US2072001A - Propeller shaft lubricating apparatus - Google Patents

Description

Feb. 23, 1937.

H. A. GUTHANS PROPELLER SHAFT LUBRICATING APPARATUS Filed July 21, 1933 3 Sheets-Sheet l ll i i... if; ii:

INVENTOR Ham/a fl. ufhqns ATTORNEY Feb. 23, 1937. I H. A. quTHANs Q 93, PROPELLER SHAFT LUBRICATING APPARATUS r Filed Jul 21, 1933 s Sheets-Sheet 2 N I N 0 ATTORNEYS Fgb. 23, 1937. H. A. GUTHANS Filed July 21, 1933 3 Sheets-Sheet 3 INVENTOR Ham/a A. Gui/mm Lib-FM ATTORNEY Patented Feb. 23, 1 937 UNlTED STATES PATENT OFFIQE PROPELLER SHAFT LUBRICATING APPA- RATUS 2 Claims.

This invention relates to improvements in lubricating apparatus for the propeller shaft of watercraft and stem bearings thereof.

As will be more fully apparent from the following detailed description, the invention contemplates the provision of means for forcing grease or other lubricant to the outboard bearing under pressure against the force exerted on packing by a spring-pressed gland, the arrangement being such that sand, grit and water are kept out of the bearing and at the same time wear on the packing is automatically compensated for.

One embodiment of the invention is illustrated in the accompanying drawings, in which Fig. 1 is a longitudinal section through the stern portion of a twin screw ship, parts being broken and omitted in the interest of clearness; Fig. 2 is a fragmentary detail section on line 22 of Fig. 1 illustrating means for driving a pump from the propeller shaft, which pump in turn actuates the piston of a lubricating device; Fig. 3 is an enlarged detail in longitudinal section through the shaft bearing illustrating the improved spring-pressed gland and related parts; Fig. 4 is a transverse section on line 4-4 of Fig. 3; Fig. 5 is a longitudinal section on line 55 of Fig. l; Fig. 6 is a transverse section on line 66 of Fig. 3; Fig. 7 is a detail view of the gland and its casing, the upper half of each being shown in side elevation and the lower half in central longitudinal section, the view also illustrating the relative positions of a certain guide pin and its spring and a special fastening bolt to be hereinafter described; Fig. 8 is a detail end view of the gland as viewed from the left of Fig. '7.

Referring in detail to the drawings, 8 represents a propeller of a ship, carried by shaft It which carries shrunk-n sleeves l2 and M of high carbon steel. These sleeve portions revolve, respectively, in the outboard bearing l6 and the inboard bearing ll. The outboard bearing is carried by a hub l8 formed in part of conventional type of strut casting 20 suitably secured to the ships framing. The usual stern tube 22 surrounds that portion of the shaft located between the bearings l6 and El and suitable hull plating 2 3 is secured in a conventional manner to the stern frame 26.

The present invention is concerned chiefly with the lubricating apparatus for the outboard bearing and further description of the ship structure is, therefore, unnecessary for a full understanding of the invention.

Located within the hull of the ship, the shaft H3 carries an eccentric 28 which is connected through eccentric strap 3%] and pitman rod 32 with an arm 3t carrying a pawl 36 which coacts with a ratchet wheel 38 constituting a drive for a pump 48. This pump is of known construction and need not be described in detail, except to say that it is driven from the shaft it and draws liquid from a supply tank 42 by Way of pipe i l and forces such liquid through pipe 46 into the chamber 48 of the lubrication cylinder 59 so as to force the piston 52 therein upwardly. The chamber 54 on the opposite side of the piston contains a quantity of lubricant such as grease or the like supplied in a manner hereafter described. When the pump moves the piston 52 up, such lubricant is forced through a duct 58 to the interior of the bearing It, thus lubricating the shaft and its bearing. This lubricant, being forced under a constant pressure so long as the shaft is rotating, serves to prevent sand and grit from entering the bearing.

The bearing is provided with a recessed portion 58 to accommodate several turns of plaited raw hide packing Gil as well as the end of a slidable gland 62. This gland is yieldingly pressed into engagement with the packing by a number of springs (54 so that as the packing rings gradually Wear away, the gland follows up the wear and insures proper fit between the packing and the shaft throughout the life of the packing. The spring pressure also counteracts to some extent the pressure exerted by the lubricant.

The gland is formed with a plurality of outwardly extending lugs 86 which slidingly engage grooves 68 formed in the gland casing 79 which encloses the gland. The casing it is secured to the bearing by bolts H (see Fig. having intermediate head portions it which engage a flange 76 formed on the bearing and thus serve to bolt the bearing to' the hub H8. The heads 'M of these bolts are accommodated in recesses l'ii formed in the gland casing. The outer shanks 8% of the bolts 72 pass through openings in lugs 32 on the gland casing and nuts 8d serve to rigidly secure the casing to the bearing as will be clear from the drawings.

The springs 64 which yieldingly press the gland against the packing are guided on pins 86 having shoulders abutting the end wall at of the gland formed in the gland, these holes being centered in two instances with the lugs 66, as shown at 92 in Figs. 7 and 8.

Where the spring guide pins align the lugs, the latter are arranged as indicated at Q-l in Fig. '7 to accommodate the springs 64. As thus constructed, it is clear that the spring-pressed longitudinally movable gland is entirely enclosed by the casing and that because of the provision of the guide lugs, which slidingly engage the recessed parts of the casing, the spring pins and springs are relieved of strains which might be set up due to the tendency of the shaft to rotate the gland, although normally such tendency of the gland rotation is overcome by the presence of a lubricant which is being constantly extruded in small quantities between the gland and the shaft.

In some cases, I provide a shell-like guard plate comprised of two semi-circular plates which encircle the gland casing, said plates being indicated at GI in Fig. 3. This plate is electrically welded to the rear end of the bearing hub I8.

There is a peculiar and special interdependence between the spring-pressed gland and the pressure lubricating devices as they jointly cooperate to permit the gland to be unfailingly urged against the packing by the yielding spring pressure so as to constantly compensate for the wear taking place on the packing, thus effectively preventing the entrance of sand, grit, or water into a shaft bearing. Thus, it is clear that the pressure lubricating devices are effective to constantly extrude a small amount of lubricant outwardly against the water pressure, while at the same time the gland is being pressed inwardly against the packing by the several springs 64 and the water pressure. As fast as the packing wears away, the springs compensate for the wear and make an effective yielding seal counteracting the pressure of the lubricant. Thus, the cooperating instrumentalities are effective to maintain excellent lubrication and to exclude foreign matter from the interior of the bearing.

The bearing I5 is provided with a plurality of grooved portions 36 which permit the lubricant to more readily flow lengthwise of the shaft. For single screw vessels, these grooves extend-to the forward end of the bearing to admit the lubricant from the stern tube into which it enters by way of the lubricant duct 55. For multiple screw vessels, the bearing in addition to a plurality of grooves also has a plurality of passages 98 which communicate with an annular chamber it!!! opening into passageways I62 formed in the diagonal legs of the strut casting 2!]. These passageways communicate with the lubricant duct 55 above referred to. There is a gauge I64 which indicates the pressure at which the lubricant is being supplied.

Referring further to the pump 40 and thelubricating cylinder 54 and related parts, the pump is adapted to constantly force the lubricant to the bearing as long as the propeller shaft is turning. Thus, the supply of lubricant at a predetermined rate is automatically maintained. Means are also provided for periodically replenishing the supply of lubricant to the lubricant cylinder 50 after the piston 52 has traveled to the top of the cylinder and exhausted its supply. The refilling of the piston need only be done at long intervals and the necessity for refilling can be determined by suitable markings on the piston rod 52a which moves upwardly with the piston, therefore, it serves as a telltale.

With the pump 40 in operation, oil or other suitable fiuid is drawn from the supply tank 42 and forced into the lower chamber 48 of the lubricant cylinder Ell, thus moving the piston upward and extruding the grease from the chamber 54 by way of duct 56 and passages 98 and grooves 96 to the interior of the bearing.

The piston 52 acts in a manner somewhat analogous to a hydraulic ram and its rate of upward movement is controlled by a relief valve I06, located in a pipe I til communicating with the pump outlet pipe 66 and leading to the bottom of the cylinder 50. The relief valve I96 can be set so as to return part of the pumped liquid to the tank 42 by way of the pipe connection I III. There is a normally closed valve IIZ also connected between the pipe I08 and the supply tank 42, which valve is merely opened at the time the piston 52 is being reset to its lower position in order to permit the oil from the chamber 48 to be rapidly returned to the supply tank A2.

For quickly filling the chamber 5 3 of the lubricant cylinder, I preferably provide a lubricant reservoir I I4 having a plunger I I5 therein. This reservoir has an inlet hopper I It with a gate valve I20 therein. Steam, compressed air or any suitable pressure medium can be supplied by pipe I22 to the space on the opposite sides of the plunger IIE of the reservoir so as to move it up or down. When the plunger moves upwardly, the lubricant therein is discharged by way of pipe I24 to the top of the upper chamber 54 of the lubricant cylinder. After the cylinder is filled, the valve I26 in said pipe I24 should be closed.

To cause the plunger HS in the reservoir to move upwardly, a valve I28 in the supply pipe is opened while the valve I30 in the branch pipe I32 leading to the space above the plunger is closed. Thus, the pressure will move the plunger upwardly to force the charge of lubricant through the then open valve I26 to the chamber 54 above the piston 50 of the lubricant cylinder. At this time, the valve I I2 of the supply tank willbe opened and the fluid below the piston 52 will be returned to the supply tank 42.

To replenish the supply of lubricant in the reservoir I I4, valve I28 in the supply line is closed and bleeder valve I34 is opened. With the gate valve I2!) closed, the valve I3il is opened. This permits admission of pressure medium within the space in the reservoir II4 above the plunger i it and thus forces it downwardly, the pocketed air or other pressure medium being discharged through the bleeder valve I34. With the plunger I I6 at the bottom of the, reservoir, the bleeder valve is closed and valve I30 is closed. The gate valve I2il is then opened and the lubricant is inserted through the hopper Ila. Then upon closing of the gate valve, the reservoir is in condition to intermittently transfer charges of lubricant to the upper chamber 54 of the piston by proper manipulation of the valves in a manher which will be apparent from the above description.

The apparatus described involving the use of the yieldingly pressed, self wear-compensating packing gland will provide sufficient lubricant to the bearing in the stern tube of the vessel and the lubricant will be forced under substantially constant pressure in direct ratio to the speed at which the propeller shaft rotates. The arrangement is such that the lubricating pressure can be very closely regulated and maintained at a point slightly greater than the water pressure outside and thus in a practical sense there will be substantially no opportunity for sand, or grit to find its way into the interior of the bearing.

Once the apparatus is adjusted, no further attention is required other than filling the system at occasional intervals dependent upon the holding capacity of the lubricant cylinder. This filling operation can be rapidly accomplished by means of the reservoir and plunger mechanism described so as not to interfere with the constant lubrication. Only such an amount of lubricant as is necessary to replace a small amount forced past the packing gland is required to maintain the constant pressure in the stern tube. The operation is such that it is entirely automatic and when the pressure in the stern tube bearing reaches a predetermined point, striking a balance with the outside water pressure and the yielding pressure exerted against the gland by the springs, an immaterial quantity of lubricant is expended. Should the lubricant pressure momentarily drop as the result of leakage past the spring-pressed packing gland, additional lubricant will be immediately and automatically fed to replace the loss and to restore the pressure balance to normal.

While I have described with great particularity the specific embodiment of the invention herein illustrated, it is to be understood that various modifications and substitutions of equivalents may be made by those skilled in the art Without departure from the invention as defined in the appended claims.

What I claim is:-

1. A seal for a submerged shaft, having a cas ing, a bearing sleeve mounted therein, said hearing sleeve having a recessed packing chamber at one end, a packing wholly enclosed in said chamber, a gland having one end slidable in the chamber and engaging said packing, a chambered casing bolted to the bearing sleeve and wholly enclosing the gland and circumferentially spaced springs interposed between one end of said chambered casing and said gland for yieldingly pressing the latter against said packing, said casing carrying longitudinally extending circumferentially spaced guide pins for said springs and having longitudinally extending grooves and said gland having lugs making a sliding fit therewith.

2. A seal for a submerged shaft, having a casing, a bearing sleeve mounted therein, said bearing sleeve having a recessed packing chamber at one end, a packing wholly enclosed in said chamber, a gland having one end slidable in the chamber and engaging said packing, a chambered casing fixedly secured to the bearing sleeve and wholly enclosing the gland, and circumferentially spaced springs interposed between one end Wall of said chambered casing and said gland for yieldingly pressing the latter against said packing, said end Wall of the casing carrying longitudinally extending circumferentially spaced guide pins for said springs, the chambered casing and the gland having coacting interengaging portions allowing a sliding axial movement of the gland relatively to the chambered casing.

HAROLD A. GUTHANS.

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