US1621663A - Fluid-pressure motor - Google Patents

Description

'March 22, 1927. E' G GARTIN FLUID PRESSURE MOTOR Filed July 11, 1921 2 Sheets-Sheet 2 Patented Mar. 22, 1927.

UNETE@ STATES PA T ELMER Gr. GARTIN, OF CLAREMONT, NEVJ HAMPSHIRE, ASSIGNOR TO SULLIVAN MA- CHINERY COMPANY, A CORPORATION GF llIASSACHUSETTS.

FLUID-PRESSURE llOTOR.

Application filed July 11,

My invention relates to fluid pressure mo tors.

It has for its object to provide an improved fluid pressure motor. A further object of my invention is to provide an improved fluid pressure motor which is adapted to be constructed in relatively large sizes and at the same time prevent undesirable vibration. A still further object of my invention is to provide an improved fluid pressure motor preferably of the percussive type in which vibration resulting from checking the nomentum of the piston upon the return sti-oke may be reduced to a minimum. A. still further object of my invention is to provide an improved fluid pressure motor of the valveless percussive type in which improved cushioning means for the return stroke will be provided.

In the accoinpanying drawings I have shown, for purposes ot illustratiom' three forms which my invention may assume in practice.

In these drawings e Fig. l is a diagrammatic view of one form of my improved Construction, showing the piston about to begin its forward stroke, the View being taken substantially on the broken section line 1-1 of Fig. 6.

Fig. 2 is a similar view oi" the same form showing the parts with the piston at the opposite end of its stroke.

Fig. 3 is a diagrammatic View of another form of my improved construction, the pis-- ton being shown in the position corresponding to Fig. 1.

Fig. 4 is a similar View of this second form, .showing the piston at approximately the opposite end of its stroke.

Fig. 5 is a diagrammatic view of a third form which my invention may assume in practice.

Fig. 6 is a transvcrse section on the line 6-6 of Fig. 1.

In the embodiment of my improved motor shown in Figures 1, 2, and 6 the motor comprses a cylinder 1 in which there reciprocates a piston generally indicated by 2 and having a striking bar 3 cooperating in a well known manner with a drill steel not shown. The piston 2 consists of two heads 4 and 5 connected by a reduced portion 7 about which there is formed an annular g'roove 6. The piston is bored out internally to form a supplemental cylinder 10 co- 1921. Serial No. &83,778.

aXial with the piston and with this cylinder a projection or piston 11 attached to the rear head of the cylinder cooperates in a manner hereinafter described.

Fluid is distributed to the opposite ends of the cylinder l and controlled in a manner similar to a well known commercial type of motor. Live fluid is supplied through a fiuidpressure supply passage 12 which communcat'es at its forward end by means of a passage 13 of reduced area with a storage chamber 14, and the fluid pressure supply passage 12 and storage chamber 14': are respectively provided with ports 15 and 16 longitudinally separated from each other by a slight distance and opening into the bore of the cylinder near the center thereof. The supply of fluid to the o-pposite ends of the cylinder is controlled by the heads 4: and 5 and groove 6 of the piston, the groove 6 be- 7 ing adapted to alternately connect one or' both of the ports 15 and 16 with the opposite ends of the cylinder in a manner hereinatter described. The cylinder is likewise provided with suitable distribution passages 17 and 18 leading from points adjacent the middle of the cylinder to the opposite ends thereof the passage 17 being provided with two supply ports 19 and 20, of which 19 constitutes a starting port, and at its opposite 35 end communicating by means of a port 21 with the cylinder near its forward end. The passage 18 is provided with a supply port 22 and with a distribution port 23, the latter being located in the extreme rear end of ou the cylinder. Suitable eXhaust ports 8 and 9 are also provided and .so disposed as to be uncovered by the opposite ends of the piston at appropriate times.

Cooperating with the cylinder 10 formed :u in the piston andw'iththe projection 11 secured to the rear head of cylinder 1 is a supply passage 25 which extends centrally through the projection 11 and opens into the cylinder 10, this passage at its other o end being connected by means of a pair of ports 26 and 27 with the bore of the cylinder, the passage 26 being located in relatively the same cylinder belt as the port 22 and the passage 27 being located somewhat 'further forward in the cylinder. It will be understood that the parts 10, 11, and ports 25, 26 and 27 and their spacial arrangement, both ;er se and in combination with the remainder of the Construction, form a part of my improvement in the above mentioned well known commercial type of motor.

The operation of my improved motor is as follows: Starting with the parts in the position shown in Fig. 1, fluid pressure is being transmitted from the passage 12 by way of port 15 to the cylinder bore where it is directed by the groove 6 formed in the piston to the port 22- and thence by way of passage 18 and port 23 to the rear end of the cylinder where it acts on the annulus of the piston 2 surrounding the projection ll. Fluid pressure is smultaneously admitted by way of port 26 to passage 25, which conduots fluid into the cylinder chamber 10 in the piston 2, where it acts upon the forward end of this cylinder and supplements in eflect the pressure acting; on the rear end of the piston. Under the combined action of the motive fluid in the rear end of the cylinder l and the cylnder 10, the piston moves forward and at, or about mid-stroke, communication is closed between the port 15 and the port 22, after which further action of the pressure in the rear end of the cylinder 1 is expensive only. Substantially simultaneously with cut off in the rear end of the cylinder, fluid pressure is admitted from both fluid pressure supply passage 12 and from storage chamber 14, the latter of which was previously for a short time in communication with port 22, to port 19 and thence by way of passage 17 and port 21 to the front end of the cylinder. At about the moment when port 15 is closed, port is opened and live fiuid flows by way of port- 16 out of storage chamber 14, supplemented in part by the stored pressure ther-ein, and passes to the front end of the cylinder where it accumulates for the purpose of making a return st-rok-e, and where it acts, when suf ficient pressure has been built up, to partially cushion the extreme end of the forward stroke, the latter effect, however, being only negligible during drilling operation of the motor, but becoming effective when the motor is being run idly and is not actlng on a drill; at which time the stroke is, of course, considerably longer as it is checked only by the cushion. Just before the end of said stroke, the communication of port 27 with the fluid pressure supply is closed by its being overrun by the rear head of the piston. It will accordingly be noted that live fluid has acted for a considerably longer time, perhaps of the sti-oke, on the portion of the piston exposed to pressure in cylinder 10, whereby the power of the st-rolce is increased and an earlier, but light, cushioning eifect on the rear stroke will be accomplished. Upon the return stroke, it will be noted that the port 27 Will be opened very much earlier than is the port 22 and accordingly, as just stated, a much earlier partial cushioning efl'ect will be obtaincd, and even before the opening of the port 27 a cushioning effect to a lesser degree will be obtalned due to the ,fact that the fluid pressure in cylinder 10 was only partially expanded and will accordingly resist movement of the piston to some extent before live pressure is again admitted, this resistanc-e progressively increasing due to the compression of the pressure in the cylinder 10 until the moment when a pressure equal to that of live fluid will have again been reached. Throughout the remainder of the return S-POl-G, live pressure will continue to act in the cylinder 10 to cushion and mor-e near-ly equalize the velocity of movement of the return pass of the piston. As a result of this construction, it will be found that greater forward speed will oifset slightly reduced return speed and the vibration of the niotor due to the sudden stoppng of the motion of a relatively heavy piston moving at a relatively high velocity will be largely done away with. The location of the port 22, as a result of `this construction, may be changed, of course, somewhat from its position in the commercial Construction heretofore mentioned, this port being moved somewhat further to the rear end of the cylinder and accordngly the main cushioning action of the piston need not commence at quite so early a time in the stroke.

The modification shown in Fi'ures 3 and 4 isvery closely related in both function and structure to that shown in Figures 1 and 2, the Chief difference being that I have provided an eXhaust port for the purpose of permitting the escape of the fluid which has been actiug in the eylinder 10 therefrom at approxin'ately the forward limit of the piston stroke, the purpose of this eXhaust being to permit the starting of the piston on its return travel with no pressure acting to re- V sist its motion. In this Construction the passage 25' is made larger than was the passage' 25 for a considerable portion of its length and communicates with the cylinder bore l at three longitudinally separated points instead of at two. The ports 26' and 27' are located at substantially the same positions as were the ports 26 and 27, but an additional passage is provided which is so located as to be uncovered by the rear end of the piston head t at or preferably just after the momen! when the exhaust port for the rcar end of the cylindcr is uncovered. At this time the ports 26' and 27' are both closed and accordingl there is no loss of live fluid by direct passage from the inlet to the exhaust, but such fluid as is stored in the cylinoer 10 and in the various passages is free to pass out through the exhaust port. The passagjes 25 and 27 and the forward portion of the passage 25' which is for-med in the cylinder wall is of' less diameter than is lili) the remainderof the passage, this being for the purposes of controlling the fluid pressure supply Ioy the port areas of the connections 26' and 27' while providing ample area for the haust port.

The op tion is, in the general details of` fluid distribution to the opposite ends of the cylinder l, the same in the first form, but the cylinder lt) is exhausted at the forward end of the piston stroke and accordingly the initial motion ot the piston on its return Stroke is not cushioned and so a slightly quiclter start can be obtained.

In Figure 5 I have shown a still further form of my invention and one which is simpler than either of' those previously described. In this case the passage 27 is entirely omi ted and no exhaust port is provided tor the cylinder 10, the port 26" being closed substantially at the same time as the port 22. The operation inthis case is that the fluid entrapped in the chamber 10 at the moment of closure of port 26 acts expansively thei-ein during the remainder of the sti-oke and thereafter is recompressed up to initial pressure until the time when the port 26" is reopened. In this case I rely upon the recompression of the expanoled fluid to provide the equalization by the slight initial retardation of the piston, this construction, however, difl'ering from the previous-ly described Construction of Figures 3 and l in that, instead of exhausting and resupplying the fluid, I obtain the same low pressure effect in the beginning of the stroke by a considerable degree of expansion in the cntrapped fluid and thereafter recompress the same instead of readmitting a supply of fluid.

in all the forms of my invcntion herein shown for purposes of illustration, the common feature is the provision of means acting to accelerate the velocity during the forward strole and to slightly advance the beginning of cushioning on the return stroke whereby the piston does not acquire so extreme a veloeity toward the middle of its return stroke and according-ly such a great reaction upon the stopping of the piston at the end of the roke is not required. Accordingly., the (sc-.1118 e'flfect can be obtained in the matter of power and speed of operation by setting back the admission port for the rear end of the cylinder a slight distance toward the rear end of the cylinder and a relatively vibrationiess motor may be obtaned.

While I have in this application specifically described three forms which my invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration' and that the invention may be modified and embodied in other forms Without departng from its spirit or the scope of the appended claims.

ation of this form of my inven- What I claim as new and desire to secure by Letters Patent is:

1. In a fluid pressure drilling motor, the combination with, a cylinder, a piston therein, and means for dstributing fluid under pressure alternately to the opposite ends thereof and for exhausting used fluid, of fluid cushioning means controlled by said piston' for subjecting a portion thereof to fluid pressure resisting the rearward movement thereof, before the moment when the first mentioned fluid distributing means for the rear end of said cylinder is operative.

2. In a fluid pressure drilling motor, the combination with a cylinder a piston therein, and means for distributing fluid under pressure alternately to the opposite encls thereof and for exhausting used fluid, of fluid cushioning means cooperating with said piston for subjecting a portion thereof intermittently to fluid pressure for resistng rearward movement of said piston, before the moment when the first mentioned fluid distributing means for the rear end of said cylinder is operative.

3. In a fluid pressure drilling` motor, the combination, w'ith a cylinder, a piston reciprocable therein, and piston controlled means for distributing fluid pressure alternately to the front and rear ends of the cylinder and for the exhaust of used fluid therefrom, of fluid cushioning means for subjecting a portion of said piston to fluid pressure for substantially the entire rearward stroke of said piston to oppose rearward movement thereof. said piston controlled means being` operable independently of said latter means.

4. In a fluid pressure drilling motor, the combination with a cylinder, a piston reciprocable therein, and piston controlled means for distributing fluid pressure alternately to the front and rear ends of the cylinder and for the exhaust of used fluid therefrom, ,of fluid cushioning means for subjecting a portion of said piston to fluid pressure for substantially the entire rearward stroke of said piston to oppose rear-ward movement thereof, said meansbeing operative to provide a pressure less than the inlet pressure to resist return motion'of said piston at the beginning of the rearward pass of said piston.

5. In a fluid pressure drlling motor, the combination with a cylinder a piston therein, means for distributing fluid under pressure to the opposite ends thereof for a portion of the strokes in each direction, and means for eXhaust-ing used fluid, of fluid cushioning means comprising a projection fixed to one of said first mentioned elements and a cylinder formed in the other together with means for supplying fluid pressure thereto, said projection and cylinder always having a substantially non-leak fit, to control the velocity of the piston during the return stroke of the piston.

(3. In a fluid pressure drilling motor, a cylnder, a piston therem, means for distributing fluid under pressure to the opposite ends thereof for a portion of the strokes in each direction, means for exhausting used fluid, and means comprising a projection fixed to said cylinder and a cylnder formed insad piston together withmeans for supplying fluid pressure thereto, to control the velocity of the piston during the return stroke of the piston, fluid flow to said opposite ends being efl'ected independently of said latter fluid flow.

7. In a fluid pressure drillinp; motor, a cylinder, a piston thei-ein, means for distributing fluid under pressure alternately to the opposite ends thereof and exhausting used fluid therefrom, said distributing means heing operative to supply fluid to each end of said cylinder prio-r to the completion of the stroke toward that end, and means comprising a cylinder formed in one of said first mentioned elements and a projecton secured to the other thereof, together With means for periodically admitting fluid to said latter cylinder prior to the admission of fluid to the end of said first mentioned cylinder adjacent which said second mentioned cylinder and projection are arranged, Whereby to regulate the velocitv of the stroke toward that end of the cylinder.

8. In a fluid pressnre drilling motor, a cylinder, a piston reciprocahle therein, means for distributing' fluid under pressure to the opposite ends thereof and exhausting used fluid therefrom, and means controlled by the piston to admit intermittentlv fluid pressure to a portion of the piston during its rear- Ward movement.

9. (In a fluid pressure drilling motor, a eylinder, a piston recprocable therein, fluid supply means, piston controlled means for distrihuting' fluid pressure alternately to and from the rear ends of the cylinder and for the exhaust of used fluid therefrom, and means for subjecting a portion of said piston to fluid pressure for only substantially the entire rearWard stroke of said piston to oppose rearward movement thereot.

10. In a fluid pressure drilling motor. a cylnder, a piston reciprocable' therein, means for distributinn fluid under pressure to the opposite ends thereoi" and exhausting' used fluid therei rom. and means controlled by the piston to admit fluid within said piston during only a portion ot the cycle of movement of said piston to resist rearward movement and to assist forward movement of said piston. r

11. In a fluid pressure drilling motor a cylinder, a piston reciprocalole therein, fluid pressure distributing means to supply pressure alternatelv to the opposite ends ot the cylinder and to eXhaust used fluid therefrom and means arranged concentrically within the piston and separate from the fluid distributing means to control the velocity of said piston by exerting a varying :force on said piston.

12. In a fluid pressure drilling motor, a cylinder, a piston reciprocable therein, means 'for distributing fluid under pressure alternately to the opposite ends thereof and eX- hausting used fluid therefrom, said distributing means being operative to supply fluid to each end of said cylinder prior to the completion ox" the stroke toward that end, and means comprisng a cylinder having a bore ot' uniform dimensions formed in one of said first mentioned elements and a piston constituting memher Secured to the other thereot' and having a continuous running fit in said bore, a ported passage leading thereto and means controlled by said motor piston to close said port at a predetermined point in the travel of the piston.

13. In a fluid pressure drilling motor, a cylinder, a piston reciprocable thercin, an inlet port, means tor distributing fluid under pressure to the opposite ends of the cylinder and exhausting fluid therefrom, and means ?tor intermittently sulojecting a portion of the piston to fluid pressure resisting the rearward movement thereof before the instant When the first mentioned fluid distributing means for the rear end of said cylinder is operative. i

' 14. In a fluid pressure drilling motor, a cylinder, a piston reciprocable therein, fluid pressure means for cushioning the rearward stroke of said piston, and means for supplying actuating fluid to opposite ends of said piston operable independently of fluid flow to said other means.

15. ,in a fluid pressure drilling motor, a plurality of relatively small and large piston and cylinder elements, one of which is disposed at the rear of the other, means for supplying fluid to opposite ends of the larger cylinder. and means for supplying live pressure fluid intermittently to said smaller cylinder.

16. In a fluid pressure drilline motor` a plurality of relatively small and large piston and cylinder elements. one ot which is disposed at the rear end of the other, means for suppl vinz fluid to opposite ends of the larger cylinder. and means for supplying intermittently fluid under pressure above atmosphere to said smaller cylinder upon the rearward stroke of said piston.

17. In a fluid pressure drilling motor, a plurality of sets of piston and cvlinder elements, meansfwherebv fluid may be supplied to act on one of said pistons to eflect fluid cushioning of said other piston, and means for exhaustin said cushioning fluid.

18. In a flud pressure drilling motor, the combination With a cylinder and a piston recprocable therein having a cylindrical bore,

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of fluid eushioning means for said piston comprising a piston extending within said bore, and means 'or supplying fluid to said bore and exhausting it therefrom.

19. In a fluid pressure drlling motor, a cylinder, a piston reciprocable therein having a, cylindrical bore, a piston extending within said bore, and means for supplying fluid to said bore and exhausting it therefrom, said means including a. common passage.

20. In a, fluid pressure drilling` motor, a cylinder, a piston recprocable therein having a cylindrical bore, a. piston extending within said bore, and means for supplying fluid to said bore and exhausting it therefrom, said means including a common passage and branch passages.

21. In a fluid pressure drilling motor, a cylinder, e piston reciprocable thencin having a cylindrical bore, a piston ext'ending within said bore, and means for supplying fluid to said bore and exhausting it therefrom, said means including a common passage and branch passages adapted respectively to conduct live fluid and exhaust fluid.

22. In a fluid pressure drilling motor, a cylinder, a piston reciprocable therein having a cylindrical bore, a piston extending within said bore, and means for supplyng fluid to said bore and exhausting it therefrom, said means including a common passage controlled by said reciprocable pston.

In testimony whereof I afiix my signature.

ELMER G. GARTIN.

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