Thermal shrinkable materials are divided into heat shrinkable tubes and heat shrinkable tapes according to the shape of the supply. According to different uses and applications in different parts of the motor, the application of thermal shrinkable materials in the motor is explained.
Application of a heat shrinkable tube on motor
L, lead wiring identification system
Because of its good electrical performance, copper stability, solvent resistance and corrosion resistance of impregnating paint, the heat shrinkable sleeve can also be marked with marking letters according to the requirements of motor design, so the heat shrinkable marking tube can be used to replace the traditional metal aluminium sheet which is easy to fall off and break when designing the lead wire of motor stator and its winding accessories. Wiring identification system.
The shrinkage rate of heat shrinkable pipes, the uniform identification of all series of motors, and the striking and beautiful identification should be taken into account when using heat shrinkable pipes as lead marks in the design of lead wires. The radial dimensions of heat shrinkable pipes, the printed letters and their colours, and the colours of heat shrinkable pipes should be specified in detail.
2. Special motors are insulated and sealed.
The temperature rise of H-class motor cable is high, and the quality of silicone rubber cable is unstable sometimes. The insulation of H-class motor stator cable is protected by heat shrinkable tube, which can improve the reliability of the motor.
Thermal shrinkage pipe has corrosion resistance (158 C, 7 days), and the three-proof coating on the end of coil can not be applied on the lead-out wire, so when TH treatment motor stator lead-out wire is designed, the insulating part of TH treatment motor stator lead-out wire is covered with thermal shrinkage pipe insulation protection, which can play the role of sealing, moisture-proof, salt fog-proof and mildew-proof. .
3. Heat shrinkable tube heat shrinkable process
Regardless of whether the heat shrinkable pipe is used as the lead sign or the special motor lead wire as the insulation and sealing protection material, only the heat shrinkable process is scientific and reasonable, which can ensure the heat shrinkable pipe reliable, practical and stable. The following is the heat shrinkable process and points for attention.
1) Radial dimension design and thermal shrinkage bursting: the shrinkage of the heat shrinkable tube is more than 50% along the radial direction after heating. In order to ensure that the heat shrinkable tube is firmly fixed on the carrier, its radial dimension must be selected appropriately. The radial dimension is too large to be fixed firmly after heat shrinkage, and the radial dimension is too small to cause explosion when heat shrinkage and motor baking.
2) bake tools and baking efficiency: heat shrinkable tubes can be heated by electric hair dryer, heating trough, oven and other tools. In practical operation, the blast electric heating gun with mobile power supply is the most efficient and convenient to bake the shrinkage tube.
3) The shrinkage position and virtual shrinkage are insufficient. There are two requirements for the heat shrinkage position of the heat shrinkage pipe used as the lead sign: one is to be close to the cold-pressed terminal, and the other is that the shrinkage position of the three (or six or nine) leads should be basically even. If shrinkage causes virtual shrinkage (bottom below), after handling, dipping and curing, the shrinkage position of Suzhou shrinkage pipe may be uneven, slightly affecting the visual effect, seriously affecting the role of thermal shrinkage marking, or even falling off. The shrinkage of heat-shrinkable pipes made of insulating and sealing protective materials for special motors may cause the shrinkage position to move and affect the protection of the connecting end or cold-pressed end of lead wires and cables. In addition, it is better to inspect the shrinkage pipe when the material enters the factory, so as to avoid the phenomenon of insufficient shrinkage of the heat shrinkage pipe (it will not shrink when it reaches a certain temperature or rises again).
4) Adhesion and protection of impregnating paint: Because many motor manufacturers use epoxy impregnating paint to impregnate baking motor, in order to prevent the heat shrinkable tubes from adhering to each other during baking, the heat shrinkable tube cable must be fixed by appropriate methods before impregnating paint. The internal pressure mounting motor can use upper concave baffle to prevent adhesion.
5) Dirt and protection: The process of dipping paint, wiring of junction box and so on may dirty the label of heat shrinkable pipe. Therefore, the corresponding protection measures should be given and the inspection should be strengthened in the heat shrinkable process.
6) Heat-shrinkable pipe identification test: the identification letter test refers to JB62l3.1-92, > General Provisions for the First Part of Electric Winding Leading Soft Cable and Soft Wire > 8.1.2, > the shrinkage test refers to supplier enterprise standards, and the radial dimension test refers to ASTM designation: D876-80. Section 7 (Conical Thermal Steel Meter) measuring equipment.
Application of two heat shrinkable belt on motor
Insulation repair of L and lead cable
1) Repair of lead cracking and a little carbonization during welding: Due to factors such as lead material, manufacturing technology and improper operation during welding, partial cracking and a little carbonization will occasionally occur at one end of lead winding during gas welding between coil winding and lead cable, and heat shrinkage bandage is used to wrap up the lead winding. The heat shrinkable part can be used to enhance mechanical strength and insulation.
2) Restoration of bonding and tearing of lead wire during soaking and drying: Although the process requires that the shell of lead wire and outlet hole should avoid contact, and the contact between lead wire and rotating shaft should be avoided, it is difficult to guarantee in actual production. Once the motor stator and rotor are soaked and dried, the lead wire will be torn due to adhesion. At the same time, the "injured" part can be wrapped with thermal shrinkage belt, and then fixed by thermal shrinkage.
3) Repair of lead wire and cable during motor repairing and repairing: motor repaired before leaving factory, motor repaired during three-package period, etc. Any similar problems such as lead wire damage and cracking can be solved by thermal shrinkage.
2. TH handles rotor winding of motor rotor.
After connecting the copper flat lead wire of the insertion winding of the rotor with the collector ring and its insulation treatment, the group lead wire is wrapped with heat shrinkable tape, which plays the role of insulation protection, moisture proof and so on. It can improve the reliability and service life of the motor.
3) 热缩位置与虚缩、缩量不足：用作引接线标识的热缩管，热缩位置有两个要求：一是要靠近冷压端子处，二是缩固在三根(或六、九根) 引接线上的位置应基本平齐。如热缩时导致虚缩(如下底部)，在搬运、浸漆、热固化工序后，苏州热缩管的缩固位置可能参差不齐，轻微时影响视觉效果，严重时影响热缩标识作用，甚至可能脱落。特殊电动机用绝缘、密封保护材料的热缩管，虚缩可能导致缩固位置移动，影响引接线电缆连结端或冷压端的保护作用。另外在材料进厂时最好检验热缩管，避免出现热缩管缩量不足的现象(达到一定温度或再升温也不缩)。
6)热缩管标识检测：标识字母的检测参照JB62l3．1-92<<电机绕组引接软电缆和软线第一部分一般规定>>8．1．2款；缩量检验参照供应商企业标准；径向尺寸检验参照ASTM designation：D876—80．第7款(锥热 形钢计量计)测量设备。