Precautions for installation and debugging of mechanical parts of CNC machine tools

1. Precautions for the installation and debugging of the spindle bearing (1) When installing, debugging and assembling a single bearing, try to make the eccentricity of the positioning inner hole of the spindle and the spindle shaft diameter and the eccentricity of the inner ring of the bearing and the raceway close, and make the direction opposite , This can reduce the amount of eccentricity after assembly. (2) Installation and debugging of the two bearings When installing the two-supported spindle bearing, the eccentricity direction of the front and rear support bearings should be the same, and the eccentricity should be appropriately selected. The accuracy of the front bearing should be one level higher than that of the rear bearing, so that the eccentricity of the front end positioning surface of the main shaft component after assembly is small. When disassembling the spindle bearing in the maintenance machine tool, because the original manufacturer has adjusted the eccentric position of the bearing, it is necessary to mark the position in the circumferential direction before disassembly. After reassembly, the original relative position of the bearing and the spindle remains unchanged to reduce the impact on the spindle components. . When assembling the bearing with interference fit, hot or cold mounting process is required for installation. Don't knock it with force, so as not to damage the bearing during the installation process and affect the performance of the machine tool. 2. Precautions for installation and debugging of ball screw nut pair The ball screw nut pair is only used to bear axial load. Radial force and bending moment will cause the ball screw pair to generate additional surface contact stress and other undesirable loads, which may cause the screw to be damaged. Therefore, when the ball screw nut pair is installed on the machine tool, attention should be paid to the following: (1) The ball nut should move within the effective stroke. Limits must be configured at both ends of the stroke to prevent the nut from overtraveling the screw shaft and causing the ball to fall off. (2) Due to the high transmission efficiency of the ball screw nut pair, it cannot be self-locking. When used for vertical transmission, if the weight of the component is not balanced, it is necessary to prevent the reverse transmission caused by the weight of the component after the transmission stops or the motor loses power. , The method to prevent reverse transmission is available: worm gear drive, electric brake, etc. (3) The axis of the lead screw must be parallel to the axis of the matching guide rail. The center of the bearing seat at both ends of the machine and the center of the nut seat must be in line with three points. (4) When installing the ball screw nut pair to the machine tool, do not remove the nut from the screw shaft. If it is necessary to remove it, use an auxiliary sleeve, otherwise the balls may fall off during loading and unloading. (5) When inserting the nut into the mounting hole of the nut base, avoid impact and eccentricity. (6) In order to prevent chips from entering and wearing the ball screw nut pair, protective devices such as wrinkle protection cover, spiral steel belt protection cover, etc. can be installed to completely protect the screw shaft. In addition, dustproof rings can be added at both ends of the screw nut when there is a lot of dust. 3. Precautions for installation and debugging of linear rolling guide (1) Handle with care during installation to avoid bumps that affect the linear accuracy of the guide. (2) It is not allowed to detach the slider from the guide rail or push it back beyond the stroke. If you need to remove the slider due to difficulty in installation, you need to use the guide rail. (3) When the linear rolling guide is used in pairs, it is divided into main and auxiliary guide rail pairs. First install the main guide rail pair. Set the reference side of the guide rail and the reference side of the installation step closely, tighten the mounting bolts, and then use the main guide rail pair. As a benchmark, align and install the auxiliary rail pair. Finding refers to the parallelism and flatness of the two guide rail pairs. , Tighten the fastening bolts of the slider in turn.