US2553850A - Apparatus for scavenging hydrodynamic machines - Google Patents

Description

May 22, 1951 J. K. DOUGLAS APPARATUS FORA SCAVENGING HYDRODYNAMIC MACHINES 3 Sheets-Sheet 1 Filed May 18, 1946 ATTORNEY May 22, 1951 J. K. DOUGLAS I APPARATUS Foa scAvENGING HYDRODYNAMIG- uAcHIwEs 3 Sheets-Sheet 2 Filed May 18, 1946 //I////////// f //V/A FIG. 5

J. K. DOUGLAS May 22, 1951 2,553,850 APPARATUS FOR SCAVENGING HYDRODYNAMIC MACHINES Filed May 18, 1946 3 Sheets-Sheet I5 FIG. 3

FIG. 6

To Tank INVENTOR JAMES K. DOUGLAS iatented May 2v2, 1'95'1 narran s'rATss PATENT oFFlc-i;

APPARATUS FOR SCAVENGING HYDRO- DYNAMIC MACHINES James K. Douglas, Shorewood, Wist., assigner to rEhe Oilgear Company, Milwaukee, Wis., a corporation of Wisconsin @privation May 1s, 1946, serial No. @70h66 (ci. S-4) 12 ciaims.

This invention relates to the removal of leakage liquid from the interiors of hydrodynamic machines which may be mechanically driven pumps or `may be hydraulic motors energized by liquid from pumps.

In all rotary hydrodynamic machines there is more or less internal leakage of the motive liquid, which is ordinarily a good grade of lubricating oil, and this leakage oil must be removed from the case of the machine for the reason that, due to the viscous nature of the oil, a substantial accumulation of oil in the case of themachine will impose a drag upon the rotating parts and thereby decrease the eiiic'iency of the machine. V

It Vis common practice to place a pump above areservoir or tank which contains a supply of oil for the pump and into which leakage oil is drained from the pump by gravity. This arrangement requires either that the pump be supercharged by an auxiliary pump or that the pump suck oil from the reservoir. In the latter case, partial vacuums are created in the cylinders on the intake side of the pump with the result that the oil entering the cylinders is partially gasied or aerated and causes the elasticity of the oil discharged by the pump to be considerably increased which isaJ very objectionable condition. This condition is sometimes overcome by arranging the reservoir above the pump but such an arrangement requires 4a scavenging pump to raise the leakage oil from the pump case to the reservoir.

The present invention has as an object to remove leakage liquid from the case of a hydrodynamic machine and to raise it to a higher level without the aid of an auxiliary pump or similar device.

Another object is to elevate leakage liquid from the case of a hydrodynamic machine to a higher level in response to rotation of the rotor of the machine. y

Other objects and advantages will appear from the description hereinafter given of hydrodynamic machines to which the invention has been applied.

Different forms of the invention are embodied in the hydrodynamic machines shown in the accompanying drawings in which the views are as follows:

Fig. 1 is in part a side elevation and in part a' central longitudinal section through a reversible pump to which one form of the invention has beenapplied,v the main part of the" pump 2 Y rotor being shown in elevation with portions thereof broken away to expose other parts'.

Fig. 2 is a transverse section through thev pump taken substantially on a line 2-2 of Fig. 1.

Figs. 3 and 4 are views similar, respectively, to the lower portions of Figs. 1 and 2 but with the rotor omitted and showing a diierent form of the invention, the plane of Fig. 3 being indicated by the line 3 3 of Fig. 4 and the plane of Fig. 4 being indicated by the line 4-4 of Fig..3. Fig. 5 is a View similar to the lower right hand portion of Fig. 2 but showing another form of the invention.

Fig. 6 is a View of the lower part cfa hydraulic. motor to which a form of the inventionhas been applied, the view beingin part a transverse sectiony thru the case of the motor and in part an end elevation of the rotor of the motor.

For the purpose of illustration, the invention has been shown applied to radial hydrodynamic machines of the rolling piston type Such as shown in Patent No. 2,074,068 but it canas readily be applied to other types of radialv machines and to axial hydrodynamic machines VVit only being necessary that the outer periphery of the rotor ofthe machine be circular andbe free from protuberances of substantial height.

Figures 1 and 2 The pump shown in these figures hasI its mechanism arranged within andv supported by a case Iv which is closed at its front end by a removable endv head 2 and is provided at its rear end" with a distributing block 3 whichv may be connected to opposite sides of an externalv circuit as'represented by pipes 4 and 5.

Pump case l encloses a displacement varying member or slide block Fi, which is restrained from axial movement by end head 2 and by the rear wall of case l. Slide block is supported upon two lower slide bars l, which are iixed tothe lower wall `of case I, and it is restrained from vertical movement by two upper slide bars 8 which are iixedto the upper wall of case I.

The arrangement is such that slide block E may be moved toward one or the other side of case I to vary theV rate and direction of p ump delivery' but it is restrained frommovemerit'in any other direction. Movement of slide block 6 may be effected in any suitable manner such as by means'of a screw S, which is fixed thereto, and a handwheel l which isv threaded upon screw/ Q and is restrained from axial movement by case l and by a cap Il carried thereby.

Slide block 6 encloses a rotor I5 which includes a hollow outer rotor or thrust member I6 and an inner rotor or Cylinder barrel I1. Thrust member Iii is rotatably supported within slide block 6 by means of bearings IB and I9 carried thereby so that it is movable with slide block to vary the displacement of the pump. Cylinder barrel Il is rotatably supported within thrust member I3 upon a valve shaft or pintle 2U which extends through the rear end of thrust member I6 and is rigidly secured in distributing block 3. Rotation of cylinder barrel I'l upon pintle is eiected by means of a shaft 2l which is iixed to cylinder barrel Il and extends through end rhead 2 for connection to a source of power.

Pintle 20 has formed therein two ports 22 and 23 which are arranged diametrically opposite each other, two axial passages 24 which extend rearward from port 22 and two axial passages 25 which extend rearward from port 23. Passages 24 and 25 communicate, respectively with pipes l and 5 through passages which are formed in distributing block 3 but are not shown in the drawings.

Cylinder barrel Il has formed therein a plurality of radial cylinders 26 each of which registers with ports 22 and 23 alternately as cylinder barrel I7 rotates upon pintle 20. A piston 2l is fitted in each cylinder 2E and has its outer end shaped to make suitable contact with an inclined reaction surface 28 which is fixed to or formed upon the inner periphery of thrust member IE.

When slide block 5 is in its neutral position, the axis of thrust member IB is coincident with the axis of rotor Il and rotation of rotor I l will not result in the delivery of oil by the pump but, when slide block 6 is shifted in one direction or the other from its neutral position and cylinder barrel I7 is rotated, the pump will deliver oil in a direction and at a rate dependent upon the direction and distance slide block 6 is shifted from its neutral position as fully explained in Patent No. 2,074,068.

For example, if slide block E is offset toward the left from its neutral position as shown in Fig. 2 and cylinder barrel I 'l is rotated in a counterclockwise direction as indicated by the arrow, the pistons 2'! in the lower half of cylinder barrel I'F will be forced progressively inward by reaction Surface 28 and they will eject oil from their cylinders 26 through port 23, passages 25 and distributing -block 3 to one side of an external circuit such as indicated by pipe 5.

At the same time, the pistons 21 in the upper half of cylinder barrel Il will move progressively outward and their cylinders 26 will be lled with oil through port 22, passages 24 and distributing block 23 from the other Side of the circuit such as indicated by pipe 4. Complete lling of the cylinders 26 on the intakeside of the pump is assured by a supply of oil in a reservoir or tank 29 which is arranged above the pump and is connected to or forms a part of the return side of the external circuit such as by being connected to pipe 4.

The arrangement shown requires delivery of oil in only one direction but, if reversal of flow in the external circuit is required, it is only necessary to connect reservoir 29 to both sides of the pump through automatic valve mechanism which permits oil to flow freely from the reser- Voir to the pump but prevents flow from the pump to the reservoir. Since such an arrangement is well known, it has not been illustrated.

When a hydrodynamic machine is in operation, small volumes of oil escape across the face of its valve, other small volumes of oil escape past its pistons and this leakage oil if not removed will accumulate in the lower part of the case of the machine and soon reach such a depth that the lower part of the rotor` is immersed therein.

Due to its viscous nature, the oil adheres to the rotor, and if there is no obstruction between the periphery of the rotor and the surface which extends around it, the greater part of the accumulation of leakage oil will rotate with the rotor. If the space between the periphery of the rotor and the surrounding surface is gradually restricted through a limited angular distance, leakage oil will be driven into the restricted area and create therein a very substantial pressure which the present invention utilizes to remove leakage oil from the case of the machine and to raise it to a higher level.

As shown in Fig. 2, the inner periphery of slide block 6 is circular except the lower right hand portion thereof which includes a projection or shear 3l and a sloping surface 32. Shear 3l extends axially of slide block 6 and has its inner face arranged close to but not in contact with the periphery of rotor I5. Surface 32 slopes inward toward rotor I5 to form a progressively constricted area 33 and it terminates at shear 3| which may be Straight, as shown in Fig. l, or it may be of any other suitable shape such as in the shape of an open inverted V as shown in Fig. 3. Shear 3l and surface 32 have been shown integral with slide block 6 but they may be separately made and be attached to slide block 6.

Leakage oil is ejected from the space between side block 6 and rotor l5 through an opening 34 which is formed in slide block ii adjacent the under side of shear 3l and which has a slide pipe 35 fixed in the outer portion thereof. The outer end portion of slide pipe 35 is sldably fitted in a sleeve 36 which extends through the wall of case I and is connected by a pipe 31 to reservoir 29.

It has previously been explained that the greater part of the leakage cil tends to rotate with rotor I5. This movement of the oil with rotor I5 causes the oil to be packed into constricted area 33 and to create therein sufcient pressure to force oil through opening 34, slide pipe 35, sleeve 36 and pipe 3l into reservoir 29. Shear 3l removes the greater part of the oil from the periphery of rotor I5 and leaves only a thin lm of oil thereon.

The pump cylinders are thus kept filled with oil from an elevated tank and the leakage oil is returned to the elevated tank without the use of an auxiliary pump or other device.

Figures 3 and 4 The pump of which only portions are shown in these figures is the same as the pump shown in Figs. 1 and 2 except that the leakage oil is discharged through the bottom of pump case i instead of through the side wall thereof and the slide block 6 is providedV with an angular shear 3la instead of a straight shear 3| as in Figs. 1 and 2.

Due to the angular shape of the shear Sla, this pump has a sloping surface 32a which correspends to the surface 32 of Fig. 1 and is arranged between the arms of shear 3|a to form with the periphery of rotor I5 a constricted area 33a.

Leakage oil is ejected from restricted area 33*l through an opening 34a which extends downward case I.

Leakage oil is ejected from the slide block f of this pump in substantially the same manner as in the pump shown in Figs. l and 2.

That is, oil rotating with rotor I5 is crowded into constricted area 33EL and `creates therein sufficient:- pressure to force oil therefrom through opening 34a, hole 38, elbow 39 and pipe 31 to reservoir 29, and shear Sla removes all but a thin iilrn of the oil on the periphery of rotor I5.

Figure 5 The pump, a fragment of which is shown in this figure, is the same as the pump shown in Figs. 1 and 2 except that it has a constricted area 3313 formed by a sloping surface 32h, whichextends closer to the periphery of rotor I5 than does the sloping surface 32 of the pump shown in Figs. 1 and 2, and the angular edge on shear 3i is omitted. The other parts are the same as in Figs. 1 and 2 and are indicated by the same reference numerals. Leakage oil is removed in the same manner as in the pump shown in Figs. l and 2. If the upper portion of surface 32h is arranged very close to the periphery of rotor I5, it will act as a shear to remove nearly all of the oil thereto rotate in opposite directions alternately so that the means for removing leakage oil from the motor case must function regardless of the direction of rotation of the motor.

The motor shown includes a rotor I5, which is the same as the rotor I5 of the pump shown in Figs. l and 2, and a motor case 4I which encloses and rotatably supports rotor I5.

The inner periphery of motor case 4I is circular except that the lower central portion thereof where two oppositely inclined surfaces 42 and 43 are arranged upon opposite sides of the vertical center line of the motor and form, respectively, with the periphery of motor I5 two constrictved areas 44 and 45.

The two surfaces 42 and 43 slope upward and toward each other and each terminates atY or near the center line of the machine to provide between the two surfaces a face 46 which is close to but out of contact with the periphery of rotor I5.

Two openings 4l and 4B arranged upon opposite sides of and closev to the face 46 extend, respectively, through surfaces 42 and 43 downward into the base of motor case 4I and are connected, respectively, by passages 49 and 5D to two pipes 5I and 52 both of which lead to a tank such as tank 29.

When the motor` is operating, leakage oil will accumulate in the lower part of case 4I and the greater part of the leakage oil will tend to rotate with'rotor I5. If -rotor I-5rotatesina clockwise y direction as indicated by the arrow, the oil rotating with it will be crowded into restricted area 44 and create therein sucient pressure to force oil through opening 4l, passage 49 and pipe 5I to an elevated tank.

If rotor I5 rotates in a counterclockwise direction, the oil rotating with it will be crowded into constricted area and create therein sunicient pressure to force oil through opening 48, passage 50 and pipe 52 to4 an elevated tank. If face-46 is arranged very close to the periphery of rotor I5, it will remove all but a thin film of oil therefrom regardless of the direction of rotation so that the space beyond face 46 is substantially free of leakage oil.

The sloping surfaces and the projections or shears have been shown in the several views as being integral with the slide block or with the case but they may be made separate therefrom and then attached thereto.

Removal of oil from the pump or motor casestarts very nearly as soon as the accumulation of leakage oil becomes deep enough to touch the: lowermost part of the rotor and thereafter theoil is removed substantially as fast as it leaks. out of rotor. y

The oil under pressure in a constricted area exerts an upward force upon the rotor but the sloping surface extends through only a short angular distance so that the pressure area is not very large and the pressure created in the constricted area is only great enough to eject oil from the pump or motor case to an elevated tank so that the upward force exerted by the oil in the constricted area merely compensates for a part of the weight of the'rotor and thereby reduces the load on the rotor bearings.

The invention herein set forth may assume other forms and may be embodied in other machinos without departing from the scope of the invention which is hereby claimed as follows:

1. In a hydrodynamic machine having a rotor rotatable upon a horizontal axis and containing pistons and cylinders, valve means for controlling the flow of liquid to and from said cylinders, and a wall extending around said rotor and providing therebetween an annular chamber into which liquid leaking from said cylinders and said valve means will enter during operation of said machine and will at first accumulate in the lower part of said chamber so that rotation of said rotor will cause part of said leakage liquid to move with the periphery of said rotor, the combination of an obstruction extending the full length or said rotor and arranged upon a lower part of said wall with its inner face close to the periphery of said rotor to prevent movement past said obstruction ofthe greater part of the liquid moving with said rotor and thereby cause pressure to be created inthe liquid at one side of said obstruction in response to rotation of said rotor, and a channel extending rfrom said one side of said obstruction through said wall to provide a path through which liquid may be forced by said pressure.

2. In a hydrodynamic machine having a rotor rotatable upon a horizontal axis and containing pistons and cylinders, valve means for controlling the flow of liquid to and from said cylinders, and a wall extending around said rotor and providing therebetween an annular chamber into which liquid leaking from said cylinders and said valve -means will enter during operation of said machine and will at first accumulate in the lower part of said chamber so that rotation of said rotorwill cause part of said leakage liquid to move with.

. the periphery of said rotor, the combination of means carried by the lower part of said wall and cooperating with the periphery of said rotor to provide a gradually constricted space into which leakage liquid is forced by rotation of said rotor to create pressure in said space, and means through which said pressure may force liquid from said space to a point outside of said machine.

3. In a hydrodynamic machine having a rotor rotatable upon a horizontal axis and containing pistons and cylinders, valve means for controlling the ow of liquid to and from said cylinders, and a wall extending around said rotor and providing therebetween an annular chamber into which liquid leaking from said cylinders and said valve means will enter during operation of Vsaid machine and will at first accumulate in the lower part ci said chamber so that rotation of said rotor will cause part of said leakage liquid to move with the periphery of said rotor, the

' combination of means carried by the lower part of said wall and cooperating with the periphery of said rotor to provide a gradually constricted space into which leakage liquid is forced by rotation of said rotor to create pressure in said space, means for shearing liquid from the periphery of said rotor into said space, and means through which said pressure may force liquid from said space to a point outside of said machine.

4. In a hydrodynamic machine having a rotor rotatable upon a horizontal axis and containing pistons and cylinders, valve means for controlling the flow of liquid to and from said cylinders, and a wall extending around said rotor and providing therebetween an annular chamber into which liquid leaking from said cylinders and said valve means will enter during operation of said machine and will at rst accumulate in the lower part of said chamber so that rotation of said rotor will cause part of leakage liquid .to move with the periphery or" said rotor, the

:said space, and means for enabling said pressure to expel liquid from said space to a point outside of said machine including a channel extending from said space through said wall.

5. In a hydrodynamic machine having a rotor Arotatable upon a horizontal axis and containing pistons and cylinders, valve means for controlling -the flow of liquid to and from said cylinders, and :la wall extending around said rotor and providing Ytherebetween an annular chamber into which liquid leaking from said cylinders and said valve means will enter during operation of said ma- L.chine and will at rst accumulate in the lower part of said chamber sc that rotation of said rotor will cause part of said leakage liquid to move with the periphery of said rotor, the combination of a surface carried by the lower part of said wall and sloping toward the periphery of said rotor to provide a gradually constricted space into which leakage liquid is forced by rotation of said rotor to create pressure in said space, means for shearing liquid from the periphery of said rotor into said space, and means forrenabling said pressure to expel liquid from said space to a point outside of said machine rincluding a channel extending from said space through said wall.

6. In a hydrodynamic machine having a rotor rotatable upon a horizontal axis and containing pistons and cylinders, valve means for controlling the flow of liquid to and from said cylinders and a wall extending around said rotor and providing therebetween an annular chamber into which liquid leaking from said cylinders and said valve means will enter during operation of said machine and will at rst accumulate in the lower part of said chamber so that rotation of said rotor will cause part of said leakage liquid to move with the periphery of said rotor, the combination of a surface at least as long as said rotor carried by the lower part of said wall and sloping .toward the periphery of said rotor to provide a gradually constricted space into which leakage liquid is forced by rotation of said rotor to create pressure in said space, a shear arranged at the inner end of said surface to shear liquid from the periphery of said rotor into said space in response to rotation of said rotor, and means for enabling said pressure to expel liquid from said space to a point outside of said machine including a channel extending from said spac through said wall.

7. In a hydrodynamic machine having a rotor rotatable upon a horizontal axis and containing pistons and cylinders, valve means for controlling the flow of liquid to and from said cylinders and a wall extending around said rotor and providing therebetween an annular chamber into which liquid leaking from said cylinders and said valve means will enter during operation of said machine and will at rst accumulate in the lower part of said chamber so that rotation of said rotor will cause part of said leakage liquid to move with the periphery of said rotor, the combination of a surface carried by said wall and sloping toward the periphery of said rotor to provide a gradually constricted space into which leakage liquid is forced by rotation of said rotor to create pressure in said space, an angular shear arranged at the inner end of said surface with its face close to the periphery of said rotor to shear liquid therefrom into said space during rotation of said rotor and having two arms sloping from an intermediate point downward and toward the ends of said rotor, and means for enabling said pressure to expel liquid from said space to a point outside of said machine including a channel extending from said space through said wall.

8. In a hydrodynamic machine having a rotor, a displacement varying member enclosing said rotor and providing a space between its inner periphery and the outer periphery of said rotor, and a case enclosing said member and said rotor, the combination of means carried by said member and cooperating with the periphery of said rotor to provide a gradually constricted space into which leakage liquid is forced by rotation of said rotor to create pressure in said space, a channel extending from said space through said member to conduct liquid from said space, a channel extending through the wall of said case for conducting leakage liquid to a point outside lof said machine, and means providing a substantially iluid tight connection between said channels while permitting movement of said member within said case.

9. In a hydrodynamic machine having a rotor, a displacement varying member enclosing said rotor and providing a space between its inner periphery and the outer periphery of said rotor, and a case enclosing said member and said rotor,

the combination of a surface carried by said member and sloping toward the periphery of said rotor to provide a gradually constricted space into which leakage liquid is forced by rotation of said rotor to create pressure in said space, a channel extending from said space through said member to conduct liquid from said space, a channel extending through the wall of said case for conducting leakage liquid to a point outside of said machine, and means providing a substantially fluid tight connection between said channels while permitting movement of said member within said case.

10. In a hydrodynamic machine having a rotor, a displacement varying member enclosing said rotor and providing a space between its inner periphery and the outer periphery of said rotor, and a case enclosing said member and said rotor, the combination of a surface carried by said member and sloping toward the periphery of said rotor to provide a gradually constricted space into which leakage liquid is forced by rotation of said rotor to create pressure in said space, a shear arranged at the inner end of said surface to shear liquid from the periphery of said rotor into said space in response to rotation of said rotor, a channel extending from said space through said member to conduct liquid from said space, a channel extending through the wall of said case for conducting leakage liquid to a point outside of said machine, and means providing a substantially fluid tight connection between said channels while permitting movement of said member within said case.

1l. In a hydrodynamic machine having a rotor which is adapted to rotate in opposite directions alternately, the combination of a Wall extending around and spaced from the periphery of said rotor, two surfaces carried by said wall and sloping toward each other and toward said rotor to provide with the periphery of said rotor two gradually constricted spaces into one or the other of which leakage liquid is forced and pressure created in response to rotation of said rotor in one direction or the other, and a channel extending from each of said spaces through said wall to conduct liquid from the space containing liquid under pressure.

12. In a hydrodynamic machine having a rotor which isl adapted to rotate in opposite directions alternately, the combination of a wall extending around and spaced from the periphery of said rotor, two surfaces carried by said wall and sloping toward each other and toward said rotor to provide with the periphery of said rotor two gradually constricted spaces into one or the other of which leakage liquid is forced and pressure created in response to rotation of said rotor in one direction or the other, a shear arranged between the adjacent ends of said surfaces to shear liquid from the periphery of said rotor into the space into which liquid is forced in response to rotation of said rotor, and a channel extending from each of said spaces through said wall to conduct liquid from the space containing liquid under pressure.

JAMES K. DOUGLAS.

REFERENCES CITED .f The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 744,727 Dodge NOV. 24, 1903 1,061,142 Tesla May 6, 1913 1,313,700 King Aug. 19, 1919 2,074,068 Ferris Mar. 16, 1937 2,111,878 Tongeren Mar. 22, 1938 l2,164,888 Sassen July 4, 1939 2,220,636 Bischof Nov. 5, 1940 2,221,189 Hodge NOV. 12, 1940 2,285,754 Money June 9, 1942 2,386,459 Hautzenroeder Oct. 9, 1945 FOREIGN PATENTS Number Country Date 137,638 Great Britain 1920

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