Gears are used in numerous situations. Hero Gears specialize in manufacturing parts for planetary gears, including internal gears and splines. We have for example a flexible robot automatic line for the manufacturing of internal gears with a diameter of up to Ø450mm. As a matter of fact, we have manufactured gears for planetary gearboxes since 1965.
Today, we manufacture both for high-speed planetary gears which change up and run with up to 25.000 revolutions/minute and for more low-speed planetary gears where large torques of up to 100 kNm are being transmitted.
We primarily manufacture internal gears by the method gear shaping. This is an advantage as we can do toothings with a relatively small distance down towards a collar together with wide internal toothings with a small diameter. For this type of gear cutting is usually only needed approx. 5mm of clearance.
Soon we can also provide helical and spur gears with internal and/or external toothing manufactured by the power skiving method. This is a new and very efficient method which is particularly suitable for larger series because of the tooling costs. Furthermore, a larger clearance between toothing and a collar is required due to the machining angle of the cutting tool. Typically about 25mm. Additionally, some geometries may be inappropriate if the chips can´t be evacuated fast enough from the cutting zone, as they will be swirled into the cutting process resulting in surface defects.
Broaching is a third method of efficient manufacturing of internal gears. This method is typically used on smaller parts such as bushings as the broaches are quite expensive. In case of large quantities it is not a problem to use large broaches of up to approx. 250-300 mm diameter.