机电技术专业英语课件作者徐起贺张庆良pataalessonSixteen.pptVIP

尚辅网 / 机电技术专业英语 Lesson Sixteen Text The milling machine is a machine that removes metal from the work with a revolving milling cutter as the work is fed against it1. The milling cutter is mounted on an arbor where it is held in place by spacers or bushings. The arbor is fixed in the spindle with one end, while the other end of the arbor rotates in the bearing mounted on the arbor yoke2. The milling cutters are generally made from high speed steel and are available in different sizes and shapes. There are such kinds of milling cutters as cylindrical cutters, end milling cutters, side and face cutters, slitting saw, etc (Figure.A.9). These cutters may differ in the direction of their operation, i.e. they may cut revolving either clockwise or counterclockwise. Milling Machines Lesson Sixteen Regular or irregular shaped work may be produced on a milling machine, designs varying according to the particular class of work wanted. According to the position of the spindle, the milling machines may be divided into two groups of vertical spindle milling machines and horizontal spindle milling machines (Figure.A.10). Milling machines may be grouped into various classes according the variation in general design as the column and knee type, the manufacturing types, and the planner type of milling machine3. According to table design, the milling machines may be classified as universal and plain milling machines. The most important parts of the milling machine are:①starting levers; ②spindle; ③column; ④knee; ⑤elevating screw; ⑥table; ⑦index head; ⑧speed levers; ⑨feed levers; ⑩table movement levers; foot stock; arbor yoke. Lesson Sixteen Lesson Sixteen The spindle of the milling machine is driven by an electric motor through a train of gears mounted in the column. The table of the plain milling machine may travel only at right angles to the spindle while the universal milling is provided with a table that may be swiveled on the transverse