Preparation of diesel generators prior to disassembly

1. Preparation before disassembly
(1) understand the technical status of the unit

When repairing or maintaining, the maintenance personnel should have a comprehensive understanding of the malfunction, technical status and use of the diesel generator set. If the voltage swing of diesel generator sets is too large, it should be basically determined which device or part of the control panel fails and then tested or disassembled.

(2) complete equipment maintenance data preparation

When repairing the diesel generator set, the operating instructions, technical data and requirements for repairing the diesel generator set of this model should be made clear. When it is difficult to find the technical data of individual diesel generator sets, the relative positions of various parts should be recorded in the process of disassembly so as to be used in assembly.

Before disassembly, a certain maintenance space should be prepared to prevent dust or rain from entering the diesel generator unit.

(3) complete preparation of common tools and special tools

Different types of diesel generator set used special tools may be different, but the commonly used tools are the same, if the wrench, plum wrench, pliers, socket wrench, adjustable wrench, torque wrench, hammer, wooden hammer, hacksaw blade, etc.

Special tools for disassembling diesel generators include: special pullers for disassembling valve ducts, gears and rolling bearings, special pullers for disassembling cylinder sleeves, etc.

(4) hoisting tools and all necessary equipment should be ready

The removal of the crankshaft of diesel generator set and the hoisting of the body all use block, cable rope, jack, lifting frame and lever

And so on.

The main equipment used in the disassembly is oil barrel, square dish for washing parts, oil washing, diesel oil, brush, sandpaper and recording of cylinder parts

Labels and labor insurance products, etc.

Principles and requirements for disassembling diesel generators

(1) master the structure and principle of the unit

Diesel generators operate in much the same way, but have many different models and structures. In order to prevent the damage to the unit while disassembling parts or change to other parts of normal fit clearance, remove the former must understand the structure of the relationship between various parts, and to see the diesel generator set random carry instruction and other technical information related to the repair.

(2) repair and assembly should be taken into account when disassembling

Removing diesel generating sets, without technical data and specifications, and with a series of maintenance data are lacking, also should be in before disassembly will all sorts of data and remove all kinds of torque in the process of the recorded, such as fuel injection advance Angle, valve clearance, unscrew the connecting rod bolt torque, remove the cylinder head screw torque, such as the relative position of the parts before disassembly, used for assembly and troubleshooting.

(3) master the general method of disassembly

There are certain technical requirements for disassembly of all parts of the unit. Generally, external parts are removed first and internal parts are removed later. Remove the accessory parts first, then the main parts; Remove the whole part first, then decompose the whole part. 
(4) correct use of disassembly tools

Removing unit parts, can use the ring spanner and box spanner remove as far as possible need not stay pull in and live wrench, the latter two wrench in the use of easy sliding, can damage the original nut edges, and ring spanner and box spanner parts force equilibrium, it is not easy to cause damage to the parts. When tightening and removing screws or nuts, the torque should be appropriate and the extension rod should not be used. Force should be even when removing parts to prevent damage to parts and tools caused by excessive force.

(5) master disassembly skills and part straightening requirements

The scope of the disassembly unit shall not be arbitrarily expanded. It shall be determined according to the fault phenomenon and the repair content and items, and it shall not be disassembled as much as possible without disassembly. The removed parts should be placed in an orderly way and not put together in disorder. The parts that cannot be repaired for a long time should be treated with anti-rust treatment, and the removed precision parts should be put in pairs. During the whole process of disassembly, the parts should be prevented from deforming and personal safety should also be paid attention to.

3. Disassembly skills of components of diesel generators

(1) skills of removing double-headed bolts

Diesel generator unit cylinder head fixing bolts, main bearing bolts, cylinder head housing fixing bolts and inlet and outlet pipe fixing bolts are double-head bolts. The size and specifications of these bolts are generally different at both ends, even with one end of fine wire and the other end of thick wire. To this kind of bolt, generally do not remove, if must be removed, the double nut disassembly method available: on the one end of the bolt thread screw two nut and relatively tight, as shown in figure 9-1, then the bolt with plum blossom or socket wrench screw out, this method is simple, is widely used.

Note: double-head bolts should not be removed with pipe tongs to prevent damage to the bolt surface.

(2) disassembly technique of bolt with broken head

Some tips for breaking bolts are as follows:

When a portion of the stud bolt is still outside the threaded hole, a groove can be sawed at the top of the bolt and then spun out with a screwdriver. It can also be welded on the top of the bolt, and twisted out by rotating the steel bar.

In case of a screw hole, a smaller diameter hole can be drilled at the top of the bolt, the reverse screw thread can be tapped in the hole, and then a screw can be spun to screw out the bolt.

Bolts that cannot be unscrewed can be drilled with a drill bit smaller than the diameter of the screw hole, o.5 ~ LMM, to drill off the screw column, and then tapped with a tap of the same screw moment as the original bolt, which can usually be spun out. If the threaded hole is damaged by accident during drilling, the increased thread should be used with bolts.

(3) removal techniques of rusty nuts

In the process of disassembling diesel generator sets, rusting nuts are often encountered, which can be tightened first and loosened later

It can also be removed by heating the nut evenly with a spray lamp or by dripping gasoline between the nut and the bolt.

(4) the disassembly technique of overfill fitting

Surplus parts are usually removed with special tools. For example, remove piston pin by heating method, disassemble valve pipe by means of fittings, etc.

(5) the removed parts shall be marked and labeled

The removed parts, such as the injector, connecting rod, connecting rod bolts, etc., should be labeled with the number of cylinders. The removed nuts, gaskets and bolts should be placed in pairs and sorted.