How to choose the ideal electromechanical lifting element

Here are the key categories to consider when selecting a lifting element:

1. Load Requirements

Consider the weight or load that the lifting element needs to move. This affects the required load capacity of the component. For all available drives, you can find the maximum load capacity in our catalogs. In summary, the lifting elements can handle the following loads:

The illustrated loads define the purely static load capacity of the basic bodies. Depending on speed or lift height, the performance level and buckling must also be considered.

2. Stroke length

Determine the maximum stroke length the lifting system needs to cover. This impacts the length of the spindle or chain and thus the design of the drive. For tension-loaded spindles or chains, the maximum achievable stroke length is primarily limited by manufacturing technology or raw material availability (e.g., single-piece spindles can be manufactured up to 6 meters as the standard length of raw material does not exceed 6 meters. Moreover, logistics and assembly become significantly more complex with longer spindles).

Planning Advice for Linear Chain: The chain itself consists of individual, interconnected links. Thus, there is no limitation due to raw material. If the chain is continuously guided, there is no limit to the stroke length (apart from the chain's own weight).

Compression-loaded spindles must always be checked for buckling. All spindles and chains used are designed for the defined loads of the lifting elements. However, with long compression-loaded components, a stability issue arises.

3. Speed requirements

Determine the speed at which the load needs to be moved. This affects the choice of the appropriate gear ratio and motor speed. Additionally, it must be confirmed whether the chosen lifting element can achieve the desired speed. The permissible speed is directly related to the power absorption capability of the lifting element. Efficiency and load influence the required power of the lifting element.

4. Accuracy requirements

When precise positioning is necessary, consider the accuracy requirements. This might involve choosing a specific type of spindle or integrating feedback devices such as encoders. The direction of the load is also essential. If the lifting elements are subjected to load in only one direction (either only tension or only compression), the consideration of reversing play can be omitted.

5. Environmental conditions

Consider the environmental conditions in which the actuators will operate. Factors such as temperature, humidity, dust, or aggressive chemicals can influence the choice of materials and protection methods. Many lifting elements can be additionally protected by options such as bellows, protective tubes, piston rods, spiral springs, etc.

6. Lifespan and maintenance requirements

Consider the expected lifespan of the system and its maintenance needs. Some applications require gearboxes with long lifespans and minimal maintenance. The selection of the spindle, lubricant, and size is significantly influenced by these factors.

Planning Advice for Spindles: There are calculation methods to determine the theoretical lifespan of ball screws accurately. For trapezoidal screw drives, only empirical values are available.

Screw jacks are generally considered maintenance-intensive among electromechanical lifting elements, mainly due to the need for regular re-lubrication. In contrast, the MINI is equipped with lifetime lubrication and is generally considered low-maintenance. You can find more on the topic of maintenance here.

7. Assembly requirements

Clarify the specific requirements for assembly, especially regarding attachment points, mounting methods, and space availability. Various mounting heads are available for each lifting element. Heads with rod eyes allow a pivoting movement in one axis, while heads with ball joints also enable movement in the radial direction.

If space is very limited and a standard lifting cylinder or screw jack is not feasible, the MINI or the linear chain might solve the problem. The MINI, with its integrated hollow shaft motor, achieves high power density in a compact space. The linear chain does not waste space behind the drive housing, as the chain can be stored coiled.

8. Power supply

Check the available power supply and ensure that the screw jack is compatible with it. Most industrial motors are equipped with 3x 230V / 3x 400V. If 24VDC or 48VDC motors are needed (e.g., for autonomous transport systems), the motor's power capacity should be the focus of your evaluations. Motors with 1x 230V (AC) are more of an exception.

9. Safety requirements

Consider safety aspects, especially if the screw jack is used in safety-critical applications. This might necessitate selecting jacks with integrated safety features. Screw jacks are particularly popular in stage construction because trapezoidal lead screws offer self-locking capabilities and screw jacks can be equipped with various additional safety functions with minimal effort.

Planning Advice for Safety Requirements: For stage technology, refer to the relevant standards for important guidelines on required safety measures for lifting devices used in stage construction.

10. Costs

Finally, the cost of the screw jack and its installation should fit within the budget. Consider both the initial purchase price and potential operating costs.