GEAR CUTTING OPERATIONS

This presentation will show basically different cutting operations of gears generally, without taking into account detailed specific gear shapes and details in particular.

Due to this reason we summarize single machining sectors into a concrete overview supporting interested persons to get simplification possibilities.

Gear processing is categorized into 3 basically different types of processing:

Soft machining in the sector for Q and T steels is achieved by:

• Hobbing
• Punching and
• Shaving.

Afterwards follows hardening and tempering

This is processed by:

1.  Heating in salt bath – Quenching in salt bath

2. Heating in single and multi chamber furnaces as well as in conveyor systems – Quenching in substance-hardening oil or in warm bath hardening oil with much lower Leidenfrost.

3. Induction heating – Quenching by rinsing with polymer-based water soluble hardening fluids.

• Dionol^® Spezial HO V 1216 – Viscosity at 40 °C 19,3 mm²/s – High performance substance hardening oil, not water-soluble
• Dionol^® Spezial HWB 449 – Viscosity at 40 °C 305 mm²/s – Warm bath hardening oil, not water-soluble
• Dionol^® Spezial HWB 1559 – Viscosity at 40 °C 470 mm² – Warm bath hardening oil , not water-soluble
• Dionol^® Spezial HOW V 1485 – Viscosity at 20 °C 670 mm²/s – highly quenching, water-soluble for induction heating
• Dionol^® Spezial HOW V 1570 – Viscosity at 20 °C 320 mm²/s – lowly quenching,  water-soluble for induction heating

• Especially in the grinding sector of finishing exist very different types of operations. Not only finishing machines but also the entire technology in this process proceeds in different manners. Finally the main target is to process cost-effective. Here different grinding tools and different grinding technologies are used.

  Only a few years ago very different grinding fluids have been used to get an optimal grinding result with desired surfaces and as far as possible without any grinding burn.

  For all mentioned types of machining developed MKU-Chemie GmbH special oils, which meet the requirements as well as in soft machining as at grinding (hard machining).

  At hard machining it is known, that in many cases the possible grinding performance, wanted and strived for, cannot be achieved, by unsuitable grinding tools and unsuitable grinding oils.

  Now we should bring closer to the valued reader the single technologies of grinding:

  Gleason – Grinding technology
  Grinding is carried out with CBN-grinding tools, sintered corundum tools and corundum tools of different types.

  Reishauer – Grinding technology
  This technology is carried out by gear cutting operations mainly with grinding tools of several profiles from corundum to sintered corundum.

  Liebherr – Tooth cutting technology
  This process is carried out with metal grinding tools in form of screws, fitted with CBN.

  Kapp – Grinding technology
  This technology is carried out by special produced CBN-fitted grinding tools.

  Höfler – Grinding technology
  This is carried out by high performance tooth flank grinding with corundum or sintered corundum grinding tools

  By developing HEDG-high performance-general-purpose-grinding and tooth cutting oil Rotex^® Spezial 277 (viscosity at 40 ° C 16,7 mm²/s), the former mentioned different grinding types has been achieved an optimal performance in a more or less larger extent during a long-period cooperation  with clients of above mentioned machine manufacturers .

  On the other side we also developed a variations of the former mentioned product with a lower viscosity for all purposes as a general-purpose special oil, which is HEDG-oil Rotex^® Spezial V 1217 (viscosity at 40 ° C 10,5 mm²/s) in the same formulation as Rotex^®Spezial 277.

  Screw and thread grinding are similar process technologies and established in the gear industry .

  There are several manufacturers of gear cutting machines from which we mention only two on behalf of others

  • KLINGELNBERG
  • MIKROMAT

  In both cases Rotex^® Spezial V 1217 (viscosity at 40 ° C 10,5 mm²/s) is used. The suitable grinding tools are of corundum to sintered corundum.

  As you can see, at Rotex^® Spezial V 1217 the base oil viscosity is replaced by a lower one which has been established in certain ranges and types of production.

  Rotex^® Spezial 277 remains in use, as this oil still brings reserves for better grinding tools at known grinding parameters und in this way improves machine performance.

  In this application also the generally known AF-(anti-fogging)-additives of MKU-Chemie GmbH in use, so that both former mentioned special oils may also be supplied with AF-additives.

  After explaining grinding performances in the sector of grinding technology, a range of companies reduced their range of products for soft and hard grinding to only 1 or 2 products, where formerly 6 to 7 products were in use   This reduction resulted in an improvement of cost-effectiveness.

  In some special cases MKU-Chemie GmbH succeeded in taking positive impact in the sector of hardening technology of soft and hard grinding with quenching oils. These oils result in a large quenching behavior due to the containing additives, leading to verifiable improvements concerning hardening distortion at some gear forming.

  Essentially following grinding operations are positively impacted,of course.

  Grinding machines of major manufacturers are stiffened, so that higher performance in many cases due to machine quality is possible.

  Manufacturers of grinding tools provide suitable high performance grinding tools.

  These high performance grinding tools are in need of the appropriate high performance oils.

• Rotex^® Spezial 277 and 277-AN as well as
  Rotex^® Spezial V 1217 and 1217-AN

  are high performance grinding and multi functional processing oils, adapted to the high performance grinding bodies on market.

  Generally above mentioned high performance grinding oils have still performance reserves according to grinding performance on market at the moment, which iare mainly dictated from the grinding bodies.

  Basically former mentioned high performance multi functional grinding oils can also be used for soft grinding in the area of

  • hobbing
  • gear planing
  • punching
  • shaving

  in the same manner as for grinding and fulfill in this way the simplification of types, saving costs and support cost-effectiveness at use.