JB/T 11991-2014AC Servo Motors for Numerical Control System of Industrial Machine (English PDF)

3.1 Duty zone

The area where the motor can operate continuously under the condition that the KTb - Torque ripple coefficient, %; Tmax - Maximum instantaneous torque, in Newton-meters (N·m); Tmin - Minimum instantaneous torque, in Newton-meters (N·m).

3.15 Cogging torque (static friction torque)

The maximum torque value that can be applied to the motor shaft without causing rotation when the motor is not energized.

4.1 Basic requirements

4.1.1 Classification

Motors are basically classified into sine wave driven AC permanent magnet synchronous servo motors and square wave driven AC permanent magnet synchronous servo motors, according to their driving method.

4.1.2 Model

Motor models are named according to GB/T 10405-2009 and relevant requirements, generally consisting of the frame number, product name code, etc. The motor model name is specified by the specific product technical standard.

4.1.3 Basic external structure

The basic mounting type of the motor is an end face spigot with a flange.

The basic shaft extension type of the motor is a cylindrical shaft extension with a keyway. The shaft extension diameter and keyway shall comply with the relevant provisions of GB/T 756-2010.

4.1.4 Cooling method

The motor cooling method shall be enclosed self-cooling or enclosed forced-cooling.

4.1.5 Duty cycle

The motor's duty cycle shall generally comply with the provisions of GB 755-2008. For motors with non-continuous operation, the manufacturer shall clearly specify and label this.

4.1.6 Nameplate and markings

A durable and clearly legible nameplate shall be affixed to a conspicuous part of the motor. The nameplate content includes (but is not limited to). manufacturer's name and registered trademark, product model and name, product serial number, manufacturing date, rated voltage, rated speed, rated torque (rated power), insulation class, IP protection rating, mass (that is, weight), etc.

In addition, each motor product shall have anti-electric shock, anti-high temperature, and necessary safety warning signs.

The lettering on the motor nameplate and markings shall be clear, durable, accurate, in the correct color. The installation (or attachment) of the motor nameplate and markings shall be firm and durable, and not crooked (see Figure 2).

4.2 Inspection of basic requirements

The motor model, external structure, DC bus voltage, cooling method, duty cycle, motor nameplate markings shall be visually inspected or tested, which shall comply with the provisions of 4.1.2 ~ 4.1.6.

For non-adhesive motor nameplates and markings, a test shall be conducted by wiping the nameplate and markings with a damp cotton cloth soaked in water for 15 seconds; then wiping with a cotton cloth soaked in gasoline for 15 seconds, wiping one round trip per second. After the test, the nameplate and markings shall comply with the provisions of 4.1.6.

5.1 Appearance

5.1.1 Requirements

5.8.1 Requirements

The length of each motor lead wire is determined by the design. Each lead wire shall be able to withstand a tensile force of >= 9 N. After the test, the lead wire shall not break; the insulation layer and core wire shall not be damaged.

5.8.2 Inspection (test) method

With the motor lead wires pointing downwards, a force of 9 N is applied vertically downwards to the outer end of each lead wire. The force shall be applied evenly to the conductor core and insulation layer.

For motors with end-mounted wiring, the test shall be conducted at room temperature.

First, the shaft extension is positioned vertically upwards, then the motor is rotated 90° so that the shaft is horizontal and then the motor casing is rotated 360° clockwise and counterclockwise around the shaft axis. The test shall meet the requirements of 5.8.1.

For motors with radial wiring, the test shall be conducted at room temperature. First, the motor is placed horizontally with the leads pointing downwards, then the motor is rotated 90° so that the shaft extension is vertically upwards, then the motor casing is rotated 360° clockwise and counterclockwise around the axis of the wiring hole. The test shall meet the requirements of 5.8.1.

6.1 Insulation resistance

6.1.1 Requirements

The motor shall have sufficient insulation resistance values after normal testing, high-temperature testing, extreme low-temperature testing, alternating damp heat testing. The insulation resistance values shall comply with the following requirements.

a) Under normal test conditions and extreme low-temperature test conditions, the insulation resistance value between each winding and the motor casing, and between each winding, shall not be less than 50 Mohm;

b) Under the corresponding high-temperature conditions, the insulation resistance value shall not be less than 10 Mohm;

c) After the alternating damp heat test (after being left for 2 hours after the end of the test), the insulation resistance value shall not be less than 1 Mohm;

d) The voltage requirements for the testing instrument used for insulation resistance testing are shown in Table 7.

When repeating the withstand voltage test, the test voltage shall be 80% of the specified value.

The test can also be performed with a test time of 1 second; the test voltage shall be 120% of the value specified in Table 8.

6.2.2 Inspection (test) method

The high-voltage power supply used for the test shall have a frequency of 50 Hz; the power supply waveform shall be approximately sinusoidal. The power supply's power and output impedance shall ensure that there is no significant waveform distortion or significant voltage change under various loads. The test equipment shall be able to distinguish between winding leakage current and surge current.

The motor is subjected to the test voltage according to the provisions of 6.2.1. The voltage value shall start from no more than half of the full test voltage value; then be increased uniformly or in steps of no more than 5% of the full voltage value, until the full value is reached. The time from half value to full value shall not be less than 10 seconds; the voltage shall be maintained at the full value for 1 minute. Throughout the entire test process, the voltage peak shall not exceed 1.5 times the specified effective value. Monitor the fault indicator, to determine whether there is breakdown discharge in the motor; monitor the leakage current value (record the leakage current value if necessary).

At the end of the test, the test voltage shall be gradually reduced to zero to avoid surges.

After the test, measure the insulation resistance according to 6.1.2; its value shall meet the requirements of 6.1.1.

6.3 Protective connection (Protective grounding)

6.3.1 Requirements

According to the provisions of GB 5226.1-2008, Article 8.2, the motor casing and all conductive parts shall have a firm, reliable, good electrical connection with the protective connection device; the following requirements shall be met.

a) The metal casing of the plug shall be connected to the protective connection device;

b) The protective connection circuit shall only be disconnected after all energized conductors are disconnected;

c) The re-establishment of the continuity of the protective connection circuit shall be before all energized conductors are reconnected;

d) The cross-sectional area of the protective connection wire S protection shall be at least the same as the cross-sectional area of the phase wire of the same type of motor S phase (i.e., S protection = S phase);

The motor shall operate at rated speed under no-load conditions; the noise shall be measured according to the methods specified in Chapter 5 and relevant provisions of GB/T 10069.1-2006, meanwhile shall meet the requirements of 6.5.1.

6.6 Rotation direction

6.6.1 Requirements

The motor's rotation direction shall be bi-directional reversible. According to the wiring markings specified in the design. U phase (blue), V phase (red), W phase (yellow) wiring, viewed from the end face of the motor drive shaft at the mounting interface, the counterclockwise rotation direction of the motor drive shaft is defined as the positive direction of motor rotation.

6.6.2 Inspection (test) method

Connect the wiring and power on according to the requirements of 6.6.1. When the servo drive unit is given a positive command, viewed from the end face of the motor drive shaft at the mounting interface, the rotation direction of the motor shall conform to the provisions of 6.6.1, i.e., counterclockwise rotation.

6.7 No-load current

6.7.1 Requirements

When the motor is operating at rated speed under no-load conditions, its no-load current shall comply with the provisions of the special technical standard (or design).

6.7.2 Inspection (test) method

When the motor is operating at rated speed under no-load conditions, measure the no-load current on the motor stator winding. The maximum value shall comply with the provisions of 6.7.1.

6.8 Temperature rise

6.8.1 Requirements

Motor temperature rise is generally measured by the change in winding resistance.

For motors with Class F insulation structure windings, the temperature rise of the motor stator winding shall not exceed 105 K when operating continuously in the continuous duty zone. For Class B insulation structure windings, the temperature rise shall not exceed 80 K.

6.8.2 Inspection (test) method

The motor temperature rise test uses the resistance method. […]