Extremultus Technical Q&A (Basics)

Q. “What are the technical reasons why Extremultus is regarded as ‘highly efficient (98% or higher)’?”

A. Extremultus is characterized by a highly rigid, low-elongation tension member construction, which significantly reduces energy losses caused by bending deformation. In addition, the surface materials are optimized for friction conditions with the pulleys, effectively minimizing slip-related losses.

Q. “How should the tension member be selected?”

A. The tension member is a critical element that determines the belt’s elongation behavior and load-carrying capacity.

In general:
• Polyester tension member: well-balanced and suitable for general-purpose applications
• Aramid tension member: low elongation for high-load and high-precision applications
• Polyamide sheet tension member: for applications requiring dimensional stability and impact resistance

This is the basic guideline for selection.

Q. “How does belt elongation (creep) affect operation?”

A. Excessive belt elongation can lead to slip and speed fluctuations due to reduced tension. Thanks to its tension member design, Extremultus suppresses both initial and long-term elongation, ensuring high speed stability.

Q. “What is the basic concept behind tension design?”

A. It is important “not to apply more tension than necessary.” Excessive tension increases bearing loads and shortens belt service life. The basic approach is to calculate and set the minimum required tension based on the required torque, coefficient of friction, and pulley diameter.

Q. “How does pulley diameter affect performance?”

A. The smaller the pulley diameter, the more frequently the belt bends, increasing internal losses and fatigue. While Extremultus is suitable for small pulley diameters, selecting the largest possible diameter improves both service life and efficiency.

Q. “How should the coefficient of friction be considered?”

A. A higher coefficient of friction is not always better. Excessively high friction can cause heat buildup and wear, so it is important to select an appropriate surface material (such as Elastomer G or leather) according to the application.

Q. “What are the performance differences between surface coatings?”

A.
• Elastomer G: high wear resistance and stable friction characteristics
• Leather: high friction and excellent noise-reducing properties

Selection should be based on requirements for noise reduction, wear resistance, and grip.

Q. “What design points require attention in high-speed operation?”

A. In high-speed operation, reduced contact pressure due to centrifugal force and vibration become critical issues. By selecting a belt with a high-rigidity tension member and maintaining proper tension settings and pulley accuracy, stable operation can be achieved.

Q. “What considerations are necessary for applications with shock loads?”

A. For applications involving frequent start-stop cycles or shock loads, selecting a structure with high shock-absorbing capability and setting the tension slightly lower helps reduce damage to the tension member.

Q. “What are the key design factors for live roller applications?”

A. In live roller applications, a consistent coefficient of friction and stable tension are essential. Due to its low elongation, Extremultus minimizes speed variations even during long-term operation.

Q. “Is tangential drive (twisted use in the axial direction) possible?”

A. Yes. Extremultus combines flexibility against twisting with dimensional stability, making it suitable for tapered cone drives and tangential drive applications.

Q. “How should belt width be selected?”

A. Belt width is determined based on the required transmitted power and permissible tension. By ensuring an adequate safety factor while avoiding excessive width selection, an optimal balance between cost and efficiency can be achieved.

Q. “Do temperature and humidity affect performance?”

A. In high-temperature environments, the properties of rubber-based surface materials may change, while in low-temperature environments, flexibility may decrease. Selecting materials suitable for the operating temperature range is essential.

Q. “Does bonding quality affect performance?”

A. The bonded joint is the area where stress is most concentrated within the belt. By following correct bonding methods and conditions, strength and service life equivalent to the belt body can be ensured.

Q. “In what ways can Extremultus be considered long-lasting?”

A. Low internal losses, a low-elongation tension member, and optimized friction design reduce wear, heat generation, and fatigue. As a result, readjustment and replacement intervals can be significantly extended.