Contents
High-Performance Screw Jack
Basics
1. What's a High-Performance Screw Jack (HMC)?
A high-performance screw jack (HMC) is a specialized type of worm screw jack designed for applications requiring high loads and speeds. These screw jacks are characterized by their robust construction, high load capacity, and performance.
The HMC screw jack is a mechanical device that converts rotational motion into linear motion. It is commonly used in various applications to lift, lower, or move objects horizontally.
The core components of a screw jack typically include a steel spindle (a long rod with a threaded shaft) and a nut made of bronze, cast iron, or plastic (a matching threaded section). When the spindle is rotated, the nut moves along the spindle. Conversely, if the nut is rotated, the spindle extends or retracts. This results in linear movement, which can be used for lifting or lowering loads or moving objects.
HMC Basic version
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HMC Traveling nut version
To learn more about the difference between the basic version and the traveling nut version, visit: How screw jacks work and where they are used (grob-antriebstechnik.de)
2. What distinguishes High-Performance Screw Jacks from conventional worm screw jacks?
High-performance screw jacks differ from standard screw jacks in three main aspects:
1) Worm Gear: To increase load capacity, the worm gear is designed to be longer. Particularly, the basic version with a traveling spindle benefits from the extended nut thread in the worm gear.
2) Oil Filling: Each HMC unit features a dual-chamber lubrication system. The gearbox housing is generally filled with oil, which significantly aids in transferring heat from the friction points at the worm gear to the housing surface. The oil filling also allows for a drive speed of up to 3000 RPM.
3) Housing with Cooling Ribs: Enlarging the housing surface with cooling ribs improves heat dissipation to the surrounding environment.
These three factors result in greater load capacity at higher speeds and increased duty cycles. The reduced power loss in the worm gear consequently leads to less frequent failures due to overheating.
HMC from the inside
3. When should a High-Performance Screw Jack (HMC) be chosen?
A high-performance screw jack (HMC) is typically suitable when high speed is required in combination with trapezoidal screw spindles and high load capacity. This is the case when self-locking is needed and a higher pitch cannot be used to increase speed. The higher drive speed of 3000 RPM enables speeds of up to 50 mm/s with standard trapezoidal threads.
4. When is a High-Performance Screw Jack (HMC) a poor choice?
The majority of applications can be handled with cubic or classic screw jacks. If the application has a duty cycle of less than 20% and operates at speeds of 25-30 mm/s, the HMC may be an unnecessary overdimensioning.
5. Features of High-Performance Screw Jacks
High load capacity
A key feature of high-performance screw jacks is their ability to move heavy loads. They can lift or shift tons of weight without losing performance.
High speed
Although designed to handle high loads, high-performance screw jacks can also achieve high speeds, especially when compared to conventional screw jacks.
Precision
Despite their power, high-performance screw jacks can offer high precision in movement control. This is crucial for applications where accuracy is required.
Robust construction
They are often made from high-quality materials such as steel or alloys to withstand loads and ensure a long service life.
6. Applications of High-Performance Screw Jacks
Heavy industry
High-performance screw jacks are used in heavy industries, such as steel mills, shipbuilding, and mining, to move heavy loads and materials.
Automatization
In large manufacturing plants and robotic systems, high-performance screw jacks are used to lift, position, and move workpieces.
Aircraft manufacturing
In aircraft construction, high-performance screw jacks are used to lift and assemble wings or fuselage sections.
Energy generation
In power plants, particularly in hydroelectric and wind power plants, high-performance screw jacks are used to move turbines and generators.
Heavy-duty transport
In the field of heavy-duty transportation, high-performance screw jacks are used in specialized vehicles to transport heavy construction machinery or components.
Scaffolding
High-performance screw jacks are used in scaffolding for precise lifting, leveling, and load distribution. They enable height adjustments, ensure stability on uneven surfaces, and provide temporary structural support.
Defense
Positioning heavy equipment like radar systems or missile platforms.
7. Pro and Cons
Cons
✘ Cost: High-performance screw jacks are generally more expensive than smaller or less powerful models.
✘ Space requirements: They need sufficient space for their stroke, which can be problematic in confined or tight spaces.
✘ Maintenance: Like all mechanical devices, high-performance screw jacks require regular maintenance to ensure optimal performance and longevity.
Pros
✔ High Load Capacity: High-performance screw jacks are specifically designed to lift or move heavy loads. They can handle tons of weight, which is beneficial in various industrial applications.
✔ High Speed: Compared to some other types of jacks, high-performance screw jacks can achieve high speeds without losing performance. This is important when fast movements are required.
✔ Precision: Despite their high power, high-performance screw jacks often offer high precision in motion control. This is crucial for applications where accuracy is essential.
✔ Robust Construction: High-performance screw jacks are typically made from high-quality materials such as steel or alloys to withstand loads and ensure long lifespan.
✔ Versatility: They can be used in a wide range of applications, including heavy industry, automation, power generation, and more.
✔ Increased Safety: The combination with trapezoidal threads generates self-locking and prevents "slipping" in case of motor failure.
FAQs about High-Performance Screw Jacks
What are the distinguishing features of high-performance screw jacks?
High-performance screw jacks are designed for demanding applications, providing high durability, precision, and efficiency in industrial environments.
What are the benefits of high-performance screw jacks?
They enable heavy loads, high speeds, and precise positioning. The robust construction ensures long life under extreme conditions.
In which industries are high-performance screw jacks used?
These gears are used in automation, mechanical engineering, robotics, and other industrial sectors where high performance and reliability are required.
What are the main/general differences between cubic, classic, HMC, KH?
- Cubic & Classic: primarily external differences. A matter of personal preference regarding which one is preferred. Performance data is nearly identical.
- HMC: Standard up to 3000 rpm input speed, with oil filling and cooling fins - explicitly higher dynamic load capacity.
- KH: explicitly high dynamic capability, but load capacity decreases to a maximum of 90 kN.
Want to know more?
Dimensioning of Screw Jacks
Dive into the world of engineering with our article on 'Dimensioning of Screw Jacks' and learn how to calculate key parameters such as motor power, rotational speed, bending, and pitch angle to ensure precise and efficient lifting movements for your application.
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