And in these bearings here are shaft encoders, and they sense that the rotation that the outer housing makes in order to keep this thing pointing at the same direction.
在这些轴承中，有轴角编码器，它们感受到了外面的框的转动，来保持这个东西，指向相同的方向。
2
These use a central shaft with sliding vanes inside a housing of decreasing radius.
这些使用一根中心的轴由于在一个减少半径的住房里面滑动风向标。
3
The bearings are generally installed with a small axial clearance in order to compensate for length variations of shaft and housing.