Metrology apparatus

摘要

A metrology apparatus including a body and a first member rotatable relative to the body about a first axis of rotation, said first axis being defined by first bearing and a first motor for actuating rotation of the first member relative to the body about the first axis of rotation. A surface sensing device is attachable to the first member such that the surface sensing device can move with the first member, relative to the body. The first motor may include a first magnet and at least one metal coil spaced apart along the first axis and mounted such that the first magnet and the at least one metal coil are moveable relative to one another.

主权项

1. A metrology apparatus comprising:
a body and a member mounted to the body by mechanical bearing assemblies such that the member is rotatable relative to the body about an axis of rotation; a motor for actuating rotation of the member relative to the body about the axis of rotation; wherein a surface sensing device is attachable to the member such that the surface sensing device rotates with the rotation of the member, relative to the body; wherein the motor comprises a magnet and at least one metal coil spaced apart along the axis and mounted such that the magnet and the at least one metal coil are moveable relative to one another; and wherein the motor is arranged such that when it actuates rotation of the member relative to the body, substantially no radial forces from the motor act on the mechanical bearing assemblies such that the location of the axis remains substantially fixed.