US3413963A - Apparatus for liquid cooling of pistons in piston-type internal combustion engines - Google Patents

Description

3 1963 cs. J. HELLINGMAN 3, 3,963

APPARATUS FOR LIQUID COOLING OF PISTONS IN PlSTONTYPE INTERNAL COMBUSTION ENGINES Filed March 16, 1967 3 Sheets-Sheet 1 I 8 "#w l l 12 E 13 5 i a k 17 5 x Inventor.-

GOSEN JOOP HELLINGMAN 42. J ZWMJ AMW ATTO RN EYS 1968 G. J. HELLINGMAN 3,413,963

APPARATUS FOR LIQUID COOLING OF PISTONS IN PISTON-TYPE INTERNAL CGMBUSTION ENGINES 5 Sheets-Sheet 2 Filed March 16, 1967 /n vent or:

GOSEN JOOP HELLINGMAN q, 25.5.5.5 as r BY W 'MJ MMGAW ATTORNEYS Dec. 3, 1968 3. J. HELLINGMAN 3,413,963

APPARATUS FOR LIQUID COOLING OF PISTONS IN PISTON-TYPE INTERNAL COMBUSTION ENGINES 5 Sheets-Sheet 3 Filed March 16, 1967 FI'Q'. 4

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GOSEN JOOP HELLINGMAN BY W MQJ ZW ATTQRINEYS United States Patent O 3,413,963 APPARATUS FOR LIQUID COOLING OF PISTONS [N PISTON-TYPE INTERNAL COMBUSTION EN- GINES Gosen .loop Hellingman, Zurich, Switzerland, assignor to Sulzer Brothers Limited, Winterthur, Switzerland, a Swiss company Filed Mar. 16, 1967, Ser. No. 623,745 Claims priority, application Switzerland, Mar. 18, 1966, 3,996/ 66 8 Claims. (Cl. 123-41.36)

ABSTRACT OF THE DISCLOSURE There is disclosed an internal combustion engine having a liquid-cooled piston or pistons. For each piston there are provided two pairs of tubes. One tube of each pair is fixed at one end to the piston and moves with it. The other tube of each pair is fixed at one end to a stationary part of the engine, and the free ends of the two tubes of each pair are in telescoping relation to each other, with the movable tube extending outside the stationary tube. A packing or sleeve is provided between the two tubes of each pair. Water or other coolant flows under pressure into one of these stationary tubes, into the movable tube in telescoping relation therewith, through a cavity in the piston, and back out through the other pair of tubes. The movable tubes extend moreover through packings into a chamber which is closed off from the engine crankcase, and the stationary tubes have their fixed ends within this chamber. Separate conduits connect the stationary tubes with coolant supply and return facilities outside the engine. An additional conduit permits withdrawal of coolant accumulating in this chamber, which is moreover connected, at the upper part thereof with the atmosphere outside the engine. The free end of one or both of the stationary tubes is shaped to act as an ejector with the aid of the coolant flowing through it. The suction space of the ejector thus provided is connected by a conduit or conduits with the annular sleeve-like space between the telescoped portions of the tubes in which this ejector is located. The ejector action occurring upon the flow of coolant thus acts to aspirate air and/or coolant which may find its way into this annular space. A storage space may be provided in communication with these conduits, within which coolant may accumulate between the intervals of intensive ejector action, which varies due to piston motion.

Field .0) the invention The present invention relates to liquid cooling of the pistons in piston-type internal combustion engines. and particularly to means for preventing loss or contamina tion (as by lubricating oil) of coolant employed for that purpose.

Description of the prior art It has already been proposed to cool an engine piston by means of two tubes fixed at one end to the piston and moving therewith, the tubes passing with their free ends through packings into a stationary chamber, and to pro- Vide a stationary tube fixed at one end in that chamber, with its free end extending in telescoping relation into one of the movable tubes and having moreover a nozzle at that free end through which a coolant such as water is forced under a pressure of some three to four atmospheres into the cooling space of the piston. The heated water passing out of the cooling space flows through the second movable tube into the chamber, from which it is transferred to a cooler or other heat dissipating device. In

such a construction difficulties may be experienced at the packings between the chamber and the remainder of the engine, where the movable tubes pass into the chamber. Thus water can leak out of the chamber along the tubes at these packings, into the space beneath the piston. This entails water losses which can be very disadvantageous in marine engines, where this will be fresh water. Moreover, there exists also the danger of contamination of the cooling water by residual products of combustion which may contain oil or other lubricants.

It has moreover already been proposed to dispose a second stationary tube, with its free end in telescoping relation with the movable tube which serves for withdrawal of the cooling water. This second stationary tube connects to a suitable exit line and carries off a large part of the flow of water so that only a small proportion thereof falls into the chamber. In this way, it is possible to reduce significantly the difiiculties above referred to. In particular, the packings between the chamber and the underside of the piston are subjected to much less severe operation.

Summary of the invention The invention provides a further improvement in this direction. By means thereof, the emergence of cooling liquid from the tubes into the chamber is still further reduced, with the particular advantage that there is excluded the possibility of contamination of the cooling water by oil and incompletely burned fuel seeping out of the combustion chamber above the piston.

In accordance with the invention, there is provided at the free end of one or both of the stationary tubes :1 nozzle shaped to act as an ejector with the aid of the coolant flowing through it. The suction space of the ejector thus provided is connected by a conduit or conduits with the annular sleeve-like space between the telescoped portions of the tubes in which this ejector is located. The ejector action occurring upon the flow of coolant thus acts to aspirate air and/ or coolant which may find its way into this annular space. A storage space may be provided in communication with these conduits, within which coolant may accumulate between the intervals of intensive ejector action, which varies due to piston motion. A ring or packing may also be provided below the portion of the sleeve- -like space to which the conduits connect. and this packing may be given a desired clearance from the other of the two telescoping tubes, so as to control the aspiration of air at the ejector.

Brief description. 0 the drawing The invention will now be further described with reference to the accompanying drawings, in which:

FIG. 1 is a fragmentary transverse sectional view of a diesel or other internal combustion engine into which the cooling apparatus of the invention has been built;

FIG. 2 is a sectional view taken along the lines 2--2 in FIG. 1, shown at an enlarged scale; and

FIGS. 3 and 4 are fragmentary axial sections, shown at a still larger scale, of the pairs of tubes 9, 20 and 10, 21 of FIG. 2 respectively.

Description of preferred embodiment The engine fragmentarily shown in FIG. 1 includes a cylinder 1, a piston 2 having a hollow head 3, a piston rod 4 with a crosshead 5, and a crank housing or crankcase 6. Between the cylinder 1 and the crankcase 6 is disposed an air chamber 7 separated by means of partitions 8 from the crankcase.

Cooling of the piston is effected with the aid of two pairs of tubes 9, 20 and 10, 21. The tubes 9 and 10 are affixed at one end, the upper end thereof in the embodiment illustrated, to the piston and they move therewith.

They extend parallel to the direction of travel of the piston. The tubes 20 and 21 are affixed at one end, the lower end thereof in the embodiment illustrated, to the inside of a stationary chamber 12. The tubes 20 and 21 have an outside diameter smaller than the inside diameter of tubes 9 and 10, and their free upper ends extend in telescoping relation with and inside of the free, lower ends of the tubes 9 and 10 respectively. The tubes 9 and 10 may have the same diameter. Packings 11 are provided between the movable tubes 9 and 10 and the chamber 12, which is closed ofi from the crankcase 6.

Conduits 13 and 14 connect to the interior of the stationary tubes 20 and 21 respectively at the lower ends thereof, and serve respectively for the supply of coolant to the piston and for the withdrawal of coolant therefrom. An additional conduit 15 leads out of the chamber 12 at the lower end thereof for removal of coolant accumulating therein, and a conduit 22 provides communication between the upper portion of chamber 12 and the atmosphere outside the engine (FIG. 2). The conduits 14 and 15 may be provided with sight glasses 16 and 17 (FIG. 1).

Referring to FIG. 3, the upper end of the stationary coolant inlet tube 20 has affixed thereto an annular ejectorshaped nozzle member through which coolant may be sprayed under pressure into the cavity 3 of the piston via the movable tube 9. The member 30 is provided at its lower end with a spray nozzle opening 31 which leads into an ejector bore or throat 32. An annular enlargement 33 is provided at the lower end of the ejector throat 32, and this enlargement connects via conduits 34, extending obliquely outward and downward (i.e. backwards, with respect to the flow of coolant through member 30) to an annular space 35. The space 35 may be formed at the cylindrical interface between the member 30 and a sealing or packing sleeve 36 disposed between the member 30 and the inside wall of the movable tube 9, and affixed to the former. The sleeve 36 has a number of circumferential grooves 37 formed in its outer surface, and the lowest groove or grooves 37 are connected by apertures 38 with the space 35. The tube 20 has affixed to the exterior thereof, below the nozzle member 30, a ring 28 having a radial clearance X (FIG. 3) from the inside wall of the tube 9. This clearance is smaller than the clearance between tubes 20 and 9 and is so dimensioned as ot permit a desired air flow therethrough and may amount for exampie to some 0.2% of the internal diameter D of the tube 9.

During operation of the engine, a suitable coolant such as water flows under a pressure of from 3 to 4 atmospheres through the nozzle 31 and the ejector opening 32. The flow of water creates a negative pressure in the hollow space 33. By means of this reduced pressure the medium, liquid or gaseous, in the annular space 29 between the moving tube 9 and the stationary tube 20 is aspirated through the openings 38, the hollow space 35 and the bores 34 into the central ejector bore 32. In this way air is aspirated from the chamber 12 (which is connected to the exterior atmosphere through the conduit 22), and this air is added to the cooling water. There is thus provided to the cooling space 3 of the piston a mixture of air and water, in a manner which in and of itself is already known. Simultaneously, water which may have penetrated into the annular space between the tubes 20 and 9, for example by leakage past the sleeve 36, is aspirated and returned to the stream of cooling water flowing to the piston. By means of the ejector operation thus provided for the coolant supply tube 20, it is possible to effect substantially complete suppression of the passage of water into the chamber 12 via the annular space between the moving tube 9 and the stationary injection tube 20.

FIG. 4 shows a corresponding construction for the free end of the stationary return tube 21. The tube 21 is provided at its upper end with an annular member 38'. The upper end of this member has a nozzle-like opening 40, followed at the lower end thereof by an ejector-shaped throat or bore 41. At the junction of the two is provided a hollow annular space 42 of enlarged diameter, similar to the space 33 in the member 30 already described.

Upon the downward streaming of the cooling water which returns from the piston, a negative or reduced pressure is developed in the space 42. The hollow space 42 is connected by bores 43 with a hollow space 44 similar to the space 35' of the tube 20. A packing sleeve 45, simi lar to the sleeve 36 and having circumferential grooves 46 in its outer surface, fits between the return tube nozzle member 38' and the inside wall of the movable return tube 10. The lowest of the grooves 46 connects via openings 44' with the annular space 44, which functions as a storage space for liquid in a manner similar to that of the annnlar space 35 of FIG. 3.

The stationary return tube 21 carries, below the return nozzle member 38', a ring 47 generally similar to the ring 28 of FIG. 3. The ring 47 has however a smaller clearance from the tube 10 than the clearance X of FIG. 3, since there is less necessity for an aspiration of air in the case of tube 21 than in the case of tube 20.

As with the construction of FIG. 3 previously described, in the case of the return tube of FIG. 4 also, water which has penetrated into the annular space between tubes 10 and 21 is aspirated by the suction effect of the ejector provided in the member 38.

By means of the present invention, flow of the cooling medium such as water into the chamber 12 is substan tially prevented. This avoids contamination of the coolant from oily residual materials penetrating from outside the movable tubes, even with a substantial simplification in the packing 11 between the space beneath the piston and the inside of the chamber 12. With the construction of the invention, this packing need not have a filtering or cleansing action, and suflices if it simply preserves the existing differences in air pressure.

Storage spaces for coolant are formed by the grooves 37, 46 and the hollow spaces 35 and 44. Since tubes 9 and 10 move up and down with the piston, the streaming of coolant in the tubes 20 and 21 occurs in a more or less pulsating fashion so that the suction effect of the ejectorshaped end portions thereof is similarly pulsating. The coolant not aspirated during a phase of reduced suction effect can be collected in these storage spaces, especially the spaces 35 and 44, and then removed or aspirated during the next phase of increased suction effect.

There is achieved an improved suction effect by virtue of the fact that the bores 34 and 43 extend obliquely outward and backward (with respect to the direction of coolant flow through their associated ejectors). The air or water aspirated into the coolant stream is added to the latter substantially in the latters direction of fiow and consequently does not impose an undesirable turbulence on the stream of coolant fluid.

Consistently with the invention, the provision of an ejector as hereinabove described may be applied to the inlet or injection tube through which coolant flows into the piston, without being applied also to the outlet or return tube. Indeed, it may successfully be applied to the inlet tube even in constructions in which the tube 21 is absent, the movable return tube (such as that shown at 10 in the drawings) simply discharging the returning coolant into the chamber. Even with such a construction there is achieved a great reduction of the amount of water flowing into the chamber since the leakage into the chamber which would otherwise occur at the junction between the stationary and movable inlet tubes is minimized.

While the invention has been described hereinabove in terms of a presently preferred embodiment, the invention itself is not limited thereto. For example, it is of course not necessary for the stationary tubes to terminate within the chamber 12. Rather, their lower ends may pass out, at liquid-tight seals, through the bottom of that chamber. More generally, the invention comprehends all variations on and departures from the embodiment so described which properly fall within the spirit and scope of the appended claims.

I claim:

1. Apparatus for liquid cooling of a piston in an internal combustion engine, said apparatus comprising a chamber closed off from the engine crankcase, a plurality of movable tubes affixed at one end to the piston and extending at their other ends into the chamber, and at least one stationary tube having a free end extending for all positions of the piston in telescoping relation with the other end of one of said movable tubes, wherein the improvement comprises an ejector-shaped member supported adjacent the free end of said one stationary tube, said member having a space within said one stationary tube in which flow of liquid through said member creates a reduced pressure, and conduit means connecting said space with the annular space between the portions of said stationary tube and said one movable tube which are in telescoping relation.

2. Apparatus according to claim 1 wherein said ejectorshaped member creates a reduced pressure in said firstmentioned space upon flow of liquid through said stationary tube toward said one movable tube.

3. Apparatus according to claim 2 including a ring disposed on the exterior of said stationary tube in the part thereof having telescoping relation with said one movable tube, said ring having a smaller clearance from the inner Wall of said one movable tube than does said stationary tube.

4. Apparatus according to claim 1 wherein said ejectorshaped member creates a reduced pressure in said firstmentioned space upon flow of liquid through said stationary tube from said one movable tube.

5. An apparatus according to claim 1 wherein said member is an annular member having an axis, wherein said first-mentioned space constitutes an annular enlargement of the opening through said annnlar member, and wherein said conduit means comprise a plurality of bores disposed about said axis and extending outwardly from said first-mentioned space.

6. Apparatus according to claim 5 wherein said bores extend obliquely to said axis.

7. Apparatus according to claim 1 wherein said member has formed therein an annular space communicating with said conduit means intermediate the ends thereof.

8. Apparatus according ot claim 2 including means to permit withdrawal of liquid accumulating in said chamber, and means to permit the maintenance of atmospheric pressure within said chamber.

References Cited UNITED STATES PATENTS 3,230,940 1/1966 Hofmann 123-4136 3,230,941 1/1966 Hofmann 123-4136 3,230,942 1/1966 Hofmann 123-4136 3,230,943 1/1966 H-ofmann 123-4136 WENDELL E. BURNS, Primary Examiner.

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