Valves and valve actuation – Fluid actuated or retarded – Dashpot or fluid controlled retarder or timer
Patent
1989-10-23
1990-08-07
Walton, George L.
Valves and valve actuation
Fluid actuated or retarded
Dashpot or fluid controlled retarder or timer
74 25, 74 8915, 744248VA, 188268, 251229, 251264, F16F 930, F16K 4700
Patent
active
049461311
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
The invention relates to an arrangement for damping linear movements for use on a safety valve.
A damping arrangement of this type is described in FR-A No. 2 389 047.
In the latter, two cup-shaped damping parts, which together define a working gap filled with a viscous medium, have a fixed, predetermined axial position.
If one were to use a damping arrangement of this type on a safety valve, then the damping would not be satisfactory, since the damping comes into action reliably on the one hand already at very small opening displacements of the closure part, irrespective of manufacturing tolerances, which result for example from the machining of the sealing surfaces. Also, in safety valves of this type, the force acting on the valve spindle also varies very considerably depending on the opening displacement and the known damping arrangement thus cannot damp oscillations, which occur in the immediate vicinity of the closing position, as well as other oscillations which are set up around a partly open position.
The present invention therefore intends to develop an arrangement for damping linear movements so that the damping characteristics can be adjusted precisely in a simple manner.
This object is achieved according to the invention by a damping arrangement C.
Advantageous developments of the invention are described in the Sub-claims.
In another damping arrangement, the value of the displacement-independent component of the damping can be adjusted in a very simple manner. One can thus adjust the damping properties of the safety valve easily at the installation point taking into consideration the lengths of the pipe sections connected to the safety valve at the inlet side and the outlet side.
In a damping arrangement according to another embodiment, a small displacement-dependent component of the damping can be adjusted, this component being progressive or degressive according to the pitch of the support-screw coupling.
The development of the invention according to another embodiment is an advantage with regard to the lowest possible abrasive nature of the viscous medium.
The invention will be described in detail hereafter by means of embodiments, referring to the drawings, in which:
FIG. 1 is an axial section through a damping arrangement for a valve spindle operating with a viscous medium; and
FIG. 2 is a similar sectional view to FIG. 1, in which a modified damping arrangement is illustrated.
FIG. 1 shows the upper end of a valve spindle 10, which is provided with a threaded section 12. The valve spindle is guided on a valve housing by way of sliding packings (which are not shown in detail) and at its lower end not shown in the drawing supports a closure member, which co-operates with a valve seat likewise not shown.
Of the valve housing, only an upper end section of the housing 14 is shown, which receives a damping arrangement acting on the valve spindle 10 and designated generally by the reference numeral 16.
Belonging to the damping arrangement 16 is a lower damping part 18, which comprises a transverse base 20 and two working walls 22, 24 coaxial with respect to the axis of the valve spindle 10.
The base 20 is clamped between two threaded rings 26, 28, whereof the external threads engage in an internal thread 30 of the end section of the housing 14.
Engaging between the working walls 22, 24 in the manner of a comb is a further working wall 32, which is supported by a hub section 34. The components 32 and 34 together form an upper damping part 36.
The damping part 36 is mounted by way of an axial/radial bearing 38 on the end section of the housing 14.
The hub section 34 is provided with an internal thread 40, which co-operates with the threaded section 12 of the valve spindle 10.
The annular space defined by the working walls 22, 24 is filled with a highly viscous silicone grease 42. The latter contains graphite as a filler component or as the exclusive filler. The level of the silicone grease 42 extends above the lower edge of the suspended working wall 32 of the upper damping part 36.
T
REFERENCES:
patent: 957311 (1910-05-01), Davis et al.
patent: 2419372 (1947-04-01), Schneider
patent: 4072163 (1978-02-01), Byrnes
patent: 4139016 (1979-02-01), Byrnes
patent: 4364541 (1982-12-01), Chabat-Courrede et al.
patent: 4402335 (1983-09-01), Kemmler
Philpitt Fred
Sempell AG
Walton George L.
LandOfFree
Arrangement for damping linear movements does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Arrangement for damping linear movements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Arrangement for damping linear movements will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-954598