US2336847A - Fluid motor - Google Patents

Description

Dec. 1 4, 1943. N. M. coUTY J 2,336,847 FLUID MOTOR Filed Dec. 24, 1941 4 Sheets-Sheet l 5T.: fr

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a I28 k m ATTORY Dec. 14, 1943. N, M COU-ry v 2,336,847

FLUID MOTOR Filed Dec. 24, 1941 4 Sheets-Sheet 2 T 7 Z* `l *:UE

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Dec. I4, 1943. v -N, M COUTY' 2,336,847

FLUID MOTOR INVENTOR ATTORNY Dec. 14, 1943,

N. M. COUTY -FLUID MOTOR Filed Dec. 24, 1941v 4 Sheets-Sheet 4 INVENTOR ATTORNEY V Patented ec. 14, 1943 FLUID MOTOR Norman M. Couty, Ship Bottom, N. J., assignor to The Flex-O-Tube Qompany, a corporation of Delaware Application December 24, 1941, Serial No. 424,243

(Cl. 12l 151) 3 Claims.

This invention relates to uid motors and to a control system for regulating the reciprocation of the movable member of the motor by a reversing valve which is mechanically independent of the movable member but controlled in accordance with the position of said movable member.

It is an object of this invention to improve the art of duid pressure motors.

Another object of the invention is to control the reversing of the principal movable member of a iiuid pressure motor by a floating reversing Valve which is controlled in turn by the said principal movable member but is mechanically independent thereof.

A further object of the invention is to control the stopping of the motor by shutting off an exhaust passage to prevent a change of possession of the floating valve and thus to stop the principal movable member at one end of its travel in its cylinder.

Other objects, features and advantages will become apparent from the following description and appended claims.

For the purpose of illustrating the genus f the invention, a typical embodiment thereof is illustrated in the accompanying drawings in Figs. 1 to 6, inclusive, and the operation of the said illustrative embodiment of the invention is diagrammatically illustrated in Figs. 7 to 11 inclusive of the said drawings.

In the drawings:

Fig. 1 is a vertical longitudinal sectional view taken substantially along the line I I of Fig. 3 centrally through a hydraulic cylinder, a reversing valve cylinder and a discharge passage of a hydraulic cylinder body.

Figs. 2, 3, and 6 are transverse vertical sectional vlews through the hydraulic cylinder body taken substantially alo-ng the lines 2 2, 3 3, 5 5 and 6 5 of Fig. 1.

Fig. 4 is a horizontal longitudinal sectional view taken substantially along the line 3 4 of Fig. 2.

Figs. 7 to 11 inclusive are more or less diagrammatic Vertical sectional views of a theoretical embodiment of uid motors embodying the principle of the construction shown in Figs. 1 to 6 inclusive, and depicting especially the relationship of the power piston within its .cylinder with respect to its reversing valve in various operative positions of the iiuid motor.

Referring to the drawings, and rst-to Figs. 1, 2 and 3, a cylinder body I4 is provided with a cylinder bore I5 extending longitudinally of the body Ill, a reversing valve cylinder bore I6 and a pair of bores Il and ISiorming discharge and intake passages, respectively, the latter bores also being disposed axially parallel with the reversing valve bore I6 and the cylinder bore I5. A power piston -2 is disposed-in the hydraulic cylinder l5 for reciprocation therein and is provided with a piston shaft 2| which projects througha cylinder end bearing 22, a gasket element 23, and a packing nut 24 threaded to the cylinder body lli for maintaining the bearing 22 and gasket element 23 tightly assembled to the cylinder body I 4 to guide the piston shaft 2l and to prevent leakage by the said piston shaft 2l. The reversing valve 25 is disposed in itsl cylinder bore l5 and comprises fourr spaced pistons 25, 2l, 2B and i 29 which are made integral with or rigidly xed relative to a common shaft 35. The nut 3I is threaded to the cylinder body I4 at the open end of valve bore I6 for closing the latter. An annular valve guide 32 split along the line 33 is disposed in the valve bore I 6 about the valve shaft and is tightly maintained in the` position indicated in Fig. 1 by means of a set screw plug 3ft.

Referring also to Fig. 4, it is noted that the open ends of the discharge bore Il and of the intake bore I8 are threaded for the reception of standard pipe tting elements 35 and 35 for the discharge or return and supply of pressure uid from and to the motor. The tting 36 and associated conduit 39 .extend to any suitable source of fluid under pressure. As indicated in Figs. l, 2 and Ll, a pair of bores 3l and 38 extend downwardly from the top of the. cylinder body I 4 to the end of the hydraulic cylinder I5, thesek bores making an angle of approximately 69 degrees with respect to the axis of cylinder bore l5. The bores 31 and 38 extend through the intake bore I3 as indicated in Fig. 4, downwardly through the valve bore I6 to the ends of the hydraulic cylinder I5 as shown in Fig. l. With the reversing valve 25 in the position indicated in Fig. 1, the passage 38 is open through the valve "cylinder I5 between the pistons 28 and 29 of valve 25 While piston 26 of the valve 25 closes ,the bore 37 through the valve cylinder I5, but the lower end of the bore 3l is open between the power cylinder i5 and the Valve cylinder I3 permitting discharge of uid from the power cylinder through the valve cylinder I6.

When the valve 25 is at the other end of its cylinder I6, the left-hand end as viewed in Fig. 1 the piston 29 of valve 25 cuts oi the passage 33 through the cylinder I5 but leaves the lower end of the passage 33 open between power cylinder l5 and valve cylinder I6 while the bore 3l is open through the Valve cylinder I6 between the pisor the other of the center of travel of piston 22 so that the bore 4I will register with an annular groove 43 at the left-hand' end of piston 26 when the piston is in the right-hand position shown in Fig. 1, and so that the bore 42 will register with asimilar annular groove 44. at the right.- hand end of the piston 28 when thejlatter is at the limit ofits travel at Vthe left-handendof vthe hydraulic cylinder I5.

As indicated in Fig. 5, the annular groove 43 at the left-hand end of piston 22 not only registers with the intake bore 4| but also registers with a discharge bore 45 which leads from the hydrauliccylinder I5 to the discharge passage |1, but. the discharge bore 45 does not communicate with the reversing Vvalve I6.' As indicated in Fig. 4, a discharge bore 45, similar tothe bore 45 is Vprovided in the same transverse' plane with the intake bore`42 so asto register with the annular groove dat the right-hand Yend. of piston 2B when the latter is at its left-hand limit of travel within the hydraulic cylinder .l5 and the passage lit communicates between the hydraulic cylinder l5 and the discharge passage |11 withoutcom-k munication with the reversing valve cylinder l5. A needle valve 41 is threadedto the cylinder body |11 in axial alignment with -the bore 45 so as to close communication through such bore in order to prevent the reversing movement of thereversing valve and thereby stop operation of the piston 20 whenthe va1ve25 is at the. left-hand end of its lcylinder it and with the piston 20 in the positionl indicated in Fig. 1.:

Referring-now toiFigs. 1, 2 and 4, bores 5t and 5| are provided in thelcylinder body I4 and extend downwardlyin a vertical directionk from-the top thereof and communicate .between the discharge passage |1 and the left and right-hand ends of the reversing valve cylinder |5., The piston 29 ofV the. reversing valve 25` is adapted to close the passage 5| when the reversing valve 25 is in the position indicatedin Fig. 1.,. and. piston 2t. of the reversing valve 25 closes; the passage 5|) when thereversing valve 25 is at the lefthandY end of its cylinder I6. Plugs 52 threaded to theV cylinder body I4 close the upper ends ofY the bores 31, 38, III;l 42, 46', Eiland 5|. A small diameteredweep bore 53 leads from pistony shaft 2| through the bearing22 to an annular groove 54 in the periphery of the bearing 22, and this annular groove registers with a slightly inclined bore 55 which leads to the discharge bore 5|.

Figs. 1 to 11 inclusive diagrammatically depict a theoretical embodiment in which the various parts are given'nurnerals. 100 higher than the corresponding parts in the practical embodiment shown in Figs. i1 to 6 inclusive. Theoperation of the embodiment shown in Figs. 1 to 6. will be explainedV in connection with the diagrammatic illustration depicted in Figs.`7 to 11 inclusive.

VIn Figs. '1 to 11 inclusive, the intake passages |31, |38, |41 and |42 have associated therewith thearrows I indicating intakelpassages while the discharge passagesY If, |41, |5|and |58 have associated therewith the arrows D indicating discharge passages.- Figs. 1 and .'1 illustrate'the power piston |22 at the right-hand end of the'`r power cylinder ||5 with the angular groove |43 in the power piston brought into registry with the intake passage |4| and with the discharge passage |45. The needle valve |41 is assumed to be open at this time. The split bearing |32 for the reversing valve |25 not only serves as a bearing but also as a stationary partition interposed between the pistons |21 and |28 shown in Fig. 7. The provision of the annular groove at the lefthand end of the power piston allows relief of pressure within the chambers lying between the piston |21 and the split bearing |32 while the intake passage |42 is cut oir by the power piston so that at this time no pressure relief is aiiorded within thechamber lying between the split bearing' |32 and the piston |28. This causes the reversing valve |25 to be moved to the right-hand position indicated in Fig. .'1 since any pressure in the chamber lying between the piston |26 and |21 would impress equal forces on opposed end faces of such pistons and would thus counterbalance each other while the same conditions would exist in any chamber provided between the pistons |28 and |29.

When pressure is relieved in the chamber to the left of the split bearing |32, the chamber immediately to the right of such split bearing would force the reversing valve |25 to the righthand position shown. With the parts in this position, the intake passage |38 is open to the right-hand end of the power cylinder i i5 to move the power piston |26 to the left, the piston |253 of the'reversing valve |25 cutting olii the passage |5| to prevent discharge from the right-hand end of the power cylinder. The piston |26 of the reversing valve at this time cuts oir the upper end of the intake passage |31 and the reversing valve cylinder, but the lower end of the passage |31 is open between the left-hand end of the power cylinder, and the left-hand end of the reversing valve cylinder permitting discharge from the power cylinder ||5 to the discharge passage |52 to relieve pressure to the left of the power cylinder |28 during the left-hand stroke of the power piston. l

As indicated in Fig. 8 the reversing valve |25 remains at rest during the left-hand stroke of the power piston since both intake passages mi and M2 are out ofiV by the. piston |23 so that pressure within the chambers to the right or left of the split bearing |52 equalize each other while pressures within the chambers between the pistons |26 and |21 or between the pistons |23 and |29 exert equal forces on opposed piston end faces so that there is no tendency to dislodge the reversing valve |25 from the position indicated in Fig. 7 or 8.

When the power piston |26 arrives at the lefthand end of the hydraulic cylinder as indicated in Fig. 9, the annular groove IM at the righthand end of piston |20 registerswith the intake passage |42 at discharge passage l-4 relieving pressure within they chamber between the split bearing |32 and piston |23v while the intake passage is cut oi by the.Y power piston 2li/so that the chamber immediately.` to the left of theV split bearing |32 maintains its ypressure 'tofforce the reversing valve |25. to the letti-hand 'end of its cylinder IIB to the vposition indicated'in Fig. 10.

With the reversingvalve V|25 in'the position shown in Fig. 10, the intake" passage 2131; admits pressure fluid tor the `lef'tof the power piston |23 since-the pistonljt no longer cuts Voil the intake passage |31;but rather 'does cutoi the 'dischargel passar-e150 tolprevent relief of pressurey at the left-hand end of the power cylinder, while at the same time the piston |29 of reversing valve |25 cuts off the intake passage 33 at cylinder i le but permits passage through the lower end of the bore |38 and communication between the righthand end of the power cylinder and the discharge passage |5| to the right-hand end of the reversing valve cylinder H5 relieving pressure to the right of the power piston |29. This causes righthand movement of the piston |23 as indicated in Fig. 1l. As the power piston |25 moves from the position indicated in Fig. 10 to the position shown in Fig. 11, so the po-wer cylinder |25 cuts off both intake passages Ml and |132 thus equalizing pressure within the chambers to the right and left of the split bearing |32 while pressure within the chambers lying between pistons |26 and |21 and between pistons |28 and |29 apply to equal areas and opposed faces of such pistons and thus counterbalance each other. This permits the valve |25 to remain in the position shown in Fig. l1 until the annular groove |43 again registers with the intake passage 14| to cause a reversal of the valve |25 to the position indicated in Fig. '7.

If at any time the needle valve |41 of the embodiment shown in Figs. '7 to 11 is screwed down to its seat closing the discharge passage |135, operation of the motor can continue only until the reversing valve |25 reaches the left-hand position as indicated in Fig. 11 and the power piston I2@ moves to the right-hand end ofthe power cylinder H5, the position of the power pistons in Figs. 1 and 7, at which time the annular groove |43 of Fig. 11 could no longer relieve the pressure in the chamber immediately to the left of the split bearing |32 so that the reversing valve |25 could not be moved to the right and operation of the motor woul-d stop. Speed control may be obtained by throttling the intake flow.

As many changes may be made in the above indicated construction, and many apparently widely different embodiments of this invention could be had without departing from the spirit and scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as il lustrative and not in a limiting sense.

What is claimed is:

1. In combination with a hydraulic cylinder, y

a power piston therein, means for introducing fluid under pressure selectively upon either side of said power piston, said means comprising a source of pressure fluid and members defining passages from said source of pressure fluid to points within said cylinder on either side of said power piston, valve means comprising a cylinder and a pair of spaced pistons for alternately opening one and closing another of said passages, a pair of passages leading from said source to said valve cylinder and to the cylinder for said power piston independently of the first mentioned passages, said valve means including a second pair of spaced pistons, and a stationary partition disposed in said valve cylinder intermediate said last-named pistons on said valve forseparating said pair of passages one from another, said pair of passages being so arranged that said power piston at each limit of its travel opens one of such passages while keeping the other passage closed to cause pressure iiuid impressed on the valve and on said partition by said first passage to operate the valve and reverse the direction of travel of the power piston.

2. In combination with a hydraulic cylinder, a power piston therein, means for introducing fiuid under pressure selectively upon either side of piston, said means comprising a source of pressure fluid ,and members defining passages from said source of pressure fluid to points within. said cylinder on either side of said power piston, valve means comprising a shaft and a pair of spaced pistons one xed to each end of said valve shaft, a second pair of pistons fixed in spaced relation on said valve shaft intermediate said first-named pistons, said first-named pair of pistons being arranged for alternately opening one and closing another of said passages, a valve cylinder for said valve means, a split bearing arranged within said valve cylinder about said valve shaft and fixed to the cylinder intermediate the second-named pair of pistons fixed to the valve shaft, and a pair of passages leading from said source to the valve cylinder and to said power piston, said split bearing separating passages of said pair within the valve cylinder, said pair of passages being so arranged that said power piston at each limit of its travel opens one of said pair of passages while keeping the other closed to cause pressure fluid impressed on the valve and on said split bearing from said closed passage to operate the valve and reverse the direction of travel of the power piston.

3. In combination with a hydraulic cylinder, a power piston therein, means for introducing fluid under pressure selectively upon either side of said piston, said means comprising a source of pressure fluid and members defining passages from said source of pressure fluid to points within said cylinder on either side of said power piston, valve means comprising a shaft and a pair of spaced pistons one fixed to each end of said valve shaft, a second pair of pistons fixed, in

spaced relation on said valve shaft intermediate said first-named pistons, said first-named pair of pistons being arranged for alternately opening one and closing another of said passages, a valve cylinder for said valve means, a split bearing arranged within said valve cylinder about said valve shaft and xed to the cylinder intermediate the second-named pair of pistons fixed to the valve shaft, a pair of passages leading from said source to the valve cylinder and to said power piston, said split bearing separating passages of said pair within the valve cylinder, said pairof passages being so arranged that said power piston at each limit of its travel opens one 0f said pair of passages while keeping the other closed to cause pressure fluid impressed o-n the valve and on said split bearing from said closed passage to operate the valve and reverse the direction of travel of the power piston, and other means for closing one passage of said pair of passages to stop operation of said piston.

NORMAN M. CQUTY.

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