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Crankshaft grinding with JUNKER grinding machines

The crankshaft is the heart of any engine. By means of connecting rods, the crankshaft converts the oscillating, linear movement of the pistons into rotational movements, which then drive the engine of the car or other vehicle.

Crankshaft applications

The crankshaft is used everywhere that energy and power are transformed into rotational movements. It has a very wide variety of applications, ranging from chainsaws to automotive engines, all the way up to diesel generators in marine engines. Typical areas of application include:

  • Chainsaws
  • Compressors / chillers
  • Power generators
  • (Gas) lawnmowers
  • Racecars
  • Aircraft
  • Rail vehicles
  • Motor vehicles such as motorcycles, cars and trucks
  • Marine enginee

Structure and types of crankshafts

A crankshaft is made up of the following components:

  • Main bearings: Centric diameters that define the rotational axis of the crankshaft.
  • Pin bearings: Receive the connecting rods, which turn the energy into rotational movements.
  • Crank webs: Connect the main bearings to the pin bearings.

Crankshafts can be forged or cast. Forged crankshafts are produced using a complicated forging method, and cast crankshafts are made by pouring molten metal into a mould. Crankshafts are also categorized according to the number of cylinders they have – anywhere from 1 to 12 and sometimes even 14 or 18. Crankshafts can range in size from just a few centimeters long (for small engines) to up to 15 or even 16 meters long (mostly for use in marine diesel engines.)

Structure and types of crankshafts
Crankshaft grinding using the pendulum grinding method

Crankshaft grinding using the pendulum grinding method

JUNKER’s pendulum grinding method is a versatile machine concept for grinding crankshafts of all types. The JUCRANK machines use the pendulum grinding method to grind main bearings (cylindrical, concave, crowned,) pin bearings (cylindrical, concave, crowned) and thrust bearings in one or multiple clamping set-ups. Hardened radii can also be ground. Using straight, narrow grinding wheels allows for main and pin bearings of different widths to be ground with the same wheel. The grinding wheel can also be swiveled, allowing each bearing to be individually corrected for cylindricity.

To the JUCRANK machine

 

Advantages of the JUNKER grinding method:

  • Taper compensation / cylindricity compensation for each individual bearing
  • Crowning can be freely selected
  • Process order can be freely selected
  • Longer grinding wheel service lives
  • Rough and finish grinding can be done in a single operation

Crankshafts for motorcycles

Crankshafts for motorcycles Crankshafts for motorcycles
Crankshafts for cars Crankshafts for cars Crankshafts for cars Crankshafts for cars

Crankshafts for cars

Crankshafts for trucks

Crankshafts for trucks Crankshafts for trucks
Crankshafts for large engines (i.e. marine diesel engines)

Crankshafts for large engines (i.e. marine diesel engines)

Address:

Erwin Junker Maschinenfabrik GmbH
Headquarters
Junkerstraße 2
77787 Nordrach
Germany