Purchase now: Bonfiglioli C 12 2 P 25 P71 B5 Helical Gearbox
Purchase now: Atlantechdrives provides you the C 12 2 P 25 P71 B5, a premium, high-efficiency inline helical gearmotor assembly from Bonfiglioli’s globally recognized C Series. While worm gears are excellent for low-cost 90-degree applications, coaxial helical gears offer vastly superior mechanical efficiency—often exceeding 96%. This means nearly all of your electrical motor power is translated directly into turning torque rather than being lost as radiant heat. The C 12 size is engineered with a 2-stage reduction, achieving a highly versatile 25:1 ratio. Designed with a solid output shaft and a «P» foot-mounted cast-iron housing, it is ready to accept a robust IEC P71 electric motor via a standard B5 mounting flange. This inline gearbox is the ultimate power transmission solution for high-duty-cycle applications such as continuous fluid pumps, heavy-duty agitators, and long linear conveyors where energy efficiency and low operating temperatures are paramount.
Technical Specifications of the C 12 2 P 25 P71 B5
The C series features a highly rigid unibody cast-iron housing that keeps the internal gears perfectly aligned even under severe radial and axial shock loads. The helical gears are case-hardened and profile-ground to ensure incredibly quiet, continuous operation.
- Part Number: C 12 2 P 25 P71 B5
- Gearbox Series: C (Inline Coaxial Helical Gear Reducer)
- Frame Size: 12
- Number of Stages: 2 (Dual reduction gearing)
- Output Configuration: P (Foot-mounted with solid output shaft)
- Reduction Ratio (i): 25:1
- Motor Interface: IEC P71 frame
- Motor Flange Type: B5 (Large standard mounting flange)
Expert Installation Advice: Preventing Fretting Corrosion
Connecting an electric motor to an inline helical gearbox requires strict mechanical hygiene. Expert Tip: When installing your IEC P71 motor into the B5 input flange of the C 12 gearbox, you are inserting a solid steel motor shaft into a steel input hub. During thousands of hours of continuous vibration and microscopic movements, a phenomenon known as «fretting corrosion» inevitably occurs. This reaction creates a rust-like powder that essentially cold-welds the motor shaft to the gearbox bore. Years later, when the electric motor burns out, it will be impossible to separate the motor from the gearbox without destroying both pieces of equipment. To prevent this, you must thoroughly clean the shaft and apply a high-quality anti-seize compound or molybdenum disulfide (MoS2) assembly paste to the motor shaft and the internal keyway before sliding the motor into the input hub.
Maintenance and Overhung Load Management
Unlike worm gears, multi-stage inline helical gears rely heavily on precision front bearing alignment. If you are connecting your driven machine to the solid output shaft of the C 12 via a heavy chain sprocket, a v-belt pulley, or a pinion gear, you must carefully calculate the Overhung Load (Radial Load). If your drive chain is tensioned too tightly, the massive radial force pulls sideways on the gearbox output shaft. Over time, this extreme stress will crush the front bearings and cause the helical gears to misalign and grind. Always position your sprockets as close to the gearbox housing as physically possible to minimize the leverage effect, and strictly adhere to the maximum overhung load ratings specified in the Bonfiglioli engineering manual.
Frequently Asked Questions (FAQs)
Q: What does the «2» mean in the part number C 12 2?
A: The «2» indicates that this gearbox has 2 internal reduction stages (two sets of mating helical gears). This dual-stage architecture allows it to achieve the 25:1 ratio incredibly smoothly while maintaining a high torque capacity in a compact length.
Q: Why choose an inline helical gearbox over a worm gearbox?
A: Helical gearboxes offer significantly higher energy efficiency, produce far less heat, and do not suffer from the sliding friction wear inherent to worm gears. They are ideal for applications running 24/7 where electricity costs and long-term mechanical durability are critical.
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