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Title:
A BUTTERFLY VALVE, A METHOD FOR ROTATABLY LOCKING A DISC OF A BUTTERFLY VALVE AND USE OF A BUTTERFLY VALVE
Document Type and Number:
WIPO Patent Application WO/2019/174685
Kind Code:
A1
Abstract:
Disclosed is a butterfly valve (1)comprising a valve housing (2)and a rotatable disc (3)arranged to rotate between a blocking position, in which the disc (3)will block flow through the housing (2), and an open position in which the disc (3)will enable flow through the housing (2). The butterfly valve (1)further comprises a drive shaft (4)connected to the disc (3)and through which rotation of the disc (3)between the blocking position and the open position is at least partly enabled and the butterfly valve (1)comprises drive shaft locking means (5)arranged to lock the disc (3)against rotation at least in the blocking position or the open position, wherein the drive shaft locking means (5)comprises a removable locking pawl (6)including pawl engagement means (7)arranged to engage shaft engagement means (8)of the drive shaft (4), wherein the locking pawl (6)is maintained in the engagement by means of separate mechanical fastening means (9)arranged to releasably fix the locking pawl (6)to form backlash-freedrive shaft locking means (5). A method for rotatably locking a disc (3)of a butterfly valve (1)and use of a butterfly valve (1)is also disclosed.

Inventors:
DE KLERK NICOLAAS CORNELIUS (ZA)
Application Number:
DK2018/050046
Publication Date:
September 19, 2019
Filing Date:
March 15, 2018
Export Citation:
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Assignee:
AVK HOLDING AS (DK)
International Classes:
F16K1/22
Foreign References:
US5370148A1994-12-06
US20120193558A12012-08-02
US20130056667A12013-03-07
JP2004251362A2004-09-09
Attorney, Agent or Firm:
PATENTGRUPPEN A/S (4th floor, 8000 Aarhus C, DK)
Download PDF:
Claims:
Claims

1. A butterfly valve (1) comprising, a valve housing (2), a rotatable disc (3) arranged to rotate between a blocking position, in which said disc (3) will block flow through said housing (2), and an open position in which said disc

(3) will enable flow through said housing (2), a drive shaft (4) connected to said disc (3) and through which rotation of said disc (3) between said blocking position and said open position is at least partly enabled, drive shaft locking means (5) arranged to lock said disc (3) against rotation at least in said blocking position or said open position, wherein said drive shaft locking means (5) comprises a removable locking pawl (6) including pawl engagement means (7) arranged to engage shaft engagement means (8) of said drive shaft (4), wherein said locking pawl (6) is maintained in said engagement by means of separate mechanical fastening means (9) arranged to releasably fix said locking pawl (6) to form backlash- free drive shaft locking means (5).

2. Abutterfly valve (1) according to claim 1, wherein said butterfly valve (1) comprises drive means (10) arranged to drive the rotation of said disc (3) through said drive shaft

(4) and wherein said drive shaft locking means (5) is arranged between said disc (3) and said drive means (10).

3. A butterfly valve (1) according to claim 1 or 2, wherein said valve housing (2) comprises a pawl orifice (11) in which at least a part of said locking pawl (6) is arranged to engage said drive shaft (4) and wherein said pawl orifice (11) extends radially in relation to said drive shaft (4).

4. A butterfly valve (1) according to claim 3, wherein the cross section of said pawl orifice (11) substantially corresponds to a cross section of said locking pawl (6).

5. A butterfly valve (1) according to claim 3 or 4, wherein said locking pawl (6) comprises a mounting base (12) from which a pawl rod (13) protrudes and wherein at least said pawl rod (13) is arranged to extend into said pawl orifice (11) to engage said drive shaft (4).

6. A butterfly valve (1) according to claim 5, wherein said mounting base (12) comprises fixation means (14) enabling said separate mechanical fastening means (9) to releasably fix said locking pawl (6) in said engagement with said drive shaft (4).

7. A butterfly valve (1) according to any of the preceding claims, wherein said pawl engagement means (7) and said shaft engagement means (8) comprises a geometrical design arranged to increase mutual backlash-free engagement.

8. A butterfly valve (1) according to any of the preceding claims, wherein said pawl engagement means (7) includes a flat area (15) and said shaft engagement means (8) includes a matching flat area (16).

9. A butterfly valve (1) according to any of the preceding claims, wherein said drive shaft (4) comprises shaft engagement means (8) corresponding to said blocking position and shaft engagement means (8) corresponding to said open position.

10. A butterfly valve (1) according to any of the preceding claims, wherein said drive shaft locking means (5) comprises at least two separate locking pawls (6) arranged to engage at least two shaft engagement means (8).

11. A butterfly valve (1) according to any of the preceding claims, wherein said drive shaft locking means (5) is arranged so that the locking pawl (6) can be mounted in an inverted position in which said locking pawl (6) is not engaging said drive shaft (4) and wherein said locking pawl (6) is fixed in this invented position by said separate mechanical fastening means (9). 12. A butterfly valve (1) according to any of the preceding claims, wherein said drive shaft locking means (5) is arranged to lock said disc (3) against rotation at least in both said blocking position and said open position.

13. A butterfly valve (1) according to any of the preceding claims, wherein said drive means (10) comprises a manually operated handle (17) or a motor.

14. A method for rotatably locking a disc (3) of a butterfly valve (1), said method comprises the steps of

• positioning said disc (3) in a specific position by manipulating a drive shaft (4) connected to said disc (3),

• engaging pawl engagement means (7) of a locking pawl (6) with shaft engagement means (8) of said drive shaft (4),

• fixating said locking pawl (6) in said engaged position by means of separate mechanical fastening means (9).

15. A method according to claim 14, wherein said locking pawl (6) is inserted through a pawl orifice (11) in said valve housing (2) when said locking pawl (6) is arranged to engage said drive shaft (4), and wherein said locking pawl (6) is inserted radially through said radially extending pawl orifice (11).

16. A method according to claim 14 or 15, wherein the followings steps are performed before said locking pawl (6) is arranged to engage said drive shaft (4): • disengaging said separate mechanical fastening means (9) to un-fixate said locking pawl (6) from a disengaged position in which said locking pawl (6) is extending mainly away from said drive shaft (4),

• turning said locking pawl (6) around 180° so that said locking pawl (6) is extending mainly in a direction towards said drive shaft (4).

17. A method according to any of claims 14-16, wherein said butterfly valve (1) is a butterfly valve (1) according to any of claims 1-13. 18. Use of a butterfly valve (1) according to any of claims 1-13 for blocking the flow of a fluid through a pipe.

Description:
A BUTTERFLY VALVE, A METHOD FOR ROTATABLY LOCKING A DISC OF A BUTTERFLY VALVE AND USE OF A BUTTERFLY VALVE

Field of the invention

The invention relates to a butterfly valve comprising a valve housing and a rotatable disc arranged to rotate between a blocking position, in which the disc will block flow through the housing, and an open position, in which the disc will enable flow through the housing. The invention further relates to a method for rotatably locking a disc of a butterfly valve and use of a butterfly valve is also disclosed.

Background of the invention

A butterfly valve is a valve that isolates or regulates the flow of a fluid by rotating a disk located in the flow, wherein the disc is rotated between parallel and

perpendicular to the flow. Unlike e.g. ball valves, the disc is always present within the flow, so it induces a pressure drop, even when open.

In operation, a butterfly valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a disc provided with at least one drive shaft e.g. in the form of a transverse rod, a shaft extending from one side or two opposite sides of the disc or other. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid. However, the disc is still located in the fluid flow even when the valve is fully open. The valve may also be opened incrementally to throttle flow.

Particularly in relation to larger butterfly valves it is known to actuate the drive shaft by means of a large handle or even a motor. Sometimes through some sort of gearing arrangement. And e.g. if the gearing arrangement, the actuation means, the disc or other has to be repaired, maintained or replaced - or even as a part of normal operation of a butterfly valve - it is sometimes necessary to be able to lock the disc in a fixed position by means of some sort of locking means. However, movement in the fluid, vortices or other will still affect the disc and it is therefore important that the locking means are substantially backlash-free.

Thus, from the Japanese patent application JP 2004-251362 it is known to provide a butterfly valve with locking means in the form of a wedge-shaped pin arranged to be inserted into a hole intersecting the drive shaft of the disc, so that when the wedge is installed it will press against a flat part of the drive shaft. However, such a wedge is difficult to install correctly and even more difficult to remove. And dirt caught between the wedge and the shaft, incorrect positioning of the parts during installation of the wedge or other could lead to play between the wedge and the shaft and thus enable backlash.

An object of the invention is therefore to provide for an advantageous and cost- effective technique for locking rotation of a disc of a butterfly valve.

The invention

The invention provides for a butterfly valve comprising a valve housing and a rotatable disc arranged to rotate between a blocking position, in which the disc will block flow through the housing, and an open position in which the disc will enable flow through the housing. The butterfly valve further comprises a drive shaft connected to the disc and through which rotation of the disc between the blocking position and the open position is at least partly enabled and the butterfly valve comprises drive shaft locking means arranged to lock the disc against rotation at least in the blocking position or the open position, wherein the drive shaft locking means comprises a removable locking pawl including pawl engagement means arranged to engage shaft engagement means of the drive shaft, wherein the locking pawl is maintained in the engagement by means of separate mechanical fastening means arranged to releasably fix the locking pawl to form backlash-free drive shaft locking means.

Providing a butterfly valve with a locking pawl that is maintained in engagement by means of separate mechanical fastening means is advantageous in that the fastening means will ensure that the locking pawl stays fully engaged no matter how the drive shaft affects the locking pawl. And even though the mechanical fastening means are releasable it will take some effort to remove them and thereby the fastening means will aid in protecting the drive shaft locking means against faulty or accidental operation.

It should be noted that in this context the term“drive shaft locking means” should be understood as any kind of drive shaft lock suitable for locking the disc of a butterfly valve against rotation - such as any kind of locking pin, peg, plug or other. Furthermore, in this context the term“pawl engagement means” should be understood as any kind of pawl surface suitable for acting as the engaging part of a removable locking pawl - such as any kind of end face, side face, a more or less complex surface, any kind of machined or cast geometry, indentation, protrusion or other or any combination thereof.

Also, in this context the term“shaft engagement means” should be understood as any kind of shaft geometry suitable for being engaged by pawl engagement means - such as any kind of machined or cast geometry, such as any kind of flat surface, a more or less complex surface, indentation, protrusion or other or any combination thereof.

Further, in this context the term“mechanical fastening means” should be understood as any kind of mechanical fastener suitable for maintaining pawl engagement means engaged with shaft engagement means - such as any kind of bolts, screws, catch, lock, clamp, cramp or other or any combination thereof. In an aspect of the invention, the butterfly valve comprises drive means arranged to drive the rotation of the disc through the drive shaft and wherein the drive shaft locking means is arranged between the disc and the drive means.

Arranging the drive shaft locking means between the disc and the drive means is advantageous in that the drive means hereby can be service or replaced while the disc is maintained in its position by the drive shaft locking means.

In an aspect of the invention, the valve housing comprises a pawl orifice in which at least a part of the locking pawl is arranged to engage the drive shaft and wherein the pawl orifice extends radially in relation to the drive shaft.

When the pawl orifice is arranged radially in relation to the drive shaft, the locking pawl will engage the drive shaft perpendicular to the rotational axis of the drive shaft. This is advantageous in that any form of wedging is avoided and in that through this design it is less complex to mechanically force and maintain the pawl engagement means in engagement with the shaft engagement means. Also, such a design requires less production tolerance.

In an aspect of the invention, the cross section of the pawl orifice substantially corresponds to a cross section of the locking pawl.

Forming the pawl orifice with substantially the same cross section as the locking pawl is advantageous in that it reduces the risk play between the pawl orifice and the locking pawl and thus reduces the risk of backlash.

In an aspect of the invention, the locking pawl comprises a mounting base from which a pawl rod protrudes and wherein at least the pawl rod is arranged to extend into the pawl orifice to engage the drive shaft. Forming the locking pawl with a pawl rod protruding from a mounting base is advantageous in that the base enable simple and solid fixation of the locking pawl.

In an aspect of the invention, the mounting base comprises fixation means enabling the separate mechanical fastening means to releasably fix the locking pawl in the engagement with the drive shaft.

Placing the fixation means on the mounting base is advantageous in that it enables simple and solid fixation of the locking pawl.

It should be noted that in this context the term“fixation means” should be understood as any kind of fixator suitable for enabling fastening means to releasably fix a locking pawl in the engagement with a drive shaft - such as any kind of hole, indentation, track, guide or other.

In an aspect of the invention, the pawl engagement means and the shaft engagement means comprises a geometrical design arranged to increase mutual backlash-free engagement.

Forming the pawl engagement means and the shaft engagement means with matching geometrical design - such as corresponding flat surfaces, interlocking protrusions and indentations, hook-like arrangement on one part and loop-like arrangement on the other part or other - is advantageous in that it increases mutual backlash-free engagement.

In an aspect of the invention, the pawl engagement means includes a flat area and the shaft engagement means includes a matching flat area.

Forming the pawl engagement means and the shaft engagement means with matching flat areas is advantageous in that it increases mutual backlash-free engagement and in that it is easy and inexpensive to form and thereby simple to form in relation to more than one disc angular position.

In an aspect of the invention, the drive shaft comprises shaft engagement means corresponding to the blocking position and shaft engagement means corresponding to the open position.

Forming the drive shaft so that it may be blocked both when the disc is in blocking position and in open position is advantageous in that this enables a more versatile valve and locking system.

In an aspect of the invention, the drive shaft locking means comprises at least two separate locking pawls arranged to engage at least two shaft engagement means. Forming the drive shaft locking means with two separate locking pawls arranged to engage two shaft engagement means is advantageous in that a stronger hold is ensured, the risk of faulty use is reduced and it reduces the risk of backlash.

In an aspect of the invention, the drive shaft locking means is arranged so that the locking pawl can be mounted in an inverted position in which the locking pawl is not engaging the drive shaft and wherein the locking pawl is fixed in this invented position by the separate mechanical fastening means.

Arranging the drive shaft locking means so that it can be fixed to the valve in an idle position is advantageous in that locking pawl and the separate mechanical fastening means are easily available when the drive shaft has to be locked. Furthermore, in the inverted position the locking pawl will protrude away from the drive shaft making it easy and safe to visually or tactile detect whether the locking pawl is engaging the drive shaft or not. In an aspect of the invention, the drive shaft locking means is arranged to lock the disc against rotation at least in both the blocking position and the open position.

Enabling that the disc can be locked in both the blocking position and the open position is advantageous in that this enables a more versatile valve and locking system.

In an aspect of the invention, the drive means comprises a manually operated handle or a motor.

Butterfly valves are often big or at least difficult to operate and it is therefore advantageous that the drive means comprises a manually operated handle or a motor.

The invention further provides for a method for rotatably locking a disc of a butterfly valve, the method comprises the steps of

• positioning the disc in a specific position by manipulating a drive shaft connected to the disc,

• engaging pawl engagement means of a locking pawl with shaft engagement means of the drive shaft,

• fixating the locking pawl in the engaged position by means of separate mechanical fastening means.

Fixating the locking pawl in the engaged position is advantageous in that it ensures a safer lock and it reduces the risk of backlash. And fixating the locking pawl by means of separate mechanical fastening means is advantageous in that they reduce the risk of faulty operation and enables that the locking pawl can be constantly forced into the engaged position, thus further reducing the risk of backlash. In an aspect of the invention, the locking pawl is inserted through a pawl orifice in the valve housing when the locking pawl is arranged to engage the drive shaft, and wherein the locking pawl is inserted radially through the radially extending pawl orifice.

Forcing the locking pawl radially onto the drive shaft is advantageous in that it enables easy engagement and disengagement and in that the locking pawl will lock equally well no matter which direction the drive shaft is affected in.

In an aspect of the invention, the followings steps are performed before the locking pawl is arranged to engage the drive shaft:

• disengaging the separate mechanical fastening means to un-fixate the locking pawl from a disengaged position in which the locking pawl is extending mainly away from the drive shaft,

• turning the locking pawl around 180° so that the locking pawl is extending mainly in a direction towards the drive shaft.

Engaging the locking pawl by simply disengaging it and flipping it around and reattaching it by means of the separate mechanical fastening means is advantageous in that it enables fast and safe operation of the locking pawl - and in that it enables easy visual and tactile detection of the state of the drive shaft locking means.

In an aspect of the invention, the butterfly valve is a butterfly valve according to any of the previously discussed butterfly valves.

The invention also provides for use of a butterfly valve according to any of the previously discussed butterfly valves for blocking the flow of a fluid through a pipe.

Using a butterfly valve according to any of the previously discussed butterfly valves for blocking the flow of a fluid through a pipe is advantageous in that pipes often have to be either open or blocked and it is therefore advantageous to us a butterfly valve according to the present invention.

Figures

An embodiment of the invention will be described, by way of non-limiting example, in the following with reference to the figures in which: fig. 1 illustrates a butterfly valve, as seen in perspective, fig. 2 illustrates a closeup of drive shaft locking means in a disengaged state, as seen in perspective, fig. 3 illustrates drive shaft locking means with fastening means disengaged, as seen in perspective, fig. 4 illustrates drive shaft locking means with locking pawl and fastening means disengaged, as seen in perspective, fig. 5 illustrates drive shaft locking means mounted in engaged state, as seen in perspective, fig. 6 illustrates a cross section through drive shaft locking means in the idle state shown in fig. 1 and 2, as seen from the side, and fig. illustrates a cross section through drive shaft locking means in the engaged state shown in fig. 5, as seen from the side. Detailed description

Fig. 1 illustrates a butterfly valve 1, as seen in perspective.

In this embodiment the butterfly valve 1 comprises a disc 3 suspended at both sides but only provided with drive means 10 at one side. However, in another embodiment the disc 3 could be provided with drive means 10 at both sides or the disc 3 would only be suspended at one side - e.g. if the drive means 10 was arranged at the upper part of the disc 3 instead of at the sides. In this embodiment the drive means 10 comprise a handle 17 arranged to act on the drive shaft 4 through a gear 18 - in this case a worm gear. However, in another embodiment drive means 10 could comprise a lever, an actuator, a motor or other and/or the drive means 10 could be geared another way - e.g. through a chain or belt drive, a planetary gear, spur gear or other - and/or the butterfly valve 1 would not comprise a gear 18.

In this embodiment the butterfly valve 1 is shown in a closed state in that the disc 3 is substantially vertical so that it rests against a seat on the surrounding valve housing 2 and thereby block flow through the opening covered by the disc 3. However, if the disc 3 is rotated 90 degrees to a substantially horizontal state, the valve 1 will be fully open.

Fig. 2 illustrates a closeup of drive shaft locking means 5 in a disengaged state, as seen in perspective.

In this embodiment the drive shaft locking means 5 comprises two separate locking pawls 6 each being formed by a mounting base 12 from which a pawl rod 13 protrudes. However, in another embodiment the drive shaft locking means 5 could comprise another number of locking pawls 6 - such as one, three, four or even more - and /or the locking pawl 6 could be formed in another way - such as as a tube, a pin, a cone or other.

In this embodiment the locking pawls 6 are mounted with the pawl rods 13 facing away from the drive shaft 4 - i.e. in this embodiment the drive shaft locking means 5 is shown in a disengaged state. In this embodiment the locking pawls 6 are releasably connected to the valve housing 2 by means of separate mechanical fastening means 9 in the form of bolts engaging corresponding bolt holes in the valve housing 2.

However, in another embodiment the locking pawls 6 could be connected to the valve housing 2 in a different way in the disengaged stated - e.g. by means of a hook, a storage box, a storage hole or other.

Fig. 3 illustrates drive shaft locking means 5 with fastening means 9 disengaged, as seen in perspective,

In this embodiment the fastening means 9 have been disengaged to enable that the locking pawl 6 may be removed.

Fig. 4 illustrates drive shaft locking means 5 with locking pawl 6 and fastening means 9 disengaged, as seen in perspective.

In this embodiment the locking pawl 6 has been turned 180° so that the pawl rod 13 is facing the pawl orifice 11 in the valve housing 2 and thereby facing the drive shaft 4.

Fig. 5 illustrates drive shaft locking means 5 mounted in engaged position, as seen in perspective.

In this embodiment the locking pawl 6 has been inserted into the pawl orifice 11 so that the pawl rod 13 may engage the drive shaft 4 and thus prevent it from rotating. To ensure that the locking pawl 6 is maintained in engagement with the drive shaft 4 the locking pawl 6 is releasably fixed by means of separate mechanical fastening means 9 in the form of two bolt protruding through fixation means 14 - in the form of holes - in either sides of the mounting base 12 of the locking pawl 6. However, in another embodiment each locking pawl 6 could be releasably fixed by another number of fastening means 9 - such as one, three, four or even more - and/or the fastening means 9 could be arranged differently in relation to the locking pawl 6 - such as a single centrally arranged fastening means 9 or other.

In this embodiment the same fastening means 9 are used for fixating the locking pawl 6 in engaged state and disengaged state to reduce number of parts and simplify the design. However, in another embodiment different means could be used for each state.

Fig. 6 illustrates a cross section through the drive shaft locking means 5 in the idle state shown in fig. 1 and 2, as seen from the side, and fig. 7 illustrates the same cross section through the drive shaft locking means 5 in the engaged state shown in fig. 5, as seen from the side.

In this embodiment the locking pawls 6 are provided with pawl engagement means 7 in the form of a flat areas 15 (flat end faces) of the pawl rods 13 arranged to engage shaft engagement means 8 in the form of corresponding flat areas 16 of the drive shaft 4 as best illustrated in fig. 7. However, in another embodiment the matching pawl engagement means 7 and shaft engagement means 8 could be formed in numerous other ways to ensure a substantially backlash-free engagement. However, it should be pointed out that the term“flat area” in this context means flat in at least one dimension. I.e. in figs. 2 and 3 it is shown that the upwardly facing pawl engagement means 7 of the locking pawl 6 facing upwards has a curved cross section as seen from the front, but seen from the side as in figs. 6 and 7 the cross section is linear and such a locking pawl 6 thus also comprises a pawl rod 13 with pawl engagement means 7 in the form of a flat area 15 in one dimension.

In this embodiment the valve housing 2 is provided with three different pawl orifices 11, thus enabling that two locking pawls 6 may engage the drive shaft 4 no matter if the disc 3 is in closed state - as it is in fig. 6 and 7 - or if it is in open state - i.e. turned 90°. However, in another embodiment the same result could be achieved by means of only two pawl orifices 11 and then provide the drive shaft 4 with at least three 90° offset shaft engagement means 8.

In this embodiment the pawl orifice 11 that is not in use is provided with a blanking plate 19.

In this embodiment the pawl orifices 11 are offset 90 degrees and the pawl orifices 11 are formed as relatively wide rectangular holes. However, in another embodiment the pawl orifices 11 could be offset in another angle - such as 45°, 60°, 180° or other - and/or the pawl orifices 11 could be formed with a different cross section - such as oval, square, circular or other.

In this embodiment the cross section of the pawl orifice 11 substantially corresponds to a cross section of the locking pawl 6. However, in another embodiment only parts of cross section of the pawl orifice 11 would correspond to the cross section of the locking pawl 6 - e.g. only parts of the longitudinal and transversal surfaces. In this embodiment, the pawl orifice 11 would have fit the locking pawl 6 to support the locking pawl 6 against movement in all directions perpendicular to the insertion direction of the locking pawl 6 into the pawl orifice 11 to reduce the risk of backlash. However, in another embodiment the the cross section of the pawl orifice 11 would be larger than the cross section of the locking pawl 6 and the position of the locking pawl 6 would be fixed during use by means of the mechanical fastening means 9, by means of the mounting base 12, by means of guiding pins or other or any

combination thereof.

The invention has been exemplified above with reference to specific examples of butterfly valves 1, drive shaft locking means 5, mechanical fastening means 9 and other. However, it should be understood that the invention is not limited to the particular examples described above but may be designed and altered in a multitude of varieties within the scope of the invention as specified in the claims.

List

1. Butterfly valve

2. Valve housing

3. Rotatable disc

4. Drive shaft

5. Drive shaft locking means

6. Locking pawl

7. Pawl engagement means

8. Shaft engagement means

9. Mechanical fastening means

10. Drive means

11. Pawl orifice

12. Mounting base

13. Pawl rod

14. Fixation means

15. Flat area of pawl engagement means

16. Flat area of shaft engagement means

17. Handle

18. Gear

19. Blanking plate