Reaming Technical Requirements For Piston Pin And Connecting Rod Bushing

When the piston pin of diesel generator set is repaired and replaced, the connecting rod bushing shall be selected. If the bushing is worn too thin, the new bushing shall be replaced. The fit between the bushing and the small inner diameter of the connecting rod should have an interference of 0.04~0.10 mm. How should the piston pin and connecting rod bushing be hinged? Next, let's take a look at the hinge fitting of piston pin and connecting rod bushing with Jiangsu Starlight Power.

(1) Technical requirements.

① With clearance gasoline engine, there is a slight clearance of 0.003~0.010mm at normal temperature. The diesel engine has a clearance of 0.02~0.12mm at normal temperature.

② The contact area shall not be less than 75%. The hazard of too large or too small clearance and too small contact area is the same as that of too large or too small clearance between piston pin and pin seat hole and too small contact area. The correct fit of piston pin and connecting rod bushing is achieved by reaming.

(2) Reaming of connecting rod bushing Reaming procedure of connecting rod bushing is similar to that of piston pin seat hole.

① Select the reamer: Select the reamer according to the actual size of the piston pin, and clamp the reamer into the vice perpendicular to the jaw plane.

② Adjust the reamer: Put the small end of the connecting rod into the reamer, hold the large end of the connecting rod with one hand, and press the small end with the other hand. The reaming amount of the first cutter is 3~5mm when the blade can expose the upper plane of the bushing. The adjustment amount of the reamer should be 60 °~90 ° by rotating the nut. If the amount of reaming is too large or too small, the connecting rod will swing in the reaming process and hinge out the calibration sill or bell mouth.

③ Reaming: When reaming, hold the big end of the connecting rod with one hand, and turn it with even force, hold the small end with the other hand, and apply downward pressure for reaming. During reaming, the connecting rod shall be kept at right angles to the reamer to avoid reaming deviation. After adjusting the knife once to the bottom, turn the connecting rod upside down and hinge it again to prevent it from becoming tapered. When the lower plane of the bushing is flush with the lower direction of the blade, the small end of the connecting rod should be pressed down to make the bushing come out from the lower part of the reamer, so as to avoid arris.

④ Trial fitting: During reaming, the piston pin shall be used frequently for trial fitting to prevent reaming. When the pin can be pushed into 1/3~2/3 of the bushing with the force of the palm, the reaming shall be stopped. At this time, press the pin into the bushing or use a wooden hammer to drive it into the bushing (prevent the pin from tilting when driving), hold it on the vise and turn the connecting rod back and forth, and then press out the pin to check the contact condition of the bushing.

Scraping shall be carried out with a scraper according to the contact surface and tightness of the piston pin and connecting rod bushing. After scraping, it shall meet the requirements in the instructions of each machine.

⑤ Scraping: According to the contact surface and tightness of the piston pin and connecting rod bushing, use a scraper to scrape. After scraping, it shall meet the requirements in the instructions of each machine.

For diesel generator sets, the general inspection method is to coat the piston pin with oil, push the piston pin into the connecting rod bushing with the power of the palm of the hand, and there is no sense of clearance, then the tightness is considered as appropriate. For gasoline engines, the general inspection method is to coat the piston pin with oil, push the piston pin into the connecting rod bushing with the force of your thumb, and there is no feeling of clearance, then the tightness is considered as appropriate. If the contact area is more than 75%, and the contact points are evenly distributed, the contact surface is considered to meet the requirements.

Jiangsu Starlight Electricity Equipments Co.,Ltd. has a young and professional technical backbone team, with an average working age of more than 10 years in the generator unit industry. There are 64 sales and service departments throughout the country to provide users with a one-stop service of machine room design, equipment supply, commissioning and maintenance at any time. No matter when and where, a well-trained service team will provide you with comprehensive and considerate protection. For more details, please contact us with sales@dieselgeneratortech.com.