| 摘要 |
<p>A handheld pneumatic medical device, such as a dentist handpiece, is provided for rotating a bur about an axis. Importantly, the device utilizes the boundary layer effect to transfer energy from the fluid flow to rotation of the bur. As a result, the device is operated without creating high decibel noise. Structurally, the device includes a housing defining a chamber, and a hub mounted for rotation in the chamber. When engaged with the hub, the bur passes through a distal aperture in the housing. The housing is further provided with a port for introducing a fluid into the chamber substantially tangential to the axis. Also, the device includes disks connected directly or indirectly to the hub and substantially perpendicular to the axis. Operationally, boundary layer effect forces between the fluid flow and the disks cause the hub and the bur to rotate about the axis.</p> |
