摘要:
A method for determining the active power (P) of asynchronous electric motors of winning and conveying equipment in underground mining. According to the invention, particularly easy and accurate determination of the instantaneous active power of the motors is obtained by storing the individual motor characteristic (P(n); M(n)) of each motor in a computer, by detecting the instantaneous speed (n, n') of the motor with the aid of a tachometer and by comparing this speed with the characteristic stored in the computer, the active power being derived from the torque value or power value assigned to the detected instantaneous speed, as stored in the computer. This particularly rapid and simple calculation of the power value does not require any readings to be taken at the power supply to the motors.
摘要:
A protection circuit for intrinsically safe electromagnetic actuators operating on the voltage from a power unit (1) approved for underground mining, for switching electrohydraulic valves (5) in underground mining, comprising at least two spaced-apart short-circuit means (14, 16 or 16A) connected in parallel with the electromagnetic actuator coil (11) for short-circuiting the coil in the event of a reversal of the coil voltage. According to the invention, at least one of the short-circuit means comprises a short-circuit semi-conductor switch (16 or 16A) and a voltage-reversal detecting circuit (30) for activating the short-circuit semiconductor switch (16).
摘要:
The invention relates to a mining electromagnet for the switching of hydraulic pilot valves or main control valves used in underground mining operations, with a coil which can be connected to an intrinsically-safe power unit, with an armature which can be displaced by application of current to the coil and with an electronic control device 20, by means of which the current which is conducted to the coil can be set during the drawing-in phase of the armature to an excitation current, and in its holding phase can be set to a holding current which is lower than the excitation current. According to the invention, a storage means 24, 25 is allocated to the mining electromagnet 2, 3, said storage means being capable of being charged with the power unit voltage of the power unit 23, and switched in series with the power unit by the initiation of a switching process for the electromagnets, and which, by means of its discharge during the duration of the drawing-in phase, causes an increase in the voltage imposed at the coil of the electromagnet which is to be switched. In preferred embodiments of the invention, twice as many electromagnets can be switched in the same time and supplied with one common power unit.
摘要:
The invention concerns a mining lamp 1 with a signal display. The mining lamp 1 is characterised in that it includes a large number of light diodes 3 and a control device 9, by means of which the light diodes 3 can be controlled individually or in groups, in order to display symbols, flashing signals, letters, text, patterns and/or similar.
摘要:
An electro-hydraulic assembly for use in underground mining is disclosed. The assembly includes a hydraulic component, such as a valve block for an underground self-advancing roof support, as well as actuators and/or sensors which have a housing and can be connected or are connected via a data-transmission system to a control unit. A function (e.g. withdrawing the support, setting, advancing, or the like) can be activated at the hydraulic component by each actuator, and/or a hydraulic state associated with a measuring point of the hydraulic component or another measured variable associated with the self-advancing roof support can be measured by each sensor. A reader unit is associated with each actuator and/or sensor in its respective housing, and an information element or transponder is associated with the hydraulic component for each function, each control valve, or each measuring point. The information in the information element or transponder is readable by the reader unit and transmittable to the control unit. All the control valves and sensors are coded for the control unit and the control unit can associate each actuator with its corresponding control valve. In this way, it can be known which actuator is associated with which function of the hydraulic component and connection faults can be avoided.
摘要:
An intrinsically-safe battery power supply for electrical equipment in underground mining and in other areas exposed to the danger of explosion is disclosed. The power supply includes at least one chargeable storage battery cell disposed in a battery housing. At least one storage battery cell comprises a chargeable lithium storage battery cell and the battery housing is configured to be pressure-resistant and to receive all lithium storage battery cells in a manner so as to be protected from explosion. The pressure-resistant configuration of the battery housing enables the use of lithium storage battery cells in underground mining. Once the battery power supply fulfils all requirements of ignition protection certification, even modern types of lithium storage battery cell can be disposed in the battery housing.
摘要:
A piezoelectric actuator unit 10 for valve switching has a piezoelectric element changing its size on the application of a control voltage for switching the valve. So as to ensure a Totmann (safety) function of the valve and a fast return of the piezoelectric element into its initial position, the piezoelectric actuator unit 10 comprises a discharge circuit with at least one discharge element 21, 31 connected to the piezoelectric element 11. Discharge of the piezoelectric element is effected when the actuator is in its initial, safe position. The discharge circuit has to be switched actively so as to be able to exert a maximum stroke with the piezoelectric actuator.
摘要:
A drive system for driving a flexible elongate member such as a haulage chain for a mineral mining machine or scraper-chain assembly of a scraper-chain conveyor of a mineral mining installation employs main and auxiliary drive units each equipped with an electric asynchronous motor drivably connected through a gearing assembly to a sprocket around which the chain or scraper-chain assembly is entrained. The gearing assemblies each employ a multi-disc clutch which is subjected to variable loading pressure and slippage by means of a valve actuated by electrical signals provided by an electronic controller. Each clutch acts through gears on a ring gear of planetary gearing and the ring gear wheel is subjected to a controlled supportive torque. The electronic controller is designed to actuate the associated valves to adjust the clutches to balance loading on the motors of the units. During a start-up phase the controller functions to ensure the force transmitted to the chain or scraper-chain assembly slowly and progressively increases and sudden loading is avoided. In the event of overloading the controller causes the valves to actuate the clutches rapidly to allow the ring gears of the planetary gearings to rotate freely to disconnect the drive.
摘要:
An intrinsically-safe battery power supply for electrical equipment in underground mining and in other areas exposed to the danger of explosion is disclosed. The power supply includes at least one chargeable storage battery cell disposed in a battery housing. At least one storage battery cell comprises a chargeable lithium storage battery cell and the battery housing is configured to be pressure-resistant and to receive all lithium storage battery cells in a manner so as to be protected from explosion. The pressure-resistant configuration of the battery housing enables the use of lithium storage battery cells in underground mining. Once the battery power supply fulfils all requirements of ignition protection certification, even modern types of lithium storage battery cell can be disposed in the battery housing.
摘要:
A housing cover for a solenoid housing operable for accommodating solenoids for switching hydraulic directional valves is disclosed. A housing cover box has a plurality of side walls, a top side, and an open bottom side, with first and second actuating guides for guiding first and second solenoid control push rods being located on the top side. A plug connector is located between the actuating guides. At least one screw clearance hole is located at each corner of the housing cover box for locating a screw for joining the housing cover box to the solenoid housing. A sealing plate is located between the housing cover box and the solenoid housing, and at least one mounting foot is located at a corner and on a bottom surface of the housing cover box. A tubular spigot is aligned with and extends each screw clearance hole.