Structure Types and Marking Instructions of Screw Jacks

1. Structure Types

• Type 1: In this structure type, the screw rod simultaneously performs a rotational motion and an axial movement. This dual-motion mechanism allows for a more integrated and direct way of converting rotational energy into linear motion. The screw rod, as the main component, undertakes both the task of rotation and the subsequent axial displacement. Por ejemplo, in some small-scale lifting devices where space is limited and a simple yet effective lifting mechanism is required, the Type 1 screw jack can be an ideal choice. Its ability to perform both motions simultaneously simplifies the mechanical design and reduces the number of components needed. Sin embargo, this structure also requires careful consideration of the strength and durability of the screw rod, as it bears both the torque during rotation and the axial force during movement. Any weakness in the screw rod’s material or design can lead to premature failure or reduced performance.
• Type 2: Here, the screw rod performs a rotational motion, while the nut on the screw rod makes an axial movement. This separation of the rotational and axial motion functions provides several advantages. It allows for a more precise control of the axial movement, as the nut can be designed with specific features to ensure smooth and accurate displacement. Además, this structure can be more suitable for applications where a higher load capacity is required, as the load can be more evenly distributed between the screw rod and the nut. Por ejemplo, in industrial machinery that needs to lift heavy objects with high precision, the Type 2 screw jack can offer better performance and stability. The screw rod can be made of high-strength materials to withstand the rotational forces, while the nut can be designed with appropriate threads and lubrication to reduce friction and wear during the axial movement.

2. Assembly Types

• Type A: In this assembly type, the screw rod (or nut) moves upward. This upward movement can be beneficial in many situations, such as when lifting objects from a lower position to a higher one. Por ejemplo, in a production line where components need to be lifted to a specific height for further processing or assembly, the Type A assembly can be easily integrated into the system. The upward movement of the screw rod or nut can be controlled precisely, ensuring that the object is lifted to the correct height without overshooting or undershooting. Además, this assembly type can be designed with safety features, such as limit switches, to prevent the screw rod or nut from moving beyond the intended range.
• Type B: Here, the screw rod (or nut) moves downward. This type is suitable for applications where objects need to be lowered or where the downward movement is more convenient for the overall mechanical design. Por ejemplo, in a material handling system where goods need to be unloaded from a higher platform to a lower one, the Type B assembly can be used effectively. The downward movement can be achieved smoothly by controlling the rotational speed and direction of the screw rod. Similar to the Type A assembly, safety measures can also be implemented to ensure the safe operation of the screw jack during the downward movement, such as braking systems to stop the movement abruptly in case of an emergency.

3. Screw Rod Head Types

• For Type 1 Structure:
  • Type I (Cylindrical): The cylindrical screw rod head is a simple and commonly used design. It provides a smooth and continuous surface, which can be easily connected to other components in the mechanical system. This type of head is suitable for applications where a relatively simple and straightforward connection is required, and where the load is evenly distributed around the circumference of the screw rod. Por ejemplo, in some light-duty lifting mechanisms, the cylindrical head can be used to connect the screw rod to a lifting platform or a drive mechanism.
  • Type II (Flange): The flange-type screw rod head offers a larger connection area, which can provide better stability and load-bearing capacity. It is often used in applications where a stronger connection is needed, such as in heavy-duty machinery or industrial equipment. The flange can be bolted or welded to other components, ensuring a secure and reliable connection. Además, the flange can also be used to mount additional accessories or sensors, such as position sensors or force sensors, to monitor the operation of the screw jack.
  • Type III (Threaded): The threaded screw rod head is designed for applications where a threaded connection is required. It allows for easy attachment and detachment of components, such as nuts or couplings. This type of head is commonly used in systems where the screw rod needs to be adjusted or replaced frequently. Por ejemplo, in a modular mechanical system, the threaded head can be used to connect different modules together, providing flexibility in the system design.
  • Type IV (Flat Head): The flat head screw rod is suitable for applications where a flat surface is needed for connection or where space is limited. It can be used to directly contact other components, providing a simple and compact connection. Por ejemplo, in some precision instruments or small-scale mechanical devices, the flat head can be used to connect the screw rod to a base or a support structure without taking up too much space.
• For Type 2 Structure:
  • Type I (Cylindrical): Similar to the Type 1 structure, the cylindrical screw rod head in the Type 2 structure also provides a smooth and simple connection option. It can be used in applications where a basic and reliable connection is required, and where the load is not too large.
  • Type III (Threaded): The threaded screw rod head in the Type 2 structure is also useful for applications where a threaded connection is necessary. It allows for easy adjustment and connection of components, providing flexibility in the mechanical design.

4. Transmission Ratios

• Normal (P) Transmission Ratio: The normal transmission ratio is suitable for applications where a relatively fast lifting or lowering speed is required. In some production lines or material handling systems where time efficiency is crucial, the normal transmission ratio can help to complete the lifting or lowering operation quickly. Sin embargo, it should be noted that a higher speed may also result in a lower torque output. Therefore, in applications where a large load needs to be lifted, the normal transmission ratio may not be the best choice.
• Slow (M) Transmission Ratio: The slow transmission ratio, on the other hand, is designed for applications where a higher torque output is required. In heavy-duty lifting tasks or applications that require precise control of the lifting or lowering process, the slow transmission ratio can provide the necessary torque to handle the load. Although the speed is lower compared to the normal transmission ratio, the slow transmission ratio can ensure a more stable and accurate operation. Por ejemplo, in the installation of large industrial equipment, where the load is heavy and the precision of the lifting operation is critical, the slow transmission ratio can be used to ensure the safe and accurate placement of the equipment.

5. Protection of the Screw Rod

• For Type 1 Screw Jacks:
  • Basic Type: The basic type of screw rod protection provides the most fundamental level of protection. It mainly focuses on preventing direct physical damage to the screw rod, such as scratches or impacts. This type of protection is suitable for applications where the working environment is relatively clean and there is no significant risk of contamination or corrosion.
  • Anti-Rotation Type (F): The anti-rotation type of protection is designed to prevent the screw rod from rotating unintentionally. This can be crucial in applications where the screw rod needs to maintain a fixed position during operation. Por ejemplo, in some precision positioning systems, the anti-rotation protection can ensure that the screw rod remains stable and does not rotate due to external forces or vibrations.
  • Protective Cover Type (Z): The protective cover type provides a more comprehensive protection for the screw rod. It can prevent not only physical damage but also contamination, such as dust, dirt, and moisture. The protective cover can be made of various materials, such as metal or plastic, depending on the specific requirements of the application. In harsh working environments, such as outdoor or industrial settings, the protective cover type can significantly extend the service life of the screw rod.
• For Type 2 Screw Jacks:
  • Basic Type: Similar to the Type 1 screw jacks, the basic type of protection for Type 2 screw jacks provides basic protection against physical damage.
  • Protective Cover Type (Z): The protective cover type for Type 2 screw jacks also offers enhanced protection against contamination and physical damage. It can effectively protect the screw rod from the harsh working environment, ensuring the reliable operation of the screw jack.