What is a Crusher Hydraulic System?
A crusher hydraulic system is an auxiliary system that uses hydraulic fluid to transmit power and control signals. It is widely used in modern crushing equipment, especially hydraulic cone crushers, hydraulic gyratory crushers, and hydraulic jaw crushers. Its main functions include discharge setting adjustment, overload protection, clearing operations, and equipment lubrication. The hydraulic system makes crusher operation more flexible, maintenance more convenient, and safety higher, serving as a key component for achieving crusher automation and intelligence.
Main Functions of a Crusher Hydraulic System
Discharge Setting Adjustment: Uses hydraulic cylinders to raise/lower the main shaft or rotate the adjustment ring, enabling precise and rapid adjustment of the discharge setting. This can be done during operation or when stopped, with some models supporting online adjustment.
Overload Protection: When uncrushable material (such as tramp iron or bucket teeth) enters the crushing chamber, the hydraulic system instantly releases pressure, allowing the discharge setting to increase and the foreign object to pass through, preventing equipment damage. After the object passes, the system automatically resets and returns to normal operation.
Clearing Operation: When the crusher cannot start due to a stopped-with-load condition or blockage, the hydraulic system can drive the main shaft or adjustment ring in a reciprocating up-and-down motion to discharge accumulated material from the crushing chamber, achieving rapid clearing and significantly reducing downtime.
Locking Function: After the discharge setting is adjusted, hydraulic locking cylinders secure the adjustment ring or main shaft, preventing loosening due to vibration during crushing and ensuring a stable discharge setting.
Automatic Release: During a tramp iron event or overload, the hydraulic system automatically releases pressure to protect the equipment from damage.
Components of a Crusher Hydraulic System
Hydraulic Power Pack: The power source of the hydraulic system, including the hydraulic pump (gear pump, piston pump), motor, tank, level gauge, thermometer, air breather, etc. It provides pressure and flow to the system.
Control Valve Group: Controls the direction, pressure, and flow of the hydraulic fluid. Includes solenoid directional valves, relief valves, check valves, throttle valves, proportional valves, etc., to achieve various actions and functions.
Hydraulic Cylinders: Actuators that convert hydraulic energy into mechanical energy. Includes discharge adjustment cylinders, locking cylinders, clearing cylinders, etc. Depending on the function, there are single-acting and double-acting cylinders.
Accumulator: Stores hydraulic energy, releasing it quickly when needed by the system. Used for absorbing shocks, maintaining pressure and compensating for leaks, providing auxiliary power, etc. Common types are bladder accumulators or piston accumulators.
Piping and Fittings: The channels connecting hydraulic components, including high-pressure hoses, steel pipes, tube fittings, etc., must withstand the system's maximum pressure.
Hydraulic Fluid: The working medium that transmits energy, also providing lubrication, cooling, and rust prevention functions. Appropriate grade anti-wear hydraulic fluid must be selected.
Sensors and Controllers: Monitor system status and issue control commands. Includes pressure sensors, displacement sensors, temperature sensors, PLC controllers, touch screens, etc.
Features of Crusher Hydraulic Systems
Rapid Response: Hydraulic systems react quickly, establishing and releasing pressure instantaneously, effectively protecting the equipment.
Precise Control: Combined with sensors and proportional valves, precise closed-loop control of the discharge setting can be achieved, with accuracy down to the millimeter level.
Convenient Operation: Operations like discharge setting adjustment and chamber clearing can be completed via buttons or a touch screen, significantly reducing labor intensity.
Reliable Overload Protection: The hydraulic system can automatically release pressure during overloads, preventing equipment damage and enhancing safety.
High Integration: Hydraulic components can be integrated into a compact power pack, occupying little space and facilitating installation and maintenance.
Foundation for Automation: The combination of hydraulic and electrical control systems forms the basis for achieving automated and intelligent crusher operation.
Common Crusher Hydraulic System Problems and Solutions
System Fails to Build Pressure or Has No Pressure
Causes: Hydraulic pump damaged or has severe internal leakage; relief valve stuck open or set too low; oil level too low, causing pump cavitation; serious leakage in piping.
Solutions: Check and replace the hydraulic pump; clean or adjust the relief valve; add hydraulic fluid to the specified level; inspect piping and tighten fittings or replace seals.
Hydraulic Oil Temperature Too High
Causes: Cooler blocked or insufficient cooling water; system pressure too high, causing continuous relief; oil level too low; oil viscosity too high or too low; high ambient temperature.
Solutions: Clean the cooler, increase cooling water flow; check if system pressure setting is reasonable; add hydraulic fluid; replace with oil of correct viscosity; improve ventilation and cooling.
Abnormal Noise and Vibration in the System
Causes: Hydraulic pump cavitation (low oil level, suction line leak); severely worn pump; relief valve spool dithering; piping not securely fixed; air in the hydraulic fluid.
Solutions: Add hydraulic fluid, check suction line seals; inspect and replace the pump; clean the relief valve, check the spring; secure piping; bleed air from the system.
Hydraulic Cylinder Moves Slowly or Not at All
Causes: Low system pressure; insufficient flow; directional valve stuck or solenoid failure; severe internal leakage in the cylinder (piston seal damaged); excessive load.
Solutions: Check system pressure and flow; clean or replace the directional valve; check the solenoid coil; inspect and replace cylinder seals; check the load condition.
Hydraulic Fluid Contaminated or Degraded
Causes: Entry of external dust and moisture; hydraulic fluid used for a long time without replacement; high oil temperature accelerating oxidation.
Solutions: Regularly replace hydraulic fluid and filter elements; check tank seal and air breather; control oil temperature within the normal range; regularly sample and test oil quality.
Piping Leaks
Causes: Loose fittings; O-rings aged or damaged; hoses aged or cracked; excessive piping vibration.
Solutions: Tighten fittings; replace O-rings or seals; replace hoses; add pipe clamps for vibration damping.
What is a Crusher Lubrication System?
A crusher lubrication system is an auxiliary system that supplies lubricating oil to various moving friction pairs of the equipment (such as bearings, gears, eccentric bushings, etc.). It is widely used in various types of crushing equipment. Its main function is to form an oil film on friction surfaces, reducing wear, lowering frictional resistance, carrying away heat, flushing away wear debris, and preventing rust, thereby ensuring long-term, stable, and reliable operation of the crusher. The lubrication system is the "blood circulation system" of the crusher; its working condition directly affects equipment life and operational efficiency.
Main Types of Crusher Lubrication Systems
Oil Lubrication System: Uses mineral oil or synthetic oil as the lubricating medium. A pump delivers the lubricating oil to various lubrication points, and the oil returns to the tank after lubrication, where it is filtered and cooled before being recirculated. Suitable for heavy-duty parts like main bearings, transmission bearings, and gears in medium and large crushers.
Forced Circulation Lubrication: Oil is forcibly supplied by a pump, providing ample oil flow and good heat dissipation, suitable for high-speed, heavy-duty equipment.
Spray Lubrication: Uses compressed air to atomize lubricating oil and spray it onto lubrication points, suitable for high-speed gears and bearings.
Grease Lubrication System: Uses grease as the lubricating medium. A manual or automatic lubrication pump delivers grease to various lubrication points at timed, measured intervals. Suitable for low-speed, intermittent motion, or areas with high sealing requirements, such as vibrating screen bearings and small crusher bearings.
Manual Grease Lubrication: Operators periodically inject grease using a grease gun or manual lubrication pump.
Automatic Grease Lubrication: Composed of an electric lubrication pump, distributors, and a controller, achieving timed, measured automatic grease injection.
Components of a Crusher Oil Lubrication System
Tank: Stores lubricating oil, typically equipped with accessories like a level gauge, thermometer, heater (for cold regions), and air breather.
Oil Pump: Provides power for the lubricating oil, commonly gear pumps, screw pumps, etc. Often configured as one working and one standby, or dual pumps, to ensure oil supply reliability.
Cooler: Cools the returning oil, controlling the oil temperature within the normal range. Commonly air coolers or water coolers are used.
Filter: Filters impurities from the lubricating oil, ensuring oil cleanliness. Includes suction filters, return line filters, high-pressure filters, etc., often equipped with a clogging indicator.
Valve Group: Controls the direction, pressure, and flow of the oil circuit. Includes check valves, relief valves, throttle valves, directional valves, etc.
Piping: Channels connecting components, including main lines and branch lines, requiring reasonable layout to avoid excessive bends.
Distributors: Evenly distribute lubricating oil to multiple lubrication points.
Sensors and Instruments: Monitor system status, including pressure gauges, pressure switches, temperature switches, flow switches, level switches, etc.
Control Panel: Controls pump start/stop, monitors system status, issues alarm signals, and can be interlocked with the crusher's main control system.
Features of Crusher Lubrication Systems
Reduces Wear: Forms an oil film on friction surfaces, separating the relatively moving metal surfaces and significantly reducing wear.
Lowers Temperature: Circulating lubricating oil carries away heat generated by friction, preventing equipment overheating.
Flushes and Cleans: Flowing oil can flush away wear debris and impurities from friction pair surfaces, keeping them clean.
Prevents Rust: The oil film covers metal surfaces, isolating them from air and moisture, preventing rust.
Sealing Effect: Grease can provide an auxiliary sealing function in areas like bearing housings, helping to prevent external dust ingress.
Extends Life: Good lubrication can significantly extend the service life of equipment components and reduce maintenance costs.
Automatic Monitoring: Modern lubrication systems are equipped with various sensors for real-time monitoring of parameters like oil level, temperature, pressure, and flow, enabling automatic alarms and interlock protection.
Common Crusher Lubrication System Problems and Solutions
Oil Pump Delivers No Oil or Insufficient Flow
Causes: Tank oil level too low; suction line blocked or leaking air; incorrect pump rotation direction; severely worn pump; filter clogged.
Solutions: Add lubricating oil to the specified level; clean the suction line, check seals; correct motor rotation; inspect and replace the pump; clean or replace the filter element.
Oil Temperature Too High
Causes: Cooler blocked or has insufficient cooling capacity; system pressure too high, causing excessive relief; oil level too low; oil viscosity too high or oil degraded; abnormal wear and heating of bearings or gears.
Solutions: Clean the cooler, check cooling water or fan; check system pressure setting; add lubricating oil; replace with oil of correct viscosity or new oil; check equipment operating status.
Abnormal System Pressure (Too High or Too Low)
Causes (Too High): Relief valve malfunction or set too high, pipeline blockage.
Causes (Too Low): Pump failure, relief valve stuck open, severe pipeline leakage.
Solutions: Check and adjust the relief valve; check the oil pump; check pipeline seals; clean or replace valve components.
Oil Contaminated or Degraded
Causes: Entry of external dust and moisture; filter element clogged and not replaced in time; high oil temperature accelerating oxidation; mixing of different brands of oil.
Solutions: Regularly replace lubricating oil and filter elements; check tank seal; control oil temperature; avoid mixing different oils; regularly sample and test oil quality.
Pipeline Leaks
Causes: Loose fittings; seals aged or damaged; hoses ruptured; excessive pipeline vibration.
Solutions: Tighten fittings; replace seals or hoses; add pipe clamps for vibration damping.
Poor Oil Return or Bubbling in Tank
Causes: Return line blocked or diameter too small; tank vent blocked; oil level too high; return line not submerged below oil level, entraining air.
Solutions: Clean the return line; clean the vent; adjust oil level to the appropriate range; ensure the return line is submerged below the oil level.
