Summer brings high temperatures, humidity, and frequent rainstorms - all of which can significantly affect the performance and lifespan of Screw Jack units. To ensure safe and efficient operation, the following precautions should be taken seriously.
1. Monitor Operating Temperature
Screw Jack units generate heat during operation due to internal friction between the worm gear and worm wheel. In summer, ambient temperatures often exceed 35°C (95°F), which compounds the heat buildup. Prolonged continuous operation under heavy load can cause overheating, leading to accelerated wear of the worm gear, reduced lubrication effectiveness, and even thermal deformation of components.
Recommendation: Limit continuous running time. Follow the manufacturer's duty cycle rating (typically 20–40% under heavy load). Allow adequate cool-down periods between cycles.
2. Lubrication Management
Heat thins lubricant viscosity, reducing the protective oil film between the worm screw and worm wheel. This increases metal-to-metal contact and wear rate.
Recommendation:
Switch to a higher-viscosity grade lubricant for summer (e.g., high-temperature synthetic grease rated for -40°C to +80°C).
Shorten the lubrication interval - inspect oil condition every 200–300 operating hours instead of the standard 500 hours.
Ensure the grease fitting is accessible and functional; never over-grease, as excess heat can cause seal blowout.
For roller-screw (ball screw) type Screw Jacks, use the specified high-temperature grease - these units offer 92%–98% efficiency but are more sensitive to lubricant degradation.
3. Prevent Moisture and Corrosion
Summer thunderstorms and high humidity create a corrosive environment. Water ingress can contaminate the lubricant, cause rust on the screw shaft, and degrade the housing surface.
Recommendation:
Cover the Screw Jack when not in use, especially outdoors.
After exposure to rain, wipe down the housing and re-apply a light coat of anti-corrosion grease on exposed metal surfaces.
Check that all seal caps and breather plugs are intact.
Install a drain hole in the housing and drain internal condensation regularly to prevent internal corrosion.
4. Check for Thermal Expansion Effects
Metal components expand under heat. In a Screw Jack, thermal expansion of the screw shaft can alter the axial clearance between the worm and worm wheel, affecting positioning accuracy and increasing backlash.
Recommendation:
For precision-positioning applications, allow the unit to reach thermal equilibrium before performing critical adjustments.
Re-verify the zero-point position after extended operation in high heat.
The SWL series typically operates in an ambient range of -20°C to 100°C, but performance degrades near the upper limit.
5. Electrical and Control System Checks
Many Screw Jack systems are driven by electric motors with integrated limit switches and control panels. High ambient temperature can cause:
Motor winding insulation degradation
Overheating of VFDs (Variable Frequency Drives)
False triggering of thermal protection relays
Recommendation:
Ensure motor ventilation fans are clean and unobstructed.
Check that VFDs and control cabinets have adequate cooling or shading.
Monitor motor current - a rise of more than 10% above normal may indicate heat-related inefficiency.
Inspect wiring and cables regularly; high temperatures accelerate insulation aging and can lead to short circuits or fire hazards.
6. Load Rating Derating
Most manufacturers provide a temperature derating curve. At ambient temperatures above 40°C, the allowable load capacity may drop by 10–20%.
Recommendation: Do not exceed the derated load capacity. If the application demands full-rated load in summer, consider upgrading to a larger frame size (e.g., from SWL25 to SWL35) or adding forced-air cooling.
By following these precautions, you can maintain the reliability, accuracy, and service life of your Screw Jack units throughout the hottest months of the year.
