1. Introduction
Before installation and use, please read this manual carefully. The gearbox was subjected to no-load testing before leaving the factory, and the load testing was carried out in accordance with the contract requirements.
At the time of shipment, the gearbox oil was drained and packaging was carried out in accordance with the contract. Unless otherwise specified in the contract (such as if the customer requests assistance with installation), any actions taken with the gearbox after it leaves the factory exceed the control of our factory.
Therefore, this manual particularly emphasizes and clarifies the following user responsibilities:
● Transport
● Storage and corrosion prevention
● Installation
● Expired storage
● Disassembly
● Checks before start
● Operation and maintenance
two . Unpacking
During the unpacking process, check that the product model and specifications are correct; check that all components and accessories are included and that the technical documentation is complete.
Inspect for damage or rust that may have occurred during transportation or storage. (If damage or rust is discovered, determine its cause and proceed with repairs. The quality of repairs must be mutually approved by the manufacturer and user before the product can be used.)
3. Technical Specifications
3.1 Identification plate
All crucial technical parameters are incorporated into the nameplate, which predominantly includes the following details:
1 gearbox model: FD3300C
2 Power: 3300KW
3 gear ratio: 94.972
4 Input speed: 12.6 rpm
5 Output speed: 1200 rpm
6 Weight: 29500Kg
3.2 Field of Application
This gearbox is exclusively for wind turbine applications. Its design and manufacturing process strictly comply with the load and conditions described in the technical specifications provided by the customer.
The gearbox manufacturer is not responsible for any problems that may arise from use outside these conditions. Any modifications made without the manufacturer's consent will not be accepted.
4. Safety Precautions
During transportation, lifting, installation, adjustment and use, all local government safety requirements must be strictly followed and relevant protective measures must be implemented.
4.1 Regular use
4.1.1 The use and maintenance of the gearbox must comply with the terms of the contract and must be approved by Nan High Gear.
4.1.2 No change in the use of the reducer and its components will be accepted, strict compliance is necessary to avoid dangerous operations.
4.2 Customer Obligations
4.2.1 Customers must ensure that all relevant personnel, including those involved in installation, adjustment, maintenance, transportation and storage, carefully read this manual before work and strictly follow the instructions during work to avoid injury, damage to the gears and environmental pollution caused by improper operations.
4.2.2 In the process of transportation, ground mounting, installation, adjustment and maintenance of the gearbox, it is essential to comply with relevant safety standards and environmental protection requirements.
4.2.3 Only experienced professionals with relevant training should install, adjust and maintain the reducer.
4.2.4 High pressure equipment must not be used to clean the reducer.
4.2.5 Great care must be taken in all connection tasks and relevant safety guidelines must be strictly followed.
4.2.6 Before any maintenance work on the gearbox, ensure that the gearbox and fan are switched off and that appropriate safety signs are present to indicate the current status of the fan and gearbox.
4.2.7 Any welding activity on the reducer itself is expressly prohibited. During welding operations, the reducer must not serve as a ground wire, and it must be ensured that other welding activities do not damage the gears and bearings.
4.2.8 If there is any alarm alert, such as excessive temperature, overpressure or the need to immediately disconnect the fan, immediate measures must be taken.
4.2.9 The reducer may only operate in accordance with the guidelines provided in this manual.
4.2.10 During installation and maintenance, it is crucial to ensure that all relevant safety equipment is prepared.
4.2.11 Companies that assemble reducers and fans must ensure that they meet the requirements stipulated in this manual.
4.2.12 Labels attached to the gearbox, such as identification plates, directions of rotation, oil levels and other signs that require regular checks, must be kept clean.
4.2.13 All damaged screws, pins and other standard parts must be replaced with others that meet the same technical specifications, such as length and degree of resistance, and must be installed with the same torque.
4.3 Environmental Protection
4.3.1 When carrying out oil changes, use containers designated for used oil. In the event of a leak, immediate cleaning is required.
4.3.2 Anticorrosive agents and used oil must be stored separately.
4.3.3 Proper disposal is mandatory for replaced parts that are corrosive, non-biodegradable or toxic.
4.3.4 If gearbox or fan noise levels exceed local regulations, relevant maintenance must be carried out.
4.3.5 Handling of all pollutants and fan operation must comply with local environmental laws.
4.4 Specific Risks
4.4.1 During related tasks, as the surface of the gearbox is frequently heated, ensure protection against burns.
4.4.2 When changing the oil, due to potentially high oil temperatures, precautions must be taken to avoid burns.
4.4.3 Small contaminants such as dust and sand can enter the gearbox cover and be ejected by the rapidly rotating gearbox. It is essential to provide workers with adequate eye protection.
4.4.4 Ensure that the electrical systems related to the reducer meet the necessary requirements.
5. Transport and storage
Strict adherence to safety regulations during transportation and storage is required.
Gearboxes must be placed on wooden supports or smooth, dry bases during transportation and storage; please do not place them directly on cement floors. Ensure reliable fixation during transportation to avoid collision and shaft rotation.
5.1 Transport
5.1.1 Inspect all parts according to the parts packing list. In case of missing or damaged parts, notify Nan High Gear immediately. This gearbox must not be used for mounting wind turbines.
5.1.2 The type of packaging box is determined by the means of transport. Ensure that the packaging box remains intact during transport and that high-quality transport tools are used.
Rail transport of gearboxes is not permitted. When using ships, choose areas with minimal vibration to protect the engine room and implement relevant safety precautions. Vehicles with excessive vibration should not be used.
5.1.3 The reducer must be transported as a whole unit. If unavoidable, only some components, such as fans, filters and shrink disks, can be packaged and transported separately.
5.1.4 During transport, ensure the safety of motor pumps, fans and hoses. If necessary, they can be dismantled and fixed individually.
5.1.5 Implement waterproof measures to prevent water contamination of the gearbox due to temperature changes.
5.1.6 It is essential to avoid damage to the gearbox caused by rough handling.
5.1.7 The box must not be used for other purposes and the reducer must be fixed inside it.
5.1.8 When lifting the reducer from the box, only use the lifting handles located on the reducer. The angle between the lifting cable and the plumb line must not exceed 30 degrees. See Figure 1 for details.
5.1.9 The movement and storage of the gearbox must maintain the horizontal position or remain the same as its actual working position. Stacking and placing gearboxes on top of each other is not permitted.
5.1.10 The reducer storage location and its packaging must not generate vibrations. During transportation, the gearbox must be placed in a location with minimal vibration or where vibration can be avoided.
5.2 Storage
5.2.1 The reducer must be stored in a dry place, with good air circulation and free from vibrations. Control relative humidity to prevent water vapor from condensing on the surface of parts due to temperature changes.
5.2.2 A protective cover must be installed to prevent dust and other impurities from entering the gearbox.
5.2.3 The reducer must not come into direct contact with water, such as rain or snow, even during brief transport.
5.2.4 The gearbox must be protected with an anti-corrosion agent to prevent corrosion of the output shaft and machined surfaces.
5.2.5 External storage of the gearbox is strictly prohibited. The anti-corrosion period is six months from the date of shipment, provided it is stored indoors. (If the contract specifies other anti-corrosion measures, these must be followed). If the storage period exceeds the permitted anti-corrosion period, a new anti-corrosion treatment must be applied.
5.2.6 When repainting the exterior of the gearbox, care must be taken to protect the non-metallic parts of the gearbox (such as cables) to avoid contact with paint solvents, which can cause rubber aging and affect the performance of the gearbox.
If the storage time exceeds six months, internal protection of the gearbox must be carried out. Turn on the gearbox to remove moisture, dust and other impurities adhering to the gearbox parts, while reforming an oil film on the gear surface, lubricating the bearings and maintaining a good storage environment.
The initialization steps are as follows:
- Make sure the gearbox lubricating oil meets the specified requirements;
- Energize the lubrication system motor pump;
- Turn on the lubrication system motor pump, and then supply the gearbox with a speed of 300 RPM from the end of the high-speed shaft;
- Operate the reducer in this condition for at least 30 minutes;
- Stop the gearbox and motor pump of the lubrication system.
If no oil has been added to the gearbox during this period, first carry out anti-corrosion work, then slowly rotate the gearbox and lubricate the contact points and bearings through the inspection hole cover.
5.2.7 If stored in extremely adverse conditions, such as in a dusty environment or directly outdoors in a wind farm, special protections must be taken to prevent damage to the gearbox. The V-type oil seal and the contact surface of the through cover must be coated with lubricating grease to prevent dust from entering, and anti-corrosion measures must be carried out regularly.
6. Gearbox installation
During the gearbox installation process, strict compliance with safety requirements is essential.
6.1 Unpacking
Experienced and highly qualified professionals must carefully remove the gearbox packaging, including all protective devices used during transportation, and inspect the integrity of all gearbox parts. If any problems arise, notify Nan High Gear immediately.
6.2 Draining oil and removing preservatives
Before installation, residual oil (deposited in the box for preservation) must be drained and anti-rusts from machined surfaces must be removed.
6.3 Installation of high-speed shaft coupling
The gearbox output shaft (high-speed shaft) is connected via a coupling. Accurate alignment during installation is crucial, with the alignment error needing to be kept within the lower limit allowed by the elastic coupling, typically ≤0.05mm, and angular error ≤30″.
(The allowable alignment deviation of elastic coupling is to compensate for deformations caused by load, temperature rise and centrifugal forces during operation, as well as unavoidable manufacturing and alignment deviations, not the allowable installation deviation. The allowable installation deviation must be ≤0.05 mm.
This deviation refers to the value in normal operation. During installation, compensation must be reserved according to the characteristics of the wind turbine.)
Couplings and/or their components must be equipped with suitable installation devices. Shocks and vibrations can damage the high-speed pump and coupling, so they must be avoided; follow the operator's manual. See Figure 2 for “No knocking during assembly” and Figure 3 for “Incorrect examples”.
Special reminder to users: During the gearbox installation process, it is essential not to hit, knock or impose external axial and radial forces on the high-speed shaft, shaft tube or planetary structure without the written consent of our company, as these actions may cause damage to the gearbox.
6.4 Refueling
If the lubrication system is supplied separately, it is crucial to ensure that the system is fully installed and that all pipes are securely connected before refilling. Refueling must be done before testing the engine in the engine room.
Before testing, the lubrication system pump must be turned on, filling the pipes with lubricating oil and coating the gears and bearing surfaces. The cleanliness level of the new oil must be at least -/15/12.
Remove the gearbox inspection port cover for refueling.
6.5 Circuit Connection
Connect the junction box to the control system circuit as required, while ensuring protection of the gearbox circuit system itself. Before performing the engine test, check each circuit to ensure the electrical system is operational.
6.6 Pre-Test Inspection in the Machine Room
The gearbox may be contaminated by foreign objects during refueling (new oil may be dirty) and assembly in the engine room, therefore you must operate the gearbox lubrication filtration system for more than 24 hours before of the test. At this time, the generator speed should not exceed 300 rpm.
Before installing the gearbox in the engine room for test operation, the following items must be inspected:
- Sensors, fan filters, fan motors, oil pump motors, electric heaters;
- All pipeline connections;
- Main shaft connection;
- Brake device connection;
- Electrical system;
All of the above must be confirmed as working.
6.7 Testing the gearbox in the cabin
Under no-load conditions, the maximum test speed (entered into the high-speed shaft) should not exceed 300 rpm. All calibration adjustments must be completed prior to testing, along with adjustment and calibration of all electrical components in the gearbox, and corresponding records must be maintained.
Bolts and other devices external to the gearbox may be reinforced, but no modifications should be made to the gears and bearings inside the gearbox.
6.8 Gearbox Transportation in Random Cabs
The cabin must be stored in a location without sudden changes in temperature, and the humidity inside the cabin must be controlled and maintained below 50% relative humidity. The gearbox must never come into direct contact with water, such as rain or snow. This also applies to short-term storage and transportation.
Storage facilities and transport equipment must be free from vibrations. Cabins equipped with gearboxes must not be transported by train. When using ships, choose a location with minimal vibration to protect the cabin and implement appropriate safety safeguards. Vehicles with excessive vibrations must not be used.
7. Dismantling the gearbox
Strict adherence to safety requirements is essential during the gearbox disassembly process.
7.1 Removing the high-speed coupling
During removal of the high-speed coupler, it is imperative to strictly follow the manufacturer's instructions. However, the following points must be observed to avoid damage to the gearbox interior:
Avoid using a hammer during the disassembly process, as this may cause internal damage to the gearbox.
If support is used during disassembly, the end of the high-speed shaft can be used as a pivot point. Any other points are strictly prohibited.
7.2 Anti-corrosion and Anti-rust Treatment
After completing the removal of the gearbox from the engine room, some machined and connecting surfaces must be protected with anti-corrosion and anti-rust treatments.
The inner and outer surfaces of the hollow shaft (main shaft), elastic support shaft (surface), high-speed shaft extension and brake disc installation surface must be protected with Tectyl 506 or an equivalent anti-rust agent.
8. Startup and Shutdown
Strict compliance with safety requirements is necessary when starting and stopping the gear unit.
8.1 Initialization
Gearbox startup must be in line with the current user manual.
8.1.1 Oil check
Check the oil level using the oil level gauge. The oil level should be checked after the gearbox has been stopped for a period of time and ensure that there is no foam. All pipes must be filled with oil before official departure.
If the display cover needs to be opened, thoroughly clean the dust, sand and other impurities in and around the display cover to prevent foreign objects from falling into the gearbox when the cover is opened. Unscrew the display cover screws and carefully remove the gearbox cover.
When closing the display cover, tighten the screws strictly according to the torque requirements.
8.1.2 Initialization
Before departure, inspections must be carried out in accordance with specifications.
8.1.3 Lubrication System
Before starting the gearbox, make sure that the oil supply system is working properly and that all pipes connected to the gearbox are open except the oil drain port. The lubrication system startup must follow its startup specifications.
8.1.4 Monitoring Items During Startup
The robustness of the lubrication system;
The opening status of the ball valve;
Whether the shaft and gears are rotating normally;
The general seal of the gearbox;
Within 12 days after starting the gearbox, a re-check of the seal and oil level is mandatory.
8.2 Gearbox shutdown
The gearbox shutdown must be in accordance with the current manual.
When the wind turbine is not generating power, the entire drive chain should not be locked on the high-speed shaft of the gearbox or anywhere else. To ensure excellent performance of the gearbox, when the wind turbine is idling, the lubrication system motor pump should not start frequently, but should be maintained at an operating frequency of 5 minutes every 30 minutes.
If there is no power, that is, the motor pump of the lubrication system is not activated, the gearbox can run without load for a month, as long as there is only splash lubrication. However, after a long period of idling, it can only operate normally when the particle size of the gearbox lubricating oil reaches or exceeds -/15/12.
In case of idling, the allowable input (main shaft) speed range of the gearbox is 0-3 rpm.
If the wind turbine drive chain needs to be locked for any reason, the longest period should not exceed one week.
Important Note: If the wind turbine drive chain is locked for a long time, the gear pair will form an interlocking black line due to local wear under the oil-free condition (as shown in Figure 4 below).
The surface of the tooth in the black line already shows damage, impairing the establishment of the lubricating oil film. Corrosion will occur in this area and, under some working conditions, abnormal vibrations and noises may accompany it, drastically reducing the life of the gearbox.
9. Monitoring Requirements
At least the following items need to be monitored:
- Operating temperature: gearbox oil pool temperature, high-speed shaft bearing temperature, etc.;
- Oil Pressure: Gearbox oil inlet pressure;
- Oil level;
- Oil leak;
- Oil Condition;
- Noise and Vibration;
- Input power and maximum load;
- Rotational Speed;
- Gear mesh frequency;
- Rolling Frequency;
Changes in operating temperature and sound vibration may indicate a problem or potential problem, and the cause of such changes must be identified.
Table 1 Summary of control data
| Serial number | Sensor | Data monitoring | Action |
| 1 | Differential pressure sensor for filter | ≥3bar | Replace the filter when the oil pool temperature exceeds 45°C |
| two | Distributor Pressure Sensor | ≤1bar | Alarm, stop after 30 minutes |
| ≤0.8bar | Stop 30 seconds later | ||
| 3 | Oil tank temperature, PT100 | ≤10°C | Activate electric heater |
| ≥20°C | Disable electric heater | ||
| ≥80°C | Alarm, stop after 30 minutes | ||
| ≥85°C | Immediate stop | ||
| 4 | PT100 high speed shaft bearing temperature (motor and rotor side) | ≥90°C | Alarm, stop after 30 minutes |
| ≥95°C | Immediate stop |
9.1 Motorpump control
The process to follow is specific to the gearbox and its necessary conditions. Users must develop their own control strategy based on fan requirements.
9.2 Fan control or water cooling
9.3 Operating Temperature
9.3.1 Ambient Temperature
(Referring to the air temperature near the gearbox inside the machine compartment)
Standard Temperature Type:
- Survival temperature -20°C to 50°C;
- Operating temperature -15°C to 45°C;
Low Temperature Type:
- Survival temperature -40°C to 50°C;
- Operating temperature -30°C to 45°C;
9.3.2 Oil Tank Temperature
The oil tank temperature during normal operation should be below 80°C. If the oil tank temperature exceeds 80°C and remains above this value for more than 30 minutes, the fan must be turned off. If the temperature exceeds 85°C, the fan must be turned off immediately. Before restarting the fan after a high temperature shutdown, an internal inspection must be performed.
9.3.3 Bearing Temperature
Bearing temperature during normal operation should be below 90°C. If the bearing temperature exceeds 90°C and remains above this value for more than 30 minutes, the fan must be turned off.
If the temperature exceeds 95°C, the fan must be turned off immediately. Before restarting the fan after a high temperature shutdown, an internal inspection must be performed.
9.3.4 Lubrication System
When the oil tank temperature is between 0-35°C, the motor pump operates at low speed. When the temperature exceeds 35°C, the motor pump works at high speed.
When the oil tank temperature exceeds 60°C, the fan starts to operate at low speed.
When the oil tank temperature exceeds 65°C, the fan motor operates at high speed. When the temperature drops below 58°C, the fan motor returns to low speed. When the oil tank temperature is below 50°C, the fan motor is turned off.
9.3.5 Extremely Low Temperature
If the reducer begins to operate at extremely low temperatures, a special starting and warm-up procedure approved by the reducer manufacturer must be followed.
Table 2: Low Temperature Startup Process (Necessary Conditions)
| Oil pool temperature | Power | Eletric heater | Oil pump | Generator speed |
| -30℃ -10℃ | 0% | Open | to close | Less than 300 rpm |
| -10°C~5°C | 0% | Open | low speed | Less than 300 rpm |
| 5℃~20℃ | 30% | Open | low speed | |
| 20°C~35°C | 100% | to close | low speed | |
| ≥35℃ | 100% | to close | high speed |
9.4 Oil Level Inspection
Depending on the gearbox, the level indicator may take one or two of the following forms. Users must add oil according to the specific type.
9.5 Oil Sampling
To monitor the normal operation of the gearbox, it is necessary to take oil samples for analysis. Sampling should be done when the gearbox temperature is not too low.
There are dedicated ports for sampling, and special containers must be used for this purpose. Regularly, the oil sample should be submitted for inspection.
After 2,500 hours of operation or every six months, the oil quality should be checked as follows and, if there is a problem, the oil should be changed:
① Check for water and emulsified substances.
② Compare the viscosity with the original. If the difference is greater than 20% or less than 15%, it indicates that the oil has failed.
③ Check for insoluble matter. If it exceeds 0.2%, the oil must be changed or filtered.
④ Perform an emulsion strength test to detect any oil degradation.
⑤ Check whether the additive components have decreased.
A sampling procedure needs to be established. Once the procedure has been defined, all subsequent sampling must be carried out following this procedure.
9.6 Oil Pressure
Under normal operation of the lubrication system, the oil pressure should be between 1-6 bar (at an oil temperature of 65°C) after passing through the filter. If the oil pressure is not within this range, the gearbox should not be used.
Oil pressure can be checked using the hydraulic gauge or pressure sensor on the control and distributor system.
9.7 Internal inspection of the gearbox
The internal components of the gearbox should be inspected at least once a year, and any possible problems will be resolved immediately. Inspection of the inside of the gearbox can be easily carried out through the inspection cover. Access to the parallel stage gears, bearings and internal oil passages can be gained by removing the case inspection cover. Inspection of the planetary stage can be performed through the torque arm inspection cover.
Caution: Make sure nothing enters the gearbox when opening the inspection cover to prevent damage to the gearbox.
The use of an endoscope is recommended for internal inspections.
10. Maintenance and Repair
Strict adherence to safety requirements is essential during gearbox maintenance and repair.
Documenting maintenance and inspection activities is crucial to maintaining a clear understanding of gearbox and spare parts condition, and can guide spare parts inventory management.
10.1 Inspection of flank and crown screws
Gearbox bolts should be regularly checked for pre-tightening condition using the following torque.
Table 3 Screw Torque (Grade 8.8)
| Wire | M10 | M12 | M16 | M20 | M24 | M30 | M36 | M42 |
| Torque, Nm | 39 | 70 | 167 | 350 | 600 | 1150 | 1900 | 3100 |
The preload torque of grade 10.9 bolts should be determined by multiplying the preload torque of grade 8.8 bolts by 1.38 as a standard to inspect the preload status.
10.2 Mandatory Maintenance Items
Table 4: Items requiring maintenance
| Time (in months) after startup. | 36 | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ||
| 30 | ● | ● | ● | ● | ● | ● | ● | ● | ● | ||||||||
| 24 | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ||||
| 18 | ● | ● | ● | ● | ● | ● | ● | ● | ● | ||||||||
| 12 | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ||||
| 6 | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ||||||
| 3-8 weeks | ● | ● | ● | ● | ● | ● | ● | ● | |||||||||
| Test | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ||||||
| Maintain spreadsheet | Oil leak | Oil level | Hydraulic pressure | Filter | Oil volume | Filter replacement | Analysis of oil samples | Oil change | Bearing temperature | Inspect the gears. | Inspect controls and alarms. | Vibration level | Noise level | Visual inspection inside the engine compartment. | Partition surface and gear ring screws | ||
10.3 Common Gearbox Failures
Table 5 Common Fault Analysis
| Defective | Content to check | Measures to take |
| Temperature alarm | 1. Gearbox overload | Reduce the load or change to a higher capacity gearbox. |
| 2. Cooling system | Examine the lubricant flow, cooling system and air filtration system. | |
| 3. Oil level | Check whether the oil level in the tank is too low. | |
| 4. Filter accessibility | Inspect whether the filter is unclogged and whether the filter element needs to be replaced. | |
| 5. Air filter | It must be unobstructed and require regular cleaning with solvent. | |
| 6. Lubricant grade | Follow the instructions in the instruction manual, otherwise an oil change will be necessary. | |
| 7. Oil Seal | Check to see if the labyrinth seal inside the end cap is rubbing against the shaft. | |
| 8. Lubricant quality | Examine the oil for oxidation and ash content; If a problem is found, change the oil and clean the filter. | |
| 9. Oil lubrication system | Make sure that the oil pump is working properly, that the oil flow is smooth, that there is no malfunction in the oil pressure sensing device, and that the oil pump is not sucking in air. | |
| 10. Coupling Alignment | Disassemble the coupling, check the alignment and realign if necessary. | |
| 11. Coupling Axial Distance | Adjust the clearance between devices to reduce axial pressure. | |
| 12. Excessive gearbox speed | Reduce rotational speed or shift to a gearbox that can handle higher speeds. | |
| Vibration noise is loud | 1. Type of coupling used | The coupling can provide a degree of flexibility and allow lateral displacement. |
| 2. Coupling Alignment | If necessary, realign the coupling to minimize imbalance. | |
| 3. If the dynamic balance is excessive | After replacing the coupling on site, dynamic balancing must be carried out again. | |
| 4. Gearbox overload | To reduce the effort, consider replacing the gearbox or lowering the load. | |
| Oil leak | 1. Is the air filter unobstructed? | The air filter must always be clean and unobstructed; if necessary, it must be washed in solution. |
| 2. Are all oil outlets unblocked? | Inspect all oil drain outlets, especially the oil return port from the cover to the housing. | |
| 3. Oil Seal | Check whether the sealing ring on the lid is damaged. | |
| 4. Excessive oil pressure | Check whether the relief valve in the lubrication system is damaged. | |
| 5. Gearbox and end cover | Assess whether the end cap has any dents and whether the screws are damaged. | |
| 6. Oil level | Make sure the gearbox oil level is not too high. |
11 . Lubrication system
11.1 Lubricating Oil
Fill with oil according to the oil mark level.
When leaving the factory, the gearbox is devoid of lubricating oil. This method ensures that no rust forms during an indoor storage period of six months. For long-term storage, specific procedures must be followed, including filling the reducer with lubricating oil. After a stored gearbox has been stored for a long period and is ready for use, the internal components of the gearbox should be inspected before lubricating and cleaning the rust inhibitor.
Oil cleanliness level: Must be at least -/15/12 (ISO4406).
Table 6: Basic Oil Requirements
| Project | Test method | Indicator |
| Density at 15°C | DIN51519 | 860Kg/ m3 |
| Viscosity at 40°C | DIN51562 | 320mm2 /s |
| Viscosity at 100°C | DIN51562 | 37.4 mm 2 /s |
| Viscosity index | ISO2909 NOISE | 166 |
| Flash point | NOISE ISO2592 | 240ºC |
| Pour point | ISO3016 NOISE | -38ºC |
| Federal Law A8.3/90 | DIN51354 | 14+ |
| FVA 54/II, Micropitting Test | 10/High |
11.2 Oil change
Drain the oil from the gearbox through the drain valve;
Empty the oil stored in the filter;
Remove any impurities from the gearbox;
Replace the filter element;
Check the air filter and replace if necessary;
Close all open ball valves;
Start refilling the oil, ensuring that the oil level and granularity meet the requirements.
Oil change should not be delayed for more than 36 months after gearbox operation unless the oil sample has been tested, laboratory tried and found to still be usable.
If the type of lubricating oil has changed, both the gearbox and the lubrication system must be carefully washed with the new oil, followed by complete draining. Use at least 80 liters of new oil for a second wash. If other brands of lubricating oil are used, approval from Nan Gao Gear must first be obtained.
11.3 Replacing the filter element
Check the filter element at least every six months. Filter element replacement should occur within 8 to 12 weeks after gearbox start-up. Afterwards, replacement can be done whenever necessary, but at least once a year.
The steps to replace the filter element are as follows:
11.3.1 Turn off the lubrication system;
11.3.2 Drain the oil;
11.3.3 Unscrew the upper filter cover;
11.3.4 Manually remove the filter cartridge with contaminant-laden holders and replace it, observing any residual contaminants and large particles on the filter surface. Large particles in the filter may indicate a possible problem with the components.
11.3.5 If necessary, clean the filter body, supports and top cover.
11.3.6 Inspect the filter cartridge for mechanical damage.
11.3.7 Examine the sealing rings and replace them if necessary.
11.4 Installing the filter cartridge
11.4.1 Ensure a secure seal between the top cover and the filter cylinder.
11.4.2 Confirm that the new filter cartridge is consistent with the old one.
11.4.3 Carefully install the filter cartridge into the holder.
11.4.4 Carefully mount the support with the new filter cartridge onto the filter support shaft.
11.4.5 Close the lid.
11.4.6 Activate the lubrication system and check if the filter is leaking.
For more details, see the lubrication system fixing manual.
12 . Key points
12.1 Air Filter
Since the air filter contains a dehumidifying or filtering material, its replacement cycle should not exceed 12 months. For details, see the air filter manual.
12.2 Filter Element
The replacement cycle must not exceed 12 months; see section “11.3” for details.
12.3 Lubricating Oil
The replacement cycle should not exceed 36 months, see section “11.2” for more information.
