Radk Hydro once received a customer complaint: their electro-hydraulic servo valve lost accuracy after long continuous operation. Our engineers investigated the working conditions and offered solutions. What caused this issue?
How high oil temperature hurts proportional servo valve accuracy
Hydraulic oil transfers power in hydraulic systems. Oil performance directly decides system performance. Keeping proper oil temperature is critical for stable operation.
The ideal operating temperature for most hydraulic systems is 40±6°C. This range delivers optimal system performance. High oil temperature brings multiple problems to proportional servo systems.
Problems caused by excessive oil temperature
- Oil viscosity drops as temperature rises. Leakage inside components and the system increases, reducing the volumetric efficiency of hydraulic pumps.
- Lower viscosity changes flow through orifices and valve clearances. Pre-set working speed shifts. It reduces stability and positioning accuracy.
- Thinner oil forms weaker lubrication films between moving parts. Mechanical wear increases. Contaminated oil raises the risk of unexpected failures.
- Heat causes thermal expansion of metal parts. Hydraulic valve components expand and shrink. Clearances between spools and sleeves become smaller. Spool movement gets stuck or wears faster.
- High temperature speeds up oil oxidation. Oil degrades and its service life shortens. Oxidation by-products like asphalt deposits block tiny holes and gaps inside valves. The system fails to work normally.
- Heat accelerates aging of seals. Seals lose sealing ability and lead to oil leakage.
Ways to prevent high oil temperature
- Improve lubrication of moving parts. It cuts friction heat and lowers system load.
- Improve assembly quality and precision of hydraulic components. Control fitting clearances strictly. Use low-friction seal materials and optimized seal designs. Reduce breakaway force of cylinders to minimize friction heat.
- Add cooling units when needed.
Tips
Radk Hydro engineers confirmed the root cause: long runtime heated up hydraulic oil, and this damaged servo valve accuracy. We recommended the customer install cooling equipment to control oil temperature. Ambient temperature rises in summer. Many sites face high working temperatures. Monitor and control oil temperature to maintain stable production.
Radk Hydro is a manufacturer with 20 years of experience in proportional valve and servo valve R&D. Our valves serve industries including steel, power generation, plastic forming, metal forming, material testing and industrial automation. Reach out to us to learn more about our proportional servo valves.
