DE680573C - Overflow valve, especially for rotary lobe fluid pumps - Google Patents

Description

Overflow valve, especially for rotary lobe pumps Es it is known to have an overflow valve in pumps or in their pressure chamber or pressure line to be arranged with a spring-loaded shut-off piston, which has the task of ... in the event of overpressure or if the flow rate is not required, this into the suction chamber the pump or its. Returned suction container. If all of it or just the greater part of the flow must flow through this valve, a very considerable pressure increase, since the valve piston is lifted very high in this case must become; which in turn results in a considerable increase in pressure in the valve spring Has. This results in z. B. an overload of the drive motor. and a response of the engine fuses with subsequent malfunctions. Man. can probably go through a sufficiently long valve spring keep the pressure rise within acceptable limits; but becomes the spring and with it the spring housing and the required adjustment device for the spring in relation to the valve itself quite disproportionately long: according to the invention these aforementioned shortcomings are eliminated in that -the shut-off piston over its valve seat a known per se, which increases the effective valve seat area Has a circular ring surface and this piston turns into an exchangeable, cylindrical Annular body with through openings that increase greatly with increasing Il, piston stroke leads, whereby the dynamic pressure influencing the piston ring surface is caused by another known throttle member is also influenced.

Fig. I shows an embodiment, wherein in the housing 2 and 3 a valve with shut-off piston 5 is seated, which is loaded in an adjustable manner by a spring will. ,.

The valve is shown in the rest position and through the connection i with the pressure chamber of the pump in connection.

If overpressure occurs, the lower part of the valve cone will grow acted upon - and thereby raised the valve cone. Hydraulic fluid penetrates on it in the annular .raum 9 and acts on the circular ring surface 6, whereby that of the spring . counteracting pressure is increased and. a larger stroke of the valve cone can be achieved is. In the housing is an annular body 4 with one or more throttle openings 8 provided. These openings 8 have a shape shown in FIG. Through this is achieved, -that the back pressure in the storage space 9 in: every height of the valve cone has a size corresponding to the respective spring pressure. The through the openings 8 - outflowing liquid goes through the line io and -12 to the suction chamber of the pump or their suction container back. To influence the dynamic pressure 9 afterwards, to be able to is. a well-known throttle. Organ 11 built into the drain line. Subsequent influencing may be necessary if a machine system is started up with cold oil, the oil later warms up in the operating state and so that its viscosity changes. The ring-shaped body B is interchangeable, - by an existing overflow valve size for different viscous liquids and pressures to be easily adjusted for different systems.

Claims (1)

PATENTANSPRUGFi overflow valve, especially for rotary lobe pumps, with a spring-loaded shut-off piston, characterized in that the shut-off piston (5) a known per se above its valve seat. the effective valve seat area enlarging circular ring area (6) and this piston is in an exchangeable, cylindrical ring body (4) which increases sharply with increasing piston stroke Passages (8) leads, __ where the influencing the circular ring area Back pressure by a further throttle element (t i), which is known per se, in addition being affected.