PISTON PUMP AND PISTON PUMP AND MOTOR ASSEMBLY

Abstract: The present invention refers to a piston pump and motor assembly, of the type comprising a piston pump unit and a piston motor unit coupled in a closed hydraulic circuit, each one of the said pump and motor units having at least one double action piston, and comprising driving means (2, 3, 4, 54, 58, 63) for receiving an input power, at least one first pair of crank arms (21, 81) rotatively driven by the said driving means (2, 3, 4, 54, 58, 63), at least one second pair of crank arms (28, 84) coupled to at least one movable driven shaft (26, 86), at least one pair of crank arms (25, 85) coupling in an intercrossed manner the said first and second pairs of crank arms (21, 28, 81, 84), connecting means (29, 30, 32, 90) coupling the said movable driven shaft (26, 86) to at least one piston (33, 89) of the said pump unit, whereby upon each rotation of the said driving means the said pistons carry out four strokes of hydraulic fluid volumetric displacement, means (42) for directioning the said displaced hydraulic fluid for actuating the said driving means, cam means (9, 10, 66) integral with the said driving means (3, 54, 58, 63) and cam follower means (13, 68, 72) coupled to each piston of the said motor unit, whereby the said pistons of the motor unit cause a hydraulic fluid displacement which is reinforced by the said pistons of the pump unit.

Description: "PISTON PUMP AND PISTON PUMP AND MOTOR ASSEMBLY" BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to h dr ul ic syste and, wore specifically, to a piston PUMP an to a piston P and Motor assembly particularl suitable to be used in t driving of working units. Prior Art Several t es a Models of draul ic PUMPS a widely known from the st te of the art, which are used in a and all types of hyd aul ic systems. Generall speaking, the pumps can be defined as b ing one of the basic elements of the h draul ic systems, t gether with valves. Motors, connections, tubings and other a d their M i objective is to convert electrical, mechanic or even hy rauli energ received fro* a Motor into dyn m h draulic ener y. The hydraul ic pumps presently own can be divid or classified in five main es or groups, acco ding to i operative principle, namel reciprocating pumps, gear pump bl de PUMPS, piston p mps an cent if gal pumps. The reciprocati g or lternati g movement h raul i pumps have a Major dis ant ge in th the same do n produce a continuous flow of hydraul i energy, which preven their util isation in h raul ic s stems where a continuous fl is eeded. The gear t e hydraul ic PUMPS are capable of produc i ng continuous flow, with flow rates of app o' i tnate1 y 80 1/ιtιin at pressures of 120 kg/cm . However, the main problem with thi ty of ump is hei low effi ie c , z , n e a m jor part of the e eiv d po er i = use to move i t r e rs nd o !'., a small portion of th t power ιr use to gener te er y. The bl de ty e pumps- hile being capable of pro uc¬ ing flow rates similar to those of the gear um with let ¬ ter efficiency, present the problem of being of co ple . construction, ith the blades being radially displaceable within a rotor which, in turn, is eccentricall mounted in a housing, turning these pumps fragile a d, th refore, more s s¬ ceptible of f ilure. The pisto t pe hydr ul ic pumps are, uF to no , h most resistant and presenting the best efficie y, hen the relationship between the power suppl ied therπto and the mo n t of dynamic hydraul ic energy produced is considered. These pumps can be of the a:.ιal type, where the pis¬ tons move arallel to the rotor shaft, or of the adial piston t e, in which the pistons move inwardly a d outwardly with regard to a piston eccentricall mounted within a housing, in a operation similar to those of the blade t pe pumps. Due to its rugged construction, the piston PUMPS are capable of providing flow rates up to 1200 1/mιn of pressures iinn tthhee rraannge of 700 kg/cm, without prejudice to the safety re- qu i rements Finally, the centrifugal pumps are used only in hy draulic systems where great volumes of hydraul ic fluid need to be displaced at medium or low pressures, due to its low re sistance to ba kup pressures, turning its control more diffi cult. Hydraulic motors using hydraul ic energy developed b the pumps, both of the rotary and piston types are <*1s widel known from the state of the art. The rotary hydraul ic motors are scarcely used mainl because they can be easily substituted for electric motors The piston motors, in turn, have an operati g principle simi lar to those of the pisto pumps, that is to say, the dis placement of a piston causes the displacement of a give volume of h draul ic fluid. Both the pu s and the iston otors c n be cf single action ty e, when the piston produces work onl i sin le dir tion of its stroke, or of the double action hen the piston produces work in both directions of i stroke. The coup ing of h dr ul ic pumps a d Motors is also technique wid l used for Many ears. However, up to now, hydraulic PUMP a d motor assembly h s not being de lop which could be used fo d iving an independent working ni while at the same time b i g self-suppl ied b the circul ti of a luid in a lo ed h draul i circuit. SUMMARY OF THE INVENTION One ob ective of the present invention is to provi a h draul i ump unit, more rticul rly a isto pum , whi is capable o developing in a closed hydraul ic circuit an ou put power gre ter than the power suppl ied thereto. Another objective of the present invention is pro ide a h dra lic PUMP an motor assembly, more particula a piston pump and motor, connected in a closed hydr ul ic ci cuit, in which the power developed by the said pump unit sufficient for driving the said motor, in order to assure i own driving, while still generating an output power for dri ing n indepe dent working unit. According to the present invention, these objectiv are achieved by the provision of a piston pump of the ty comprising at least a double action piston, the said pump ha ing driving means for receivi an input power, a first pa of crank arms rotatively driven by the said driving means, second pair of crank arms coupled to a movable driven shaft, pair of cra k arms coupling, in an intercrosse Manner, t said first and second pairs of crank ar«s and connection mea coupl ing the said mo able driven shaft to the said pisto whereb upon each rotation of the said driving e ns the pi ton carries out four strokes of h draul ic fluid volumetri displacement. Still in accordance with the present inventio these objectives are a hieved b the provisio of a pist pump an Motor assemb y o the t pe coMprising at least a do ble action piston, the said assembly having a pump unit wi Figure S is a ro s-sec ion view of a oth r emb iment of the PUMP unit shown in figure 7 • Figure 9 is a cross-se ion view of the ump u shown in figure 8, t en ong l ine IX-IX of figur 8> ~ and Figure 10 is a schem tic view of the basic h raul i cui o the isto pump nd motor ssembl of the p se inven ion. DESCRIPTION OF THE PREFERRED EMBODIMENT M kin reference to the drawings, a pisto pump a a piston PUMP and motor asseMbl in accor ing with the prese invention are illustrated in the attached drawings, which a intended to illustrate the presentl preferred embo iments the i ve tion d are ot intended to l imit its sco e. Figure 1 is a cross-section view of a piston p a d motor assembly in accord nce with th present inventi comprising a bo or housing 1 having a suitable shape, driv b a p lley 2 fi ed to a driving sh ft 3 by Means of a e or the l ike. The said driving shaft 3 freely rotates within t sai box 1 supported on ball bearings 5 and a retainer 6 place in a housing 7 of the said bo 1, adjacent to t pulle 2, so s to prevent an hydra ic fluid le k ge ther from. Additionally, the said shaft is also provided with counterb lance wheel S ne to one of its ends. The counterbalance wheel S nd two cams 9, 10, i tended to drive the driving pistons 11, 12 of the s id mot nit are also secured to the said driving shaft 3 by means the said eys 4, as it can be seen from the cross-section il l stration showing details of its connecting portions to t said sh ft 3 and also from figures 2 and 3. The rotational movement of the said cams 9, 10 i converted into alternate movement of the said pistons 11, by cam follower rollers 13 fixed to the lower ends of the sai pi ton 11, 12, b means of U shaped fi ing elements 14, whic legs are formed with transpassing rolls ithin which are r ceive the central shafts 16 of the ball bearings 17, arou hich the said rolle s 13 freel rotate. The said cams 9 and 10 are preferab discs having contour defined b the Archimedes spiral curve equation, s th t i s rotational movement whe convert d i o n alter ate movement of the said pisto s 11, 12, auses h i r ternate movement to be uniform in both dire ion; o to preve,ι 4 pres e peaks i the hydr li fluid bein um e . Referri now more p r+ : cu1 r1y to figu e *. , th hy- au1 I ; pum unit for fluids o the puf.ip nd moto ρ a εsen b ' - ■ ι " accordance ith the pres i ventio i = shown ive by the said dri ing shaft 3 through s ge IS connect d there o b_ ■ a e 4 , hich enga es anothe g ar 1 D fixed to a stations 1 " 1 .' driven shaft 20 having two cranl- arι_= 21 connected thereto by means of ke s 4. The sai sh ft fr el rotate su portpc b l bearings r ceive in sup ort columns 23 and e ch o e n f th« s id cr nl- rms 23 it pro ided wi h ? b ll hea i g 2- in t =. distal en for rotational coupl ing with a pair o ρ i n e cπ=se iston rods 25 which transmit the rotatio mov ment of t e said stationar driven shaft 20 to an upper driver. shaft 26 movable b means of a similar asseMbly or ball bearings 2" provided in the distal ends of the crank arms 2S sec re to the said Movable riven sh ft 26 b Means of e s 4. The said mov ble upper driven shaft 26 freely ro¬ tates supported by bearings 29 secured to a fixing element 30. An anti-ba kup mechanism 31 such as a sprocket is coupl d to the said Movable upper driven shaft 26, so as to pre ent ot;-- tion thereof in a direction contra to a esired one. The i nter-crossed disposition of the piston rods 25 causes each rotation of the driving shaft 3, oi- of the sta¬ tionar driven shaft 20 be transformed in two vertical dis¬ placements of the movable driven shaft 26, and accordingl , of the shaft 32 to which the fi ing element 30 is secured and whi h has the pisto 33 in its end, whereby this piston 33 moves four times within the ylinde 34 upon each rotation oF the driving shaft 3, while in a normal cranl, arm s s em this piston would only move twice. This allows the piston 33 to carr out = hyd aulic flui volumetric displacement withi the c l inde 3" which doubles the dynamic hydraul ic energy of the system, allowing the piston pump and motor assembl not o l to seH suppl b t also to generate an output power fo • " a separate ope a i unit, Since this piston 33 is of the double actio t p unidirectional valves ~ ~ ~ t~ 36 j 37. 31 re d i spos ' ed in the en of the cyl ind r 34, co necting the flui supply l ines ? a the fluid discharge lines 40 thereto. Referring again to figure 1 , the piston pump and m tor asseMbly according to the present invention is shown co prising a rotar directional valve 41, of high flow rate a speed, ha ing a box 42 provided with inlet/outlet openings f hydraul ic fluid 43 within hich is a conversion a d distri ution bushing 44 forMed with four openings 45, which area co responds to the area of each inlet/outlet opening 43, so as prevent interruption of the hydraul ic fluid flow due to clo gi g. A distribution rotor 46 is dispose within the sai bushing 44 so as to control the distribution of the hydrauli fluid in the s stem, which rotor is driven b Means of a gea 47 coupled thereto through a fi e adjust Means 48, wh.ich wil not be described herein in greater details since it is no part of the present invention. Two bearings 49 support the said distribution roto 46 ithin the said bushing 44, so that the motor can freel rotate he driven by the said gear 47 which, in turn, is di rectl driven b a gear 50 secured to the said driving shaft b means of a key 4. In this manner, the said rotar directional valve 4 permits the circulation of the h draul ic fluid from a pressur accumulator 51 to a pressurized reservoir 52 in a closed h draul ic circuit as represented by figure 10, so that the powe or torq e suppl ied to the piston pump and motor assembly o the present invention through the pulley 2 is doubled servi not onl to assure the contin ous working of the pump and mo tor assembly but also to generate an output power, which ca be used to actuate another working unit. Figures 5, 6 and 7 illustrate a second embodiment o the present invention, in which the piston pump and motor as sembly according to the invention is shown having p irs o P i stons. A bo 53, h ving a suitable shape receives a drivin shaft 54 which freely rotates supported by bearings 55 secured to the said bo , with a retainer 56 b ing di posed in a hous¬ ing 57 of the said box to prevent an h dr ul ic ' fluid leakage. gain, a pulley 5δ is sec red by eans of a ke 5 ' to th n of the shaft 54, for trans itti g/receiving a torque. A gear 60 and a counterbalance wheel 61 are fi ed to the said shaft 54 by means of a key 59, which gear 60 engages a second gear 62 connected to a second shaft 63 parallel to the said driving shaft 54 b means of a key 59, hich simul- taneously fixes a second counterbalance wheel 64. The said second sh ft 53 freel rotates within the said box 53 supported on bearings 65 and projects into the pump compartment of the assembl , for driving the pump mech¬ anism as it will be describ d in greater det ils below. Each one of the said shafts 54, 63 has a cam disc 6 attach thereto b means of keys 67. As above mentioned, the said cams 66 have profiles defined according to the Archimeds spiral curve, so that the transformation of the rotational movement of the shafts in a alternate movement of the pistons results in a uniform and constant displacement for avoiding pressure pe ks of the hy¬ draulic fluid. Two cam follower rollers 68 interconnected by a rocker arm 69 are coupled to a first piston 70 by means of a link shaft 71 for the said rocker arm, while the opposed pis¬ ton 74 is also driven b two cam follower rollers 72 intercon¬ nected b a rocker arm 73 secured to the said piston 74 by Means of a link pin 75. This constructive disposition of the present in vention allows a perfect balance of all the force components, while still providing a greater volumetric displ cement due t the utilisation of pairs of pistons. Within the pump compartment, the said second shaf 63 has a gear 76 attached thereto by means of a key 59, whic cooper tes with a second gear 77 integral with an interm diat shaft 78 for transmitting a rotational Movement to the gear 79 which cause the pumping system to rotate. The said gears 79 are fixed to shafts 80, respec tively, and each shaft has a first pair of crank arms 81 at tached thereto by means of ke s 59. SiMilar to the precedi e M bodiment, the shafts 81 rotate on bearings 82 disposed supports 83. The distal ends of the cr nk arms 81 are connect to the distal ends of a second pair of crank arms 84 by mea of intercrossed piston rods 85, whereb the shafts 86, hi freely rotate supported by bearings 87 having a sproc et sy tem 88 coupled to each one thereof, are verticall displac upon rotational movement of the shafts 81. The vertical displacement of the shafts 86 causes displacement of the pistons 89 coupled thereto by connecti members 90. Thus, the pistons 89 Move four tiMes upon ea rotation of the shafts 81, doubling the h raulic flui voluMetric displacement in the system. Again, in order that the pistons f nction as doubl action pistons, adMission 91 and discharge 92 unidirectiona valves are coupled to the ends of the cyl inders 93 withi which the pistons move. Figures 8 and 9 illustrate a second embodiment o the composite pump unit isclosed in figure 7, particularl suitable for direct coupl ing to a motor ssembly. Due to th similarity between this embodiment and the embodi ent shown i fi ure 7, siMilar reference numbers were given to the sam component parts. Shaft 63 having a gear 76 attached thereto b mean of a ey 59 within the housing 94, supported by bearings 9 and a retainer 96, received in a housing 97 of the said bo 94, serve to prevent any hydraul ic fluid le age out of th box. Gear 76 directl engages gear 79, without the inter mediate gear 77 and respective shaft 78, whereby the rotatio of the shaft 63 is transmitted to the shafts 80 by the gear 76 nd 79, with the shafts 80 rotating in opposite directions As alread ex lained with regard to figures 5, 6 an 7, the shafts 80 rotate supported by bearings 82 provided i columns 83, does efining a synchronized stationary dual as sembly b Means of gears. The crank arms 81 fi ed to each one of the respec tive shafts 80 have its distal ends connected to the dista ends of the similar cra k arms 84 b Means of the respective pairs of intercrossed piston rods 85, whereby the rotational movement of the stationary shafts 80 is transformed in a ver¬ tical displacement movement of the shafts 86 to which are at- tached the said crank arms 84. These shafts 86, in turn, rotate supported by bearings 87, with a gear mechanism δδ being used for prevent¬ ing its displacement in a direction contrary to the desired one, and its alternate movement is transmitted to the cylin- ders 89 by means of connecting members 90. According to the present invention, it is provided a piston pump which, upon its volumetric displacement, is capa¬ ble of doubl ing the received power and a piston pump and motor assembly which is capable of self-feeding and producing an output power for driving an independent separate operating unit. Figure 10 schematic illustrates the basic h draul ic system of he present invention, comprising, besides the above-mentioned pressure accumulator 51 and pressurized reser- voir 52, a pump unit B ? a motor unit M, the said high spee directional valve 42, the conventional hydraul ic control valves V and an oil cooler R. Having described the invention, it is to be under¬ stood that the same can suffer several modifica ions, provided that these mo i i a ions do not depart from the spirit and scope of the invention, as defined in the attached claims.

Claims: CLA I MS 1. Pi to pu p of the ty e comprising t least ouble action piston, ha cterized by comprising drivi means (2,3,4) for receiving a input power, a first pai crank arms (21) rotativel actuated b the said driving mea (2,3,4), a second pair of crank arms (2δ) coupled to a movabl driven shaft (26), a pai of crank arms (25) coupl ing in intercrossed manner the said first (21) and second (28 ) p i of cra k a ms, and connecting means (29,30,31) coupl ing th said movab e driving shaft (26) to the said pisto (33 ) whereby upon i s rotation of the said d iving me ns the sai piston arries out fours strokes of hy raul ic fluid volumetri displacement. 2. Pisto pump in accordance with claim 1, charac terized in that the said riving means comprise a d ivin shaft (3) having a driving pulley (2) attached thereto b means of a key (4). 3. Piston PUMP in accord nce with claim 2, charac terized in that the said driving shaft (3) has a gear (18) i n tegral therewith and engaging a second gear (19) integral wit a second stationar riven shaft (20). 4. Piston PUMP in accor ance with claim 3, charac terized in that the said first pair of crank arms (21) is in tegral with the said stationar driven shaft (20). 5. Piston pump in accordance with claim 4, charac terized in that each one of the crank arms (21) of the sai first pair is coupled to an end of each cra k arm (25) of th said pair. 6.. Piston pump in accordance with claim 5, charac terized in that the opposite ends of each crank arm (25) ar coupled in an intercrossed manner to the said cr nk arms (28 of the said seco d pair. 7. Piston PUMP in accordance with claiM 6, charac teri ed in th t the coupl ing between the said cr nk arm (21,28) and the said crank arms (25) comprises bearings (24 therein, integral with a common shaft. 8. Pisto pump i accordance with claim 7, charac terized in that the said ovable drive sha t (26) is coupled to the said piston (33) by means of a support member (30 ) hav ¬ ing a pair of bearings (39) on which the said shaft (26) freely rotates. 9. Piston pump in accordance with claim 8, charac¬ terized in that the s id support member (30) comprises an anti-backup means (31) for securing rotatio of the shaft in a single d i rect i on. 10. Piston pump in accordance with claim 9, charac- terized in that the said anti-backup means (31) comprises a sprocket. 11. Piston pump and motor assembly, of the type com¬ prising a piston pump unit and a pi ton motor unit coupled in a closed hydraulic circuit, each one of the s id pump and α- tor units having at least one double action piston, character¬ ized by comprising driving means (2,3,4,54,58,63) for receiving an input power, at least a first pair of crank arms (21,81) rotatively driven by the said driving Means (2,3,4,54,58,63), at least a second pair of crank arms (28,84) coupled to at least one movable driven shaft (26,86), at least a pair of crank arms (25,85) coupling in a intercrossed Manner the said first and second pairs of crank arms (21,26,81,84), connecting means (29,30,32,90) coupling the said Movable driven shaft (26,86) to at least one piston (33,89) of the said PUMP unit, whereby upon rotation of the said driving means the s id pistons carry out four strokes of hydraul ic fluids voluMetric displacement, means (42) for directioning the said displaced h draulic fluid for actuating the sai driving means, am means (9,10,66) integral with the sai driving means (3,54,58,63) and cam follower means (13,68,72) coupled to each piston of the said motor unit, whereb th said pistons of the motor unit cause a hydraulic fluid dis placement which is reinforced by the said pistons of the ump u it. 12. Piston pump and motor asseMbly in accordanc with claiM 11, characterized in that the said driving Mean comprise a driving sh ft (3,54) having a pulle (2,58) at tached thereto by means of a key (4,59). 13. Piston pump and motor assembly in accordanc with claim 12, haracterize in th t the said driving sh (3, 54) has a gear (18,60) integral therewith engaging a se ond gear (19,62,76) integral with a stationary d iven h (20,63,80) . 14. Pisto pump and motor assembly in accordan with claim 13, characterized in that the said at least o first pair of cra k arms (21,81) is integral with the sa stationary shaft (20,80). 15. Piston PUMP and motor assembly in accordan with claim 14, characterized in that each one of the sa cr nk arms (21,81) of the said at least one first pair is co pled to an en of each said cra arm (25,85) of the said least one pair. 16. Piston PUMP and motor assembly in accordan with claim 15, characterized in that the opposite ends of ea crank arm (25,85) are coupled in n intercrossed manner to t said crank arms (28,84) of the said at least one second pair. 17. Piston pump and motor assembly in accordan with clai 16, characterized in that the s id at least o movable shaft (26,86) is coupled to the said at least one pi ton (33,89) by means of a support member (30,90) having a pai of bearings (29,87) on which the said shaft (26,86) freely r tates. 18. Piston pump and motor assembly in accordanc with claim 17, characterized in that the said support meMbe (30,90) comprises an anti-backup Means (31,88) for securin the rotation of the shaft in a single direction. 19. Piston pump and motor assembly in accordanc with claim 11, characterized in that the said means for direc tioning the hydraulic fluid comprises hi h speed directiona valve (42) . 20. Piston pump and motor assembly in accordanc with claim 11, characterized in that the said cam means com prise cam discs (,10,66). 21. Piston pump and motor assembly i accordanc with claim 20, characterized in that the said cam disc (9,10,66) h ve a contour defined in accordance with th Archimedes spiral c rve. 22. Piston pump and motor assembly in accordanc with claim 11, characterized in that the said cam follower means comprise rollers (13,68,72).

Inventors: NASCIMENTO PACHECO CLAUDIO, NASCIMENTO PACHECO JOSE MAURIC, NASCIMENTO PACHECO, CLAUDIO, NASCIMENTO PACHECO, JOSE, MAURICIO
Applicants: NASCIMENTO PACHECO CLAUDIO, NASCIMENTO PACHECO JOSE MAURIC, NASCIMENTO PACHECO, CLAUDIO, NASCIMENTO PACHECO, JOSE, MAURICIO
Application year: 1990
Main classification: F04B9
IPC codes: F01B9, F04B9