Key Points and Difficulties in the Lubrication of Screw Pump Machine Tools

As a core lubrication component of machine tools, the lubrication effect of screw pumps directly determines the machining accuracy and service life of machine tools. Machine tool guideways are a lubrication difficulty—guideways move reciprocally with large changes in speed and load, which are prone to crawling and may even lead to machine tool scrapping in severe cases. To address this challenge, selecting a reliable lubrication system is particularly crucial. Omron Tech Pumps, deeply engaged in the industrial chemical field, is committed to providing high-performance screw pumps. Combining practical experience and technical key points, this article sorts out the core requirements, difficulties and coping ideas of screw pump lubrication, providing a reference for operation and maintenance work and helping to achieve more efficient and stable lubrication management.

I. Core Difficulty: Guideway Crawling and Dynamic Stability of Screw Pumps

Guideway lubrication is the weakest link in the system. Due to the reciprocal movement of guideways and huge load fluctuations, it is difficult to form a stable hydrodynamic oil film between friction pairs.

Analysis of Crawling Phenomenon:

When the anti-crawling performance of lubricating oil is insufficient or the pressure pulsation of the screw pump is too large, the guideway will produce intermittent sliding, namely crawling. This not only reduces machining accuracy but also may lead to machine tool scrapping in severe cases.

Scientific Research Countermeasures:

While developing lubricating oils with high anti-crawling performance, screw pumps must be required to have extremely low flow pulsation. Optimizing the screw profile design to provide stable forced circulation pressure is the key technology to eliminate crawling from the power source.

II. Nine Key Requirements for Machine Tool Lubrication Systems

Combined with industry experience and equipment operation data, the lubrication system driven by screw pumps must meet the following core requirements:

1.Multi-point complex lubrication → Must be automated

Machine tools have many lubrication points with wide distribution. Manual oiling is inefficient and unreliable. The automatic lubrication system composed of screw pumps + distributors + PLC control can realize timed, quantitative and on-demand oil supply.

Hydraulic and lubrication systems are often shared → Oil products need to meet dual performance

Many machine tools combine hydraulic stations and lubrication stations to simplify the structure. At this time, the lubricating oil must meet both:

Anti-wear and anti-rust requirements of the hydraulic system;
High oil film strength and oxidation resistance of lubrication points.

✅ Recommendation: High-performance anti-wear hydraulic and guideway oil (such as ISO VG 68).

3.Gravity lubrication is partially adopted for large machine tools → Need to match oil fluidity

For parts such as main bearings, drip oil or wick lubrication may still be used. At this time, the lubricating oil should have a low pour point and good fluidity to ensure that it can flow to the friction pairs by itself in low-temperature environments.

4.Large power loss in the transmission system → Prefer low-friction lubricating oil

Equipment such as universal grinders has complex transmission, and friction loss can reach 30–40%. Selecting lubricating oil with low viscosity but high extreme pressure performance can significantly save energy and reduce consumption.

5.Impact load generated in rough machining → Enhance extreme pressure and anti-wear performance

Intermittent cutting brings impact load, and lubrication is prone to enter the boundary state. The lubricating oil needs to contain effective EP/AW additives (such as sulfur-phosphorus type) to prevent micro-pitting and scratching.

6.Strict control of temperature rise for precision machine tools → Accurate calculation of oil volume and cooling

The increase in oil temperature will change the viscosity and affect the oil film thickness. Precision machine tools require the oil temperature to not exceed the room temperature by 2–5℃. It is necessary to reasonably design the oil tank volume and heat dissipation area, and consider installing an oil cooler.

7.Seal failure → Contamination is an "invisible killer" of the lubrication system

If metal chips and grinding powder enter the lubrication system through the seal gaps, they will:

Block the screw pump clearance;
Scratch the guideway surface;
Accelerate the oxidation and deterioration of oil products.

✅ It is necessary to strengthen the sealing grade of shaft seals, pipe joints and breathers.

8.Coolant mixing → Oil products require strong anti-emulsibility

Emulsions or sodium tripolyphosphate solutions may penetrate into the oil circuit, leading to emulsification of lubricating oil, increase in acid value and failure of anti-rust performance. Therefore, it is necessary to select oil products with high anti-emulsibility and good water separation performance.

9.Prevention and control of guideway crawling → Lubricating oil needs to have "anti-crawling performance"

This is the key to the success of guideway lubrication. In addition to viscosity matching, special guideway oil containing adhesion enhancers and friction modifiers should be preferred to ensure the formation of a stable oil film at low speeds.

III. Summary

The lubrication of screw pump machine tools should be based on core requirements, focus on the key points of guideway lubrication, and solve difficulties such as crawling, impurities and temperature rise. With professional screw pump products and lubrication solutions, Omron Tech Pumps helps enterprises achieve two-way coordination between pumps and machine tools through parameter optimization, system protection and regular operation and maintenance, thereby effectively extending equipment life, ensuring machining accuracy, reducing operation and maintenance costs, and meeting the requirements of high-stability industrial production.

For more information on products suitable for your production line, please visit www.Omron Tech Pumps.com