Cylinder Liner Technical Requirements of Diesel Generator Set

Basic structural principle of diesel generator set cylinder liner

The working condition of the diesel generator set cylinder liner can be said to be “the dirtiest and most tiring”, which plays the role of purifying and isolating pollution. Its working condition directly affects the normal operation of the diesel generator set. If it is used improperly, it will cause serious wear and tear. Damages such as holding cylinders and cavities, and even serious accidents. The following will give you a brief introduction to the structural principle of the diesel generator set cylinder liner.

There are two kinds of cylinder liners for 135 series diesel generator sets, namely high-phosphorus cylinder liners and phosphating cylinder sleeves. For high-speed models with speeds above 2000r/rain, in order to improve their initial running performance, phosphating cylinder liners must be used. . It can be used for two kinds of cylinder liners of basic diesel generator sets.

The structure of the cylinder liner is a typical wet cylinder liner, which is suspended and positioned by its upper shoulder. The lower shoulder plane is supported on the body, and a copper washer with a thickness of 0.25 is placed between them (Fig. 1) to ensure the sealing of the coolant. There is a section of the outer circle below the shoulder that is the positioning part of the cylinder bore of the body, that is, the upper positioning belt, and a lower positioning belt at the lower part of the cylinder sleeve, which is sealed with two O-rings between the cylinder bore of the body to achieve coolant sealing. Due to the structural size of the original sealing ring and the structure of the semi-circular sealing groove are not reasonable, our factory began to use a new sealing ring with a diameter of Φ140 in 1988, so please pay more attention. The use of a new sealing ring has changed the past. The sealing ring of Φ86 must be stretched a lot to fit into the cylinder liner sealing groove of diameter Φ154, which reduces the labor intensity of the operator and, more importantly, the new sealing ring can be stretched a lot. In the cylinder sleeve sealing groove with the diameter Φ154, the labor intensity of the operator is reduced, and more importantly, the deformation of the new sealing ring in the working state is relatively large, so that the roundness of the inner hole of the installed cylinder sleeve is greatly improved, and the sealing property is also improved.

After long-term use of the sealing ring, if it is found to be leaking, it is caused by damage to the sealing ring or hardening of the sealing ring, so it must be replaced in time. The smooth surface of the rubber sealing water ring without the parting surface should be evenly attached in the circumferential direction without distortion (Fig. 2). If improperly assembled, it will also cause deformation of the cylinder liner and water jacket leakage.

If the cylinder liner is worn to a certain extent or if the honeycomb wall is found to have a depth of more than 2 mm, it can be disassembled and replaced with a tool as shown in Figure 3. If the hole is shallow, the cylinder liner is rotated relative to the original position. 90 installation, can still continue to use.

What are the technical requirements for the diesel generator set cylinder liner?

The technical requirements for general repair of diesel generator sets are as follows:

1. Diesel generator set cylinders must be repaired or replaced if they are worn to one of the following conditions:

A. Crack in the cylinder wall

B. The scratch depth of the cylinder wall is greater than 0.25mm

C. The wear of the cylinder is greater than 0.35mm or the clearance between the skirt and the cylinder wall is greater than 0.5mm.

D. The cylinder's out-of-roundness and taper are greater than 0.15mm

2. Technical requirements for diesel generator sets or overhaul plants

A. The size of the cylinder meets the requirements on the instructions

B. The cylinder's out-of-roundness and taper are within 0.03mm

C. The internal surface roughness of the cylinder is not higher than 0.32-0.63um

D. The depth of the local dent is not more than 0.03mm

According to the measurement results, when the wear amount, out-of-roundness and taper of the diesel generator set cylinder exceed the specified values of various machines, the cylinder should be repaired to restore the normal technical requirements of the cylinder.

Diesel generator set cylinder liner installation steps

The diesel generator set cylinder liner is one of the important components of the combustion chamber. Its main function is to form a space for gas compression, combustion and expansion with the cylinder head and piston, and to guide the reciprocating motion of the piston. When the diesel engine is running, the cylinder liner also transfers a portion of the heat to the cooling water or air to ensure that the combustor assembly operates normally in a high temperature and high pressure environment. So what is the installation procedure for the generator set cylinder liner?

Step 1: Insert the cylinder liner and the copper gasket without the rubber sealing water ring into the body, press the cylinder sleeve tightly on the upper end surface, and then measure the distance from the top surface of the cylinder sleeve to the top surface of the body by the depth centimeter caliper. . This distance should be 0.04-0.15mm.

Step 2: Check whether the distance between the upper surface of the two cylinder liners that share a cylinder head protrudes from the top surface of the cylinder is within 0.04 mm. If it is exceeded, the cylinder liner should be selected.

Step 3: After installing the rubber sealing water ring as required, insert the cylinder liner and the copper washer into the body, and measure the inner diameter of the cylinder liner along the center line of the crankshaft and the center line of the vertical crankshaft in the position specified in Figure 1, respectively. The specified inner diameter is ∮135+0.04.

When overhauling the diesel generator set, check whether there are holes in the water compartment of the cylinder block. For small perforations, it can be carefully repaired and suffocated, but it can not damage and deform the mating surface, and at the same time clean the blocked water and oil passage.