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GB2056565A - Valve driving fluid operated actuator - Google Patents

Valve driving fluid operated actuator Download PDF

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Publication number
GB2056565A
GB2056565A GB8018235A GB8018235A GB2056565A GB 2056565 A GB2056565 A GB 2056565A GB 8018235 A GB8018235 A GB 8018235A GB 8018235 A GB8018235 A GB 8018235A GB 2056565 A GB2056565 A GB 2056565A
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GB
United Kingdom
Prior art keywords
piston rod
piston
cylinder
valve
driving apparatus
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.)
Granted
Application number
GB8018235A
Other versions
GB2056565B (en
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.)
Kitz Corp
Original Assignee
Kitz Corp
Kitazawa Valve Co Ltd
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
Priority claimed from JP1979078108U external-priority patent/JPS6214461Y2/ja
Priority claimed from JP7811179U external-priority patent/JPS55177572U/ja
Priority claimed from JP1979078109U external-priority patent/JPS6141011Y2/ja
Priority claimed from JP1979078107U external-priority patent/JPS594217Y2/en
Priority claimed from JP7811079U external-priority patent/JPS55177504U/ja
Application filed by Kitz Corp, Kitazawa Valve Co Ltd filed Critical Kitz Corp
Publication of GB2056565A publication Critical patent/GB2056565A/en
Application granted granted Critical
Publication of GB2056565B publication Critical patent/GB2056565B/en
Expired legal-status Critical Current

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/02Mechanical layout characterised by the means for converting the movement of the fluid-actuated element into movement of the finally-operated member
    • F15B15/06Mechanical layout characterised by the means for converting the movement of the fluid-actuated element into movement of the finally-operated member for mechanically converting rectilinear movement into non- rectilinear movement
    • F15B15/066Mechanical layout characterised by the means for converting the movement of the fluid-actuated element into movement of the finally-operated member for mechanically converting rectilinear movement into non- rectilinear movement the motor being of the scotch yoke type

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Lift Valve (AREA)
  • Mechanically-Actuated Valves (AREA)
  • Fluid-Driven Valves (AREA)

Abstract

An actuator comprises a casing proper (26) provided in the interior thereof with a movement conversion- transmission mechanism (30), a piston and cylinder assembly (34) freely detachably fixed to one end of the casing (26), and a supporting device (33) for the piston rod of the assembly (34), the device 33 being freely detachably fixed to the other end of the casing. The actuator can be adapted to the operation of different sizes and kinds of valves merely by the replacement of the assembly (34) and device (33) while using the same casing 26. The actuator is provided with cylindrical bearing members (50, 51) for the piston rod (15) and a rotary driving shaft (21) for coupling to a valve. The scotch-yoke form of conversion mechanism shown includes cylindrical bearing members (54) on pins (17) carried by the piston rod and engageable with the yokes (18). A thrust bearing member (68) is disposed between one end of a compression coil spring (24) (for returning the piston and pistod rod) and a box cover (45) and/or between the other end of the spring and a spring holder (25). <IMAGE>

Description

SPECIFICATION Valve driving apparatus The present invention relates to a valve driving apparatus provided on a valve such as a ball valve, butterfly valve, plug valve, gate valve, etc. and adapted to cause a valve stem to be rotated to thereby open and shut the valve.
There have heretofore been known two kinds of valve driving apparatuses, one of which is a doubleacting cylinder type (including a double-acting twocylinder type) valve driving apparatus utilising as a power source a gas such as compressed and pressurised air, nitrogen, etc. or a liquid such as pressurised air, nitrogen, etc. or a liquid such as pressurised oil etc. (hereinafter referred to totally as "pressurised fluid") and the other of which is a spring-return type valve driving apparatus provided with a reciprocating cylinder and a compression coil spring extended to thereby cause a piston to be moved to the original position by means of its restoring force after being compressed by the action of the reciprocating cylinder.The apparatus of either type is provided with a movement conversiontransmission mechanism for converting the reciprocating movement of a piston rod within the cylinder into a rotating movement and at the same time transmitting the rotating movement to a driving shaft provided on the valve stem.
In the continuously reciprocating movements of the piston and the piston rod of the valve driving apparatus, there gives rise to an adverse phenomenon that the piston rod itself is given a rotating movement relative to the center axis thereof due to an eddy current of the pressurised fluid introduced into the cylinder or frictional displacements in bearing portions for the piston rod or, in the case of the spring-return type valve driving apparatus, due to a twisting action of the compression coil spring to be compressed and extended.Particularly when a scotch yoke type movement conversiontransmission mechanism is used and openings of the scotch yokes are disposed at right angles relative to the piston rod, the piston rod and pins fixed onto the piston rod are rotated in the direction of the width of the piston rod and, therefore, the parallel relation between the pins and the driving shaft of the valve driving apparatus cannot be maintained, with the result that the pins are out of engagement with the openings of the scotch yokes. Therefore, the associated movement between the piston rod and the scotch yokes cannot be obtained. This means that the valve driving apparatus cannot fulfill its function to precisely open and shut the valve.
In orderto prevent the aforementioned adverse phenomenon from occurring, there has heretofore been adopted means comprising a pair of grooves formed on the inner surface of a case proper of the valve driving apparatus in parallel with the piston rod for allowing the extremeties of a pair of elongated pins to be inserted and held therein, whereby the rotating force of the piston rod is absorbed, or means comprising a pair of plane surfaces formed on the fixing portions between the piston rod and the pins and inserted between yoke portions pro vided on the driving shaft.
In the case of the spring-return type valve driving apparatus, the movement and force produced by the cylinder must cause the driving shaft to be rotated and the compression coil spring to be compressed.
Therefore, the force for rotating the valve stem is reduced by the force for compressing the compress ion coil spring to an extent about one half of the force for rotating the valve stem required in the case of the double-acting cylinder type valve driving apparatus.
Under these circumstances, it has heretofore been necessary to prepare a plurality of valve driving apparatuses in advance and to select one of the prepared valve driving apparatuses in accordance with the driving force required by the valve to be driven.
The conventionally known valve driving apparatus of a double-acting cylinder type has disadvantages in that a continuous reciprocating movement of the piston of the cylinder and a continuous rotating movement of the driving shaft give wear to the bearing portions for the piston rod and for the driving shaft, with the result that the replacement of the bearing portions with new ones is required in a comparatively short period of time, and in that use of the apparatus for a long period of time reduces the driving efficiency due to rust gathered on the inner wall of the cylinder, high frictional resistance between the cylinder and the piston and, in the utilisation of the scotch yoke type movement conversion transmission mechanism, due to high frictional resistance between the pins and scotch yokes.
On the other hand, in the conventionally known valve driving apparatus of a spring-return type, continuous compression and extension of the com pression coil spring disposed inside the apparatus gives rise to a phenomenon of relative displace ments in the rotating direction between the both ends of the compression coil spring and the both ends-receiving portions and further gives rise to a twisting phenomenon of the compression coil spring which phenomena are unavoidable characteristic features the compression coil spring has by nature.
Assuming that one end of the compression coil spring and the one end-receiving portion are in a state wherein these cannot easily be slid on each other, the other end of the compression coil spring is given a rotating movement which is transmitted to a spring holder fixed to the piston rod. That is to say, the rotating movement of the spring holder is transmitted to the piston rod and further to the piston. This will cause some possibility of the movement conversion-transmission mechanism dis posed between the piston rod and the driving shaft being given an inconvenient movement or force, such as causing disengagement between the pins and the scotch yokes in the scotch yoke type movement conversion-transmission mechanism, disengagement between the toothed wheels in a combination rack and pinion type movement con version-transmission mechanism, etc.However, since such a movement conversion-transmission mechanism has, in fact, a construction such that no such inconvenient movement is made though such inconvenient force is exerted on the movement conversion-transmission mechanism, attention to the aforementioned unavoidable phenomena must be paid. That is to say, the conventionally known valve driving apparatus of a spring-return type has disadvantages in that there occur displacement and friction between the both ends of the compression coil spring and the both ends-receiving portions within the apparatus to thereby give rise to energy loss, damage and wear, in that the rotating action of the valve stem may possibly be obstructed and in that the apparatus cannot be used precisely and stably for a long period of time for these reasons.
In accordance with the present invention, a valve driving apparatus comprises a case proper provided in the interior thereof with a movement conversiontransmission mechanism; a cylinder mechanism freely detachably fixed to one end of said case proper and including a cylinder possessed of ports serving as inlet and outlet for a pressurised fluid, a piston disposed inside said cylinder and a piston rod fixed to said piston so as to produce a given output; a piston rod supporting mechanism freely detachably fixed to the other end of said case proper; said movement conversion-transmission mechanism serving to convert the reciprocating movement of said piston into a rotating movement and simultaneously transmit the rotating movement to a driving shaft connected to a valve stem; and bearing portions provided near the junctions of said cylinder mechanism and said case proper, and said case proper and said piston rod supporting mechanism, for supporting said piston rod and further provided on said driving shaft for supporting said driving shaft.
Advantages of the present invention are that the valve driving apparatus: is capable of easy modification for driving any kind of valve irrespective of the magnitude of the driving force required by the valve to be driven; has a simple construction capable of causing the valve to be opened and shut precisely and stably; is capable of solving the problem of wear of the bearing portions for the piston rod and for the driving shaft; is capable of having its driving efficiency enhanced by reducing frictional resistance in a scotch yoke type movement conversion-transmission mechanism; is capable of providing excellent durability and corrosion-proofness; and is capable of solving the problems of wear, energy loss and damage caused by displacement and friction of the ends of a compression coil spring in apparatus of the spring-return type.
Preferably, the valve driving apparatus is provided with cylindrical bearing members possessed of the same shape and diameter and located by said bearing portions for said piston rod and said bearing portions for said driving shaft, said-cylindrical bearing members for said piston rod and for said driving shaft being replaceable with each other due to the difference in weartherebetween; other cylindrical bearing members made of the same material as the aforementioned cylindrical bearing members and attached to both pins in the case of a scotch yoke type movement conversiontransmission mechanism so as to reduce the frictional resistance between the pins and the scotch yokes;; a lining member made of a synthetic resin and applied to the inner wall of the cylinder mechanism and a resilient member such as of synthetic rubber embedded in a groove formed on the circumference of the piston to thereby enhance the durability and corrosion-proofness of the apparatus; and at least one cylindrical thrust bearing member disposed on the portions for receiving the ends of a compression coil spring in the case of a springreturn type valve driving apparatus so as to reduce the frictional resistance between the-ends of the compression coil spring and the end-receiving portions within the apparatus.
Examples of valve driving apparatus according to the present invention will now be described with reference to the accompanying drawings in which: Figure lisa partially cutaway longitudinal cross section illustrating the principal portion of one existing valve driving apparatus.
Figure 2 is a partially cutaway longitudinal cross section of the principal portion of another existing valve driving apparatus.
Figure 3 is a partially cutaway longitudinal cross section ofthe principal portion of still another existing valve driving apparatus.
Figure 4 is a lateral cross section illustrating one embodiment of the valve driving apparatus according to the present invention.
Figure 5 is a lateral cross section illustrating another embodiment of the valve driving apparatus according to the present invention.
Figure 6 is a lateral cross section illustrating still another embodiment of the valve driving apparatus according to the present invention.
Figure 7 is a partially cutaway enlarged front view of the valve driving apparatus shown in Figure 4.
Figure 8 is a partially cutaway longitudinal cross section illustrating the principal portion of the valve driving apparatus shown in Figure 4, 5 or 6.
Figure 9 is a partially cutaway plan view of Figure 8.
Figure 10 is an enlarged cross section taken along the line Ill-Ill in Figure 4 or 6.
Figure 11 is a longitudinal cross-section illustrating a cylinder-operation type gate valve on which the valve driving apparatus of the present invention may be provided.
Figure 12 is a partially cutaway plan view illustrating a butterfly valve on which the valve driving apparatus of the present invention may be provided.
Figure 13 is a lateral cross section illustrating a further embodiment of the valve driving apparatus according to the present invention.
Figure 14 is a lateral cross section illustrating a still further embodiment of the valve driving appratus according to the present invention.
Figure 15 is a partially cutaway front view of Figure 14.
When a scotch yoke type movement conversion transmission mechanism is used and openings of the scotch yokes are disposed at right angles relative to the piston rod 1, the piston rod and pins 10 fixed on the piston rod are rotated in the direction of the width of the piston rod as illustrated in Figure 1 and, therefore, the parallel relation between the pins and the driving shaft 8 of the valve driving apparatus cannot be maintained, with the result that the pins are out of engagement with the openings of the scotch yokes. Therefore, the associated movement between the piston rod 1 and the scotch yokes cannot be obtained. This means that the valve driving apparatus cannot fulfill its function to pre cisely open and shut the valve.In order to prevent the aforementioned adverse phenomenon from occurring, there has heretofore been adopted means comprising a pair of grooves 4,4 formed on the inner surface of a case proper 3 of the valve driving apparatus in parallel with the piston rod 1 for allowing the extremities of a pair of elongated pins 2, 2 to be inserted and held therein, whereby the rotating force of the piston rod is absorbed (Figure 2), or means comprising a pair of plane surfaces 7,7 formed on the fixing portions between the piston rod 6 and the pins 5,5 and inserted between yoke portions 9 provided on the driving shaft 8, whereby the rotation of the piston rod is prevented (Figure 3).
Now, the present invention will be described hereinafter in full detail with reference to the accom panying drawings.
Figure 4 is a lateral cross section illustrating one embodiment of the valve driving apparatus accord ing to the present invention which apparatus is of a double-acting cylinder type utilising a pair of scotch yokes as a movement conversion-transmission mechanism. The valve driving apparatus comprises a case proper 26, a cylinder mechanism 34 freely detachably fixed to a flange portion 48 of the case proper with bolts 35 and a stopper member 38 as a piston rod supporting mechanism 33 freely detach ably fixed to a fitting portion 36 of the case proper with bolts 39.The cylinder mechanism 34 comprises a cylinder 11 having ports 12, 13 serving as inlet and outlet for a pressurised fluid, a piston 14 disposed inside the cylinder and a piston rod 15 fixed to the piston by means of a nut 16 so that it may be moved in the rightward and leftward directions in conjunc tion with the piston. The piston rod 15 is movably supported by bearing portions 27, 28. The piston 14 shown in Figure 4 is in a state wherein it has reached the rightward extremity of its moving range. When a pressurised fluid is introduced from the port 13 into the cylinder 11, the piston in such a state is moved in the leftward direction.Thereafter, when a pressu rised fluid is introduced from the port 12 into the cylinder 11, the piston is moved in the rightward direction, with the result that the fluid introduced from the port 13 into the cylinder is discharged out of the cylinder from the port 13 since it has lost its pressurised state by the action of a switch valve (not shown) connected to the ports 12, 13. The cylinder mechanism as constructed above is capable of producing a given output. The stopper member 38 as the piston rod supporting mechanism 33 is provided with a stopper 37.The case proper 26 is provided in the interior thereof with a movement conversion-transmission mechanism 30 for converting the reciprocating movement of the piston rod into a rotating movement to a driving shaft 21 mounted on a valve stem (not shown) of a valve to be driven.
Since the valve driving apparatus according to the present invention has such a construction that the case proper and the stopper member are freely detachably fixed to each other, there can be pro vided a spring-return type valve driving apparatus, as illustrated in another embodiment of Figure 5, merely by replacing the stopper member 38 with a spring box 43 as the piston rod supporting mechan ism 33 or, as occasion demands, a double-acting two-cylinder type valve driving apparatus (not shown) merely by substituting another cylinder mechanism capable of functioning in the same manner as the cylinder mechanism 34 for the stopper member 38.In the embodiment of Figure 5, the spring box 43 accommodates therein a com pression coil spring 24 and is freely detachably fixed to the fitting portion 36 of the case proper 26 with bolts 44 and is possessed of a spring holder 25 fixed to the piston rod and a box cover 45 on which a stopper 46 is provided.
In-comparison between the valve driving appar atuses shown in Figures 4 and 5, since the magnitudes of the outputs produced by the respective cylinders are the same and since the output pro duced by the cylinder of Figure 5 is absorbed by the compression coil spring 24, the valve-driving force of the apparatus of Figure 5 is reduced by the output absorbed by the compression coil spring. Therefore, the apparatus of Figure 5 cannot be used for the valve capable of being fully driven by the apparatus of Figure 4.However, since the valve driving appar atus has such a construction that the case proper 26 and the cylinder mechanism 34 are freely detachably fixed to each other, the valve fully driven by the apparatus of Figure 4 can be driven in the same manner by replacing the cylinder mechanism 34 with another cylinder mechanism 34' having a cylinder 40 shown in still another embodiment of Figure 6 which cylinder has a larger inner diameter than that of the cylinder 11 so as to produce a higher output than that of the cylinder 11 by the output absorbed by the compression coil spring 24.
The cylinder mechanism 34' of this embodiment comprises a cylinder 40 having ports 12, 13 for inlet and outlet for a pressurised fluid, a piston 41 disposed inside the cylinder and a piston rod 15 'fixed to the piston and is freely detachably fixed at the flange portion 47 thereof to the flange portion 48 of the case proper 26 with bolts 35 and, therefore, it produces a higher output than that of the cylinder mechanism 34 of the embodiment of Figure 5 and can function in the same manner as the cylinder mechanism 34.
As is clear from the above, the valve driving apparatus according to the present invention can be used as any type of apparatus such as an apparatus of a double-acting cylinder type, an apparatus of a spring-return type or an apparatus of a doubleacting two-cylindertype and can be utilised for any valve merely by suitably selectively using the mechanisms between which the case proper intervenes.
The movement conversion-transmission mechanism 30 shown in Figure 4, 5 or 6 comprises a pair of pins 17,17 provided on the piston rod 15; a pair of scotch yokes 18, 18 each having yoke portions 20,20 and an opening 19 enclosed buy a pair of opposed sliding surfaces 23, 23 and a thrusting surface 22; and a key 29. The pin 17 is engaged with the opening 19. The mechanism 30 causes the scotch yokes 18 to be swung relative to the driving shaft 21 connected to the valve stem (not shown) by causing the pins 17, 17 to be slid on the sliding surfaces 23 in conjunction with the reciprocating movement of the piston rod 15.When the openings 19, 19 of the scotch yokes are disposed at right angles relative to the piston rod, as shown in Figure 8 or 9, the peripheral surfaces of the pins 17, 17 are also brought into thrust contact with the thrusting surfaces 22, 22 formed in the axial direction of the driving shaft 21. When the openings are disposed aslant relative to the-piston rod 15, as shown in Figure 4, 5 or 6, the pins 17, 17 are just brought into sliding contact with the sliding surfaces 23. Since the width of the opening 19 is substantially the same as the diameter of the pin 17 to an extent capable of causing the pin to be slid on the sliding surfaces of the scotch yoke, the piston rod 15 is prevented from being rotated. The pins are thus maintained at a parallel relation to the driving shaft 21 at all times.Therefore, not only the drive of the pins 17 and the scotch yokes 18 but also the drive of the piston 14 and the spring holder 25 is precisely transmitted to the driving shaft 21 and, moreover, a valve can exactly be rotated by ninety degrees through the medium of the valve stem (not shown) connected with the driving shaft.
Since the pins provided on the piston rod are held in parallel with the driving shaft at all times, as described above, the valve can be rotated precisely and stably through the medium of the valve stem connected to the driving shaft and, at the same time, there is no danger that any part is damaged due to a considerably simpler construction than that of any existing valve driving apparatus. That is to say, the durability ofthe valve driving apparatus is conspicuously prolonged and the mass production of the valve driving apparatuses can be effected at low expenses.
Although the scotch yokes are used as the movement conversion-transmission mechanism in all the embodiments of the present invention, it goes without saying that there may selectively be adopted a link mechanism our a combination rack and pinion mechanism.
Since the bearing portions 27, 28 support the reciprocating movementBof the piston rod 15, whereas bearing portions 49,49 support the rotating movement of the driving shaft 21, the pressure exerted on the former bearing portions and that exerted on the latter bearing portions are different from each other and, therefore, repetitive reciprocating and rotating movements give wear to the bearing portions in different sections. In view of this fact, attention has been paid to use of cylindrical bearing members which are identical in material, shape and diameter. Into the bearing portions 27, 28 for the piston rod 15 and the bearing portions 49,49 for the driving shaft 21, cylindrical bearing members 50,51,52 and 53 made of a synthetic resin or a copper alloy and formed in the same shape and diameter are inserted respectively.
T'o be more specific, the-cylindrical bearing members protect the bearing portions from wear and at the same time can be replaced with each other since these are formed in the same material, shape and diameter in view of the difference in wear between the cylindrical bearing members which difference is made due to different movements between the piston rod and the driving shaft. After use of the apparatus for some period of time in a state wherein the cylindrical bearing members 50, 51 are used for the piston rod 15 and the cylindrical bearing members 52,53 are used for the driving shaft 21, the members 50, 51 can be used for the driving shaft 21 and the members 52,53 can be used for the piston rod 15 because of the aforementioned difference in wear therebetween.This replacement brings about substantially the same function and effect as in the case of replacement of these cylindrical bearing members with new ones. Use of these cylindrical bearing members, thus, makes the apparatus excellent in durability and economisation and enhances the driving efficiency of the apparatus since the apparatus attains its function smoothly and precisely for a long period of time.
Now, a valve driving apparatus using a scotch yoke type movement conversion-transmission mechanism has been considered. Since the openings 19 ofthe scotch yokes 18 and the pins 17 are engaged with each other, problems on wear and damage may possibly be raised. In consideration of these problems, cylindrical bearing members 54 made of a synthetic resin or a copper alloy are rotatably provided on the pins 17 through the medium of bearing portions 55.Use of the cylindrical bearing members can reduce the frictional resistance between the scotch yokes and the pins even at either the time the pins are sliding on the sliding surfaces 23 of the scotch yokes 18 or the time the pins are brought into thrust contact with the thrusting surfaces 22 when the openings 19 are disposed at right angles relative to the piston rod 15 and, therefore, can further enhance the driving efficiency of the apparatus.
Figure 11 is a longitudinal cross section of a cylinder-operation type gate valve. In the Figure, reference numeral 56 is a gate valve and denoted by 57 is a valve body of the gate valve. Figure 12 is a partially cutaway plan view of a butterfly valve 58, in which reference numeral 59 is a driving shaft connected with a valve stem of the butterfly valve, 60 a rotating member installed on the driving shaft 59 and 61 a supporting plate for pivotally supporting the apparatus proper.
Since a valve driving apparatus utilises the reciprocating movement of a piston, the piston is required to smoothly move within the apparatus. The present invention also provides a valve driving apparatus wherein the inner wall of the cylinder mechanism 34 is coated with a lining member 63 of low frictional resistance made such as of a synthetic resin and the piston 14 is provided on the peripheral surface thereof with an annular groove 64 filled with an annular resilient member 65 of low frictional resistance made such as of a synthetic rubber, synthetic resin, etc. so that the resilient member is slid on the lining member.The coat of the inner wall of the cylinder mechanism 34 with the lining member prevents rust from being gathered and, in conjunction with the resilient member, not only prevents damage and wear due to its own resilience but also reduces frictional resistance therebetween.
Therefore, the present invention provides a valve driving apparatus excellent in durability, corrosionproofness and driving efficiency.
Returning to Figures 5 and 6, the compression coil spring 24 is compressed and extended in the range of the length Lwhen the piston rod 15 reciprocates for the purpose of transmitting to the driving shaft 21 the rotating movement converted from the reciprocating movement. In the movement of the compression coil spring in the range of the length L relative displacements in the rotating movement are produced between the both ends of the compression coil spring 24 and the both ends-receiving portions 66,67 within the spring box 43 and then a twisting phenomenon of the compression coil spring occurs.
In view of such phenomena, the present invention provides a valve driving apparatus wherein one or two cylindrical thrust bearing members 68 such as a metallic plate coated with a tetrafluoroethylene resin, oil-containing sintered metallic plate, copper alloy plate, etc. are disposed between one end of the compression coil spring and the box cover 45 and/or between the other end of the compression coil spring and the spring holder 25. According to the present invention, therefore, the twisting phenome non, friction resulting from such phenomenon and wear due to such friction can fully be prevented, with the result that both the conversion of the reciprocat ing movement into the rotating movement within the valve driving apparatus and the open-shut operation of the valve can precisely be effected.
As described above, the present invention pro vides considerably useful valve driving apparatuses from a practical point of view and, therefore, contri butes greatly to this field.

Claims (11)

1. Avalve driving apparatus comprising a case proper provided in the interior thereof with a movement conversion-transmission mechanism; a cylinder mechanism freely detachably fixed to one end of said case proper and including a cylinder possessed of ports serving as inlet and outlet for a pressurised fluid, a piston disposed inside said cylinder and a piston rod fixed to said piston so as to produce a given output; a piston rod supporting mechanism freely detchably fixed to the other end of said case proper; said movement conversion transmission mechanism serving to convert the reciprocating movement of said piston into a rotat ing movement and simultaneously transmit the rotating movement to a driving shaft connected to a valve stem;-andbearing portions provided near the junctions of said cylinder mechanism and said case proper, and said case proper and said piston rod supporting mechanism, for supporting said piston rod and further provided on said-driving shaft for supporting said driving haft.
2. A valve driving apparatus according to Claim 1, wherein said movementconversion-transmission mechanism is of a scotch yoke type and comprises a pair of pins provided on said piston rod; a pair of scotch yokes each including a pair of opposed sliding surfaces and a thrust surface so as to form an opening for allowing a respective one of said pins to beengagedtherewith; and dne or more keys for fixing said pair of scotch yokes to said driving shaft;; said-pair of pins being brought into sliding contact with said sliding surfaces when said openings are disposed aslant relative to said piston rod and, when said openings are disposed at right angles relative to - said piston rod, being brought into thrust contact with said thrust surfaces while maintaining the contact with said sliding surfaces, so as to constantly maintain parallel relation between said driving shaft and said pair of pins, whereby the valve is precisely and stably driven.
3. A valve driving apparatus according to Claim 2, further comprising a pair of cylindrical bearing members attached to the peripheral surfaces of said pair of pins and rotatably supported by respective bearing portions.
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4. A valve driving apparatus according to any preceding claim, further comprising cylindrical bear ing members possessed of the same shape and diameter and located by said bearing portions for said piston rod and said bearing portions for said driving shaft, said cylindrical bearing members for said piston rod and for said driving shaft being replaceable with each other due to the difference in wear therebetween.
5. A valve driving apparatus according to any preceding claim, wherein said cylinder mechanism has an inner wall thereof coated with a lining member of a synthetic resin, and said piston is provided on the periphery thereof with a groove and in said groove with a resilient member so that said resilient member is slid on said lining member.
6. A valve driving apparatus according to any preceding claim, wherein said piston rod supporting mechanism is a stopper member having a stopper; or a spring box comprising a compression coil spring accommodated therein, a box cover, a stop per provided on said box cover and a spring holder; or a cylinder mechanism of the same type as said cylinder mechanism so as to constitute any one of the valve driving apparatuses of a double-acting cylinder type, a spring-return type and a double acting two-cylinder type.
7. A valve driving apparatus according to Claim 6, further comprising a cylindrical thrust bearing member which is a metal plate coated with a tetrafluoroethylene resin, an oil-containing sintered metal plate or a copper alloy plate, and which is provided either between one end of said compress ion coil spring and said box cover, or between the other end of said compression coil spring and said spring holder, or is provided both between one end of said compression coil spring and said box cover and between the other end of said compression coil spring and said spring holder.
8. A valve driving apparatus according to Claim 1 and substantially as hereinbefore described with reference primarily to any one of Figures 4,5,6,13 or 14, of the accompanying drawings.
9. A valve driving apparatus comprising a case proper provided in the interior thereof with a movement transmission, or conversiontransmission, mechanism; a cylinder mechanism freely detachably fixed to one end of said case proper and including a cylinder possessed of ports serving as inlet and outlet for a pressurised fluid, a piston disposed inside said cylinder and a piston rod fixed to said piston so as to produce a given output; a piston rod supporting mechanism freely detachably fixed to the other end of said case proper.
10. Avalve driving apparatus according to Claim 9, wherein said cylinder mechanism has an inner wall thereof coated with a lining member of a synthetic resin, and said piston is provided on the periphery thereof with a groove and in said groove with a resilient member so that said resilient member is slid on said lining member.
11. A valve driving apparatus according to Claim 9 or Claim 10, wherein a movement conversiontransmission mechanism is provided, which serves to convert the reciprocating movement of said piston into a rotating movement and simljitaneously transmit the rotating movement to a driving shaft connected to a valve stem.
GB8018235A 1979-06-08 1980-06-04 Valve driving fluid operated actuator Expired GB2056565B (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP1979078108U JPS6214461Y2 (en) 1979-06-08 1979-06-08
JP7811179U JPS55177572U (en) 1979-06-08 1979-06-08
JP1979078109U JPS6141011Y2 (en) 1979-06-08 1979-06-08
JP1979078107U JPS594217Y2 (en) 1979-06-08 1979-06-08 valve drive device
JP7811079U JPS55177504U (en) 1979-06-08 1979-06-08

Publications (2)

Publication Number Publication Date
GB2056565A true GB2056565A (en) 1981-03-18
GB2056565B GB2056565B (en) 1983-11-02

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB8018235A Expired GB2056565B (en) 1979-06-08 1980-06-04 Valve driving fluid operated actuator

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Country Link
GB (1) GB2056565B (en)
IT (1) IT1131525B (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0203426A1 (en) * 1985-05-07 1986-12-03 Norsk Hydro A/S Actuator for transmission of a rectilinear motion to a rotating motion
GB2182721A (en) * 1985-11-09 1987-05-20 Hytork Actuators Ltd Improvements in or relating to fluid-pressure-operated actuators
US4702150A (en) * 1985-06-21 1987-10-27 Kitz Corporation Spring-return type actuator
WO2001042695A1 (en) * 1999-12-08 2001-06-14 Ring-O-Valve Norge As A ball valve device
CN101858459A (en) * 2010-06-22 2010-10-13 季忠庸 Ready-package pneumatic actuator
CN101881352A (en) * 2010-06-22 2010-11-10 季忠庸 Pneumatic actuator
CN107250565A (en) * 2014-12-01 2017-10-13 罗托克流体系统有限责任公司 Valve actuator equipment with the actuating arm with modular construction

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0203426A1 (en) * 1985-05-07 1986-12-03 Norsk Hydro A/S Actuator for transmission of a rectilinear motion to a rotating motion
US4702150A (en) * 1985-06-21 1987-10-27 Kitz Corporation Spring-return type actuator
AU572720B2 (en) * 1985-06-21 1988-05-12 Kitz Corp. Spring return rotary valve actuator
GB2182721A (en) * 1985-11-09 1987-05-20 Hytork Actuators Ltd Improvements in or relating to fluid-pressure-operated actuators
WO2001042695A1 (en) * 1999-12-08 2001-06-14 Ring-O-Valve Norge As A ball valve device
CN101858459A (en) * 2010-06-22 2010-10-13 季忠庸 Ready-package pneumatic actuator
CN101881352A (en) * 2010-06-22 2010-11-10 季忠庸 Pneumatic actuator
CN107250565A (en) * 2014-12-01 2017-10-13 罗托克流体系统有限责任公司 Valve actuator equipment with the actuating arm with modular construction

Also Published As

Publication number Publication date
IT8022642A0 (en) 1980-06-06
IT1131525B (en) 1986-06-25
GB2056565B (en) 1983-11-02

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