What are the common mechanical failures and solutions of duplex spot welder for motor motor rotor?
Motor motor rotor duplex spot welding machine common mechanical failure and solutions:
First, the electrode failure
Failure phenomenon
Electrode wear: The electrode head gradually wears out during the long welding process, resulting in changes in the size and shape of the welded joint and a decline in welding quality. For example, after the electrode is worn, the contact area of the weld joint increases and the current density decreases, which may result in weak welding.
Electrode sticking: The electrode and the motor rotor material may stick under the high temperature of welding, so that the electrode can not be lifted properly, affecting the next welding operation.
Electrode deformation: When the electrode is subjected to large pressure or uneven pressure, deformation may occur, changing the contact state between the electrode and the workpiece, thus affecting the welding quality.
Possible causes
Excessive number of welding operations, excessive welding current or improper selection of electrode material are the main causes of electrode wear. For example, if a lower hardness electrode material is used to weld a high hardness rotor material, the electrode will wear out more quickly.
Improperly set welding parameters, such as too long welding time, too much electrode pressure, or impurities on the surface of the welding material, can easily lead to electrode sticking.
Improper installation of the electrode, such as the electrode is not installed vertically, or the electrode is subjected to lateral force during the welding process, may cause electrode deformation.
Solution
Regularly check the electrode wear, when the electrode is worn to a certain extent, replace the electrode in time. At the same time, according to the welding material and process requirements, select the appropriate hardness and material of the electrode, such as copper alloy electrode.
Optimize the welding parameters, set the welding time and electrode pressure reasonably, avoid too long welding time and too much pressure. Before welding, ensure that the surface of the welding material is clean, and remove impurities such as oil and oxidized layer. If the electrode is sticking, you can use a special electrode cleaning tool to clean the electrode surface, or lightly polish the electrode.
Install the electrode correctly, using a special electrode fixture to ensure that the electrode is installed vertically. During the welding process, check whether the electrode is subjected to lateral force, if so, adjust the position of the welding workpiece or fixture to ensure that the electrode is subjected to uniform force.
WeChat screenshot_20241205091101.png
II. Failure of pressurizing mechanism
Fault phenomenon
Insufficient pressure: The pressure of the electrode on the motor rotor does not reach the set value, resulting in false welding or insufficient welding strength of the welded joint.
Unstable pressure: During the welding process, the electrode pressure is suddenly large and small, resulting in inconsistent quality of welded joints.
The pressurizing mechanism fails to act: the electrode cannot be pressed down normally, resulting in failure to weld.
Possible causes
Insufficient pressure of the pneumatic or hydraulic system (if pneumatic or hydraulic pressurization) may be caused by insufficient pressure of the gas source or hydraulic source, leakage of the gas pipe or oil pipe, or failure of the pressure regulating valve. In the case of mechanical spring pressurization mechanisms, insufficient pressure may be caused by spring fatigue or damage.
The moving parts of the pressurizing mechanism, such as the piston and piston rod of the cylinder or hydraulic cylinder are worn out, or the mechanical transmission parts (such as connecting rod, cam, etc.) are loose or worn out, which can cause unstable pressure.
Failure of the control system of the pressurizing mechanism, such as damage to the solenoid valve (if it is pneumatic or hydraulic), failure of the control circuit, failure of the sensor, etc., may cause the pressurizing mechanism to be unable to operate.
Solution
For pneumatic or hydraulic systems, check the pressure of the air or hydraulic source to make sure it meets the working requirements. Check whether there is any leakage in the air pipe or oil pipe, if there is any leakage, repair or replace it in time. Adjust the pressure regulating valve so that the pressure reaches the set value. For spring pressurization mechanism, replace fatigued or damaged springs.
Check the moving parts of the pressurizing mechanism, and replace the worn piston and piston rod in time. Tighten loose mechanical transmission parts, such as connecting rods, cams, etc., and repair or replace worn parts.
Check the control system of the pressurizing mechanism, such as whether the solenoid valve is working properly, whether the control circuit has broken or short-circuit phenomenon, and whether the sensor accurately detects the pressure signal. For damaged solenoid valves or sensors, replace them in time and repair the control circuit failure.
Third, the fixture failure
Failure phenomenon
Loose fixture: In the welding process, the motor rotor fixture is loose, resulting in rotor position offset, affecting the welding accuracy.
Damage to the fixture: the fixture's collet, locating pin and other components are damaged, unable to accurately fix the motor rotor, so that the welding position is not accurate.
Flexible opening and closing of the fixture: the fixture cannot clamp and loosen the motor rotor quickly and accurately, which reduces the welding efficiency.
Possible reasons
The fastening screws are loosened after the fixture has been used for a long time, or the positioning surface of the fixture is worn out, resulting in the loosening of the fixture.
Differences in the size and shape of the motor rotor, or the fixture is subjected to excessive external impact, which may damage the collets, positioning pins and other parts of the fixture.
Worn or jammed parts of the fixture's mechanical transmission parts, such as connecting rods, slides, etc., or malfunctioning of the fixture's pneumatic or hydraulic devices (if any), can cause the fixture to open and close inflexibly.
Solution
Regularly check the fastening screws of the fixture and tighten the loose screws in time. For worn out positioning surfaces, either grind and repair them or replace the fixture parts that are badly worn out.
According to the size and shape of the motor rotor, select and adjust the fixture reasonably. Avoid the fixture to be impacted by excessive external force, and hold it lightly during operation. When the fixture's collet, locating pin and other parts are damaged, replace the parts with the same specification in time.
Check the mechanical transmission part of the fixture, clean up the foreign matter on the worn or jammed parts, add lubricant to make it restore the flexible movement. For pneumatic or hydraulic device failure, check the gas or hydraulic source, gas or oil pipe, solenoid valve and other parts, repair or replace the damaged parts.
Fourth, the body and table failure
Fault phenomenon
Body vibration: abnormal vibration of the body during the welding process, affecting the welding accuracy and equipment stability.
Deformation of the worktable: the surface of the worktable is not flat, resulting in unstable placement of the motor rotor, affecting the welding quality.
Loose connection between the machine body and the working table: the connection between the machine body and the working table is loose, which makes the overall structure of the equipment unstable.
Possible causes
The vibration of the machine body may be caused by the imbalance of the motor and other moving parts, poor installation of the base or excessive impact force generated during welding.
Long-term exposure of the worktable to heavy loads, high temperature or external impact may cause deformation.
Loose connection screws of the fuselage and table, worn connection pins or aging of vibration damping pads may cause loose connection.
Solution
Check the balance of the motor and other moving parts, and adjust or replace the unbalanced parts. Check whether the base is firmly mounted, if it is loose, re-tighten the base. During the welding process, the welding impact can be reduced by adjusting the welding parameters.
For the deformed worktable, you can use the level meter and other tools to detect and repair according to the degree of deformation. Slight deformation can be dealt with by grinding and leveling, while serious deformation may require replacement of the worktable.
Regularly check the connecting parts between the body and the table, tighten the loose screws, replace the worn connecting pins, and replace the aging shock absorbing pads to ensure that the body and the table are firmly connected.
※ If you still can't solve the problem by the above ways and means, please contact the technical specialists of Xinhui Mechanical & Electrical Equipment Co.
