指出下图中转向器的名称，图中各标号所代表的零件名称。<br /> <img src="https://nimg.ppkao.com/2019-04/tangxixi/2019041110564752043.jpg?sign=3b3fc8db550d0ddd8c1f91f89cbcd0bc&t=62d55f7d" />