Guide element for a valve actuator and actuator provided with said guide element

Abstract

Disclosed is a guide element, for supporting and guiding a pin (P) of a glyph in a slot along a sliding direction. The guide element includes a central body (10) provided with a seat adapted to house a portion of the pin (P) and at least one lateral portion (10, 30) which has a sliding surface (21, 31) adapted to slide in contact with a respective lateral wall of the slot. The central body (10) and the at least one lateral portion (20, 30) are configured to rotate relative to each other about an axis (X) parallel to the sliding direction.

Claims

1. Guide element of a pin (P) in a valve actuator, adapted to support and guide said pin (P) in a slot of a glyph along a sliding direction, which comprises: a central body (10) provided with a seat adapted to house a portion of said pin (P); at least one lateral portion (10, 30) which has a sliding surface (21, 31) adapted to slide in contact with a respective lateral wall of the slot; wherein said central body (10) and said at least one lateral portion (20, 30) are configured to rotate relative to each other about an axis (X) parallel to the sliding direction, and wherein the guide element further comprises constraint means adapted to constrain the translation of the at least one lateral portion (20, 30) with respect to the central body (10) along a direction (X) parallel to the sliding direction.

2. The guide element according to claim 1, wherein the central body has at least one outer bearing surface (12, 13), at least partly cylindrical, whose axis (X) is parallel to the sliding direction, and the at least one lateral portion (20, 30), on an inner face (20c, 30c), has a corresponding inner bearing surface (22, 32) at least partly cylindrical, adapted to rotate in contact with the outer bearing surface (12, 13).

3. The guide element according to claim 2, wherein the outer bearing surface (12, 13) extends by the entire length of the central body (10).

4. The guide element according to claim 2, wherein the inner bearing surface (22, 32) of the lateral portion (20, 30) has an angular extension between 60 and 120.

5. The guide element according to claim 1, wherein said constraint means comprise a front flap (23, 33) and a rear flap (24, 34), protruding from the inner bearing surface (22, 32), adapted to at least partly respectively overlap on a front face (10a) and a rear face (10b) of the central body (10).

6. The guide element according to claim 1, wherein said constraint means comprise at least one element projecting from the inner bearing surface (22, 32) adapted to be inserted in a slot formed on the outer bearing surface (12, 13) of the central body (10).

7. The guide element according to claim 1, further comprising two lateral portions (20, 30) provided with respective sliding surfaces (21, 31) arranged specular with respect to a plane of symmetry (S) of the guide element.

8. The guide element according to claim 7, wherein the central body (10) has two outer bearing surfaces (12, 13) at least partly cylindrical, the axes of said outer bearing surfaces (12, 13) being coincident.

9. Actuator for controlling a valve which comprises: a glyph element (102) connectable to a valve plug; a pin (106) sliding along a slot (105) of said glyph element; actuating means acting on the pin (106) for rotating the glyph element (102); and a guide element (1), according to claim 1; wherein said guide element (1) is connected to said pin (106) and is housed in the slot (105) slidably in contact with at least one lateral wall (108) of said slot.

10. The guide element according to claim 3, wherein the inner bearing surface (22, 32) of the lateral portion (20, 30) has an angular extension between 60 and 120.

11. The guide element according to claim 2, further comprising two lateral portions (20, 30) provided with respective sliding surfaces (21, 31) arranged specular with respect to a plane of symmetry (S) of the guide element.

12. The guide element according to claim 3, further comprising two lateral portions (20, 30) provided with respective sliding surfaces (21, 31) arranged specular with respect to a plane of symmetry (S) of the guide element.

13. The guide element according to claim 4, further comprising two lateral portions (20, 30) provided with respective sliding surfaces (21, 31) arranged specular with respect to a plane of symmetry (S) of the guide element.

14. The guide element according to claim 5, further comprising two lateral portions (20, 30) provided with respective sliding surfaces (21, 31) arranged specular with respect to a plane of symmetry (S) of the guide element.

15. The guide element according to claim 6, further comprising two lateral portions (20, 30) provided with respective sliding surfaces (21, 31) arranged specular with respect to a plane of symmetry (S) of the guide element.

16. The guide element according to claim 11, wherein the central body (10) has two outer bearing surfaces (12, 13) at least partly cylindrical, the axes of said outer bearing surfaces (12, 13) being coincident.

17. Actuator for controlling a valve which comprises: a guide element (1), according to claim 2, a glyph element (102) connectable to a valve plug; a pin (106) sliding along a slot (105) of said glyph element; actuating means acting on the pin (106) for rotating the glyph element (102); and wherein said guide element (1) is connected to said pin (106) and is housed in the slot (105) slidably in contact with at least one lateral wall (108) of said slot.

18. Actuator for controlling a valve which comprises: a guide element (1), according to claim 3, a glyph element (102) connectable to a valve plug; a pin (106) sliding along a slot (105) of said glyph element; actuating means acting on the pin (106) for rotating the glyph element (102); and wherein said guide element (1) is connected to said pin (106) and is housed in the slot (105) slidably in contact with at least one lateral wall (108) of said slot.

19. Actuator for controlling a valve which comprises: a guide element (1), according to claim 5, a glyph element (102) connectable to a valve plug; a pin (106) sliding along a slot (105) of said glyph element; actuating means acting on the pin (106) for rotating the glyph element (102); and wherein said guide element (1) is connected to said pin (106) and is housed in the slot (105) slidably in contact with at least one lateral wall (108) of said slot.

20. Actuator for controlling a valve which comprises: a guide element (1), according to claim 7, a glyph element (102) connectable to a valve plug; a pin (106) sliding along a slot (105) of said glyph element; actuating means acting on the pin (106) for rotating the glyph element (102); and wherein said guide element (1) is connected to said pin (106) and is housed in the slot (105) slidably in contact with at least one lateral wall (108) of said slot.

Description

(1) Further characteristics and advantages of the present invention will become more apparent from the description of an example of a preferred, but not exclusive, embodiment of a guide element of a pin in a glyph, as illustrated in the accompanying drawings, wherein:

(2) FIG. 1 schematically represents a portion of a prior art actuator;

(3) FIG. 2 is a perspective view of the guide element according to the invention;

(4) FIG. 3 is an exploded view of the guide element according to the invention;

(5) FIG. 4 is a cross sectional view of the guide element of FIG. 2;

(6) FIG. 5 is a top view of the guide element of FIG. 2;

(7) FIG. 6 is a perspective view of an actuator provided with the guide element according to the invention;

(8) FIG. 7 is a sectional view according to the line A-A of the actuator of FIG. 6.

(9) With reference to the accompanying figures, the guide element, indicated as a whole with 1, comprises a central body 10, a first lateral portion 20 and a second lateral portion 30.

(10) The lateral portions 20, 30 are separated from the central body 10 and can be placed next to it to form the assembly of the guide element 1.

(11) When the central body 10 and the lateral portions 20, 30 are joined to one another, the guide element 1 has a substantially parallelepiped shape.

(12) In a variant, not shown, the lateral portions 20, 30 can be connected to the central body so that they can move or rotate with respect thereto.

(13) According to the invention, the lateral portions can be more than two in number.

(14) For example, on each side of the central body 10 there can be positioned a plurality of side-by-side lateral portions, which partly or fully cover the length of the central body 10.

(15) In practice, each lateral portion 20, 30 can be a single element or divided into a plurality of separate elements.

(16) The central body 10 is defined by a front face 10a, a rear face 10b, lateral walls 10c, 10d, an upper face 10e and a lower face 10f.

(17) In the central body 10 there is formed a seat 11, typically cylindrical, adapted to house a pin P (FIGS. 6, 7) of a glyph mechanism, better described below.

(18) This seat 11 extends vertically along an axis Z and preferably passes through the entire height of the body 10.

(19) At the lateral walls 10c, 10d thereof, the central body 10 respectively has a first outer bearing surface 12 and a second outer bearing surface 13. These outer bearing surfaces 12, 13 are at least partly cylindrical.

(20) The term at least partly cylindrical surface is intended as a surface defined by the projection along an axis of a circular arc, where this circular arc can have an amplitude equal to or less than 360.

(21) According to a preferred variant of the invention, the two outer bearing surfaces 12, 13 share the same axis X.

(22) This axis X is arranged parallel to the sliding direction of the guide element in the slot of the glyph mechanism.

(23) Preferably, the outer bearing surfaces 12, 13 are specular with respect to a plane of symmetry S of the central body 10, passing through the aforesaid axis X.

(24) These outer bearing surfaces 12, 13 can extend along the axis X only for a portion of the central body 10 or, as in the preferred variant, for the whole of its length.

(25) The lateral portions 20, 30 respectively comprise a front face 20a, 30a, a rear face 20b, 30b, lateral faces 20c, 20d, 30c, 30d, an upper face 20e, 30e and a lower face 20f, 30f.

(26) On the outer lateral faces 20d, 30d there are formed respective flat sliding surfaces 21, 31, adapted to slide in contact with respective lateral walls of the slot of the glyph mechanism.

(27) For this purpose, the lateral portions 20, 30 are preferably made of a metal with low friction coefficient, such as brass, bronze, or alloys thereof.

(28) Alternatively, the lateral portions can be made of different metals and provided with a coating or with an insert made of synthetic material (such as PTFE or its derivatives) positioned at the sliding surface 21, 31.

(29) The central body 10 can be made of steel, or can also be brass, bronze or the like, just as the lateral portions 20, 30.

(30) The lateral portions 20, 30 are joined to the central body 10 at the inner lateral faces 20c, 30c.

(31) On the inner face 20c of the first lateral portion 20 there is formed a first inner bearing surface 22; on the inner face 30c of the second lateral portion 30 there is formed a second inner bearing surface 32.

(32) The inner bearing surfaces 22, 32 are complementary to the respective outer bearing surfaces 12, 13, i.e. they have the same radius of curvature.

(33) When the inner bearing surfaces 22, 32 are in contact with the outer bearing surfaces 12, 13, they all share the same axis X.

(34) As already mentioned, this characteristic allows the central body 10 to rotate freely with respect to the lateral portions 20, 30 about the axis X.

(35) During rotation, the inner 22, 32 and outer 12, 13 bearing surfaces slide in contact with each other.

(36) Preferably, the angular extension of the inner bearing surfaces 22, 32 of the lateral portions 20, 30 can vary as a function of the dimensions of the guide element, but is typically between 60 and 120.

(37) The angular extension of the outer bearing surfaces 12, 13 is greater with respect to that of the inner bearing surfaces 22, 23. In this way, when the lateral portions 20 rotate about the axis X with respect to the central body 10, the inner bearing surfaces can remain completely overlapped on the respective outer bearing surfaces 12, 13.

(38) For example, the angular extension of the outer bearing surfaces 12, 13 is between 100 and 150.

(39) According to the invention, the guide element is provided with constraint means adapted to block translation of the lateral portions 20, 30 along the axis X with respect to the central body 10.

(40) In a preferred embodiment, said constraint means comprise front flaps 23, 33 and rear flaps 24, 34, which protrude beyond the inner bearing surfaces 22, 32.

(41) These flaps 23, 33, 24, 34 are structured so as to at least partly overlap on the front face 10a and on the rear face 10b of the central body 10.

(42) In a variant of the invention (not shown in the figure), these constraint means can comprise at least one element projecting from the inner bearing surfaces 20, 30 adapted to slide in a vertical slot formed on the outer bearing surfaces 12, 13 of the central body 10.

(43) Operation of the guide element 1 will now be described with reference to FIGS. 6 and 7, which show a part of an actuator 100 for controlling butterfly valves, ball valves or the like.

(44) The actuator 100 comprises a case 101 in which there is housed a glyph mechanism, indicated as a whole with 102.

(45) The glyph mechanism 102 comprises a sleeve 103 connectable directly or indirectly to a valve plug (not shown in the figure).

(46) The sleeve 103 is integral with a pair of parallel plates 104 in each of which there is formed a slot 105. The two slots 105 of the two plates are overlapped and aligned with each other.

(47) A pin 106 is inserted between the two plates 104 with its ends at the slots 105.

(48) Each end of the pin is supported in the slot 105 by a guide element 1 according to the invention.

(49) More in detail, the ends of the pin 106 is inserted in the seat 11 of the central body 10 of the guide element. The lateral portions 20, 30 are substantially in contact with the lateral walls 108 of the slot 105.

(50) On the pin 106 there acts a rod 107 connected to hydraulic, mechanical, or mixed, actuator means, not shown in the figure.

(51) The actuators alternatively generate forces F1 or F2 respectively for closing and opening the valve.

(52) As already mentioned, these forces tend to bend the pin 106 which takes an arched shape.

(53) Following bending, the central body 10 is rotated by the end of the pin 106.

(54) Therefore, the central body 10 can rotate with respect to the lateral portions 20, 30, which maintain their position.

(55) The guide element can thus slide along the slot while the sliding surfaces 21, 31 of the lateral portions are perfectly parallel and completely in contact with the respective lateral walls of the slot 105.

(56) As will be apparent, the guide element 1 of the present invention fulfils the intended objects.

(57) Thanks to the relative rotation between the central body and the lateral portions, these are never influenced by bending of the pin of the glyph, even in high deformation conditions.

(58) This allows the lateral portions to slide in contact with the lateral walls of the glyph at all times, obtaining uniform wear of both the surfaces.

(59) In this way, it is possible to substantially reduce costs related to replacement of the guide elements, which is less frequent, and costs related to inefficiencies that require operations to be performed on a system.

(60) The guide element of the invention also has a simple structure, which contributes to limiting manufacturing and implementation costs.

(61) The invention has been described for illustrative and non-limiting purposes according to some preferred embodiments thereof. Those skilled in the art may find numerous other embodiments and variants, all falling within the scope of protection of the claims below.