It is mainly divided into four column oil press (three beam four column, five beam four column), double column oil press, single column oil press (C-shaped structure), frame oil press, etc.  
Classification according to the purpose of oil press  
It is mainly divided into metal forming hydraulic press, bending hydraulic press, stretching hydraulic press, blanking hydraulic press, powder (metal, non-metal) forming hydraulic press, press fitting hydraulic press, extrusion hydraulic press, extrusion molding, etc.  
The oil press directly driven by the oil press pump has the following characteristics  
1. The stroke speed of the movable beam of the hydraulic press depends on the liquid supply of the pump, but has nothing to do with the deformation resistance of the forging in the process. If the liquid supply of the pump is constant, the working speed of the oil compressor is a fixed value.  
2. The liquid supply pressure and power consumed by the pump are related to the deformation resistance of the processed workpiece. When the working deformation resistance is large, the liquid supply pressure and power consumed by the pump are also large, otherwise it is small.  
3. The characteristics of constant travel speed of the movable beam and the change of pump liquid supply pressure can be used as the signal to operate the distributor to realize the automatic control of the oil press.  
4. The basic investment is low, the floor area is small, and the daily maintenance is simple. The hydraulic pumps in the pump direct transmission system are selected according to the maximum working speed and working pressure of the hydraulic press. However, the hydraulic pumps are not fully utilized when the hydraulic press is in small filling stroke, return stroke, auxiliary process and required working pressure, especially the large tonnage hydraulic press, whose utilization coefficient is very low. Therefore, the hydraulic press tends to drive the working speed and working pressure step by step.