Speed and position sensors for mine hoists and elevators
- Bureau of Mines, Pittsburgh, PA (United States). Pittsburgh Research Center
Mine hoist and elevator safety devices are tested periodically. However, periodic testing cannot ensure that a recently tested safety device will function properly when called upon. Ideally, the condition of critical safety devices should be continuously monitored but this is either impractical or impossible. The US Bureau of Mines is conducting research on the more practical approach of continuously monitoring the speed and position of the shaft conveyance. By monitoring the depth and speed of a conveyance and comparing the result with the appropriate speed curve, an operator can be warned before the curve is exceeded and may then take appropriate action. This information will also detect other hoisting malfunctions such as motor or brake problems. Monitoring the actual cage position during operation and comparing this with the position indicated by the winding drum will indirectly enable the detection of rope slip for friction hoists and slack rope in drum hoists. Hoist systems presently in use are typically not equipped with appropriate devices for directly monitoring actual cage speed and position. Conventional overspeed protection for a mine elevator is currently done by a centrifugal governor. However, a mechanical governor is not capable of determining if the speed curve is changing with respect to the cage position in the hoisting cycle. Therefore, another means of sensing cage speed is needed. This paper discusses several types of speed and position sensors, and advantages and disadvantages of each. The research suggests methods to monitor actual speed and position of the cage, which can be very significant in preventing overspeed accidents resulting from safety device failures in mine hoists and elevators.
- OSTI ID:
- 427901
- Report Number(s):
- CONF-9510203-; TRN: IM9708%%228
- Resource Relation:
- Conference: IEEE/Industrial Application Society conference, Orlando, FL (United States), 8-12 Oct 1995; Other Information: PBD: 1995; Related Information: Is Part Of Conference record of the 1995 IEEE Industry Applications Society 30. IAS annual meeting. Volume 3; PB: 961 p.
- Country of Publication:
- United States
- Language:
- English
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