Voith Turbo Safeset AB
Torque Limiting Couplings

Torque Limiting Couplings and
Connection Couplings in Mining

Most applications in mining require heavy investments in machinery and technology. High demands in personal security is mandatory. Big and expensive machinery means high downtime costs. It puts extreme performance demands on the machinery and above all, on the driveline. It is important to protect the driveline from overload caused by unexpected problems in the production process.

Contact

Voith Turbo Safeset AB
Rönningevägen 8
82434 Hudiksvall, Schweden

Tel. +46 650 540150
Fax +46 650 540165 sales.safeset@voith.com

Protect and enhance your machinery

Regardless of the application, the challenges in mining are similar. The key to reliability and efficiency in mining is a smooth and problem free production process, with a minimum amount of downtime. In mining applications, torque limiting couplings protect big and heavy machinery by releasing or slipping at a very precise set torque. Connection couplings are used for torque transmitting, often in conveying and excavating.

SafeSet torque limiting couplings and connection couplings from Voith:
  • Prevent damage of machinery, which leads to financial savings
  • Increase production uptime and minimize loss of production, which also increases profit
  • Lengthen the life-span of the machinery by avoidance of overload cases
  • Provide a backlash free connection

Product range

Publications

Torque limiting Couplings
(SafeSet, SmartSet, AutoSet)
Improved Productivity in Mining.
SafeSet Torque limiting Couplings and Connection Couplings

Mining Applications

Crushers

Cone/Gyratory Crusher

Uncrushable objects in the crushing chamber cause the crusher to stop. The inertia of the driveline and motor continue to deliver torque, which can cause severe damage or overheating.

Challenge
If the cone suddenly stops, high torque and overheating will cause damage to all the driveline components and lead to a long stop in production.

Solution
Replacing belt drives with a direct drive. Installing a SafeSet torque limiting coupling deals with torque overloads safely and quickly. This ensures all parts of the driveline are protected.
Voith can also provide flexible couplings to cope with misalignments and torsional vibrations

Sizer/Roller Crusher

The rollers can easily become blocked by uncrushables, however the inertia in the driveline continues to produce torque. This can result in major damage to the driveline and motor and cause production downtime.

Challenge
When the rollers are jammed the overload continues until the driveline or motor break down, causing major damage and production downtime.

Solution
SafeSet torque limiting couplings control the torque and absorb shock loading, protecting the driveshaft and motor. SafeSet instantly disconnects the inertia from the crusher.
Replacing a traditional mechanical coupling with a hydraulic connection coupling, facilitates service and maintenance, for example changing the transmission.
SafeSet Application:
Gyratory Crusher
SafeSet Application:
Hydrocone Crusher
Mills

Ball/Sag/AG Mill, Roller Press HPGR/HRC

The dual pinion drives in a mill can come out of sync due to power problems, or disturbances in the motor control system. Another common problem is frozen charge that has built up inside. This might cause torque peaks or consequential damage. Synchronization problems or jammed rollers in a roller press, can cause an overload and consequential damage.

Challenge
In a mill torque peaks can occur during startup if frozen or solidified minerals have built up inside, or if the dual pinion drives do not work simultaneously.
In a roller press, the rollers can come out of sync or become blocked by uncrushables, however the inertia in the driveline continues, producing a torque overload.

Solution
SafeSet torque limiting couplings protect the driveline from torque peaks, when there are synchronization problems or overloads caused by a blockage or frozen charge.
A hydraulic connection coupling instead of a mechanical joint, in a roller press, facilitates service and maintenance.
Tunnel Boring Machines

Tunnel Boring Machines

Due to the varying hardness of soil and rock layers, torque peaks are hard to predict. Excessive torque levels can occur particularly during start-up and commissioning.

Challenge
If the large pinion-shaped cutter is blocked, vital parts of the transmission and the driveline components are at risk of being destroyed, leading to machine stoppage.

Solution
Installation of SafeSet torque limiting couplings either on the back of the motors or between the hollow shaft and the torque shaft, or in line with the drive units.
SmartSet couplings can be installed to prevent the drive from disengaging completely at short torque peaks. The couplings slip and only release at longer durations, this reduces downtime and ensures safe performance.
SafeSet Application:
Tunnel Boring Machines
Conveyors

Belt Conveyors, Apron Feeders, Chain Conveyors (AFC)

AFC’s and apron feeders can suffer downtime due to conveyor chain breakage or driveline failure. This is often a result of torque overloads caused by material getting stuck.

Challenge
An overload can cause damage to the drive chain and extensive downtime, as the conveyor needs to be cleared of built up rock or coal.

Solution
SafeSet and SmartSet torque limiting couplings protect the chain by slipping and limiting the torque peaks. The coupling is designed to either release at longer durations, or not release at all, to prevent the drive from disengaging completely.
For belt conveyors (overland conveyors) mechanical joints can be replaced with hydraulic connection couplings. This increases accessibility of the driveline and minimizes downtime due to service and maintenance.
SafeSet Application:
Armored Face Conveyors.
Excavators

Bucket Wheel Excavators, Continuous Miners, Shearer Heads

The cutter head can come to a sudden stop when it encounters hard material or gaps. The system inertia continues until something breaks along the driveline.

Challenge
If the motor or inertia continues after the cutter head stops, the torque creates a shock load for the gear box and could cause significant damage and downtime.

Solution
SafeSet or SmartSet torque limiting couplings absorb the torque by slipping and protecting the gear box during high peaks.