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What should I pay attention to when disassembling diesel generator sets for maintenance?

June 29, 2022
We introduced you to the diesel generator set repair before disassembly to do the preparatory work, some users may think that the disassembly of the generator set is a very simple matter, but if you do not pay attention to the disassembly of parts, do not pay attention to the connection between the parts, will likely cause damage to the machine or other accidents, affecting the normal conduct of the repair work. Therefore, in the diesel generator set for disassembly and maintenance, but also pay special attention to the following issues.
1, must be completely cooled in the case of the machine. Otherwise, due to the impact of thermal stress, the cylinder block, cylinder head and other parts of the permanent deformation, resulting in a variety of internal combustion engine performance.
2, in the disassembly of the cylinder head, connecting rod bearing cover, main bearing cover and other parts, the bolt or nut release, must be in a certain order symmetrical evenly in 2 ~ 3 times disassembly. Never allow loose side and then loose the other side of the nut or bolt, otherwise, due to the uneven force on the parts and parts deformation, some even produce cracks and damage.
3, carefully do the check mark work. Timing gear, piston, connecting rod, shaft, valve and the relevant adjustment gaskets and other parts, there are marks down, no marks should be made on the marks. Marking should be played in the easy to see the non-working surface, do not damage the assembly reference surface, in order to try to maintain the original machine assembly relationship, some parts, such as internal combustion engines and generators on the joints of the wires, etc., stay with paint, scoring and hanging signs and other methods to mark.
4, disassembly can not be pounded, the correct use of various tools, especially special tools. For example, when dismantling the piston ring point try to use the piston ring loading pliers, dismantling the spark plug application spark plug sleeve, and the force can not be too violent. Otherwise, it is easy to make their hands injured, and easy to damage the spark plug.
In the disassembly of threaded connections, you must correctly use a variety of wrenches and spinning tools, often due to incorrect use of wrenches and spinning tools will be damaged nuts and bolts. For example
(a) When the opening width of the wrench is larger than that of the nut, the angles of the nut are easily rounded.
the thickness of the head of the spinner and the head of the screw.
notch does not match, easy to make the edge of the notch broken.
when using wrenches and spinners, the tool is properly placed in the nut or groove at the end and then starts to rotate, which will also produce the above-mentioned problems.
the use of an excessively long stiffener bar can cause the screw to break due to rusting or when the screw is screwed too tightly for easy removal
Due to the screw or nut does not understand the positive and negative buckle or disassembly is not skilled, the direction screwed backwards will also cause the screw or nut broken.
Precautions for disassembly and installation of alternator synchronous generator
Before disassembling the synchronous generator, the state of the winding, insulation resistance, the state of the bearing, commutator and slip ring, brush and brush grip and rotor and stator fit and so on should be checked and recorded, so as to have an understanding of the original fault of the motor to be serviced, determine the overhaul plan and material preparation to ensure that the overhaul work is carried out properly.
1, when disassembling the connection joints, should pay attention to the line head marking, such as marking missing or blurred, should be re-marked. When reassembled according to the original position of the wiring diagram reconnected, not connected to the wrong.
2, the unloaded parts should be properly preserved, not at random, so as not to lose, parts should be placed carefully and gently to avoid deformation or damage caused by impact.
3, in the replacement of the rotary rectifier components, pay attention to the rectifier component conduction direction should be consistent with the original component direction, using a multimeter to measure its forward and reverse resistance, can determine whether the silicon rectifier components are damaged. Rectifier element forward (on direction) resistance should be very small, measured with a multimeter should be less than a few thousand ohms, while the reverse direction resistance should be large, generally greater than 10kΩ.
4, such as the replacement of the generator excitation winding, the connector should pay attention to the polarity of the magnetic pole. Magnetic pole coils should be a positive and negative sequence in series, the permanent magnet on the stator of the exciter, facing the rotor end of the polarity of N, the magnetic poles on both sides of the magnet for S, the end of the main generator excitation winding should still be played on the wire hoop. The diameter and number of turns of the wire should be the same as the original. After the insulation treatment, the generator rotor should be corrected on the dynamic balancing machine. The method of correcting dynamic balance is: on the fan of the generator and the non-dragging end of the balance ring on the weight.
5, disassemble the bearing cover and bearing, pay attention to the removed parts with clean paper properly covered to avoid dust flying into, such as dust intrusion bearing grease, bearing grease should be replaced in its entirety.
6、When reassembling the end cover and bearing cover, a little oil should be added to the end cover stop and fastening bolts to make it convenient to disassemble again. End cover or bearing bolts should be crossed one by one, not tighten one and then tighten the rest.
7, the generator assembly is completed, slowly rotate the rotor by hand or other tools should rotate flexibly, no rubbing phenomenon.