The reducer is a mechanical transmission device in many fields, the industry involves product categories including various types of gear reducers, planetary gear reducers and worm gear reducers, but also includes a variety of special transmission devices, such as speed increasing devices, speed control devices, and various types of composite transmission devices, including flexible transmission devices. Our products are used in metallurgy, non-ferrous metals, coal, building materials, ships, water conservancy, electric power, engineering machinery and petrochemical industries.
Speed reducer products have a wide range of applications. Food and light industry, electric power machinery, construction machinery, metallurgical machinery, cement machinery, environmental protection machinery, electronic appliances, road construction machinery, water conservancy machinery, chemical machinery, mining machinery, conveying machinery, building materials machinery, rubber machinery, petroleum machinery and other industry sectors have a strong demand for reducer products.
After 200~300 hours of operation, the first oil change should be carried out, and the quality of oil should be checked regularly in the future use, and the oil mixed with impurities or deteriorated should be replaced in time. In general, for long-term continuous work of the reducer, according to the operation of 5000 hours or once a year to replace the new oil, long-term disuse of the reducer, before re-running should also be replaced with new oil. The reducer should be added to the same grade of oil as the original, not mixed with different grades of oil, the same grade and different viscosity of oil allowed to be mixed.
2. Oil change should wait until the reducer cools down without the risk of burning, but still should be kept warm, because after complete cooling, the viscosity of the oil increases, and it is difficult to drain the oil. Note: To cut off the power supply of the transmission to prevent unintentional energization.
3 . Work, when found that the oil temperature temperature rise more than 80 ℃ or oil pool temperature more than 100 ℃ and produce abnormal noise and other phenomena should stop using, check the cause, must troubleshoot, replace the lubricant before continuing to run;.
4. The user should have a reasonable use of maintenance rules and regulations, the operation of the reducer and the problems found in the inspection should be carefully recorded, the above provisions should be strictly enforced.
Grease selection according to the walking reducer bearing load selection of grease, the heavy load should choose a small needle into the grease. When working under high pressure, in addition to small needle penetration, it should also have high oil film strength and extreme pressure function. Calcium-based grease has good water resistance and is not easy to emulsify and deteriorate through water, so it can be used for lubrication of various mechanical parts in wet environment or in contact with water. According to the working temperature selection grease, the main index should be the dropping point, oxidation stability and low temperature function, dropping point is generally used to evaluate the high temperature function, bearing the actual working temperature should be lower than the dropping point 10-20 ℃. The use temperature of synthetic grease should be lower than the drop point 20-30℃.
Different lubricants are prohibited to be mixed with each other. The position of oil level screw plug, oil drain screw plug and ventilator is determined by the installation position.
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 if the oil is full.
3. Install the oil level screw plug.
Cut off the power to prevent electric shock. Wait for the reducer to cool down.
2. Open the oil screw plug and take oil sample.
3. Check the viscosity index of the oil: if the oil is obviously cloudy, it is recommended to replace it as soon as possible.
4. For the reducer with oil level screw plug: check the oil level and whether it is qualified; install the oil level screw plug.
The viscosity of the oil increases after cooling oil drainage difficulties, reducer should be changed at operating temperature.
1. Cut off the power supply to prevent electric shock. Wait until the reducer cools down without the risk of combustion.
Note: the reducer should still be kept warm during the oil change.
2. Put an oil catch pan under the oil drain screw plug.
3. Open the oil level screw plug, ventilator and oil drain screw plug.
4. Exclude all the oil.
5. put on the oil drain screw.
6. Inject new oil of the same grade.
7. The amount of oil 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.
Due to the harsh operating environment of the reducer, there are often wear and tear, leakage and other failures, the most important ones are.
reducer bearing chamber wear, which also includes the shell bearing box, box bore bearing chamber, gearbox bearing chamber wear.
2. reducer gear shaft shaft diameter wear, the main wear parts in the shaft head, keyway, etc..
3. reducer drive shaft bearing position wear.
4. Leakage of the combination surface of the reducer.
For the wear problem, the traditional solution is to repair the welding or brushing after machining, but both have certain disadvantages: the heat stress generated by high temperature welding can not be completely eliminated, easy to cause material damage, resulting in bending or fracture of the parts; and brush plating by the coating thickness, easy to flake, and the above two methods are used to repair metal metal, can not change the “hard to hard “fit relationship, under the combined action of the forces, will still cause re-wear. For some large bearing enterprises is unable to solve the site, more to rely on outsourcing repair. Contemporary Western countries for the above problems more use polymer composite repair method, which has a super strong adhesion, excellent compressive strength and other comprehensive performance. The application of polymer materials repair, free of disassembly and free of machining both no welding heat stress impact, repair thickness is not limited, while the product does not have the metal material concession, can absorb the impact vibration of the equipment, to avoid the possibility of re-wear, and greatly extend the service life of equipment components, save a lot of downtime for enterprises, creating huge economic value.
For the leakage problem, the traditional method needs to disassemble and open the reducer and then replace the sealing gasket or apply sealant, which is not only time-consuming and laborious, but also difficult to ensure the sealing effect, and the leakage will appear again in operation. The polymer material can cure the leakage on site, and the material has superior adhesion, oil resistance and 350% stretching degree to overcome the influence caused by the vibration of the reducer, which is a good solution to the leakage problem of the reducer for the enterprise.
Reducer inside and outside the pressure difference: reducer operation process, the motion vice friction heating and by the influence of the ambient temperature, so that the temperature of the reducer rises, if there is no air permeability hole or air permeability hole blockage, the pressure inside the machine gradually increased, the higher the temperature inside the machine, the greater the pressure difference with the outside world, the lubricant under the action of pressure difference, from the gap leakage.
2. The structure design of reducer is not reasonable
(1) The inspection hole cover plate is too thin, and it is easy to produce deformation after tightening the bolts, so that the combination surface is not flat and oil leaks from the contact gap.
(2) Reducer manufacturing process, the casting is not annealed or aging treatment, not to eliminate internal stress, deformation is bound to occur, resulting in gaps, resulting in leakage.
(3) There is no oil return groove on the box, and the lubricating oil accumulates in the shaft seal, end cover, bonding surface, etc., and leaks outward from the gap under the action of pressure difference.
4) The structure of shaft seal is not designed reasonably. Early reducer mostly adopts oil groove, felt ring type shaft seal structure, when assembled so that the felt is compressed to produce deformation, and the gaps of the bonding surface are sealed up. If the contact between the journal and the seal is not ideal, the seal will fail in a short time due to the poor compensation performance of the felt. Although there are oil return holes on the oil groove, but it is very easy to block, it is difficult to play the role of oil return.
3. Too much refueling: reducer in the process of operation, the oil pool is churned, the lubricant splashed everywhere in the machine, if too much refueling, so that a large amount of lubricant accumulates in the shaft seal, bonding surface, etc., resulting in leakage.
4. Improper maintenance process: In the equipment maintenance, due to the combination of surface dirt removal is not complete, or improper selection of sealant, seal direction installed in reverse, not timely replacement of seals, etc. will also cause oil leakage.
Control reducer oil leakage countermeasures
Improve the air permeable cap and inspection hole cover: reducer internal pressure is greater than the external atmospheric pressure is one of the main reasons for oil leakage, if you try to make the pressure inside the machine, the machine outside the pressure balance, oil leakage can be prevented. Although the speed reducer has a breathable cap, but the ventilation hole is too small, easy to be clogged by coal dust, oil, and each time to open the inspection hole cover, open once to increase the possibility of oil leakage, so that the original place does not leak also occurred. For this reason, an oil cup type ventilation cap is made, and the original thin inspection hole cover plate is changed to 6 mm thick, and the oil cup type ventilation cap is welded on the cover plate, and the diameter of the ventilation hole is 6 mm, which is easy to ventilate and realize the equal pressure, and the oil is added from the oil cup when refueling, without opening the inspection hole cover plate, which reduces the chance of oil leakage.
2. Smooth flow: To make the excess lubricating oil dumped on the bearing by the gear not accumulate at the shaft seal, the excess lubricating oil must flow back to the oil pool in a certain direction, that is, to achieve smooth flow. The specific practice is to open an oil return groove in the center of the lower tile of the bearing seat which is inclined to the machine, and also open a gap at the straight mouth of the end cover, and the gap is facing the oil return groove, so that the excess lubricating oil flows back to the oil pool through the gap and the oil return groove.
3. Improve shaft seal structure
1）Improve the shaft seal of the reducer whose output shaft is half-shaft: The output shaft of the reducer of most equipment such as belt conveyor, screw unloader, impeller coal feeder is half-shaft, which is more convenient for transformation. Disassemble the reducer, remove the coupling, take out the end cover of the reducer shaft seal, turn the groove on the outside of the original end cover according to the size of the matching skeleton oil seal, and install the skeleton oil seal, with the spring side inward. If the end cover is more than 35 mm away from the inner end of the coupling, a spare oil seal can be installed on the shaft outside the end cover. Once the oil seal fails, the damaged oil seal can be removed and the spare oil seal can be pushed into the end cover, thus eliminating the time-consuming and laborious process of disassembling the reducer and dismantling the coupling.
(2) The output shaft is the whole shaft of the reducer shaft seal improvement: the whole shaft drive reducer output shaft without coupling, if in accordance with 2.3.1 program transformation, the workload is too large and impractical. In order to reduce the workload and simplify the installation procedure, a dissectable end cover was designed and an open type oil seal was tried. The outer side of the splittable end cover is turned into a groove, and when installing the oil seal, the spring is taken out first, the oil seal is sawed off in the shape of an opening, and the oil seal is set on the shaft from the opening, and the opening is docked with adhesive with the opening upward, and then the spring is installed and pushed into the end cover.
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. Carefully implement the overhaul process: In the reducer overhaul, carefully implement the process procedures, the oil seal must not be installed backwards, the lip should not be damaged, the outer edge should not be deformed, the spring should not fall off, the combined surface should be cleaned, the sealant is applied evenly, and the amount of oil should not exceed the scale of the oil scale.
6. Wipe: reducer static sealing point through the governance, generally can achieve no seepage not leakage, but the dynamic sealing point due to aging seals, poor quality, improper assembly, shaft surface roughness and other reasons, making individual dynamic sealing point still has a small leakage, due to poor working environment, coal dust sticking to the shaft, appears oily, so the need to stop running the equipment, wipe the oil on the shaft.
The noise of the reducer is mainly from the friction, vibration and collision of the transmission gear, how to effectively reduce and reduce the noise, so that it is more in line with the requirements of environmental protection is also a key research topic at home and abroad. Many scholars at home and abroad regard the change of gear tooth mesh stiffness in gear transmission as the main factor of gear dynamic load, vibration and noise. With the method of shaping, the dynamic load and speed fluctuations are minimized to achieve the purpose of reducing noise. This method has proven to be a more effective method in practice. But with this method, the process needs to have shaping equipment, the majority of small and medium-sized factories often can not be implemented.
After years of research, the gear design method of reducing or avoiding meshing pitch impact by optimizing gear parameters, such as displacement coefficient, tooth height coefficient, pressure angle, center distance, so that the meshing impact speed is reduced to a minimum and the ratio of meshing out impact speed to meshing in impact speed is in a certain value range, can also significantly reduce gear noise of reducer. For gearbox noise problems, you can also Metrolite 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.
Among the family of gearboxes, planetary gearboxes are used in servo, stepper, DC and other transmission systems for their small size, wide reduction range and high accuracy. Its role is to ensure precision transmission, mainly used to reduce the speed to increase torque and reduce the load/motor rotational inertia ratio. In the past few years, some users in the use of reducer, due to illegal installation and other human factors, and the output shaft of the reducer broke, so that the enterprise suffered unnecessary losses. Therefore, in order to better help the majority of users with the reducer, to introduce to you in detail how to correctly install the planetary reducer.
Correct installation and use of the reducer is an important part of ensuring the normal operation of machinery and equipment. Therefore, when installing the planetary reducer, please be sure to strictly follow the following installation and use related matters, and carefully assemble and use.
Step 1
Confirm that the motor and reducer are intact before installation, and strictly check whether the dimensions of the parts connected to the motor and reducer match, here are the dimensions and fitting tolerances of the motor’s positioning boss, input shaft and reducer recess, etc.
Step 2
Unscrew the screw on the dustproof hole on the outside of the reducer flange, adjust the PCS system clamping ring so that its side hole is aligned with the dustproof hole, and insert the hexagonal screw. After that, take away the motor shaft key.
Step 3
Connect the motor to the reducer naturally. When connecting, you must ensure that the output shaft of the reducer and the input shaft of the motor are concentric and the outer flange of the two are parallel. If the concentricity is not consistent, it will lead to motor shaft breakage or gear wear of the reducer. In addition, during installation, it is strictly forbidden to hit with hammers, etc. to prevent excessive axial or radial forces 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 tab and reducer connection parts with gasoline or sodium zinc water. The purpose is to ensure the tightness of the connection and the flexibility of the operation, and to prevent unnecessary wear.
Before connecting the motor to the reducer, the motor shaft keyway should be perpendicular to the tightening bolt. In order to ensure uniform force, screw the mounting bolts at any diagonal position first, but do not screw them tightly, then screw the other two mounting bolts at diagonal positions and finally screw the four mounting bolts one by one. Finally, screw the tightening bolts. All tightening bolts should be fixed and checked by torque plate hand according to the fixed torque data indicated. The correct installation between the reducer and the mechanical equipment is similar to the correct installation between the reducer and the drive motor. The key is to ensure that the output shaft of the reducer and the driven part of the shaft concentricity consistent.
Reducer and work machine coupling: reducer directly set in the work machine spindle, when the reducer operation, the role in the reducer box on the reaction torque, and installed in the reducer box on the reaction torque bracket or by other methods to balance. machine is directly matched, the other end is coupled with the fixed bracket.
2. Installation of reaction moment bracket: The reaction moment bracket should be installed on the side of the reducer facing the working machine to reduce the bending moment attached to the shaft of the working machine. The bushings of the reaction moment bracket and the fixed support coupling end use rubber and other elastomers to prevent deflection and absorb the torque fluctuations generated.
3. Reducer and work machine installation relationship: in order to avoid the work machine spindle deflection and additional force on the reducer bearing, the distance between the reducer and the work machine, without affecting the normal working conditions should be as small as possible, the value of 5-10mm.
Correct installation, use and maintenance of the reducer is an important link to ensure the normal operation of machinery and equipment.
1. when installing the reducer, should pay attention to the transmission center axis alignment, the error shall not be greater than the use of couplings used to compensate for the amount. Good alignment can extend the service life and obtain the ideal transmission efficiency.
2. When installing the transmission parts on the output shaft, hammering is not allowed, usually using the assembly jig and the internal threads of the shaft end, and pressing the transmission parts in with bolts, 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 properly installed, will cause unnecessary applied load, resulting in early damage to the bearing, and in serious cases even cause the output shaft fracture;.
3. The reducer should be firmly installed on a stable horizontal foundation or base, the oil drainage tank should be able to remove the oil, and cooling air circulation smooth. The foundation is not reliable, the operation will cause vibration and noise, and prompt bearing and gear damage. When the transmission coupling has protrusions or using gears, sprockets transmission, should consider the addition of protective devices, the output shaft to bear a large radial load, should be selected to strengthen the type.
4. According to the specified installation device to ensure that the staff can easily approach the oil mark, ventilation plug, oil drain plug. After installation in place, the accuracy of the installation position should be fully checked in order, the reliability of each fastener compression, and should be able to rotate flexibly after installation. The 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 the different installation position, and open the oil level plug screw to check the height of the oil level line, from the oil level plug at the refueling until the lubricant from the oil level plug screw hole overflow, screw on the oil level plug to determine the correct, before the no-load test run, the time should not be less than 2 hours. Operation should be smooth, no shock, vibration, noise and oil leakage phenomenon, found abnormal should be promptly excluded.
After a certain period of time, the oil level should be checked again to prevent possible leakage caused by the housing, such as when the ambient temperature is too high or too low, the brand of lubricant can be changed.
As close to the ideal reduction ratio as possible: reduction ratio = servo motor speed/reducer output shaft speed. Torque calculation: for the life of the reducer, torque calculation is very important, and pay attention to the maximum torque value of acceleration (TP), whether it exceeds the maximum load torque of the reducer.
Applicable power is usually the applicable power of the servo machine on the market, the applicability of the reducer is very high, the work coefficient can be maintained at more than 1.2, but in the choice can also be determined by their own needs, the main points are two.
1. The choice of servo motor output axis diameter can not be greater than the maximum use of axis diameter on the form.
2. If the torque calculation work, the speed can meet the usual operation, but in the servo full output, there is a shortage of phenomenon, you can do in the motor side of the drive, current limit control, or in the mechanical axis to do torque protection, which is very necessary.
The selection of general-purpose reducer includes the steps of proposing the original conditions, selecting the type, and determining the specifications. In comparison, type selection is relatively simple, while providing accurate working conditions of the reducer and mastering the design, manufacturing and use characteristics of the reducer are the keys to the correct and reasonable selection of specifications for the universal reducer. The specification selection should meet the conditions of strength, thermal balance, and radial load on the shaft extension part.
The biggest difference between general-purpose reducer and special reducer design selection method is that the former is applicable to various industries, but the reducer can only be designed according to a specific working condition, so the user needs to consider different correction coefficients when selecting according to their respective requirements, the factory should be selected according to the actual motor power (not the rated power of the reducer); the latter is designed according to the user’s special conditions, the coefficients to be considered, the design has generally been made to consider, the selection as long as to meet the use of power less than or equal to the rated power of the reducer, the method is relatively simple.
The rated power of the general-purpose reducer is generally calculated according to the use (working condition) coefficient KA = 1 (motor or turbine as the prime mover, smooth load of the working machine, 3~10h per day, ≤5 times per hour starting, the allowable starting torque is 2 times of the working torque), the contact strength safety factor SH ≈ 1, the probability of failure of a single pair of gears ≈ 1%, and other conditions to determine.
The rated power of the selected reducer should meet
PC=P2×KA×KS×KR≤PN
where PC – calculated power (KW).
PN – the rated power of the reducer (KW)
P2-working machine power (KW).
KA-use coefficient, considering the influence of use conditions
KS-starting coefficient, considering the influence of the number of starts.
KR-Reliability coefficient, considering different reliability requirements.
The usage coefficients used in all countries of the world are basically the same. Although many samples do not reflect the two coefficients of KSKR, but because of knowing oneself (clear about the requirements of their own working conditions) and knowing the other (clear about the performance characteristics of the reducer), foreign selection is generally left with a large amount of affluence, equivalent to the influence of KRKS has been considered.
Due to the different occasions of use, different degrees of importance, different sizes of damage to personal safety and production losses, and different ease of maintenance, the requirements for the reliability of the reducer are different. Coefficient KR is the actual reliability required to correct the reliability of the original design. It conforms to the provisions of ISO6336, GB3480 and AGMA2001-B88 (American Gear Manufacturers Association standard) for gear strength calculation method. Some domestic users can not yet mention the specific amount of the reliability of the reducer requirements, can be in accordance with the general special reducer design provisions (SH ≥ 1.25, probability of failure ≤ 1/1000), the more important occasions to take KR = 1.25 = 1.56 or so.
The permissible thermal power value of the general-purpose reducer is determined under specific working conditions (general ambient temperature 20℃, 100% per hour, continuous operation, 100% power utilization) according to the maximum equilibrium temperature allowed for the lubricant (generally 85℃).
The conditions vary and are corrected by the corresponding coefficient (sometimes combined into a single coefficient).
The selected reducer should meet
PCt=P2×KT×KW×KP≤Pt
where PCt – calculated thermal power (KW).
KT-ambient temperature coefficient.
KW-operation cycle coefficient.
KP-power utilization coefficient.
Pt-permitted thermal power of reducer (KW).
Calibration of shaft load.
General-purpose reducer is often required to give restrictions on the maximum radial load allowed in the middle part of the input shaft and output shaft extension, which should be calibrated, and when exceeded, the manufacturer should be requested to thicken the shaft diameter and increase the bearing, etc.
Lubrication maintenance
Before putting into operation, put the recommended type and value of grease into the reducer. The reducer is lubricated with lubricating oil. For vertically mounted speed reducers, additional lubrication measures are used in view of the fact that lubricating oil may not ensure reliable lubrication of the uppermost bearing.
Prior to operation, the reducer is filled with the appropriate amount of lubricant. Gearboxes are usually equipped with oil filling holes and oil drain plugs. The installation position must therefore be specified when ordering the gearbox.
The operating oil temperature must not exceed 80°C.
The combination gearboxes with lifetime lubrication are filled with synthetic oil at the manufacturer, otherwise the gearboxes are usually supplied without oil and with oil fill and drain plugs. The quantity of lubricating oil for the gearboxes listed in this catalogue is only an estimate. Set the position of the oil level plugs according to the installation position specified at the time of order to ensure proper oil filling, and the amount of oil to be filled in the gearbox should be determined according to the different installation methods. If the transmission power exceeds the thermal capacity of the reducer, an external cooling device must be provided.
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