Advantages of hydraulic press:
1. From the structure point of view, the output power per unit weight and output power per unit size of the four types of transmission modes are the most powerful, with a large ratio of moment and inertia. Under the condition of transmitting the same power, the hydraulic transmission device is small in size, light in weight, small in inertia, compact in structure and flexible in layout.
2. From the aspect of working performance, speed, torque and power can be adjusted steplessly, with fast response, fast reversing and speed changing, wide speed range, speed range of 100:1 to 2000:1; good action speed, simple control and adjustment, convenient operation and labor saving, easy to cooperate with electrical control and connect with CPU (computer), which is convenient to realize automation.
3. From the point of use and maintenance, the components have good self lubrication, easy to realize overload protection and pressure maintaining, safe and reliable; the components are easy to realize serialization, standardization and generalization.
4. All the equipment with hydraulic technology is safe and reliable.
5. Economy: the plasticity and variability of hydraulic technology are very strong, which can increase the flexibility of flexible production, and it is easy to change and adjust the production process. The manufacturing cost of hydraulic components is relatively low, and the adaptability is relatively strong.
6. Hydraulic pressure is easy to combine with new technologies such as microcomputer control to form the integration of "mechanical, electrical, hydraulic and optical", which has become the trend of world development and is easy to realize digitization.
Disadvantages of hydraulic press:
Everything is divided into two parts, hydraulic transmission is no exception
1) Because of the relative moving surface of hydraulic transmission, there is inevitably leakage, and the oil is not absolutely incompressible. Coupled with the elastic deformation of oil pipe, the hydraulic transmission can not get strict transmission ratio, so it can not be used in the inline transmission chain of machine tools such as processing thread gears.
2) It is difficult to use hydraulic transmission under high and low temperature conditions.
3) In order to prevent oil leakage and meet some performance requirements, the manufacturing accuracy of hydraulic components is required to be high, which brings certain difficulties to the use and maintenance.
Advantages of air compressor:
1. Using air as the working medium, the working medium is easy to obtain, and the used air is discharged into the atmosphere
2. Because the viscosity of air is very small (about one thousandth of the dynamic viscosity of hydraulic oil), its loss is also very small, so it is convenient for centralized gas supply and long-distance transportation.
3. Working environment adaptability is good, especially in the flammable, explosive, dusty, strong magnetic, radiation, vibration and other harsh working environment, better than hydraulic, electronic, electrical control.
4. Low cost, overload protection.
Disadvantages of air compressor:
1. Due to the compressibility of air, the stability of working speed is slightly poor. However, satisfactory results can be obtained by using gas-liquid linkage device.
2. Because of the low working pressure (generally 0.31.0mpa) and the size of the structure should not be too large, the total output should not be greater than 10-40kn.
3. The noise is big, so muffler should be added when exhausting at high speed.
4. The transmission speed of pneumatic signal in pneumatic device is slower than that of electron and light within the speed of sound. Therefore, pneumatic control system is not suitable for complex circuits with too many components.