The electric spindle is a key and important component of high -speed machining machines. . This article provides the inspection and preventive maintenance of the electric spindle.
There are many technical indicators and parameters of the electric pins, but many parameters are parameters used by the manufacturer of electric pins for inspection and factory calibration. End users must carry out an inspection and preventive repairs on the electric spindle, and they must determine the appropriate parameters and indicators before being able to carry out repairs and preventive inspections.
1. Technical parameters related to the performance of the electric spindle
Depending on the current state of use and maintenance of the electric spindle and relevant electric electrical electrical bike standards, the main following technical parameters are established: dynamic balance of the electric spindle, mechanical vibration condition of the electric spindle, condition From the carrying envelope of the electric spindle, departure and closure state of the spindle, and power of the electric spindle blade, EM value of the electric spindle (extension of traction rod of the spitting mechanism: the distance Between the end of the stem of the spindle of the spindle rotation is 10.5 mm; Rod of the rod of the rotation end of the spindle is 0.5 mm), axial circular jump of the electric spindle ≤ 0.005 mm, radial circular jump ≤0.02 mm / 300 mm, etc. .
The dynamic balance of the electric spindle refers to the dynamic balance of the electric spindle when it runs at high speed. Damage, zone heating, machining precision and surface treatment.
The state of mechanical vibration of the electric spindle is an assessment of the overall state of mechanical vibration of the electric spindle, including radial and axial vibrations. If the overall state of mechanical vibration of the electric spindle is not good, it will aggravate the wear of the bearings and the heating of the spindle, and will reduce the precision of machining and the quality of treatment of the surface.
The state of the electric spindle bearing envelope is specifically used to assess the treading state of the electric spindle. It mainly determines the degree of wear or damage and the location of the bearing by detecting the low -frequency, medium and high frequency of the bearing vibration signals. Low frequency signals generally represent the wear of the outer ring of the bearing, the medium frequency signals represent the surface of the roll of the bearing of the rolling, and the high frequency signals represent the condition of a single ball.
The set of starting and stopping the pin is generally used to check and measure the vibration state of the 0 spindle at the specified speed and the speed specified at 0, and to measure the peak of resonance of A certain speed or a certain speed range, therefore as if to avoid this during normal treatment.
2. Detection of the electric spindle state
We have carried out continuous monitoring of electric pins using electric vibration testers and acceleration sensors in the company’s high -speed machining center. spindle and bearings. Of the 68 electric pins, 58 electric pins have a lifespan of more than two years, the real operating time of the electric spindle exceeds 4,000 hours and 32 electric pins exceed 6,000 hours.
Before carrying out the detection of the state of the electric spindle and preventive maintenance, there is no means or technical measure to understand and control the state of technical performance of the electric spindle, and it does not Nor is there any relevant technologies to warn and prevent the use of the electric spindle. is used until it is seriously heated, the spindle roller is locked and cannot turn, and is only sent for repair when it is almost in the scrap state. However, the electric spindle was seriously damaged at this time, and the spindle bearings, spindle mechanisms, rotating parts, sealing parts and spindle cone sleeves must all be repaired or replaced. Damage to the joint, etc. Coil and short-circuit coil insulation drops. In this state, the cost of maintenance of the electric spindle is very high, the cycle is very long, the cost of maintenance is generally as high as more than 200,000 yuan and the maintenance cycle is often more than two months. The lifespan of the electric spindle is only 4,000 to 6,000 hours, which is much lower than the spindle manufacturer renovates the lifespan of 6,000 ~ 10,000 hours of electric spindle.
Depending on the parameters and standards determined, detection of the state of the electric spindle is carried out. The results of detection of the electric spindle are presented in figures 1 to 3.
Figure 1 FZ37 pin detection result
Figure 2 jobs30 electric spindle detection result
Figure 3 VMC13120u electric spindle detection
We have changed the practice of using the electric spindle until it is abandoned. technical performance or is just in the red state. The price is low, generally around 100,000 yuan. The first batch of eight electric spindles that have been renovated in this way were used for 7,000 hours. Before the status detection was carried out, and the cost of repair is also considerably reduced from 2016 to 2018, on the basis of the state data of the electric spindle, more than 10 electric pins have been repaired, which saved more 1 million yuan in costs, considerably extending the lifespan of the electric spindle.
3. Preventive maintenance of electric pins
According to the measured data, the electric spindle is regularly maintained and distributed preventive to maintain the electric spindle in good use.
(1) The detection of the strength of the spindle of the electric electric different models and specifications. The pin mechanism, and it is necessary to check carefully because the spindle is drawn. The detection of the strength of the electric spindle spindle is illustrated in Figure 4.
Figure 4 Force detection of the electric spindle blade
(2) Check the geometric accuracy of the electric spindle.
Figure 5 Geometric accuracy of the detection of the electric spindle
(3) Check the state of mechanical vibration, dynamic balance and the starting state of the electric spindle. The machining precision and the quality of the surface treatment will decrease. According to the technical requirements of the electric spindle, the dynamic balance of the electric spindle is adjusted by detecting the dynamic balance of the electric spindle. Dynamic calibration of the electric pin balance is generally to install the appropriate adjustment bolts in the adjustment hole at the front end of the spindle. Once the vibrator has carried out a dynamic detection of balance on the electric spindle, it will indicate the angle of measurement of the imbalance and the imbalance. in Figure 6.
Figure 6 Detection of the state of mechanical vibration, dynamic balance, the starting and stopping state of the electric spindle
(4) Preventive repair of electric pins for electric pins with relatively simple structures, if there are problems with the bearings and other components of the spit after detection, measurements can be taken to replace the spit bearings and other Components in advance to avoid new degradation of the pin performance. Premature preventive repairs can reduce maintenance costs and extend the lifespan of the electric spindle. As Figures 7 to 9 show, we have carried out preventive and advanced repairs to the electric spit. For repair.
Figure 7 Maintenance of the electric spindle Tramec
Figure 8 Installation of mechanical parts for electric spindle
Figure 9 Replacement of the electric spindle bearing
4. Conclusion
Master The state performance of the electric spindle, monitor the full lifespan of the electric spindle, establish a life story of the electric spindle to predict the lifespan of the electric spindle and make an early warning and prevent the maintenance Electric pin according to the status of the electric spindle, which can extend the lifespan of the electric spindle from 30% to 40%, reaching 5,000 ~ 9,000 hours, reducing maintenance costs and improving the treatment of the parts .
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