Common faults and solutions for CNC machine tool spindles IV

Problem five:The spindle stops immediately after starts.

The cause of the failure and the solution:

1. System output pulse time is not enough: adjust the system's M code output time.

2. The inverter is in jog state: Refer to the instruction manual of the inverter and set the parameters.

3. The control components of the spindle line are damaged: check whether the contacts on the circuit are in good contact, check whether the DC relay is damaged which caused the contact can not self-lock. 

4. The spindle motor is short-circuited, causing thermal relay protection: find the cause of the short circuit and reset the thermal relay.

5. The spindle control loop does not have self-locking circuit, and the parameter is set to pulse signal output, so that the spindle can not operate normally: change the start and stop parameters of the system control spindle to the level control mode.

Problem six: the spindle rotation can not stop

The cause of the failure and the solution:

1. AC contactor or DC relay is damaged and uncontrollable: replace AC contactor or DC relay.

Common faults and solutions for CNC machine tool spindles III

Problem three: the rotating speed of the spindle without frequency conversion (shift spindle) is not controlled

The cause of the failure and the solution:

1. System has no S01-S04 control signal output: Check whether the system has shift control signal output. If no, it is system failure, replace the IC or send the factory for repair.

2. Connection line failure: If the system hasshift control signal output, check whether there is any open circuit or poor contact on each connection line, and check whether the DC relay or AC contactor is damaged.

3. The spindle motor is damaged or open circut : Check the spindle motor.

4. Machine is not linked: hang up the gear.

Problem four: the spindle has no brake

The cause of the failure and the solution:

1. Abnormal brake circuit or strong electrical components damage: Check whethr bridge stack, fuse or AC contactor is damaged; check if the high-voltage circuit is open.

2. Braking time is not long enough: adjust the braking time parameter of the system or inverter.

3. System has no brake signal output: replace internal components or send to the factory for repair.

4. The inverter control parameters are not adjusted: Check the inverter manual and set the inverter parameters correctly.

Common faults and solutions for CNC machine tool spindles II

Problem two: the spindle with the inverter does not turn​

The cause of the failure and the solution:

1. Mechanical transmission failure: Check whether the driving belt is broken or whether the machine tool is in neutral.

2. Three-phase power supply to the spindle is missing: Check the power supply and exchange any two power lines.

3. The inverter control parameters of the CNC system are not open: see the system manual to understand the inverter parameters and change them.

4. Line connection error between the system and the inverter: Check the connection manual of the system and the inverter to ensure the connection is correct.

5. The analog voltage output is not normal: Check whether the analog voltage output by the system is normal with a multimeter; check whether the analog voltage signal line connection is correct or the contact is good, and the analog voltage received by the inverter matches.

6. High-voltage control part is disconnected or component is damaged: Check whether the connection of each contact of the spindle power supply is reliable and whether the DC relay is damaged or the fuse is burnt out.

7. Inverter parameters are not adjusted: The inverter contains control mode selection, which is divided into inverter panel control spindle mode, NC system control spindle mode, etc. If NC system control mode is not selected, we can not control spindle with system; check if the relevant parameter settings are reasonable or change them if necessary. 

Common faults and solutions for CNC machine tool spindles I

Problem one: the spindle without frequency conversion does not turn

The cause of the failure and the solution:

1 Mechanical transmission failure: Check whether the driving belt is broken or whether the machine tool is in neutral.

2 Three-phase power supply to the spindle is missing or inverting: Check the power supply and exchange any two power lines.

3 Wrong circuit connection: Carefully refer to the circuit connection manual to ensure that the connection is correct.

4 The system has no corresponding spindle control signal output: use the multimeter to measure the system signal output terminal. If there is no spindle control signal output, you need to replace the relevant IC components or send it to the factory for maintenance.

5 The system has the corresponding spindle control signal output, but there is an open circuit or component damage in the power supply line and the control signal output line: use the multimeter to check the power supply circuit between the system and the spindle motor, and whether there is an open circuit in the signal control circuit; whether contact between the wires is not good; whether AC contactor or DC relay is damaged; check if the thermal relay is overcurrent; check if the fuse is burnt.

Method of Judging Grease Metamorphism

In order to provide better performance, the bearings are lubricated by lubricating grease, which can reduce the friction and temperature of the bearings, if the grease is bad. Not only does not play a related role, but is more adverse to the use of bearings, so we must learn how to buy grease to tell whether the grease has deteriorated.

  

Method of judging grease metamorphism

1. Oil flow observation method

    Take two measuring cups , one of the lubricating oil to be inspected , the other empty on the desktop , lift the measuring cup full of lubricating oil away from the table top 30 - 40 cm and tilt , let the lubricating oil slowly flow into the empty cup , observe the flowing condition , the quality good lubricating oil oil flow should be slender , uniform and continuous , if the oil flow is lost or slow , and there is large flow of oil , the lubricating oil has deteriorated .

2. Hand twisting

    Twisting lubricating oil between thumb and index finger repeatedly grinding, a better lubricating oil hand feel lubricity, less debris, no friction, if feel the sand between fingers such as a greater sense of friction, it shows that there are many impurities in the lubricating oil. New lubricating oil should be replaced if it cannot be used again.

3.Illumination method

     On sunny days, use a screwdriver to lift the lubricating oil at an angle of 45 degrees to the horizontal level. Compare the sunlight and observe the oil droplets. Under light, you can clearly see that the lubricating oil is good without debris and can continue to function. If there is too much debris, replace the lubricating oil.

4. Oil drop trace method

    Take a clean white filter paper, drop a few drops on the filter paper, after oil leakage, if the surface of black powder, with the hand touch has a sense of resistance, then the lubricating oil has a lot of impurities. Good lubricating oil without powder, touch dry and smooth with hands, and yellow marks.

General information of ZYS needle bearing

The needle bearing is roller bearing with a cylindrical roller, which is both thin and long with respect to its diameter. In spite of the smaller cross-section, the bearing still has a high load bearing capacity. The needle bearing is equipped with thin and long rollers (roller diameter D ≤ 5mm, L/D ≥ 2.5, L means the length of the roller), therefore its radial structure is compact. When the inner diameter size and load capacity are the same as those of other types, the outer diameter is the smallest, which is particularly suitable for a support structure in which the radial installation size is limited.

Structure type
This type of bearing has a radial needle and thrust full of ball, or with a thrust ball, or with a thrust cylindrical roller, or with the angular contact ball into one, can withstand unidirectional or two-way axial load. Can also be designed according to the user's specific structural requirements.
Materials
Needle roller material for the GCr15 bearing steel, hardened HRC60-65.
Inside and outside the ring material for the GCr15 bearing steel, hardened HRC61-65.
The cage material is made of high quality mild steel or reinforced nylon.
Application
It is widely used in machine tools, metallurgical machinery, textile machinery and printing machinery and other machinery and equipment, and mechanical design can be more compact and smart.

http://www.zys-bearings.com/bearing/the-needle-bearing.html

High temperature adaptability of bearings

The high temperature adaptability of the bearing and the heat treatment process of the bearing within an outer diameter of  240 mm ensure that it is dimensionally stable below 150 degrees. Special heat treatments are required if the operating temperature is above 150 degrees. These bearings are marked with the suffixes S1 to S4 (DIN 623).

S1: Maximum operating temperature 200 degrees

S2: Maximum operating temperature 250 degrees

S3: Maximum working temperature 300 degrees

S4: Maximum operating temperature 350 degrees

Bearings with an outer diameter＞240 mm are generally stable at temperatures below 200 degrees. The bearings use the cages made of glass fiber reinforced nylon 66 and can be stably operated at working temperatures below 120 degrees. When this kind of bearing is lubricated with oil, if the oil contains additives, the life of the cage may be shortened. When the temperature exceeds 120 degrees, the aged lubricant will also shorten the life of the cage. Therefore, you should pay attention to observe and replace the lubricant as scheduled.

The allowable temperature of sealed bearing also depends on the filled grease and the requirements of the contact seal. Sealed bearings are lubricated with specially tested high quality lithium grease. This grease can withstand high temperatures of 120 degrees in a short time. If the stable operating temperature reaches 70 degrees or higher, the life of standard lithium grease will be shortened.

ZYS has special technical team to develop the lubricant to meet the different kinds of bearing. If you want to know more, please check http://www.zys-bearings.com/bearing-materials/lubricant/antirust-oil-for-bearing.html.