into the crank case increases the pressure in the crank case, renders diflicult the running of the engine, finally condenses and impairs the lubricating capability of theoil.

According to the invention the foregoing inconveniences are obviated in that arrangements are provided, which return to the proper place the refrigerant vapour which has penetrated into the crank case and the lubricant which has been removed from the crank case.

The drawing illustrates two embodiments of;

the invention.

Fig. 1 shows in vertical section one embodiment, and

Fig. 2 the second one.

The crank case designated by I merges at its top into the cylinder 2,- whereas the motor casing 3 is connected with one of its sides. The crank case is air-tightly closed at all sides by the motor casing 3 and by the cylinder head 4. The crank shaft 5, carrying the rotor 5 of the driving engine, is journalled at l and 8 in the crank case. The piston 9 is reciprocated in the cylinder 2 by the crank II and the connecting rod l0, The-shaft B carries at the end opposite the rotor a cylindrical slide valve l2 which tightly fits in the lateral extension [3. The refrigerant vapour is conducted by the evaporator l4 through pipe into the upper portion of a closed container IS, in which it strikes against a partition [1, on which the oil particles separate which have been drawn along, whereupon the refrigerant vapour flows through a pipe l8 into the suction chamber IQ of the cylinder head 4, through the valve into the stroke chamber of the cylinder, then through the valve 2| into the pressure chamber 22 and finally into the condenser 23 from which the condensed refrigerant, together with the oil particles drawn along, flow again through a pipe l8 into the suction cham- 20 into the stroke chamber of the cylinder, then through the valve 2| into the pressure chamber 22 and finally into the condenser 23, from which the condensed refrigerant. together with the oil particles which have been drawn along fiow again through an expansion device 24 back into the evaporator.

The lower portion of the crank case serves as oil collector. In this lower portion a pump 25 or any other distributor element is arranged, to lead the lubricant to the lubricating points. On the head of the connecting rod a scoop may be arranged which dips into the collected oil and throws the oil about in the crank case. The oil also moistens the running surface of the cylin- .der and is wiped ofi by the piston. At this occasion traces of oil get over the piston into the stroke chamber of the cylinder, are drawn along by. the refrigerant vapours and get into the separator l6 together with the refrigerant through the condenser and evaporator. In the separator the oil collects on the bottom and flows into a pipe 26 connected to the casing l3. Opposite the mouth of the pipe 26 the rotary slide valve I2 has a pocket-like indentation 21 in its circumference, which indentation fills with oil if it is opposite the mouth of pipe 26. During the rotation of the slide valve 12 the indentation or pocket 21 comes opposite a pipe 28 extending from the crank case, so that the oil from the pocket 21 returns through the pipe 28 into the crank case.

The rotary slide valve does not admit of a direct communication of the container IS with the crank case, as one of the pipes 26, 28 is always shut ofi when the other communicates with the pocket 21, so that, for instance when the machine is tilted during transport, the content of the crank case cannot flow into other parts of the plant. On the other hand the oil is periodically returned from the container l6 .into the crank case during the operation of the engine.

During the pressure stroke of the piston refrigerant vapours can get between piston and cylinder wall into the crank .case.- For returning these vapours a pipe 29 extends from the upper portion of the crank case, i. e; the steam chamber, and terminates in the casing I3 opposite an indentation or pocket 3!] in the rotary slide valve. A pipe 3| terminating in the suction pipe l5 branches from the casing l3 opposite the line along which the indentation or pocket 30 rotates. If the pressure in the crank case has increased by vapours which have penetrated into her IQ of the cylinder head 4, through the valve the case, a periodic pressure equalization is efiectgem;

fected by pumps or other conveyingelements of suitable construction.

In the form of construction shown in Figl i the pressure equalisation is effected in another manner. In this instance apocket 3.2 op n to der and crank case closed on all sides with an oil collecting space in the crank case, a gas and oil separator, conduits connecting the oil collecting space and the separator, and means in said conduits for controlling the return of oil from the separator to the oil collecting space and the return of gas to the separator including a cylinder interposed in at least one of said conduits, a plug rotatable in said cylinder and having a surface indentation adapted during rotation of the plug ,to receive-soil from the separator for return to @the'cranlg c aseandmeans in the other conduit to wards the cylinder wall is provided-in the lower" part of the piston wall, and arecess-tjtf-at. the

lower end of the cylinder in the side wall ofzthesame. A pipe 34 extending from the container [6 terminates in the cylinder at the height-"of idea may, however, be 'applied-alsoto refrigerating machines with rotary compressor; Theinvention is not limited to the pos'itionpf the compressor cylinder opp sitethecrank. casa'as this cylinder may be vertical, as shown the draw.- ing, but also hanging or horizontal. "I he idea is common to all forms of constructipn to return to heir prope pl rei s a tramu which, has got into the crank case closed on allsidesand oil which hasescaped from lthe'crank case, and to prevent collection of oil at any other point but in the crank casewhich forms the'only oil col-' lecting space. The invention is particularly ad} vantageous for refrigerating'plants with several evaporators.

I claim: a

1. A compression refrigeratingapparatus, comprising in combination witl a compressor cylinder and crank case closed on all sides with an oil collecting space in the crank case, a gas and oil separator, conduits connecting the oil collecting space and the separator; and means in Said conduits for controlling the return of Oilfrom the separator to the oil collecting space and theretum of gas to the separator including a cylinder interposed in the conduits, a plug. rotatable in said cylinder andv having surface indentations adapted during rotation ,of the plug respectively to receive gas and oil from the crankcaseand separator for return .of the gas to the separator and the return of the oil to the crank case.

2. A compression refrigerating apparatus, cornprising in combination with a compressor cylin- "control the return of gas from the crank case to the separator. I

v 3.11 compression refrigerating apparatus, comprising in combination with a compressor cylinder anda crank case closed on all sides with an oil collecting space in the crank case, a gas and oil separator, conduits connecting the oil collectingspace and the separator, and a controlled element adapted to effect a pressure equalization between the crank case and suction side of the machine and operative for controlling the return of oil from the separator to the oil collecting space and the return of gas to the separator, including an extension projecting from said crank case, a rotary slide valve. iri said extension and having pocket like indentations in its circumference, an oil return pipe extending from-said extension in therotary plane of one of said indentations and terminating in the crank case, and a-pressure compensatingpipe extending from the other of said pocket-like indentations in the rotary'plane of the other pf said indentationsand terminating thecrank case.

4. A compression refrigerating apparatus, comprising combination with a compressor cylinder and a crankcase closed on all 'sides with an oil collecting space inthe crank case, a. gas and oil para or u t n n liht l nwing "spec and ,the' separator, and a controlled element adapted toefie'ct apressuree'qualization between the cram case and suction side of the machine and'operative for controlling the return of oil from the separator to the oil collecting space and the return of gas to the separator, including an extension of said crank case, a rotary slide valve'in said extension and having a pocketlike indentation in its circumference, an oil. return pipe extending from said extension in the rotary plane of said indentation and terminating in said crank case, a piston in said cylinder having a pocket-like indentation open towards the crank case wall, a connecting pipe extending from said separator to said crank case wall to said 'pocket 'like findentation" in the piston, a pocket in said crankcase under said piston and open towards'the inner and lower sides through whichwhen'the piston is infthe lowermost 'position refrigerant gas can flow into said indentation, aconnecting pipe between the cylinder and the oil separator adapted to conduct gas of the refrigerating medium from said pocket into said separator.

. WILLY HIRCi-IE.

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