Techniques
1, in the operation of 200 ~ 300 hours, the first oil change should be carried out, in the subsequent use of the oil should be regularly checked the quality of the oil, for the mixing of impurities or deterioration of the oil must be replaced in a timely manner. In general, for long-term continuous operation of the reducer, according to the operation of 5000 hours or once a year to replace the new oil, long-term out of service reducer, before re-opening should also be replaced with new oil. Reducer should be added to the original grade of the same oil, not mixed with different grades of oil, the same grade and viscosity of different oils are allowed to mix;
2, oil change should wait until the reducer cooled down without the risk of combustion until, but still should be kept warm, because completely cooled down, the viscosity of the oil increases, the oil is difficult to drain. Note: To cut off the power supply of the transmission device to prevent unintentional energization;
3, work, when the oil temperature is found to rise above 80 ℃ or oil pool temperature exceeds 100 ℃ and produce abnormal noise and other phenomena should be discontinued, check the cause, must be eliminated, replace the lubricating oil before continuing to operate;
4, the user should have a reasonable use of the maintenance of rules and regulations, on the The user should have a reasonable use and maintenance rules and regulations on the operation of the reducer and the problems found in the inspection should be carefully recorded, the above provisions should be strictly enforced.
Maintenance
Selection of grease according to the walking reducer bearing load selection of grease, the heavy load should be selected for the small degree of penetration of the grease. When working under high pressure, in addition to the small degree of penetration, but also have a high oil film strength and extreme pressure function. When choosing grease according to the environment, calcium-based grease is not easy to dissolve in water and is suitable for dry and less water environment. When selecting grease according to the working temperature, the main indexes should be dropping point, oxidation stability and low temperature function. Dropping point can be used to evaluate the high temperature function, and the actual working temperature of the bearing should be lower than the dropping point by 10-20°C. Synthetic grease should be used at a temperature lower than the dropping point. The actual operating temperature of the bearing should be 10-20℃ below the dropping point. The operating temperature of synthetic grease should be 20-30℃ below the dropping point.
Different lubricants are prohibited from mixing with each other. The position of oil level screw, oil drain screw and ventilator is determined by the installation position.
Oil level check:
1. Cut off the power supply to prevent electric shock. Wait for the reducer to cool down;
2. Remove the oil level screw plug to check whether the oil is full;
3. Install the oil level screw plug.
Oil check:
1, cut off the power to prevent electric shock. Wait for the reducer to cool down;
2. Open the oil screw plug and take oil samples;
3. Check the viscosity index of the oil: if the oil is obviously turbid, it is recommended to replace it as soon as possible;
4. For the reducer with an oil level screw plug: check the oil level to see if it is qualified; install the oil level screw plug.
Oil replacement:
It is difficult to drain the oil after cooling as the viscosity of the oil increases, and the reducer should change the oil at the operating temperature.
1, cut off the power supply to prevent electric shock. Wait until the reducer cools down and there is no danger of burning;
Note: the reducer should still be kept warm when the oil is changed;
2. Put an oil catching tray under the oil drain screw;
3. Open the oil level screw, ventilator, and oil drain screw;
4. Exclude all the oil;
5. Put the oil drain screw;
6, Inject new oil of the same grade;
7, the oil volume should be consistent with the installation position;
8, check the oil level at the oil level screw plug;
9, tighten the oil level screw plug and ventilator.
Troubleshooting
Because of the harsh operating environment of the reducer, wear and tear, leakage and other faults often occur, the most important ones are:
1, reducer bearing chamber wear, including the shell bearing box, the housing bore bearing chamber, gearbox bearing chamber wear;
2, reducer gear shaft shaft diameter wear, the main wear parts in the head, keyway, etc.;
2, reducer gear shaft wear, wear parts in the keyway, the keyway, etc.;
2, reducer gear shaft wear.
3, reducer drive shaft bearing wear;
4, reducer bonding surface leakage.
For wear and tear, the traditional solution is to patch welding or brush plating after machining repair, but both have certain disadvantages: the thermal stress generated by the high temperature of the patch welding can not be completely eliminated, easy to cause damage to the material, resulting in bending or fracture of the parts; and brush plating by the thickness of the coating is limited to easy to flake off, and the above two methods are used to repair the metal metal, can not change the "hard to hard", "hard to hard", "hard to hard", "hard to hard". "Hard to hard" fit relationship, in the combined effect of the forces, will still cause wear and tear again. For some large bearing enterprises are unable to solve the problem on the spot, more to rely on outsourcing repair. Contemporary western countries for the above problems more use of polymer composite repair methods, which has a strong adhesive force, excellent compressive strength and other comprehensive performance. Application of polymer materials repair, can be free of disassembly free machining neither welding thermal stress, repair thickness is not limited, while the product has a metal material does not have the concessions, can absorb the impact of the equipment vibration, to avoid the possibility of wear and tear again, and greatly extend the service life of the equipment components, to save a lot of downtime for the enterprise, to create a great deal of economic value.
And for the leakage problem, the traditional method needs to disassemble and open the reducer, replace the sealing gasket or apply sealant, which is not only time-consuming and labor-intensive, but also difficult to ensure the sealing effect, and leakage will occur again in the operation. Polymer materials can be on-site management of leakage, the material has a superior adhesion, oil resistance and 350% of the tensile degree, to overcome the impact of vibration caused by the reducer, very good for the enterprise to solve the problem of reducer leakage.
Reason analysis of reducer oil leakage
1, reducer inside and outside the pressure difference: reducer operation process, friction of the moving parts of the friction heat as well as by the influence of the ambient temperature, so that the temperature of the reducer, if there is no ventilation holes or ventilation holes clogging, then the pressure within the machine is gradually increased, the higher the temperature inside the machine, the greater the pressure difference with the outside world, the lubricating oil in the pressure difference, leaking out from the crevice. The lubricant leaks out from the gap under the pressure difference.
2, reducer structural design unreasonable
1) check hole cover plate is too thin, tighten the bolt is easy to produce deformation, so that the bonding surface is not flat, from the contact gap oil leakage;
2) reducer manufacturing process, the casting is not annealed or aging treatment, not to eliminate the internal stresses, the inevitable deformation, resulting in gap, leading to leakage;
3) the box body There is no oil return groove, lubricating oil accumulates in the shaft seal, end cover, bonding surface, etc., under the action of differential pressure, leakage from the gap to the outside;
4) shaft seal structure design is unreasonable. Early reducer mostly used oil groove, felt ring type shaft seal structure, the assembly of the felt compression deformation, and the combined surface gap seal up. If the journal and seal contact is not ideal, due to the felt compensation performance is very poor, the seal will fail in a short time. Although the oil groove on the oil return hole, but it is very easy to block, the role of oil return is difficult to play.
3, too much refueling: reducer in the operation process, the oil pool is stirred up a lot, lubricating oil in the machine splash everywhere, if the refueling is too much, so that a large number of lubricating oil accumulated in the shaft seals, bonding surface, etc., resulting in leakage.
4, maintenance process is not appropriate: in the equipment maintenance, due to the combination of surface dirt removal is not complete, or sealant selection is not appropriate, sealing the direction of the installation of the opposite, do not replace the seals in a timely manner will also cause oil leakage.
Countermeasures against oil leakage of the reducer
1, improve the breathable cap and inspection hole cover: reducer pressure is greater than the outside atmospheric pressure is one of the main reasons for oil leakage, if you try to make the machine, outside the machine pressure equalization, oil leakage can be prevented. Although the reducer have breathable cap, but the breathable hole is too small, easy to be blocked by coal dust, oil, and each refueling have to open the inspection hole cover, open a time to increase the likelihood of oil leakage, so that the original leakage does not leakage also occurs in the place of leakage. To this end, a cup type breathable cap is produced, and the original thin inspection hole cover plate is changed to 6 mm thick, the cup type breathable cap is welded to the cover plate, the diameter of the breathable hole is 6 mm, which is easy to ventilate, and equalize the pressure, and when refueling from the oil cup, there is no need to open the inspection hole cover plate, which reduces the chances of oil leakage.
2, smooth flow: to be thrown by the gear bearing excess lubricant does not accumulate in the shaft seal, must make the excess lubricant along a certain direction to flow back to the pool, that is, to achieve smooth flow. Specific practice is in the center of the lower tile in the bearing seat to open a tilt to the machine back to the oil groove, at the same time in the end cap straight mouth also open a gap, the gap is right back to the oil groove, so that excess lubricating oil through the gap, back to the oil groove flow back to the oil pool.
3, improve the structure of the shaft seal
1) the output shaft for the half-axis reducer shaft seal improvement: belt conveyor, screw unloader, impeller coal feeder and most other equipment reducer output shaft for the half-axis, the transformation is more convenient. Disassemble the reducer, remove the coupling, take out the reducer shaft seal end cap, according to the matching skeleton oil seal size, in the original end cap outside the lathe machining groove, install the skeleton oil seal, with the spring side inward. Back to install, if the end cap is more than 35 mm from the inner end face of the coupling, you can install a spare oil seal on the shaft on the outside of the end cap, once the oil seal failure, you can take out the damaged oil seal, the spare oil seal will be pushed into the end cap, thus eliminating the need to dismantle the reducer, dismantle the coupling and other time-consuming and laborious processes.
2) Improvement of the shaft seal of the reducer whose output shaft is a complete shaft: there is no coupling for the output shaft of the reducer with complete shaft drive, and if it is transformed according to the 2.3.1 program, the workload is too big and impractical. In order to reduce the workload and simplify the installation procedure, a kind of dissectable end cover is designed and the open-ended oil seal is tried. Dissectable end cap outer lathe machining groove, when installing the oil seal, first take out the spring, the oil seal sawed off in the form of an opening, from the opening of the oil seal on the shaft, with adhesive to the opening of the butt, opening up, and then install the spring, push into the end cap can be.
4, the use of new sealing materials: for the reducer static sealing point leakage can be used for new polymer repair material sticky plug. If the reducer running static sealing point oil leakage, available surface engineering technology of the oil surface emergency repair agent sticky - polymer 25551 and 90T composite repair material to plug, so as to achieve the purpose of eliminating oil leakage.
5, conscientiously implement the overhaul process: in the reducer overhaul, to seriously implement the process procedures, the oil seal can not be installed in reverse, the lip should not be damaged, the outer edge should not be deformed, the spring can not be dislodged, the bonding surface should be cleaned up, the sealant coated with a uniform amount of refueling should not be more than the scale of the oil scale.
6, wipe: reducer static sealing point through the governance, generally can be achieved without seepage and leakage, but the dynamic sealing point due to aging seals, poor quality, improper assembly, shaft surface roughness and other reasons, so that the individual dynamic sealing point is still a small leakage, due to the poor working environment, the coal dust stuck to the shaft, it seems to be a piece of grease, so you need to stop the operation of the equipment after the shaft, wipe the oil.
Noise treatment
The noise generated by the reducer is mainly from the friction, vibration and collision of the transmission gear, how to effectively reduce and minimize the noise, so that it is more in line with the environmental requirements at home and abroad is also a key research topic. Reducing the noise of gear transmission during the operation of the reducer has become an important research topic in the industry, and many scholars at home and abroad have regarded the change of the meshing stiffness of the gear teeth in gear transmission as the main factor of the gear dynamic load, vibration and noise. With the method of repairing the shape, the dynamic load and speed fluctuations are minimized to achieve the purpose of reducing noise. This method is proved to be a more effective method in practice. But with this method, the process needs to have trimming equipment, the majority of small and medium-sized factories often can not be implemented.
After many years of research, proposed by optimizing the gear parameters, such as displacement coefficient, tooth height coefficient, pressure angle, center distance, so that the meshing impact speed is reduced to a minimum, the meshing impact speed and meshing impact speed ratio is in a certain numerical value range, to reduce or avoid meshing pitch circle impact of the gear design method, but also can significantly reduce the gear noise reducer. For the noise problem of the reducer, you can also Maitre Super Sealant or lubricant, which is an excellent gearbox additive that can form a film of inert material on the components, thus reducing friction, gear noise, and leakage.
Installation method
In the family of gearboxes, planetary gearboxes are used in servo, stepper, DC and other transmission systems because of their small size, wide range of deceleration, high precision and many other points. Its role is to ensure precision transmission, mainly used to reduce the speed to increase torque and reduce the load / motor ratio of inertia. In the past few years, some users have broken the output shaft of the reducer due to human factors such as illegal installation when using the reducer, causing unnecessary losses to the enterprise. Therefore, in order to better help the majority of users with a good reducer, to introduce you in detail how to correctly install the planetary reducer.
Correct installation and use of the reducer is an important part of the normal operation of mechanical equipment. Therefore, when installing the planetary gearbox, please be sure to strictly follow the following installation and use related matters, assembly and use carefully.
First step
Confirm that the motor and gearhead are intact before installation, and strictly check whether the dimensions of the parts connected to the motor and the gearhead are matched, here are the dimensions and fit tolerances of the motor's locating cams, the input shaft and the gearhead's grooves, and so on.
Step 2
Screw off the screws on the dustproof holes on the outside of the gearhead flange, adjust the PCS system clamping ring so that its side holes are aligned with the dustproof holes, and insert the hexagonal screw. After that, remove the motor shaft key.
Step 3
Connect the motor to the gearhead naturally. When connecting, you must ensure that the output shaft of the gearhead and the input shaft of the motor have the same concentricity and the outer flanges of both are parallel. If the concentricity is not the same, it will cause the motor shaft to break or the reducer gear to wear out. In addition, when installing, it is strictly prohibited to hit with hammers, etc. to prevent axial or radial force from damaging the bearings or gears. Be sure to tighten the mounting bolts before tightening the tightening bolts. Before installation, wipe the antirust oil on the motor input shaft, positioning cam and reducer connection parts with gasoline or zinc-sodium water. The purpose is to ensure the tightness of the connection and the flexibility of operation, and to prevent unnecessary wear and tear.
Before connecting the motor to the gearhead, the motor shaft keyway should be perpendicular to the tightening bolt. In order to ensure uniform force, first screw on any diagonal mounting bolts, but do not tighten, and then screw on the other two diagonal mounting bolts and finally tighten the four mounting bolts one by one. Finally, tighten the tightening bolts. All tightening bolts should be fixed and checked with a torque plate hand in accordance with the indicated fixing torque data. The correct installation between the speed reducer and mechanical equipment is similar to the correct installation between the speed reducer and the drive motor. The key is to ensure that the output shaft of the reducer and the drive part of the shaft concentricity.
1, reducer and working machine connection: reducer directly suited to the main shaft of the working machine, when the reducer is running, the role of the reaction torque on the reducer case, and mounted on the reducer case of the reaction torque bracket or by other methods to balance. The shaft sleeve at the coupling end of the countermoment bracket and the fixed support uses rubber and other elastomers to prevent deflection and absorb the resulting torque fluctuations;
3. Installation relationship between the speed reducer and the working machine: in order to avoid deflection of the working machine's main shaft and additional force on the speed reducer bearings, the distance between the speed reducer and the working machine should be as small as possible without affecting the normal working conditions, and the value is 5-10mm.
4.
Correct installation, use and maintenance of the reducer is to ensure the normal operation of mechanical equipment is an important part.
1, when installing the reducer, should pay attention to the transmission center axis alignment, the error shall not be greater than the use of the coupling compensation. Good alignment can prolong the service life and obtain ideal transmission efficiency;
2, when installing the transmission parts on the output shaft, it is not allowed to use a hammer to knock, usually use the assembly fixture and internal threads at the end of the shaft, and use the bolts to press the transmission parts into it, otherwise it may cause damage to the internal parts of the reducer. It is best not to use steel fixed coupling, because this type of coupling is not installed properly, it will cause unnecessary external load, so as to cause early damage to the bearings, and in serious cases, even cause the output shaft fracture;
3, the reducer should be securely mounted on a stable level of the foundation or base, the oil discharge tank should be able to remove the oil, and the cooling air circulation is fluent. Unreliable foundation, operation will cause vibration and noise, and promote bearing and gear damage. When the transmission joints have protruding objects or gear, sprocket transmission, should consider adding protective devices, the output shaft is subjected to large radial load, should be used to strengthen the type;
4, according to the specified installation device to ensure that the staff can be conveniently close to the oil markers, ventilation plugs, oil drain plugs. After installation in place, should be in order to fully check the accuracy of the installation position, the reliability of the fasteners compression, the installation should be able to rotate flexibly. The speed reducer adopts oil pool splash lubrication, and the user needs to remove the screw plug of the vent hole and replace it with the vent plug before operation. According to different installation position, and open the oil level plug screw to check the height of the oil level line, refueling from the oil level plug until the lubricant overflows from the oil level plug screw hole, screw on the oil level plug to make sure that there is no error, then you can carry out the no-load test run for a period of time of not less than 2 hours. Operation should be smooth, no impact, vibration, noise and oil leakage phenomenon, found abnormalities should be excluded in a timely manner.
After a certain period of time should check the oil level again to prevent possible leakage caused by the casing, such as the ambient temperature is too high or too low, you can change the lubricant grade.
Model selection
Select a ratio as close as possible to the ideal:
Ratio = servo motor speed / speed of the output shaft of the reducer
Torque calculation: Torque calculation is very important for the life of the reducer, and it is important to pay attention to the maximum acceleration of the value of the torque (TP), whether or not it exceeds the maximum load torque of the reducer.
Applicable power is usually the applicable power of the servo type on the market, the applicability of the reducer is very high, the coefficient of operation can be maintained at more than 1.2, but in the selection of their own needs to decide:
The main points are two:
1, the selection of servo motors can not be greater than the maximum use of servo motor axial diameter on the form;
2, if by the Torque calculation work, the speed can meet the usual operation, but in the servo full output, there is a shortage of phenomena, can be in the motor side of the driver, to do current-limiting control, or in the mechanical axis to do the torque protection, which is very necessary.
The selection of general-purpose gearboxes includes the steps of proposing original conditions, selecting types, and determining specifications.
In contrast, the type selection is relatively simple, and accurately provide the working conditions of the reducer, grasp the design, manufacture and use of the reducer characteristics is the key to the correct and reasonable selection of general-purpose reducer specifications.
Specification selection to meet the strength, thermal balance, shaft extension part of the radial load and other conditions.
Selection of specifications:
The biggest difference between general-purpose reducer and special reducer design and selection method is that the former applies to various industries, but the speed reduction can only be designed according to a specific working conditions, so the selection of the user needs to be considered according to their respective requirements of the different correction factors, the factory should be based on the actual selection of the motor power (not the rated power of the reducer); the latter is based on user-specific conditions design, the coefficient to be considered. Specialized conditions design, the coefficient of consideration, the design of the general has been taken into account, as long as the selection to meet the use of power less than or equal to the rated power of the reducer can be, the method is relatively simple.
The rated power of general-purpose reducer is generally calculated according to the use (working condition) coefficient KA=1 (motor or turbine as the prime mover, the working machine load is smooth, working 3~10h per day, the number of startups per hour is ≤5, and the allowable startup torque is 2 times of the working torque), the safety coefficient of contact strength SH ≈1, and the probability of failure for a single pair of gears is ≈1%, and other conditions are calculated to determine the power rating of general-purpose reducer.
The rated power of the selected speed reducer should satisfy
PC=P2KAKSKR≤PN
In which PC-calculated power (KW);
PN-rated power of the speed reducer (KW);
P2 - the power of the working machine (KW);
KA - the use coefficient, taking into account the influence of the use of working conditions;
KS - the -starting coefficient, considering the effect of the number of starts;
KR - reliability coefficient, considering different reliability requirements.
The use coefficients used around the world are essentially the same. Although many samples do not reflect the two coefficients of KS\KR, but because of know yourself (clear requirements of their own working conditions), know each other (clear performance characteristics of the reducer), foreign selection are generally left with a large margin, equivalent to the impact of the KR\KS has been taken into account.
Because of the use of different occasions, different degrees of importance, damage to personal safety and production losses caused by different sizes, different maintenance difficulties, and thus the reliability of the speed reducer requirements are not the same. Coefficient KR is the actual need for the reliability of the original design of the reliability of the correction. It is in line with ISO6336, GB3480 and AGMA2001-B88 (American Gear Manufacturers Association standard) on the gear strength calculation method. Some domestic users of the reliability of the gear reducer has not been able to mention the specific amount of requirements, according to the general design provisions of the special reducer (SH ≥ 1.25, the probability of failure ≤ 1/1000), the more important occasions to take KR = 1.25 = 1.56 or so.
Thermal balance check:
General reducer permissible thermal power value is in specific conditions (general ambient temperature of 20 ℃, 100% per hour, continuous operation, power utilization of 100%), according to the lubricating oil allowed to determine the maximum equilibrium temperature (generally 85 ℃).
Conditions vary according to the corresponding coefficients (sometimes combined into a coefficient) for correction.
Selected reducer should meet
PCt = P2KTKWKP ≤ Pt
In the formula PCt - calculated thermal power (KW);
KT - ambient temperature coefficient;
KW - operation cycle coefficient;
KP - power utilization coefficient;
Pt - permissible thermal power of the reducer (KW).
Check the shaft load:
General-purpose speed reducer is often required to input shaft, output shaft extension of the middle part of the maximum radial load allowed to withstand to give the limit should be checked, more than should be put forward to the manufacturer to thicken the diameter of the shaft and increase the requirements of bearings and so on.
Lubrication and maintenance
Before putting into operation, the reducer is filled with grease of the recommended type and value. The speed reducer is lubricated with lubricating oil. For vertically mounted gearboxes, additional lubrication measures are used in view of the fact that the lubricant may not ensure reliable lubrication of the uppermost bearing.
Prior to operation, the reducer is filled with an appropriate amount of lubricant. Reduction gears are usually equipped with an oil fill hole and an oil drain plug. The mounting position must therefore be specified when ordering the gearbox.
The temperature of the operating oil must not exceed 80℃.
Combined gearheads with lifetime lubrication are filled with synthetic oil at the manufacturer's factory; otherwise, the gearheads are usually supplied without lubricant and with an oil filler and drain plug. The lubricant quantities for gearheads listed in this catalog are estimates only. Set the position of the oil level plug according to the mounting position specified at the time of ordering to ensure correct oil filling. The amount of oil filled into the gearhead should be determined according to the different mounting methods. If the transmitted power exceeds the thermal capacity of the gearhead, an external cooling device must be provided.