The rumbling of mining trucks presents the growing demand for mining today. The 7×24 roar that can often be heard in most mining companies’ sites is backed by the efficient operation of mining equipment. Here, the reliability and stability of any piece of equipment is crucial – because any unexpected downtime can become a production or operational accident.
In the face of such a ‘mountain’, Timken, as a global leader in mining truck bearings, how to deal with it?
A hundred years of co-operation to build a smooth road
The weight of a fully loaded mining truck is not comparable to that of many other construction vehicles; and the environment in which mining trucks are transported is also more challenging due to the ruggedness of mining roads and the seriousness of environmental pollution. Under such conditions, the main support of mining trucks – wheel-end tapered roller bearings – must withstand multiple abrasive particles, heavy loads, low rotational speeds and other complex and severe tests.
Through more than 100 years of cooperation with domestic and foreign original equipment manufacturers, Timken has been providing customers with tailored solutions for mining truck bearings based on a deep understanding of wheel-end bearings and planetary wheel bearings for wheel-side reduction gears. 125 years of application experience has made Timken a trusted partner for the world’s leading equipment manufacturers.
Skillful solutions
‘Silky-smooth’ response to ‘abrasive particles’ In the mining environment, mine trucks travel on roads filled with abrasive particles. These abrasive particles enter the bearings, creating craters on the bearing raceway surface, which can cause rapid spalling of the raceway surface over long periods of time.
Timken’s carburising heat treatment technology can inhibit and slow down the expansion of cracks; at the same time, Timken’s diamond-like surface coating technology for rollers not only achieves ultra-precise surface finish and increases self-repairing ability of the raceway, but also improves the bearing’s wear resistance to cope with heavily contaminated working conditions.
Comparison of standard bearings (left) and anti-friction bearings (right) under poor lubrication test conditions
Full load bearing ‘high load’
Mining trucks loaded with ore are prone to shaft deflection, and the extra axial force under turning conditions tends to generate high internal stresses in the bearings – all of which severely test the load-bearing capacity of truck bearings.
The enhanced internal geometry of Timken’s tapered roller bearings minimises boundary stresses and distributes loads evenly, resulting in higher power density and longer bearing life in a limited design space.
Steady fit for ‘low speed
Unlike cars running on the highway, most of the mining trucks rotate at only a few tens of revolutions when they are loaded with ore, which is a typical low-speed working condition. Low-speed conditions make it difficult to form a thick enough lubricant film, which leads to direct contact between the rolling elements and the raceway surface, causing early spalling of the raceway surface after a long period of time, resulting in early damage to the bearing. Timken strengthened tapered roller bearings surface finish, reducing the separation of the raceway contact surface lubricant film thickness requirements, is conducive to prolonging the lubrication of poor working conditions of bearing life. In addition, the aforementioned diamond-like coating on the roller surface is also helpful in poor lubrication conditions.
Matching Wheels to Meet ‘Electrification
There is a growing demand for electrically powered wheel-side reduction mechanisms as opposed to mechanical wheels. For different tonnages of mining trucks, major OEMs are offering different planetary reduction solutions, such as planetary carrier outputs, toothed ring outputs, etc. The planetary wheel position is supported by a pair of bearings. The planetary wheel position is supported by a pair of bearings. The control of the tolerance zone and initial clearance of the inner and outer rings of the bearings facilitates a more even distribution of bearing loads and maintains a relatively consistent load zone for the bearings of the same planetary wheel during operation. On the other hand, in the first planetary wheel position, the bearing cage is often subjected to high centrifugal acceleration, which poses a considerable challenge to the strength and wear resistance of the cage.
Timken’s tapered roller bearings, spherical roller bearings and cylindrical roller bearings with enhanced cage design can easily cope with high centrifugal acceleration, while Timken’s years of test data and special cage analysis software can provide customers with customised solutions.
Working together to create ‘green and smart mines’
As the world’s largest manufacturing country and the largest mineral consumption market, China’s total consumption of most minerals has reached 50% of the global total, and its economic development has a great dependence on mineral resources; at the same time, the mining process consumes a large amount of fossil energy, which is an important source of carbon emissions.
With the ‘dual carbon’ goal and the continuous development of AI technology, the construction of ‘green mines’, ‘smart mines’ a number of policies continue to be introduced –Zhejiang has required 100% construction of intelligent mines. Some professionals said that in this context, energy saving and emission reduction, new energy, digitalisation and intelligence have become the development trend of the sand and gravel industry. Mining trucks, as the main force of the open-pit mining industry, are imperative for energy-efficient and intelligent applications.
As a bearing manufacturer with more than 125 years of history, Timken will, as always, accurately understand customer needs, use its engineering advantages and global foresight to provide customised, targeted, and in line with the trend of the times manufacturing solutions for mining trucks, and work together with its partners to jointly enhance the business value and social value.