Steps：

1. Draw lines to determine the position of the center and top edge of the circle
2. Draw a circle with a radius of 16, this requires pressing shift+right-click to bring up the object snap menu,
   2.1 In the capture menu, select from and set the center of the circle at a distance of 40 from the endpoint.
3. Draw concentric circles with radii of 12 and 25 with the endpoint of the line as the center of the circle
4. Draw a line with an inclination of 105 degrees with the endpoint of the line as the vertex,
5. Mirror the two concentric circles at the bottom.
   6 use the Circle TTR command to draw circles with radii of 100 and 80 and trim them.
6. Starting from the right endpoint of the upper circle, draw a vertical line that intersects with the top line
7. Fillet with radii of 18 and 15 respectively
8. Trim and mirror the objects, then trim the drawing again and add annotations