JPS60188677A - Bellow type sealed rotary valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve, and more particularly to a valve having a bent valve stem sealed with a bellows which is bent and internally pressurized, within which the end portions of the valve stem are displaced in a parallel relationship and Rotation is transmitted from the actuator to the valve stem through the pressure boundary formed by the bellows, which are rotatably connected to an actuator having an axis aligned with the lower axis of the valve stem and offset from the upper axis. This invention relates to a rotary valve supported along its length by a valve stem to resist lateral bending.

In contrast to pack or dynamic seals, rotary valves such as bare, globe, and plug types for transferring fluids, especially contaminated fluids, at high pressures, as well as under significantly reduced pressure or vacuum conditions, are It is preferred to use stickers for

Puck or dynamic seals are subject to wear, which can result in valve leakage, particularly at the pressure interface between the valve stem and the valve member. A commonly used locking seal is a bellows that surrounds the valve stem.

U.S. Pat. Nos. 1,644,825, 2,659,569, 2,659,570 and 3,811,651 disclose valves that utilize a sealing bellows around the valve stem between the valve actuator and the valve member.

Traditionally, when a bellow is used to seal a valve stem, one end is glued or welded to the structure of the valve body that supports the rotating member, and the other end is bonded or welded to a retainer or cap that connects the valve stem to the valve actuator. be done.

This arrangement is shown in US Pat. No. 3,811,651. The connections at both ends of the bellows are fixed, thus creating a fixed seal. It is well known to laterally bend the valve stem or utilize a cranked valve stem to seal the valve body within the bellows. Thus, the valve body connects the actuating device to the valve member to rotate the valve as disclosed in US Pat.
No. 644825 and No. 3811651.

One of the difficulties with curved valve stems that are sealed within bellows and actuated by crank-like actuators is constraining the rotating end of the valve stem located in a retainer or cap within the valve actuator. Particularly in high pressure applications, the pipe pressure exerts an upward force on the valve stem and bellows cap as well as tends to displace the valve stem and bellows cap laterally. If the upper end of the valve stem and/or bellows cap is displaced laterally relative to the axis of rotation of the actuator, friction will occur between the valve stem, bellows cap, and retainer, resulting in prevent rotation.

As a result, rotation of the actuator will not rotate the valve stem and rotation will be inhibited to the extent that the valve will not reliably open or close.

Another problem with internally pressurized bellow-sealed valve stems is that the bellows bend outward, placing stress on the bellows. Also, when subjected to axial compression, the bellows
It is prone to sideways bending, known as sagging, which also stresses the bellows and causes them to break.

Although the use of bellows to seal the valve stem has been proposed in prior art devices, the use of bellows is not too common, as it can be used as a fixed seal or as an axially movable seal, and the bellows are subject to torsional loads. It cannot be used as a rotary seal in case. Accordingly, the bellows are supported to resist bending to the valve stem and are connected to the actuating device in such a way as to maintain a pressure boundary around the valve stem while transmitting torque to the valve stem through the bellows. The need for a rotary seal on the valve stem is found in rotary valves.

According to the present invention, a valve is provided that includes a valve body and a flow path passing through the valve body for flowing fluid. A valve member is disposed in the flow path for movement between open and closed positions to open and close the flow path. The valve member has a shaft. An actuator rotatable about an axis coaxially aligned with the axis of the valve member moves the valve member between an open position and a closed position.

A single valve stem extends between the valve member and the actuator. The single valve stem has a lower end portion non-rotationally engaged with the valve member and an upper end portion coupled to the actuator for transmitting rotation from the actuator to the valve member. The upper end portion of the valve stem is displaced from the lower end portion of the valve stem. The lower end portion of the valve stem has a lower axis aligned with the valve stem axis and the actuator axis. The valve stem pivots its upper end portion about the valve member as the actuator rotates to place the valve member in an open position or in a closed position. A bearing structure carried by the actuator supports the upper end portion of a single valve stem for rotation relative to the actuator. A bearing structure supports the upper end portion of a single valve stem and maintains the upper end portion of the valve stem rotatable relative to the actuator in response to external forces being applied to the valve stem. The bellows surround the single valve stem. The bellows has a lower end portion and an upper end portion. Apparatus is provided for connecting the lower end portion of the bellows to the valve body to form a seal around the lower end portion of the valve stem at the valve body. The upper end portion of the bellows is coupled to a bearing structure to provide relative movement between the upper end portion of the bellows and the actuator to form a seal around the upper end portion of the valve stem.

The housing rotatably supports the actuating device and is connected to the valve body. A housing surrounds the bellows and is connected to the valve body in sealed relation surrounding the actuator to define a chamber about the bellows.

This chamber forms a secondary pressure boundary to support the primary pressure boundary formed by the bellows around the valve stem, so if the bellows fails, fluid and line pressure will be contained within the chamber formed by the housing. It will be done.

Further, in accordance with the present invention, there is provided a valve including a valve body and a flow path passing through the valve body for allowing fluid to flow therethrough. A valve member is disposed in the flow path for moving between an open position and a closed position to open and close the flow path. An actuator rotatable about the axis moves the valve member between an open position and a closed position. A valve stem extends between the valve member and the actuator. The valve stem has a lower end portion connected to the valve member and an upper end portion connected to the actuator for transmitting rotation of the actuator to the valve member. The upper end portion of the valve stem is offset from the lower end portion of the valve stem, giving the valve stem a curved shape. The valve surrounds the valve stem to form a seal around the valve stem between the valve body and the actuator.

The bellows has a curved shape that corresponds to the curved shape of the valve stem. The valve stem has an outer surface, and the bellows has an inner surface that is placed very close to the outer surface of the valve stem, so that when the bellow is subjected to pressure, the valve stem supports the bellow so that it does not warp sideways. prevent.

The bellows first bend around the valve stem. There is a small clearance between the valve stem and the bellows, so that the bellows is supported by the valve stem virtually along its curved length. The valve stem thus has an unlimited deflection or "warmth" of the bellows.
, and the bellows can handle higher pressures.

By increasing the surface area between the bellows and the valve stem, local distortion or twisting of the bellows at the focal point is eliminated.

Therefore, the main object of the present invention is to connect the valve stem to the valve actuating device by a bearing structure to transmit torsion and rotational motion from the actuating device to the valve stem through the bearing structure and bellows, and to resist lateral vibration. The object of the present invention is to provide a rotary valve having a bent valve stem surrounded by a bent bellows supported on the stem.

Another object of the invention is a rotary valve in which a valve stem is sealed within a bellows and rotatably supported by an actuator by a bearing structure that provides relative rotational movement between the valve stem and the actuator. The object of the present invention is to provide a valve actuating device having an axis of rotation offset from and parallel to the axis of rotation of the rod.

Another object of the invention is to provide a rotary valve having a bent valve stem sealed by an internally pressurized bellows supported by the stem.

These and other objects of the invention are more fully disclosed in the following specification, accompanying drawings, and appended claims.

Some embodiments of the present invention will be described by way of example with reference to the accompanying drawings.

Referring to the drawings, and in particular to FIGS. 1 and 2, there is shown a valve structure, generally designated 10, of the globe valve type for controlling the flow of fluid, i.e., liquid or gas, through a piping system. . The valve structure 10 is attached to the central valve body portion 20 with bolts 18.
It includes a valve body, generally designated 12, having a pair of conduit portions 14 and 16 connected to the valve body. Conduit sections 14 and 1
6 is received in the recess 22 of the central valve body portion 20. Valve seat 24 is disposed within recess 22 and abuts adjacent ends of conduits 14 and 16. Valve seat 24 is secured within recess 22 by central valve body portion 20 and conduits 14 and 16 to define a valve chamber, generally designated 26.

Valve chamber 26 communicates with conduits 28 and 30 passing through conduit sections 14 and 16, respectively. Conduits 28 and 3
0 is aligned with conduit 32 passing through valve seat 24. Conduit sections 14 and 16 are configured to connect to a service tube by any suitable means, such as by screwing the service tube into the conduit end sections 14 and 16. In this way, a continuous flow path is provided through the valve structure IO.

A rotatably articulated valve member 34 is connected to a valve stem 36 which is rotated by a valve actuator, generally designated 38. Although the valve assembly 34 shown in FIG. 1 is typical of valve members utilized in globe valves, the present invention is suitable for other suitable rotary valve members, such as screw valves, plug valves, etc. Please understand that you can also use it. Valve member 34 includes a disc portion 40 having an arcuate surface 42 . The arcuate surface 42 is the valve body portion 40
remains in contact with the valve seat 24 as it rotates within the valve chamber 26. Valve body portion 40 has a through hole 44 that is aligned and misaligned with conduits 28 and 3o of conduits 14 and 16 and conduit 32 of valve seat 24 to center fluid between conduit portions 14 and 16. It is made to pass through the inside of the valve body portion 20. When the valve stem 36 is rotated 90 degrees, the valve member 34 is placed in the open position or in the closed position.

The open and closed positions of the valve member 34 as shown in FIG.
(not shown) is controlled by orbital movement of the valve actuator 38 about an axis 46 that is coaxially aligned with the lower end portion 48 of the valve stem 36. The lower end portion 48 of the valve stem is non-rotatably connected to the valve member 34. The lower end portion 48 and the valve member 34 are rotatable about an axis 50.

As shown in FIG. 1, shaft 50 is coaxially aligned with actuator shaft 46. The valve stem 36 is also a valve actuator 38
including an upper end portion 52 connected to the upper end portion 52 . Upper end portion 52 of the valve stem
has a paternal axis 54 laterally from both axes 46 and 50. Additionally, as shown in FIG. 1, axis 54 is parallel to axes 46 and 50. In this device, the shaft 54 is the shaft 4
6 and 50 eccentric. Valve stem upper end portion 52 is connected to actuator 38 so that torque is transmitted from actuator 38 to valve stem 36 and valve member 34 .

Valve stem 36 is a unitary member between end portions 48 and 52 and has a preselected curvature that is a double curvature or a counter-curvature. The valve stem upper end portion 52 is rotatably connected to the actuator 38 by a bearing structure generally designated 56. A bellows 58 surrounds the valve stem 36 between its upper end portion 52 and lower end portion 48. The bellows 58 has a generally cylindrical body portion 60 having a single length, circumferentially corrugated, and axially extending relatively thin cylindrical wall. Under normal conditions,
The bellows are not bent, and after a few strokes, they bend into the shape of a valve stem.

Preferably, bellows 58 is metallic, impermeable, and flexible enough to withstand bending that occurs during bellows operation. Bellows 58 has a passageway 62 extending between a lower open end portion 64 and an upper open end portion 66. Preferably, bellows 58 has an inner diameter located in close proximity to the outer diameter of valve stem 36. −
In the example, the inner diameter of the bellows is spaced from the outer diameter of the valve stem by a distance equal to 10% of the stem diameter. With this arrangement, valve 1436 contacts and supports bellows 58 when bellows 58 receives internal and external fluid pressure, thereby preventing lateral strain or "sagging" of bellows 58. do.

As a result of the countercurvature of valve stem 36, bellows 58 will contact valve stem 36 and conform to the curvature of bellows 58.

The bellows upper end portion 66 is coupled to the actuator 38 to permit relative rotation between the actuator 38 and the bellows upper end portion 66 such that torque is transmitted from the actuator 38 through the bellows 58 to the valve stem 36. . The bellows upper end portion 66 is axially aligned with the valve stem upper end portion 52 .
Part of the primary pressure boundary around 2. The lower end portion 64 of the bellows is axially aligned on the shaft 50 with the lower end portion 48 of the valve stem.

Bellows upper end portion 66 is coupled to actuator 38 to form a primary pressure boundary around valve stem upper end portion 42 in a manner to be described in detail below.

The bellows lower end portion 66 is connected to the bellows plate 68 by welds 67 to form a fireball boundary around the valve stem lower end portion 48 . The bellows plate 68 is suitably sealingly coupled to the central disc portion 20 of the valve to form a seal around the disc lower end portion 48 at the location where the valve stem 36 extends from the central disc portion 20.

The bellows plate 68 includes a through hole 69 through which the valve body 36 passes. The through hole 69 is the valve center valve body portion 2 that receives the lower end portion 48 of the valve stem.
It is aligned with the through hole 71 passing through 0. A suitable journal bearing 70 or bushing is located within the center valve body portion 20 and bellows plate 68. The bearing 70 is attached to the valve center valve body portion 20 and the bellows plate 68 within the valve stem lower end portion 4.
8 is rotatably supported.

Bellows plate 68 is suitably connected to central valve body portion 20 of the valve. As shown in FIG. 1, the bellows plate 68 is connected to the central valve body portion 20 of the valve by bolts 72. 3 and 4 show an alternative embodiment in which a bellows plate 68 is connected to the central valve body portion 20. FIG. 3 and 4, the bellows plate 68 is connected about its circumference to the upper surface of the central valve body portion 20 at 74 by a lateral weld. This arrangement forms a weld seal at the lower end portion 48 of the valve body for rotating the valve member 34 through 90 degrees.

The fixing O-ring seal 76 shown in FIG.
and the central valve body portion 20 of the valve to form a seal therebetween as well as around the lower end portion 48 of the valve stem.

In another embodiment shown in FIG. ilA, a dynamic O-ring seal 77 is disposed on the valve center disc portion 20 and is positioned to seal around and seal the lower stem portion 48. The O-ring seal 77 has an inverted U-shape, and because of this shape, the seal expands outwardly and engages the lower end portion 48 of the valve stem if there is a fluid leak between the valve seat 24 and the valve member 34. Enhances sealing engagement. This one-way seal prevents fluid from flowing up around the valve stem 36 but allows pressure to escape from the bellows 58 into the recess 22. Seal 77 may serve to reduce the pressure within the bellows to provide a safety margin for the cycle life of the bellows. Seal 77
It also enhances the cycle life of the bellows by reducing exposure of the bellows/stem to potentially abrasive or harmful fluids within the valve. The unidirectional nature of seal 77 prevents high pressure from becoming trapped within the bellows if the pressure within the valve decreases.

As shown in FIG. 1, actuator 38 includes a crank arm 78 that rotates about axis 46. As shown in FIG. The crank arm 78 is rotatably supported within an actuating housing 80 connected by bolts 82 to the surface of the central valve body part 0 of the valve in surrounding relation to the bellows plate 68. Housing 80 defines a chamber 84 surrounding valve stem 36 and bellows 58 and serves as a secondary pressure boundary around valve stem 36 to support the primary pressure boundary formed around valve stem 36 by bellows 58. do. With this arrangement, if leakage occurs around the valve stem 36 or through the bellows 58, the housing 80 will contain the leakage and line pressure within the chamber 84.

A locking seal is formed by an O-ring 86 between the flanged lower end portion of the housing 80 and the upper surface of the central valve body portion 20 of the valve. Additionally, a dynamic seal is provided around the crank arm 78 with an O-ring 88 retained within a recess in the tapered upper end portion of the housing 80.

O-ring 88 engages the outer surface of crank arm 78 in a sealing relationship.

Rotation is imparted to the crank arm 78 by an /X handle 90 non-rotationally connected to the crank arm 78 by a nut and bolt combination 92.

Therefore, when the handle 90 is rotated by a predetermined rotation angle,
The crank arm 78 rotates about the axis of rotation 46 to cause the upper end portion 52 of the valve stem to rotate in an orbit about the axis 46 so that the lower end portion 48 of the valve rotates about the axis 50 and then the valve member. 34 rotates to an open position or a closed position. Crank arm 78 includes an enlarged lower end portion 94 that is offset from axis 46 . The lower end portion 94 carries axial and radial thrust loads and is rotatably supported within the housing 80 by a bush-shaped thrust bearing 96 operable to rotatably support the enlarged end 94 of the crank arm. Thrust bearing 96
is also operable to resist axial movement of the enlarged lower end portion as pressure within bellows 58 increases. The enlarged end portion 94 includes a recessed portion 98 in which the axis of the recessed portion 98 coincides with the axis 5 of the upper end portion 52 of the valve stem.
It is aligned with 4. The recess 98 is offset from the axis of rotation 46 of the crank arm 78 so that the axis of the recess 98 is aligned with the axis 54 and is eccentric to the axis 46 of the actuator.

Bearing structure 56 is located within recess 98 .

Bearing structure 56 includes handle bearing portion 100
, the bearing portion being preferably a bushing type journal bearing operable to support both radial and thrust loads. The handle bearing 100 is retained within the recess 98 and in turn receives a cup-shaped bellows cup 102 . A handle bearing 100 supports a bellows cap 102 for rotation relative to the crank arm 7B. Bellow cap 102
then receives the valve stem bearing 104, which bearing 104 preferably operates to support radial loads.
This is a bush-type journal bearing with high performance.

A valve stem bearing 104 is disposed in surrounding relation to the valve stem top portion 52 to permit rotation of the bellows cap 102 relative to the valve stem top portion 52 . A valve stem bearing 104 is disposed on the valve stem shoulder 103;
A bearing 104 is positioned on the upper end portion 52 of the valve stem such that the bellows cap 1.02 axially moves in response to an upward axial force applied to the valve stem 36.

Bellows cap 102 is closed at one end to sealingly surround valve stem upper end portion 52 within recessed end portion 94 of crank arm 78 .

Bellows cap 102 includes a flanged open end portion disposed opposite bellows upper end portion 66 . The upper end portion 66 of the bellows is welded at 106 to the flange end of the bellows cap 102. This arrangement allows for relative rotation between the crank arm 78 and the bellows cap 102 welded to the upper end portion 66 of the bellows. Furthermore, relative rotation between the bellows cap 102 and the valve stem upper end portion 52 is possible. The combination of thrust and radial bearings 100 and 104 transmits torque from crank arm 78 to valve stem 36 as valve stem upper end portion 52 rotates about fixed rotational vertical axis 46 of crank arm 78.

The valve stem upper end portion 52 is hermetically sealed within the housing 80 by welding the bellows upper end portion 66 to the flanged end of the bellows cap 102 around the valve stem upper end portion 52. The welded connection 106 between the bellows 58 and the bellows cap 102 forms the primary pressure boundary of the valve to prevent escape of tubing fluid and pressure around the valve stem 36.

A secondary pressure boundary is formed by an O-ring 88 sealingly disposed between housing 80 and crank arm 78. Thus, the crank arm 78 and housing not only act as a device for actuating the valve 10, but also operate in combination with the O-ring 88 as a dynamic seal to support the primary pressure boundary formed by the bent bellows 58.

If the bellows fail or if there is a leak beyond the fireball force boundary, chamber 80 transfers fluid pressure and total line pressure to chamber 84.
It works to contain it inside. This arrangement confines high pressure and hazardous or contaminated fluids within the valve structure 10 and prevents them from escaping to the outside environment if the fireball interface fails. One advantage of the parallel stagger between axes 46 and 54 is a small clearance around axle 46 to crank arm 78. Through this gap, the inner diameter of 7-Using 80, therefore,
The dimensions of chamber 84 can be significantly reduced while still serving as a complementary pressure boundary. /1 Even if the wall thickness of the housing 80 is reduced by reducing the inner diameter of the housing 80, the internal pressure resistance capability of the /'% housing 80 is not reduced. This provides a secondary pressure boundary that is significantly lighter and less expensive than without the reduced wall thickness.

The housing 80 has the rotation axis of the crank arm 78 as the axis 46.
and axis 46 is also aligned with axis 50.

The rotation of the crank arm 78 about the axis of rotation 46 is maintained by the lower end portion 108 of the flange 4 = J of the housing 80 being located in the recessed portion 110 of the valve center valve body portion 20 . The flange end portion 108 is guided into position on the valve center valve body portion 20 by engagement with the recessed portion 110 . Surface 112 of housing end portion 108
is in contact with the wall of the concave portion 110. In this way,
Housing 80 is precisely positioned over center valve body portion 20 so that the axis of rotation of crank arm 78 is maintained in alignment with axes 46 and 50. Bellows plate 68 is similarly aligned with axes 46 and 50 by radial abutment with bearing 70. Bearing 70 is aligned in a radially abutting relationship with through hole 71 which is coaxially aligned with axes 46 and 50.

To actuate the valve structure 10 and place the valve member 34 in the open or closed position within the valve chamber 26, torque is applied to the handle 90 to move the crank arm 78 toward the shaft 4.
6, the enlarged lower end portion 94 and the valve stem upper end portion 52 now pivot about the axis 46. This causes the valve stem lower end portion 48 to begin to rotate about the axis 50 and the valve member 34 to begin to rotate about the axis 50. Bellow cap 1
02 also pivots about the axis 46 together with the lower end portion 52 of the valve stem. Crank arm j8 rotation handle bearing 100, bellow cap 102 and valve stem bearing 1
04 to the valve stem upper end portion 52. Therefore,
The rotation is transmitted by a force applied eccentrically to the upper end portion 52 of the valve stem. Valve actuation force is transmitted by torque applied to valve member 34 through bent bellows 58 outside the primary and secondary pressure boundaries.

Bellows cap 102 pivots about axis 46 but not about axis 54. The primary pressure boundary element, including bellows 58 and bellows cap 102,
It is fixed so that it does not rotate. However, bellows 58 bends to allow bellows cap 102 to pivot through two arcs about axis 46. End portion 94 and valve stem top portion 52 rotate about axes 46 and 50. Bearing gears 00 and 104 support bellows cap 102 for rotation relative to end portion 94 and valve stem top portion 52.

Further, in accordance with the present invention, thrust bearing 96, handle bearing 100, and valve stem bearing 104 have sufficient length and structural strength to prevent restriction of the rotational connection of valve stem top portion 52 to actuator 38. We are prepared. Therefore, the various connecting parts between them will not deviate laterally from the staggered and parallel alignment as described above. This maintains the actuator axis 46 in a spaced parallel relationship to the valve stem upper end axis 54.

In operation of the valve structure io having a pressure within the recess 22 that is greater than the pressure outside the housing 80, the bellows 58
is internally pressurized so that an upward thrust is imparted to the bearing structure 36 within the bellows. However, it is understood that the invention can also operate under low pressure and vacuum conditions. The combination of bearings 96, 100 and 104 resists the radial and thrust forces applied from the pressure within bellows 58 to maintain relative rotation between crank arm 78 and valve stem upper end portion 52. This arrangement of maintaining axes 46 and 54 parallel also allows axial movement of valve stem upper end portion 52 during operation of valve 10. Also, since this arrangement does not exert a biasing force on the bellows 58, there is no "rebound" effect on the bellows 58.

By maintaining axes of rotation 46 and 54 in a parallel relationship, a relatively conventional rotary actuation device, such as a handle 90 connected to crank arm 78, is utilized with the present invention. Torque applied to handle 90 is transmitted by crank arm 78 to staggered crank arm end portion 94, thereby transmitting a force to valve stem upper end portion 52 that deviates from the rotational force transmitted to crank arm 78.

Furthermore, by providing both the valve stem 36 and the bellows 58 with a double or countercurvature as shown in FIG. .

By maintaining these connections at right angles or in isolated parallel relationship, axial movement between valve stem 36 and valve actuator 38 is taken up by bearing structure 56. The bearing structure 56 maintains the displacement that occurs in the axial direction.

Therefore, any lateral forces acting on the valve stem upper end portion 52 are eliminated. This lateral force would otherwise tend to bind or otherwise fail the connection of the valve stem upper end portion 52 to the crank arm 78 during rotation. Not only that, but the fabrication of said surfaces is less costly since only conventional parallel and perpendicular surfaces are required.

In operation, the tongue 58 is internally pressurized by the pressure within the recess 22. As a result, an accordion-like expansion action is performed on the bellows, causing the bellows 58 to expand in the axial direction. However, when both end portions of the bellows 58 are fixed in the axial direction, the axial force acting on the bellows 58 is transmitted from the bellow upper end portion 66 to the bellows cap 102. Bellows cap 102 is biased upwardly in a direction parallel to axis 46. This upward axial force applied to bellows cap 102 is taken up by a combination of radial and thrust bearings 96° 100 and 104 which provide limited axial displacement of the connecting parts. Thus, by maintaining the rotation axes 46 and 54 in an isolated parallel relationship, any axial forces applied to the valve stem 36 and bellows 58 are taken up by the bearing structure 56. Pressure is maintained axially. The valve stem upper end portion 52 remains rotatable relative to the crankshaft 78.

Forces acting in the radial direction are limited to prevent binding of relatively rotating parts.

The internal pressurization of bellows 58 applies an upward lateral force to the bellows, causing the inner surface of bellows 58 to frictionally engage the outer surface of valve stem 36 . The valve stem 36 rotates within the bellows 58 and contacts the inner surface of the bellows 58 so that the bellows 58 conforms to the shape of the valve stem 36. A bent bellow is naturally unstable and therefore prone to distortion. The instability of the bellows 58 is further compounded by the fact that the interior of the bellows is pressurized. The overall effect of bending the bellows and applying internal pressure to the bellows is to increase the frictional contact of the bellows with the valve stem.

This results in bellows wear, which reduces the cycle life of the bellows and the valve stem's ability to maintain a primary pressure boundary around the valve stem 36.

As pressure is applied to the inside of the bellows 58, the bellows tend to buckle or "wiggle" sideways. A drawback of any bellows, especially elongated, flexible bellows, is that the maximum internal pressure that the bellows can support is limited. This is not based on the bellow wall strength or bursting pressure, but rather on the writhing pressure, which is lower than the bellows bursting pressure. This is the pressure that bends when subjected to a compressive load.This action can be compared to the bending of a long thin rod when subjected to a compressive load.

To enhance the stability of the initially bent bellows 58, a small gap is provided between the valve stem 36 and the bellows 58 such that the bellows 58 is supported by the valve stem 36 along substantially its bent length. is provided. In this manner, the valve stem 36 limits the unrestricted bending or "swivel" of the bellows 58. The clearance between the outer surface of the valve stem 36 and the inner surface of the bellows 58 extends substantially the entire length of the bellows. Preferably, the distribution is in surface contact with the rod.

By providing the bellows 58 with maximum stage NPr curvature in accordance with the valve stem 36 as shown in FIG. 7, the amount of spiral bending in each bellows is minimized.

At the bend in bellows 58, each spiral is tilted or curved toward axis 46 or axis 54.

As the bellows pivot about axis 54, each spiral has the same amount of bend, but the orientation of the bend is rotated to correspond to the rotation of axis 54. The repeated bending of each thin winding creates fatigue that can lead to breakage of the bellows. In addition to this, the internal pressure also affects the cycle life of the bend. However, in the case of the arrangement shown in FIG.
8 has a uniform curvature having a radius R at each bent portion, as schematically shown in FIG. Each bend has the same radius of curvature R.

Preferably, these two curved portions are continuous so that the countercurvature does not have an intermediate straight portion.

For this arrangement, the maximum radius of curvature of the bellows is used to obtain a preselected stagger of axes 50 and 54. Therefore, by maximizing the radius of curvature R of the bellows, the cycle life of the bellows 58 is increased by minimizing the spiral bending of each bellows. The bellows can withstand higher pressures and increased torque can be applied to the valve actuator 38 in the valve structure 10 having a compact shape.

By increasing the contact area between valve stem 36 and bellows 58, the overall stability of bellows 58 is increased and localized distortion or bending of the bellows at focal points is eliminated.

In the present invention, the multiple convolutions of bellows 58 contact valve stem 36 to minimize bending of bellows 98 when internal pressure is applied to it. Since the bellows and valve stem undergo relative rotational frictional movement, it is desirable to minimize wear and friction between the two parts.

Wear of the bellows is undesirable primarily because the bellows are relatively thin and the wall thickness decreases to the point where even slight wear can lead to failure of the bellows. Bellows wear is also accelerated by the friction created between the valve stem and bellows when torque is applied to the valve stem.

Valve stick: Connection with U6 #iJ! In order to prevent the bellows 58 from being worn out by the valve stem 36, the valve stem 36 is provided with a low friction outer surface or stem coating. FIGS. 8-10 illustrate various embodiments of the bent valve stem of the present invention having a low-friction outer surface supporting a minimized wear bellows.

When actuating valve structure 10 to rotate valve member 34 , bellows 58 bends around valve stem 36 as valve stem 36 rotates within bellows 58 . The bellows 58 does not rotate, but the valve stem 3
6 rotates against the bellows 58 relative to I7. Valve stem” second end part 5
2 and the bellows upper end portion 66 pivot about the axis 46.

During this orbital movement, the upper end portion 52 of the valve stem moves toward the upper end portion 20 of the valve stem.
However, the bellows upper end portion 66 does not rotate during the orbital movement. Later on, it occurs between valve $36 and bellows 58. The friction generated between the valve stem 36 and bellows 58 can also be reduced using a wear-resistant coating or shaft plating. For example, as shown in FIG. 8, a wear-resistant material, such as a plastic material used for sleeve 118, has shoulder end portions 122 and 12 enlarged with a reduced outer diameter to receive the sleeve.
The embodiment of the valve stem 120 having the valve stem 120 is molded in a surrounding relationship.

The sleeve 1.18 is molded or glued onto the outer surface of the valve stem 120. Most preferably, sleeve 118 is made of a deformable or resilient material to reduce friction between the bellows and sleeve 118.

Another embodiment of a wear surface around the valve stem is shown in FIG. The valve stem 126 is shown surrounded by a number of resilient rings 128 made of a suitable deformable material such as plastic. In one embodiment, ring 128 is unitary. Rings 128 are arranged in stacked relationship on valve stem 126.

A bellows (not shown) engages a ring 128, which serves to reduce the friction that occurs between the valve stem 126 and the bellows.

FIG. 10 shows another embodiment of a valve stem 130.

This valve stem shows an alternative embodiment of a valve stem 130 that has a wear-resistant plating layer 132 to minimize stem wear and support the bellows. In this manner, the plating 132 layer forms a metal stack on the valve stem 130 that conforms to the bent shape of the valve stem. Further, the plating layer 132 may be made of a material softer than the material of the bellows so that the plating 132 itself will wear out and the bellows surrounding the plating 132 will not wear out. In another embodiment, plating layer 132 includes bellows 58 and plating layer 1.
32M is a harder material than the material of the bellows so that strength and wear are reduced.

Another approach to preventing wear of the bellows due to frictional engagement with the valve stem is to plate the inside surface of the bellows. FIG. 6 shows bellows 134 placed in surrounding relation to valve stem 136. Bellows 134 include an inner surface that is strengthened by the addition of a plating layer 138 integrally formed with bellows 134. The plating layer 138 can be made of a material that is softer than the material of the valve stem 136 or harder than the material of the valve stem 136.

As is known, bellows are formed from a number of spirals. Due to the nature of the irregular surfaces of the plating layer of the bellows, especially the inner surface, wear of the spiral 140 is most severe and the material thickness increases on the sharply curved inner surface. Therefore, by plating the inward side of the bellows, the maximum plating layer thickness is created where wear is greatest, ie, at the spiral portion where the bellows rubs against the valve stem.

According to the present invention, the spiral structure of the bellows is designed to reduce wear on the bellows due to engagement with the valve stem. Referring to FIG. 5, there is shown a valve stem 142 surrounded by a bellows indicated generally at 144.

Bellows 144 is made of a preselected material, such as metal, and includes a number of thin turns having a preselected radius. Each spiral 146 has a vertically extending portion 1
It includes a horizontally extending surface 148 integrally formed with 50 and connecting adjacent spirals. A vertically extending or flat portion 150 extending between the spirals 146 has an inner surface disposed opposite the outer surface of the valve stem.

A suitable wear-resistant material 152 can be glued or affixed to the inner surface of the vertically extending portion 150, as shown in FIG. In this way, the spiral 14 formed in an arc shape
6 is offset from contact with the valve stem, and the axially extending portion 150 parallel to the axis of the valve stem is the only portion of bellows 134 that is engageable with the valve stem. The alignment of portion 150 parallel to the axis of valve stem 142 minimizes bellows wear by distributing the frictional engagement of valve stem 142 with bellows 144 over a larger surface area of the bellows, i.e., wear-resistant portion 150. limit.

FIG. 7 shows the bearing support of the valve stem by a number of ball bearings, generally designated 114 and 116, arranged in surrounding relation to the valve stem end portions 48 and 52.

A bellows (not shown) is disposed in surrounding relationship on the valve stem. Ball bearings 114 and 116 can be used in place of bearings 70 and 104 shown in FIG. Similarly, thrust or radial ball bearings may be used in place of bearings 96 and 100 of FIG. Ball bearings 114 and 11
6 functions as a rotating anti-wear device that operates to reduce friction. As further shown in FIG.
does not require a stem shoulder to keep the ball bearing 114 in place.

Now, referring to FIGS. 2 and 3, the valve chamber 26
A first embodiment of a device for limiting rotation of a valve actuator 30 to place a valve member 34 in an open or closed position is shown. 2 and 3 schematically illustrate the crank arm 78 by omitting the details of the connection between the valve stem 36 and the bellows 58 to the crank arm 78 in order to more clearly show the valve stop mechanism, which is generally indicated by the reference numeral 154. to show. In FIG. 3, only the lower portion 142 of the valve stem is shown. In the embodiment shown in FIGS. 2 and 3,
Valve stop mechanism 154 operates to limit rotation of actuator 38 and valve stem 36 to a 90° rotation between the open and closed positions of the valve.

As mentioned above, the crank arm 78 includes an enlarged end portion 94 that is eccentrically positioned relative to the axis of rotation of the crank arm 78. Accordingly, enlarged end portion 94 has a curved surface located in close proximity to the inner surface of actuator housing 80. Stop mechanism 15
4 includes a pair of protrusions 156 fixed to the wall of the housing 80 and extending inwardly therefrom. These projections 156 are located high on the housing 80 such that they project inwardly and oppositely from the curves of the enlarged end portion 94 . Handle 9
0 rotates, enlarged end portion 94 contacts projection 156 and prevents further rotation of crank arm 78 and valve stem 36.

Protrusion 156 is spaced apart from housing 80 to allow crank arm 78 to rotate unhindered through a 90 degree angle. When the handle 90 is rotated to the extent that the enlarged end portion 94 is in an abutting relationship with the protrusion 158, the valve structure 10 is in the closed position. Thus, when handle 90 is rotated in the opposite direction, enlarged end portion 94 is brought out of contact with projection 156 and
and eventually comes into contact with the protrusion 156. Handle 9
0 in this direction moves the valve member 34 from the open position shown in FIG. 1 to a closed position in which the valve member 34 blocks flow through the valve chamber 26.

To ensure that the aperture 44 of the valve body 40 is aligned with the flow passages 28 and 30 to open the valve 10, the protrusion 156 needs to be positioned at a selected point on the interior wall of the housing 80. , at this selected point the contact of the enlarged end portion 94 with the protrusion corresponds to the position where the through hole 44 is aligned with the channels 28 and 30. Furthermore, if the protrusion 158 is disposed on the inner wall of the housing 80, the portion on the inner wall is such that when the enlarged end portion 94 contacts the solid surface of the valve member 34,
It is necessary for the site to be moved to a position within the chamber 26 that blocks the flow between and 30. In this manner, the valve member 34 is limited to a 90° rotation with the end points of rotation of the valve member 34 coinciding with the open and closed positions of the valve.

Referring now to FIG. 4, the rotation of the valve stem 36 is restricted and the rotation of the valve member 34 is then controlled to ensure that the valve member moves reliably to the open or closed position. Another embodiment of a valve stop mechanism, generally designated 160, is shown. Valve stop mechanism 1 shown in Fig. 4
60 is a bellows plate 68 surrounding the lower end portion 48 of the valve stem.
It includes an annular recessed part 162 formed in. Bellows plate 68 is sealed to valve center disc portion 20 with a circumferential weld 74 extending around the period of bellows plate 68, or any other suitable securing seal. A pair of stop pins 164 (only one shown in FIG. 4) extend upwardly from the valve center disc portion 20 into an annular recess 162 to limit rotation of the valve stem 36 through 90 degrees. A pin 166 is secured to the lower end portion 142 of the valve stem and extends upwardly from the lower end portion 142. Pin 166 is separated from valve stem lower end portion 142 by a distance greater than the distance that stop pin 164 is separated from valve stem 36.
It has a length that extends outward from the

The retaining pin 164 is located in the annular recess 16 on the lower end portion 20 of the valve stem.
2 so that when pin 166 is in contact with either stop pin 164, valve member 3
4 is in the open or closed position. pin 16
As shown in FIG.
This corresponds to the opening position of the valve. Depending on the design clearances between several actuator parts, there can be significant "play" between the handle 90 and the valve member 34. This results in the handle 90 being rotated by more than 90 degrees, such as a rotation of 100 degrees, to move the valve member 34 into the open position or into the closed position.

However, the handle 90 has a roll bin 166 with a stop pin 1.
64 until rotation is prevented by contact with either one of them. Therefore, the handle 90 is exactly 90
The valve member 34 is not limited to rotation by 90 degrees, but the valve member 34 is surely rotated by 90 degrees, and "play" is generated in the /X handle as if the valve member 34 were to rotate to and from the open and closed positions of the valve. The person operating the valve must ensure that the handle 90 is greater than 90° between the valve's open position and the valve's open position.
Let's start by seeing how it rotates by one angle. However, the end limits of rotation of the valve member 36 accurately position the valve member in either the open or closed position.

Now, referring to FIG. 11, the bellows 58 and the valve member 3
An embodiment of a valve stem/) housing 80 surrounding the valve stem 6 is schematically shown. As shown in FIGS. 1, 3 and 4, housing 80 defines a chamber 84 around bellows 58. As shown in FIGS.

Chamber 84 serves as a secondary pressure boundary supporting the primary pressure boundary formed by bellows 58 around valve stem 36 . In operation, chamber 84 is not pressurized unless the primary pressure boundary formed by bellows 58 fails. Therefore, the first
The bellows failure indicator, shown in its entirety by reference numeral 168 in Figure 1, is /
It is provided in the A housing 80 to sense the increase in pressure within the chamber 84. The increase in pressure within chamber 84 indicates that bellows 58 is unable to prevent fluid leakage around valve stem 36. Preferably, bellows failure indicator 168 includes a pressure gauge, pressure switch, or any other suitable device operative to indicate that bellows 58 has ruptured and fluid is leaking between bellows 58 and valve stem 36. Indicator 168 is suitably connected to housing 80. The indicator 1 is connected by a hole 170 passing through the housing.
68 is influenced by the internal pressure conditions within chamber 84.

[Brief explanation of the drawing]

Claims (1)

[Claims] 1. A valve body, a flow path passing through the valve body for allowing fluid to flow, and a valve disposed in the flow path for moving between an open position and a closed position to open and close the flow path. a valve member having an axis; an actuator rotatable about an axis coaxially aligned with the axis of the member for moving the valve member between an open position and a closed position; the valve member and the actuator; a single valve stem extending between a single valve stem; a bearing structure retained on the actuator to support an upper end portion of the single valve stem for rotation relative to the actuator; and a bearing structure surrounding the single valve stem; a bellows having a lower end portion and an upper end portion; and a device for connecting the upper end portion of the bellows to the valve body to form a seal around the lower end portion of the valve stem at the valve body; wherein the single valve stem has a lower end portion non-rotationally engaged with the valve member and an upper end portion coupled to the actuator for transmitting rotation from the actuator to the valve member. an upper end portion of the valve stem is offset from a lower end portion of the valve stem, the lower end portion of the valve stem has a lower axis aligned with an axis of the valve member and an axis of the actuator; The upper end portion pivots around the valve member as the actuator rotates to move the valve member between the open and closed positions, and the bearing structure is configured to rotate the valve member when an external force is applied to the valve stem. supporting the single valve stem upper end portion to maintain the single valve stem upper end portion rotatable relative to the actuating device, the bellows upper end portion being coupled to the bearing structure to connect the bellows upper end portion and the actuating device; The valve is configured to allow relative rotation between the two and form a seal around the upper end portion of the valve stem. 2. The valve includes a guide device disposed between the valve body and the actuator for aligning the axis of the actuator with the lower axis of the valve stem. valve. 3. The valve includes a guide device disposed between the valve body and the actuating device for coaxially aligning the lower end portion of the bellows with the lower axis of the valve stem. The valve described in. 4. The bearing structure includes a bellows cap that surrounds the upper end portion of the valve stem, the bellows upper end portion is hermetically connected to the bellows cap, and the bellows cap is rotatably supported on the upper end portion of the valve stem. a first bearing member retained on the actuating device for rotatably supporting the bellows cap on the actuating device; a second bearing member retained on the actuating device to resist lateral displacement of the bellows cap; 2. The valve of claim 1, including said first and second bearing members coaxially aligned with said valve stem top portion to maintain said stem top portion parallel to the axis of said actuator. . 5. The actuating device includes a crank arm having staggered end portions having a recessed portion, the crank arm being aligned with the actuating device axis, the recessed portion being arranged such that the recessed portion axis is eccentric with respect to the axis of the actuating device. having an axis aligned with a staggered front valve stem end portion laterally from the actuator axis such that the bearing structure is retained in the recess; A valve according to claim 1, wherein the bearing structure is movable about the actuating device together with the staggered end portions of the crank arm such that the bearing structure supports the valve stem upper end portion in a track. . 6. The valve surrounds the bellows to form a supporting pressure boundary around the valve stem in addition to the pressure boundary formed by the bellows around the valve stem, and the actuating device and the valve body the actuator is rotatably supported within the housing about an actuator axis, and the valve stem upper end portion is rotatably attached to the actuator eccentrically from the actuator axis. 2. A valve according to claim 1, wherein the valve is connected and arranged so that the actuating device rotates within the housing and rotates the upper end portion of the valve stem eccentrically relative to the actuating device. 7. The valve includes a housing surrounding the bellows and extending between the actuating device and the valve body, the actuating device being rotatably supported in the housing, and the actuating device being eccentric with respect to the axis of the actuating device. 2. An end portion having an axis disposed therein, the axis of the actuator end portion being aligned with the upper axis of the valve stem for pivoting about the actuator axis. valve. 8. A stop device spaced from the housing and disposed in the orbital movement path of the actuator end portion for limiting the orbital movement of the upper end portion of the valve stem between the IHJ position and the closed position of the valve. and the valve member is configured such that upon rotation of the actuator, the actuator end portion moves into and out of contact with the stop device to close the TffIJ flow path. 8. A valve according to claim 7, operable to move in a limited orbit of rotation. 9. The valve of claim 1, wherein the upper end portion of the valve stem has an upper axis disposed in a parallel and isolated relationship with the actuator axis and the valve member axis. 10. A valve body, a flow passage passing through the valve body for allowing fluid to flow, and a valve member having a shaft disposed in the flow passage for moving between an open position and a closed position for opening and closing the flow passage. an actuator rotatable about an axis coaxially aligned with an axis of the member for moving the valve member between an open position and a closed position; and a unit extending between the valve member and the actuator. a bellows surrounding the single valve stem, wherein the single valve stem has a lower end portion non-rotatably engaged with the valve member and rotation of the actuating device an upper end portion connected to an actuator for moving the valve member to open or close the passageway, and the valve stem has an intermediate abutment portion between the upper end portion and the lower end portion. , the valve stem has a lower axis aligned with the valve member axis and the actuator axis;
The valve stem upper end portion has an upper axis offset from the actuator axis, and the intermediate target portion has an upper end aligned with the valve stem upper axis and a lower end aligned with the valve stem lower axis. to form a countercurvature in the intermediate striking portion, the countercurvature of the intermediate striking portion having a preselected radius of curvature, and the bellows matching the countercurvature radius of the valve stem. Tenaruben. 11. The valve includes a stop device spaced from and surrounding the valve body, and an abutment device associated with the valve stem for engaging the stop device to limit rotational movement of the valve stem. and wherein the stop device is disposed a preselected distance from the valve member, and the abutment device moves and closes the stop when the actuator rotates to rotate the valve stem. the valve stem is moved between an open position and a closed position such that contact with the stop device of the mating device positions the valve stem in the open position or the closed position; A valve according to claim 1, which is made possible. 12. The valve of claim 11, wherein the stop device is located on the valve body between the actuating device and the valve member. 13. A valve body, a flow path passing through the valve body for allowing fluid to flow, and a valve member disposed in the flow path to move between an open position and a closed position to open and close the flow path; an actuating device rotatable about an axis for moving the valve member between an open position and a closed position; a valve stem extending between the valve member and the actuating device; and the valve body and the actuating device. a bellows surrounding the valve stem to form a seal around the valve stem between the valve stem and the valve stem, wherein the valve stem is connected to a lower end portion connected to the valve member and from the actuator to the valve member. an upper end portion coupled to the actuating device for transmitting rotation, the upper end portion of the valve stem being displaced from the lower end portion of the valve stem to form a curved shape on the valve stem; having a curved shape corresponding to the curved shape of a valve stem, said valve stem having an outer surface, and said bellows preventing said valve stem from bending laterally when subjected to pressure to prevent distortion of said bellows. The valve has an inner surface located very close to the outer surface of the valve stem to support the bellows. 14. The lower end portion of the valve stem is displaced relative to the upper end portion of the valve stem to form a bend in the valve body between the upper end portion and the lower end portion, and the bellows is disposed very close to the valve body. The inner surface of the bellows is supported by the outer surface of the valve body along substantially its entire curved length so that the bellows are lateralized by the fluid pressure fit between the bellows and the valve stem. 14. The valve according to claim 13, which prevents the valve from bending. 15. The valve according to claim 13, including a wear-resistant plating layer disposed on the inner surface of the bellows to reduce wear on the inner surface when the inner surface of the bellows contacts the outer surface of the valve stem. , in order to reduce the 1+7 frictional contact of the curve between the valve stem and the bellows and prevent wear of the bellows, a device is provided between the outer surface of the valve stem and the inner surface of the bellows. 7. The valve according to item 13, including a coating device disposed on the outer surface of the valve stem to reduce frictional contact between the valve stem and the bellows of item 11 to prevent wear of the bellows. 14. The valve of claim 13. 18. The sheathing device includes a sleeve member surrounding and secured to the outer surface of the valve stem, the sleeve supporting the bellows on the stem. 18. The valve of claim 17, wherein the valve is adapted to reduce wear on the inner surface of the bellows due to contact with a sleeve.19. Claim 1, wherein the resilient wear-resistant material supports the bellows on the valve stem to reduce wear on the bellows inner surface due to contact with the sleeve.
The valve according to item 7. 20. The valve includes a bearing arrangement surrounding the valve stem for supporting the actuator on the valve stem to allow movement of the actuator relative to the valve stem without causing wear of the valve stem. The valve according to item 13. 21. The valve includes a plurality of ring members disposed in stacked relationship on the valve stem to support the bellows and prevent the inner surface of the bellows from contacting the outer surface of the bellows; 14. The valve of claim 13, wherein the valve is made of feed material to reduce friction and wear of the bellows due to contact with the parts. 22, the inner surface of the bellows includes a number of flat portions connected by a number of spirals, the flat portion having +f
iJ is arranged in a substantially spaced apart parallel relationship with the outer surface of the valve stem;
The -) coil is made not to come into contact with the outer surface of the valve stem, and t
14. The valve according to claim 13, wherein the flat portion is arranged to uniformly distribute the frictional engagement of the valve stem with the bellows on the surface of the flat portion along substantially the entire length of the bellows. valve. 23. The bellows has a lower end portion, a bellows plate disposed on the valve stem in surrounding relationship with the valve stem, and a first circumferential weld surrounding the bellows plate for sealingly connecting the bellows to the valve stem. and a second circumferential weld surrounding the bellows lower end iJ5 for connecting the bellows to the bellows plate to form a seal around the valve stem at the lower end portion of the bellows. The valve according to paragraph 13. 24. The valve surrounds the bellows to form a supporting pressure boundary around the valve stem in addition to the seal formed by the bellows around the valve stem between the actuating device and the valve body. a housing extending from the valve stem, a sealed chamber formed between the housing and the bellows, and associated with the housing for sensing seal failure and leakage of pressure through the bellows about the valve stem. 14. The valve of claim 13, including an indicator, and wherein said housing is operable to confine a pressure gate within said sealed chamber.