1. The temperature of the motor is too high or the motor is faulty with smoke

the reason:

1). Excessive load

2). Two-phase operation

3). Air duct blocked

4). Increased ambient temperature

5). Short circuit between phases or turns of stator windings

6). The stator winding is grounded

7). The power supply voltage is too high or too low

Repair method:

1). Reduce the load or choose a large-capacity motor

2). Clear the air duct

3). Take cooling measures

4). Check the power supply voltage at the input end with a multimeter and voltmeter

  1. Motor failurefor electricity phenomenon of motor shell.

the reason:

The winding is damp, the insulation is aging, or the lead wire collides with the junction box shell;

Repair method:

Corresponding motor repair method: dry the motor shell, replace the winding;

  1. Motor failurefor motor vibration

the reason:

1). Rotor imbalance

2). Shaft bending

3). Unbalanced belt pulley

4). Uneven air gap produces unilateral magnetic pull

Repair method:

1). Correct dynamic and static balance

2). Straighten the shaft or replace it ,when shaft is not severely bent, it can be turned to 1-2mm and then fitted with a sleeve

3). Correction balance

4). Re-adjust

4.Motor failure for current three-phase unbalanced

the reason:

1). The power supply voltage is seriously insufficient

2). Three-phase turns are not equal

3). Internal wiring error

Repair method:

1). Check the power supply voltage

2). Replace or handle the motor

3). Correct the wiring

  1. Motor failurefortoo large no-load current

the reason:

1). Large air gap between stator and rotor

2). Too few turns of stator winding

3). Improper assembly

Repair method:

1). Adjust and reduce the air gap

2). Re-verify and bypass

3). Reassembly

  1. Motor failurefor reduce ofInsulation resistance

the reason:

1). The stator gets wet;

2). Excessive dust;

3). Insulation damage;

4). Insulation aging;

Repair method:

1). Drain and remove moisture;

2). Clean up dust ;

3). Repair;

4). Replace;

  1. When the winding fails, a part of the servo motor will be short-circuited, causing the motor to burn. The possible reasons are:

1). Overload

2). Overpressure

3). Lack of phase

4). Wrong wiring

5). Improper drive parameter settings

6). The ambient temperature is too high

7). The cooling device fails

8). Physical damage

When the winding fails, a part of the servo motor will be short-circuited, and the countermeasures to internal burning of the motor are:

1). Do not exceed the rated load for a long time when using the servo motor

2). Monitor current and current accumulation over time

3). Monitor the winding temperature

4). The rotor and shaft are different from asynchronous motors. The rotor of a servo motor is usually composed of permanent magnets. The permanent magnet pieces are fixed on the shaft of the motor by means of facing or embedding.

  1. Noise

1). Increase the mechanical rigidity and reduce the inertia of the system, and reduce the response time of the mechanical transmission parts, such as replacing the V-belt with a direct screw drive or using a gear box instead of the V-belt;

2). Reduce the response speed of the servo system and reduce the control bandwidth of the servo system, such as reducing the gain parameter value of the servo system.

the above is only one of the causes of noise and instability. For different reasons, there will be different solutions, such as noise caused by mechanical resonance. In the servo, methods such as resonance suppression and low-pass filtering can be adopted. In short, noise and the instability are basically not caused by the servo motor itself.

Other problem solving skills of servo motor

  1. Motor movement: movement occurs during feeding, and the speed measurement signal is unstable, such as a crack in the encoder; poor contact of the terminal, such as loose screws, etc.; when the movement occurs in the movement from the forward direction and the reverse direction At the moment of commutation, it is generally due tothe backlash of the feed drive chain or the big servo drive gain
  2. Motor crawling: Most of it occurs in the start acceleration section or low-speed feed, usually due to the poor lubrication state of the feed transmission chain, low servo system gain and excessive external load. Especially note that the servo motor and balland the coupling used for screw connection, due to the loose connection or the defects of the coupling itself, such as cracks, the rotation of the ball screw and the servo motor are not synchronized, so that the feed movement is fast and slow;
  3. Motor vibration: When the machine tool runs at high speed, vibration may occur, and an over-current alarm will be generated at this time. Machine vibration problems are generally speed problems, so you should checkspeed loop problems;
  4. Motor torque reduction: When the servo motor is running from the rated locked-rotor torque to high-speed operation, it is found that the torque will suddenly decrease, which is caused by the heat dissipation of the motor winding and the heat of the mechanical part. At high speed, the temperature rise of the motor becomes larger, therefore,the load of the motor must be checked before using the servo motor correctly;
  5. Motor position error: When the servo axis movement exceeds the position tolerance range (KNDSD100 factory standard setting PA17: 400, position out of tolerance detection range), the servo drive will appear "4" position out of tolerance alarm. The main reasons are:

The tolerance range set by the system is small; the servo system gain is set improperly; the position detection device is polluted; the cumulative error of the feed transmission chain is too large;

  1. The motor does not turn: In addition to connecting the pulse + direction signal from the CNC system to the servo drive, there is also an enable control signal, which is generally DC +24 V relay coil voltage. Servo motor does not rotate, common diagnostic methods are: check whether there is a pulse signal outputin the CNC system; check whether the enable signal is turned on; observe whether the input/output status of the system meets the starting conditions of the feed axis through the LCD screen; confirm that the brake has been opened for the servo motor with electromagnetic brake; the drive is faulty: servo motor malfunction;servo motor and ball screw connection coupling failure or key disconnection, etc.