As shown in Fig. A and B are two identical gears, the A is fixed and can not move. If the B gear moves around the A gear for half a week and reaches the position of C in the figure, then the B toothThe vertical upward arrow indicated on the wheel is "("). [see Fig. http://zhidao.baidu /question/91498260.html]A vertical upward, B vertical downwardC level left, D horizontal, right
I see. You may be confused by the gears that occlude each other. For example, consider the possibility of turning 90 degrees from the top. Figure two position of purple dotted line connecting should be mutually engaged together, so around 90 degrees, the arrow indicates the position should be above A, the arrow down, B turned 90 degrees, the direction of the arrow to turn 180 degrees, so B to turn 90 degrees, the arrow will continue to turn 180 degrees to become. I wonder if I understand it.
Then the stroke from the B position to the C position is pi *2r, so the travel angle of the gear B is pi *2r/2=2 PI, that is, the gear B turns a circle, so the arrow points to the vertical upward
Isn't there an answer to the link you gave?The answer is A. When the A is fixed, only B rotates. Obviously, B rotates at the center of the A, assuming that the gear tooth diameter is R
