Cooling
I’ll open this section with a simple and efficient diagram. Inspired from Hagglunds Deck Crane and is about cooling of hydraulic deck crane.
Hydraulic system utilizes a process of energy conversion and transmission. These processes involve losses in which mechanical and hydraulic energy is convert into the heat.
The working temperature is one of the key factors that give the efficiency of hydraulic system. If the temperature is too low the flow resistance is increased, practically the fluid becomes ticker and sluggish and has a negative effect on mechanical output and the pump experienced the suction difficulties. If the temperature is too high leaks in the hydraulic system occur that mean losses and wear are greater.
The size and nature of the heating and cooling system for a hydraulic installation depends on system demands, its precision and life. All these attributes give the type of being used. In majority of cases it is necessary to calculate a heat balance for the hydraulic system. If you need a heat balance study let me know!
Cooling
This deck crane uses a close circuit. Pump takes oil directly from return line. Pump practically is fed back from the actuator. Therefore, return pipe and suction pipe are the same.
As the oil starts to circulate through the hydraulic system internal and external friction causes the temperature to rise and causes leaks in the hydraulic system mean losses and wear are greater. And in time, a result is the incapacity of system to build up required pressure.
A directional control valve is install in the system to direct oil from the return line through the cooler to the tank. The heat return to the tank is partly remove to the outside through the walls of the tank but is too insignificant to provide effective cooling.