US2125452A

US2125452A - Hydraulic motor

Info

Publication number: US2125452A
Application number: US714923A
Authority: US
Inventors: Robert C Lamond
Original assignee: American Engineering Co Ltd
Current assignee: American Engineering Co Ltd
Priority date: 1934-03-10
Filing date: 1934-03-10
Publication date: 1938-08-02
Anticipated expiration: 1955-08-02

Description

Aug. 2, 1938. R. c. LAMoND HYDRAULIC MOTOR Fi1`d lawn 1o, 1934 2 Sheets-Sheet 2 A w/l Ww. In!

u Aam@ Patented Atag-193s PATENT ori-ICE alzsasz 'HYDRAULIC Moron.

Robert c. ramada; Philadelphia, ra., assigner io American Engineering Company, Philadelphia,

Pa., a corporation of Pennsylvania Application March 10, 1934, Serial No. 714,923

14 Claims.

This invention relates to Yhydraulic motors, and more particularly to hydraullcmotors of the reeiprocating plunger type adapted for use in steering: mechanisms.

One object of the present invention is to provide a generally improved valve mechanism for iluid motors of the stated character which functions to bypass fluid from the pressure side of the motor to the exhaust side thereof when the ram approaches its limit of travel in either direction. l

Another object is to provide a uid motor of the stated character having associated therewith a. valve unit enclosed Within a suitable casing and operatively connected to` a driven member, and so constituted as to bypass iiuid from the pressure side of the motor to the exhaust side thereof when the latter approaches its limit of travel in either direction, and to prevent a reverse ow offluid when the pressure at both sides of the motor becomes substantially balanced. J

Other and further objects will become apparent as the description of the invention progresses.

Of the drawings:

Fig. 1 is a plan View of the assembled construction including the valve unit comprising the present invention.

Fig. 2 is a plan. View partly in section of the valve unit and the operating mechanism therefor.V M i l Fig. r31s a sectional elevational view takensub-` stantially along'l line 3--3 oi' Fig. 2.

. Fig. 4 is a-plan View showing the valve unitk applied to a fluid motor of the single ram type.

Referring to the drawings, the numeral I designates generally a fluid motor comprising aligned pairs of cylinders2, 3 and A, 5 having rams 6 and l, respectively, operating therein'. Motor I is actuated by a variable stroke reversible discharge pump 8 driven by any suitable power means, such,v,for example, as an electric motor 9. Pump t is of the general type shown and described in theUnited yStates patent` to Hele- Shaw No. 1,077,979, to which reference may be had for a' full disclosure thereof. Rams 6 and having valve chambers I8 and I9 provided at the opposite ends thereof, connected by a communieating passage 20. Communicating with chambers I8 and IS are a pair of passages 20 and 2| provided in

extensions

22 and 23 respectively, of casing I1. The outer ends of

extensions

22 and 23 are provided with

anges

24 and 25 to which are bolted companion flanges `24 and 25' which secure pipes I 2 and I4, respectively, to casing I1.

Referring vto Fig. 3,

extensions

22 and 23 are provided with

vertical passages

21 and 28 respectively, extending upwardly from passages 20 and 2|. The upper ends of extensions v22 and 23terminate in'ilanges 29 and 30fto which are bolted companion flanges 3| and 32 which secure pipes I3 and I5 respectively to casing I1.

1 A pair of `

valves

33 and 34 engage valve seats provided at lthe inner ends cf passages 2o and -2I, respectively, and are normally held in seated position by springs and 36. The stems 31 and 38 of

valves

33 and 34 extend through glands 39 I and 40 respectively, and the outer ends of which are provided with slots 4i and 42 which respectively receive

pins

43 and 44 provided at the opposite ends of a lever 45. Lever`45 is pivoted intermediate its ends at 46 to'an extension 41 of casing l1. A projection 48 extends outwardly, from lever and is adapted to be engaged by bolts 49 and 50 adjustably mounted in a pair oi' ears 5I and 52, respectively, projecting outwardly at spaced points from rudder stock Ill. Bolts 49 and'50 are so positioned that when the rudder stock Ill has been operated a predetermined amount-in one direction bolt 49 will engage projection 43 to open valve 33 and when operated a. predetermined distance in the reverse direction bolt 50 will engage projection 48 to open valve 34. As shown in Fig. 2, the diameters of

pins

43 and 44 are slightly less than the width oi slots` 4l and 42 to enable tilting of lever 45 about its pivot 46.

As shown in Fig. 2, casing I'l oi valve unit I3 'is provided with an intermediate chamber 53,

and a passage 54 establishes communication between said chamber and communicating passage 20'; A relief valve 53 normally engages a valve seat provided at the inner end of passage 54 and thereby normally prevents the passage of fluid from passage 2n' to chamber 63.. Valve 55 is normally held in closed position by a coll spring 56 which extends between the latter and an adjustable spring seat l1. An adjustable bolt Il this construction it is seen that the tension of spring 56 may vbe regulated by simply adjusting b olt 58. Fluid entering chamber 53 is discharged into a makeup tank |00 for the system through an aperture 6I provided at the bottom of said chamber and a pipe 62. f

From this construction it is seen that if pump 8 is so adjusted as to deliver uid pressure to pipe I2, and suction to pipe I4, the pressure of this fluid acting against the inner end of valve 33 will actuate the same to the left (Fig. 2) against the. tension of spring `35. Fluide/may then pass through communicating passage 20' and-into chamber I9. This pressure then acts against the annular shoulder 63 provided on value 34, thereby tending to retain the same upon its seat. It is also seen that if pump 8 is adjusted so as to deliver iiuid pressure to pipe I4, valve 34 will be actuated te the left against the tension of spring 35, thereby permitting iiuld to enter chamber I8` through communicating passage 20'. 'I'he pressure acting against the annular shoinder 64 4provided on valve 33 retains the latter upon its seat. It is also seen that during operation of the device, in the event that the pressure in passage 20' shouid exceed the tension of spring 56, vvalve 55 will be moved to the-right (Fig. 2), thereby permitting fiuid to ow from passage 2li into chamber 53 and thence to exhaust through pipe 52. By this construction excessive pressures in the system are prevented.

Referring to Figs. 1 and 2, it willl be observed that when pump 8 has been adjusted to deliver fluid pressure to pipe I2, fluid under 'pressure willenter cylinders 2 and 5 thereby causing rams 6 and l to operate crosshead II and rudder stock III in a. clockwise direction. As the rams and rudder stock approach the limit of their travel the inner end of bolt 50 will engage projection 48 on lever 45, thereby actuating valve 341 to the left against the tension of spring 36, and also against the pressure of the fluid acting on shoulder 63, thus establishing communication between pipes I2 and I4. Fluid under pressure then also enters cylinders 3 and 4 with the result that the pressure on both sides of the mote-r soon becomes balanced or equalized, thereby eecting a cushioning action on the ramsA and stoppage thereof from further travel. 'At this time rpump 8 has been adjusted to neutral position. Mechanisms for adjusting pumps in this manner are well isnown in the art, and for a full disclosure of such a mechanism, reference may be had to mg United States Patent No. 1,986,640. Spring 35 will now urge valve 33 into engagement with its seal and thereby prevent a reverse flow of fluid in the system. Now upon reversal of the discharge of pump 8 iluid under pressure will enter cylinders 3 and 4 causing rams 6 and 'I to operate cross-A head Ii and rudder stock Ill in a counter clocl-r-Y wise direction.- 'I'his movement continues untii the inner end cf bolt 49 engages projection 48 thereby causing valve 33 to move to the left, and

and 34 may be urged to closed position in the manner described aboveowing to the lost motion provided by virtue of the pin .and slot connection -between said valves-andlev.er45.` y

Figs. Zand 3, is connected to pipes i4', i5

and 16', 'il' and a pair of adjustable bolts 49 and .5' provided in rudder stock I0' are adapted to engage projection t8' provided on a lever 45', associated with-said vaive unit when the said rudder stock is actuated toward its limiting positions by ram 12. By this construction it is apparent that when ram 12' is actuated in either direction, upon approaching its limit of travel,.

bolt 49 or 50 will actuate the valves of unit I6 toeiect bypassing of the iiuid between the cylinders. This action obviously produces a cushioning effect upon the ram and prevents damage to the parts. v

While the embodiments herein shown are admirably adapted to fulll the objects primarily stated it is to be understood that the invention is not to be limited to the embodiments herein shown as it may be embodied in other forms, all coming within the scope ofclaims which fol- 10W.

What is claimed is:

l. In a device of the class described, the combination with a uid meter, of a pump for actuating said motor, said motor comprising a pair of aligned'cylinders and a ram operative in said cylinders, a rudder stock operatively connected to said ram, norm-ally inoperative bypass means connecting said cylinders, and means provided on said rudder stock for actuating said by-pass means to render the latter operative when said rudder stock approaches its limit of travel in either direction.

2. In a device of the class described, the combination with a uid motor, of a pump for actuating said motor, said motor comprising a pair of aligned cylinders, and a ram operative in said cylinders, a rudder stock operatively connected to said ram and adapted to be adjusted upon movement of said ram in either direction, bypass means disposed between trie cylinders of said motor, and means provided on said rudder stock for actuating said bypass means when the rudder stock approaches its limit of travel in either direction to thereby equalize the pressure in said cylinders.

3. in a device'of the class described, the ccmbination with a iiuid motor, comprising a pair of aligned cylinders, and a ram operative in said cylinders, of a pump for actuating said motor, a rudder stock operatively connected to said ram, bypass means, piping connectingy said bypass means with said cylinders, norma'Jy closed valves in said bypass means, said valves `being so disposed that Awhen one of said cylinders is subjeeted to pressure one of said valves'ls opened, while the other is held in closed position, and when the other of said cylinders i's subjected to pressure said last mentioned valve is epened, and said rst mentioned valve is held in closed position, operating means for said valves, and means provided on said rudder stock foractuating said operating inders whereby pressure may be applied to either of said cylinders while exhausting the other, by-

pass means connected to said piping having normally closed valves provided therein, saidvalves being so disposed that when one of said cylinders ,is subjected to pressure one of said valves is opened, while the other is held in closed position, and when theother of saidcylinders -is subjected to pressure said last mentioned valve is opened,

and `said rst mentioned valve is held in closed position, of a rudder stock'operatively connected to said ram, operating means mounted on said rudder stock, and means operated by said last mentionedlmeans when the rudder stock approaches its limit of travel ,onl one direction to open one of said valves held in closed position,

and to open the other of said valves held in closedl position whenapproaching its limit of travel in the reverse direction.

5. In a device of the class described, the combinationr with a iiuid motor' comprising a ram, and a pair of cylinders embracing the opposite ends of said ram, of means for applying uid pressure to either of said cylinders while. exhausting the other, a rudder stock operatively connected -to said ram, bypass means between said cylinders comprising a casing, a pair of normally closed valves provided in said casing, a communicating passage betweensaid valves, said valves being so' disposed vthat when one o! said cylinders -is subjected to pressure one oi said valves is opened, while the other4 is heldin closed position, and when the other-oi! said cylinders is subjected to pressure, said last mentioned valve is opened, and said first mentioned valvel is held in closed position, a relief valve connecting said communicating passage to exhaust, a common operating member for said first mentioned valves, means mounted on said rudder stock for actuating said operating member to open one of said valves held in closed position when the ram approaches its limit o! travel in one direction, and, additional means mounted on said rudder stock for actuating said operating member to open the other of said valves held in closed position when the ram approaches its limit oi travel in the reverse direction.

6. In a device of the class described, the combination with a fluid motor, comprising a ram, and a pair of cylinders embracing 'the opposite ends of said ram, of a pump, piping connecting said pump with said cylinders whereby pressure may be applied to either of said cylinders while exhausting the other, bypass means connected.

in closed position by the pressure from said pump '-whenthe ram approaches its limit oi' travel to thereby equalize the pressure in said cylinders,

and means for normailyholding said valves in closed position.

7. In a'device oi'the' class described, the coml bination of a. iiuid motor, comprising a ram, a

pair of cylinders embracing the opposite ends of said ram, of a pump. Piping connecting said pump with said cylinders whereby pressure may b applied to one of said cylinders while exhausting the other, a rudder stock operatively connected to said ram, bypass means connected to said piping, normally closed valves in said bypass means, one of said valves controlling the flow oi.' uid from the cylinder subjected to pressure to the cylinder connected to exhaust, when said ram is moved in one direction, the other of said valves controlling the ow of fluid from the cylinder vsubjected to pressure to the cylinder connected to exhaust when the ram is actuated in the reverse direction, said valves being so disposed that when one of said cylinders is subjected to pressure one of said valves is opened, while the other is held in closed position, and when the other of said cylinders is subjected to pressure said last mentioned valve is openedfand saidilrst mentioned valve is held in closed position, a common operating member for said valves, means provided on said rudder stock for actuating said member to open one of said valves held in closed position when said rudder stock'approaches its limit of travel in one direction, and additional means on said rudder stock for actuating said member to open the other of said valves held in closed position when said rudder stock approaches its limit of travel in the reverse direction. 1

8. In a device of the class described, the combination with a fluid motor, comprising a pair of rams, cylinders embracing the opposite ends of each of said rams, of means for applying fluid subjected to pressure to the cylinders connected to exhaust when the rams are actuated in one direction, the other of said valves controlling the ilow of iluid from the cylinder subjected to pressure to the cylinder connected toexhaust when the rams are actuated in the reverse direction,v

said valves being so disposed that when one o!` said connected pairs oicylinders issubjected to pressure one of said valves is opened, while the .Other is' held in closed position, and when the other of said connected pairs oi.' cylinders is subjected to pressure said last mentioned valve is opened and said first mentioned valve is heldin closed position, a common operating member for said valves, a rudder stock operated by said rams, means providedon said rudder stock for actuating said member to openone of said valves held in closed position when said rudder stock ap' proaches its limit' of travel in one direction, and additional Qmeans on said rudder stock for actu-v ating said member to open the other of said valves held in closed position when said rudder stock approaches its limit of travel in the reverse direction: v

9L In a device of the class .bination of a duid motcr, comprisinga ram, and

a 4pair of cylinders embracing the opposite ends.

described, the comof said ram, of means for applying duid pressure to either of said cylinders while exhausting the other, bypass means between said cylinders comprising a casing, a pair of normally closed valves provided in said casing, ai communicating passage between said valves, saidvalves being so disposed that when one of said cylinders is subiected to pressure one of said valves is opened,

while the other is held in closed position, and

wheny the other of said cylinders is subjected to pressure said last mentioned valve is opened,` and said-first mentioned valve is held in closed position, a relief valve connecting said communicating passage to exhaust, a common operating member for said rst mentioned valves, adjustable means for actuating said operating member to open one of said valves held in closed position when the ram approaches its limit of travel in c one direction, and a second adjustable means for actuating said operating member to open the other of said valves held in closed position when the s ram approaches its limit of travel in the reverse direction, and resilient means for urging the valve opened by the application of fluid pressure to closed position when the pressure at both ends of said rdm becomes substantially balanced.

10. In a device of the class described. the combination withv a fluid motor, comprising a ram, a pair of cylinders embracing the opposite ends of said ram, of a pump, piping connecting said y pump with said cylinders whereby vpressure may be applied to either .of said cylinders while' exhausting the other, a rudder stock operatively connected to said ram, bypass means connected to .said piping, normally closed valves in said bypass means, one' of said valves controlling the flow of uid from the cylinder subjected to pressure to the cylinder connected to exhaust when said ram is moved in one direction, the other' of `said valves controlling the flow of iluid to the justab'le means provided,l on said rudder stockior actuating said member to` open one of said valves held ina closed position when said rudder stock approaches its limit of travel in one direction, and a second adjustable means on said rudder stock for actuating saidvmember to open the other of said valves held in 'closed position when said ram approaches its limit of travel in vthe reverse direction.

1l. In a device of the class described, the combination with auid motor' comprising a ram, and a pair of cylindersembracing the opposite ends of said ram, of means forl applying fluid pressure to either of said cylinders while exhaust ing the other, bypass means between said cylopened, while the other is held in closed position, and when the other of said cylinders is subjected to pressure said'last mentioned valve is opened. and said first mentioned valve is held in'clOSd position, a common operating member orsaid valves, means for actuating said-member to open theyvalve held in closed position when the ram approaches its limit of" travel in one direction to thereby balance the pressures at each side of said motor, spring means for urging the` valve held in open position by the application of uid pressure to closed position when the pressure at each side of said motor becomes substantially balanced, and a second means for actuating said' member to open the other of said valves held in closed position when`the ram approaches its limit of travel in the reverse direction to again balance the pressures at each side of said motor, and resilient means for urging the other of said valves held in open position by the application o f iiuid pressure to closed position when the pressure at both `sides of said motor again becomes substantially balanced.

12. In a device of the class described, the combination with a fluid motor comprising a pair of rams,- and cylinders embracing the opposite ends of each of said rams, of means for applying fluid pressure to said cylinders, piping connecting the cylinders of one ram with the diagonally opposite cylinders or the'other ram whereby pressure may be simultaneously applied by said means to either `of said connected pairs of cylinders while f exhausting the other, bypass means between said connected .pairs of cylinders comprising a casing, a pairl of normally closed valves provided in paid casing, and a communicating passage between said valves, said valves being so disposed that when one of said connected pairs of cylinders is subjected to pressure one of said valves is opened whilel the other is held in closed position, and when the other of said connected pairs, of cylinders is subjected 4to pressure said last mentioned valvel is opened 'and said first mentioned valve is heldin closed position, a common operating member for said valves, means for actuating said member to open the valve held in closed position when the rams approach their l when the rams approach their limit of travel'in the reverse direction to again balance the pressures at. each side ofl said motor, and resilient means for urging the other of said valves held in open position by the application of pressure to s pressure to' either of said cylinders while exhausting the other, bypass means between said cylinders comprising a casing, a pair of normaliy closed valves provided in said casing, and

a communicating passage between said valves` said valves being so disposed that when one ci said cylinders is subjected to pressure one of said valves is opened, while the other is heldin closed position, and when the other of said cylinders is subjected to pressure said last mentioned valve is opened, and said iirst mentioned valve is held in closed position, a commonoperating memberfor said. valves, means for actuating said A Y member to open one of said valves held in closed position when the ram approaches its limit of travel in one direction to thereby balance the pressures at each side of said motor, a. second means for actuating said member to open the other of said valves held in closed position when the ram approaches its limit of travel in the reverse direction to again balance the pressures at each side of said motor, and means providing la lost motion connection between said member rams, and cylinders embracing the opposite ends of said rams, of means .for applying duid presj sure to said cylinders, piping connecting the cylinders ci one ram with the diagonally opposite cylinders of the other ram whereby pressure may be simultaneously applied by said means to eitherv of said connected pairs of cylinders while exhausting the other, bypass means between said connected pairs of cylinders comprising a casing, a pair of normally closed valves provided in yinders is subjected to pressure one of said valves is opened, while the other is held in closed posi tion, and when the other of said connected pairs of cylinders is subjected to pressure said last mentioned valve is opened and said iirst mentioned valve is held in closed position, a common operating member for said valves, means i'or actuating said member to open one of said valves held in closed position when the rams approach their limit of travel in one direction to thereby balance the pressures at each side of said motor, a second means for actuating said member to open the other of said valves held in closed position when the rams approach their limit of travel in the reverse direction to again balance the pressures at each side ci! said motor, and means providing a lost motion connection between said member and said valves to permit relative movement of said valves..

ROBERT C. LAMOND.