Correction Method for Crankshaft Bending of Diesel Generator

The crankshaft of the diesel generator is prone to bending during the use of the unit. Once bending occurs, it must be aligned and corrected to ensure the normal operation of the diesel generator. Today, Starlight Power Generation Equipment will introduce the correction method for crankshaft bending of diesel generator, hoping to help you:

1. Cold pressure correction

It is generally carried out on a press, as shown in Fig. 3-76. During calibration, first place the crankshaft of the diesel generator on the V-shaped block of the working plate of the press, and place copper or lead sheets between the press rod and the crankshaft to avoid damaging the contact surface between the crankshaft and the press rod. The direction of the pressure action should be opposite to the bending direction of the crankshaft. The pressure should be gradually increased by sections. After calibration, the crankshaft will often have "elastic deformation" and "aftereffect", Therefore, the reverse bending amount during correction is generally larger than the actual bending amount. For example, when the bending deformation of forged medium carbon steel crankshaft is about 0.10 mm, the bending degree of press calibration is about 3~4 mm (i.e. 30~40 times of the original bending degree), which can be corrected within 1~2 minutes; For the same bent nodular cast iron crankshaft, the press calibration is about 10~15 times of the original bending, which can be basically corrected.

It must be pointed out that when the bending of the diesel generator crankshaft is large, it should be corrected several times to prevent the crankshaft from breaking due to excessive bending, especially the crankshaft made of ductile iron. After correction, heat it to 180~220 ℃ and keep it for 5~6h to prevent elastic deformation and aftereffect.

During operation, put a dial indicator on the other side of the pressed journal to observe the reverse bending during correction. The corrected crankshaft is allowed to have slight reverse bending. The diesel generator crankshaft corrected by cold pressing shall also be inspected after being slightly knocked with a hammer at the crankshaft arm to reduce the stress caused by cold pressing.

2. Surface knock correction

The crankshaft of diesel generator with small bending can be corrected by "surface knocking" method. Knock along the left and right sides of the crankshaft arm with a ball hammer or air hammer according to the direction and extent of crankshaft bending.

3. On site correction

Place the cylinder block upside down on the working platform to make it straight. Install the old bearings (pads) on the front and rear bearing seats, and remove the middle bearing. Add a little lubricating oil on the bearing, then put the crankshaft of the diesel generator on it, install a dial indicator on the edge of the cylinder block, gently rotate the crankshaft by hand, measure the maximum bending position on the intermediate journal, mark it with chalk, pad the bearing cover gasket with soft aluminum or other soft objects, clamp the journal, slowly tighten the crankshaft bearing cover bolts, wait about 1h to loosen the bolts, and use the dial indicator to test whether it is corrected, If the allowable standard is not met, continue to re calibrate until the requirements are met.

The above three methods are the correction methods for bending of the crankshaft of the diesel generator introduced by Starlight Power Generation Equipment. When using the diesel generator, if you encounter bending of the crankshaft, you can refer to the above three methods for correction.

As a professional diesel generator manufacturer, we always insist on using first-class talents to build a first-class enterprise, create first-class products, create first-class services, and strive to build a first-class domestic enterprise. If you would like to get more information welcome to contact us via sales@dieselgeneratortech.com.