Because meshing behaviour results from the interaction of several characteristics. Assessing individual drawing dimensions alone is therefore not sufficient.
Plastic Parts for Gear Applications
Gear design starts with the application
A gear cannot be assessed by module alone. Load, speed, mating component, lubrication, installation space, temperature, humidity and acceptable noise levels determine the required gear design. These factors define the material, tolerance concept, gear corrections and inspection characteristics.
Plastic offers advantages such as low weight, corrosion resistance, suitability for dry running and reduced running noise. At the same time, the material is affected by shrinkage, post-mould shrinkage, moisture absorption and temperature. These influences must be taken into account in the design and compensated for where necessary.
Tooth flank, runout and meshing behaviour
In mesh, tooth form, pitch, runout, bore, backlash and contact pattern interact. A single dimensionally accurate characteristic is not enough if the meshing behaviour is incorrect. BERGER therefore assesses gear parts by function – from mould design through to inspection.
Key factors include flash-free tooth flanks, dimensionally stable bores, controlled parting lines, uniform cavity filling and demoulding that does not distort the tooth geometry. Where required, gears are verified by gear rolling inspection or function-related sample checks.
Material selection for friction and wear
Depending on the application, POM, PA or high-performance polymers such as PEEK may be appropriate. Selection depends on friction, wear, temperature, media exposure, moisture behaviour and the mating component. Tribologically modified grades can be beneficial where dry running or service life is a priority.
Material and mould design are closely linked: fibre or filler content, flow direction, gating and mould temperature control influence shrinkage and runout. These effects must be taken into account in the tooling concept.
Mould making for reproducible tooth geometries
Gear parts place high demands on cavity quality, insert changeover, venting, mould temperature control, ejector position and wear behaviour. Even small deviations can affect backlash, noise or service life.
BERGER therefore develops tooling concepts around function-critical gear characteristics, inspectable tolerances and realistic process windows. The aim is consistent meshing behaviour across cavities throughout production.
Frequently asked questions in gear technology
Depending on the load and environmental profile, POM, PA or high-performance polymers such as PEEK may be suitable; the material is selected for the specific application and may include tribologically modified grades where required.
Through material-appropriate design, suitable gating, stable mould temperature control, realistic tolerance concepts and inspection characteristics that take the required backlash in mesh into account.
The design aims to keep friction, wear, noise and backlash under control throughout production and service life. Key factors are the material, tooth geometry, process window and suitable inspection methods.
