| 摘要 |
<p>A drive assembly comprising a wall 25 defining a chamber 40 containing a drive assembly component, a port 7 on the wall of the chamber to enable access to the chamber and a removable getter device 4, wherein the getter is exposed within the chamber when the port is closed. Preferably the getter is carried by a port closure element 8. The getter may be sealed within a breachable capsule 6 which is breached by a breaching mechanism when the port is closed, where the breaching mechanism may be a mechanical piercing element or a pressure difference. Preferably there may be a heater carried by the closure element or chamber that is used to activate the getter. A drive assembly with a magnetic field generating device, a method of maintaining an environment, a getter capsule and a chamber port closing element is also claimed.</p> |
