US2781632A - Device for circulating a medium in a reciprocating engine - Google Patents

Description

Feb. 19, 1957 2,781,632

R. J. MEIJER DEVICE FOR CIRCULATING A MEDIUM IN A RECIPROCATING ENGINE Filed Sept. 6, 1950 6a INVENTOR.

Roeh Jam Mei er %W% AGENT United States DEVICE FOR CIRCULATING A MEDIUM IN A RECIPROCATING ENGINE Application September 6, 1950, Serial No. 183,441

Claims priority, application Netherlands September 21, 1949 8 Claims. (Cl. 60-24 This invention relates generally to devices comprising a vessel containing a medium subject to variations in pressure. More particularly, the invention relates to means for employing such variations in pressure to per form additional useful functions.

As an example of such devices which normally have pressure variations, the closed crank case of certain types of motors with internal or external combustion may be noted. In such a crank case, which in this case constitutes the vessel, variations in pressure periodically occur due to the reciprocating movement of the piston or pistons in the cylinders connected to the crank case. A further example of such a vessel is the cylinder space of a reciprocating engine, in which variations in pressure also occur periodically.

The present invention is directed to the finding that it is possible to take advantage of such pressure variations which, for other reasons, already occur in a closed vessel; and so fulfil, for example, one or more auxiliary functions. This is accomplished with the use of a circulation device with which 'the' vessel is provided for just this purpose.

The device according to the invention is characterized in that provision is made of a circulation device having the two ends thereof opening into the vessel of such a device, while a flow of medium occurs at least substantially in one direction. The last is due to the presence of suitable means and to the aforesaid pressure varia tions which occur in the vessel. The said medium performs useful work, such as the additional functions mentioned above, as a result of this flow.

In one embodiment of the invention, the medium fiowing through the circulation device serves as a transporting means for another medium. According to the invention, the medium flowing through the circulation" device and serving as a transporting means may be in the gaseous form and the other medium which is to be transported may be liquid in a finely divided state, such, for example, as a lubricant.

It is furthermore possible that the medium flowing through the circulation device performs useful work on account of its nature, it being possible to utilize the 2 advantage in hot-gas reciprocating engines. Here the term hot-gas reciprocating engine is to be understood to mean either a hot-gas engine or a refrigerator operating according to the reversed hot-gas reciprocating engine principle. As is well-known, the power output of hot-gas reciprocating engines islhighly dependent upon the amount of medium taking part in the cycle of the engine. Since, as a rule, acertain leak of medium will occur during the operationof the engine, the power supplied by the engine or the amount of cold produced by the refrigerator will decrease. It is thus desirable that the amount of working medium should be replenished. It is possible to utilise the gas contained in the crankcase for replenishment of the working medium. However, as a rule, this gas will be contaminated by lubricant. This lubricant should be removed from the gas, since it is detrimental to the operation of the engine if the lubricant finds its way into the working space of the engine. That is, the lubricant might then be cartied off by the working medium from the working space to theheat exchangers or the regenerator to diminish the efiiciencies thereof. This naturally will result in a deterior periphery thereof directed crease in power output of the engine. 7

Furthermore, in order to avoid excessive consumption of lubricant, it is desirable, that the lubricant separated from the gas should be fed back to the crankcase. In order to ensure such desirable replenishment of the crankcase supply, according to one embodiment of the invention, a reciprocating engine constructed as a hotgas reciprocating engine and comprising a device of the kind above described, is characterized in that the circu lation device includes aseparator by which the lubricant contained in the finely divided state in the gaseous medium is separated from the gaseous medium. .Means are further provided for ensuring that this lubricant is mixed again with part of the gaseous medium and then fed back by such a gaseous medium through the circulation device to the crankcase. On the other hand, the medium carried away from said separator free of lubri-' cant is supplied to one or more cycles of the hot-gas reciprocating engine. A

"The device according to the invention may also be applied to advantage in a horizontally disposed reciprocating engine in which a certain portion of the surface of the piston is required to be kept free from excess lubricant. This reciprocating engine is characterized in that at least one substantiallycircumferential slot is provided in the piston. The said slot opens out in the side surfaces of the piston and extends substantially transversely to the direction of movement thereof but with the intowards that part of the surface of the piston which must be kept free from excess lubricant. The latter part of the surface is lo- I cated at a greater distance from the wall of the cylinder physical and/or chemical properties of the circulating ing or. a lubricating agent. I

'In another embodiment of the invention, themedium flowing through the circulation device may be liquid, and an air chamber may be provided in the circulation device between the elements of the means which per- ;mit a flow at least substantially in one direction in said device.

In order to vary the amount of useful work performed by the circulating medium, in one advantageous embodiment of the invention, the circulation device includes an arrangement for controlling the amount of medium flowing through it.

The device according to the invention may be used to medium so that thelatter serves, for example, as a coolthan the partofthe surface on which excess lubricant may be present. Furthermore, on the lower side of the running surface of the horizontally disposed piston, the slot communicates through a circulation device with the space located between the last-mentioned part of the surface of the piston and the wall of the cylinder.

The function of the above-mentioned slot is to reduce the amount of lubricant which is transported to theworking space of the engine due to the reciprocating movement of the piston. If the piston is not positioned exactly vertically, but is positioned at anangle or horizontally as noted hereinbefore, it is possible that an amount of lubricant will be collected on the lower side'of thepiston, to, such an extent that the slot cannot properly fulfil its function as a check for the lubricant. Consequently, it is desirable that the lubricant present on the lower side of the piston should be transported again to the upper.

side of the piston. For this purpose use may be made of V Patented Feb. 19,1957

the device according to the invention. In this embodiment the working space, which is influenced by the piston, serves as the vessel containing a medium subject to variations in pressure.

In a further embodiment of the invention, a reciproeating engine comprises a device in which the crank case serves as the vessel and lubricant flows through the cir culation device, this lubricant upon leaving the circulation device being used for lubrication of moving parts of the engine. In this case, the medium flowing through the circulation device performs useful work on account of its nature. Such an embodiment may also be used to advantage if the circulation device is traversed by a cooling agent which is used for cooling certain parts of the engine.

The invention will now be explained more fully by reference to the accompanying drawing, wherein:

Fig. 1 is a diagrammatic vertical cross-sectional representation of one embodiment of the invention applied to a reciprocating engine wherein lubricant is atomised with the use of the circulation medium.

Fig. 2 is a. diagrammatic vertical cross-sectional representation of another embodiment of the invention applied to a hot-gas reciprocating engine in which the working medium which is replenished is comprised of the medium freed from lubricant. The crank case serves as the vessel in which the medium is subject to variations in pressure.

Fig. 3 is a diagrammatic vertical cross-sectional representation of another embodiment of the invention applied to a horizontally disposed piston shown in part section in order to illustrate the slot arrangement therein for reducing the amounts of lubricant taken along by the piston.

Fig. 4 is a diagrammatic vertical cross-sectional representation of still another embodiment of the invention applied to a reciprocating engine comprising the device by which lubricant is circulated in accordance therewith.

In Fig. 1, reference numeral 1 indicates the crank case of a reciprocating engine. The crank case serves as a vessel containing medium subject to variations in pressure. The variations in pressure occur due to the reciprocating movement of the piston 3 in the cylinder 2. The piston 3 is connected to the crankshaft 5 by means of a driving rod 4.

The crank case comprises a circulation device which in turn comprises a channel 6, non-return valve 7 in said channel 6, a chamber 8, a channel 9, a non-return valve in said channel! and an atomiser 11 all preferably connected in a manner similar to that illustrated. Owing to the presence of the non-return valves 7 and 10, the movement of the piston 3 in the cylinder 2 produces in the chamber 8 a pressure lying between the upper and lower limiting pressures periodically occurring in the crank case 1. If the'pressure in the crank case is higher than the pressure in the chamber '8, an amount of air flows from the crank case 1 by way of the non-return valve 7 and the conduit .6 to the chamber 8. When the varying pressure in'the crank case 1 decreases, the pressure in the chamber 8 at that given moment exceeds the pressure in the crank case, so that the air from the chamber 8 flows through the conduit 9, the non-return valve 10 and the atomiser 11 back to the crank case 1. 'A container 12 is provided below the level of the crank case 1 and is connected thereto by'means of a conduit 13. 'T he container 12 is adapted to contain a quantity of lubricant 14 and has connected thereto, below the normal level of said lubricant 14, a conduit 15 which at its other end 16 opens out into the atomiser 11. Thus when air flows through the atomiser as described hereinbefor'e, lubricant is sucked from the container 12 by the said air and atomised, theair thus performing useful work. The atomiser 11 is so directed and positioned that the pivots in the crank case, 1, i. e. the driving rod 4, crank shaft 5 connections which are to be lubricanted, are in the path of the air-lubricant mixture ejected from said atomiser 11. The

excess lubricant flows from the crank case 1 back into the container 12 via conduit 13. If desired, the flowback conduit 13 may include a filter (not shown) so that the circulating lubricant 12 is purified. It is evident that the device according to the invention may fulfil its function in a similar manner if the conduits 6 and 9, instead of including the non-return valves 7 and 10, comprise, for example, throttle plates having different resist anccs in one direction of flow.

The hot-gas reciprocating engine shown in Fig. 2 is constructed according to the displacer type. Here a displacer 21 and a piston 22 reciprocate in a cylinder 20, the displacer 21 and the piston 22 each being connected by means of a conventional driving-rod mechanism 34 to the crank shaft 35 whereby the usual out-of-phase relationship between the reciprocating of said displacer 21 and piston 22, necessary to hot-gas piston engine operation, is obtained. The part of the working space 36 above the displacer 21 is, as normally, the hot space, and communicates by way of the usual heater 23, regenerator 24 and cooler 25, with the working space 37 between the piston and the displacer. The last-mentioned portion of the working space is the usual cold space. Periodic variations in pressure occur in the crank case 26 due to the reciprocating movement of the piston 22. The crank case 26 serves as a vessel containing a medium which is subject to variations in pressure. During the high-pressure period, an amount of air which contains lubricant in the finely-divided state due to the agitation of a pool thereof in the crank case 26, is caused to flow therefrom via a conduit 27 provided for that purpose. The air lubricant mixture expelled from the crank case via said conduit 27 flows into a circulation device now to be described. This circulation device comprises in addition to said conduit 27 which may be considered a part thereof, a non-return valve 2'3, a separator 29 of the conventional structure, and a conduit 31! including a control device 31 preferably connected in the mannershown. The amount of fluid mixture comprisingair and lubricant which is driven into the circulation device during the high-pressure period is freed from lubricant in the separator 29, whereafter part of the air is mixed again with the lubricant and flows through the conduit 30 back to the crank case 26 during the low-pressure period therein. This air thus performs the useful work of replenishing the lubricant supply. The amount of lubricant which accomplishes this cycle is controllable bythe use of the regulating cock 31. An amount of air freedfrom lubricant is separately carried away from the separator, 29, by means of a conduit 32 which includes a nomreturn valve 33 therein, to replenish the working medium in the hot-gas reciprocating engine.

Fig. 3 shows a reciprocating engine comprising a piston 41 moving in the horizontal direction in a cylinder 42. As a rule, it is desirable that in reciprocating engines no lubricant or substantially no lubricant. should find its way into the working space. However, since the present piston 41 is one that mustbe lubricated, it is possible that the lubricant used for such lubrication may be introduced into the Working space 44 due to the reciprocating movement of the piston 41. In order to avoid this, the piston 41, which reciprocates in the cylinder 42, comprises a slot: 43 extending substantiallytransversely of the direction of movement of the piston 41 A portion 45 of the surface of the piston 41' adjacent working space 44 is required to be kept free of excess lubricant. This portion 45 is located at a greater distance from 'the wall of the cylinder 42 than that portion of the piston surface 46 on which excess lubricant may be present. As may be seen in Figure 3, the slot 43 has the interior periphery thereof direc ted towards the portion 45 which is .to be .kept free from excess lubricant. Due to the presence of the slot 43, the lubricant, transp'ortedtowards the working space 44 because of the reciprocating movement of the piston 41 so that the action of the slot 43 may be rendered less efl ec'tive. in order to remove this excess quantity of lubricant, in accordance with the present invention, the piston 41 comprises a channel system of which one extremity opens out on the lower side of the piston 41 into the slot 43, preferably into the bottom thereof. The other extremity of the channel system opens out on that portion of the wall of the cylinder on which excess lubricant may be present without such detrimental results as working space contamination. it is advantageous that the channel system opens out on the upper side of the piston 41 and in a region 46 between the slot 43 and the first of the piston rings 47.

The working space 44 in the cylinder 42 now serves as a vessel in which the working medium is subject to variations in pressure. This vessel comprises a circulation device comprising a slit-like space 53 defined between the portion 45 of the surface of the piston 41 and the wall of the cylinder 42, the slot 43, a channel 48, which includes a non-return valve 49, a chamber 50, a channel 51, including a non-return valve 52, a second slit-like space 54- between the portion 46 of the surface of the piston 41 on which excess lubricant may be present and the wall of the cylinder 42, and the slot 43. Due to the presence of the non-return valves 49 and 52, a pressure occurs in the chamber 50, the amount of said pressure being at a value between the upper and lower limiting pressures occurring in the working space 44. During the high-pressure periods in the working space 44, an amount of working medium flows through the channel 48 to the chamber 50. This working medium serves as transport means for the excess lubricant which might be present in the slot 43. During the low-pressure periods in the working space 44 and hence when the pressure in the chamber 50 is higher than in this space, the mixture of liquid and gas flows through the channel 51 and past valve 52 to the slit-like space 54 between the portion 46 of the surface of the piston 41 and the wall of the cylinder 42. The mixture of air and lubricant is blown against the wall of the cylinder 42 with the result that the lubricant is separated from the air. The air flows back tot'he working space 44 while the transportation of lubricant to the working space 44 is reduced due to the presence ofthe slot 43 which traps any lubricant moving toward said working space 44. The working medium is prevented from leaking past the piston 41 and in the direction opposite that of the working space 44 by the presence of the piston rings 47.

The device described immediately hereinbefore is also applicable if the cylinder is not positioned horizontally, but is positioned, for example, at an angle.

In Fig. 4, solely liquid instead of gas is circulated by the pumping arrangement provided as described hereinafter. The crank case 61, which serves as a vessel in which the medium is subject to variations in pressure, is partly filled with lubricant 72. The pressure variations in the crank case 61 arise due to the reciprocating movement of a piston 62 in a cylinder 63. The piston 62 is coupled to a crank shaft 65 by means of a piston rod 64.

The crank case comprises a circulation device in which medium flows at least substantially in one direction due to the presence of suitable means and to the variations in pressure occurring therein. The said circulation device comprises a channel 66, including a non-return valve 67, an air chamber 68, and a channel 69 which comprises not only a regulating device 70 but also a non-return valve 71. The crank case 61 is partly filled with lubricant 72 as indicated hereinbefore. One extremity of the circulation device connects into the crank case below the level of the lubricant 72 therein. Due to the presence of the non-return valves 67 and 71, a pressure occurs in the air chamber 68 which has a value between the upper and lower limits of the pressures occurring in the crank-shaft case. During the high-pressure periods, an amount of lubricant is expelled from the crank case 61 whereas during the low-pressure periods an amount of lubricant is pose, the channel 70 opens above the crank-shaft 65 at 73.

What, I claim is:

1. A reciprocating device comprising a cylinder, a piston and a working medium in said cylinder, a crankcase adapted to contain a fluid medium, means operatively associated with said crankcase for subjecting fluid medium contained therein to variations in pressure, and a circulation device; said circulation device comprising a pair of conduits each communicating at one end thereof with the other, and at the other end thereof with said crankcase, a valve in each of said pair of conduits for permitting flow of medium through said circulation device in substantially only one direction, separator means connecting said conduits together at said one end of each and for separating gaseous and liquid components of said fluid medium; and means for conducting the separated gaseous component separately from said separator means to said crankcase and to said cylinder and working medium respectively.

2. A reciprocating device comprising a cylinder, a piston and a working medium in said cylinder, a crankcase adapted to contain a fluid medium, means operatively as sociated with said crankcase for subjecting fluid medium contained therein to variations in pressure, and a circulation device; said circulation device comprising a pair of conduits each communicating at one end thereof with the other and at the other end thereof with said crankcase, mean for permitting flow of medium through said circulation device in substantially only one direction, means for regulating the amount of said flow; separator means connecting said conduits together at said one end of each and for separating gaseous and liquid components of said fluid medium; and means for conducting the separated gaseous component separately from said separator means to said crankcase and to said cylinder and working medium respectively.

3. A reciprocating engine comprising a crankcase adapted to contain a fluid meditun, cylinder means opening out into said crank case, piston means in said cylinder means and operatively associated with said crank case for subjecting fluid medium contained therein to variations in pressure, and a circulation device; said circulation device comprising a pair of conduits each communicating at one end thereof with the other and at the other end thereof with said crank case, means for permitting flow of medium through said circulationdevice in substantially only one direction, one of said conduits comprising atomizing means at said one end thereof, and conduit means connecting the bottom of said crank case into said atomizing means.

4. A reciprocating device comprising a crank case adapted to contain a fluid medium, cylinder means opening out into said crank case, piston means in said cylinder means and operatively associated with said crank case for subjecting fluid medium contained therein to variation in pressure, and a circulation device; said circulation device comprising a pair of conduits each communicating at one end thereof with the other and at the other end thereof with said crank case, a valve in each of said pair of conduits for permitting flow of medium through said circulation device in substantially only one direction, and separator means connecting said conduits together at said one end of each and for separatinggaseous and liquid components of said fluid medium; and means for conducting said separated gaseous component separately from said separator means and into said cylinder means.

5. A reciprocating device comprising a cylinder defining in part a pressure chamber and arranged at an angle to the vertical, a piston in said cylinder having a surface thereof variably delimiting said chamber, a slot in said piston adjacent the region of said chamber and extending substantially transversely of the direction of movemerit of said piston and opening out on the circumferential surface thereof, said slot having the interior periphery thereof directed towards said chamber, said circumfen ential surface of said piston in the area defined between said opening out of said slot and said chamber delimiting surface being spaced from the wall of said cylinder a greater distance than is the remainder of said circumferent-ial surface, and a circulation device located in said piston; said circulation device comprising conduit means said conduitmeans opening out at one end thereof into said slot in the region of the lower side of said circumferential surface of said piston occasioned by said angled arrangement, and at another end thereof into the space defined between a portion of said remainder of said circumferential surface and said wall of cylinder in the region of the, higher side of said circumferential surface.

6. A reciprocating device comprising a cylinder defining in part a pressure chamber and arranged at an angle to the vertical, a piston in said cylinder having a surface thereof variably delimiting said chamber, a slot in said piston adjacent the region of said chamber and extending substantially transversely of the direction of movement of said piston and opening out on the circumferential surface thereof, said slot having the interior periphery thereof directed towards said chamber, said circumferential surface of said piston in the area defined between said opening out of said slot and said chamber delimiting surface being spaced from the wall of said cylinder a greater distance than is the remainder of said circumferential surface, and a circulation device located in said piston; said circulation device comprising conduit means, said conduit means opening out at one end thereof into said interior periphery of said slot in the region of the lower side of said circumferential surface of said piston occasioned by said angled arrangement, and at another end thereof into the space defined between a portion of said remainder of said circumferential surface and said wall of cylinder in the region of the higher side of said circumferential surface.

7. A reciprocating device comprising a cylinder defining in part a pressure chamber and arranged at an angle to the vertical, a piston in said cylinder having a surface thereof variably delimiting said chamber, a slot in said piston adjacent the region of said chamber and extending substantially transversely of the direction of movement of said piston and opening out on the circumferential surface thereof, said slot having the interior periphery thereof directed towards said chamber, said ci1'cum-.

ferential surface of said piston. in the area defined between said opening out of said slot and said chamber delimiting surface being spaced from the wall of said cylinder a greater distance than is the remainder of said circumferential surface, a piston ring mounted on said piston in the region of said remainder of said circumferential surface, and a circulation device located in said piston; said circulation device comprising conduit means, said conduit means opening out at one end thereof into said slot in the region of the lower side of said circumferential surface of said piston occasioned by said angled arrangement, and at another end thereof into the space defined between a portion of said remainder of said circumferential surface above said piston ring and said wall of cylinder in the region of the higher Side of said circumferential surface.

8. A device comprising a vessel adapted to contain a fluid medium, said vessel also containing lubricating oil intermingled with said fluid medium, means operatively associated with said vessel for subjecting fluid medium contained therein to variations in pressure, and a circulation device, said circulation device comprising a pair of conduits, the first of said conduits having one end communicating with said vessel, the second of said conduits also having one end communicating with said vessel, the other end of each of said first and second conduits communicating with each other, means in each of said conduits for permitting flow of said medium in said conduits in one direction only, an air chamber interposed between the other ends of said conduits, and means for blowing a mixture of said fluid medium and said lubricating oil from said second conduit into said vessel upon a predetermined pressure differential between said second conduit and said vessel.

References Cited in the tile of this patent UNITED STATES PATENTS 904,132 Johnston Nov. 17, 1908 1,385,250 Gernandt July 19, 1921 1,441,329 Cato Jan. 9, 1923 1,796,792 Johnson Mar. 7, 1931 2,011,964 Ajam Aug. 20, 1935 2,066,489 Shannon Jan. 5, 1937 2,073,886 Stifter Mar. 16, 1937 2,233,168 Johnson Feb, 25, 1941 2,513,547 Buell et al. July 4, 1950

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