US3391610A - Steam engines for ship winches having gravity flow of condensate through the slide valves - Google Patents

Description

July 9, 1968 L. SAXE 3,391,610

STEAM ENGINES FOR SHIP WINCHES HAVING GRAVITY FLOW 0F CONDENSATE THROUGH THE SLIDE VALVES Original Filed Oct. 22, 1964 2 Sheets-Sheet 1 mvcm'onz LUDVIG SAXE ATTVS.

July 9, 1968 L. SAXE 3,391,610

STEAM ENGINES FOR SHIP WINCHES HAVING GRAVITY FLOW OF CONDENSATE THROUGH THE SLIDE VALVES Original Filed Oct. 22, 1964 2 Sheets-Sheet :3

ATTYS.

United States Patent C 4 Claims. c1. 91-448) ABSTRACT OF THE DISCLOSURE A steam engine particularly adapted for use as a ship mooring winch, having two main double-acting cylinders, a slide valve underlying each cylinder and a reversing valve common to both cylinders which underlies the two slide valves. The common reversing valve is connected to the main live steam passage and the main exhaust passage which are positioned below the reversing valve. The ports and connections which afford communication between the respective valves and the cylinders are positioned so that the condensate forming in these elements can drain by gravity through the valves and into the passages continuously both when the engine is operating and when it is standing idle with the full working steam pressure in the cylinders and steam inlet passages and valves.

This case is a continuation of Ser. No. 405,727, filed Oct. 22, 1964, now abandoned.

The present invention relates to steam engines and particularly to engines for ship winches. The object of the invention is to provide an engine which is self draining, so that collection of condensate in the steam engine is avoided.

In all known types of steam winches for ships, the axes of the crank shaft, the cylinders, and the valve casing are arranged in the same plane, usually horizontal. A principal reason for this is that this arrangement permits the use of simple connections for the transmission of the eccentric motion from the crank shaft to the slide valve in the valve casing. Water usually condenses and collects in the cylinders, valve casings, and the reversing valve casing when the engine is stationary as Well as when the engine is running at low speed, and especially in cold weather. On account of corrosion, it is not usual to insulate steam engines for deck machinery. The winches therefore are provided with a great number of places to drain of the condensate, and experience has proved that it is difficult to make the deck hands be sufliciently careful with the draining. Additionally most automatic mooring winches have relief valves to counteract water shock in the cylinders, but such relief valves must be provided with a very great flow area to effectively prevent water shock.

In order to prevent the water collections from freezing and cracking the castings, it is usual to let the winches run idle in cold weather and this has led to damage to the drive gearing and bearings. Such engines often do not get regular maintenance and lubrication.

A winch is an engine and, as such, ought to be attended by the engine room staff. It is, however, natural to let those who attend the winches, i.e., the deck hands, have the supervision thereof. The deck hands concentrate usually more upon descaling and painting than draining and lubrication, and it is therefore an important requirement to the deck machinery that it should be perfectly safe and necessitate as little supervision as pos- "ice sible. This is especially important today when the tendency is automation of the work on board.

In accordance with the invention, the valve casing is arranged lower than the cylinders and the reversing valve casing is arranged lower than the valve casing, so that it is possible to arrange the steam channels such that it will be no water pockets in the steam engine. The live steam will then all the time flow upwardly from the inlet of the reversing valve casing to the cylinders and the exhaust steam will flow downwardly from the cylinders to the outlet of the reversing valve casing. The need of draining is then reduced to a draining passage from the live steam pipe but in any case, draining at this point is required due to the possibility of water collection in the pipe itself. One can, however, mount a condensate outlet between the live steam pipe and the exhaust passage before or after the steam valves of the winch.

To have a better understanding of the invention reference is had to the following description of an embodiment shown in the drawings.

FIG. 1 is an end elevation of a steam winch according to the invention, having a pair of cylinders, one of which is broken away for the purpose of illustration, for example along the line AA of FIG. 3; and

FIGS. 2 and 3 are sections along the lines B-B and C-C respectively of FIG. 1.

Referring now to the drawings, the steam winch includes two main double-acting cylinders 7, each having a piston 11 and a piston rod 12, as shown, a slide valve casing 4 for each cylinder and a common reversing valve 1. Steam ports are provided in the bottom of each cylinder 7 at the fore and aft ends, as indicated at 6 and 6a respectively, each serving as both an inlet and an exhaust passage for the steam. The valve casing 4 is mounted below each cylinder and is provided with a hollow slide valve 5 having an operator 14 for displacing the valve to alternately connect fore and aft upper ports 15 and 15a with either a central lower port 16 or one of the end chambers 17 and 17a, which are interconnected through the hollow valve 5. The end port 15 is connected to the steam port 6; the end port 15a is connected to the steam port 6a; the central port is connected to a transfer port 3 in the reversing valve 1; and the end chamber 17 is connected at its bottom to the other transfer port 8 of the valve 1. The valve 1 has a hollow valve element 2 having an operator 18 for displacing the element to alternately connect the transfer ports 3 and 8 with a central live steam passage 21 and an exhaust passage 22. The passage 21 is connected to a source of live steam through a live steam valve (not shown).

From the live steam valve, the steam flows into the passage 21 of the reversing valve casing 1, and, in the illustrated position of the valve, is guided by the reversing valve 2 to the transfer port 3 for the respective cylinder parts. By displacing the reversing valve 2 to its alternate position, the live steam may be led to the other transfer port 8. From the port 3, the steam flows up to the valve casing 4 and is led further up by the slide 5 to one of the steam ports of the cylinder and up into the cylinder 7. As shown in FIG. 2, where the piston is near the start of its forward stroke, the valve 5 directs the steam to the aft ports 15a and 6a to drive the piston forwardly. As shown in FIG. 3, where the piston is near the end of its rearward stroke, the valve 5 direct the steam to the forward ports 15 and 6 to drive the piston rearwardly. On the opposite sides of the pistons, the exhaust steam is dispelled through the valve casing 4 to the other transfer port 8 into the exhaust passage 22. In FIG. 2, the steam flows down through the ports 6 and 15, and the end chamber 17; whereas in FIG. 3, the steam flows down through the ports 60 and 15a, the end chamber 17a, the

hollow part of the valve 5, and the end chamber 17. At the end of the stroke of each piston, the operator 14 of the slide valve 5 is automatically displaced to reverse the flow of steam into and out of the associated cylinder.

The vertically stacked arrangement of the cylinders, slide valves, and reversing valve, and the disposition of the ports and passages in the bottom of their associated casing provides a constantly sloping passage which insures that any water which may condense in the winch engine may flow down by gravity only and be discharged either through the exhaust passage 22 or into the live steam passage 21. To remove the condensate from the live steam side, a single draining passage may be provided to drain the live steam pipe. For example, one can mount a condensate outlet between the live steam passage and the exhaust passage before or after the steam valve of the winch. Preferably, the condensate outlet extends from the lowest part of the live steam side of the winch to the exhaust side which thereby drains the condensate in the engine as well as the condensate in the live steam plpe.

If one desires to drain olf the small amounts of condensate which might collect in the end chamber 17a of the valve casing on the crank side of the slide, one can arrange a special drain channel 9 from this part of the valve casing to the transfer port 8.

What is claimed is:

1. An engine having a main live steam passage and a main exhaust passage comprising at least one cylinder disposed substantially horizontal and having steam ports at the opposite ends, each serving both as an inlet and an exhaust passage for the steam, a piston slidable in said cylinder intermediate said steam ports, and a slide valve casing having a slide valve, upper ports connected to said steam ports, and lower ports connected to said main live steam and exhaust passages; the improvement wherein said valve casing is positioned below said cylinder, said steam ports being in the bottom of said cylinder so as to drain any condensate by gravity into said valve casing through said upper ports, said lower ports being in the bottom of said slide valve casing, and said live steam and exhaust main passages being below said slide valve casing, to afford flow of any condensate by gravity, from said valve casing through said lower ports into said main passages.

2. An engine according to claim 1 including a reversing valve casing connected intermediate said main passages and said lower ports operable to reverse the flow of steam through said engine, characterized wherein said reversing valve casing is positioned below said slide valve casing so as to receive said condensate flowing by gravity from said lower ports in its travel to said main passages.

3. An engine according to claim 2 wherein said engine includes at least two similar cylinders, pistons, and slide valve casings respectively and wherein said reversing valve casing is common to and connected to both said slide valve casings, said reversing valve casing being positioned below the level of said slide valve casings to receive condensate from the engine.

4. An engine according to claim 1 wherein said slide valve casing is substantially horizontal and said upper ports thereof are positioned on opposite sides of the transverse center plane of said casing, the lower port connected to said main live steam passage being positioned intermediate said upper ports, said casing including opposed end chambers outboard of said upper ports, the port connected to said main exhaust passage being positioned in the bottom of one of said end chambers and including a connection from the bottom of the other end chamber sloping downwardly to connect with said main exhaust passage.

References Cited UNITED STATES PATENTS 314,341 3/1885 Moore 91-448 554,022 2/1896 Forslund 91-448 562,305 6/1896 Knight 91448 972,368 10/1910 Hagman 91-448 1,028,127 6/1912 Miller 91448 1,155,811 10/1915 Hartung 91-444 741,828 10/1903 Presnell 91-464 MARTIN P. SCHWADRON, Primary Examiner. EDGAR W. GEOGHEGAN, Examiner.

B. L. ADAMS, Assistant Examiner.

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