Crankpin Machining & Grinding

Crankpin Machining and Repairs

For over 20 years, In-Situ Machining Solutions (UK) Ltd have been world leaders in on-site Crankpin machining and Crankshaft repairs.

We specialise in offering an expert on site machining service undertaken by highly trained and motivated teams of engineering specialists. In-Situ can support clients during planned maintenance or emergency breakdown situations relating to refurbishing crankshaft machinery, crankpins, and main bearing Journal repair.

Crankpin Machining & Grinding

We can conduct these on land, onboard seagoing vessels, and off-shore globally. 4-Stroke Engines, 2-Stroke Engines and Compressor Shafts are all areas in which In-Situ are world leaders and offer unrivalled in situ crankshaft repair and crankshaft machinery repair. By applying our vast experience gained through years of innovation, investment, R&D and field trails, We can confidently undertake the most complex in situ crankshaft machining projects in the shortest time possible.

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 standard, 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.

Dependant upon 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 whilst the second method is to grind the crankpin journal diameter with a specially manufactured grinding machine. Both methods provide extremely accurate results to allow for the finishing process to commence.

Superfinishing

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

Polishing

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

Supplementary Services

Heat Treatment / Crankpin Annealing

In cases of severe failure, crankshafts can experience heat induced hardness due to the extreme temperatures in which they are exposed to and the rapid cooling process post failure. This generates hard areas within the crankpin journal that are often in excess of 650HB and can also introduce a heat induced runout within the shaft. The run out and hard patches are areas of extreme stress and often sit well outside of the OEM specification. Introducing a crankpin annealing process will heat, soak and cool the crankpin in a tightly controlled manner over a period of time using a resistance heat treatment process that utilises ceramic blankets acting as a controlled stress relief process. The cycle time varies dependent upon size of the journal and severity of the failure. The process used in a combination with machining can reduce heat-induced hardness and run out within the Journal that sit above OEM specification.

Peen Straightening

If a crankshaft is experiencing run out due to excessive heat after a failure, a combination of machining, annealing and peen straightening are used as a stress relive process to relieve the run out.

Peen straightening is a specialist technique used as stress relief to aid 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 resulting in a reduction in 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.