The assembly and operating status of the worm shaft assembly directly determines the overall performance and reliability of the WPDO135-30-4KW-B reducer. The following is an explanation from seven dimensions.
1. Bearing clearance and axial positioning
Bearing clearance : If the clearance is too large, it will cause radial movement of the shaft system, causing the meshing center distance to fluctuate and the eccentric load to intensify; if the clearance is too small, the internal extrusion friction of the bearing will intensify and heat will become severe. In extreme cases, the bearing will get stuck and the transmission will be directly interrupted.
Axial positioning : Insufficient axial positioning accuracy of the worm will cause uneven distribution of meshing gaps, affecting transmission stability and load uniformity.
2. Meshing clearance and contact spots
Meshing clearance : When the clearance is too large, the tooth surface squeezes and rubs, the oil temperature rises, the oil film ruptures, and adhesive wear is prone to occur, and the load-bearing capacity is significantly reduced; when the clearance is too large, impact loads are easily generated at the moment when the load is reversed, and the tooth surface is repeatedly impacted, which can easily induce fatigue cracks in the tooth root.
Contact spots : The contact spots are not centered or have insufficient area, which will lead to uneven stress distribution on the tooth surface and accelerated local wear.
3. Installation accuracy
Coaxiality : The coaxiality deviation between the worm gear and the worm should be controlled within ±0.02mm; once it exceeds 0.05mm, unilateral contact will occur during meshing, the contact area will be reduced by more than 50%, and the unit tooth surface stress will double, which can easily cause pitting corrosion or plastic deformation.
Flange installation : When the coaxiality deviation between the flange and the output shaft exceeds 0.03mm, additional radial force will be generated, which will aggravate the wear of the worm gear bearing and weaken the support capacity of the shaft system.
4. Lubrication system
Lubricating oil Selection : Use ordinary gear oil instead of special oil for worm gears. The oil film is easy to break and the tooth surfaces are in direct contact. The wear rate is increased by 3 to 5 times, and the load-bearing capacity can be reduced by 50% within 1 to 2 months.
Oil aging and pollution : Special oil contains extreme pressure anti-wear agents and friction reducers, which can form an oil film of 5 to 10 μm on the tooth surface; oil aging or pollution will destroy the oil film and accelerate wear.
5. Load characteristics
Load type : Impact load causes a sudden increase in tooth surface stress, which can easily cause tooth root fracture and tooth surface peeling; periodic alternating loads accelerate material fatigue and shorten the contact fatigue life of gears/worm gears.
Load size : Long-term overloading will cause the tooth surface contact stress to exceed the allowable value, causing the oil film to rupture, causing gluing or pitting; under light load, the oil film is difficult to establish, causing micro-slip wear and reducing transmission efficiency.
6. Materials and manufacturing processes
Material : When the depth of the gear carburized layer is insufficient, the surface layer is easy to peel off, especially under impact load.
Manufacturing process : Tooth profile errors will lead to meshing impact, increased noise, and decreased efficiency; excessive surface roughness will increase the friction coefficient, and the friction loss of the worm gear of the WP series reducer can increase by about 20%.
7. Structural design
Center distance and module : If the center distance is too small, the tooth width and module will be limited, and the load-bearing capacity will be insufficient; if the center distance is too large, the structure will be bulky and the cost will increase (although the heat dissipation area will increase). A small gear module will lead to insufficient strength of the tooth root and easy breakage.
Box rigidity and heat dissipation : Insufficient box rigidity will cause the box to tilt and the gear axis to shift, resulting in eccentric loading; poor heat dissipation design will lead to excessive temperature rise, affecting lubricating oil performance.
