Merits of Hydraulic system
1) We can generate very high pressures in hydraulic system. Due to this nature of hydraulic system we can use this power to lift, hold, press very heavy loads. 2) Weight to power ratio of a hydraulic system is comparatively less than that of an Electro-Mechanical System. Electric motor weigh appropriately 8.5 Kg/kW whereas, same power hydraulic motor weighs 0.85 kg/kW only. 3) The speed control of linear as well as rotary actuators can be achieved with ease. By merely adjusting small flow control valve, wide range of speed and feed can be obtained. 4) Limiting and balancing of hydraulic forces can be easily performed.
Demerits of hydraulic system
1) Elements of hydraulic system have to be machined to high degree of precision which increases manufacturing cost of system. 2) The hydraulic system, due to oil leakages is ‘dirty’ and we cannot use this system in food and pharmaceutical industry. 3) Petroleum based hydraulic oils can create fire hazards if the temperature of the system goes beyond its ‘flash point’ 4) Leakage of hydraulic oil during its flow in system causes heavy pressure drops