LGG 300 - 500 / 700 M

Generating grinding, profile grinding and internal grinding in one machine

Flexibility is essential for job shops and small lot sizes. The new LGG series has been specially designed for universal use, as well as for large series production. It combines three technologies: Generating grinding, profile grinding and internal grinding. This technological diversity provides the universal user with maximum benefit and a secure investment for the future.

This machine can be configured for individual applications, so it is perfect for use in the production of large batches. This is where external automation systems such as a plastic chain conveyor or a robot system are used.

The LGG is the most powerful generating and profile grinding machine of its class on the market. With the new GH 320 CB grinding head, it is now also possible to efficiently grind superior quality workpieces up to module 14. The LGG 700 M is a manual gear grinding machine that can grind workpieces up to 500 mm (generating) and up to 700 mm for profile grinding.

_{X1 - radial movement of column slide | V1 - tangential movement of tool | Z1 - axial travel of grinding head | B1 - rotary movement of tool | C2 - rotary movement of workpiece | A1 - swivel movement of tool | Z4 - vertical travel of steady column | C3 - rotary movement of ringloader}

Speed (rpm): 7000
Grinding spindle drive power (kW): 28.5
Max. grindable module generating grinding (mm): 9
Max. grindable module profile grinding (mm): 14
Dimensions of grinding worm (DxLxW) (mm): 275(320)x160x160

Our software continuously monitors the entire grinding and dressing process in real time. You no longer need to worry about human errors or undetected anomalies. The software immediately recognizes when a parameter exceeds the set limits.

The software uses a smart learning process to determine the optimal limit values for your processes. Using the data recorded while manufacturing the training workpieces and by detailed measurements in the quality lab, the software ensures that the limits are precisely tailored to your specific workpiece and process requirements.

If a workpiece exceeds the predefined limits, it is colorcoded in the software as an immediate visual indication of a limit violation. You can also respond to these detected anomalies with preconfigured machine actions.

Type of gears

• Asymmetric profile
• Beveloid gears
• Double helical gears
• Cycloidal gears

Gear modification

• Profile and lead modification
• Free flank form

Asymmetric gears compensate for unequally distributed loads.

The advantages of asymmetric gears are obvious:

• Reduced tooth root clamping forces and Hertzian flank stresses
• Improved specific sliding
• Increased surface durability and tooth root strength
• Increased power density (load capacity in relation to gear size)
• Longer service life
• Increased efficiency
• Reduced noise and vibration excitation
• Increased operational reliability

Machine technology:

• Centering of the dresser/grinding worm
• Centering of the asymmetric grinding worm/workpiece
• Initial profiling and tracking of the asymmetric profile at every dressing cycle
• Precise control technology for dynamic tooth flank contact sequences

Technology:

• Coordination of dressing and grinding parameters
• Selection of appropriate grinding worm specifications

Motivation:

• Improved wear behavior
• Reduction of friction losses
• Increased flank and tooth root strength
• Increased efficiency
• Longer service life (gear and gearbox)

DIP is a versatile generating grinding method specially developed by Liebherr that uses dressable grinding worms. It allows profile modification on the workpiece when using profile rolls in the dressing process. In particular, profile angle modifications, crowning, as well as tip and root reliefs can be precisely specified and ground. It offers the advantage that using profile rolls makes the dressing process many times faster, and the surface of the worm is the same as for typical series production.

The main advantage of asymmetric gears is the reduction of contact stress on the drive flanks. This increases power density. Moreover, targeted tuning of the asymmetric profiles can significantly reduce vibrations, which in turn leads to less noise from the gearbox. Liebherr’s Modified Centering ensures the same stock is ground despite the asymmetry on both tooth flanks, making the process as efficient as with normal gears.

• Very high profile quality
• Pressure angle can be corrected by CNC (A, V and X axes)
• Long tool life
• Grinding of non-generating profiles and complex geometries
• Module range 1.0 - 8.0mm
• External and internal gears
• Collision-critical gears (discs Ø < 30mm)
• Small and medium-sized batches