This is a set of suitably interconnected elements providing periodic lubrication to the different moving parts of a machine or plant. This set usually consists of: pump, distributors, dosing valves, fittings, pipes, programmer and control accessories. Centralised lubrication normally operates on non-reused oil.
LOW PRESSURE LUBRICATION
Lubrication is defined as low pressure when an operating pressure of 2-3 bar is sufficient to allow oil to reach the muving surfaces.
It is suitable for lubricating small and medium sized machines and is obtained with simple, compact, economic system.
Low Pressure lubrication is particularly recommended for high precision machine tools (such as grinding and boring machines, lathes, etc.) in which lubrication must not alter the stability of the machine’s slides and screws.
The moving parts must be suitably prepared.
The AZETA line includes manual and electric-cyclic volumetric pumps as well as vibration pumps. It is necessary to use resistive dosing valves as well as new and clean oil.
MEDIUM PRESSURE LUBRICATION
Lubrication is defined as medium pressure when an operating pressure of 20-40 bar is used.
It is suitable for large machines with many lubrication point, which may be a long way from each other.
Medium pressure eliminates foreign matters and coolants from lubrificated parts.
Medium pressure entails using volumetric dosing valves operating ad a set, constant volume of oil or fluid grease.
The AZETA line includes volumetric pneumatic pumps and gear pumps.
AZETA AIR MIST LUBRICATION
A minimal lubrication system operating on ultra low oil consumption.
Compresses air is used as a carrier.
Metered oil, suitably mixed with air, is conveyed in non atomised state to the lubrication point.
AZETA AIR MIST is especially recommended for lubrication of high speed rolling contact bearings on spindles, electro-spindles and of rotating bushes of lathes with sliding headstock.
For linear guides, the continuous flow keeps clean the tracks and races of balls or slides, as well as the contact races of rolling contact bearings.
Whenever this type of pump is activated, a pre-set volume of lubricant is supplied.
CONTINUOUS DUTY PUMP
When operating, this pump delivers a pre-set quantity of lubricant per time unit.
A manually activated volumetric pump.
The required volume is delivered by a plunger piston thrust by suitably pre-loaded mechanical spring of adequate size. Oil volume can be adjusted.
An electrically activated volumetric pump with pre-set pause times.
The required volume is delivered by a plunger piston thrust by a suitably pre-loaded mechanical spring of adequate size.
Oil volume can be adjusted.
A low pressure continuous duty volumetric pump with relative flow rate in excess of the total flow rate of the dosing valves. Excess oil flows through a maximum level valve and returns to the tank.
This process continues until the pump is turned off, thus maintaining lubricant in the dosing valves ad constant pressure.
Lubricant volume is determined by operating time.
A medium pressure volumetric pump activated by compressed air and with a (theoretically) pre-set air-to-oil ratio. The AZETA range includes this pump with a plunger piston for low volumes and another type with piston plus lip seals for high volumes.
The lubricant volume per lubrication point is determinated by the (volumetric) dosing valves.
The total flow rate of the dosing valves can be, at maximum, 2/3 of pump flow rate.
LUBRICATION CONTROL UNIT
Known as a control unit, as it is similar to low pressure hydraulic control units used for lubrication. It consists of an electric motor, a gear pump and a valve set. The control unit feeds and keeps the lubricant at constant pressure within a lubricating network, which may be wide ranging and without any limit to its relative flow rate.
The lubricant volume per lubrication point is determined by the (volumetric) dosing valves.
An element which injects and meters the lubricant.
– resistive dosing valve: for metering a pre-set quantity of oil drops per minute
– volumetric dosing valve: for metering a pre-set volume of oil per stroke (irrespective of oil temperature and viscosity).
The volume of oil delivered by the pump per time unit or per activation.
RELATIVE FLOW RATE
This is an important criterion for selecting both pump and dosing valves.
In the case of resistive dosing valves, it corresponds to the number of oil drops delivered per minute. As far as pumps are concerned, this data-item is used to determine oil volume delivery time.
In the AZETA system, when the total of the relative flow rates of the dosing valves is equal to the relative flow rate in the pump, the entire volume of the pump is delivered in three minutes.
The greater the sum of the relative flow rates of the dosing valves, the shorter the pump delivery time.
The data refer to oil with viscosity of 65 cSt at 40°C, and to tests run at a temperature of 20°C.
Flow resistance of a liquid (oil) caused by friction between its molecules.
In this web site, this value is always expressed in centiStokes (cSt) at a reference temperature of 40°C.