Analysis of Technological Development Trends in the Industrial Brake Industry

(1) Brake Drive Method

The main drive method of the brake is electric hydraulic actuators, followed by AC or DC electromagnets, and a small number of hydraulic and pneumatic devices. Due to the advantages of electric hydraulic actuators such as low impact, low working noise, simple control, long service life, and low operating costs, they have become the mainstream product in high-speed shaft industrial brakes. In the field of safety brakes, hydraulic-driven brakes are predominant.

(2) Functions of the Brake

With the development of equipment towards larger, super-large, specialized, and highly automated directions, brakes are rapidly evolving towards heavy-duty braking conditions, multifunctionality, intelligence, and maintenance-free aspects. Heavy-duty braking conditions are to meet the braking requirements of large and super-large heavy-duty mechanisms; multifunctionality mainly includes brake release interlock function, manual release function, pad wear limit positioning (interlock) function, automatic wear compensation function, etc.; intelligence refers to the introduction of digital technology and computer technology into the control system; maintenance-free means turning functions that require manual adjustment into automatic adjustment functions while achieving high reliability of brake action and performance. In addition, real-time maintenance of industrial brakes through remote monitoring is also an important development direction for brakes.

(3) Safety Brakes

Safety brakes are mechanical brakes set on the final shaft of the transmission mechanism (drum shaft), generally used only on important lifting mechanisms (such as crane lifting mechanisms, boom pitching mechanisms, and inclined belt conveyors, etc.). Since the 1980s, with the rapid development of lifting and unloading machinery towards larger, super-large, specialized, efficient, semi-automatic, and automated directions, the application of safety brakes has also developed rapidly. Currently, safety brakes are widely used in large port specialized unloading machinery, and their application is being promoted in large specialized lifting equipment (such as power station gate machines, casting cranes, and cable cranes' lifting mechanisms) and inclined belt conveyors.

Before the mid-1990s, safety brakes in China were almost blank. After the mid-1990s, the rapid improvement of manufacturing levels of large, specialized port unloading machinery and the rapid growth of market demand promoted the rapid development of safety brakes in China. In just over a decade, the technology of safety brakes in China has approached or reached international levels, and the variety of products is also continuously increasing.

(4) Friction Materials

Friction materials, which are composite materials containing multiple components, are one of the core technologies of industrial brakes. The friction coefficient is one of the main properties of friction materials, closely related to the surface condition of the friction material, medium, or environmental factors. The quality and friction performance of friction materials directly affect the performance and safety of the brake.

Before the 1990s, the main friction material used was asbestos brake linings. Due to asbestos being a carcinogen, non-asbestos organic (NAO) composite friction materials quickly replaced asbestos friction materials. With the heavy-duty braking conditions of brakes, the accompanying brake pads are required to have high temperature resistance, wear resistance, high and stable friction performance, short maintenance time, and long service life. Semi-metallic resin-based friction materials and powder metallurgy friction materials have gradually become mainstream products in the market. Currently, ceramic-based composite friction materials are gradually being widely used due to their excellent high-temperature friction performance and suitability for higher specific pressures.

(5) Reliability and Lifespan of Brakes

Before the 1990s, brakes were treated as consumables. With the significant improvement in the technology and quality level of industrial brakes, industrial brakes are now developing towards high reliability and lifespan comparable to that of main components.