The screw bar of the fine carving machine is composed of screw, nut and ball bearing, which transforms the rotary motion into the linear motion, or the linear motion into the ideal transmission element of the rotary motion! Due to the small friction resistance, the lead screw is widely used in various industrial equipment and fine instruments. However, some problems will still be encountered when using the machine. Improper handling will lead to failures, which will affect the precision of the machine, and even make the machine stop working.

1. Common faults and corresponding diagnosis and removal methods are introduced as follows:

1. Failure caused by improper control of preload force when adjusting axial clearance

The two - nut ball screw nut basically eliminates axial clearance after adjustment by preloading. But at this time should control the size of the pre-tightening force. If the pre-tightening force is too small, the axial clearance cannot be completely eliminated, and the pre-tightening effect cannot be achieved. If the pre-tightening force is too large, it will increase the no-load torque, thus reducing the transmission efficiency, resulting in the drive motor heating and overload alarm. The way to remove such faults is to re-adjust the prestressing force as required so that the gap can be eliminated and the prestressing force is not large.

2. Failure caused by non-self-locking of ball screw:

Ball screw nut has low friction coefficient and high transmission efficiency, but can not self-lock. Therefore, when the ball screw nut is used for vertical transmission or horizontal high speed and large inertia transmission, the spindle box may slide or overshoot to prevent sudden power failure. The brake device must be considered in the transmission chain, otherwise, abnormal failure will be caused by the inertia movement of the moving parts, which will seriously damage the parts of the machine. The commonly used braking methods include overrunning clutch, electromagnetic friction clutch or servo drive motor with braking device.

3. The noise of ball screw nut in driving process is a high-precision transmission element. The reason for the noise in work is that there are some defects in the assembly and adjustment process, or the daily inspection and maintenance is not in place. If the fasteners are loose, the bearing gland is not in place, the supporting bearing or screw nut is damaged and the lubrication is not good. In order to reduce the occurrence of such faults, it is necessary to strengthen the daily inspection and maintenance of the feeding drive chain at ordinary times, tighten the loose parts in a timely manner, adjust the feeding drive chain in a timely manner through the detection of the processed parts, and check whether the lubrication system is smooth.

2. Ball screw and screw are precision parts. The following points should be noted when using:

(1) please confirm the state of lubrication before use. If the lubrication is not good, will lose the function of ball screw in a short time.

(2) please use directly when applying grease. However, in the course of operation, if the surface of the grease is coated with dust or powder, please clean it with clean white kerosene and reapply the same new grease as the original grease before using it. Mixed use of grease of different properties should be avoided.

(3) as the lubricant, it is recommended to wipe the old lubricant on the product and then re-apply the new lubricant when the dirt is obvious. After this, the grease should be inspected regularly and the lubricant should be replaced for a period of one year in general, provided that an appropriate interval period is set according to the use environment.