Vacuum valve
A vacuum valve for high/ultra-high vacuum systems includes a valve housing defining a passage connecting a first and a second opening of the housing. A valve body and a complementary seat is disposed in the passage, the valve body and/or the seat including a seal and the valve body being movable in a linear axial direction along between an open position and a closed position. The valve body cooperates with the seat in the closed position so as to close the first opening gas-tightly. An electromechanical actuation unit for actuating the valve body includes an electric motor and a mechanical conversion unit with an input portion drivingly connected to the motor and an output portion drivingly connected to the valve body. The conversion unit converts a rotational output of the electrical motor into a linear movement of an output portion to move the valve body in the axial direction.
1 . A method for operating a vacuum valve, the vacuum valve comprising
a valve housing defining a passage connecting a first and a second opening of the valve housing,
a valve body and a complementary seat disposed in the passage, the valve body and/or the seat comprising a seal member and the valve body being movable in a linear axial direction between an open position and a closed position, wherein the valve body cooperates with the seat in the closed position so as to close the first opening gas-tightly, and
an electromechanical actuation unit for actuating the valve body, the actuation unit comprising an electric motor and a mechanical conversion unit with an input portion drivingly connected with the electric motor and an output portion drivingly connected with the valve body, wherein the mechanical conversion unit converts a rotational output of the electrical motor into a linear movement of the output portion to move the valve body in the axial direction,
the method comprising:
operating the electric motor during a movement of the valve body into the closed position such that a velocity of the valve body is reduced before and/or during a contact between the valve body and the seat,
wherein the electric motor is operated in the closed position of the valve body such that a force acting on the seal member does not fall under a predetermined threshold value, and
wherein the electric motor is operated in the closed position of the valve body such that the force acting on the seal member does not fall under the predetermined threshold value.
2 . The method according to claim 1 , wherein the electric motor is operated such that the movement of the valve body from the open to the closed position takes longer than the movement of the valve body from the closed to the open position.
3 . The method according to claim 1 , wherein the electric motor is operated such that a compression of the seal member during the movement of the valve body into the closed position takes longer than the decompression of the seal member during the movement of the valve body out of the closed position.
4 . The method according to claim 1 , wherein the operating the electric motor in the closed position includes monitoring current applied to the electric motor and adapting the current such that the force acting on the seal member does not fall under the predetermined threshold value.