Central lubrication systems

Central lubrication is carried out through systems that allow the lubricant to be continuously supplied to multiple points. Maintaining properly lubricated machinery is an important part of any lubrication program. Without administering lubricant at the proper intervals and in the proper amount, a machine can suffer expensive failures. 

Centralized lubrication systems are a common tool used in industry to distribute precise amounts of grease to specific locations and times using programmable time controllers, grease pumps and grease tips. 

Central lubrication – installations, their structure and advantages

The exact structure of the central lubrication system depends on the type of system chosen. Whether you have a single-line progressive configuration or a two-line parallel configuration can affect the components and their layout, but most systems contain the following basic components:

• central lubrication pumps,
• controllers,
• power lines,
• lubrication tips,
• pressure switches.

Technological advances have created a number of products for controlling and monitoring central lubrication systems that further improve the precision and reliability of these systems. Lubrication tips, supply systems and grease tanks are usually monitored. 

A warning signal is sent when there are abnormal grease flows or when the grease level is low. Incorporating such alarms into the system is useful for preventive maintenance. In addition, to extend maintenance intervals, large-capacity grease reservoirs, which typically hold double the volume of the system’s common reservoir, can be incorporated into systems.

The use of central lubrication systems has many advantages:

• higher reliability of the machine,
• lower lubrication costs,
• economical use of lubricants,
• improved overall machine lubrication,
• reduced grease loss due to controlled wear and tear,
• potentially cleaner plants and machinery.

Jak działają układy centralnego smarowania?

Central lubrication (e.g., Lincoln) is designed to deliver grease or oil to a specific point.In order to inject the right amount of lubricant, the lubricant pump is activated by the controller. This creates pressure in the system, causing the grease to flow out of the lubricant tips. 

In some systems, called direct systems, a pump is used to compress the lubricant and dispense it directly to the application points. Others, called indirect systems, use a pump to deliver the lubricant under pressure, but with dispensing valves at each application point.

The use of a central lubrication system relieves the burden on the machine operator, who does not have to directly control the lubrication process of the machine. A well-chosen system guarantees high accuracy of lubricant dispensing and protects against failure due to seizure of individual parts of the machine. 

Progressive central lubrication system 

Progressive systems provide sequential lubrication of separate lubrication circuits of the machine. When the lubrication pump stops, the pistons of the progressive metering device (progressive distributor for central lubrication) stop in their current position. When the pump starts delivering grease again, the metering device sends grease to the next circuits not yet lubricated. 

Function and features of the progressive central lubrication system

The progressive system is used to dispense oils with viscosities greater than 40 cST and lubricants up to 3 NLGI (National Lubricating Grease Institute). This type of system can be powered by hand, electric and pneumatic pumps. 

The advantages of a progressive central lubrication system include.:

• uninterrupted lubrication – regular delivery of a measured amount of lubricant to each lubrication point,
• reliable monitoring and control – easy system monitoring and simple control, integrated control and monitoring of the system,
• system effective in harsh conditions – also works in dirty, wet or humid environments and at low temperatures.

When to use a progressive central lubrication system?

The progressive system is easy to monitor and control – it distributes the pump’s lubricant flow to separate circuits. The modular concept makes it possible to quickly replace a blocked or damaged component of a particular circuit.

The solution is suitable for small, medium and large machines that require full lubrication control. It is used, among others, in construction machinery (such as: concrete machines, including concrete pump trucks, mortar pumps, loaders, excavators, road vehicles), buses, agricultural machinery, food installations (beverage bottling plants), reciprocating compressors in the gas and oil industry, etc.

How does the progressive central control system work?

In series progressive lubrication systems, a pump is connected to a primary manifold section that distributes grease to secondary manifold sections. The manifold sections contain a series of hydraulically controlled piston valves that deliver the appropriate amount of grease. 

Central lubrication grease is dispensed sequentially by each section, i.e. grease from one section is dispensed after the previous section has finished dispensing grease. If a section dispenses the right amount of grease, it means that the distributor is working properly. However, if a section is defective, the entire manifold is malfunctioning, causing pressure to build up in the circuit feeding the manifold. 

A pressure switch can be installed to monitor the lubrication system by detecting an increase in pressure in the supply circuit. 

Rules of use of the central lubrication system

When planning a lubrication system, the conditions under which the system will be used must first be defined. The number of lubrication points, counter-pressure at lubrication points, operating temperature range, lubricant, feed pump power, control and monitoring, etc. must be correctly defined. 

Why is lubrication important in concrete pumps?

Lubrication is the most important aspect of daily maintenance for concrete pump trucks. Operators should ensure that the boom is lubricated once a week. Most concrete pumps are equipped with systems that automatically lubricate key components.

It is very important to check the amount of grease daily and ensure that it is replenished regularly. Usually, if the automatic lubrication system fails, the operator can manually grease the components using, for example, a hand grease gun.