【正文】 . Horizontal spindle box can be used as a mobile machine can process diameter φ95 ~ φ385mm any kind between the screw specifications. Φ95 ~ φ385mm processing because of the diameter of the screw, causing the front surface and the tool spindle rotation the distance between the center line of the margin is too large, the actual application in the design specifications of the machine into two, a φ95 ~ φ205mm machine screw diameter Another φ180 ~ φ385mm machine screw diameter. Advantages: a variety of tools to adapt to the specifications of the processing screw, each screw specifications need not be provided with the appropriate machine tools. Disadvantage: the structure of machine tools and machine tool assembly of the two kinds of more plex machine tools, machine tools than the cost of two kinds of machine tools before the high. Second, introduce the structure of machine tool spindle The level of machine tool spindle box on the main axis and the base of the vertical axis determines the degree of precision was the precision screw machining, at the same time screw pressor at a speed of thousands of highspeed rotary switch, the accuracy of the screw will be less so that the pressor have a fever, vibration, low efficiency, such as wear and tear situation quickly. Currently available singlescrew machine spindle structure of the program has the following two. The first is: bearing radial clearance is not adjustable spindle structure Before spindle bearing out the use of one pairs of cylindrical roller bearings and thrust ball bearing bination of both, the main use of double row cylindrical roller bearings under radial cutting force, the use of two ball bearings to bear axial thrust cutting force. After the general adoption of the spindle bearings out one pairs of cylindrical roller bearings or a ball bearing to the heart. Main advantages of this structure: the main axis of the processing and assembly of simple, low cost. One disadvantage: because the main axis of the radial bearing clearance can not be adjusted so poor precision spindle. Although the use of bearings and shaft diameter fit to eliminate the radial bearing clearance, but each bearing diameter and radial clearance is not a fixed value, so it is difficult to design and processing to the quasiaxialradial and bearings with bore tolerances. 2 disadvantage: it is very difficult to buy in the market of domestically produced or imported, C, D or P4, P5 class thrust ball bearings, machine tool manufacturing plant monly used alternative to the use of ordinary class bearings, which also affected the accuracy of the enhance spindle. Bearing radial clearance adjustable spindle structure do not apply to the general accuracy of the general machine tools, does not apply to require a higher accuracy of the spindle of machine tools. The second: the radial bearing clearance adjustable spindle structure Before the adoption of a spindle bearing P4 class of double row tapered hole cylindrical roller bearings and a P4class double row ball bearing thrust to the bination of heart. The use of the spindle hole of the double row tapered cylindrical roller bearings under radial cutting force, the use of double row ball bearing thrust to the heart to bear part of the axial and radial cutting force cutting force. Spindle bearings generally used after a P5 class of double row tapered hole cylindrical roller bearings. Double row tapered hole cylindrical roller bearings with inner ring and shaft are tapered 1:12, bearing lock nut with a round led a bearing in the axial displacement of the inner ring bearings and expansion, to reduce or eliminate Bearing radial clearance purposes. Main structure of such advantages: high precision spindle. At the front spindle diameter φ230mm noodle on the end measuring spindle Beat value of . Φ230mm cylindrical spindle at the front end on the radial axis measurement value of Beat . The second structure of the spindle of a precision spindle accuracy than the first about 50% improve. Main disadvantage of this structure: The principal axis of the more plicated process, the spindle assembly also has the experience necessary to make the workers to operate the spindle achieve the desired numerical accuracy. Third, the depth of the tool feed control Required different processing screw diameter spiral groove depth is also different from the depth of the spiral groove mm from dozens to more than 100 millimeters range around the tool into the institutions required to feed the thousands of ring rotation in order to achieve a screw machining . Feed because of the tool in the tool rotating at the same time achieve motion feed, so on a number of general machine tools used in mechanical, electrical control method of depth of cut does not apply to singlescrew machine. Single screw machine tools give agencies into the following different methods can be feed to control the depth of purpose. The first is: friction clutch and electrical switches to control the depth of the tool feed Its principle is to control depth of cut increases the tool cutter feed mechanism increases the load torque so that the tool feeding mechanism of the friction transmission chain slipping clutch, a mechanical linkage concurrent silent trigger electrical switches, optical signal prompted operator, when manual operator to disconnect the tool into the power sector. The advantages of this control method are: the control method is simple and spare parts processing and operational power from the impact of a sudden. Disadvantage are: processing of different diameter screw to adjust the clutch friction discs pressed the preload spring. Material because of the density of each screw, and the hardness of the existence of subtle differences in the degree of cutting tools sharp differences exist, thus the accuracy of this control method was not too accurate, may lead to screw spiral groove depth tolerance is too larg