Scotch Yoke Actuator

Abstract

An embodiment of the present invention provides an actuator (100) for a valve assembly. The actuator may include a yoke (146) having at least one hole (196), a first rod assembly (136), and a first sliding member (148), the first sliding member being located in the at least one hole and pivotally connected to the first rod assembly. The yoke is configured to rotate about a yoke axis (198) to drive the valve assembly. The first rod assembly can be configured to move in a first direction transverse to the at least one hole and the yoke axis. The first sliding member can be configured to slide telescopically in the at least one hole when the first rod assembly moves in the first direction to transfer torque to the yoke for driving the valve assembly.

Description

Technical Field

[0001] The present disclosure relates to an actuator for a valve assembly, a yoke thereof, a method of reversing a rotational mode of a Scotch yoke actuator for a valve, and a method of removing a yoke of a Scotch yoke actuator for a valve. Background Art

[0002] When reciprocating rotary drive is required, rotary linear motion can be used. In some cases, a Scotch yoke actuator can be used to convert linear motion into rotary motion, including opening and closing a valve. The Scotch yoke actuator can include a housing and a rod assembly that moves back and forth in a direction transverse to the rotatable axis of the yoke offset from the rod assembly. The rod assembly can be part of a piston assembly so that linear motion of the piston of the piston assembly can cause corresponding rotary motion of the yoke through the rod assembly. The housing is generally sized to enclose the yoke in any operating rotational orientation. Summary of the Invention

[0003] Some embodiments of the present invention provide an actuator for a valve assembly. The actuator may include a yoke, a first rod assembly, and a first sliding member. The yoke may include at least one hole and may be configured to rotate about a yoke axis to drive the valve assembly. The at least one hole may extend transversely to the yoke axis. The first rod assembly may be configured to move in a first direction transverse to the at least one hole and the yoke axis. The first sliding member may be located in the at least one hole and be pivotally fixed to the first rod assembly. The first sliding member may be configured to slide telescopically in the at least one hole when the first rod assembly moves along the first direction to transfer torque to the yoke for driving the valve assembly.

[0004] Some embodiments provide an actuator having a first sliding member, the first sliding member including a first free end pivotally secured to a first rod assembly and a second free end telescopically engageable with at least one aperture formed in a yoke. The first free end of the first sliding member can be pivotally secured to the first rod assembly via a pivotal connection to a connecting arm, the connecting arm being threadedly engaged with the first rod assembly.

[0005] Some embodiments provide an actuator including a first rod assembly. The first rod assembly may include a piston rod of a cylinder assembly, the piston rod being configured to controllably move the first rod assembly in a first direction.

[0006] Some embodiments provide an actuator comprising a piston rod slidably supported by a sliding bushing. The piston rod may be a stepped rod, wherein a shoulder of the stepped rod contacts the sliding bushing after a predetermined movement in a first direction, causing the sliding bushing to slide in the first direction.

[0007] Some embodiments provide an actuator comprising a housing at least partially surrounding a yoke, a first rod assembly, and a first sliding member. The first rod assembly can extend across the housing transverse to the yoke axis and can be slidably supported on opposite sides of the housing for movement in the first direction.

[0008] Some embodiments provide an actuator including a housing. The housing may include a housing shell open on opposite sides, a first end cap, and a second end cap. The first and second end caps may slidably support a first rod assembly.

[0009] Some embodiments provide an actuator comprising a first end cap capable of supporting a linear actuator relative to a housing. The linear actuator can move a first rod assembly in a first direction. The end cap can be configured to be secured to the housing in either of two orientations to provide the yoke with either of two opposing rotational modes.

[0010] Some embodiments provide an actuator including a rod assembly. The rod assembly may include a piston rod extending through a first side opposite to the housing. The rod assembly may include a connecting arm threadedly secured to the piston rod and pinned to the first sliding member. The rod assembly may include a guide rod threadedly secured to the connecting arm opposite to the piston rod and extending through a second side opposite to the housing. The piston rod may be slidably supported by a first end cap, and the guide rod may be slidably supported by a second end cap.

[0011] Some embodiments provide an actuator comprising a stop sleeve threadably engaged with a housing of the actuator (e.g., an end cap of the housing). A rod assembly can extend through the stop sleeve. The stop sleeve is threadably adjustable relative to the housing to adjust a position of a stopper of the rod assembly relative to movement of the rod assembly in a first direction.

[0012] Some embodiments provide an actuator including a stop sleeve. The stop sleeve may include a first side configured to contact a first portion of a rod assembly to provide a first stop. A second side of the stop sleeve may be configured to contact a second portion of the rod assembly to provide a second stop.

[0013] Some embodiments provide an actuator comprising a first rod assembly and a second rod assembly. The second rod assembly may be configured to move in a second direction, the second direction being transverse to at least one hole formed in the yoke and transverse to the yoke axis. The actuator may include first and second sliding members. The second sliding member may be seated in the at least one hole and pivotally secured to the second rod assembly. When the second rod assembly moves in the second direction, the second sliding member may be configured to slide telescopically within the hole to transfer torque to the yoke, thereby driving the valve assembly. The hole may include a first hole that receives the first sliding member at its first end and receives the second sliding member at its second end.

[0014] Some embodiments provide an actuator comprising a yoke having a hole, the hole comprising a slot. A pin may extend from a first sliding member to slidably engage the slot. The slot may be a closed-end slot.

[0015] Some embodiments of the present invention provide a yoke for an actuator of a valve assembly. The yoke may include a valve engaging portion and a rod fixing portion. The valve engaging portion may be configured to engage with a valve member so as to rotate the valve member via the actuator. The rod fixing portion may be formed separately from the valve engaging portion. The rod fixing portion may be fixed to the valve engaging portion so as to define a channel between the rod fixing and valve engaging portions on first and second opposite sides of the channel. The channel may be sized to receive one or more sliding members through at least one of the third or fourth opposite sides of the channel, the sliding members being pivotally fixed to one or more rod assemblies of the actuator such that sliding motion of the one or more rod assemblies is converted into torque on the yoke via sliding motion of the one or more sliding members within the channel along the bearing component. The channel may be sized to receive two sliding members for opposite, parallel and overlapping motions.

[0016] Some embodiments of the present invention provide a method for reversing the rotational mode of a Scotch yoke actuator for a valve. The method may include disconnecting a connecting arm from a first sliding member, the connecting arm being disposed within a housing of the actuator and pivotally supporting the first sliding member for telescopic movement within a corresponding aperture of a yoke of the actuator prior to disconnection. The method may include removing the connecting arm and a linear actuator from a first side of the housing near a first inlet of the housing, for applying torque to the yoke via the actuator and the connecting arm. The method may include inserting the connecting arm into a second inlet of the housing on the first side of the housing without reversing the orientation of the housing, and securing the linear actuator to the housing near the second inlet. The method may include connecting the connecting arm to a second sliding member within the housing so that the second sliding member can telescopically move within the yoke. The method may also include unscrewing a first guide rod from engagement with the connecting arm before removing the actuator from near the first inlet, and threadably engaging the first or second guide rod with the connecting arm after inserting the connecting arm into the second inlet.

[0017] Some embodiments of the present invention provide a method for removing a yoke from a Scotch yoke actuator for a valve. The method may include unscrewing an actuator rod of a linear actuator from an engagement with a connecting arm disposed within a housing of the actuator and pivotally supporting a sliding member for telescopic movement of the sliding member within a corresponding aperture in the yoke. The method may include removing a top cover of the housing to provide a top opening in the housing without removing the linear actuator from the housing or removing side walls of the housing that support the actuator and the actuator rod during operation. The method may include removing the yoke through the top opening.

[0018] Some embodiments of the present invention provide an actuator for a valve assembly. The actuator may include a yoke, a rod assembly, and a sliding member. The yoke may include a channel. The yoke may be configured to rotate about a yoke axis to drive the valve assembly, and the channel may extend from a peripheral edge of the yoke toward the yoke axis. The rod assembly may be configured to move in a first direction transverse to the channel and the yoke axis. The sliding member may be pivotally fixed to the rod assembly at a first end and extend from the first end toward the yoke axis to a second end of the sliding member, the second end being opposite to the first end and slidingly engaged with the channel. Movement of the rod assembly in the first direction may cause the sliding member to pivot relative to the rod assembly at the first end and slide within the channel at the second end, thereby providing torque on the yoke.

[0019] Some embodiments of the present invention provide an actuator for a valve assembly. The actuator may include a yoke, a rod assembly, and a sliding member. The yoke is configured to rotate about a yoke axis to drive the valve assembly. The rod assembly may be configured to move in a first direction transverse to the yoke axis. The sliding member may be pivotally fixed to the rod assembly at a first end and extend from the first end toward the yoke axis to a second end of the sliding member, the second end being telescopically engaged with the yoke axis. The sliding member may thus be configured to exhibit a varying angle relative to the rod assembly and a corresponding varying telescopic depth of engagement with the yoke when the rod assembly moves in the first direction to provide torque on the yoke. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is an exploded isometric view of an actuator for a valve assembly according to an embodiment of the present invention.

[0021] Figure 2 yes Figure 1 Exploded side view of the cylinder assembly of the actuator.

[0022] Figure 3 yes Figure 1 An exploded isometric view of the housing, yoke, and rod assemblies of an actuator.

[0023] Figure 4 yes Figure 3 Exploded isometric view of the housing assembly.

[0024] Figure 5 yes Figure 3 An isometric drawing of the yoke assembly of the yoke.

[0025] Figure 6 yes Figure 1 Isometric drawing of the sliding member of the actuator.

[0026] Figure 7 yes Figure 3 Isometric drawing of the connecting arm of the rod assembly.

[0027] Figure 8 yes Figure 3 Isometric view of a yoke assembly and a fixing tool according to an embodiment of the present invention.

[0028] Figure 9 is fixed Figure 8 A cross-sectional isometric view of the connecting arm on the yoke assembly.

[0029] Figure 10 is fixed Figure 1 Isometric view of the rod assembly on the yoke assembly of the actuator.

[0030] Figure 11is fixed Figure 1 An isometric partial view of the cylinder assembly on the yoke assembly of the actuator, wherein Figure 3 The cover of the housing assembly is removed.

[0031] Figure 12 It is along Figure 11 A cross-sectional isometric partial view of the cylinder assembly secured to the yoke assembly, taken along line 12-12.

[0032] Figure 13 yes Figure 1 Isometric diagram of the actuator, Figure 3 The cover of the housing assembly is removed.

[0033] Figure 14 is an exploded isometric view of an actuator for a valve assembly according to another embodiment of the present invention.

[0034] Figure 15 yes Figure 14 Exploded isometric view of the actuator's yoke and housing assembly.

[0035] Figure 16 yes Figure 14 Isometric diagram of the actuator.

[0036] Figure 17 It is along Figure 16 The 17-17 line is intercepted Figure 14 Top cross-sectional view of the actuator.

[0037] Figure 18A yes Figure 14 Top cross-sectional partial view of the actuator in 0-degree rotational orientation.

[0038] Figure 18B yes Figure 14 Top cross-sectional partial view of the actuator in a 45-degree rotated orientation.

[0039] Figure 18C yes Figure 14 Top cross-sectional partial view of the actuator in a 90-degree rotated orientation.

[0040] Figure 19A yes Figure 14 A top cross-sectional partial view of the cylinder assembly of an actuator with the piston rod extending through the sliding bushing in a first position.

[0041] Figure 19B yes Figure 19A A top cross-sectional partial view of a cylinder assembly with the piston rod extending through the sliding bushing in a second position.

[0042] Figure 19C yes Figure 19AA top cross-sectional partial view of a cylinder assembly with the piston rod extending through the sliding bushing in a third position.

[0043] Figure 20 is a top view of a yoke assembly in a first position according to an embodiment of the present invention.

[0044] Figure 21 yes Figure 20 An isometric drawing of the yoke assembly of the yoke.

[0045] Figure 22 yes Figure 20 Isometric drawing of the sliding member of the yoke assembly.

[0046] Figure 23 yes Figure 20 A top view of the yoke assembly in the second position.

[0047] Figure 24 is an isometric view of a yoke assembly according to another embodiment of the present invention.

[0048] Figure 25 is an isometric view of a yoke assembly according to another embodiment of the present invention.

[0049] Figure 26 is a partial cross-sectional isometric view of a yoke assembly according to another embodiment of the present invention.

[0050] Figure 27 is a partial cross-sectional isometric view of a yoke assembly according to another embodiment of the present invention.

[0051] Figure 28 is an isometric view of a yoke assembly according to another embodiment of the present invention.

[0052] Figure 29 is an isometric view of a yoke assembly according to another embodiment of the present invention.

[0053] Figure 30A is a top view of a yoke assembly within a housing according to one embodiment of the present invention, the yoke assembly being in a 0 degree rotational orientation.

[0054] Figure 30B yes Figure 30A A top view of a yoke assembly, wherein the yoke assembly is in a neutral rotational orientation.

[0055] Figure 30C yes Figure 30A and 30B A top view of a yoke assembly, wherein the yoke assembly is in a 45-degree rotated orientation.

[0056] Figure 31 is a flow chart illustrating a method of reversing the rotational mode of a Scotch yoke actuator of a valve.

[0057] Figure 32 is a flow chart illustrating a method of removing a yoke of a Scotch yoke actuator of a valve. DETAILED DESCRIPTION

[0058] Before explaining any embodiment of the present invention in detail, it should be understood that the application of the present invention is not limited to the details of the construction and component arrangement set forth in the following description or shown in the following drawings. The present invention can have other embodiments and can be practiced or implemented in various ways. In addition, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered restrictive. The use of "comprising", "including" or "having" and its variations herein is intended to cover the items listed thereafter and their equivalents and additional items. Unless otherwise specified or limited, the terms "mount", "connect", "support" and "couple" and their variations are used broadly and cover direct and indirect mounting, connection, support and coupling. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings.

[0059] In general, unless otherwise specified or limited, directional terminology herein is used only to illustrate directions or specific illustrations and is not intended to indicate absolute orientations. For example, some components may be described as "upper" or "lower" components, which may indicate the position of these components relative to other components in a given (e.g., illustrated) configuration, but this does not necessarily limit these components to absolute positions. Similarly, unless otherwise specified or limited, angular references are only for example orientations or specific illustrations and are not intended to indicate absolute orientations.

[0060] The following discussion is presented to enable those skilled in the art to make and use embodiments of the present invention. Those skilled in the art will readily appreciate the various modifications to the illustrated embodiments, and the general principles herein can be applied to other embodiments and applications without departing from embodiments of the present invention. Therefore, embodiments of the present invention are not intended to be limited to the embodiments shown, but should be given the widest scope consistent with the principles and features disclosed herein. The following detailed description will be understood with reference to the accompanying drawings, in which similar elements in different drawings have similar reference numerals. The accompanying drawings, which are not necessarily drawn to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the present invention. Those skilled in the art will recognize that the examples provided herein have many useful alternatives and are within the scope of embodiments of the present invention.

[0061] Embodiments of the present invention generally relate to an actuator for a valve assembly, including those described in further detail below. As briefly described above, actuators, particularly Scotch yoke actuators, can be used to convert linear motion into rotational motion. Although other configurations are possible, Scotch yoke actuators typically provide a rotational range of approximately 90 degrees, with torque being higher at the ends of the yoke stroke (e.g., at or near 0 and 90 degrees of rotational orientation about the yoke axis) and lower in the middle of the yoke stroke (e.g., at a 45-degree rotational orientation about the yoke axis). These torque curve characteristics are particularly advantageous for some operations, including the actuation of some valves.

[0062] A Scotch yoke actuator typically includes a housing with a rod assembly that moves linearly relative to a yoke that defines an axis of rotation. The actuator may also include a linear actuator, such as a spring-cylinder assembly (i.e., a piston). One end of the rod assembly may be coupled to the spring cylinder, and the other end of the rod assembly may be coupled to the yoke. Thus, force imparted to the rod assembly by the linear actuator can be transferred to the yoke and converted into torque (e.g., opening or closing a valve).

[0063] In some Scotch yoke actuators, the spring in the spring cylinder can be compressed due to pneumatic pressure acting on the cylinder's piston, thereby simultaneously rotating the yoke in a first direction. During the return stroke, as the pneumatic pressure is released, the compressed spring can expand, thereby moving the piston away from the yoke and simultaneously rotating the yoke in a second direction. Thus, for example, such an actuator can have a default (e.g., "off") orientation, as defined by the spring's rest (e.g., uncompressed) position.

[0064] In some Scotch yoke actuators, the housing surrounding the yoke includes: an extension on one or more sides of the housing to accommodate the space required for the yoke; a push rod assembly; and a connection mechanism positioned between the two during yoke rotation. Consequently, some housings for Scotch yoke actuators may require a significant amount of mounting space and, consequently, may include a significant amount of material, resulting in a significant overall weight.

[0065] In some cases, the extension of the housing and spring cylinder assembly can also result in increased cantilever loads on the housing or rod assembly, for example, in the latter case, which can result in lower operating efficiency and reduced operating life.

[0066] Furthermore, some Scotch yoke actuators require complex or otherwise time-consuming operations for maintenance or reconfiguration. For example, in conventional designs, the actuator (e.g., the spring-cylinder assembly) may need to be removed from the housing to replace internal actuator components, such as the yoke seal or bushing. Removing the spring-cylinder assembly from the housing before the entire housing can be disassembled can be a time-consuming process. Furthermore, switching between clockwise and counterclockwise failure directions in conventional Scotch yoke actuators may require reversing the orientation of the entire actuator assembly and actuator housing. This can also be time-consuming.

[0067] Thus, in general, it may be useful to reduce the size of a Scotch yoke actuator to fit within limited installation spaces, reduce system weight, and reduce costs associated with manufacturing. It may also be useful to improve (e.g., reduce) stress concentrations in the actuator, including those in the yoke, rod assembly, and housing. It may also be useful to provide simplified methods for assembling, maintaining, and reversing the rotational mode (e.g., failure direction) of a Scotch yoke actuator. Embodiments of the present invention may provide one or more of these advantages, or various other advantages, while retaining other favorable aspects of the general Scotch yoke design (e.g., the torque characteristics described above).

[0068] In some embodiments, improvements in size, stress distribution, and assembly / maintenance can be achieved by using a telescoping assembly. For example, the yoke of a Scotch yoke actuator can include a channel (e.g., a cylindrical bore) extending transversely relative to the axis of rotation of the yoke. The rod assembly can pivotally support a sliding member that extends transversely relative to the axis of the rod assembly (and relative to the yoke axis) and is sized to be received and slide within the channel of the yoke. When the rod assembly moves relative to the yoke, for example, via linear motion driven by a linear actuator, the sliding member can rotate relative to the rod assembly, thereby applying torque to the yoke while sliding within the yoke channel. Thus, for example, linear motion of the rod assembly can be converted into torque on the yoke, but with a reduced overall footprint and improved stress distribution (e.g., reduced lateral loads on the rod assembly) compared to conventional arrangements. Furthermore, in some embodiments, the telescoping arrangement can facilitate installation and maintenance operations, including operations to change (e.g., reverse) the rotational mode of the actuator.

[0069] Figure 1A cross-sectional view of an actuator 100 for a valve assembly according to one embodiment of the present invention is shown. The actuator 100 includes, among other components, a cylinder assembly 102, a housing assembly 104, and a yoke assembly 106. In the illustrated embodiment, the actuator 100 includes first and second cylinder assemblies 102 that are substantially identical (i.e., identical within tolerances acceptable for conventional manufacturing processes) and can be mounted on opposite sides of the housing assembly 104. Therefore, the following discussion regarding a single cylinder assembly 102 generally applies equally to both cylinder assemblies 102. However, in some embodiments, only a single cylinder assembly may be provided, or the multiple cylinder assemblies may be substantially identical to one another. Furthermore, some embodiments may include one or more other types of actuators (e.g., other linear actuators) in addition to or in place of one or more cylinder assemblies.

[0070] Figure 2 The actuator 100 is shown (see Figure 1 ). The cylinder assembly 102 includes a cylinder body 112 that generally defines a middle end 114 and a lateral end 116 relative to the housing assembly 104 (i.e., the middle end 114 is secured adjacent the housing assembly 104). The cylinder body 112 is sized to receive a spring 118, a piston rod 120 having a threaded end 132, and a piston head 122. The cylinder assembly 102 also includes an annular sealing member 124 that is seated between an outer piston end cap 126 and the cylinder body 112 at the lateral end 116. The outer piston end cap 126 and the inner piston end cap 128 are each configured to receive a plurality of fasteners 130 to secure the cylinder body 112 between the outer piston end cap 126 and the inner piston end cap 128. In the illustrated embodiment, the fasteners 130 are configured as a plurality of tie rods having opposing threaded ends, although other configurations are possible. The threaded ends are sized to receive nuts to secure each of outer piston end cap 126 and inner piston end cap 128 relative to the plurality of rods of fastener 130 .

[0071] Figure 3 The housing assembly 104 and yoke assembly 106 of the actuator 100 are shown, along with a rod assembly 136. In the illustrated embodiment, the actuator 100 includes first and second rod assemblies 136, which are substantially identical (i.e., identical within tolerances acceptable for conventional manufacturing processes) to the cylinder assemblies 102 and mounted on opposite sides of the housing assembly 104. The rod assemblies 136 are in communication with a respective one of the two cylinder assemblies 102. Therefore, the following discussion of a single rod assembly 136 generally applies equally to both rod assemblies 136. However, in some embodiments, only a single rod assembly may be provided, such as in the case of a single cylinder assembly. In other embodiments, the rod assemblies may be substantially different from one another.

[0072] Still refer to Figure 3 , the housing assembly 104 includes a base 140 (e.g., a cast metal base) and a cover 142. The yoke assembly 106 includes a yoke 146, a sliding member 148, and a slider pin 150. In particular, in the illustrated embodiment, the yoke assembly 106 includes a pair of sliding members 148 and sliding pins 150. However, in some embodiments, such as in the case of a single cylinder assembly, the yoke assembly 106 may include a single sliding member and a corresponding single slider pin (or other similar components). Figure 3 , the rod assembly 136 includes a piston rod 120, a guide rod 154, and a connecting arm 156. Similar to the piston rod 120, the guide rod 154 includes a threaded end 158. Accordingly, as described below, the connecting arm includes opposing threaded holes that can be threadedly engaged with the threaded ends 132, 158 of the piston and guide rods 120, 154 to secure the guide rod assembly 136 together for unified movement.

[0073] Figure 4 The housing assembly 104 of the actuator 100 is shown. The base 140 of the housing assembly 104 is configured as a housing shell having a set of opposing sidewalls, including a first set of opposing sidewalls 160. The sidewalls 160 are substantially identical, with each first set of opposing sidewalls 160 including a first channel 162 and a second channel 164. Each of the first channel 162 and the second channel 164 defines a substantially parallel central axis. Furthermore, the axes of the first channels 162 are aligned, and the axes of the second channels 164 are aligned. Each of the first and second channels 162, 164 extends through a respective boss that extends outward from the base 140, providing a protruding feature on the respective sidewall 160. In some embodiments, there may be more or fewer channels. For example, the opposing sidewalls of the housing shell may each include a channel. Similarly, in other embodiments, openings of other shapes or positions may be used to provide access to the housing.

[0074] The base 140 of the housing assembly 104 also includes a second set of opposing side walls 166 that are generally perpendicular to the first set of opposing side walls 160. The base 140 also includes a bottom surface 168 that is generally orthogonal to each pair of opposing side walls 160, 166. The bottom surface 168 includes a yoke aperture 170 that is sized to receive one end of the yoke 146 (see, e.g., Figure 3 In the illustrated embodiment, each opposing sidewall 160, 166 of the base 140 includes one or more first mounting features 172. The cover 142 of the housing assembly 104 also includes a plurality of second mounting features 174. The first mounting features 172 generally correspond to the second mounting features 174 so that one or more fasteners can extend therethrough to secure the cover 142 to the base 140 of the housing assembly 104.

[0075] Still refer to Figure 4 The housing assembly 104 is configured to receive a set of end caps 180, 182. The end caps 180 are formed as cylindrical plates that are configured to be secured to a boss on the housing assembly 104 in alignment with the passage 164 and also secured to the cylinder assembly 102 in alignment with the rod assembly 136 to support the cylinder assembly 102 relative to the housing assembly 104, thereby slidably supporting the rod assembly 136 relative to the housing assembly 104. The end caps 182 are formed as rectangular plates that are configured to be secured to a boss on the housing assembly 104 in alignment with the passage 162 to slidably support the rod assembly 136 relative to the housing assembly 104. As discussed further below, the end caps 180, 182 can be interchanged between the illustrated positions to change the rotational mode of the actuator 100 (e.g., both end caps 180 are secured in a position aligned with the passage 162, and both end caps 182 are secured in a position aligned with the passage 164). Furthermore, while the illustrated geometry of the end caps 180, 182 is useful with respect to structural stability and ease of manufacture, other embodiments may utilize different shapes or sizes.

[0076] like Figure 4 As shown, inner piston end cap 128 includes a through-hole 186 that defines an end cap axis. Furthermore, through-hole 186 is sized to provide lateral support to rod assembly 136 during operation. Similarly, each end cap 182 includes a through-hole (e.g., via a circular boss, as shown) that also defines an end cap axis and can slidably receive and provide lateral support for rod assembly 136 relative to end caps 128, 180. The mounting features of end cap 180 are configured to secure end cap 180 and inner piston end cap 128 relative to either the first or second channels 162, 164. The mounting features of end cap 182 are configured to secure end cap 182 relative to the other of the first or second channels 162, 164. For each set of channels 162 or 164, the end cap axes of end caps 128, 180, 182 (when in a secured position) are configured to align with the respective central axes of the corresponding channels 162, 164 and with each other.

[0077] In the illustrated embodiment, for example, one set of end caps 180, 182 is aligned with the first passages 162 of the opposing sidewalls 160, and the other set of end caps 180, 182 is aligned with the second passages 164 of the opposing sidewalls 160, with the end caps 180 (and inner piston end cap 128) being located on opposite sides of the housing assembly 104. However, as described above, in other embodiments or arrangements, each end cap 180, 182 (and 128) can be aligned with the other of the respective first and second passages 162, 164. Furthermore, in some embodiments, other features (e.g., features on the end caps 180) can provide lateral support as the rod assembly 136 slides through the corresponding passages 162, 164.

[0078] Figure 5 The yoke 146 of the yoke assembly 106 is shown. The yoke 146 includes a valve engaging portion 192 and a stem securing portion 194 defining a bore 196. In the illustrated embodiment, the bore 196 extends completely through the stem securing portion 194 along a single axis (e.g., see FIG. Figure 9 ). However, in some embodiments, the yoke may include a rod-fixing portion that defines a separate first hole and a second hole. For example, the first and second holes may extend only partially through the yoke along a common axis or different axes, extend in opposite directions, or may extend completely through the yoke along different axes. Furthermore, in some embodiments, the hole may include one or more of a variety of hole geometries. For example, the cross-section of the hole may have a regular geometry, such as a circle, a rectangle, a triangle, etc., or an irregular geometry, and different holes may have the same or different cross-sections along their respective lengths. The yoke 146 defines a yoke axis 198, the yoke 146 is configured to rotate about the yoke axis to drive the valve assembly, and the hole 196 extends transverse to the yoke axis 198 (e.g., perpendicular to the yoke axis 198, as shown).

[0079] In some embodiments, the yoke defining the bore may include a groove or slot near the outer end of the bore extending toward the yoke axis. For example, the bore 196 includes a groove 202 formed at the outer end of the inner bore 196. The groove 202 generally provides clearance for the slider pin 150 and the rod assembly 136 (e.g., see FIG. Figure 9 ), because when the actuator 100 is assembled, the yoke 146 rotates about the yoke axis 198. In some cases, the groove 202 can help relieve stress concentrations in the yoke 146, particularly in the rod-securing portion 194. In this regard, for example, it may be useful for the outer wall of the hole 196 to completely include the groove 202 (as shown) so that the groove 202 does not interrupt the outer annular profile of the yoke 146 around the hole 196. However, in some embodiments, such an outer annular profile may be interrupted, or the hole or other passage in the yoke may not include a groove or slot.

[0080] Figure 6The sliding member 148 of the yoke assembly 106 is shown. The sliding member 148 includes a first free end configured as a sliding portion 208 and a second free end configured as a fixed portion 210. The sliding portion 208 is generally configured as a cylindrical body sized to be received by the aperture 196 of the yoke 146. In particular, the fixed portion 210 includes a clevis structure 212 that is configured to secure the connecting arm 156 to the sliding member 148 via the slider pin 150. However, in other embodiments, other configurations are possible. For example, the connecting arm may include a similar clevis structure that receives an extension of the sliding member.

[0081] Figure 7 The connecting arm 156 of the lever assembly 136 is shown. The connecting arm 156 includes opposite ends 218 and a pivot portion 220 located between the opposite ends 218. Each of the opposite ends 218 includes a threaded bore 222 that extends at least partially from the respective opposite end 218 toward the pivot portion 220. The pivot portion 220 includes a pivot bore 224 that extends transversely to the threaded bore 222 and is sized to receive the slider pin 150 to secure the sliding member 148 to the connecting arm 156. In other embodiments, other configurations are possible, including various known structures for securing a sliding member or lever assembly rod to a corresponding portion of the connecting arm.

[0082] Figure 8 An example arrangement of the connecting arms 156 and the yoke assembly 106 in a pre-installed configuration and a corresponding example assembly method are shown. As described above, each connecting arm 156 can be secured to the yoke assembly 106 via the securing portion 210 of the sliding member 148. In particular, the pivot portion 220 of the connecting arm 156 can be inserted into the clevis structure 212 of the sliding member 148. The slider pin 150 can be partially inserted into one side of the clevis structure 212 (e.g., prior to inserting the pivot portion 220 of the connecting arm 156 into the clevis structure 212, such that it can be staggered to facilitate subsequent insertion). Once the pivot hole 224 is aligned within the clevis structure 212, a tool, such as a pin installation tool 228, can be inserted into the other side of the clevis structure 212 and engage the slider pin 150 through the pivot hole 224 (e.g., via threads). Once the pin installation tool 228 is secured to the slider pin 150, the pin installation tool 228 can be used to move the slider pin 150 through the clevis structure 212 and, thereby, through the pivot hole 224 to pivotally couple the connecting arm 156 to the yoke assembly 106. Once the slider pin 150 is extended through the clevis structure 212 and the pivot hole 224, the pin installation tool 228 can be removed from the slider pin 150, and the retainer 230 (e.g., an E- or C-clip) can engage and secure the slider pin 150 relative to the slide member 148.

[0083] Figure 9A cross-section of the yoke assembly 106 and connecting arm 156 in the installed configuration is shown. As briefly described above, the aperture 196 provides a passage extending through the yoke 146. Furthermore, the aperture 196 is sized to slidably receive each sliding portion 208 of the sliding member 148 at its opposite ends. Thus, the sliding members 148 can be nested within the aperture 196 and can independently slide along their respective sliding portions 208 within the aperture 196 (i.e., can be telescopically movable with the aperture 196). Thus, generally speaking, during operation, the sliding members 148 move toward and away from the yoke shaft 198 and laterally thereon. In the illustrated configuration, the sliding members 148 are fully retracted into the aperture 196, which generally corresponds to a 45-degree orientation of the actuator 100, although other configurations are possible.

[0084] exist Figure 9 In the illustrated configuration, each slider pin 150 is seated within a respective recess 202 of a respective slide member 148. By sizing each recess 202 to receive a slider pin 150, each connecting arm 156 can be positioned closer to the yoke shaft 198 when the yoke 146 is in a 45-degree (or other fully telescoping) orientation. By reducing the distance between the connecting arm 156 and the yoke shaft 198, the maximum space required for the yoke assembly 106 and the rod assembly 136 in a direction transverse to the yoke shaft 198 can be correspondingly reduced, thereby allowing for a more compact housing.

[0085] Figure 10 The yoke assembly 106 is shown pinned to one rod assembly 136. Another rod assembly (not shown) may be secured to the yoke assembly 106 in a substantially similar manner (e.g., see Figure 12 ), therefore, the description of the rod assembly 136 and its attachment to the yoke assembly 106 can be applied to the other rod assembly 136. In the illustrated embodiment, the piston rod 120 is attached to the connecting arm 156 by threaded engagement of the threaded end 132 of the piston rod 120 with the threaded hole 222 of the connecting arm 156. Similarly, the guide rod 154 is attached to the connecting arm 156 by threaded engagement of the threaded end 158 of the guide rod 154 with the threaded hole 222 of the connecting arm 156.

[0086] Generally speaking, the piston rod 120 of the rod assembly 136 is configured to controllably move one rod assembly 136 along the axis of the rod assembly 136 (e.g., to open the valve in a first linear direction during actuation). When one rod assembly 136 is moved by the piston rod 120 (e.g., transverse to the yoke axis 198, see Figure 9), the corresponding sliding member 148 can pivot relative to the yoke 146 at the fixed portion 210 of the sliding member 148, thereby changing the angle of the sliding member 148 relative to the rod assembly 136 and allowing the sliding member 148 to slide telescopically within the bore 196. Thus, the sliding member 148 can transfer the linear motion of the rod assembly 136 to torque on the yoke 146 to actuate the valve assembly without impeding the motion of the rod assembly 136 or applying significant lateral loads to the rod assembly 136. Furthermore, because the extended length of the sliding member 148 allows for effective engagement with the yoke 146 at the bore 196, even at the minimum telescoping depth within the bore 196, the overall lateral dimension of the yoke 146 (i.e., along the bore 196) can be significantly reduced relative to conventional designs (e.g., having a pin and slot configuration). Accordingly, as similarly discussed above with respect to the recess 202, the illustrated design can allow for the use of a significantly smaller housing than would be required with conventional designs.

[0087] Figure 11 and 12 The yoke assembly 106 and each rod assembly 136 are shown at least partially enclosed within the housing assembly 104. Further illustrated is one of the cylinder assemblies 102 secured to the housing assembly 104. The other cylinder assembly 102 ( Figure 11 and 12 ) can be secured to the housing assembly 104 in a substantially similar manner (e.g., see Figure 13 ), therefore, the description of the cylinder assembly 102 and its attachment to the housing assembly 104 may apply to another cylinder assembly 102.

[0088] Generally speaking, the rod assembly 136 extends through the base 140 of the housing assembly 104, extends transversely to the yoke shaft 198, and is slidably supported on each of the first pair of opposing side walls 160. Thus, for example, the above-mentioned Figure 10 The driving motion can be achieved with significantly higher efficiency and significantly lower wear (eg, due to reduced lateral loading of the rod assembly 136).

[0089] In particular, in the illustrated embodiment, the inner piston end cap 128 is secured to the end cap 180 to secure the cylinder assembly 102 to the housing assembly 104. The piston rod 120 extends through the through hole 186 (see FIG. Figure 4 ), through the second channel 164 (see Figure 4 ) passes through one of the first pair of opposite sides 160 of the base 140 and is threadedly fixed to the connecting arm 156. Therefore, the linear force from the cylinder assembly 102 can be efficiently transmitted to the connecting arm 156, so that the corresponding sliding member 148 can transmit the torque to the yoke 146.

[0090] Generally speaking, it may be beneficial to slidably support the rod assembly 136 on at least one side, and in some cases both sides, of the housing assembly 104. In the illustrated example, the piston rod 120 is slidably supported by the inner piston end cap 128, which is also discussed above. In addition, the guide rod 154 is threadedly secured to the connecting arm 156 opposite the piston rod 120 and extends through the other of the first pair of opposite sides 160 of the base 140 through the opposite passage 164 (see FIG. 1 ). Figure 4 In particular, the guide rods 154 are slidably supported by the end caps 182 (also discussed below), and thus, the guide rod assembly 136 is slidably supported on both sides of the housing assembly 104, and lateral deformation of the guide rod assembly 136 can be substantially avoided. However, in other embodiments, the guide rods may not be included, or the guide rod assembly may be slidably supported in another manner.

[0091] Still refer to Figure 11 and Figure 12 , the rod assembly 136 further includes a limiting sleeve 238. In particular, in the illustrated embodiment, the actuator 100 includes a pair of limiting sleeves 238, which are connected to a pair of rod assemblies 136 (see FIG. Figure 1 ) corresponding to the guide rods 154. Accordingly, each guide rod 154 can be extended by a respective stop sleeve 238. Furthermore, each stop sleeve 238 can be threadably adjusted relative to the housing assembly 104 to adjust the position of the stopper relative to the linear movement of each rod assembly 136, thereby limiting the rotational movement of the yoke 146. For example, by adjusting the stop sleeve 238 to extend further into the housing 104, movement of the rod assembly 136 away from the cylinder assembly 102 can be stopped earlier (e.g., by contact between the stop sleeve 238 and the connecting arm 256 or other features of the rod assembly 236). Furthermore, in some embodiments, a single stop sleeve can limit rotation in both directions. For example, a nut 242 or other feature on one or more guide rods 154 can be configured to contact the corresponding outer side of the associated stop sleeve 238 (e.g., at a distance controlled by adjustment of the nut 242 along the guide rod 154), thereby controllably limiting movement of the rod assembly 136 toward the cylinder assembly 102.

[0092] In different embodiments, different structures can be used to fix and adjust the limit sleeves and corresponding limit positions. For example, in the illustrated embodiment, each limit sleeve 238 directly and threadedly engages with the corresponding end cap 182 and also extends through a respective nut 240. Therefore, the position of the limit sleeve 238 relative to the housing assembly 104 can be adjusted by rotating the limit sleeve 238 and then locked by tightening the nut 240. The nut 242 can also be similarly adjusted (and locked as needed), as described above. However, in other embodiments, other configurations are feasible.

[0093] In some embodiments, the use of a stop collar 238 or other similar structure can also improve the overall structure of the actuator 100. For example, by eliminating the need for conventional extended side features on the yoke 146 to provide stop contact, the space required for yoke 146 rotation can be reduced, thereby reducing the overall size of the housing assembly 104. Furthermore, compared to conventional designs, the stop collar 238 provides a smaller number of stop contact and adjustment points, and these stop contact and adjustment points are also aligned along the axis of motion of the corresponding rod assembly 136, rather than offset from it. This allows for simpler—and therefore less error-prone—adjustment to the extremes of the yoke 146's rotational range, as well as improved overall stress distribution, including by eliminating the potential for off-axis loading on the housing assembly 104 due to misalignment of multiple stop collars on one of the rod assemblies 136.

[0094] Notably, the illustrated embodiment may exhibit advantageous characteristics during assembly and disassembly, as well as during operation, compared to some conventional designs, including relatively simplified assembly / disassembly operations due to the aforementioned structure. For example, during assembly or disassembly of the actuator 100, the connecting arm 156 can be moved into or out of the housing assembly 104 through one of the first or second passages 162, 164 while remaining threadedly secured to the piston rod 120. For example, during disassembly of the actuator 100, the cover 142 of the housing assembly 104 can be removed from the base 140. The pin installation tool 228 can be used to separate the slider pin 150 from the connecting arm 156. The piston inner end cap 128 can then be disconnected from the end cap 180 (and typically the housing base 140) and the cylinder assembly 102, with the connecting arm 156 still attached, allowing both the piston rod 120 and the connecting arm 156 to be removed from the yoke assembly 106, with the connecting arm 156 passing through the corresponding first or second passage 162, 164. A similar, but reverse, process can be used to assemble the actuator 100 .

[0095] As another example of the advantages of the illustrated design, the independent aspects of end caps 180, 182 can also help provide better performance and longevity. For example, because each end cap 180, 182 can be aligned and secured completely independently of each other end cap, the support axis of the associated component of the associated rod assembly 136 (e.g., piston rod 120 or one of the guide rods 154) can be independently adjusted. Consequently, optimal alignment of the opposing (or other) supports of each rod assembly 136 can be achieved relatively easily and reliably, without necessarily relying on tight machining tolerances of housing 104.

[0096] Figure 13The actuator 100 is shown assembled in accordance with one embodiment of the present invention (with the housing cover 142 removed for clarity). Generally speaking, as described above, the end caps 128, 180, 182 can be secured to the housing assembly 104 at either of the channels 162, 164, thereby allowing the actuator 100 to be assembled in two respective orientations without reorienting the housing base 140, providing either of two opposing rotational modes for the yoke assembly 106. For example, in Figure 13 In another orientation shown, one set of end caps 128, 180 and the corresponding cylinder assembly 102 can be moved from the first passage 162 of one of the first pair of opposing side walls 160 to the second passage 164. Correspondingly, the other of the set of end caps 128, 180 and the corresponding cylinder assembly 102 can be moved from the second passage 164 to the first passage 162 of the other of the first pair of opposing side walls 160. Likewise, the end caps 182 can be easily repositioned in a corresponding manner to provide opposite-side support for the associated rod assembly 136.

[0097] In some embodiments, different configurations of components can be used to secure the cylinder assembly to the housing assembly. For example, some embodiments can include a housing base having a single, large opening on each of two opposing sides thereof and a set of two corresponding end caps. Each end cap can be configured to simultaneously support the piston rod of the first rod assembly and the guide rod of the second rod assembly, such that the two end caps collectively provide contralateral support for the two rod assemblies of the actuator.

[0098] In this regard, for example, Figure 14 An actuator 300 according to another embodiment of the present invention is shown. Generally speaking, the actuator 300 can be used with valves similar to the actuator 100 described above and can operate similarly to the actuator 100. In particular, similar to the actuator 100, the actuator 300 includes a cylinder assembly 302, a housing assembly 304, and a yoke assembly 306. Various components of the actuator 300, including the yoke assembly 306, are substantially similar to corresponding components of the actuator 100 and, therefore, will not be described in particular detail. The discussion of the corresponding components of the actuator 100 also generally applies to the actuator 300. For example, the actuator 300 also includes a pair of rod assemblies 310 that are generally similar (e.g., substantially identical) to the rod assembly 136 of the actuator 100. The discussion of the rod assembly 136 generally applies to the rod assembly 310.

[0099] However, actuator 300 differs from actuator 100 in certain respects. Like rod assembly 136, rod assemblies 310 each include a respective piston rod 314 that is part of a respective cylinder assembly 302. However, in contrast to cylinder assembly 102, each of cylinder assemblies 302 is configured to engage with a single end cap 318 such that piston rod 314 extends through a first opening 320 defined by end cap 318. Furthermore, end cap 318 further defines a second opening 322 sized to receive and support a guide rod 328 of a different one of rod assemblies 310 therein, the guide rod being engaged with the cylinder assembly 302 secured to the respective end cap 318. In the illustrated embodiment, a guide rod shield 330 may also be secured to end cap 318 proximate second opening 322 to receive guide rod 328 therein. When the actuator 300 is fully assembled, each end cap 318 is secured to an opposite side of the housing assembly 304 to respectively support the corresponding cylinder assembly 302 with the yoke assembly 306 and the opposite guide rod 328 and the cylinder assembly 302 to support the guide rod 328.

[0100] Continuing, each cylinder assembly 302 includes a cylinder end cap 324 and a cylinder inspection cover 326 secured to the cylinder end cap 324. During assembly or disassembly of the actuator 300, the cylinder inspection cover 326 can be removed from the cylinder assembly 302 to access the piston rod 314. The piston rod 314 can then be screwed onto or unscrewed from the connecting arm 366 to secure or remove the cylinder assembly 302 relative to the housing assembly 304. In addition, in order to remove the cylinder assembly 302 relative to the housing assembly 304, the end cap 318 can be disconnected from the housing 338, as shown. Figure 14 shown.

[0101] Figure 15 The housing assembly 304 and the yoke 334 of the yoke assembly 306 are shown, configured to be at least partially enclosed by the housing assembly 304. In particular, the housing assembly 304 includes a housing 338 having openings 340 on opposite sides 342. Each end cap 318 is configured to engage with the housing 338 adjacent to a respective opening 340 and generally support each rod assembly 310. Similar to the actuator 100, each end cap 318 is configured to engage with either of the opposite sides 342 of the housing 338 to provide two orientations of the housing assembly 304, thereby providing either of two opposite rotational modes for the yoke assembly 306. However, while the rotational mode of the actuator 100 can be changed without necessarily removing the end caps 180, 182 (see FIG. 1 ), the end caps 180, 182 can be used to adjust the rotational mode of the actuator 100. Figure 11 ), but changing the rotational mode of the actuator 300 may require removing the end cap 318.

[0102] In this regard, for example, Figure 16The actuator 300 and housing assembly 304 are shown in a first orientation in a first rotational mode. To achieve a different orientation and a different rotational mode, each end cap 318, including its respective cylinder assembly 302 and the protective cover 330 secured thereto, can be removed from each opposite side 342 of the housing 338, rotated 180 degrees, and then secured to the original side 342 of the housing 338. The rod assembly 310 can then be reassembled and secured to the yoke assembly 306 (e.g., as described above), and operation in a different rotational mode can be performed without removing the yoke 334 from the associated valve (not shown) or removing and rotating the housing housing 338.

[0103] Figure 17 Shown Figure 16 A cross-section of the actuator 300 is shown, with the yoke assembly shown in the figure oriented corresponding to a 0 degree rotational orientation. Similar to the actuator 100, the actuator 300 is configured to operate between a 0 degree rotational orientation and a 90 degree rotational orientation. For example, Figure 18A -C shows a different orientation of the yoke assembly 304 and the rod assembly 310 within the housing 338. In particular, Figure 18A A 0 degree rotational orientation is shown, wherein the sliding member 348 is telescoped outwardly from the aperture 352 of the yoke 334 . Figure 18B A 45 degree rotated orientation is shown, wherein the sliding member 348 is telescoped inwardly into the aperture 352 of the yoke 334 . Figure 18C A 90-degree rotational orientation is shown, wherein the sliding member 348 is again telescoped outward from the hole 352 of the yoke 334. Each of the 0-degree and 90-degree rotational orientations corresponds to the maximum diagonal length required for the yoke assembly 306 and the rod assembly 310 within the housing assembly 304. Furthermore, compared to conventional designs—similar to actuator 100—the length of the yoke assembly 306 is minimized at the 45-degree rotational orientation. Accordingly, the overall dimensions of the housing assembly 304 can be significantly smaller than those required by conventional designs.

[0104] In some embodiments, a sliding support can be used for a rod assembly, including reducing the potential torque of an associated actuator on the rod assembly at a particular rotational orientation. In this regard, for example, Figure 19A -C shows a detailed view of the piston rod 314 within the cylinder assembly 302. In the illustrated embodiment, the cylinder assembly 302 also includes a sliding bushing 358 that slidably moves within the internal piston end cap 360 and slidably supports the piston rod 314. To facilitate the desired movement of the sliding bushing 358, the piston rod 314 is configured as a stepped rod and includes a shoulder 362 that contacts the sliding bushing 358 after the piston rod 314 has made a predetermined movement in a first direction (e.g., to open an associated valve). The shoulder 362 can then force the sliding bushing 358 to move with the rod 314 in the first direction (i.e., by sliding the bushing 358 from the FIG. 19B to FIG. 19CDuring the return movement of piston rod 314, sliding bushing 358 can be moved in the second direction by other mechanisms, such as by connecting arm 366 of rod assembly 310 to sliding bushing 368. Thus, sliding bushing 358, or other similar movable sliding bushings, can reduce any lateral forces acting on piston rod 314 from within housing assembly 304 as piston rod 314 advances. Similar features can also be applied to other embodiments, including with respect to actuator 100 discussed above.

[0105] As described above, some embodiments also include differently configured components to actuate the valve, including differently configured structures for engaging the sliding member with the yoke. For example, some embodiments may include a yoke assembly having a closed-end slot to engage a pin of a sliding member that may be pinned to a rod assembly. In this regard, for example Figure 20 and 21 A yoke assembly 400 is shown according to another embodiment of the present invention. Generally speaking, the yoke assembly 400 can be used with various Scotch yoke actuators, such as the actuators 100 and 300. Similar to the yoke assembly 106, the yoke assembly 400 includes a yoke 402, a valve engaging portion 404, a rod securing portion 406, and a sliding member 408. Similarly, the rod securing portion 406 defines a channel 412, the opposite end 414 of which is sized to slidably receive the sliding member 408 (see FIG. 1 ). Figure 20 ). Thus, as discussed above, the sliding member 408 can telescopically move with the yoke 402 to transmit torque to the yoke 402.

[0106] However, in contrast to the exemplary yokes illustrated in the previous figures, the rod securing portion 406 includes a plurality of slots 416, each of which extends between two opposing ends 414 of the channel 412. In particular, the slots 416 are configured as closed-end slots, extending continuously between the opposing ends of the channel 412, although other configurations are possible. Similarly, in contrast to the sliding members illustrated in the previous figures, as shown in FIG. Figure 22 As shown, the sliding member 408 includes a sliding body 420 and a bearing component 422 extending therefrom. In particular, the bearing components are configured as two solid pins that extend completely through the sliding body 420, although other configurations are possible.

[0107] In some embodiments, the slot 416 and the bearing component 422 can help provide better stress distribution during the engagement of the sliding member 408 with the yoke 402. Figure 23As shown, the bearing component 422 at one end of the sliding member 408 is configured to extend through the slot 416 when the sliding body 420 is received in the channel 412, while the bearing component 422 at the other end of the sliding member is configured to pivotally secure the sliding member 408 to the associated rod assembly. Therefore, when the sliding body 420 is telescopically slidable in the channel 412, the bearing component 422 can slide in the slot 416 under the drive of the rod assembly. Accordingly, the bearing component 422 in the slot 416 can help provide a more favorable stress distribution in the yoke 402 and the sliding member 408 during operation. In general, configurations having a slotted yoke channel, including those with Figure 20-23 Configurations similar to the one shown may be used with various actuators, including the actuators 100 , 300 discussed above.

[0108] Figure 24-3 0 illustrates other configurations of yoke assemblies according to some embodiments of the present invention. Generally speaking, each of the yoke assemblies 400 described above and the various yoke assemblies described below are suitable for use with various actuators, including, for example, actuators 100 and 300. Furthermore, the operation of each of the following yoke assemblies is substantially similar to that of yoke assembly 106 of actuator 100. Therefore, the operational details of yoke assembly 106 described above are generally applicable to the following yoke assemblies.

[0109] Figure 24 A yoke assembly 450 is shown, comprising a yoke 452 and sliding members 454 that are telescopically slidable within a bore of the yoke 452. Each sliding member 454 includes opposing free ends, one of which extends telescopically into the yoke 452 and the other of which is configured to rotatably engage a connecting arm 456 of a lever assembly. In the illustrated embodiment, the connecting arm 456 of the lever assembly is configured as a U-shaped clip that can be pivotally connected to the sliding member 454 via a sliding pin.

[0110] Figure 25 A yoke assembly 470 is shown, comprising a yoke 472 and a set of sliding members 474, each of which is slidable within one of a set of respective apertures 476. In the illustrated embodiment, each aperture 476 defines a bore axis. Each bore axis is substantially parallel to the other, but extends in a separate plane. Thus, each sliding member 474 is able to slide along the entire length of its respective aperture 476 (or a substantial portion, e.g., more than halfway) without contacting other sliding members 474. Similar to the yoke assembly 450, each sliding member 474 includes a free end that is configured to pivotally engage a connecting arm 478 of a lever assembly.

[0111] Figure 26A yoke assembly 500 is shown, comprising a yoke 502 and a set of sliding members 504, 506. The first sliding member 504 includes a channel 508 sized to receive the second sliding member 506, and the yoke 502 includes a hole 510 sized to receive the first sliding member 504. Thus, the first sliding member 504 is configured to slide telescopically within the hole 510, and the second sliding member 506 is configured to slide telescopically within the channel 508 of the first sliding member 504. Each sliding member 504, 506 includes a free end configured to pivotally engage a connecting arm 512 of the lever assembly.

[0112] Figure 27 A yoke assembly 520 is shown, comprising a yoke 522 and a pair of sliding members 524. The yoke 522 includes a bore 526 sized to receive a pair of bushings 528, each bushing 528 being configured to slidably receive a respective sliding member 524 for telescopic movement. Each sliding member 524 includes opposing free ends, one of which is configured to pivotally engage a connecting arm 530 of a lever assembly. In the illustrated embodiment, the bore 526 is part of an internal passage 532 extending through the yoke 522, although similar bushings may be used for other passages having different configurations.

[0113] Figure 28 A yoke assembly 540 is shown, comprising a yoke 542 and a set of sliding members 544 extending into respective sets of apertures 546 formed in the yoke 542. The apertures 546 extend completely through the yoke 542 along aperture axes that are parallel to, but vertically offset from, the axis defined by the yoke 542. Similarly, the sliding members 544 extend parallel to, but vertically offset from, the axis defined by the yoke 542. Each sliding member 544 includes a first free end 548 and a second free end 550, with each free end 548 being configured to pivotally engage a corresponding connecting arm 552 of the lever assembly and each second free end 550 being configured to telescopically slide within a corresponding one of the apertures 546.

[0114] Figure 29 A yoke assembly 560 is shown, including a yoke 562 having a first valve engaging portion 564 and a second rod securing portion 566. The first yoke portion 564 is configured to engage the valve portion of the actuator. The second yoke portion 566 is secured to the first yoke portion 564 by a plurality of pins 568 while maintaining sufficient separation from the first yoke portion 564 to define a passage 570 therebetween. The yoke assembly 560 also includes a pair of sliders 572. Each slider 572 includes a first free end that can slide over a portion of the other slider 572 within the passage 570. Each slider 572 also includes a second free end that is configured to pivotally engage a connecting arm 574 of the rod assembly.

[0115] Figure 29This configuration can be particularly advantageous, for example, in reducing wear on associated components while avoiding material limitations that may exist with certain manufacturing methods. For example, the first and second yokes 564 and 566 can be relatively inexpensively cast from conventional materials, while the pin 568 can be formed from a different, non-cast material that exhibits relatively high strength and durability. Thus, in addition to securing the first and second yokes 564 and 566 together, the pin 568 can serve as a high-strength bearing component along which the slider 572 can slide, transferring torque to the yoke 562 as a whole.

[0116] In some embodiments, the rod assembly can be fixed to the sliding member so that the sliding member can move with two degrees of freedom relative to the rod assembly (e.g., rotation and translation). In this regard, for example, Figure 30A Figure 5-C shows a yoke assembly 580 within a housing 582. The yoke assembly 580 includes a yoke 584 and a pair of sliding members 586 that extend telescopically into a hole 588 formed in the yoke 584. Each sliding member 586 includes a first free end 590 that extends out of the hole 588, and each first free end 590 includes a slot 592 formed therein. Each sliding member 586 is configured to pivotally engage a connecting arm 594 of the lever assembly at the slot 592 via a slider pin 596 having a diameter that is less than the length of the slot 592. Accordingly, the slider pin 596 is configured to move along the length of the slot 592 when the lever assembly moves linearly and the yoke 584 rotates about the yoke axis.

[0117] Figure 30A The yoke assembly 580 is shown in a 0 degree rotational orientation, with the slide members 586 each retracted a maximum distance from the aperture 588 and the slider pin 596 located at the distal end of the slot 592 . Figure 30B The yoke assembly 580 is shown in an intermediate rotational orientation (ie, between 0 and 45 degrees) wherein the slide members 586 are each telescopically retracted into the apertures 588 and the slider pins 596 remain positioned at the distal ends of the slots 592. In contrast, Figure 30C Yoke assembly 580 is shown in a 45-degree rotational orientation, with the slide members each retractable into aperture 588 at their maximum distance, and slider pin 596 located at the intermediate end of slot 592. Generally speaking, slot 592 can thus facilitate a compact design using housing 582 without affecting the torque capacity of yoke assembly 580, and can also, similar to the other pin and slot configurations discussed above, help provide favorable stress distribution during operation.

[0118] In some embodiments, methods embodying aspects of the present invention may be used to utilize, manufacture, or install the devices or systems disclosed herein. Accordingly, descriptions herein of specific features, capabilities, or intended purposes of a device or system are generally intended to essentially encompass the disclosure of methods for using such features for their intended purposes, methods for implementing such capabilities, methods for manufacturing the relevant components of such a device or system (or the device or system as a whole), and methods for installing the disclosed (or otherwise known) components to support these purposes or capabilities. Similarly, unless otherwise indicated or limited, any discussion herein of methods for manufacturing or using a specific device or system (including installing the device or system) is intended to essentially encompass the disclosure of the utilized features and implemented capabilities of such a device or system as an embodiment of the present invention.

[0119] In this regard, for example, Figure 31 A method 610 for rotating a Scotch yoke actuator for a torsion valve is shown. As an example, reference will now be made to the actuator 100 (see also FIG. Figure 1-13 ) describes the method 610, although other actuators may be used. Operation 612 of method 610 includes disconnecting the connecting arm 156 from the sliding member 148 within the housing assembly 104. Prior to disconnecting the connecting arm 156 from the sliding member 148, the sliding member 148 may be pivotally supported by the connecting arm 156 for telescopic movement within the aperture 196 of the yoke 146. Operation 614 of method 610 includes unscrewing the guide rod 154 from the connecting arm 156, which may be performed before or after disconnecting the connecting arm 156 from the sliding member 148.

[0120] Operation 616 of method 610 includes removing the connecting arm 156 from the housing assembly 104. For example, the connecting arm 156 can be removed from the base 140 of the housing assembly 104 through one of the first or second channels 162, 164 in one of the first pair of opposing sidewalls 160. Accordingly, the connecting arm 156, still secured to the piston rod 120, can be moved away from the housing assembly 104 by moving the cylinder assembly 102.

[0121] Operation 618 of method 610 includes inserting the connecting arm 156 into the other of the first or second channels 162, 164 on the same side of the first pair of opposing sidewalls 160 without flipping or reversing the orientation of the base 140. The cylinder assembly 102 can then be fixed relative to the housing assembly 104. Continuing, operation 620 of method 610 includes inserting the guide rod 154 into the first or second channel 162, 164 on the same side of one of the first pair of opposing sidewalls 160 without flipping or reversing the orientation of the base 140 (i.e., directly opposite the first or second channel 162, 164 into which the connecting arm 156 was inserted at operation 618), and screwing the guide rod 154 into the connecting arm 156. Operation 622 of method 610 includes connecting the connecting arm 156 to the other sliding member 148 within the base 140 of the housing assembly 104. In this regard, for example, embodiments of the present invention that do not require rotation of the housing assembly, but rather require removal of the yoke from the valve, may advantageously allow changing the rotational mode of the actuator without disconnecting the actuator from the associated valve.

[0122] As described above, other approaches are also possible. For example, in some cases, the rod assembly can be disconnected from the connecting arm, and the connecting arm can remain within the housing (e.g., still connected to the slide member) when the rod assembly is removed. The corresponding actuator can then be oriented as appropriate (e.g., as described above) and then reconnected, accordingly reconnecting the rod assembly to the same (or different) connecting arm.

[0123] Figure 32 A method 630 for removing a yoke of a Scotch yoke actuator for a valve is shown. As an example, the method 630 will be described below with reference to the actuator 100, although other actuators may be used. Operation 632 of the method 630 includes unscrewing the piston rod 120 from the connecting arm 156 while the connecting arm 156 is disposed within the base 140 of the housing assembly 104. Operation 634 of the method 630 includes unscrewing the guide rod 154 from the connecting arm 156. As described above, the guide rod can be disconnected from the connecting arm before or after the actuator rod. Furthermore, in some cases (such as when the guide rod is not used), it may not be necessary to remove the guide rod in this method and other methods disclosed herein.

[0124] Operation 636 of method 630 includes removing the cover 142 of the housing assembly 104 to provide access to the top opening of the base 140 without disassembling the cylinder assembly 102. Operation 638 of method 630 includes removing the yoke assembly 106 from the base 140 of the housing assembly 104. In this regard, for example, embodiments of the present invention may advantageously allow the yoke to be replaced while the actuator assembly remains in place, rather than requiring removal of the actuator assembly to replace the yoke.

[0125] Other variations are possible, consistent with the general principles discussed above and the structure and function presented with respect to the specific, illustrated embodiments. In some embodiments, aspects of some of the arrangements discussed or illustrated above may be interchanged with or added to aspects of other arrangements consistent with the general scope of the present disclosure. For example, any yoke assembly or component thereof disclosed herein may be used in an actuator similar to any of the actuators 100, 300 described above. Similarly, different configurations of known rod assemblies, linear actuators, limit stops, etc. may be substituted for corresponding components of any of the configurations discussed above, or otherwise added to the above configurations. Furthermore, methods 610 and 630 may be readily applied to various other actuators, including actuator 300, with or without corresponding changes to the described operations.

[0126] Thus, embodiments of the present invention can provide an improved actuator for a valve compared to conventional methods. For example, in some embodiments, the actuator can include a yoke assembly that produces a torque curve similar to conventional actuators while providing a compact and robust housing. Furthermore, embodiments disclosed herein can provide simplified assembly, disassembly, and reversal of the valve actuator.

[0127] Those skilled in the art will appreciate that although the present invention has been described above with reference to specific embodiments and examples, the present invention is not necessarily limited thereto, and many other embodiments, examples, uses, modifications and deviations from the embodiments, examples, uses are intended to be included in the appended claims. Various features and advantages of the present invention are set forth in the appended claims. Various features and advantages of the present invention are set forth in the following claims.

Claims

1. An actuator for a valve assembly, the actuator comprising: a yoke having at least one aperture, the yoke being configured to rotate about a yoke axis to actuate the valve assembly, and the at least one aperture extending transverse to the yoke axis; a first rod assembly configured to move in a first direction transverse to the at least one aperture and the yoke axis, the first rod assembly comprising a piston rod, a guide rod, and a first connecting arm threadedly coupled to the guide rod and the piston rod; as well as A first sliding member is located in the at least one hole and is pivotally fixed to the first connecting arm of the first rod assembly. The first sliding member is configured to slide telescopically in the at least one hole when the first rod assembly moves along the first direction to transmit torque to the yoke for driving the valve assembly.

2. The actuator of claim 1 , wherein the first sliding member includes a first free end pivotally secured to the first rod assembly and a second free end telescopically nested within the at least one hole, and wherein the first free end of the first sliding member is pivotally secured to the first rod assembly by being pivotally connected to the first connecting arm.

3. The actuator according to claim 1, wherein The first rod assembly includes a piston rod of a cylinder assembly, the piston rod being configured to controllably move the first rod assembly in the first direction.

4. The actuator according to claim 3, wherein the piston rod is slidably supported by a sliding bushing, and wherein the piston rod is a stepped rod having a shoulder, which contacts the sliding bushing after a predetermined movement along the first direction, causing the sliding bushing to slide in the first direction.

5. The actuator according to any one of claims 1 to 4, further comprising: a housing at least partially surrounding the yoke, the first lever assembly, and the first sliding member; The first lever assembly extends across the housing transverse to the yoke axis and is slidably supported on opposite sides of the housing for movement in the first direction.

6. The actuator of claim 5, wherein the housing comprises a housing shell, the housing shell including openings on each of opposing sides, a first end cap, and a second end cap; in, The first end cap and the second end cap are fixed to the housing case at corresponding ones of the openings and slidably support the first rod assembly.

7. The actuator of claim 6, wherein the first end cap supports a linear actuator relative to the housing for movement of the first rod assembly in the first direction; and in, The first end cap is configured to be secured to the housing in either of two orientations to provide either of two opposing rotational modes for the yoke.

8. The actuator according to claim 6, wherein: The first rod assembly comprises: a piston rod extending through the first opposite side of the housing; a connecting arm threadably fixed to the piston rod and pinned to the first sliding member; and A guide rod is threadably secured to the connecting arm opposite the piston rod and extends through a second opposite side of the housing, wherein the piston rod is slidably supported by the first end cap and the guide rod is slidably supported by the second end cap.

9. The actuator according to claim 1, further comprising: a limiting sleeve threadably engaged with a housing of the actuator; wherein the first rod assembly extends through the limiting sleeve; and The limiting sleeve can be adjusted relative to the housing in a threaded manner to adjust the position of the limiting baffle of the first rod assembly relative to the movement of the first rod assembly in the first direction.

10. The actuator according to claim 9, wherein The first side of the limiting sleeve is configured to contact the first portion of the first rod assembly to provide a first limiting stop, and the second side of the limiting sleeve is configured to contact the second portion of the first rod assembly to provide a second limiting stop.

11. The actuator according to claim 1 , further comprising: a second rod assembly configured to move in a second direction transverse to the at least one aperture and the yoke axis, opposite the yoke of the first rod assembly; as well as A second sliding member is located in the at least one hole and is pivotally fixed to the second rod assembly, and the second sliding member is configured to slide telescopically in the at least one hole when the second rod assembly moves in the second direction to transmit torque to the yoke, thereby driving the valve assembly.

12. The actuator of claim 1 , wherein the at least one aperture comprises a slot; and in, A pin extends from the first slide member to slidably engage the slot.

13. A yoke for an actuator of a valve assembly, the yoke comprising: a valve engaging portion configured to engage with a valve member to rotate the valve member via the actuator; as well as a stem fixing portion formed separately from the valve engaging portion; wherein the stem securing portion is secured to the valve engaging portion so as to define a passage therebetween, such that the bearing member extends between the stem securing portion and the valve engaging portion on first and second opposing sides of the passage; and wherein the channel is sized to receive one or more sliding members through at least one of the third or fourth opposite sides of the channel, the sliding members being pivotally fixed to one or more rod assemblies of the actuator such that sliding motion of the one or more rod assemblies is converted into torque on the yoke through sliding motion of the one or more sliding members along the bearing component within the channel.

14. The yoke according to claim 13, wherein The channel is sized to receive two slide members for opposite, parallel and overlapping movement.

15. A method of reversing a rotational mode of a Scotch yoke actuator for a valve, the method comprising: disconnecting a connecting arm from a first sliding member, the connecting arm being disposed within a housing of the actuator and, prior to disconnection, pivotally secured to and pivotally supporting the first sliding member so that the first sliding member can perform telescopic movement within a corresponding aperture of a yoke of the actuator; removing the connecting arm and linear actuator from a first side of the housing proximate a first inlet of the housing for applying torque to the yoke via an actuator rod and the connecting arm; inserting the connecting arm into a second inlet of the housing at a first side of the housing without reversing the orientation of the housing, and securing the linear actuator to the housing adjacent the second inlet; and The connecting arm is connected to a second sliding member in the housing so that the second sliding member can perform telescopic movement in the yoke.

16. A method of removing a yoke from a Scotch yoke actuator for a valve, the method comprising: unscrewing an actuator rod of the linear actuator from engagement with a connecting arm disposed within a housing of the actuator and pivotally supporting a sliding member so that the sliding member performs telescopic movement within a corresponding aperture of the yoke; removing a top cover of the housing to provide a top opening in the housing without removing the linear actuator from the housing or removing side walls of the housing that support the actuator and the actuator rod during operation; and The yoke is removed through the top opening.

17. An actuator for a valve assembly, the actuator comprising: a yoke having a passage, the yoke being configured to rotate about a yoke axis to actuate the valve assembly, and the passage extending from a peripheral edge of the yoke toward the yoke axis; a rod assembly configured to move in a first direction transverse to the channel and the yoke axis, the rod assembly comprising a piston rod, a guide rod, and a connecting arm coupled to the guide rod and the piston rod; and a sliding member pivotally secured to the connecting arm at a first end and extending from the first end toward the yoke shaft to a second end of the sliding member, the second end being opposite the first end and slidingly engaged with the channel; in, Movement of the rod assembly in a first direction causes the sliding member to pivot relative to the rod assembly at the first end and slide within the channel at the second end, thereby providing a torque on the yoke.

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