EP0234133B1 - Rotary fluid energy converter - Google Patents
Rotary fluid energy converter Download PDFInfo
- Publication number
- EP0234133B1 EP0234133B1 EP19860400385 EP86400385A EP0234133B1 EP 0234133 B1 EP0234133 B1 EP 0234133B1 EP 19860400385 EP19860400385 EP 19860400385 EP 86400385 A EP86400385 A EP 86400385A EP 0234133 B1 EP0234133 B1 EP 0234133B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- pressure
- fluid
- bearings
- piston
- ring
- 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.)
- Expired
Links
Images
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
Definitions
- the present invention relates to a rotary fluid energy converter that is used either as a hydraulic pump or as a hydraulic motor of the hydrostatic type.
- a conventional rotary energy converter of this kind is employed as a hydrostatic hydraulic pump or motor and always uses mechanisms, such as cam mechanisms and linkages, for converting rotary power applied to its input shaft into rectilinear motion of a piston, plunger, or the like and for converting such rectilinear motion of the piston into rotary motion of its output shaft. Since its components are pressed against each other or a twisting force is applied to some components, the converter must employ bearings that make use of either the wedging action of oil films utilizing oiliness or viscosity of lubricating oil or the rolling action of balls, rollers, or the like. Therefore, an oil having an appropriate viscosity is required to be used as working fluid.
- this known converter comprises a housing having a tapering surface in its inner surface, a torque ring which is closely held against the tapering surface of the housing via first static pressure bearings disposed circumferentially regularly spaced from each other, said ring having flat surfaces corresponding to the first bearings on its inner surface, a plurality of pistons disposed on the inner side of the ring and having their front ends connected to the flat surfaces of the ring via second static pressure bearings, a cylinder barrel for slidably supporting the bottom ends of the pistons, a pintle being slidable perpendicularly to the axis of the housing and supposing the barrel, chambers formed between each piston and the barrel whose volume alternately increases and decreases during rotation of the housing relatively to the ring, a pair of fluid communication passages for communicating with the chambers whose volumes are increasing and decreasing, and fluid passages for introducing fluid from the chambers into the first and second bearings.
- each first static pressure bearing having a single pressure pocket
- the center of pressure of each bearing is maintained at a certain position and so the ring is submitted to another couple of forces being produced in a position being off the axis of rotation.
- This structure is now described by referring to Figs. 11 and 12, where the static pressure in each first static pressure bearing a produces a force Fa that acts along a line of action Ls.
- This line L a passes across the center of pressure (geometrical center) b of the bearing a, and every line of action La focus toward a point d on the axis m of both the housing c and the torque ring k.
- the static pressure in each second static pressure bearing e produces a force F b that acts along a line of action L b . Every such line of action L b , (median lines g of the pistons f), focus toward a point i on the axis n of the pintle h.
- the center g of the pintle f periodically moves away from the pressure center (geometrical center) b of the bearing a,while following an elliptic orbit p as shown in Fig. 12.
- the movement of the center g relative to the pressure center b along the axis X is needed to produce a couple of forces about the axis of rotation on the ring k.
- displacement along axis Y bends or twists the ring k. This can impair the features of this system, i.e., excellent durability and the ability to run smoothly and efficiently.
- a converter characterized in that it further comprises : at least two axially adjacent pressure pockets formed in each of the first static means for automatically selectively distributing pressure fluid into said pressure pockets so that when the median axis of the piston is displaced relatively to the median axis of the corresponding pressure bearing the pressure pockets being remoter from said median axis of the piston have a pressure at least inferior as compared to the pressure pockets being closer to said axis.
- said means for automatically selectively distributing pressure fluid into the pressure pockets are constituted of restrictors through which the fluid flowing out of the chamber is distributed to the corresponding pressure pockets.
- said means for automatically selectively distributing pressure fluid into the pressure pockets are constituted of slide valve elements for selectively intermitting the supply of fluid into said remoter pressure pockets by making use of the axial relative movement between each piston and the torque ring.
- each fluid leakage gap of the bearings that is remoter from each piston becomes slightly larger than each fluid leakage gap of the bearings that is closer to each piston by the elastic deformation of the torque ring due to hydraulic pressure, so that the pressure inside each pressure pocket remoter from each piston becomes lower than the pressure inside each pressure pocket closer to each piston.
- the center of pressure of each first bearing comes closer to each corresponding piston than the geometrical center.
- the axial distance separating the center of pressure from the center of each piston is automatically reduced.
- each slide valve element cuts off the supply of pressure fluid into some pressure pockets, so that the center of pressure of each first bearing comes closer to the piston than the geometrical center. As a result, the axial gap between the center of pressure and the center of each piston is automatically reduced.
- FIG. 1-10 there is shown an energy converter according to the invention.
- This converter comprises a cylindrical housing 1 with a bottom portion, and a torque ring 2 is rotatably and closely held on the inner surface of the housing 1 via first static pressure bearings 3.
- the housing 1 is provided with an opening la at one of its ends.
- the inner surface of the housing has a surface 4 tapering toward the opening la, and the ring 2 is in contact with this tapering surface 4.
- the ring 2 is shaped like a cup and has a peripheral wall 2a presenting the same apical angle as the tapering surface 4.
- a rotating shaft 6 is formed integrally with the ring 2 and protrudes from one of its axial ends.
- the front end portion of the shaft 6 extends outwardly from the housing 1 through the opening la.
- the first bearings 3 rigidly comprise shoes 5 being rigidly fixed to the outer surface of the ring 2 at required positions, each shoe 5 being pressed on the tapering surface 4 of the housing 1.
- Each shoe 5 is provided with a pair of pressure pockets, 7a and 7b, axially neighboring one another. Hydraulic pressure is introduced into the pockets 7a and 7b.
- An odd number of bearings 3 are circumferentially regularly spaced apart from one another.
- the pockets 7a and 7b of each shoe 5 is surrounded by surrounding portions 5a, 5b, 5c which are shaped so that their cross section protrudes toward the tapering surface 4 as shown in Figs. 5-7.
- Each shoe 5 is in sliding contact with the tapering surface 4 by a small area.
- the surrounding portions 5a-5c are so shaped that they are not parallel to the axis of rotation X.
- the surrounding portion 5a perpendicular to the axis of rotation X is straight in shape.
- the surrounding portion 5b is shaped like the letter "V”.
- the surrounding portion 5c is shaped in a zigzag manner.
- the inner surface of the torque ring 2 has flat surfaces 2c at positions corresponding to the bearings 3.
- the pistons 8 are disposed at positions corresponding to the inner flat surfaces 2c.
- the front ends 8a of the pistons 8 are pressed against their corresponding surfaces 2c via second static pressure bearings 9.
- the bearings 9 are made flat so that the front ends 8a of the pistons 8 come into close contact with their corresponding surfaces 2c.
- Each of the front end 8a has a pressure pocket 11 into which hydraulic pressure is introduced.
- the base end of each piston 8 is held by a piston retainer 12.
- a chamber 13 is formed between the retainer 12 and the piston 8 for the admission of fluid.
- the piston retainer 12 consists of a pintle 14 having a sliding portion 14a cooperating with an annular cylinder barrel 15.
- the sliding portion 14a is supported on the housing 1.
- the pintle 14 can rotate about an axis n being parallel to the axis m of both the housing 1 and the torque ring 2.
- the barrel 15 is rotatably fitted over the outer periphery of the pintle 14.
- the barrel 15 is provided with cylinders 16 which are regularly circumferentially spaced apart from one another and are arranged radially.
- the axis of each cylinder 16 is substantially perpendicular to the outer surface of the pintle 14.
- the pistons 8 are fitted in the cylinders 16 so as to be slidable.
- each piston 8 and the inner surface of each cylinder 16 form the aforementioned chamber 13.
- the barrel 15 is connected to the torque ring 2 via an Oldham coupling 20 or similar, so that the barrel can rotate at the same angular velocity as the ring 2.
- the pintle 14 takes the form of a truncated cone whose outer surface makes an apical angle substantially equal to the apical angle formed by the peripheral wall 2a of the ring 2.
- the pistons 8 are so held that they can move back and forth perpendicularly to the peripheral wall 2a of the ring 2.
- the sliding portion 14a of the pintle 14 is shaped as a longitudinally elongated block with a trapezoidal cross section.
- the sliding portion 14a is slidably fitted in a trapezoidal groove 19 formed in the housing 1.
- the pintle 14 is held in such a way that it can slide perpendicularly to the axis m. This makes it possible to set the distance D between the axis n of the pintle 14 and the axis m to any desired value, including zero.
- the inside of the housing 1 is divided into a first region A and a second region B by an imaginary line P that is drawn in the direction in which the pintle 14 slides.
- Those chambers 13 which are travelling through the first region A are placed in communication with a first fluid communication line 21.
- Those chambers 13 which are moving across the second region B communicate with a second fluid communication line 22.
- the first fluid communication line 21 has fluid passages 23, a port 24 extending through the pintle 14, and a fluid inlet/outlet port 25 formed in the housing 1, corresponding to one end of port 24.
- the chambers 13 are in communication with the inside of the barrel 15 via the passages 23.
- One end of the port 24 extends to the outer periphery of the pintle. 14 on the side of the first region A, while the other end extends to the inclined surface 14b of the sliding portion 14a of the pintle 14 that is on the side of the second region B.
- a pressure pocket 27 is formed between the outer periphery of the pintle 14 and the inner surface of the cylinder barrel 15, at one end of port 24, in order to form a third static pressure bearing 26.
- Another pressure pocket 29 is formed between the inclined surface 14b of the pintle 14 and the inner surface of the housing 1, at the other end of the port 24, to form a fourth static pressure bearing 28.
- the pocket 27 is elongated circumferentially, and acts to place all the chambers 13 present in the first region A in communication with the port 24 extending through the pintle.
- the pocket 29 is elongated in the direction in which pintle 14 slides. When pintle 14 is caused to slide, the pocket 29 prevents the port 24 from being disconnected from the fluid inlet/outlet port 25.
- the second fluid communication line 22 has the fluid passages 23 already mentioned, a port 34 extending through the pintle, and a fluid inlet/outlet port 35 formed in the housing 1 at a position corresponding to one end of the port 34.
- the other end of port 34 extends to the outer surface of the pintle 14 on the side of the second region B, while said first end extends to the inclined surface 14c of the sliding portion 14a of the pintle 14 on the side of the first region A.
- a pressure pocket 37 is formed between the pintle 14 and the cylinder barrel 15 to form a third static pressure bearing 36.
- a further pressure pocket 39 is formed between the inclined surface 14c of the pintle 14 and the inner surface of the housing 1 to form a fourth static pressure bearing 38.
- the pockets 37 and 39 are similar in structure to pockets 27 and 29.
- a pressure inlet passage 41 is formed along the axis of each piston 8.
- the fluid pressure within each chamber 13 corresponding to each piston 8 is introduced into the pressure pocket 11 in the corresponding second static pressure bearing 9 via the pressure inlet passage 41.
- the hydraulic pressure within the pocket 11 is introduced into the pressure pockets 7a, 7b in the corresponding first static pressure bearing 3 via fluid passages 42a, 42b formed in the ring 2.
- Restrictors 40a and 40b are disposed in the passages 42a and 42b, respectively.
- the directions and area of the static pressure bearings 3 and 9 are so set that the force F a acting on the ring 2 due to the static pressure of the fluid introduced into the first bearings 3 is identical in magnitude but opposite in sense to the force F b acting on the torque ring due to the static pressure introduced into the second bearings 9.
- the area of the second bearings 9 is set to such a value that the force acting on the piston 8 due to the static pressure applied to the bearing 9 is cancelled by the force working on the piston 8 due to the static pressure of the fluid within the chambers 13.
- the area of the third static pressure bearings 26 and 36 is set to such a value that the force acting on the barrel 15 due to the static pressure introduced into the bearings 26 and 36 is cancelled by the force acting on the barrel 15 due to the static pressure of the fluid within the chambers 13 being present in the corresponding regions A and B.
- the angle at which the surfaces 14b and 14c are inclined is set to such a value that the force acting on the pintle 14 due to the static pressure of the fluid introduced to the bearings 28 and 38 is cancelled by the force acting on the pintle 14 due to the static pressure of the fluid introduced to the third bearings 26 and 36 being present in the regions A and B in opposite relation to the inclined surfaces 14b and 14c on which the bearings 28 and 38 are respectively mounted.
- Referenced by numeral 43 are seal members.
- a control lever 44 is used to slide the pintle 14.
- Each shoe 5 is firmly fixed to the torque ring 2 with a fixing element 45.
- the high pressure fluid is supplied into the chambers 13 being present in the first region A through the first fluid communication line 21.
- the axis n of pintle 14 is brought to a position which is at a given distance D from the axis m of the housing 1.
- the line of action of the force F a acting on the ring 2 due to the static pressure of the fluid introduced in the first bearings 3 rotates in the direction of axis X relatively to the line of force F b acting on the ring 2 due to the static pressure of the fluid introduced in the corresponding second bearings 9 within the first region A.
- the forces F a and F b are identical in magnitude but opposite in direction to each other. Since they act parallelly to each other, they constitute couples. As can be seen from Fig. 4, said coupled induced by F a and F b developed at spaced locations on the ring 2 rotate the ring 2 in the same direction. Therefore, since the ring 2 receives the couples F a , F b directly from the fluid, the ring 2 rotates in the direction indicated by the arrow S.
- the ring 2 When the converter is employed as a hydraulic pump, the ring 2 is rotated by an external force, for example, in the direction indicated by the arrow R. Then, couples of forces F a , F b are set up on ring 2 similarly to the foregoing.
- the input torque applied to the ring 2 is balanced by the couples Fa, F b .
- The, fluid from outside the housing 1 is forced successively into the chambers 13 travelling across the second region B, through the second fluid communication line 22.
- the pressure fluid enters the chambers 13 moving across the first region A, and is then discharged from the housing 1 through the first line 21. In this case, if the pintle 14 slides to its neutral position, the amount of fluid discharged is made zero. This allows the ring 2 to run idle under an hydrostatically balanced condition.
- each first bearing 3 has a pair of pressure pockets 7a and 7b axially neighboring one another.
- the fluid flows out of the corresponding chambers 13 and is distributed to the pressure pockets 7a and 7b via the restrictors 40a and 40b.
- each fluid leakage gap 45b in the bearings 3 that is remoter from the pistons 8 becomes slightly larger than each fluid leakage gap 45a closer to the pistons 8 due to the elastic deformation of the peripheral wall 2a of the ring 2 due to the hydraulic pressure. Consequently, the pressure inside the pocket 7b that is remoter from the pistons 8 becomes lower than the pressure inside the pocket 7a that is closer to each piston 8. As a result, the center of pressure q of each first bearing 3 comes closer to each piston 8 than the geometrical center b, automatically reducing the axial distance between the center of pressure q and the center g of each piston 8.
- the configuration shown in Fig. 10 is derived by rotating the above configuration through 180 ° .
- each fluid leakage gap 45a of the bearings 3 that is remoter from each piston 8 becomes slightly larger than each fluid leakage gap 45b that is closer to each piston by the elastic deformation of the peripheral wall 2a of the ring 2 that is caused by the hydraulic pressure. Consequently, the pressure inside the pocket 7a remoter from each piston 8 becomes lower than the pressure inside the pocket 7b closer to each piston.
- the center of pressure q of each first bearing 3 comes closer to each piston 8 than the geometrical center b.
- the axial gap between the center of pressure q and the center g of each piston 8 is automatically reduced.
- the novel rotary fluid energy converter can be employed either as a hydraulic pump or as a hydraulic motor as mentioned above. In either case, only the hydrostatic pressure of the fluid introduced into the first bearings 3 and the second bearings 9 produces the couples induced by F a and F b on the ring 2. The couples induced by F a and F b are balanced by the input of output torque acting on the ring 2. Hence, the hydrostatic pressure of the fluid can be directly converted into rotary motion of the ring 2, only. Also it is possible to transform the rotary motion of the ring 2 into fluid pressure . Thus, a mechanism for mechanically converting rectilinear motion and rotary motion is entirely dispensed with. Moreover, as already described, the axial distance between the center of pressure of each first bearing and the center of each piston is minimized to thereby prevent undue bending or twisting force from acting on the ring.
- FIG. 13-22 there is shown an alternative embodiment of the energy converter according to the invention.
- This converter is similar to the converter already described in connection with Figs. 1-10, except for the structure of the shoes of the static pressure bearings.
- This converter has the first static pressure bearings 3 which attached shoes 5 to the outer periphery of the torque ring 2 at requisite positions, the shoes 5 being also attached to the tapering surface 4 of the housing 1.
- Each shoe 5 is provided with three pressure pockets 7a, 7b, 7c axially neighboring one another. Hydraulic pressure is introduced into these pockets 7a-7c.
- An odd number of bearings 3 are circumferentially regularly spaced from one another.
- the surrounding portions 5a, 5b, 5c, 5d, 5e that surround the pressure pockets 7a-7c are so shaped that their cross section protrudes toward the tapering surface 4, as shown in Figs. 17-19. this reduces the area with which each shoe 5 is in sliding contact with the tapering surface 4.
- the surrounding portions 5a-5e are formed so as not be to parallel to the direction of rotation X. More specifically, only the surrounding portions 5 a and 5b which are perpendicular to the direction of rotation X are shaped into a rectilinear form.
- the surrounding portions 5c and 5e are shaped like the letter "V".
- the surrounding portion 5d is so shaped as to be oblique to the direction of rotation X. It is to be noted that Figs. 13-16 are basically the same as Figs. 1-4, and the components shown in those figures will not be described herein.
- the hydraulic pressure inside the chambers 13 corresponding to the pistons 8 is directed into the pressure pockets 11 in the corresponding second bearings 9 via the pressure inlet passage 41 formed along the axis of each piston 8.
- the hydraulic pressure inside the pockets 11 is routed into the pressure pockets 7a, 7b, 7c in the corresponding bearings 3 via the fluid passages 42a, 42b, 42c formed in the ring 2.
- These passages 42a-42c cooperate with the pressure pockets 11 to form slide valve elements 50.
- each valve element 50 acts to selectively cut off the supply of the fluid into the pockets 7a, 7b, 7c, making use of the relative movement between each piston 8 and the ring 2 in the direction of the Y axis.
- the pockets 11 are in communication with all the fluid passages 42a, 42b, 42c.
- the passage 42c or 42a remoter from the piston 8 interrupts communication with the pocket 11, as shown in Figs. 21 and 22.
- the restrictors 40a, 40b, 40c are formed in the passages 42a and 42b.
- each first bearing 3 is provided with the pressure pockets 7a, 7b, 7c axially neighboring one another.
- Each slide valve element 50 is provided to selectively interrupt the supply of the fluid into the pockets 7a-7c, making use of the relative movement between each piston 8 and the ring 2 in the direction of the Y axis. Consequently, actions as shown in Figs. 20-22 are obtained.
- each first bearing 3 when the geometrical center b of each first bearing 3 is not displaced from the center g of each piston 8 in the direction of the Y axis as shown in fig. 20, all the fluid communication passages 42a, 42b, 42c are in communication with the pressure pockets 11, so that the pressures inside the pockets 7a, 7b, 7c are equal. Consequently, the point of application q, or center of pressure, of the force Fa acting on the ring 2 due to the static pressure in the first bearings 3 is not displaced at all from the center g of each piston 8 in the direction of the Y axis.
- the distance between the pressure center of each first static pressure bearing and the center of each piston along the Y axis is reduced to a minimum in the same manner as in the converter already described in conjunction with Figs. 1-10.
- This can prevent undue bending or twisting force from acting on the torque ring. Therefore, it is easy to design the structure in such a way that its components are not severely pressed against each other or twisting force does not act on them. Further, it is possible to quite dispense with bearings utilizing the wedging action of oil films relying on the oiliness or viscosity of lubricating oil, or with bearings utilizing the rolling action of balls, rolls, or the like.
- static pressure bearings may be provided enabling using water or other fluid exhibiting a viscosity comparable to that of water without difficulty.
- static pressure bearings are used instead of roller bearings, the machine is not affected by the operation life of roller bearings. This makes it possible to increase the operation life of the machine. In addition, it helps make the machine in smaller size and lightweight.
- the converter can be advantageously used as a hydraulic pump or motor of the variable displacement type.
- the invention is not limited to this scheme.ln addition, as the eccentric position of the pintle is adjustable, the adjusting means is not limited to the foregoing means.
- the pintle may be reciprocated by a hydraulic actuator.
- the cross-sectional shape of the surrounding portions that surround the pressure pockets in the first static pressure bearings is not limited to the shape described above. Where the cross section protrudes as described already, however, shapes of wedge-shaped cross section are formed between the surrounding portions and the tapering surface.
- the converter When the converter operates, fluid enters the wedge-shaped spaces, producing hydrodynamic pressure. This allows the housing and the torque ring to be rotated relatively to each other more smoothly. Since the surrounding portions are so shaped that no portion is parallel to the direction of rotation, the hydrodynamic pressure is generated on every portion of the surrounding portions. Therefore, when the converter runs at high speeds, especially excellent bearing action can be obtained. Obviously, it is possible to fabricate the torque ring 2 and the shoes 5 integral as shown in Fig. 25.
- angle 91 which is half of the angle that the protruding portion of each surrounding portion makes is made larger than the complementary angle e 3 of the cone angle e 2 at the tapering portion of the outer periphery of the torque ring. Then,moulds for the outer periphery of the ring can be removed axially, enhancing the productivity. In other words, by making the gradient of the protruding portion of the cross section of the surrounding portion not larger than the gradient of the cone formed by the inner surface of the housing, mould release is facilitated.
- the number of the pistons is not limited to the number in the illustrated embodiment.
- the working fluid is not limited to liquids. For example, it can be a gas such as air.
- the novel rotary fluid energy converter is constructed as described thus far, it can act either as a pump or as a motor without using a mechanism for mechanically converting rectilinear or rotary motion into another form of motion. Further, it in- dudes a simple structure which does not use valve element or the like at all but which can effectively prevent couple from occurring on the torque ring on a position off the axis of rotation, which would otherwise be caused by the presence of axial distance between the pressure center of each first static pressure bearing and the center of each piston.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Hydraulic Motors (AREA)
- Reciprocating Pumps (AREA)
Description
- The present invention relates to a rotary fluid energy converter that is used either as a hydraulic pump or as a hydraulic motor of the hydrostatic type.
- A conventional rotary energy converter of this kind is employed as a hydrostatic hydraulic pump or motor and always uses mechanisms, such as cam mechanisms and linkages, for converting rotary power applied to its input shaft into rectilinear motion of a piston, plunger, or the like and for converting such rectilinear motion of the piston into rotary motion of its output shaft. Since its components are pressed against each other or a twisting force is applied to some components, the converter must employ bearings that make use of either the wedging action of oil films utilizing oiliness or viscosity of lubricating oil or the rolling action of balls, rollers, or the like. Therefore, an oil having an appropriate viscosity is required to be used as working fluid. If water or other fluid with a viscosity comparable to water is used as working fluid, it will be difficult to operate the convertor smoothly. This makes the operation life of the machine quite short. Thus, working fluids that can be used are limited to some kinds. If roller bearings are used, the operation life of the whole machine depends on the operation life of these bearings, making it difficult to enhance the durability. Moreover, roller bearings are relatively bulky. This renders it difficult to make the machine in smaller size or lightweight.
- In recent years, an almost ideally efficient fluid energy converter operating on quite different principles from the prior art technique described above was developed (see Japanese laid open patent specification No. 77179/1983 and EP-A1 0 078 513).
- Scecifically, this known converter comprises a housing having a tapering surface in its inner surface, a torque ring which is closely held against the tapering surface of the housing via first static pressure bearings disposed circumferentially regularly spaced from each other, said ring having flat surfaces corresponding to the first bearings on its inner surface, a plurality of pistons disposed on the inner side of the ring and having their front ends connected to the flat surfaces of the ring via second static pressure bearings, a cylinder barrel for slidably supporting the bottom ends of the pistons, a pintle being slidable perpendicularly to the axis of the housing and supposing the barrel, chambers formed between each piston and the barrel whose volume alternately increases and decreases during rotation of the housing relatively to the ring, a pair of fluid communication passages for communicating with the chambers whose volumes are increasing and decreasing, and fluid passages for introducing fluid from the chambers into the first and second bearings.
- Consequently, the static pressures of the fluid introduced into the first and second bearings develop a couple of forces about the axis of rotation on the torque ring.
- In each first static pressure bearing having a single pressure pocket, the center of pressure of each bearing is maintained at a certain position and so the ring is submitted to another couple of forces being produced in a position being off the axis of rotation. This structure is now described by referring to Figs. 11 and 12, where the static pressure in each first static pressure bearing a produces a force Fa that acts along a line of action Ls. This line La passes across the center of pressure (geometrical center) b of the bearing a, and every line of action La focus toward a point d on the axis m of both the housing c and the torque ring k. The static pressure in each second static pressure bearing e produces a force Fb that acts along a line of action Lb. Every such line of action Lb, (median lines g of the pistons f), focus toward a point i on the axis n of the pintle h.
- Therefore,knowing that the inner surface j of the housing c tapers, the torque ring k rotating relatively to the housing c and the axis n of the pintle h being displaced from the axis m of the housing c, the center g of the pintle f periodically moves away from the pressure center (geometrical center) b of the bearing a,while following an elliptic orbit p as shown in Fig. 12. In this case, the movement of the center g relative to the pressure center b along the axis X is needed to produce a couple of forces about the axis of rotation on the ring k. However, displacement along axis Y bends or twists the ring k. This can impair the features of this system, i.e., excellent durability and the ability to run smoothly and efficiently.
- It is an object of the present invention to provide an energy converter equipped with a simple structure which effectively prevents a couple from occurring in a position being off the axis of rotation, which would otherwise be produced by the axial deviation of the pressure center of each first static pressure bearing from the center of each piston.
- This is achieved by a converter characterized in that it further comprises : at least two axially adjacent pressure pockets formed in each of the first static means for automatically selectively distributing pressure fluid into said pressure pockets so that when the median axis of the piston is displaced relatively to the median axis of the corresponding pressure bearing the pressure pockets being remoter from said median axis of the piston have a pressure at least inferior as compared to the pressure pockets being closer to said axis.
- In one embodiment of the invention, said means for automatically selectively distributing pressure fluid into the pressure pockets are constituted of restrictors through which the fluid flowing out of the chamber is distributed to the corresponding pressure pockets.
- In another embodiment of the invention, said means for automatically selectively distributing pressure fluid into the pressure pockets are constituted of slide valve elements for selectively intermitting the supply of fluid into said remoter pressure pockets by making use of the axial relative movement between each piston and the torque ring.
- In the structure constructed according to the abovementioned first embodiment, when the center of each piston axially moves away from the geometrical center of each first bearing, each fluid leakage gap of the bearings that is remoter from each piston becomes slightly larger than each fluid leakage gap of the bearings that is closer to each piston by the elastic deformation of the torque ring due to hydraulic pressure, so that the pressure inside each pressure pocket remoter from each piston becomes lower than the pressure inside each pressure pocket closer to each piston. As a result, the center of pressure of each first bearing comes closer to each corresponding piston than the geometrical center. Thus, the axial distance separating the center of pressure from the center of each piston is automatically reduced.
- In the structure constructed according to the abovementioned second embodiment, when the center of each piston axially moves away from the geometrical center of each first bearing, the switching action of each slide valve element cuts off the supply of pressure fluid into some pressure pockets, so that the center of pressure of each first bearing comes closer to the piston than the geometrical center. As a result, the axial gap between the center of pressure and the center of each piston is automatically reduced.
- Other objects and features of the invention will appear in the course of description that follows and in the corresponding drawings in which :
- Fig. 1 is a front cross section view in elevation of an energy converter according to the invention.
- Fig. 2 is a cross-sectional view taken along line II-II of Fig. 1.
- Fig. 3 is a cross-sectional view taken along line III-III of Fig. 1.
- Fig. 4 is a cross-sectional view taken along line IV-IV of Fig. 3.
- Fig. 5 is an enlarged plan view of the pressure pockets in one of said first static pressure bearings of the converter shown in fig. 1.
- Fig. 6 is a cross-sectional view taken along line VI-VI of Fig. 5.
- Fig. 7 is a cross-sectional view taken along line VII-VII of Fig. 5.
- Figs. 8-10 are fragmentary views for illustrating the operation of the converter shown in Fig. 1.
- Fig. 11 is a partially cross-sectional view of a convention converter.
- Fig. 12 is a fragmentary plan view of one of said first static pressure bearings of the converter shown in Fig. 11.
- Fig. 13 is a front cross section view in elevation of another embodiment of the energy converter according to the invention.
- Fig. 14 is a cross-sectional view taken along line II-II of Fig. 13.
- Fig. 15 is a cross-sectional view taken along line III-III of Fig.13.
- Fig. 16 is a cross-sectional view taken along line IV-IV of Fig. 15.
- Fig. 17 is an enlarged plan view of the pressure pocket of one of the static pressure bearings of the converter shown in Fig. 13.
- Fig. 18 is a cross-sectional view taken along line VI-VI of Fig. 17.
- Fig. 19 is a view in perspective of the pressure pockets shown in Fig. 13.
- Figs. 20-22 are fragmentary views for illustrating the operation of the converter shown in Fig. 13.
- Fig. 23 is a partially cross-sectional view of a conventional converter.
- Fig. 24 is a fragmentary plan view of one first static pressure bearing shown in fig. 23 ; and
- Fig. 25 is a diagram for showing a further energy converter according to the invention.
- Referring to Figs. 1-10, there is shown an energy converter according to the invention. This converter comprises a cylindrical housing 1 with a bottom portion, and a
torque ring 2 is rotatably and closely held on the inner surface of the housing 1 via firststatic pressure bearings 3. The housing 1 is provided with an opening la at one of its ends. The inner surface of the housing has a surface 4 tapering toward the opening la, and thering 2 is in contact with this tapering surface 4. Thering 2 is shaped like a cup and has aperipheral wall 2a presenting the same apical angle as the tapering surface 4. A rotatingshaft 6 is formed integrally with thering 2 and protrudes from one of its axial ends. The front end portion of theshaft 6 extends outwardly from the housing 1 through the opening la. Thefirst bearings 3 rigidly compriseshoes 5 being rigidly fixed to the outer surface of thering 2 at required positions, eachshoe 5 being pressed on the tapering surface 4 of the housing 1. Eachshoe 5 is provided with a pair of pressure pockets, 7a and 7b, axially neighboring one another. Hydraulic pressure is introduced into thepockets bearings 3 are circumferentially regularly spaced apart from one another. Thepockets shoe 5 is surrounded by surroundingportions shoe 5 is in sliding contact with the tapering surface 4 by a small area. In addition, the surroundingportions 5a-5c are so shaped that they are not parallel to the axis of rotation X. - More specifically, only the surrounding
portion 5a perpendicular to the axis of rotation X is straight in shape. The surroundingportion 5b is shaped like the letter "V". The surroundingportion 5c is shaped in a zigzag manner. The inner surface of thetorque ring 2 hasflat surfaces 2c at positions corresponding to thebearings 3. - The
pistons 8 are disposed at positions corresponding to the innerflat surfaces 2c. The front ends 8a of thepistons 8 are pressed against their correspondingsurfaces 2c via secondstatic pressure bearings 9. Thebearings 9 are made flat so that the front ends 8a of thepistons 8 come into close contact with theircorresponding surfaces 2c. Each of thefront end 8a has apressure pocket 11 into which hydraulic pressure is introduced. The base end of eachpiston 8 is held by apiston retainer 12. Achamber 13 is formed between theretainer 12 and thepiston 8 for the admission of fluid. - The
piston retainer 12 consists of apintle 14 having a slidingportion 14a cooperating with anannular cylinder barrel 15. The slidingportion 14a is supported on the housing 1. Thepintle 14 can rotate about an axis n being parallel to the axis m of both the housing 1 and thetorque ring 2. Thebarrel 15 is rotatably fitted over the outer periphery of thepintle 14. Thebarrel 15 is provided withcylinders 16 which are regularly circumferentially spaced apart from one another and are arranged radially. The axis of eachcylinder 16 is substantially perpendicular to the outer surface of thepintle 14. Thepistons 8 are fitted in thecylinders 16 so as to be slidable. The base surface 8b of eachpiston 8 and the inner surface of eachcylinder 16 form theaforementioned chamber 13. Thebarrel 15 is connected to thetorque ring 2 via anOldham coupling 20 or similar, so that the barrel can rotate at the same angular velocity as thering 2. - The
pintle 14 takes the form of a truncated cone whose outer surface makes an apical angle substantially equal to the apical angle formed by theperipheral wall 2a of thering 2. Thepistons 8 are so held that they can move back and forth perpendicularly to theperipheral wall 2a of thering 2. The slidingportion 14a of thepintle 14 is shaped as a longitudinally elongated block with a trapezoidal cross section. The slidingportion 14a is slidably fitted in atrapezoidal groove 19 formed in the housing 1. In other words, thepintle 14 is held in such a way that it can slide perpendicularly to the axis m. This makes it possible to set the distance D between the axis n of thepintle 14 and the axis m to any desired value, including zero. - As shown in Fig. 2, the inside of the housing 1 is divided into a first region A and a second region B by an imaginary line P that is drawn in the direction in which the
pintle 14 slides. Thosechambers 13 which are travelling through the first region A are placed in communication with a firstfluid communication line 21. Thosechambers 13 which are moving across the second region B communicate with a secondfluid communication line 22. - The first
fluid communication line 21 hasfluid passages 23, aport 24 extending through thepintle 14, and a fluid inlet/outlet port 25 formed in the housing 1, corresponding to one end ofport 24. Thechambers 13 are in communication with the inside of thebarrel 15 via thepassages 23. One end of theport 24 extends to the outer periphery of the pintle. 14 on the side of the first region A, while the other end extends to theinclined surface 14b of the slidingportion 14a of thepintle 14 that is on the side of the second region B.A pressure pocket 27 is formed between the outer periphery of thepintle 14 and the inner surface of thecylinder barrel 15, at one end ofport 24, in order to form a third static pressure bearing 26. Anotherpressure pocket 29 is formed between theinclined surface 14b of thepintle 14 and the inner surface of the housing 1, at the other end of theport 24, to form a fourth static pressure bearing 28. Thepocket 27 is elongated circumferentially, and acts to place all thechambers 13 present in the first region A in communication with theport 24 extending through the pintle. Thepocket 29 is elongated in the direction in which pintle 14 slides. Whenpintle 14 is caused to slide, thepocket 29 prevents theport 24 from being disconnected from the fluid inlet/outlet port 25. - The second
fluid communication line 22 has thefluid passages 23 already mentioned, aport 34 extending through the pintle, and a fluid inlet/outlet port 35 formed in the housing 1 at a position corresponding to one end of theport 34. The other end ofport 34 extends to the outer surface of thepintle 14 on the side of the second region B, while said first end extends to theinclined surface 14c of the slidingportion 14a of thepintle 14 on the side of the first region A. At the other end of theport 34, apressure pocket 37 is formed between thepintle 14 and thecylinder barrel 15 to form a third static pressure bearing 36. At said one end of theport 34, afurther pressure pocket 39 is formed between theinclined surface 14c of thepintle 14 and the inner surface of the housing 1 to form a fourth static pressure bearing 38. Thepockets pockets - A
pressure inlet passage 41 is formed along the axis of eachpiston 8. The fluid pressure within eachchamber 13 corresponding to eachpiston 8 is introduced into thepressure pocket 11 in the corresponding second static pressure bearing 9 via thepressure inlet passage 41. The hydraulic pressure within thepocket 11 is introduced into the pressure pockets 7a, 7b in the corresponding first static pressure bearing 3 viafluid passages ring 2.Restrictors passages - The directions and area of the
static pressure bearings ring 2 due to the static pressure of the fluid introduced into thefirst bearings 3 is identical in magnitude but opposite in sense to the force Fb acting on the torque ring due to the static pressure introduced into thesecond bearings 9. The area of thesecond bearings 9 is set to such a value that the force acting on thepiston 8 due to the static pressure applied to thebearing 9 is cancelled by the force working on thepiston 8 due to the static pressure of the fluid within thechambers 13. Moreover, the area of the thirdstatic pressure bearings barrel 15 due to the static pressure introduced into thebearings barrel 15 due to the static pressure of the fluid within thechambers 13 being present in the corresponding regions A and B. The angle at which thesurfaces pintle 14 due to the static pressure of the fluid introduced to thebearings pintle 14 due to the static pressure of the fluid introduced to thethird bearings inclined surfaces bearings control lever 44 is used to slide thepintle 14. Eachshoe 5 is firmly fixed to thetorque ring 2 with a fixingelement 45. - The operation of the illustrated converter is now described. When it is used as a hydraulic motor, the high pressure fluid is supplied into the
chambers 13 being present in the first region A through the firstfluid communication line 21. Then, as shown, the axis n ofpintle 14 is brought to a position which is at a given distance D from the axis m of the housing 1. Thus, as shown in Fig. 4, the line of action of the force Fa acting on thering 2 due to the static pressure of the fluid introduced in thefirst bearings 3 rotates in the direction of axis X relatively to the line of force Fb acting on thering 2 due to the static pressure of the fluid introduced in the correspondingsecond bearings 9 within the first region A. The forces Fa and Fb are identical in magnitude but opposite in direction to each other. Since they act parallelly to each other, they constitute couples. As can be seen from Fig. 4, said coupled induced by Fa and Fb developed at spaced locations on thering 2 rotate thering 2 in the same direction. Therefore, since thering 2 receives the couples Fa, Fb directly from the fluid, thering 2 rotates in the direction indicated by the arrow S. - It is now assumed for the illustrated embodiment that the magnitude of the couples induced by Fa and Fb is equal to F and that the distances of the lines of actions are 11, 12, 1 a. Then, the moment M acting on the
ring 2 is given byring 2 to rotate relatively to the housing 1. In this case, as thering 2 rotates the volume of eachchamber 13 present in the first region A gradually increases, while the volume of eachchamber 13 present in the second region B gradually decreases. Accordingly, the high pressure fluid successively flows into thechambers 13 which are travelling across first region A, throughfirst line 21. After doing work, the fluid flows out of saidchambers 13 moving across the second region B and is discharged from the housing 1 throughsecond tine 22. - Under this condition, if the
pintle 14 is slided into its neutral position where the axis n coincides with the axis m of the housing 1, then the distances 11, 12, 13 of the lines of action of the forces Fa and Fb are all reduced to zero. As a result, the moment acting onring 2 disappears, making the output zero. If thepintle 14 is moved in the direction opposite to the direction shown across its neutral position, the distances 11, 12, 13 of the lines of action of the couples induced by Fa and Fb assume negative values and act reversely onring 2. - When the converter is employed as a hydraulic pump, the
ring 2 is rotated by an external force, for example, in the direction indicated by the arrow R. Then, couples of forces Fa, Fb are set up onring 2 similarly to the foregoing. The input torque applied to thering 2 is balanced by the couples Fa, Fb. The, fluid from outside the housing 1 is forced successively into thechambers 13 travelling across the second region B, through the secondfluid communication line 22. The pressure fluid enters thechambers 13 moving across the first region A, and is then discharged from the housing 1 through thefirst line 21. In this case, if thepintle 14 slides to its neutral position, the amount of fluid discharged is made zero. This allows thering 2 to run idle under an hydrostatically balanced condition. If thepintle 14 is moved in the direction opposite to the direction shown across the neutral position, then couples induced by Fa and Fbbalanced by the input torque are produced in the second region. Then, the high pressure fluid is delivered out of the housing 1 via thesecond line 22. - As the
ring 2 is rotated relatively to the housing 1, the geometrical center b of eachfirst bearing 3 and the center g of eachpiston 8 are shifted along the Y axis, whether the converter is used as a motor or a pump, as mentioned above. In this fluid energy converter, eachfirst bearing 3 has a pair ofpressure pockets chambers 13 and is distributed to the pressure pockets 7a and 7b via therestrictors - Referring to Fig. 8, when the geometrical center b of each
first bearing 3 is not displaced with respect to the center g of eachpiston 8 in the direction of the Y axis, the pressures inside thepockets ring 2 due to the static pressure inside thebearings 3 is not displaced at all from the center g of eachpiston 8 in the direction of the Y axis. - Referring to Fig. 9, when the center g of each
piston 8 is axially displaced from the geometrical center b of eachfirst bearing 3, eachfluid leakage gap 45b in thebearings 3 that is remoter from thepistons 8 becomes slightly larger than eachfluid leakage gap 45a closer to thepistons 8 due to the elastic deformation of theperipheral wall 2a of thering 2 due to the hydraulic pressure. Consequently, the pressure inside thepocket 7b that is remoter from thepistons 8 becomes lower than the pressure inside thepocket 7a that is closer to eachpiston 8. As a result, the center of pressure q of eachfirst bearing 3 comes closer to eachpiston 8 than the geometrical center b, automatically reducing the axial distance between the center of pressure q and the center g of eachpiston 8. - The configuration shown in Fig. 10 is derived by rotating the above configuration through 180°. Specifically, when the center g of each
piston 8 is displaced from the geometrical center b of eachfirst bearing 3 in the axial direction opposite to the foregoing direction, eachfluid leakage gap 45a of thebearings 3 that is remoter from eachpiston 8 becomes slightly larger than eachfluid leakage gap 45b that is closer to each piston by the elastic deformation of theperipheral wall 2a of thering 2 that is caused by the hydraulic pressure. Consequently, the pressure inside thepocket 7a remoter from eachpiston 8 becomes lower than the pressure inside thepocket 7b closer to each piston. As a result, the center of pressure q of eachfirst bearing 3 comes closer to eachpiston 8 than the geometrical center b. Also, the axial gap between the center of pressure q and the center g of eachpiston 8 is automatically reduced. - The novel rotary fluid energy converter can be employed either as a hydraulic pump or as a hydraulic motor as mentioned above. In either case, only the hydrostatic pressure of the fluid introduced into the
first bearings 3 and thesecond bearings 9 produces the couples induced by Fa and Fb on thering 2. The couples induced by Fa and Fb are balanced by the input of output torque acting on thering 2. Hence, the hydrostatic pressure of the fluid can be directly converted into rotary motion of thering 2, only. Also it is possible to transform the rotary motion of thering 2 into fluid pressure . Thus, a mechanism for mechanically converting rectilinear motion and rotary motion is entirely dispensed with. Moreover, as already described, the axial distance between the center of pressure of each first bearing and the center of each piston is minimized to thereby prevent undue bending or twisting force from acting on the ring. - Referring now to Figs. 13-22, there is shown an alternative embodiment of the energy converter according to the invention. This converter is similar to the converter already described in connection with Figs. 1-10, except for the structure of the shoes of the static pressure bearings. This converter has the first
static pressure bearings 3 which attachedshoes 5 to the outer periphery of thetorque ring 2 at requisite positions, theshoes 5 being also attached to the tapering surface 4 of the housing 1. Eachshoe 5 is provided with threepressure pockets pockets 7a-7c. An odd number ofbearings 3 are circumferentially regularly spaced from one another. The surroundingportions shoe 5 is in sliding contact with the tapering surface 4. Also, the surroundingportions 5a-5e are formed so as not be to parallel to the direction of rotation X. More specifically, only the surroundingportions portions portion 5d is so shaped as to be oblique to the direction of rotation X. It is to be noted that Figs. 13-16 are basically the same as Figs. 1-4, and the components shown in those figures will not be described herein. - In this structure, the hydraulic pressure inside the
chambers 13 corresponding to thepistons 8 is directed into the pressure pockets 11 in the correspondingsecond bearings 9 via thepressure inlet passage 41 formed along the axis of eachpiston 8. The hydraulic pressure inside thepockets 11 is routed into the pressure pockets 7a, 7b, 7c in thecorresponding bearings 3 via thefluid passages ring 2. Thesepassages 42a-42c cooperate with the pressure pockets 11 to formslide valve elements 50. - Referring to Figs. 20-22, each
valve element 50 acts to selectively cut off the supply of the fluid into thepockets piston 8 and thering 2 in the direction of the Y axis. When the distance between the geometrical center b of eachfirst bearing 3 and the center g of eachpiston 8 in the direction of the Y axis keeps within a given range, thepockets 11 are in communication with all thefluid passages passage piston 8 interrupts communication with thepocket 11, as shown in Figs. 21 and 22. Therestrictors passages - As described above, as the
ring 2 is rotated rela- fively to the housing 1, the geometrical center b of eachfirst bearing 3 and the center g of eachpiston 8 are moved in the direction of the Y axis, whether the converter is used as a motor or as a pump. In this fluid energy converter, eachfirst bearing 3 is provided with the pressure pockets 7a, 7b, 7c axially neighboring one another. Eachslide valve element 50 is provided to selectively interrupt the supply of the fluid into thepockets 7a-7c, making use of the relative movement between eachpiston 8 and thering 2 in the direction of the Y axis. Consequently, actions as shown in Figs. 20-22 are obtained. Specifically, when the geometrical center b of eachfirst bearing 3 is not displaced from the center g of eachpiston 8 in the direction of the Y axis as shown in fig. 20, all thefluid communication passages pockets ring 2 due to the static pressure in thefirst bearings 3 is not displaced at all from the center g of eachpiston 8 in the direction of the Y axis. When the center g of thepiston 8 is displaced only slightly in the direction of the Y axis but displaced considerably to the vicinities of points t and u shown in fig. 24 in the direction of the X axis, thefluid passages pockets 11, leaving only thefluid passages 42b in communication with thepockets 11. The result is that the center g of eachpiston 8 is axially displaced only slightly from the point of application q, or the center of pressure, of the force Fa acting on thering 2. - When the center g of each
piston 8 is displaced from the geometrical center b of eachfirst bearing 3 in the direction of the Y axis as shown in Fig. 21, thepassage 42c remoter from thepiston 8 is not in communication with thepocket 11. This permits pressure fluid to be supplied only into twopressure pockets bearings 3 which are closer to thepiston 8. As a result, the center of pressure q of thefirst bearing 3 comes closer to thepiston 8 than the geometrical center b. In this way, the axial distance between the center of pressure q and the center g of eachpiston 8 is automatically reduced. When this configuration is rotated through 180°, the configuration shown in Fig. 22 is derived. - Referring to Fig. 22, when the center g of each
piston 8 is axially displaced from the geometrical center b of eachfirst bearing 3 in the direction opposite to the foregoing direction, thepassage 42a remoter from thepiston 8 is disconnected from thepocket 11. Hence, pressure fluid is supplied only into the twopressure pockets bearings 3 which are closer to thepiston 8. As a result, the center of pressure q of eachfirst bearing 3 comes closer to eachpiston 8 than the geometrical center b. Also in this case, the gap between the center of pressure q and the center g of the piston is automatically reduced. Immediately after thefluid passage bearing 3 is not yet greatly displaced from the center g of thepiston 8, there arise the possibility that the center of pressure q becomes remoter from the geometrical center b than the center g of thepiston 8. If the pressure center q moves past the center g of thepiston 8 and across the geometrical center in the direction of the Y axis, thefluid leakage gap 45c or 45a to which the pressure center q has come closer becomes slightly larger due to the elastic deformation of theperipheral wall 2a of thering 2. Then, the pressure inside thepressure pocket piston 8. In Figs. 20-22, Fa, Fb, and Fc schematically indicate forces acting on thering 2 because of the pressures inside thepockets - Since the converter is designed as described above, the distance between the pressure center of each first static pressure bearing and the center of each piston along the Y axis is reduced to a minimum in the same manner as in the converter already described in conjunction with Figs. 1-10. This can prevent undue bending or twisting force from acting on the torque ring. Therefore, it is easy to design the structure in such a way that its components are not severely pressed against each other or twisting force does not act on them. Further, it is possible to quite dispense with bearings utilizing the wedging action of oil films relying on the oiliness or viscosity of lubricating oil, or with bearings utilizing the rolling action of balls, rolls, or the like. Moreover, adequate static pressure bearings may be provided enabling using water or other fluid exhibiting a viscosity comparable to that of water without difficulty. Also, when static pressure bearings are used instead of roller bearings, the machine is not affected by the operation life of roller bearings. This makes it possible to increase the operation life of the machine. In addition, it helps make the machine in smaller size and lightweight.
- When the eccentric position of the pintle relative to the axis of the housing is adjusted as in the illustrated embodiment, the converter can be advantageously used as a hydraulic pump or motor of the variable displacement type. Of course, the invention is not limited to this scheme.ln addition, as the eccentric position of the pintle is adjustable, the adjusting means is not limited to the foregoing means. For instance, the pintle may be reciprocated by a hydraulic actuator.
- Furthermore, the cross-sectional shape of the surrounding portions that surround the pressure pockets in the first static pressure bearings is not limited to the shape described above. Where the cross section protrudes as described already, however, shapes of wedge-shaped cross section are formed between the surrounding portions and the tapering surface. When the converter operates, fluid enters the wedge-shaped spaces, producing hydrodynamic pressure. This allows the housing and the torque ring to be rotated relatively to each other more smoothly. Since the surrounding portions are so shaped that no portion is parallel to the direction of rotation, the hydrodynamic pressure is generated on every portion of the surrounding portions. Therefore, when the converter runs at high speeds, especially excellent bearing action can be obtained. Obviously, it is possible to fabricate the
torque ring 2 and theshoes 5 integral as shown in Fig. 25. When thering 2 and theshoes 5 are integrally molded, angle 91 which is half of the angle that the protruding portion of each surrounding portion makes is made larger than the complementary angle e3 of the cone angle e2 at the tapering portion of the outer periphery of the torque ring. Then,moulds for the outer periphery of the ring can be removed axially, enhancing the productivity. In other words, by making the gradient of the protruding portion of the cross section of the surrounding portion not larger than the gradient of the cone formed by the inner surface of the housing, mould release is facilitated. Additionally, the number of the pistons is not limited to the number in the illustrated embodiment. The working fluid is not limited to liquids. For example, it can be a gas such as air. - Since the novel rotary fluid energy converter is constructed as described thus far, it can act either as a pump or as a motor without using a mechanism for mechanically converting rectilinear or rotary motion into another form of motion. Further, it in- dudes a simple structure which does not use valve element or the like at all but which can effectively prevent couple from occurring on the torque ring on a position off the axis of rotation, which would otherwise be caused by the presence of axial distance between the pressure center of each first static pressure bearing and the center of each piston.
Claims (6)
characterized in that it further comprises : at least two axially adjacent pressure pockets (7a, 7b ; 7a, 7b, 7c) formed in each of the first static pressure bearings (3) ; and
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP19860400385 EP0234133B1 (en) | 1986-02-24 | 1986-02-24 | Rotary fluid energy converter |
DE8686400385T DE3665753D1 (en) | 1986-02-24 | 1986-02-24 | Rotary fluid energy converter |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP19860400385 EP0234133B1 (en) | 1986-02-24 | 1986-02-24 | Rotary fluid energy converter |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0234133A1 EP0234133A1 (en) | 1987-09-02 |
EP0234133B1 true EP0234133B1 (en) | 1989-09-20 |
Family
ID=8196274
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19860400385 Expired EP0234133B1 (en) | 1986-02-24 | 1986-02-24 | Rotary fluid energy converter |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0234133B1 (en) |
DE (1) | DE3665753D1 (en) |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2416772A1 (en) * | 1974-04-05 | 1975-10-09 | Voith Getriebe Kg | Pump with radial piston rotor on ported shaft - has piston motion controlled by eccentrically rotating ring coupled to drive shaft |
JPS5877179A (en) * | 1981-10-31 | 1983-05-10 | Shimadzu Corp | Rotary type fluid energy converter |
-
1986
- 1986-02-24 DE DE8686400385T patent/DE3665753D1/en not_active Expired
- 1986-02-24 EP EP19860400385 patent/EP0234133B1/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
DE3665753D1 (en) | 1989-10-26 |
EP0234133A1 (en) | 1987-09-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3557661A (en) | Fluid motor | |
SE510066C2 (en) | Oil-free screw rotor machine, the bearings of which are lubricated with an aqueous liquid | |
EP0078513B1 (en) | Rotary fluid energy translating device | |
GB2129063A (en) | A radial bearing in a swash plate fluid machine | |
EP1519006A1 (en) | Swash plate type hydraulic pump or motor | |
US20110268596A1 (en) | Fluid device with flexible ring | |
KR0146954B1 (en) | Scroll type fluid displacement apparatus | |
US4443166A (en) | Scroll fluid apparatus with an arcuate recess adjacent the stationary wrap | |
KR20130142126A (en) | Fluid device with pressurized roll pockets | |
EP0234133B1 (en) | Rotary fluid energy converter | |
EP0234631B1 (en) | Hydromotor | |
KR100962750B1 (en) | Rotating piston machine | |
US4426914A (en) | Axial piston pump | |
EP0120058A1 (en) | Double vane pump | |
US20050036897A1 (en) | Rotary vane pump seal | |
US4715266A (en) | Rotary fluid energy converter | |
JP2921788B2 (en) | Rotary hydraulic transformer | |
US4756676A (en) | Gerotor motor with valving in gerotor star | |
US10082028B2 (en) | Rotary volumetric machine with three pistons | |
EP0235468B1 (en) | Servomechanism | |
KR890000430B1 (en) | Rotary type fluid energy converter | |
US4537562A (en) | Pump | |
JP2528999B2 (en) | Rotary fluid energy converter | |
JP2610303B2 (en) | Variable displacement vane pump | |
US4782737A (en) | Control pintle including a thrust member for a radial flow device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE FR GB IT |
|
17P | Request for examination filed |
Effective date: 19870930 |
|
17Q | First examination report despatched |
Effective date: 19880816 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): DE FR GB IT |
|
ITF | It: translation for a ep patent filed |
Owner name: JACOBACCI & PERANI S.P.A. |
|
REF | Corresponds to: |
Ref document number: 3665753 Country of ref document: DE Date of ref document: 19891026 |
|
ET | Fr: translation filed | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 19920123 Year of fee payment: 7 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19920214 Year of fee payment: 7 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 19920227 Year of fee payment: 7 |
|
ITTA | It: last paid annual fee | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19930224 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19930224 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19931029 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19931103 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED. Effective date: 20050224 |