Home Case Studies Incremental heavy-duty encoders defy the most adverse conditions in mining operations to ensure reliable speed control
The skip-car control mechanism utilised to date included two mechanical, geared cam limit switches that are time consuming to program. Upgrading to meet modern demands required suitable components for measuring actual values that are not only characterized by their high accuracy and functional reliability, but are also easy to program. Hübner Giessen replaced one of the geared cam limit switches with a series FG 4 K incremental encoder and an AMS 4 K type absolute encoder with integrated SSI interface.
Incremental heavy-duty encoders defy the most adverse conditions in mining operations to ensure reliable speed control
Pilger mill in tube rolling mills - hot and cold pipe detection
- Direct hollow shaft attachment to the motor shaft
- Optimum compensation for oscillation and shock loads
- Insulated attachment with hybrid bearings and customized torque bracket
- Effectively avoid destructive shaft currents
Conveyor drive station in open cast mining.
Challenges
- Conveyor belt components in particular must be able to permanently withstand the powerful effects of oscillation and vibration. These not only result from the length of the conveyor system or the material being transported. Other causes can be traced back to the design of the drive station, the drive solutions, transfer points, the condition of the belts and similar reasons. The inverter-controlled drives can cause shaft currents that place a heavy strain on the bearings of the encoder system and even destroy them over time. Then there are external factors such as dust, dirt and moisture as well as extreme temperature fluctuations depending on the time of day, and extreme cold or heat depending on the region where the conveyor system is installed.
Incremental encoder FGHJ 5 with special hybrid bearings in a heavy duty housing.
Solution
- To ensure optimum compensation for the extreme oscillation and vibration loads we recommended fitting hollow-shaft encoders in conjunction with torque brackets. The heavy duty encoder FGHJ 5 has hybrid bearings; when fitted in combination with the insulated torque bracket and, if required, an insulated adapter shaft they can effectively prevent the negative influence of shaft currents on the service life of the encoders. In line with requirements it is possible to augment the incremental encoders with an overspeed switch integrated in the second terminal box to guarantee additional protection against overspeeds and underspeeds and safeguard special safety-related functions.
Products and Accessories
Case Study Number
- TP3
Challenge
- The increasing flexibility of production lines requires a high adaptability of sensors. Continually changing object geometries, different temperatures and very high radiation or surrounding temperatures are no rarity.
- In a pilger mill those rough conditions can be found, among others in the production of seemless steel pipes. The raw steel blocks, each weighing a few tons are heated up first in a round oven at a temperature of 1300 °C.
- After descaling of the surface, the steel block is prepunched in a hole press with a strength from a converted 2000 t. In the next sloping rolling mill the growing pipe rotates between two rollers that are positioned at an angle to each other. The punching is widened to the size of the mandrel diameter.
Previous solution / Competitor product
- N/A
Solution
- The sensor that was installed at this application is the HMD OKA 2038.38 G with tube OL 19.
- The signal of the infrared sensors controls the movement of centering device and abutment. The point of view is restricted by the tube and prevents disturbances by steam in the cooling phase.
- An optimum adaptation to the operating conditions is given due to the adjustable response temperature. The HMD with self-learning response temperature (Auto-Teach function) is suited to continually changing conditions.
- The compact sensor with a stainless steel housing can withstand surrounding temperatures of up to 75° C. The use of a cooling jacket raises this up to 200° C.
- Alternatively sensors with fibre optic cables are available which permit an application at ambient temperatures up to 600° C without cooling.
Customer Benefits
- Maintenance-free
- High temperature stability
- Recognition of hot objects at big distances
- Self adjustment with Auto-Teach or step switch for the response temperature
Product Part number
- OKA 2038.38 G
Brand
- Proxitron
Accessories
- Piros swivel stand HM2
- Tube OL 19
- Pilot light unit (for alignment) DAK 308 + OL 26
- Different cable lengths (e.g. 15 m)
Customer Testimonial
compared to previous solution or competition
Case Studies
Other Solutions in Hot Rolling Mills
Sample case study title lorem ipsum here
Short description of the problem solved, maybe include the client name.
Sample case study title lorem ipsum here
Short description of the problem solved, maybe include the client name.
READ MORE
Sample case study title lorem ipsum here
Short description of the problem solved, maybe include the client name.
READ MORE
