By Brian Jaworski
Aggregates producers are well advised to keep cone crusher maintenance on the forefront of their operational activities. Here are a few maintenance specifics to consider.
Choke Feeding is a Must
Keeping the cone crusher choke fed during operation maximizes the effectiveness of rock-on-rock crushing, maintains maximum manganese wear life, and ensures a quality product shape. A lack of feed causes inconstant loading of the machine, which affects the long-term life of all internal components.
In the case of an overabundance of fines there is no room for the rock to expand thus leading to high crushing forces and subjecting components to damage and premature wear. Additionally, when not choke-feeding, one is increasing re-circulating loads, which impacts components such as screens or other crushers that are downstream of the circuit. It also results in reduced crusher efficiency and overall throughput.
Make Oil Lubrication Systems a Top Priority
The importance of timely oil changes cannot be stressed enough, as your crusher uses the oil supply for both cooling and lubrication. Allowing the crusher to operate with worn out or contaminated oil could lead to a decrease in bearing and gear life. Check your oil and filters daily and change it at the proper intervals recommended in your owner’s manual.
Always uncover the source of contaminants. For instance, where oil leaks out, contaminants such as dust particles and water can get in. Inspect all your hydraulic systems and tag any leaks for corrective action on the very next maintenance cycle. Completely drain and thoroughly clean out the inside of the oil tank to eliminate any contaminants before refilling.
Use the Correct Oil
The type and condition of your lubrication oil is critical to successful operation of your cone crusher. Crushing with worn out oil or oil of the wrong specification can significantly reduce crusher life. Your crusher is designed to work with the lube oil in the range of 50 F (10 C) to 125 F (51 C).
The maximum oil temperature is controlled by a sensor switch at the reservoir return line. If your crusher is being used regularly in extreme heat (plus 100 F) or cold temperatures (minus 10 F), and it is hard to maintain crusher oil in the correct operating range, it may be helpful to switch to synthetic oil.
Inspect the Main Frame
When changing the outer sleeve bearing, inspect the main frame bore for nicks, burrs, scoring or other damage. Attempt to remove any imperfections with a file or emery cloth. Use a micrometer to measure the bore at the top, bottom and center.
At each position, check the dimension at two places 90 degrees apart. The average of all six measurements must fall within an acceptable range. If high spots cannot be filed down to an acceptable range the bore will need to be re-machined into tolerance.
Check the bore carefully after re-machining for burrs, particularly at the keyways and grooves. A main frame bore that is worn outside the tolerance limits will need to have the worn spots welded up and the complete bore re-machined to tolerance.
Check Your Alarms Daily
If electrical changes are made, or programs are altered in automated systems, verify that all alarms and interlocks still function properly. Don’t be afraid to replace switches or timers that appear damaged or are in poor condition. This is much cheaper than the completion of a major overhaul. Never disable, override or alter any alarms or interlocks!
Get to Know Your Machine and React Accordingly
Record vital machine information such as motor amps, oil temperature and oil pressure in a variety of operating conditions, which will allow you to identify trends and will also help to detect problems before they cause costly damage or downtime.
Brian Jaworski is an engineer with Telsmith.