Basics
Here you'll learn everything you need to know about electromechanical drives, including Screw Jacks, Linear Chains, Electric Cylinders, MINI Actuators, and more. We explain what these products are, how they work, and the crucial role they play in various applications.
FAQs about the Basics
A Screw Jack is a combination of a spindle (screw) and a nut (worm gear or traveling nut) that converts rotational motion into linear motion through a worm gear drive.
How screw jacks work and where they are used - GROB GmbH chevron_rightA Linear Actuator converts rotational motion into linear motion. It is powered by electric motors. However, linear movements can also be achieved through hydraulic or pneumatic actuators. Electric Linear Actuators are used for more precise movements.
A Linear Chain is a type of chain that can be both pulled and pushed. When the chain links are pushed together, they stay stable and rigid, allowing you to move things forward. It’s often used in machines to lift or push objects.
What a Linear Chain is and where it is used - GROB GmbH chevron_rightThe chain of the Linear Chain consists of links that rest on the shoulders and pins of the succeeding link. The chain of the Tower Chain is constructed with U-shaped chain links, providing greater stability and enabling unguided strokes of over 4m.
An Electric Cylinder is an electromechanical actuator that operates linearly and is powered by electrical energy to generate motion.
What an Electric Cylinder is and where it is used - GROB chevron_rightBasic Version: The spindle itself performs the axial movement.
Traveling Nut Version: The spindle remains stationary in space but rotates. The nut then moves up and down on the spindle.
- Cubic & Classic: primarily external differences. A matter of personal preference regarding which one is preferred. Performance data is nearly identical.
- High-Performance Screw Jack: Standard up to 3000rpm input speed, with oil filling and cooling fins - explicitly higher dynamic load capacity.
- High-Speed Screw Jack: explicitly high dynamic capability, but load capacity decreases to a maximum of 90kN.
In standard applications, Linear Chains can be operated with a speed of 250mm/s. Special applications have already been implemented with speeds exceeding 800mm/s.
- Standard gearboxes with standard trapezoidal threads achieve efficiencies between 25-35%.
- Increasing the pitch makes the thread slip more easily, thus increasing efficiency.
- The combination with a ball screw can also achieve an efficiency of up to 50%.
- Best combination: bevel gear lifting drives with ball screws, which achieve over 80%.
Self-locking refers to the "non-slip" behavior of spindle-nut systems without external force. The degree of self-locking is influenced by the material pairing, the pitch angle, and the lubrication.
Yes, depending on the proximity to the product, the chain can also be completely made of stainless steel.
No, within the buckling range, Linear Chains can also be used without guidance.
Higher efficiency, higher speeds, precise theoretical calculation of service life
We always recommend using our standard link to connect your load. Utilize all the holes to ensure proper loading of the chain. Dimensions for the front link can be found here: General Catalog
No, you should provide a brake on the motor.
In our standard range, we adhere to military standards: -20°C to +60°C.
There's no calculation basis for this. Tests have shown that for standard chains, 250,000 cycles, and for hardened chains, 1,000,000 cycles represent realistic values.
The duty cycle (ED) indicates how long an electromechanical drive can operate within a given time period without overheating. It is typically expressed as a percentage and refers to a 10-minute cycle.