Crankpin Machining & Grinding

Crankpin Machining and Repairs

With over 20 years of experience, our highly trained engineering teams offer expert onsite machining services. We specialise in refurbishing crankshaft machinery, crankpins, and main bearing journals during planned maintenance or emergency breakdown situations.

Crankpin Machining & Grinding

We conduct crankpin machining and grinding on land, onboard seagoing vessels, and globally off-shore. Our expertise extends to 4-stroke engines, 2-stroke engines, and compressor shafts, making us unrivalled in in-situ crankshaft repair and machinery repair. Utilising our extensive experience, innovation, and field trials, we confidently undertake complex in-situ crankshaft machining projects efficiently.

Further Information On Main Bearing Grinding

Crankpin Machining Grinding

Crankpin Recovery Process

Failure Assessment & Inspection

The process includes multiple services in which the Crankpin Journal’s condition is assessed. This allows a plan to be put in place for Crankpin machining operations. The program may include all or some of the following services:

Exploratory Grinding

Run Out Checks

Crack Detection

Hardness Testing

Crankpin Calibration

Flatness Checks

Machining & Grinding

A purpose-built orbital turning machine is utilised to machine the Crankpin diameter to remove any damage or wear and restore OEM-specified tolerances to the Journal diameter, radii, and oil holes.
Depending on the engine model, crankshaft type and nature of the repair, the material removal process can take multiple forms.
One method is machining the crankpin journal with a single-point tool attachment, while the second is grinding the crankpin journal diameter with a specially manufactured grinding machine. Both methods provide extremely accurate results, allowing the finishing process to commence.

Superfinishing

Superfinishing is a process in which a specialist superfinishing machine holding a carborundum stone oscillates from side to side over 6000 times a minute whilst rotating around the journal. After the machining process, the process is used to flatten off the surface, improve the surface finish of the Crankpin Journal and prepare the diameter for the final polishing operation.

Polishing

An in-house specialist designed and built a mechanical polishing system that ensures flatness allows close control of geometric tolerances, and produces a surface finish within the OEM specification.

Supplementary Services

Heat Treatment / Crankpin Annealing

Crankshafts can develop excessive hardness and runout due to extreme temperatures and rapid cooling after failure. These hard areas, often over 650HB, and run out exceed OEM specifications, causing significant stress. To address this, crankpin annealing utilises controlled heat treatment with ceramic blankets. The cycle time depends on journal size and failure severity. Combining annealing with machining can reduce excessive hardness and runout in the journal, bringing it within OEM specifications.

Peen Straightening

Suppose a crankshaft is experiencing runout due to excessive heat after a failure. In that case, a combination of machining, annealing and peen straightening is used as a stress relief process to relieve the runout.

Peen straightening is a specialist technique used as stress relief to aid in the reduction of any runout within the shaft.

The process uses a peen hammer to strike the Journal in certain areas to release stresses from the affected area, reducing bend/runout.

Relatable Industries

We at In-Situ, are proud of our services, supporting a broad range of industries and providing vital on-site machining needs for our clients 24/7. Below is a range of the various sectors of industry that our services are utilised.