Gearbox for a valve, a worm gear assembly, a worm wheel, a sleeve, a method to manufacturate a worm gear assembly

Abstract

Gearboxes with insertable sleeves for valve connections are described herein. An example gearbox includes a housing and a gear in the housing. The gear has a central opening defined by an inner surface of the gear. The inner surface has a first portion of a threaded fastener bore. The gearbox also includes a sleeve in the central opening of the gear. The sleeve has a first axial end, a second axial end, and an outer side surface between the first and second axial ends. The sleeve defines a keyed opening to receive a stem or shaft of the valve. The outer side surface of the sleeve has a second portion of the threaded fastener bore. The first portion and the second portion are aligned to form the threaded fastener bore. The gearbox further includes a threaded fastener screwed into the threaded fastener bore to couple the gear and the sleeve.

Description

GEARBOX FOR A VALVE, A WORM GEAR ASSEMBLY, A WORM WHEEL, A SLEEVE, A METHOD TO MANUFACTURATE A WORM GEAR ASSEMBLYFIELD OF THE DISCLOSURE

[0001] This disclosure relates generally to gearboxes and, more particularly, to gearboxes with insertable sleeves for valve connections.BACKGROUND

[0002] Actuators automate control valves by providing a force and / or torque that causes motion and / or rotation to open or close a valve. In operation, a controller may cause an actuator to position a flow control member of a valve to a desired position to regulate fluid flowing through the valve. Actuators often include and / or are connected to a valve via a gearbox or gear assembly. The gearbox can provide a specific gear ratio between the actuator and the valve as well as change the direction of the actuation motion (e.g., from vertical to honzontal).SUMMARY

[0003] An example gearbox for a valve disclosed herein includes a housing and a gear in the housing. The gear has a central opening defined by an inner surface of the gear. The inner surface has a first portion of a threaded fastener bore. The gearbox also includes a sleeve in the central opening of the gear. The sleeve has a first axial end, a second axial end, and an outer side surface between the first and second axial ends. The sleeve defines a keyedopening to receive a stem or shaft of the valve. The outer side surface of the sleeve has a second portion of the threaded fastener bore. The first portion and the second portion are aligned to form the threaded fastener bore. The gearbox further includes a threaded fastener screwed into the threaded fastener bore to couple the gear and the sleeve.

[0004] An example worm gear assembly disclosed herein includes a worm and a worm wheel including a hub and a disc portion with teeth. The disc portion extends radially from the hub. The hub defines a central opening. The worm gear assembly includes a sleeve in the central opening. The worm wheel and the sleeve form a threaded fastener bore partially formed on an inner surface of the worm wheel and partially formed on an outer side surface of the sleeve. The worm gear assembly also includes a threaded fastener screwed into the threaded fastener bore to couple the worm wheel and the sleeve.

[0005] An example worm wheel of a worm gear assembly disclosed herein includes a disc portion with teeth. The worm wheel also includes a hub. The disc portion extends radially from the hub. The hub defines a central opening. An inner surface of the central opening has a portion of a threaded bore.

[0006] An example sleeve disclosed herein is to be inserted into a central opening of a gear to interface with a stem or shaft of a valve. The sleeve includes a first axial end, a second axial end opposite ethe first axial end, and an outer side surface between the first axial end and the second axial end. The outer side surface has a portion of a threaded bore fastener.

[0007] An example method disclosed herein includes drilling a central opening in a hub of a worm wheel, forming a first portion of a threaded fastener bore on an inner surface of the hub that forms the central opening, and inserting a sleeve into the central opening. The sleeve has a second portion of the threaded fastener bore. The sleeve is inserted into the central opening such that the second portion aligns with the first portion to form the threaded fastener bore.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a perspective view of an example gearbox used in connection with an example valve.

[0009] FIG. 2 shows an example worm gear assembly including an example worm and an example worm wheel that can be implemented in the example gearbox of FIG. 1.

[0010] FIG. 3 is a partially exploded view of the example gearbox and the example valve of FIG. 1 showing an example sleeve of the example gearbox that is used to interface with an example valve stem of the example valve.

[0011] FIG. 4 is a top view of the example gearbox and the example valve of FIG. 1.

[0012] FIG. 5 is a cross-sectional view of the example gearbox and the example valve of FIG. 1.

[0013] FIG. 6 is an assembled view of the example worm wheel and the example sleeve of the example gearbox of FIG. 1.

[0014] FIG. 7 is an exploded view of the example worm wheel and the example sleeve of FIG. 6.

[0015] FIGS. 8A-8D show four example orientations of the example sleeve in the example worm wheel of FIG. 6.

[0016] FIGS. 9A and 9B show other example sleeves used in the example worm wheel of FIG. 6.

[0017] FIG. 10 shows an example blank sleeve with a pilot bore.

[0018] FIGS. 11A-11C show an example process of retrofitting an existing worm wheel to receive an example sleeve.

[0019] FIG. 12 is a flowchart representative of an example method of retrofitting an existing worm wheel with an example sleeve.

[0020] The figures are not necessarily to scale. Instead, the thickness of the layers or regions may be enlarged in the drawings. In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts.DETAILED DESCRIPTION

[0021] Actuators are commonly used in process control systems to automate control of certain devices or components of the process control system. For example, actuators are commonly used to automate control valves by providing a force and / or torque that may cause linear and / or rotary motion to open or close a valve. In many instances, a gearbox is connected between the actuator and the valve. The gearbox includes a gear assembly that provides a specific gear ratio to achieve a desired change in speed and / ortorque between an input shaft of the gearbox and a stem / shaft of the valve.For example, the gearbox may include a specific gear arrangement to reduce speed while increasing torque, which enables a relatively small actuator to control or operate a larger valve.

[0022] Some gearboxes include a worm gear assembly, which includes a worm and worm wheel (e.g., a spur gear). The worm wheel has a hub with a keyed opening. The stem or shaft of the valve has a specific key shape and is inserted into the keyed opening of the worm wheel. As such, the worm wheel and the valve stem / shaft are keyed together, which enables the worm wheel to transfer rotational motion and torque to the valve stem / shaft.

[0023] However, many different ty pes of valves and valve stems / shafts exist. Therefore, gearbox manufacturers have to manufacture numerous versions of the worm wheel with differently shaped keyed openings to fit the various types of valves and valve stems / shafts. As such, each gearbox is custom made with a worm wheel having a specific keyed opening. This is costly and cumbersome. This arrangement is also complicated when a worm wheel needs to be changed or customized last minute to fit a customer’s unique valve stem / shaft shape.

[0024] Disclosed herein are example gearboxes that include a gear, such as a worm wheel, with a central opening and a drive sleeve that is disposed in the central opening and coupled to the worm wheel. The sleeve has a keyed opening to receive a valve stem / shaft, thereby forming an interface between the worm wheel and the valve stem / shaft. The sleeve is coupled to the worm wheel to enable the sleeve to be easily removed andinterchanged with a different sleeve having a differently shaped keyed opening. As such, the same worm wheel can be outfitted with different sleeves to interface with different valve stems. This enables a gearbox manufacturer to produce one type of gearbox that can be easily adapted to work with different types of valve and valve stems / shafts. Further, the sleeve can also be easily adjusted to change orientation in the worm wheel, which enables the gearbox and the valve to be connected in various orientations.

[0025] FIG. 1 illustrates an example gearbox 100 constructed in accordance with the teachings of this disclosure. The gearbox 100 may also be referred to as a transmission or geartrain. In FIG. 1, the gearbox 100 is shown in connection with an example valve 102. The gearbox 100 has internal gears, as disclosed in further detail herein, that transfer rotational motion and / or power to operate (e.g., open or close) the valve 102. In this example, the valve 102 is a butterfly valve. However, the example gearbox 100 can also be used in connection with other types of valves (e.g., ball valves, rotary sleeve valves, etc.). In the illustrated example, the valve 102 has a valve body 104 defining a flow passage 106 and a disc 108 disposed in the flow passage 106 of the valve body 104. The valve body 104 can be coupled between upstream and dow nstream pipes to control the flow of a fluid between the pipes. The disc 108 is rotatable in the valve body 104 between a closed position, which is shown in FIG. 1, and an open position. In the closed position, the disc 108 blocks the flow passage 106, thereby preventing fluid flow between the pipes. The disc 108 can be rotated to an open position, in which the disc 108 is at least partially angled relative to the valve body 104,which allows fluid to flow through the flow passage 106 and, thus, between the pipes. The valve 102 includes a valve stem 110 (which may also be referred to as a valve shaft or rod) that is coupled to the disc 108. The valve stem 110 can be rotated to rotate the disc 108 between the open and closed positions. In some examples, the disc 108 is rotatable about 90° between the fully closed position, shown in FIG. 1, and a fully open position in which the disc 108 is substantially perpendicular to the flow passage 106. The disc 108 can also be rotated to any position or angle between the fully closed position and the fully open position.

[0026] In the illustrated example, the gearbox 100 is coupled to the valve 102. In this example, the valve 102 has a shaft 1 12 with a flange 1 14 extending from the valve body 104, and the gearbox 100 is coupled to the flange 114. For example, the gearbox 100 may be coupled to the flange 114 via one or more threaded fasteners (e.g., bolts). The valve stem 110 extends through the shaft 112 and the flange 114 into the gearbox 100.

[0027] In the illustrated example, the gearbox 100 includes a housing 116, which may be formed by one or more walls or plates. The gearbox 100 includes an internal gear assembly (formed by one or more gears) in the housing 116. The internal gear assembly transfers rotational motion and power to the valve stem 110. For example, the gearbox 100 includes a gear 118 (only a portion of which is visible in FIG. 1). The gear 118 has a central opening 120. The valve stem 110 extends into the central opening 120 and is coupled to the gear 118. In the illustrated example, the gearbox 100 has an input shaft 122. The input shaft 122 is operatively coupled to (e.g., in gearwith) the gear 118. Therefore, rotation of the input shaft 122 causes rotation of the gear 118, which causes rotation of the valve stem 110 and the disc 108.In some examples, an actuator 124, such as an electric motor, can be coupled to the input shaft 122. The actuator 124 can be activated to rotate the input shaft 122, which, via the internal gears of the gearbox 100, causes rotation of the valve stem 110. In other examples, a handwheel can be coupled to the input shaft 122 to enable a person to manually operate the valve 102. The internal gear assembly of the gearbox 100 can provide a certain gear ratio between the input shaft 122 and the valve stem 110. This can be used to increase torque as well as provide accurate position control of the disc 108. Further, the gearbox 100 can be used as an interface to change the direction of rotational motion and / or power. For example, in FIG. 1, the input shaft 122 and the valve stem 110 are perpendicular to and offset from each other. Therefore, the gearbox 100 can transfer rotational motion between two shafts that are not aligned (e.g., not coaxial).

[0028] In the illustrated example, the gearbox 100 includes a sleeve 126, which may also be referred to as a drive sleeve or insert. The sleeve 126 forms an interface between the valve stem 110 and the gear 118 of the gearbox 100. The sleeve 126 is disposed in the central opening 120 of the gear 118 and coupled to the gear 118. The sleeve 126 has a keyed opening 128 to receive the valve stem 110. The keyed opening 128 has a shape that matches a specific key feature or shape on the valve stem 110. The keyed opening 128 can also be referred to as keyway. The sleeve 126 can be customized based on the shape of the key feature and / or interchanged with other sleeves havingdifferently shaped keyed openings. This enables the gearbox 100 to be easily adapted to different valves having different types and / or shapes of valve stems.

[0029] In this example, the gearbox 100 includes a worm gear assembly or drive. Worm gear assemblies provide high gear reduction ratios, which result in high torque output. Worm gear assemblies also have limited or reduced backdrive. Therefore, worm gear assemblies are advantageous for use in applications where high torque and / or limited backdrive are desired. FIG. 2 shows an example worm gear assembly 200 of the example gearbox 100. The worm gear assembly 200 includes a worm 202 and the gear 118, which is implemented as a worm wheel and referred to herein as the worm wheel 1 18. The worm 202 is coupled to and / or otherwise forms part of the input shaft 122 (FIG. 1). As such, rotation of the input shaft 122 causes rotation of the worm 202. The worm 202 has a shaft with a spiral tooth (e.g., a screw) that is engaged or meshed with the teeth on the worm wheel 118. When the gearbox 100 (FIG. 1) is assembled with the valve 102 (FIG. 1), the valve stem 110 (FIG. 1) is coupled to the worm wheel 118. Therefore, rotation of the worm 202 causes rotation of the worm wheel 118, which causes rotation of the valve stem 110. Depending on the size and number of teeth of the worm wheel 118 and the worm 202, this arrangement can provide a relatively high gear reduction ratio, which results in high torque multiplication. This worm gear arrangement also reduces (e.g., minimizes) backdrive. The worm 202 and the worm wheel 118 can be constructed of any material, such as metal (e.g., aluminum, steel, iron, etc.).

[0030] In the illustrated example, the worm wheel 118 has a hub 204(which may also be referred to as a shaft portion) and a disc portion 206 with teeth coupled to the hub 204. The disc portion 206 extends radially outward from the hub 204. In the illustrated example, the hub 204 defines or forms the central opening 120. When the gearbox 100 (FIG. 1) is assembled with the valve 102 (FIG. 1), the valve stem 110 (FIG. 1) extends into the central opening 120 and is coupled to the hub 204 via the sleeve 126, as disclosed in further detail herein. In this example, the disc portion 206 is only a quarter of a complete circle because the disc 108 (FIG. 1) of the valve 102 is only rotatable a quarter turn between the fully open position and the fully closed position. However, in other examples, the disc portion 206 can extend further around the hub 204 (e g., 180°, 360°) to enable the worm wheel 11 and the valve stem 110 to be rotated through other angles. In some examples, the hub 204 and the disc portion 206 are constructed as a unitary part or component (e.g., a monolithic structure). In other examples, the hub 204 and the disc portion 206 can be constructed as separate parts or components that are coupled together (e.g., via welding, via fasteners, etc.).

[0031] As shown in FIG. 2, the sleeve 126 is disposed in the central opening 120 of the worm wheel 118. The sleeve 126 is coupled to the worm wheel 118. In this example, the sleeve 126 is coupled to the worm wheel via a plurality of threaded fasteners 208, such as bolts. The threaded fasteners 208 extend axially into threaded fastener bores (which may be partially or fully threaded) formed at the joint between the hub 204 and the sleeve 126, as disclosed in further detail herein. This coupling ensures the sleeve 126 isrotationally fixed relative to the worm wheel 118. As such, the worm wheel 118 and the sleeve 126 rotate together as a unit. As stated above, the sleeve 126 forms an interface between the worm wheel 118 and the valve stem 110. The sleeve 126 rotationally fixes or constrains the worm wheel 118 and the valve stem 110. Therefore, rotation of the worm wheel 118 causes rotation of the valve stem 110. In some examples, the sleeve 126 is constructed of carbon steel, which provides excellent load transfer. In other examples, the sleeve 126 can be constructed from other types of materials. In the illustrated example, the sleeve 126 has the keyed opening 128 to receive the valve stem 110. The keyed opening 128 can be customized and / or otherwise selected based on the specific key shape on the valve stem 1 10. This enables the gearbox 100 to be usable with different types of valves having different key shapes.

[0032] FIG. 3 is a partially exploded view of the gearbox 100 and the valve 102. As shown in FIG. 3, the valve stem 110 extends upward from the flange 114. The valve stem 110 has a key feature 300 near an end 302 of the valve stem 110. In this example the key feature 300 is a rectangular protrusion on one side of the valve stem 110. The keyed opening 128 of the sleeve 126 has a shape that compliments or matches the valve stem 110. For example, as shown in FIG. 3, the keyed opening 128 has a notched portion 304 to receive the key feature 300. As such, when the valve stem 110 is disposed in the keyed opening 128 of the sleeve 126, the sleeve 126 and the valve stem 110 are rotationally fixed or constrained.

[0033] As mentioned above, the sleeve 126 is coupled to the worm wheel 118 via the threaded fasteners 208a-208d. The threaded fasteners 208a- 208d are screwed or threaded into threaded fastener bores. Each of the threaded fastener bores is partially formed by the worm wheel 118 and partially formed by the sleeve 126, as disclosed in further detail herein. In some examples, the gearbox 100 includes spring washers 306 (one of which is referenced in FIG. 3) around each of the threaded fasteners 208a-208d to provide tension and / or preload. In other examples, spring washers may not be used.

[0034] FIG. 4 is a top view of the gearbox 100 and the valve 102. As shown, the valve stem 1 10 is disposed in the keyed opening 128 of the sleeve 126 with the key feature 300 in the notch 304. Therefore, the valve stem 1 10 and the worm wheel 118 are rotationally constrained or locked. The sleeve 126 can be easily removed by removing the threaded fasteners 208a-208d (FIG. 3). Then, a different sleeve can be inserted into and coupled to the worm wheel 118.

[0035] FIG. 5 is a cross-sectional view of the gearbox 100 and the valve 102. The worm gear assembly 200, including the worm wheel 118 and the worm 202 (FIG. 2), is disposed in the housing 116. The valve stem 110 extends into the gearbox 100 and is disposed in the sleeve 126. In the illustrated example, the housing 116 of the gearbox 100 has a top plate 500 and a botom plate 502 that are coupled together (e.g., via one or more threaded fasteners). In other examples, the housing 116 can be formed by a number or arrangement of plates or walls. In the illustrated example, the topplate 500 has a first opening 504, and the bottom plate 502 has a second opening 506. The hub 204 of the worm wheel 118 has an upper portion 508 and a lower portion 510. The upper portion 508 is disposed in the first opening 504 in the top plate 500, and the lower portion 510 is disposed in the second opening 506 in the bottom plate 502. In some examples, the top and bottom portions 508, 510 are engaged with and rotate along the inner surfaces defining the first and second openings 504, 506. For example, the top and bottom portions 508, 510 and the inner surfaces of the first and second openings 504, 506 form journal bearings, which enables the worm wheel 118 to rotate smoothly in the housing 116. In some examples, a lubricant can be provided between the surfaces to reduce friction. Alternatively, in other examples, one or more bearings (e g., ball bearings) can be provided between the top and bottom portions 508, 510 and the inner surfaces of the first and second openings 504, 506.

[0036] As shown in FIGS. 4 and 5, a portion of the worm wheel 118 and the sleeve 126 extend upward from the first opening 504. As such, the sleeve 126 is accessible from the top of the gearbox 100. This enables a person to easily access the sleeve 126 so the person can insert the sleeve 126, adjust the sleeve 126, remove the sleeve 126, and / or interchange the sleeve 126 with another sleeve, without removing the worm wheel 118 from the housing 116.

[0037] FIG. 6 is a partial cross-sectioned perspective view of the worm wheel 118, the sleeve 126, and the threaded fasteners 208a-208d in an assembled state. The sleeve 126 is disposed in the central opening 120 of theworm wheel 118 and coupled to the worm wheel 118 via the threaded fasteners 208a-208d. In this example, the threaded fasteners 208a-208d areAllen bolts, sometimes referred to as hexagonal socket bolts. However, in other examples, the threaded fasteners 208a-208d can be a different kind of bolt or screw. The hub 204 of the worm wheel 118 has a first axial end 601 and a second axial end 603 opposite the first axial end 601. The central opening 120 extends through the hub 204 between the first axial end 601 and the second axial end 603. The central opening 120 is defined by an inner surface 600 of the hub 204 of the worm wheel 118.

[0038] The sleeve 126 has a first axial end 602, a second axial end 604 opposite the first axial end 604, and an outer side surface 606 between the first axial end 602 and the second axial end 604. The sleeve 126 defines the keyed opening 128. In this example, the keyed opening 128 extends through the sleeve 126 between the first and second axial ends 602, 604. However, in other examples, the keyed opening 128 may only extend partially into the second axial end 604 and may not extend all the way to the first axial end 602.

[0039] In the illustrated example, the threaded fasteners 208a-208d are screwed into threaded fastener bores (which may also be referred to as bores or threaded bores) that are partially formed by the hub 204 of the worm wheel 118 and partially formed by the sleeve 126. For example, as shown in FIG. 6, a first threaded fastener bore 608a is partially formed on the inner surface 600 of the worm wheel 118 and partially formed in the outer side surface 606 of the sleeve. The first threaded fastener bore 608 extends into the first axial ends 601, 602 of the hub 204 and the sleeve 126 and along the inner and outersurfaces 600, 606. In particular, the inner surface 600 of the worm wheel 118 has or forms a first portion 610 of the first threaded fastener bore 608a, and the outer side surface 606 of the sleeve 126 has or forms a second portion 612 of the first threaded fastener bore 608a. In this example, the first and second portions 610, 612 each form half (e.g., a hemispherical portion or section) or substantially half of the first threaded bore 608a. The first and second portions 610, 612 are aligned to form the first threaded fastener bore 608a. When the first threaded fastener 208a is screwed into the first threaded fastener bore 608a, the interface between the first threaded fastener 208a with the worm wheel 118 and the sleeve 126 rotationally constrains or locks the sleeve 126 relative to the worm wheel 1 18. In some examples, one of the portions 610, 612 is threaded, while the other portion 610, 612 is not threaded (e g., is a plain or smooth bore portion). For example, as shown in FIG. 6, the first portion 610 on the inner surface 600 of the worm wheel 118 has threads, while the second portion 612 on the outer surface 606 of the sleeve 126 does not have threads. Therefore, when the first threaded fastener 208a is screwed into the first bore 608a, the first threaded fastener 208a becomes threaded into the threads on the first portion 610. In some instances, it may be difficult to ensure that threads formed on each of the portions 610, 612 are aligned.Therefore, having threads on only one of the portions 610, 612 ensures there is no assembly difficultly, but still enables the first threaded fastener 208a to be screwed into the first threaded bore 608a to couple the parts together. In other examples, the second portion 612 may be threaded while the first portion 610 is not threaded. In still other examples, both of the portions 610, 612 may bethreaded. In such an example, half of the threads of the first threaded fastener bore 608a are formed on the inner surface 600 of the worm wheel 118, and the other half of the threads of the first threaded fastener bore 608a are formed on the outer side surface 606 of the sleeve 126. The worm wheel 118 and the sleeve 126 similarly form second, third, and fourth threaded fastener bores 608b, 608c, 608d for the second, third, and fourth threaded fasteners 208a, 208c, 208d. Therefore, the worm wheel 118 and the sleeve 126 form multiple threaded fastener bores, where each of the threaded fastener bores is formed partially on the inner surface 600 of the worm wheel 118 and partially on the outer side surface 606 of the sleeve 126, and each of the bores can be partially or fully threaded similar to the first threaded fastener bore 608a described above. This connection arrangement forms a relatively tight interface capable of transferring high torque loads between the worm wheel 118 and the sleeve 126.

[0040] The threaded fastener bores 608a-608d can be designed to extend any depth into the hub 204 and the sleeve 126. In this example, the threaded fastener bores 608a-608d extend about half way between the first and second axial ends 601, 603 of the worm wheel 118. In general, longer threaded engagements provide greater strength and reduce (e.g., minimize) stripping. However, in other examples, the threaded fastener bores 608a-608d can extend different depths into the hub 204 and the sleeve.

[0041] As shown in FIG. 6, the inner surface 600 of the worm wheel 118 has a shoulder 614 that extends radially inward at or near the second axial end 603. The shoulder 614 has a smaller diameter than the outer diameter ofthe sleeve 126. Therefore, the second axial end 604 of the sleeve 126 is engaged with the shoulder 614. When the threaded fasteners 208a-208d are screwed into the threaded fastener bores 608a-608d, the sleeve 126 is axially clamped between the threaded fasteners 208a-208d (e g., the heads of the threaded fasteners 208a-208d) and the shoulder 614. This axially constrains the sleeve 126 in the worm wheel 118. Therefore, the sleeve 126 is rotationally and axially constrained in the worm wheel 118 by the threaded fasteners 208a-208d. This connection provides a rigid interface for transferring high torque loads between the worm wheel 118 and the valve stem 110 (FIG. 1). In other examples, the sleeve 126 can be axially constrained via other mechanisms, such as using a circlip.

[0042] As shown in FIG. 6, the sleeve 126 has a central or longitudinal axis 616. In this example, each of the threaded fasteners 208a-208d is oriented in a direction that is parallel to the central axis 616. In other words, the threaded fasteners 208a-208d are oriented in an axial direction, rather than a radial or transverse orientation. However, in other examples, the fasteners 208a-208d can be oriented in other directions. For example, the threaded fasteners 208a-208d can be oriented in the radial direction and screwed radially into the hub 204 of the worm wheel 118 and into the sleeve 126.

[0043] FIG. 7 is an exploded view of the worm wheel 118, the sleeve 126, and the threaded fasteners 208a-208d. The half portions of the threaded fastener bores 608a-608d can be seen in FIG. 7. As shown in FIG. 7, the portions on the worm wheel 118 are threaded, while the portions on the sleeve126 are not threaded. However, in other examples, the portions on the sleeve126 can also be threaded.

[0044] In some examples, the sleeve 126 may include an indicator to help align the sleeve 126 with the hub 204 during assembly (e.g., when the sleeve 126 is inserted into the hub 204). For example, as shown in FIGS. 6 and 7, a line 618 is provided on the first axial end 602 of the hub 204 of the worm wheel 118.

[0045] In some examples, the sleeve 126, the hub 204, and / or another component can include an indicator to provide a visual indication of the position or state of the valve 102 (FIG. 1). For example, referring briefly back to FIG. 4, the top of the housing 1 16 of the gearbox 100 includes text indicating “CLOSE” and “OPEN.” When the valve 102 is open, the indicator points to the OPEN text, whereas when the valve 102 is closed, the indicator points to the CLOSE text. This enables a person to easily see the state or position of the valve 102.

[0046] In some examples, the gearbox 100 may include a cover plate for indicating the position of the valve 102. For example, as shown in FIG. 7, the gearbox 100 can include a cover plate 700. The cover plate 700 is a circular plate or disc. The cover plate 700 can be coupled to the top of the hub 204 of the worm wheel 118. For example, the first axial end 601 of the hub 204 has threaded bores 702a, 702b. Two threaded fasteners 704a, 704b can be screwed into the threaded bores 702a, 702b to couple the cover plate 700 to the worm wheel 118. In other examples, the cover plate 700 can be coupled to the worm wheel 118 via other techniques. In the illustrated example, thecover plate 700 has four openings 706 (one of which is reference in FIG. 7) to accommodate the heads of the threaded fasteners 208a-208d so the cover plate700 can he flat on the top of the first axial end 601 of the hub 204. The cover plate 700 can have indicia, such as an arrow 708, to indicate a position of the valve 102 (FIG. 1). For example, depending on the angle of the worm wheel 118, the arrow 708 on the cover plate 700 points to the OPEN or CLOSE text on the top of the gearbox 100.

[0047] In some examples, the threaded fastener bores 608a-608d (and, thus, the threaded fasteners 208a-208d) are spaced equidistant around the central axis 616 of the sleeve 126. In this example, there are four threaded fastener bores 608a-608d. Therefore, the threaded fastener bores 608a-68d are spaced at 90° increments around the central axis 616. This enables the sleeve 126 to be coupled to the worm wheel 118 at four different angles or orientations relative to the worm wheel 118. In particular, the sleeve 126 can be rotated at 90° increments to align the threaded bore portions on the sleeve 126 with the threaded bore portions on the worm wheel 118. For example, depending on the location of the key feature 300 (FIG. 3) on the valve stem 110 (FIG. 3), it may be desired to change the orientation of the sleeve 126 to match the direction of the key feature 300. This may be advantageous if the shape of the keyed opening in the sleeve 126 is asymmetric. For example, FIGS. 8A-8D show the sleeve 126 rotated to four different orientations relative to the worm wheel 118. This enables the notch 304 of the keyed opening 128 to be changed to four different directions to align with the key feature 300 (FIG. 3) on the valve stem (FIG. 3). Therefore, the arrangement ofthe four threaded fastener bores 608a-608d enables the sleeve 126 to be positioned in four different orientations or directions. This also enables the gearbox 100 to be re-positioned relative to the valve 102. For example, because of nearby objects, it may be desired or necessary to orient the gearbox 100 in a specification direction to avoid the nearby objects. The gearbox 100 can be positioned in the desired orientation and the sleeve 126 can be adjusted to match the location of the valve stem 110 (FIG. 1).

[0048] While in this example four threaded fasteners are used to couple the sleeve 126 to the worm wheel 118, in other examples, more or fewer threaded fasteners may be used. For instance, in some examples, only one threaded fastener is used. Therefore, in some examples, the worm wheel 1 18 and the sleeve 126 may only have or form one threaded fastener bore (e.g., the first threaded bore 608a). In other examples, the worm wheel 118 and the sleeve 126 can have or form more threaded fastener bores, such as two, three, five, six, etc.. The threaded fastener bores can be spaced equidistant from each other to enable the sleeve 126 to be rotated to different orientations.

[0049] The sleeve 126 can also be replaced or interchanged with a sleeve having a differently shaped keyed opening. The sleeve 126 can be easily replaced or interchanged by removing the threaded fasteners 208a-208d, removing the sleeve 126 from the worm wheel 118, inserting a new sleeve, and re-installing the threaded fasteners 208a-208d. For example, FIGS. 9A and 9B show examples of different sleeves 900, 902 having differently shaped keyed openings. The sleeve 900 in FIG. 9A has a square bore shaped opening.The sleeve 902 in FIG. 9B has a flat head shape opening. Therefore, the same gearbox 100 can be used with different types of valves having differently shaped valve stems. The only component that is changed is the sleeve, which is relatively inexpensive to manufacture and easy to install. While FIGS. 9A and 9B illustrate two example keyed openings, it is understood that the sleeve can have other shaped openings to match any shape (e.g., a cross-sectional shape) on a valve stem (e.g., a star shape, a hexagonal shape, splines, etc.).

[0050] In some examples, a manufacturer of the gearbox 100 can make multiple sleeves with differently shaped openings. Then, the manufacturer can provide a sleeve that fits the valve stem for a particular application. In some examples, a blank sleeve may be provided to drill or form an opening in the sleeve based on the desired keyed shape. For example, FIG. 10 illustrates an example of a sleeve 1000 having a pilot bore 1002. The pilot bore 1002 can be used to center a drill bit or other machinery. A user can drill or form a custom shaped opening in the sleeve 1000 to fit a particular valve stem. In the example of FIG. 10, the sleeve 1000 has an indicator 1004 (e.g., a line) that can be aligned with an indicator 1006 on the hub 204 of the worm wheel 118 when inserting the sleeve 1000.

[0051] In some examples, an existing worm wheel with a specific keyed shaped opening can be retrofitted with the example sleeve design disclosed herein. For instance, FIG. 11 A shows a known worm wheel 1100 that has a keyed opening 1102 in a hub 1104 of the worm wheel 1100.Therefore, the worm wheel 1100 can only be used with a valve stem havingthe exact shape of the keyed opening 1102 and can only be oriented in one direction.

[0052] As an example retrofitting process, the hub 1104 can be drilled out to form a larger central opening 1106, as shown in FIG. 1 IB. The central opening 1106 corresponds to the central opening 120 of the worm wheel 118 disclosed above. Then, as shown in FIG. 11C, multiple threaded bore portions 1108 can be formed on an inner surface 1110 of the central opening 1106. Therefore, any of the above disclosed sleeves can be inserted into the hub 1104 and coupled to the worm wheel 1100 via threaded fasteners. As a result, the worm wheel 1100 can be easily modified to incorporate sleeves having various key opening shapes to enable the gearbox to be used with different types of valves. This example process can be extremely advantageous to a manufacturer that has existing worm wheels with fixed keyed openings.

[0053] FIG. 12 is a flowchart representative of an example method 1200 of retrofitting an existing w orm wheel with an example sleeve. At block 1202, the method 1200 includes forming, such as via a machining process, a central opening in a hub of the worm wheel. In some examples, the central opening is formed by drilling. For example, with the worm wheel 1100 that had an existing keyed opening 1102 (FIG. 11 A), the hub 1104 can be drilled out to form the central opening 1106 (FIG. 11B).

[0054] At block 1204, the method 1200 includes forming, such as via a drilling and tapping process, one or more threaded bore portions on an inner surface of the central opening. For example, as shown in connection with the worm wheel 1100 in FIG. 11C, threaded bore portions 1108 are formed on theinner surface 1110 of the hub 1104 that defines the central opening 1106. The arrangement and / or spacing of the threaded bore portions 1108 may be formed to match the bore portions on a sleeve, such as the sleeve 126. In some examples, the process occurs while the worm wheel 1100 is removed from a gearbox. After the central opening and threaded bore portions are formed, the worm wheel 1100 can be re-installed in the gearbox.

[0055] After the threaded bore portions are formed, a sleeve with a desired keyed shaped opening can be inserted into the central opening and coupled to the sleeve. At block 1206, the method 1200 includes inserting a sleeve into the central opening of the worm wheel. For example, one of the sleeves 126, 900 902 can be inserted into the central opening 1 106 of the worm wheel 1 100. The selected sleeve is inserted into the central opening 1106 such that the bore portions on the sleeve are aligned with the threaded bore portions 1108 on the worm wheel 1100, thereby forming threaded bores that extend in an axial direction.

[0056] Then, at block 1208, the method 1200 includes coupling the sleeve to the worm wheel via threaded fasteners (e.g., bolts, screws). For example, one or more threaded fasteners (e.g., the threaded fasteners 208a- 208d) can be inserted into the threaded fastener bores that formed between the sleeve and the worm wheel 1100. This rotationally and axially constrains the sleeve in the central opening 1106 of the worm wheel 1100. The worm wheel 1100 with the sleeve can then be attached to a stem of a valve. The selected sleeve can be easily adjusted to another orientation depending on the direction of the keyed interface on the valve stem, as disclosed above in connection withFIGS. 8A-8D. Further, the selected sleeve can also be easily removed and replaced with another sleeve having a differently shaped keyed opening, as disclosed above.

[0057] An example method of constructing a sleeve (e.g., the sleeve 126) includes starting with a cylindrical stock of material (e.g., metal) having a first axial end, a second axial end opposite the first axial end, and an outer side surface between the first and second axial ends. Then, one or more portions of the threaded fasteners bores are formed (e.g., drilled) in the outer side surface. The portions extend in an axial direction along the outer side surface. The portions start at one of the axial ends and extend along the outer side surface. Tn some examples, the portions are smooth or plain. Tn other examples, threads can be formed on the portions. Tn some examples, a pilot bore is drilled in the sleeve (e.g., in the first axial end). Additionally or alternatively, a keyed opening can be formed (e.g., drilled, machined, etc.) in the sleeve.

[0058] While the example sleeve and gear connections are disclosed in conjunction with a worm wheel, it is understood the examples disclosed herein can also be used with other types of gears, such as traditional spur gears, helical gears, and / or any other type of gear that may be implemented in a gear box. Further, while the example gearboxes are described in connection with valves, the example gearboxes with the example sleeve designs disclosed herein can be implemented in any application where it is desired to transfer rotational motion and / or torque between a gear and a rotatable member. For example, the examples disclosed herein can be used in connection with theautomotive industry, the machine tool industry', and / or the material handling industry.

[0059] As used in this patent, stating that any part (e.g., a layer, film, area, region, or plate) is in any way on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, indicates that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween.

[0060] As used herein, connection references (e.g., attached, coupled, connected, and joined) may include intermediate members between the elements referenced by the connection reference and / or relative movement between those elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and / or in fixed relation to each other. As used herein, stating that any part is in “contact” with another part is defined to mean that there is no intermediate part between the two parts.

[0061] Unless specifically stated otherwise, descriptors such as “first,” “second,” “third,” etc., are used herein without imputing or otherwise indicating any meaning of priority, physical order, arrangement in a list, and / or ordering in any way, but are merely used as labels and / or arbitrary names to distinguish elements for ease of understanding the disclosed examples. In some examples, the descriptor “first” may be used to refer to an element in the detailed description, while the same element may be referred to in a claim with a different descriptor such as “second” or “third.” In such instances, it should be understood that such descriptors are used merely foridentifying those elements distinctly within the context of the discussion (e.g., within a claim) in which the elements might, for example, otherwise share a same name.

[0062] As used herein, “approximately” and “about” modify their subjects / values to recognize the potential presence of variations that occur in real world applications. For example, “approximately” and “about” may modify dimensions that may not be exact due to manufacturing tolerances and / or other real world imperfections as will be understood by persons of ordinary skill in the art. For example, “approximately” and “about” may indicate such dimensions may be within a tolerance range of + / - 10% unless otherwise specified in the below description.

[0063] “Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, having, etc.) as a preamble or within a claim recitation of any kind, it is to be understood that additional elements, terms, etc., may be present without falling outside the scope of the corresponding claim or recitation. As used herein, when the phrase “at least” is used as the transition term in, for example, a preamble of a claim, it is open-ended in the same manner as the term “comprising” and “including” are open ended. The term “and / or” when used, for example, in a form such as A, B, and / or C refers to any combination or subset of A, B, C such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, or (7) A with B and with C. As used herein in the context of describing structures, components, items,objects and / or things, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects and / or things, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities, etc., the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities, etc., the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B.

[0064] As used herein, singular references (e.g., “a”, “an”, “first”, “second”, etc.) do not exclude a plurality. The term “a” or “an” object, as used herein, refers to one or more of that object. The terms “a” (or “an”), “one or more”, and “at least one” are used interchangeably herein. Furthermore, although individually listed, a plurality of means, elements, or actions may be implemented by, e.g., the same entity or object. Additionally, although individual features may be included in different examples or claims, these may possibly be combined, and the inclusion in different examples or claims does not imply that a combination of features is not feasible and / or advantageous.

[0065] From the foregoing, it will be appreciated that example systems, apparatus, articles of manufacture, and methods have been disclosed that enable a gearbox to be easily adapted for connection to various valves having different valve stem / shaft shapes. The examples disclosed herein provide economical, robust, reliable, and adaptable sleeves for gearboxes to enable customers and distributors to maintain inventory for overcoming long lead time difficulties. The examples disclosed herein reduce the number of variants of worm wheels, which reduces overhead costs. The example sleeve and gear connections disclosed herein achieve excellent fatigue life. The example sleeve and gear connections disclosed herein are also relatively strong and provide excellent torque transfer due to the distributed load through the thread engagement.

[0066] Example and combinations of examples disclosed herein include the following:

[0067] Example 1 a gearbox for a valve, the gearbox comprising: a housing; a gear in the housing, the gear having a central opening defined by an inner surface of the gear, the inner surface having a first portion of a threaded fastener bore: a sleeve in the central opening of the gear, the sleeve having a first axial end, a second axial end, and an outer side surface between the first and second axial ends, the sleeve defining a keyed opening to receive a stem or shaft of the valve, the outer side surface of the sleeve having a second portion of the threaded fastener bore, the first portion and the second portion aligned to form the threaded fastener bore; and a threaded fastener screwed into the threaded fastener bore to couple the gear and the sleeve.

[0068] Example 2 includes the gearbox of Example 1, wherein the first portion is threaded and the second portion is not threaded.

[0069] Example 3 includes the gearbox of Example 1, wherein both the first portion and the second portion are threaded.

[0070] Example 4 includes the gearbox of any of Examples 1-3, wherein the threaded fastener is oriented in a direction that is parallel to a central axis of the sleeve.

[0071] Example 5 includes the gearbox of any of Examples 1-4, wherein the gear and the sleeve form multiple threaded fastener bores, each of the threaded fastener bores being formed partially on the inner surface of the gear and partially formed on the outer side surface of the sleeve.

[0072] Example 6 includes the gearbox of Example 5, wherein the threaded fastener bores are spaced equidistant around a central axis of the sleeve.

[0073] Example 7 includes the gearbox of Examples 5 or 6, wherein the gear and the sleeve form four threaded fastener bores.

[0074] Example 8 includes the gearbox of any of Examples 1-7, wherein the inner surface of the gear has a shoulder, the second axial end of the sleeve engaged with the shoulder.

[0075] Example 9 includes the gearbox of any of Examples 1-8, wherein the sleeve is constructed of carbon steel.

[0076] Example 10 includes the gearbox of any of Examples 1-9, wherein the gear is a worm wheel of a worm gear assembly.

[0077] Example 11 includes the gearbox of any of Examples 1-10, further including a cover plate coupled to a top of a hub of the worm wheel, the cover plate having indicia to indicate a position of the valve.

[0078] Example 12 includes the gearbox of any of Examples 1-11, wherein the threaded fastener is a bolt.

[0079] Example 13 is a worm gear assembly comprising: a worm; a worm wheel including a hub and a disc portion with teeth, the disc portion extending radially from the hub, the hub defining a central opening; a sleeve in the central opening, the worm wheel and the sleeve forming a threaded fastener bore partially formed on an inner surface of the worm wheel and partially formed on an outer side surface of the sleeve; and a threaded fastener screwed into the threaded fastener bore to couple the worm wheel and the sleeve.

[0080] Example 14 includes the worm gear assembly of Example 13, wherein the worm wheel and the sleeve form multiple threaded fastener bores, each of the threaded fastener bores being formed partially on the inner surface of the worm wheel and partially formed on the outer side surface of the sleeve.

[0081] Example 15 includes the worm gear assembly of Example 14, wherein the threaded fastener bores are spaced equidistant around a central axis of the sleeve.

[0082] Example 16 includes the worm gear assembly of any of Examples 13-15, wherein the sleeve has a pilot bore.

[0083] Example 17 includes a worm wheel of a worm gear assembly, the worm wheel comprising: a disc portion with teeth; and a hub, the discportion extending radially from the hub, the hub defining a central opening, an inner surface of the central opening having a portion of a threaded bore.

[0084] Example 18 includes the worm wheel of Example 17, wherein the portion of the threaded fastener bore extends in an axial direction on the inner surface.

[0085] Example 19 includes the worm wheel of Examples 17 or 18, wherein the inner surface of the central opening has multiple portions of threaded bores.

[0086] Example 20 is a sleeve to be inserted into a central opening of a gear to interface with a stem or shaft of a valve, the sleeve comprising: a first axial end; a second axial end opposite ethe first axial end; and an outer side surface between the first axial end and the second axial end, the outer side surface having a portion of a threaded bore fastener.

[0087] Example 21 includes the sleeve of Example 20, wherein the portion of the threaded fastener bore extends in an axial direction on the outer side surface.

[0088] Example 22 includes the sleeve of Examples 20 or 21, wherein the sleeve defines a keyed opening extending between the first axial end and the second axial end.

[0089] Example 23 is a method comprising: drilling a central opening in a hub of a worm wheel; forming a first portion of a threaded fastener bore on an inner surface of the hub that forms the central opening; and inserting a sleeve into the central opening, the sleeve having a second portion of the threaded fastener bore, the sleeve inserted into the central opening such thatthe second portion aligns with the first portion to form the threaded fastener bore.

[0090] Example 24 includes the method of Example 23, further including coupling the sleeve to the worm wheel by screwing a threaded fastener into the threaded fastener bore.

[0091] Example 25 includes the method of Examples 23 or 24, further including forming multiple portions of multiple threaded fasteners bores on the inner surface of the hub that forms the central opening.

[0092] The following claims are hereby incorporated into this Detailed Description by this reference. Although certain example systems, apparatus, articles of manufacture, and methods have been disclosed herein, the scope of coverage of this patent is not limited thereto On the contrary, this patent covers all systems, apparatus, articles of manufacture, and methods fairly falling within the scope of the claims of this patent.

Claims

What Is Claimed Is:

1. A gearbox for a valve, the gearbox comprising: a housing; a gear in the housing, the gear having a central opening defined by an inner surface of the gear, the inner surface having a first portion of a threaded fastener bore; a sleeve in the central opening of the gear, the sleeve having a first axial end, a second axial end, and an outer side surface between the first and second axial ends, the sleeve defining a keyed opening to receive a stem or shaft of the valve, the outer side surface of the sleeve having a second portion of the threaded fastener bore, the first portion and the second portion aligned to form the threaded fastener bore; and a threaded fastener screwed into the threaded fastener bore to couple the gear and the sleeve.

2. The gearbox of claim 1, wherein the first portion is threaded and the second portion is not threaded.

3. The gearbox of claim 1, wherein both the first portion and the second portion are threaded.

4. The gearbox of any of claims 1-3, wherein the threaded fastener is oriented in a direction that is parallel to a central axis of the sleeve.

5. The gearbox of any of claims 1-4, wherein the gear and the sleeve form multiple threaded fastener bores, each of the threaded fastener bores being formed partially on the inner surface of the gear and partially formed on the outer side surface of the sleeve.

6. The gearbox of claim 5, wherein the threaded fastener bores are spaced equidistant around a central axis of the sleeve.

7. The gearbox of claims 5 or 6, wherein the gear and the sleeve form four threaded fastener bores.

8. The gearbox of any of claims 1 -7, wherein the inner surface of the gear has a shoulder, the second axial end of the sleeve engaged with the shoulder.

9. The gearbox of any of claims 1-8, wherein the sleeve is constructed of carbon steel.

10. The gearbox of any of claims 1-9, wherein the gear is a worm wheel of a worm gear assembly.

11. The gearbox of any of claims 1-10, further including a cover plate coupled to a top of a hub of the worm wheel, the cover plate having indicia to indicate a position of the valve.

12. The gearbox of any of claims 1-11, wherein the threaded fastener is a bolt13. A worm gear assembly comprising: a worm; a worm wheel including a hub and a disc portion with teeth, the disc portion extending radially from the hub, the hub defining a central opening; a sleeve in the central opening, the worm wheel and the sleeve forming a threaded fastener bore partially formed on an inner surface of the worm wheel and partially formed on an outer side surface of the sleeve; and a threaded fastener screwed into the threaded fastener bore to couple the worm wheel and the sleeve.

14. The worm gear assembly of claim 13, wherein the worm wheel and the sleeve form multiple threaded fastener bores, each of the threaded fastener bores being formed partially on the inner surface of the worm wheel and partially formed on the outer side surface of the sleeve.

15. The worm gear assembly of claim 14, wherein the threaded fastener bores are spaced equidistant around a central axis of the sleeve.

16. The worm gear assembly of any of claims 13-15, wherein the sleeve has a pilot bore.

17. A worm wheel of a worm gear assembly, the worm wheel comprising: a disc portion with teeth; and a hub, the disc portion extending radially from the hub, the hub defining a central opening, an inner surface of the central opening having a portion of a threaded bore.

18. The worm wheel of claim 17, wherein the portion of the threaded fastener bore extends in an axial direction on the inner surface.

19. The worm wheel of claims 17 or 18, wherein the inner surface of the central opening has multiple portions of threaded bores.

20. A sleeve to be inserted into a central opening of a gear to interface with a stem or shaft of a valve, the sleeve comprising: a first axial end; a second axial end opposite ethe first axial end; and an outer side surface between the first axial end and the second axial end, the outer side surface having a portion of a threaded bore fastener.

21. The sleeve of claim 20, wherein the portion of the threaded fastener bore extends in an axial direction on the outer side surface.

22. The sleeve of claims 20 or 21, wherein the sleeve defines a keyed opening extending between the first axial end and the second axial end.

23. A method comprising: drilling a central opening in a hub of a worm wheel; forming a first portion of a threaded fastener bore on an inner surface of the hub that forms the central opening; and inserting a sleeve into the central opening, the sleeve having a second portion of the threaded fastener bore, the sleeve inserted into the central opening such that the second portion aligns with the first portion to form the threaded fastener bore.

24. The method of claim 23, further including coupling the sleeve to the worm wheel by screwing a threaded fastener into the threaded fastener bore.

25. The method of claims 23 or 24, further including forming multiple portions of multiple threaded fasteners bores on the inner surface of the hub that forms the central opening.

Images