The largest lathe in the world

We have provided major base industries such as automobile industry, aircraft and shipbuilding industries, construction industry, and iron steel industry with the lineups of large machines and special machines. We also have provided many large lathes. Among them, we introduce the largest lathe in the world.

Developed technology of the largest lathe in the world

We have developed the largest rotor lathe SLR340×20M that can take in and machine 400 ton of workpice that is the largest in the world.

How much the weight of 400 ton
 Jumbo jet aircraft (B747)

It is the same weight as one jumbo jet aircraft (maximum mass on taking off)
(Maximum mass on taking off is 420 ton in B747-400.)

Features of SLR series
overall view of SLR340×20

Our large lathe SLR series are characterized by separate bed with four slideways, head stock with integral structure, and large spindle bearing. We design and make the lathe that ensures highly precise machining though it is the large machine.

Main specifications of SLR340×20M
Max. mass of workpieces 400t(881,800lb)
Max. turning diameter 3,400mm(133.9”)
Max. recommended workpiece length 20,000mm(787.4”)
Spindle speed range 0.4-80min-1
Max. turning spindle torque 371,000N-m
Spindle power 500kW
Design development
head stockthat bear analysis model

We installed FEM (Finite Element Method) structural analysis tool 30 years ago and have designed and developed the machine not depending on one’s hunch but having numerical proof.
In addition, we improve precision of FEM structural analysis by doing various kinds of tests to completed machines and accumulate its data.

In development of this machine, spindle and head stockthat bear 400 ton of weight are designed based on FEM structural analysis. Especially, head stock has rigid structure that is necessary for ensuring machining precision. This structure was born from the arrangement of rib based on stress and displacement analysis.

Parts machining
Head stock machining

Large parts are machined by bridged-type five-face machining system(HF8M) and measured by 3-D coordinate measuring machine (MM3500) in order to ensure unit precision.

However, we found that simple machining couldn’t ensure precision on actual use position because the head stock of this machine had different position between actual use and machining, and the machine had a few 10μm of displacement that is caused by its weight. Therefore, we analyze displacement, compensate it according to the result, and machine so that necessary precision is ensured.

Large five-face machining system
Size of working surface:4,000×13,000mm
Distance from table top to spindle end:4,885mm
Max. table load capacity:120,000kg
3-D coordinate measuring machine
Travel of each axes (X×Y×Z):12,000×3,500×2,000mm
assembly in the factory

Our factory keeps constant temperature and ensures precision management and acquiring precision by doing from parts machining to assembly in the factory.

Therefore, large bearing that is sensitive to temperature change can be assembled precisely.

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