In the actual production of machinery manufacturing enterprises, it is often found that some geared motors have not been used for a period of time. When they are used again, the insulation resistance of the geared motor windings is found to be reduced. Especially in the rainy season, the air humidity is high, and the insulation value may even change. If it is reduced to zero, it should be dried at this time to make the insulation resistance and absorption ratio reach the specified value. If it is put into operation hastily, it may cause the insulation breakdown of the geared motor coil and cause an accident.

Like many mobile phones accidentally dropped into the water, the easy way to solve its dampness and water ingress is to dry it. Although drying is simple on the surface, it also requires a certain method for precision products such as geared motors. For the drying method, the first thing we think of is the heating treatment or the so-called grilling. Here we can summarize it as the external heat source heating method, but there are some other more complicated methods. The geared motor will decelerate from the gear below. The motor drying method is complicated.

1. Drying method of DC welding machine
The operation wiring of the drying method of the direct current welding machine is similar to that of the alternating current, and the string ammeter should be a direct current meter. It is convenient to use a DC welding machine to dry the damp gear reduction motor, and it can dry large and medium-sized gear reduction motors and high-voltage gear reduction motors for a long time. In this way, when the electric welding machine works for a long time or high current, its internal components will not be damaged due to long time high current work, so it can be used for a long time for large and medium geared motors. It is worth noting that: when using this electric welding machine to dry, all contacts must be in good contact and fastened. The welding machine's lead wire must use a special wire, and the cross-section size should meet the current carrying capacity of the electric welding machine. Pay attention to the cooling of the transformer of the electric welding machine, and ensure that the insulation resistance of the geared motor cannot be lower than 0.1MQ. Also pay close attention to the winding temperature of the gear reducer motor, and adjust the voltage and current in time.

2. Drying method of AC welding machine
Before the operation of the AC welding machine drying method, connect the 6 terminals of the damp gear reducer motor windings in series, and the casing is grounded, so that the three sets of windings can be heated and dried. In order to monitor the current changes during the drying process, one can be connected in series. With only an ammeter, observe whether its current reaches 60% to 70% of the rated current of the gear reducer motor. Drying the gear reduction motor with an China Motor Drivers Manufacturers does not require disassembly and inspection of the gear reduction motor, which reduces the workload. At the same time, the gear reduction motor uses its own resistance to generate heat when it is energized, so that the coil is evenly heated, and the drying effect is better. This method is only suitable for geared motors below 100KW, and cannot be used for a long time, because the current applied to the welding machine transformer is relatively large when the AC welding machine is working, and it cannot be used for a long time, otherwise the welding machine may be burned out.

3. Excitation coil drying method
The excitation coil drying method is to wind the excitation coil on the stator coil iron core of the gear reduction motor, and apply alternating current to make the stator generate magnetic flux, and rely on its iron loss to dry the gear reduction motor stator. When using this method, it should be noted that the current in the excitation coil cannot exceed the current carrying capacity of the wire. At the same time, the temperature rise of the stator coil should be monitored so that it does not exceed the maximum value allowed by the manufacturer. If you want to increase the drying speed, you can appropriately increase the input voltage of the excitation coil (the number of turns of the excitation coil should be increased by the same time). It is worth noting that this method is suitable for large-scale geared motors with high power and not easy to move on site, but a leakage protector should be used when the excitation coil is energized, and the selected excitation coil requires that the temperature of the geared motor stator rises. It can meet its good insulation performance when it is high.

4. External heat source heating method
For the damp gear reducer motor, first disassemble it and inspect it, then put a high-power incandescent bulb into the gear reducer motor to bake it, or put the gear reducer motor in a drying room for drying. This method is easy to operate, safe and reliable, but it is only suitable for small geared motors that are easy to disassemble and inspect. For large and medium-sized or geared motors that are not easy to disassemble and inspect, the workload is relatively large, and the feasibility is also reduced. It should be noted that the light bulb or heat source should not be too close to the coil during operation of this method to prevent the coil from being burnt out, and items such as canvas can be added to the gear reducer motor housing for heat preservation.

(1) Selection of gear parameters
1. Under the premise of satisfying the bending fatigue strength, when the center distance is constant, more teeth should be selected, which can increase the coincidence degree, make the transmission stable, and reduce the noise. On the premise of meeting the transmission requirements, the number of teeth of the large and small gears should be mutually primed to disperse and eliminate the influence of gear manufacturing errors on the transmission. It can also prevent a certain tooth on the large and small gears from meshing with each other periodically to make the transmission smooth Reduce noise.
2. Using a smaller pressure angle can reduce the running noise. Considering the influence of intensity comprehensively, the standard value of 20 is usually taken. When the structure permits, helical gears should be given priority, and its vibration and noise are greatly reduced compared with spur gears. Generally, the helix angle is required to be selected between 8-20.
3. Under the economic capacity that the user can bear, the precision level of the gear should be improved as much as possible when designing. High-precision gears produce much less noise than low-precision gears. In order to reduce the noise of the gear reducer, when the gear backlash is selected, if the transmission is pulsating rotation, a smaller backlash should be selected. If it is a more even and balanced load, a slightly larger tooth backlash should be selected.

(2) Selection of gear structure
1. Under the conditions permitted by the overall structure and design specifications, appropriately increase the tooth width. In this way, the unit load of the gear can be reduced, the deformation of the gear can be reduced, and the transmission noise can be reduced.
2. When designing gears, solid structures should be avoided as much as possible, and web structures should be designed. In the case of meeting the strength, the weight of the gear should be reduced as much as possible. In this way, the natural frequency of the gear can be reduced, thereby reducing the noise of meshing.
3. The optimized design of the cabinet can reduce noise and vibration. Specific noise reduction methods include: using acoustic sound-absorbing materials, using a combined isolation frame, and increasing the rigidity of the box. The main design principle is to ensure that the resonance of the gear reducer box and other supporting parts differs by at least 20% from the rotation speed, the multiple of the rotation speed, and the meshing frequency of the gear teeth.
4. Bearing selection "In order to reduce the noise of the gear reducer, in general design, the type, fit and clearance of rolling bearings should be reasonably selected according to the requirements of use. In high-speed transmission, fluids that run more smoothly than rolling bearings should be used Lubricate the bearings.
 
(2), manufacturing and process
1. Gear modification adopting gear trimming can effectively reduce the impact in gear transmission. Gear trimming includes tooth tip trimming and tooth root digging as well as tooth direction and tooth profile trimming. They can make the convex tooth surface slide smoothly in the meshing and meshing contact without impact, and compensate for the size The smaller parallelism of the gear axis can also improve the noise caused by the transmission error due to the deformation of the gear teeth under load.

2. The control of gear error and tooth surface roughness in the manufacturing process focuses on controlling the tooth profile error, tooth pitch difference, tooth trajectory error and tooth surface roughness during the manufacturing process, so as to obtain the best gear in the process Comprehensive quality can greatly reduce the noise caused by gears.

3. The dynamic unbalance of the rotating part" The unbalance of the rotating body should be controlled within less than 6.6kg/(r/min). (4) Control of box center distance and bearing hole shape tolerance" Control box center distance With the tolerance of the bearing hole shape and position, it can reduce the noise generated by gear meshing.

Inverter is a kind of variable speed drive system software. It uses DC variable frequency drive technology to change the frequency and strength of Brake AC Gear Motors Company working standard voltage to smoothly control the speed and torque of AC motor. The most common one is that the input and output are all AC current. Communication/communication converter. The frequency converter has a wide range of applications, from small and medium-sized household appliances to large and medium-sized mine grinding equipment and refrigeration compressors. About 1/3 of the world's kinetic energy is consumed on motors that drive fixed-speed centrifugal water pumps, cooling fans and refrigeration compressors, and the market penetration rate of frequency converters is still not high. The obvious improvement of the high efficiency of electric energy is one of the key reasons for the application of frequency converters. With the continuous promotion of industrial automation, the application of frequency converters in the industrial production industry has become more and more common, and the maintenance and repair problems also seem to be increasingly critical.

Three elements for high-efficiency operation of frequency converters:
1. Common problems during normal operation
1. Is there any abnormal noise and vibration in the motor?
2. Whether the inverter and motor are hot and abnormal.
3. Is the working temperature too high?
4. Is the load current meter the same as the previous value?
5. Is the cooling fan of the inverter operating normally?
Note: The daily maintenance and repair of the inverter must be carried out in accordance with the product manual.

 2. Usual inspection matters
1. Check the refrigeration system and eliminate the dust in the air filter.
2. Check whether the standard parts on the inverter such as screws and anchor bolts are loose, and carry out the necessary tightening; check whether there are erosion, discoloration, cracks, damage, etc. Welding parts and riveting terminals, and check whether the frame shear wall is loose, whether the transmission lines and cables are damaged, etc.
3. Check whether the connection of the control circuit board is loose, whether the power capacitor is leaking, whether the line on the board is rusted or cracked, etc.
4. Check whether the coupling capacitor is leaking and whether the capacitor is reduced.
5. Check whether the grounding resistance is within the standard value range.
Note: It is suggested that regular maintenance should be carried out once a year.

3. Replacement of accessories
To make the frequency converter operate reliably for a long time, it is necessary to carry out maintenance on time for the service life of the electronic components in the frequency converter, and to dismantle and replace the key components of the frequency converter according to the service life.
1. The switching power supply of the cooling and cooling fan inverter is the most serious heating device. The heat generated during continuous operation must be discharged immediately. The damage of the centrifugal fan is not easy to warn and cannot be estimated. Therefore, the time must be removed and replaced. Because it's small and big. The service life of the general cooling fan is 10kh-40kh. According to the continuous operation of the inverter, the cooling fan should be removed and replaced once every 2 to 3 years, and the cooling fan for immediate cooling has the difference between the second and the third line. The first line of the second line cooling fan is the positive stage and the other line is the negative stage. In addition to the positive and negative stages of the three-wire cooling fan, there are also inspection stations. When disassembling and replacing, always pay attention to communication. The AC centrifugal fan is generally 220v, 380v point is 220v, and 380v point. The working voltage level of disassembly and replacement should not often fail. Reliable universality The well-known brand inverter power supply will have a professional maintenance chapter catalog in the hardware configuration guide, and the key initial use period, replacement cycle time, etc. will be marked internally. If there is no such content, it means that the inverter you purchased is not a well-known brand, and it is suggested to replace it.
2. Electrolytic capacitor The key passive components in the inverter, which are composed of inductors, capacitors, resistors, etc., are called filters. Its function is to get a special frequency or clear a special frequency. The volume size of the coupling capacitor is positively related to the amount of current in operation. In other words, the larger the amount of current in operation, the larger the volume of the necessary capacitor. The service life of power capacitors is generally 5 years. The volume of the capacitor should be regularly maintained once a year. Generally, it should be replaced when the volume is reduced by more than 20%.

DC motor brush device
(1) Armature core 　　The armature core is the main part of the main magnetic circuit and is used to embed the discharge armature winding. Generally, the armature core is laminated with punched sheets made of 0.5mm thick silicon steel sheets to reduce the eddy current loss and hysteresis loss in the armature core when the motor is running. The laminated core is fixed on the rotating shaft or the rotor support. An armature slot is opened on the outer circle of the iron core, and a discharge armature winding is embedded in the slot.
(2) Armature winding The function of armature winding is to generate electromagnetic torque and induced electromotive force. It is the key component of China Reversible AC Motors Suppliers for energy conversion, so it is called armature. It is made up of many coils connected according to a certain rule. The coils are made of high-strength enameled wire or glass-fiber-coated flat copper wire. The coil sides of different coils are embedded in the armature slot in two layers, between the coil and the iron core and on The coil sides of the lower two layers must be properly insulated. In order to prevent the centrifugal force from throwing the coil edge out of the slot, the terminal part of the coil extending out of the slot is bound with thermosetting non-lattice glass tape.
(3) Commutator In a DC motor, the commutator is equipped with brushes, which can convert the external DC power supply into the alternating current in the armature coil, so that the direction of the electromagnetic torque is constant; in the DC generator , The commutator is equipped with brushes, which can convert the alternating electromotive force induced in the armature coil into the direct current electromotive force drawn from the positive and negative brushes.
(4) Rotating shaft Rotating shaft plays a role of supporting the rotation of the rotor. It needs a certain degree of mechanical strength and rigidity, and is generally made of round steel. Excitation method of DC motor The excitation method of DC motor refers to the problem of how to supply power to the field winding and generate the magnetomotive force to establish the main magnetic field. According to different excitation methods, DC motors can be divided into the following types.
1 . Separately excited DC motor field winding and armature winding have no connection relationship, and the DC motor powered by other DC power supply to the field winding is called separately excited DC motor.
2 . Shunt-excited DC motor The field winding of the shunt-excited DC motor is connected in parallel with the armature winding. As a shunt generator, the terminal voltage from the motor itself supplies power to the field winding; as a shunt motor, the field winding and the electric The shaft shares the same power source, which is the same as a separately excited DC motor in terms of performance.
3. Series-excited DC motor The excitation winding of the series-excited DC motor is connected in series with the armature winding and then connected to the DC power supply. The excitation current of this DC motor is the armature current.
4. Compound Excitation DC Motor Compound Excitation DC Motor has two excitation windings: parallel excitation and series excitation. If the magnetomotive force generated by the series winding and the direction of the magnetomotive force generated by the parallel winding are the same, it is called product compound excitation. If the two magnetomotive forces have opposite directions, it is called differential compound excitation.