Gear technology and automation systems
LGG 300 - 500 / 700 M

The allrounder.

Highlights

    Flexibility
    Technological diversity
    Powerful
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    Machine design

    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.

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    LGG 700 M

    Liebherr also offers a manual generating and profile grinding machine for small batch sizes and outstanding flexibility.

    • Generating grinding max. workpiece diameter (mm): 500
    • Profile grinding max. workpiece diameter (mm): 700

    The machine is exclusively loaded manually. A handling device (crane) mounted on the machine roof and an NC-swiveling tailstock make manual loading much more simple.

    External and internal grinding heads

    Process-optimized external grinding heads and internal grinding arms are available for the LGG. Balancing systems inside the spindle are used in both external grinding heads (GH 320 and GH 240 CB). On the GH 320 CB, the balancing system is integrated in the arbor.

    High drive power and speeds are major advantages – for example, when using new grinding materials. The modern tool holding makes it possible to replace the grinding arbor quickly and easily.

    Small grinding tool diameters are available for collision-critical workpieces and for special tooth corrections.

    With the GH 320 CB grinding head, it is now also possible to efficiently grind optimal-quality workpieces up to module 14 mm.

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    GH 240 / 200 CB

    Technical data GH 240 CB

    Speed (rpm): 12,000
    Grinding spindle drive power (kW): 28.5
    Max. grindable module generating grinding (mm): 7
    Max. grindable module profile grinding (mm): 14
    Electro-plated CBN tools: Yes
    Dimensions of grinding worm: (DxLxW): 240x200x76.2

    Technical data GH 200 CB

    Speed (rpm): 17,000
    Grinding spindle drive power (kW): 28.5
    Max. grindable module generating grinding (mm): 5
    Max. grindable module profile grinding (mm): 14
    Electro-plated CBN tools: Yes
    Dimensions of grinding worm: (DxLxW): 240x200x40 (76.2)
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    GH 320

    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

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    GH 320 CB

    Drive power (kW): 28.5
    Speed (rpm): 10,000
    Max. cutting speed (m/s): 80
    Max. grindable module generating grinding (mm): 14
    Max. grindable module profile grinding (mm): 14
    Max. shift distance (mm): 350
    Dimensions of grinding worm (DxLxW) (mm): 320x250x110
    Feature: Internal grinding arms are available for all grinding heads.

    Can be used with LGG 300, LGG 380, LGG 500 and LGG 700 M

    Fast and easy changeover

    The adaptable internal grinding arms can be mounted quickly and easily on the external grinding head and are driven using the main drive. Other grinding heads can be provided on request.

    In only 30minutes from external to internal grinding

    Video

    Generating grinding planetary gears, module 14, on the LGG 500 generating and profile grinding machine

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    On-board inspection: Gear check in the machine

    All grinding heads can be equipped with an optional swivel-in probe for gear checking.

    Gear measurement

    • Profile and lead
    • Concentricity, single and cumulative pitch
    • Twist check
    • Measuring system for grinding stock removal
    • Rolling measurement
    • Determining dimension measurement
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    Mobile or stationary meshing sensor

    Technology

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    Prepared for the future

    Type of gears

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

    Gear modification

    • Profile and lead modification
    • Free flank form
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    Cycloidal gears

    For cycloidal drives, certain requirements must be met, such as dimensional precision, a high-quality surface, an excellent profile and pitch as well as rollers that fit perfectly to the inner ring. Liebherr has developed something new for cycloidal gears: Now, cam disks with an external gear can be produced via generating grinding using not only single but also perfectly adapted double clamping. Depending on the individual batch-size requirements, which means that besides conventional profile grinding, an additional grinding method for cam disks is now available to users.

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    Generating grinding asymmetric gears

    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
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    Topological modifications

    • TF twist-free grinding
    • DFT deviation-free topological grinding
    • GER generated triangle-shaped end relief

    Modifications for noise reduction

    • SSG noise-reduction shift strategy
    • NEO noise excitation-optimized modifications

    Generating grinding with small tools

    Finishing grinding or polishing

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    Why modified and/or super-finished leads?

    Motivation:

    • Improved wear behavior
    • Reduction of friction losses
    • Increased flank and tooth root strength
    • Increased efficiency
    • Longer service life (gear and gearbox)
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    Our solution: Finish grinding or polishing

    Lower surface roughness can be achieved with finish grinding or polishing. This increases the power density and gear efficiency.

    Generating or profile grinding with dressing-free CBN

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    CBN generating grinding

    • Short machining times (two-cut strategy)
    • No dressing required
    • Very low risk of grinding burn (short contact time, good thermal conductivity of CBN and steel basic body)
    • Universal tool design
    • Very long tool life
    • Robust process with high process stability
    • Module range 1.0 - 5.0mm
    • External gears with a high toothed length
    • Large batches, perfect for three-shift operation
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    CBN profile grinding

    • 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

    Integrated centrifugal device

    Automation

    Easy to operate

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    The new optimized control panel LHStation & LHMobile

    With the control panel, Liebherr intelligently divides the programming and operation of the machine between two system parts: The large, fixed monitor unit LHStation for data input and process monitoring and the standardized, mobile handheld terminal LHMobile with context-sensitive user guidance during setup. Both units have a multi-touch surface as well as tactile elements for optimum operating speed and operating safety.

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    Technical data

    VariantsLGG 300LGG 380LGG 500LGG 700 M

    LGG 300 - 500 / 700 M