To avoid the negative impact of temperature changes on the sealing performance of the ZQD400-80-1 gear reducer, measures need to be formulated around the four core dimensions of seal Selection adaptation, structural optimization, temperature control, and maintenance specifications to form a full-cycle protection system, as follows:
1. Seals that accurately adapt to temperature characteristics
Priority is given to sealing materials that are resistant to high and low temperatures: the oil seal lip is made of fluororubber (FKM) or hydrogenated nitrile rubber (HNBR), which can withstand a wide temperature range of -20°C to 150°C to avoid low-temperature hardening and high-temperature aging; the sealing pad is made of flexible graphite composite pad or metal-coated pad to replace ordinary rubber pads to improve temperature resistance and sealing stability.
Match the sealing structure corresponding to the temperature: under high-temperature working conditions, a double-lip oil seal with a dust lip + spring preload is used to enhance lip fit; under low-temperature working conditions, a lip-coated oil seal with a low friction coefficient is used to reduce friction damage during startup.
2. Optimize structural design to offset the effects of thermal expansion and contraction.
Install a compensation structure: Use an elastic sealing gasket + anti-loosening bolt combination at the flange connection. The bolts are made of material with a thermal expansion coefficient close to that of the box. At the same time, a disc spring washer is installed to offset the bolt loosening caused by temperature fluctuations and ensure a stable sealing force.
Design a pressure balance device: Install a breathing valve or vent cap on the top of the reducer box to promptly discharge the internal pressure generated by the expansion of oil at high temperatures to prevent excessive internal pressure from opening the sealing surface; use a vent cap with heating function in low temperature environments to prevent the vents from being blocked.
Optimize the matching accuracy of the shaft and oil seal: the surface roughness of the sealing section of the shaft is controlled at Ra0.8~1.6μm, and the hardness reaches above HRC55, which reduces the wear of the shaft and the oil seal lip when temperature changes; if necessary, install a sleeve on the shaft end to facilitate subsequent replacement and maintenance.
3. Actively control temperature to reduce temperature fluctuations
High temperature protection: When the operating oil temperature exceeds 90°C, install an air-cooled radiator or water-cooled heat exchanger to control the oil temperature within the optimal range of 60°C to 80°C; regularly clean the dust on the heat sink fins of the box to improve natural heat dissipation efficiency; avoid long-term overload operation of the reducer and reduce heat generation from the source.
Low temperature protection: When the ambient temperature is below - 10°C, preheat the reducer before starting. The lubricating oil can be heated by an external heating belt or a thermal medium. Wait until the oil temperature rises above 10°C before starting the equipment. If the ambient temperature is extremely low after shutdown, the lubricating oil can be drained or a gear oil with good low-temperature fluidity (such as L-CKD 220) can be used.
Reduce temperature difference impact: Avoid frequent starting and stopping of the reducer in high and low temperature environments. After starting, run without load for 10 to 15 minutes, and then load after the temperature stabilizes to reduce the temperature difference stress between components.
4. Standardize maintenance and extend the life of the sealing system
Regularly check the sealing status: every 1,000 hours of operation, stop the machine to check whether the oil seal lip is aged, whether the gasket is deformed, whether the bolts are loose, and if any leakage is found, deal with it promptly; every 3,000 hours or 6 months, preventively replace the oil seal and gasket.
Optimize lubricant management: Use extreme pressure gear oil with a wide temperature range (such as L-CKD 320, applicable temperature - 15°C ~ 120°C) to ensure that the oil cleanliness reaches NAS level 8 or below; regularly monitor the oil viscosity and moisture content to prevent oil deterioration from aggravating seal damage.
Protect the environment: The reducer installed outdoors should be equipped with an insulation cover or awning to avoid direct sunlight, rain and snow, and reduce the impact of ambient temperature on the equipment itself.
