| 摘要 |
A valve assembly comprises a valve opening (4) which can be sealed and un-sealed by movement of a membrane 6; a force generator, such as an electromagnetic force generator comprising a solenoid (20) and anchor (18) arrangement; and a shaft (8) that is operably connected to the membrane (6) and which is movable along a movement axis (C) under the influence of the generated force to move the membrane (6) and thereby regulate the degree of opening of the valve (44). Bearing assemblies (14;16) are provided to procure a magnetic suspension of the shaft (8), permit its movement along the axis (C), and also to optionally procure a magnetic biasing of the shaft (8) in a direction along the axis (C), particularly in the absence of a generated force. <IMAGE> |
