Crankless Press Guide

The crankless press is a press designed for the pressure processing industry and sheet metal forming. The crankless press, also known as the eccentric press, is an excellent machine with high quality, high efficiency, maximum safety, and easy-to-operate mechanical characteristics. It has a high-precision machine structure, including the crown and base frame. The welded steel is formed by annealing to eliminate the residual stress. The crankless press is one of the most widely used press systems. It is convincing with its fast cycle time and variable lifting power. It is mainly used for press applications that only require short strokes. The crankless press has an electromechanical drive: an electric motor drives a flywheel, which is connected to the coupling eccentric device. Just press a button, the eccentric device will grab and trigger the stroke. In addition to the crankless press, the blanking machine with eccentric technology has established itself in the same way.

How does a crankless press work?

To drive an eccentric shaft, which rotates in a connecting rod, a crankless press uses an electric motor. In the slider joint, the connecting rod pushes the hammer single-dimensionally. The eccentric shaft itself is spherical, but inside the connecting rod it can rotate entirely. The middle of the drive is not the entire shaft's center. The center of the drive remains constant as the engine rotates, but the general center of the shaft varies. This allows the axis, offering movement, to shift location. The crankless press therefore operates through a so-called eccentric mechanism which needs to turn circular motion into linear motion. In other words, the impact force comes from the electric motor in an eccentric press, which circulates and thereby produces the power to strike the metal with the hammer.

Structure and Advantages of a Crankless Press

The box-type slider of the crankless press is designed as an eight-way cantilever guide rail and is driven in a vertical motion. It can maintain pressure accuracy during long-term operation and provide stable and equal pressure capacity. Modern crankless presses have a safe drive mechanism in long-life brakes, and the clutch adopts a well-designed single joint structure. The crank press has the advantages of accurate movement, high sensitivity, easy adjustment, and maintenance, and can realize a high-efficiency and long-life operating system equipped with a fully electronic control integrated system.

This not only ensures the accuracy of the movement, but also is easy to maintain, and is scalable, and can be integrated with the forming mechanism and the beating system. The continuity and smooth operation of the crank press are ensured by an independent built-in operation panel, which is also easy to use with complete equipment and safety protection devices. Other advantages of a crankless press include long stroke, high output rate, short contact time, long non-contact time during mold cooling, long mold life, large mold space, small final tolerances, and high part quality.

D-Shape vs. C-Shape Crankless Press

The steel welded frame of the D-shape crank press has a structural design that resembles the letter D, which has a significant advantage even when the maximum press capacity is used, that is, the angular deflection is almost eliminated. This leads to very precise performance, which is widely used in electronics, telecommunications, computers, household appliances, furniture used, and so on.

The frame of the C-frame crankless press is made of steel plate. Although these frames can better access the mold setting area from the front and sides of the press, the important factors of C-Gap must be carefully considered. To protect the C-shaped gap from distortion, in addition to designing the body based on engineering principles and benefiting from modern analysis software, the necessary parts on the frame have also been strengthened, so that the frame structure is placed within international safety standards.

For the crankless presses of D-frame and C-frame, the stress relief process is carried out after welding. Then, the fixed and moving parts and the basic surface of the shaft will be carefully processed by a boring machine. Due to the accuracy of the above process, the precise parallelism of the punch and the plate and the vertical angle of the punch to the backing plate can be maintained for many years. Therefore, in addition to high-quality production, the durability of the press and mold will also be improved.

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