Identifying and fixing grease and oil leakage in Screw Jacks

1. Introduction

Lubricants such as greases and oils are essential for the service life of Screw Jacks and gear drives. They reduce friction, protect components from wear and corrosion, and help dissipate heat. Nevertheless, depending on the application and environment, lubricant leakage can occur. This article highlights typical causes and shows how these issues can be prevented or remedied.

2. Importance of lubricants

Greases and oils serve multiple functions in Screw Jacks:

1. Reduce friction and wear on sliding components
2. Protect sensitive surfaces from corrosion
3. Transfer heat away from the interior of the gearbox
4. Provide capillary action to reach hard-to-access areas

Unintended lubricant loss can not only cause contamination but may also lead to premature system failure.

3. Causes of grease and oil leakage

3.1 Bleeding of lubricants

“Bleeding” occurs when the liquid and solid components of a grease separate. This typically happens during long-term storage without movement, such as when spare gearboxes remain unused for months or years.

3.2 Overfilling the gearbox

Screw Jacks are delivered with a specific amount of grease. Overfilling the gearbox afterward can cause excess grease to escape during operation or heating – for example, through seals or vent openings.

3.3 Damaged seals

Seals on the lifting element can be damaged during transport or incorrect assembly. Once damaged, they can no longer reliably contain the lubricant, especially under temperature changes or pressure variations.

3.4 Overhead installation (Lead screw on top)

When a standard Screw Jack is installed overhead, grease can move toward the screw and escape more easily. Gravity can exacerbate this, leading to unwanted “excess grease” at the screw.

4. Measures to prevent or correct leakage

4.1 Counteract bleeding: Activate the lubricant

Simply mixing the grease at startup is often enough to re-incorporate separated oil. Alternatively, a grease change before commissioning can be performed.

4.2 Check grease quantity

The gearbox should never be filled beyond the recommended level. When in doubt, consult the manufacturer.

4.3 Replace seals

Damaged seals can often be replaced easily. If the damage occurred during manufacturing or transport, it may be covered under warranty.

4.4 Special option: Dual-chamber lubrication

To prevent grease migration entirely, some Screw Jacks can be ordered with dual-chamber lubrication. The gearbox is hermetically sealed so grease cannot rise to the lead screw. Note: In this configuration, the lead screw must be lubricated manually.

5. Conclusion

Grease and oil leakage is usually not a sign of defect but results from typical operational errors or external influences. With basic technical understanding and adherence to key rules, such as protecting seals, correct installation orientation, and proper gearbox filling, many problems can be prevented in advance. For special installation scenarios like overhead mounting, proven special solutions are also available.

6. Conclusion

Squeaking noises in linear drive systems are not merely a nuisance, they are almost always an indication that something is wrong within the system. Common causes such as insufficient lubrication, impermissible mechanical stress, or lateral forces can usually be identified with experience and corrected quickly. Early intervention not only prevents consequential damage and unplanned downtime, but also ensures long-term reliable and quiet operation.