When the CNC system is started, press the external start button SB1, the relay RY1 is self-protected, and the LC1 and LC2 are simultaneously sucked, and the input unit starts to supply power to the CNC power supply unit. When the output voltage of the CNC power supply unit is normal, the PA and PB contacts are closed, so that the PAB is energized. At the same time, after the delay of about 05s by the action of TU1, RS1 and RS3 are successively energized to maintain the pull-in of RY1. When the CNC power supply is used. When the unit output is abnormal, the PA and PB contacts are disconnected, and the AL pulls in, so that RY1, LC1 and LC2 are successively released, the supply input power of the CNC power supply unit is cut off, and the alarm lamp P2 is turned on. Similarly, when the CN power supply unit needs to be stopped, simply press the stop button SB2 to release RY1, LC1, and LC2, and cut off the power supply to the CNC power supply unit.
Maintenance of the input unit During routine maintenance, when the CNC system cannot be started, it should be observed whether the power indicator P1 (green) on the input unit board is lit before the system is started. If it is not lit, check the outside. The power supply circuit, after confirming that the power supply is normal, has to check the +24V voltage regulator circuit on the input unit board. Usually, the breakdown of the transistor Q1 causes the fuse F3 to blow. If the green light of P1 is on, press the system start button SB1 at this time, and then observe whether the P2 red alarm light on the input unit board is lit. If there is no reaction when pressing SB1, the start and stop buttons are generally damaged or the connection is disconnected.
If the red alarm light is on when SB1 is pressed, the main power supply should be disconnected first, then the plug CP2 of the input unit and the CNC power supply unit should be unplugged, and the two points of CP2 should be shorted, and then SB1 should be restarted after power-on. If the red alarm light is still on, the PAB relay is generally damaged. If the alarm light does not illuminate, measure whether there is a 200V AC voltage output at the two points on the CP2. If there is no output voltage, it is usually caused by damage to the PY1, LC1 and LC2 relays. If there is an output voltage, it indicates that the fault point is on the CNC power unit. When the output voltage of the CNC power supply unit is +5V, 15V, and +24V, as long as one output is abnormal, the PA1 and PB contacts will be disconnected and an alarm will be generated. The failure of the power supply unit is usually caused by a +24V fuse blown due to a short circuit on the external line.
(Finish)
Generally have two kinds of structure: first half open, is composed of a rear cover plate and blades, the structure, the efficiency of the Impeller lower, in order to improve the efficiency to be matched with a seal ring which can adjust clearance; another half open, is composed of a front cover plate and blades. The application and closed the same impeller sealing ring, efficiency and closed impeller is basically the same as the blades, and in addition to transport liquid, also has back blade or vice impeller seal. The semi open impeller is suitable for conveying liquid containing solid particles, fibers, etc.. Semi open impeller manufacturing is difficult, low cost, and adaptability, in the oil refining and chemical industry with a gradual increase in the application of centrifugal pump, and for the transport of water and water approximation of the liquid.
Photo of our Impeller:
Open impeller
Only blades and blades to strengthen the reinforcement, no front and back cover of the impeller (open impeller blade number less 2-5). Impeller efficiency is low, the application is less, mainly used for conveying high viscosity liquid, as well as slurry liquid.
Blade of centrifugal pump impeller is generally backward curved blade. There are two kinds of cylindrical and twisted, the application of twisted blades can reduce the load of the blade, and can improve the suction performance of centrifugal pump, improve the anti cavitation ability, but the manufacture is difficult, the cost is higher.
Centrifugal pump for oil refining and chemical industry requires impeller for casting or whole welding seam welding of the integral impeller. Special centrifugal pumps for chemical use in the manufacture of metal materials (such as iron and its alloys), which are used in the manufacture of poor performance, such as iron and its alloys. The geometric accuracy and surface finish of the welded impeller are superior to the casting impeller, which is beneficial to the improvement of the efficiency of the centrifugal pump.
Shape classification
The shape of the blade centrifugal fan impeller has several single plate, arc type and wing type etc.. Airfoil blade has good aerodynamic characteristics, high efficiency, good strength and stiffness. The disadvantage is that the manufacturing process is complex, and when the transmission of high dust concentration of the gas, the blade is easy to wear, blade wear, the impurities into the blade, so that the impeller lost balance and vibration. The flat straight blade is simple, but the flow characteristics are poor, and the efficiency is quite close to the efficiency of the other working conditions when the flat curve is compared with the airfoil blade, and the efficiency is lower than the highest efficiency point.
Forward impeller
The front impeller generally adopts circular arc blade, and the rear direction impeller, the large fan adopts the airfoil blade, and the wind turbine of the coal fired boiler with low dust removal efficiency can adopt the circular arc type or the flat plate type blade. The centrifugal fan with flat blade is more.
(a) flat blade; (b) arc narrow blade; (c) arc blade; (d) wing blade; (E) flat curve back to blade
Compression impeller
Working round. The only component of the air flow in a centrifugal compressor. The most important parts on the rotor. Generally by the wheel, wheel cover and blade and other parts of the composition. Under the action of the impeller blades, the rotating speed of the leaf rotation, the gas is affected by the centrifugal force of the rotation, as well as in the impeller of the diffuser flow, so that it can be improved through the pressure of the impeller.
Requirements for impeller
(1) can be given a larger energy; (2) gas flows through the impeller loss should be small, namely the gas flows through the impeller efficiency to be high; (3) gas outflow impeller parameters when appropriate, the gas flowing behind the fixing element flow loss is smaller; (4) type of impeller can make or overall performance curves of the stable operating region and the efficiency range is wide. Normally divided into closed, semi open and open type impeller.
The impeller is composed of a wheel hub and a blade in a wind turbine. The wind passes through the impeller, drives the impeller to rotate, which drives the generator to rotate, and the wind energy is converted into electric energy. At this time, the rotating impeller with large enough on the windward side, to extract enough energy from the wind; at the same time, when the wind speed is too large, can automatically adjust the blade windward angle to avoid due to the stress and mechanical damage.
Impeller material
Cast iron, bronze, stainless steel, manganese bronze, Monel alloy, INCONEL, and non metal materials.
Non metallic materials
PPS plastic, phenolic resin, etc..
Impeller
Boat Impeller,Centrifugal Impeller,Marine Impeller,Water Pump Impeller
Unisite Group Ltd. , http://www.unisitemarine.com