Greaselubricated Equipment Guideline

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GreaseLubricated Equipment Guideline

1.0Purpose

This document outlines the grease lubricated equipment standards that enable world class lubrication practices.

2.0Scope

This standard covers production and utility equipment in General Mills facilities with grease lubrication.

3.0Uptime Bearing Lubrication

Equipment should be setup so all bearings with a calculated frequency of a month or less can be regreased during uptime. This will ensure the grease is evenly dispersed within the bearing as well as reducing costly downtime for periodic relubrication tasks. It is often the case that bearings are not accessible for regreasing while the machine is in operation, so modifications must be made. The most common solution is to install remote grease lines to bearings from the outside of the machine. This enables safe access to periodically lubricate bearings. The length of the grease line should not cause the grease to exceed its shelf life prior to reaching the component (see next section). This dimension is typically in the range of 4 ft. Single point lubricators should be used in these applications.

4.0Grease Line Length

With all manual or automatic lubrication systems where grease lines are utilized, it is recommended that the length is kept to a minimum. When designing new systems or modifying existing, it is recommended to calculate the grease life based on the usage rate and size of the grease line. To determine the usage rate, use the GMI Bearing Quantity and Frequency Calculator to determine amount and relube interval. Once this is determined, compare this to the volume of the grease line to determine the age of the grease when it reaches the component. Review the following example for explanation.

Grease Life Example

Application – Ball bearings at the top of a 15 ft tall bucket elevator

Bearing – 25.4mm (1”) ID, 52mm OD, 15 mm width, 100 RPM, light abrasive dust

Calculated qty/freq per GMI lube calculator – 3.9 grams every 19 months

Grease line – 15 ft long, 1/8” ID (457.2 cm long, .3175 cm ID)

Grease – Density .881 g/cm3

Volume of grease:

3.9 grams*(cm3/.881g) = 4.42 cm3 per 19 months

Volume of grease line:

πr2h = 3.14*(.3175cm/2)2*457.2 cm= 36.2cm3

Grease age:

(19 months / 4.42 cm3) * 36.2cm3 = 155 months or 13 years old

The grease in this application would be 13 years old by the time it reached the bearing if the grease line was 15 ft long. This would be an ideal application for a single point lubricator versus using a remote zerk with a grease line.

5.0Auto lube Systems

Some equipment applications require the use of automatic lubrication systems. Typically these systems are used on equipment with a large number of lubrication points and are installed to reduce the labor costs associated with proper lubrication. The other instance that typically requires an automatic system is for hard to access lube points.

In order to properly setup an auto lube system for grease applications, the bearing lubrication calculator should be used to determine the proper quantity and frequency. The setup of the auto lube system should match the requirements of each component as determined by the calculator. The equipment OEM can be used to assist with proper design and setup. The final design should be documented and included with the equipment documentation. This information will be required to make any future modifications to the system.

Auto lube systems are not unlike any other asset in our facilities, they must be properly maintained and have appropriate spare parts setup in inventory. Periodic inspection should be done on these systems to ensure they are functioning as designed.