EP0471098A1 - Dispositif hydraulique à piston - Google Patents

Dispositif hydraulique à piston Download PDF

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Publication number
EP0471098A1
EP0471098A1 EP90115518A EP90115518A EP0471098A1 EP 0471098 A1 EP0471098 A1 EP 0471098A1 EP 90115518 A EP90115518 A EP 90115518A EP 90115518 A EP90115518 A EP 90115518A EP 0471098 A1 EP0471098 A1 EP 0471098A1
Authority
EP
European Patent Office
Prior art keywords
pistons
rotor
working liquid
eccentric shaft
disposed
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP90115518A
Other languages
German (de)
English (en)
Inventor
Hisao Hasegawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to EP90115518A priority Critical patent/EP0471098A1/fr
Publication of EP0471098A1 publication Critical patent/EP0471098A1/fr
Priority to US07/969,515 priority patent/US5244356A/en
Priority claimed from US07/969,515 external-priority patent/US5244356A/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
    • F04B1/10—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary
    • F04B1/107—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the outer ends of the cylinders
    • F04B1/1071—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the outer ends of the cylinders with rotary cylinder blocks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
    • F04B1/053—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement with actuating or actuated elements at the inner ends of the cylinders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
    • F04B1/06—Control
    • F04B1/066—Control by changing the phase relationship between the actuating cam and the distributing means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
    • F04B1/10—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary
    • F04B1/113—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the inner ends of the cylinders
    • F04B1/1133—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the inner ends of the cylinders with rotary cylinder blocks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/10—Other safety measures
    • F04B49/103—Responsive to speed

Definitions

  • This invention is related, in a broad sense, to a hydraulic piston apparatus and particularly to a hydraulic pump and a hydraulic motor as a hydraulic piston apparatus.
  • variable capacity hydraulic piston apparatus of a variable capacity type which is simple in structure and has a long service life.
  • the "piston” used herein is of the type for feeding and receiving a hydraulic pressure within a cylinder and in which its length (whether it is long or not) with respect to its diameter is not questioned.
  • a linkage between the cam plate 3 and piston rods 4, 4a, and a service life of a connecting portion between an input rotational shaft 5 and the cam plate 3 have heretofore been considered to include problems.
  • liquid current becomes an alternating current owing to reciprocating motion.
  • a method for sealing a current plate for converting the alternating current to an unidirectional direct current also becomes a big problem.
  • the axial pump cannot escape from this problem as long as its has the same construction.
  • a hydraulic piston apparatus is designed such that a piston is actuated using an eccentric shaft.
  • a hydraulic piston apparatus of the first invention there is an eccentric shaft.
  • This rotor has the eccentric shaft eccentrically disposed therein.
  • working liquid current straightening means there is working liquid current straightening means. This working liquid current straightening means is disposed in such a manner as to contact with a working liquid inlet and outlet port of the piston.
  • pistons there are a plurality of pistons. These pistons are radially disposed within the rotor, and the heads of the pistons are normally contacted with the inner periphery of the stator. And there is working liquid current straightening means. This working liquid current straightening means is disposed in such a manner as to contact with a working liquid current inlet and outlet port of the pistons.
  • variable capacity hydraulic piston apparatus of the third invention an eccentric shaft is rotatable. Regarding all the remaining construction, please refer to the construction of the first and the second invention.
  • This invention is a hydraulic piston apparatus comprises an eccentric shaft rotor, a stator having the eccentric shaft rotor eccentrically disposed therein, a plurality of pistons radially disposed within the stator, heads of the pistons being normally contacted with the outer periphery of the eccentric shaft rotor, and working liquid current straightening means communicating with a working liquid inlet and outlet port of each of the pistons and including timing detection means such as rotary encoder for detecting the timing for rotation of the eccentric shaft rotor and a change-over valve controlled by the timing detection means.
  • timing detection means such as rotary encoder for detecting the timing for rotation of the eccentric shaft rotor and a change-over valve controlled by the timing detection means.
  • a hydraulic piston apparatus of the fifth invention first, there is a rotor. Next, there are a plurality of eccentric shafts. These eccentric shafts are provided to the rotor. Furthermore, there are a plurality of pistons. Each head of the pistons is normally contacted with the outer periphery of each of the eccentric shafts and piston motion of said head is phasewise split. And there is holding means.
  • This holding means includes a housing, a stator, etc. for holding the pistons. Furthermore, there is working liquid current straightening means.
  • This working liquid current straightening means is communicated with a working liquid inlet and outlet port of each of the pistons and includes timing detection means such as rotary encoder for detecting the timing for rotation of the rotor and a change-over valve controlled by the timing detection means.
  • timing detection means such as rotary encoder for detecting the timing for rotation of the rotor and a change-over valve controlled by the timing detection means.
  • a rotational shaft there is a rotational shaft first. Then, there are a plurality of cylinders. The cylinders are disposed parallel with the rotational shaft. Arrangement being such that piston motion of a piston head disposed within each of the cylinders is phasewise split. And there are a plurality of piston units. These piston units are used for the plurality of cylinders, respectively. Furthermore, there is a cam. This cam is adapted to permit a part of the plurality of piston units to be engaged therewith. The cam is disposed on the rotational shaft. The piston units are caused to effect piston motion in the longitudinal direction of the rotational shaft by rotation of the rotational shaft. Finally, there is working liquid current straightening means.
  • This working liquid current straightening means includes timing detection means such as rotary encoder for detecting the timing for rotation of the rotational shaft and a change-over valve controlled by the timing detection means.
  • the timing means includes timing variable means capable of varying the timing control time such as rotary joint or the like.
  • the rotor has the eccentric shaft disposed therein, a plurality of pistons are radially disposed within the rotor, and the heads of the pistons are normally contacted with the outer periphery of the eccentric shaft. Accordingly, the piston is actuated at a piston time difference by rotation of the rotor.
  • the working liquid current straightening means is disposed in such a manner as to contact with the working liquid inlet and outlet port of the piston. Accordingly, the working liquid current is straightened here.
  • the rotor has the eccentric shaft concentrically disposed therein, and the stator is provided therein with the rotor, the plurality of pistons being radially disposed within the rotor, the heads of the pistons being normally contacted with the inner periphery of the stator. Accordingly, these pistons are actuated at a piston time difference by rotation of the rotor.
  • the working liquid current straightening means is disposed in such a manner as to contact with the working liquid current inlet and outlet port of the pistons. Accordingly, the working liquid current is straightened here.
  • the eccentric shaft is rotatable. Accordingly, an intaking and discharging quantity of the working liquid is changed by changing the eccentric angle.
  • the functions of the first and the second invention please refer to the functions of the first and the second invention.
  • the stator having the eccentric shaft rotor eccentrically disposed therein is provided with the plurality of pistons radially disposed within the stator, and heads of the pistons are normally contacted with the outer periphery of the eccentric shaft rotor. Accordingly, the pistons are actuated at a piston time difference by rotation of the eccentric shaft rotor.
  • the working liquid current straightening means communicating with the working liquid inlet and outlet port of each of the pistons and including timing detection means such as rotary encoder for detecting the timing for rotation of the eccentric shaft rotor and a change-over valve controlled by the timing detection means straightens the working liquid current as working liquid current straightening means having no sliding portion.
  • timing detection means such as rotary encoder for detecting the timing for rotation of the eccentric shaft rotor and a change-over valve controlled by the timing detection means straightens the working liquid current as working liquid current straightening means having no sliding portion.
  • a hydraulic piston apparatus of the fifth invention The function of a hydraulic piston apparatus of the fifth invention will now be described.
  • the plurality of eccentric shafts are provided to the rotor, the plurality of pistons being disposed such that each head of the pistons is normally contacted with the outer periphery of each of the eccentric shafts and piston motion of the head is phasewise split, the pistons being held by the holding means. Accordingly, the pistons are actuated at a piston time difference by rotation of the rotor.
  • the working liquid current straightening means is communicated with a working liquid inlet and outlet port of each of the pistons and includes timing detection means such as rotary encoder for detecting the timing for rotation of the rotor and a change-over valve controlled by the timing detection means. Accordingly, the working liquid current is straightened by switching the change-over valve in such a manner as to match the timing with rotation of the rotor.
  • the plurality of cylinders are disposed parallel with the rotational shaft. Arrangement being such that piston motion of a piston head disposed within each of the cylinders is phasewise split. And the plurality of piston units are used for the plurality of cylinders, respectively. Accordingly, there can be obtained phasewise split piston motion.
  • the rotational shaft is provided with the cam and this cam is adapted to permit a part of the plurality of piston units to be engaged therewith.
  • the cam is disposed on the rotational shaft. This cam causes the piston units to effect piston motion in the longitudinal direction of the rotational shaft in accordance with rotation of the rotational shaft. Accordingly, a piston motion is effected by this rotation.
  • the working liquid current straightening means including the timing detection means such as rotary encoder for detecting the timing for rotation of the rotational shaft and the change-over valve controlled by the timing detection means straightens the working liquid current from the pistons.
  • the timing means includes timing variable means capable of varying the timing control time. Accordingly, the intaking and discharging quantity of the working liquid can be varied by this. Regarding all the remaining functions, please refer to the functions of the fourth and the fifth invention respectively.
  • Fig. 1 is a front sectional view of one embodiment of a hydraulic piston apparatus according to the present invention.
  • Fig. 2 is a side view of a modified embodiment of Fig. 1.
  • Fig. 3 is a side view of one embodiment of the prior art.
  • Fig. 4 is a chart showing a relation between intaking and discharging quantities of working liquid of the embodiment of Fig. 1 into and from each piston and time.
  • Fig. 5 is an illustration, when taken at each port, of Fig. 4.
  • Fig. 6 is a front sectional view of one embodiment of another embodiment.
  • Fig. 7 is an explanatory view of one embodiment of the conventional piston.
  • Fig. 8 is a front sectional view of one embodiment of a variable capacity type hydraulic piston apparatus.
  • Fig. 9 is a comparison chart of angle of rotation of a cam of the embodiment of Fig. 8 and an average discharging rate of working liquid.
  • Fig. 10 is a front sectional view of one embodiment of still another invention.
  • Fig. 11 is one example in which pistons are linearly arranged
  • Fig. 11a is a front view of a cam portion thereof
  • Fig. 9(b) is a whole side sectional view.
  • Fig. 12 is an illustration of the pistons P radially arranged
  • Fig. 12(a) is a front view of a portion of cams C1 through C3
  • Fig. 12(b) is a side sectional view of its entirety.
  • Fig. 13 is a chart showing the change-over timing of three port valves for intaking and discharging working liquid in a cylinder chamber of the embodiment of Fig. 10.
  • Fig. 14 is a front sectional view showing a tracer valve and a change-over cam according to another embodiment of Fig. 10 and nearby.
  • Fig. 15 is a side view showing a tracer valve and a change-over cam according to still another embodiment of Fig. 10 and nearby.
  • Fig. 16 is a front sectional view of one embodiment of a swing motor of Fig. 15.
  • Fig. 17 is a block diagram of one embodiment showing a countermeasure for time delay required for change-over.
  • Fig. 18 is a side sectional view of another embodiment of Fig. 1.
  • Fig. 19 is a side sectional view of still another embodiment of Fig. 1.
  • Fig. 20 is a side view of one embodiment showing the construction of a hydraulic piston apparatus according to still another invention and in which a part of its pistons is omitted.
  • Fig. 21 is a front view of the embodiment of Fig. 20.
  • a rotor is provided with three piston and cylinder assemblies embedded therein at equal 120° distances.
  • Fig. 1 is a front sectional view of the above, and Fig. 2 is a side view thereof.
  • a first cylinder S is in a position at 0° in the sectional view and a third cylinder S2 is in a position at 180° and therefore four cylinders are provided or embedded.
  • the stator ST and a cam C acting as an eccentric shaft are fixed.
  • the piston P1 When the rotor R is rotated clockwise, the piston P1 is moved toward the center of the rotor R along the cam C in an initial stage of its rotation in Fig. 1. Therefore, it intakes working liquid from a port A (in the drawing, a spring for urging the piston P against the rotor R is omitted. The same is true hereinafter).
  • the piston P3 intakes the working liquid from the port A.
  • the piston 2 is moved outward to discharge the working liquid to a port B.
  • Fig. 4 shows a chart showing a relation between the working liquid intaken or discharged and strokes of the pistons P1 through P3 when the rotor R is rotated clockwise and presuming the position of the piston P1 of Fig. 1 is 0° .
  • the waveforms shown in Fig. 4 are obtained when the configuration of the cam C is determined such the action of the pistons P resemble to a sine waveform every time the rotor R makes one full rotation.
  • Each piston P repeats intaking and discharging operation in a state displaced phasewise by 120° .
  • grooves A1 and B1 act as current straighteners. Therefore, if the intaking and discharging states of the working liquid of the respective pistons P are composed, the port A keeps intaking the working liquid and the other port B keeps discharging the working liquid as shown in Fig. 5.
  • the grooves A1 and B1 do the same work as the cam plate type pump. If the rotating direction of the rotor R is reversed, the port A discharges the working liquid and the port B intakes it this time. If the stroke of the piston P is represented by D and the diameter by d, the discharge capacity and intake capacity per on full rotation of the rotational shaft becomes 3D ⁇ d2/4 in case of three pistons P.
  • a current straightening shaft is disposed at an inner side of the rotor R and has current straightening grooves A2 and B2 formed in its outer surface. Each of the current straightening grooves A2 and B2 is provided with a port. If the center of the stator ST is displaced from the centers of the rotor R and current straightening shaft RF, it works quite in the same way as that of Fig. 1. Although the sealing between the rotor R and the current straightening shaft RF becomes much easier because the dimension of the space formed therebetween is smaller than that mentioned above, the sliding portion is not eliminated.
  • variable capacity can be obtained by controlling the displacing amount of the cam C.
  • the cam C receives the pressure of the piston P straight, a simple structure and an improved strength are demanded in order to increase reliability. Therefore, in order to control the displacing amount of the cam C, a large-scaled mechanism is resulted and the initial object is impossible to achieve. Moreover, this is no use at all for solving the problem of working liquid leakage of the current straightening mechanism.
  • the cam C is displaced in the direction of 0° . If the cam C is slightly rotated to set the direction of displacement in the direction of 270° and the rotor R is rotated clockwise as in one embodiment of the third invention shown in Fig. 8, the piston P1 intakes the working liquid within 0° to 90° and discharges the working liquid within 90° to 180° . Moreover, the intaking and discharging rates are equal. And it discharges the working liquid within 180° to 270° and discharges it within 270° to 0° . Thus, both are equal. Therefore, the balance of the intaken working liquid and the discharged working liquid becomes zero. The same is true to the port B.
  • the rotor R is merely rotated idle and the discharging rate becomes zero.
  • the ripple portion exists but in case of three cylinders, the ripple portion is also intaken and discharged between the cylinders. Therefore, the ripple portion which appears on the outside piping is extremely reduced. Furthermore, if the number of the cylinders is increased, the ripple portion is more decreased. Therefore, thoughtless employment of multicylinder is not advantageous in view of strength. From a practical view point, approximately three to 9 cylinders are proper.
  • the discharging quantity Q of the pump becomes maximum when the facing direction of the cam C is 0° .
  • Fig 10 is one embodiment of the fourth invention.
  • the piston P1 is changed over and connected to a port A or a port B with a three-port two-position electromagnetic valve V1.
  • Other pistons P2 and P3 are also connected to the port A or B with three-port two-position electromagnetic change-over valves V2 and V3 respectively.
  • a rotary encoder E is mounted on the shaft in order to detect an angle of rotation of the input shaft.
  • Fig. 11 shows one example wherein the pistons P are linearly arranged, Fig. 11(a) is a front view of the cam C portion thereof, and Fig. 11(b) is a side sectional view of its entirety.
  • Fig. 12 shows another example wherein the pistons P are radially arranged, Fig. 12(a) is a front view of the cams C 1 through 3 portions, and fig. 12(b) is a side sectional view of its entirety.
  • the number of the pistons is an even number.
  • Fig. 11 there can be contemplated a combination type of Fig. 11 with Fig. 12. That is, instead of providing radial type pistons arranged in a multiplex manner or providing radial type pistons on the same plane (though it becomes large), the pistons are arranged in the longitudinal direction of the rotor R. Owing to the foregoing arrangement, the number of pistons can be unlimitedly increased as a multiplex radial type.
  • the piston P2 is switched in the state where the phase is delayed by 120° and the piston P3 is switched in further delayed state by 120° .
  • the rotary encoder E was used in order to detect the angle of rotation of the input shaft (eccentric cam C). It is to be noted that the types of the encoder are not questioned and they may be optical type, magnetic type and mechanical type as long as they can detect the angle with high accuracy.
  • the three-port tracer valves 10a, 10b and 10c are equally radially arranged on a ring 10 and the rotational shaft 12 connected to the rotor R is provided with a change-over cam 11 (having a configuration able to be switched every 180° ) for controlling the valves 10a, 10b and 10c. And by rotating the angle of the ring 10 rightward and leftward, the switching timing o the straightening current can be adjusted in the same manner as mentioned in the preceding paragraph. By this, it becomes a variable capacity type.
  • This ring 10 can also be made into a two-way discharging variable capacity type pump by means of rotation by ⁇ 90° about a position of 90° or 270° while maintaining the unidirectional rotation of the rotational shaft 12.
  • the tracer valves 10a, 10b and 10c are not desirous to be rotated, the same effect can be obtained by shifting the phase of the change-over cam 11 with respect to the eccentric cam C for driving the pistons C.
  • a concrete example of this, as shown in Fig. 15, is designed such that a swinging motor 13 is interposed between the cam C and the change-over cam 11, and a working liquid pressure P s is applied to the center of the rotational shaft 12 from an external portion via the rotary joint 14.
  • the singing motor 13 has a shaft 13a which is rotated to an angle where the internal spring 13b and working liquid pressure P s are balanced, the phase of the change-over cam 11 can easily be controlled only by the working liquid pressure.
  • control disadvantages are taken place. That is, it takes a certain time from the time when the angle of rotation of the rotational shaft 12 is detected till the time when controlling of the current straightening valve is over. The reason is as follows. If the speed of rotation of the rotational shaft 12 is varied, the time requires for the rotational shaft 12 to make one full rotation is varied. However, if the delay time ⁇ of the straightening current is constant, the switching phase is greatly displaced in proportion to the speed of rotation.
  • phase advanced signals ⁇ 1', ⁇ 2' ... ... ⁇ 3',n pieces of current straightening change-over valves are controlled. If correction is performed in this way, the pump is normally operated.
  • the current straightening grooves A1 and B1 shown in Fig. 1 may be brought to the side of the stator ST as shown in Fig. 18. This is true to Fig. 18.
  • the signal ⁇ from the rotation detecting means is converted to a speed signal
  • it may be designed such that a rotation speed detector besides the angle detector is mounted on the shaft and the advance phase circuit is controlled based on the signal.
  • a hydraulic piston apparatus of the sixth invention will be described with reference to a side view of Fig. 20 and a front view of Fig. 20.
  • Fig. 20 two pistons are omitted for simplicity of the drawing.
  • this piston PS is designed as follows. That is, there are a plurality of cylinders SY. The plurality of cylinders SY are disposed such that piston motion of piston heads PH in the cylinders SY is phasewise equally divided. Concretely, three pistons PS are arranged at a distance of 120° in this embodiment as shown in Fig. 21. And the piston units PU are caused to perform a piston motion in the state where the piston units PU are displaced in phase by 120° . The plurality of piston units PU are inserted in the plurality of cylinders SY respectively.
  • the rotational shaft SP is provided with a cam CS.
  • This cam CS is formed of a groove having a shape formed of a continuous letters of S. Engaged in this cam CS are cam groove guides as a part of the plurality of piston units PU.
  • this cam CS is adapted to cause the respective piston units PU to effect a piston motion in accordance with the rotation of the rotational shaft SP.
  • this working liquid current straightening means is not illustrated, this is something like that of Fig. 4 and that of Fig. 5, and comprises timing detecting means such as rotary encoder, etc., for detecting the timing of the rotation of the rotational shaft, and a change-over valve controlled by the timing detecting means.
  • timing detecting means such as rotary encoder, etc.
  • a hydraulic piston apparatus As a hydraulic piston apparatus according to the present invention is such constructed as mentioned above, such effects as described in the above description on each invention were produced. Particularly, it became a hydraulic piston apparatus which is very simple in construction and which has a long service life. Furthermore, in the third and seventh invention, a variable capacity type hydraulic piston apparatus became easy.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
EP90115518A 1990-05-23 1990-08-13 Dispositif hydraulique à piston Withdrawn EP0471098A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP90115518A EP0471098A1 (fr) 1990-08-13 1990-08-13 Dispositif hydraulique à piston
US07/969,515 US5244356A (en) 1990-05-23 1992-10-30 Hydraulic piston apparatus

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP90115518A EP0471098A1 (fr) 1990-08-13 1990-08-13 Dispositif hydraulique à piston
US07/969,515 US5244356A (en) 1990-05-23 1992-10-30 Hydraulic piston apparatus

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EP0471098A1 true EP0471098A1 (fr) 1992-02-19

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997043177A1 (fr) * 1996-05-10 1997-11-20 Zf Luftfahrttechnik Gmbh Plateau oscillant a pompe integree pour helicoptere
GB2366601A (en) * 2000-09-12 2002-03-13 Lucas Industries Ltd Pump arrangement within a drive shaft
EP1319835A2 (fr) * 2001-12-13 2003-06-18 Caterpillar Inc. Machine à pistons radiaux
EP1319836A2 (fr) * 2001-12-13 2003-06-18 Caterpillar Inc. Machine à pistons radiaux avec contrôle numérique
CN103052799A (zh) * 2010-02-23 2013-04-17 阿尔特弥斯智能动力有限公司 流体工作机器和运行流体工作机器的方法
US9739266B2 (en) 2010-02-23 2017-08-22 Artemis Intelligent Power Limited Fluid-working machine and method of operating a fluid-working machine

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH158615A (de) * 1931-02-24 1932-11-30 Paul Dr Ing V Vago Flüssigkeitspumpe.
GB464495A (en) * 1934-10-30 1937-04-16 Georges Peguet Improvements in rotary pumps with radial pistons
FR1240080A (fr) * 1959-07-23 1960-09-02 Rech Etudes Production Sarl Pompe hydraulique à cylindres en étoile pour hautes pressions et à régime de rotation élevé
LU70899A1 (fr) * 1973-09-17 1975-01-02
US4352319A (en) * 1979-08-17 1982-10-05 Fritz Wegerdt Positive control for hydrostatic motors, especially radial piston motors
WO1991005163A1 (fr) * 1988-09-29 1991-04-18 The University Of Edinburgh Machine a fonctionnement fluidique ameliore

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH158615A (de) * 1931-02-24 1932-11-30 Paul Dr Ing V Vago Flüssigkeitspumpe.
GB464495A (en) * 1934-10-30 1937-04-16 Georges Peguet Improvements in rotary pumps with radial pistons
FR1240080A (fr) * 1959-07-23 1960-09-02 Rech Etudes Production Sarl Pompe hydraulique à cylindres en étoile pour hautes pressions et à régime de rotation élevé
LU70899A1 (fr) * 1973-09-17 1975-01-02
US4352319A (en) * 1979-08-17 1982-10-05 Fritz Wegerdt Positive control for hydrostatic motors, especially radial piston motors
WO1991005163A1 (fr) * 1988-09-29 1991-04-18 The University Of Edinburgh Machine a fonctionnement fluidique ameliore

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997043177A1 (fr) * 1996-05-10 1997-11-20 Zf Luftfahrttechnik Gmbh Plateau oscillant a pompe integree pour helicoptere
US6109876A (en) * 1996-05-10 2000-08-29 Zf Luftfahrttechnik Gmbh Helicopter swash plate with integrated pump
GB2366601A (en) * 2000-09-12 2002-03-13 Lucas Industries Ltd Pump arrangement within a drive shaft
EP1319835A2 (fr) * 2001-12-13 2003-06-18 Caterpillar Inc. Machine à pistons radiaux
EP1319836A2 (fr) * 2001-12-13 2003-06-18 Caterpillar Inc. Machine à pistons radiaux avec contrôle numérique
EP1319836A3 (fr) * 2001-12-13 2003-11-26 Caterpillar Inc. Machine à pistons radiaux avec contrôle numérique
EP1319835A3 (fr) * 2001-12-13 2003-11-26 Caterpillar Inc. Machine à pistons radiaux
CN103052799A (zh) * 2010-02-23 2013-04-17 阿尔特弥斯智能动力有限公司 流体工作机器和运行流体工作机器的方法
US9133838B2 (en) 2010-02-23 2015-09-15 Artemis Intelligent Power Limited Fluid-working machine and method of operating a fluid-working machine
US9133839B2 (en) 2010-02-23 2015-09-15 Artemis Intelligent Power Limited Fluid-working machine and method of detecting a fault
CN103052799B (zh) * 2010-02-23 2015-12-16 阿尔特弥斯智能动力有限公司 流体工作机器和运行流体工作机器的方法
US9739266B2 (en) 2010-02-23 2017-08-22 Artemis Intelligent Power Limited Fluid-working machine and method of operating a fluid-working machine

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