EP0393111B1

EP0393111B1 - Exhaust valve

Info

Publication number: EP0393111B1
Application number: EP89900362A
Authority: EP
Inventors: Sven Erik Roland Olsson
Original assignee: Kockums AB
Current assignee: Saab Kockums AB
Priority date: 1987-12-21
Filing date: 1988-12-20
Publication date: 1992-03-25
Anticipated expiration: 2008-12-20
Also published as: SE8705084D0; AU2791589A; DE3869622D1; AU624348B2; ES2016430A6; WO1989005901A1; SE8705084L; EP0393111A1; SE459600B

Abstract

Exhaust valve comprising a valve housing (1), a valve seat (4) formed therein, and a valve element (5) supported by movable supporting means (6) for moving the valve element (5) into and out of sealing engagement with the valve seat (4). The valve element (5) is supported for movement along an axis and rotation about said axis with respect to said supporting means (6) between two end positions by yieldable means (10, 11), for imparting to the valve element (5) a rotational movement about said axis simultaneously with movement thereof along said axis, so as to impart to the valve element (5) when engaged with the valve seat (4) a rotational movement relative to the valve seat (4) after the valve element (5) having been engaged with the valve seat (4) and before having been lifted therefrom.

Description

The present invention relates to exhaust valves comprising a valve housing, a valve seat formed therein and a valve element supported by movable supporting means for moving the valve element into and out of sealing contact with the valve seat. The invention particularly relates to exhaust valves of this kind for use in the exhaust duct from the engine of a submarine.
One problem inherent in exhaust valves is that due to the flow of usually hot exhaust gases through the valve, dust particles and impurities tend to deposit on the sealing surfaces of the valve element and the valve seat, and this gradially reduces the sealing effect of the valve. In order to reduce the amount of remaining deposits on the sealing surfaces of the valve element and on the valve seat, it is previously known in exhaust valves used in internal combustion engines to impart to the valve element a certain small rotary motion in connection with opening and closing of the valve, so that each time the valve element moves into contact with the seat it has been rotated a small angle in relation to the valve seat. Even if this to a certain extent may have a cleaning effect it does not provide such grinding effect as obtained by relative movement between the sealing surfaces, and as required in order to effciently remove impurities which have adhered to said sealing surfaces. This may be one of the reasons why the method mentioned above has not been practised in exhaust valves of the kind used in the exhaust ducts of engines of submarines. When using exhaust valves of this kind it has proved necessary to dismount the valve regularly at relatively short intervals and to carry out grinding of the sealing surfaces between the valve element and the valve seat by means of special grinding tools.
EP-A-0 226 157 discloses a valve used in lines for liquids containing particles, said valve comprising a valve housing, a valve seat formed therein and a valve element movable in said housing between open position and closed position in engagement with the valve seat. The valve element is connected to a rod which is axially displaceable in a cylindrical sleeve for moving the valve element between open and closed positions. By means of a drive motor said rod may be rotated to and fro for transmitting said rotary motion to the valve element when the valve elment is in its closed position.
One object of the present invention is to provide an exhaust valve of the kind mentioned initially, in which an efficient gringing action on the sealing surfaces between valve element and valve seat is obtained each time the valve is opened and closed, said grinding action being obtained by relative movement between the sealing surfaces, said surfaces simultaneously being urged towards each other by a predetermined pressure force. Another object of the invention is to provide an exhaust valve including means which automatically provides said grinding action and which is simple with respect to its design and which without difficulty may be included into the supporting device used for moving the valve element into and out of engagement with the valve seat.
The objects mentioned above are obtained by means of a design in accordance with the appended claims.
The invention will be described below with reference to an embodiment of an exhaust valve of the kind used in the exhaust duct from the engine of a submarine and which is illustrated on the appended drawing, on which

fig 1 is a longitudinal section through an exhaust valve in accordance with the invention, and
fig 2 is a section taken as indicated by I - I in fig 1.

The exhaust valve illustrated in the figures include a substantially spherical valve housing 1 provided with two pipe sockets 2 and 3 respectively connected with the valve housing and extending co- axially with respect to each other. The pipe socket 2 extends a certain distance into the valve housing and terminates into a circular valve seat 4 cooperating with a valve disk 5 which may be brought into engagement with the valve seat. By means of a supporting device 6 which is swingably mounted in the valve housing 1, the valve disk 5 may be swung between closed position as indicated by unbroken lines in fig 1 and open position as indicated by dash-and-dot lines in fig 1. This supporting device 6 includes a shaft 7 rotatably supported in the valve housing 1, said shaft extending within the valve housing 1, through the walls thereof and terminates outside the valve housing. At least one end of said shaft 7 is connected to hydraulic, pneumatic, electrical or other power means, by means of which shaft 7 may be rotated between two angular positions. Shaft 7 is disposed sideways and above the valve seat 4 and extends in parallel with a plane through the upper edge of the valve seat 4. Inside the valve housing 1 the shaft 7 is rigidly connected with a hub 8 from which an arm 9 extends in the direction towards the valve seat. Supported at the free end of arm 9 is a preferably cylindrical sleeve 10 of annular cross section, said sleeve extending coaxially with the pipe socket 2. A rod 11 of circular cross section is axially displacable in said sleeve 10 and extends through end walls 12, 13 of said sleeve. At the end portion of rod 11 extending towards the valve disk 5, rod 11 is connected to the valve disk 5 so that a rotational movement of rod 11 about its own axis is transmitted to the valve disk 5, thus imparting to the valve disk a corresponding rotational movement. As shown in fig 1 the connection between rod 11 and valve disk 5 is obtained by means of a spherical, ball-like member 14 formed at the end of rod 11, said spherical member being provided with two pins 15 extending from the spherical member 14 in opposite directions. The spherical member or ball 14 including the pins 15 is jounaled in the hub 5A of the valve disk 5 so that valve disk 5 will have a certain freedom of movement with respect to the rod 11, but so that when rod 11 is being rotated about its own axis, a corresponding rotational movement is imparted to the valve disk. Inside sleeve 10 the rod 11 is provided with a washer 16, rigidly connected to the rod. Disposed between the washer 16 and the upper end wall 13 of sleeve 10 is a compression spring 17 which continuously exerts a pressure force on the washer and thus on rod 11 in the direction towards the valve seat. The sleeve 10 is provided with stops 18 disposed on the inner surface of the sleeve above the washer 16, said stops limiting the movement of washer 16 in the sleeve 10 between the bottom 12 thereof and said stop 18. Washer 16 is further provided with grooves, which cooperate with a corresponding number of rims 19 which are rigidly connected with sleeve 10 on the inside thereof between the bottom 12 of the sleeve and said stops 18. The rims 19 extend under a certain inclination with respect to the direction of the central axis of rod 11 and sleeve 10 respectively, so that when rod 11 is being displaced in the axial direction of the sleeve 10, a rotational movement about its own axis is imparted to rod 11 by means of washer 16. As mentioned previsously the rotational movement is transmitted to the valve disk 5. Axial displacement of rod 11 thus imparts a rotational movement to the valve disk corresponding to the rotational movement of rod 11.
When opening the valve, which is shown in its closed position in fig 1, the arm 9 is made to swing counter-clockwise by rotating shaft 7 counter clockwise. During the first sequence of said swinging movement the valve disk 5 will remain in contact with the seat 4 under the influence of the force of the compression spring 17, due to the fact that spring 17 expands. Due to this rod 11 is displaced axially with respect to the sleeve, a rotational movement at the same time being imparted to rod 11 via rims 19 and washer 16. This rotational movement is transmitted to the valve disk which thus is caused to carry out a corresponding rotational movement. During this rotational movement the valve disk is still urged by pressure force towards the valve seat under the influence of the force exerted by the spring. Due to this rotational movement, the valve disk performs a periferal sliding movement along the valve seat, thus exerting a grinding action on the valve seat, and due to this the valve seat is kept free from impurities. The swinging movement of arm 9 is continued until the fully open position of the valve has been reached, as indicated by dash-and-dot lines in fig 1.
When closing the valve arm 9 is made to swing in the opposite direction, i e clockwise. Under the influence of the force from spring 17 the washer 16 in the sleeve 10 is kept in abutment against the bottom wall 12 of the sleeve 10. When the valve disk 5 during continued swinging movement has ben swung into engagement with valve seat 4, continued swinging movement of arm 9 results in that rod 11 is displaced with respect to the sleeve 10, at the same time compressing spring 17. Via rims 19 and washer 16 a rotational movement is imparted to the rod 11 and thus also to the valve disk 5. During this rotational movement the valve disk 5 is in engagement with the valve seat 4, thus exerting a grinding action on the seat.

Claims

1. Exhaust valve comprising a valve housing (1), a valve seat (4) formed therein and a valve elment (5) movable in said housing between open and closed positions, a supporting device (6) movable in said housing (1) and supporting the valve element (5) for movement thereof between said open and closed positions, the supporting device (6) comprising a preferably cylindrical sleeve (10) and a rod (11) which is axially displaceable in said sleeve between upper and lower positions, said rod (11) extending out of the sleeve towards the valve element (5) and being connected at its protruding end with the valve element (5) for transmitting axial as well as rotational movement of said rod to the valve element (5), said rod (11) being continuously urged towards its lower end position in the sleeve (10), characterized in that said rod (11) and sleeve (10) are provided with mutually cooperating rims and grooves adapted to impart a rotational movement to the rod (11) during axial displacement of said rod (11) in said sleeve, so as to impart to the valve element (5) a rotational movement relative to the valve seat before the valve element during opening is lifted from the valve seat and after the valve element during closing has been brought into engagement with the valve seat.

2. Exhaust valve as claimed in claim 1, characterized in that a washer (16) is rigidly connected to said rod (11), a compression spring (17) being disposed between said washer (16) and an upper end wall (13) in said sleeve (10), said compression spring (17) continuously excerting a pressure force on said rod in a direction towards the valve seat, said washer (16) further being provided with grooves cooperating with rims disposed on the inner surface of the sleeve and extending under an inclination with respect to the direction of the central axis of the rod and the sleeve so as to impart to said rod and to said valve element a rotational movement when the rod is being displaced in the axial direction in the sleeve.