Rotor Testing Machine For Broken Bar / Squirrel-Cage Rotor Testing

1. Importance of testing rotor

• The low efficiency, high temperature rise and high slip ratio will be caused by the increasing of rotor resistance and consumption.
• The broken bar will increase the resistance and lower the start torque.

2. Technical specification

3. Test process

3.1 Set test items and parameter range for different rotor models, and select the corresponding model before test.

3.2 Put the tested rotor on the test bench and fix it.

3.3 Press two start buttons to test, the indicating light displays “in test’

3.4 All test items are performed automatically, and the operator is not allowed to touch the rotor during the test.

3.5 Pass or fail signal will be triggered after completing the test.

4. The reason of broken bar

4.1 Broken bar is caused by tension fracture. When the rotor iron cores are over pressed and the false shaft exits, the iron core may break when it expands outward, if the aluminum solid is not fully solidified during the demolding process, the cage bar will break because of premature tapping of the die. if vibration time is too long, the broken bar also appears.

4.2 The iron core slot is in wrong position or blocked, which reduce the slot section area and cause blockage in the process of pouring liquid.

4.3 Forgotten punched slot or mixed foreign substance will block the slot and separate the aluminum liquid when pouring the aluminum liquid.

4.4 Broken bar caused by slot porosity.

4.5 The low temperature of iron core affects the aluminum liquid fluidity, which is important to gravity casting aluminum.

4.6 Broken bar is caused by the way when there was time gap when pouring the aluminum. The poured aluminum water cannot be combined since the aluminum water is easy to be oxidized, and "cold partition" appears.

5. Rotor testing machine picture